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[ [ "List of comedians" ], [ "Introduction", "A comedian is one who entertains through comedy, such as jokes and other forms of humour.", "Following is a '''list of comedians''', comedy groups, and comedy writers." ], [ "Comedians", "''(sorted alphabetically by surname)''===A===* Rose Abdoo (born 1962)* Raymond Ablack (born 1989)* John Aboud (born 1973)* James Acaster (born 1985)* Jayde Adams (born 1984)* Kev Adams (born 1991)* Lolly Adefope (born 1990)* Pamela Adlon (born 1966)* James Adomian (born 1980)* Scott Adsit (born 1965)* Steve Agee (born 1969)* Alex Agnew (born 1973)* Rubén Aguirre (1934–2016)* Dan Ahdoot (born 1981)* Caroline Aherne (1963-2016)* Ahmed Ahmed (born 1970)* Sohail Ahmed (born 1963)* Franklyn Ajaye (born 1949)* Anna Akana (born 1989)* Malin Akerman (born 1978)* Nawaal Akram (born 1990)* Nasser Al Qasabi (born 1963)* Joe Alaskey (1952–2016)* Carlos Alazraqui (born 1962)* Rory Albanese (born 1977)* Lou Albano (1933-2009)* Eddie Albert (1906-2005)* Tucker Albrizzi (born 2000)* Alan Alda (born 1936)* Jason Alexander (born 1959)* Mo Alexander (born 1970)* Ted Alexandro (born 1969)* Barbara Jo Allen (1906–1974)* Dave Allen (1936–2005)* Gracie Allen (1895–1964)* Leo Allen (born 1972)* Marty Allen (1922–2018)* Steve Allen (1921–2000)* Tim Allen (born 1953)* Woody Allen (born 1935)* Kirstie Alley (1951–2022)* Kevin Allison (born 1970)* Stephanie Allynne (born 1986)* Cristela Alonzo (born 1979)* Jeff Altman (born 1951)* Brian Jordan Alvarez (born 1987)* The Amazing Johnathan (1958–2022)* Utkarsh Ambudkar (born 1983)* Robbie Amell (born 1988)* Mo Amer (born 1981)* John Amos (born 1939)* Megan Amram (born 1987)* Simon Amstell (born 1979)* Morey Amsterdam (1908–1996)* Andrea Anders (born 1975)* Siw Anita Andersen (born 1966)* Amy Anderson (born 1972)* Anthony Anderson (born 1970)* Blake Anderson (born 1984)* Harry Anderson (1952–2018)* James Anderson* Louie Anderson (1953–2022)* Wil Anderson (born 1974)* Eric André (born 1983)* Alex Anfanger (born 1985)* Michael Angarano (born 1987)* Lucia Aniello (born 1983)* Jennifer Aniston (born 1969)* Aziz Ansari (born 1983)* Ant (born 1967)* Dave Anthony (born 1967)* Craig Anton (born 1962)* Judd Apatow (born 1967)* Ingo Appelt (born 1967)* Christina Applegate (born 1971)* John Aprea (born 1941)* Carly Aquilino (born 1990)* Nicole Arbour (born 1985)* Lisa Arch (born 1971)* Roscoe \"Fatty\" Arbuckle (1887–1933)* Geoffrey Arend (born 1978)* Lesley Arfin (born 1979)* Marcella Arguello (born 1985)* Fred Armisen (born 1966)* Alexander Armstrong (born 1970)* Desi Arnaz (1917-1986)* Will Arnett (born 1970)* David A. Arnold (1968–2022)* Tichina Arnold (born 1969)* Tom Arnold (born 1959)* David Arquette (born 1971)* Bea Arthur (1922–2009)* Aaron Aryanpur (born 1978)* Katie Aselton (born 1978)* Erica Ash (born 1977)* Lauren Ash (born 1983)* Annaleigh Ashford (born 1985)* Arthur Askey (1900–1982)* Ed Asner (1929-2021)* Sean Astin (born 1971)* Skylar Astin (born 1987)* Emily Atack (born 1989)* Anthony Atamanuik (born 1974)* Aristotle Athari (born 1991)* Rowan Atkinson (born 1955)* Helen Atkinson-Wood (born 1955)* Dave Attell (born 1965)* Michael \"Atters\" Attree (born 1965)* Scott Aukerman (born 1970)* Phil Austin (1941–2015)* Joe Avati (born 1974)* Awkwafina (born 1988)* Ayelet the Kosher Komic* Dan Aykroyd (born 1952)* Peter Aykroyd (1955–2021)* Damali Ayo (born 1972)* Richard Ayoade (born 1977)* Hank Azaria (born 1964)* Valerie Azlynn (born 1980)===B===* Baba Ali (born 1975)* Dirk Bach (1961–2012)* King Bach (born 1988)* Diedrich Bader (born 1966)* Max Baer Jr. (born 1937)* Ross Bagley (born 1988)* Tim Bagley (born 1957)* Ben Bailey (born 1970)* Bill Bailey (born 1965)* Conrad Bain (1923-2013)* Nick Bakay (born 1959)* Bobbie Baker* Leslie David Baker (born 1958)* Rosebud Baker (born 1985)* Sarah Baker* Dan Bakkedahl (born 1969)* Carlos Balá (1925–2022)* Bob Balaban (born 1945)* Josiane Balasko (born 1950)* Hugo Egon Balder (born 1950)* Alec Baldwin (born 1958)* Lucille Ball (1911–1989)* Kaye Ballard (1925-2019)* Tom Ballard (born 1989)* Colleen Ballinger (born 1986)* Tim Baltz* Maria Bamford (born 1970)* Eric Bana (born 1968)* Elizabeth Banks (born 1974)* Morwenna Banks (born 1961)* Edward Barbanell (born 1977)* Andrea Barber (born 1976)* Celeste Barber (born 1982)* Nate Bargatze (born 1979)* Robert Baril (born 1986/1987)* Ike Barinholtz (born 1977)* Jon Barinholtz (born 1982)* Arj Barker (born 1974)* Ronnie Barker (1929–2005)* Angela Barnes (born 1976)* Ty Barnett (born 1975)* Vince Barnett (1902–1977)* Sandy Baron (1937–2001)* Anita Barone (born 1964)* Roseanne Barr (born 1952)* Julian Barratt (born 1968)* Kenya Barris (born 1974)* Carl Barron (born 1968)* Todd Barry (born 1964)* Mario Barth (born 1972)* Justin Bartha (born 1978)* Jay Baruchel (born 1982)* Frank-Markus Barwasser (born 1960)* Jason Bateman (born 1969)* Angelique Bates (born 1980)* David Batra (born 1972)* Brian Baumgartner (born 1972)* Eric Bauza (born 1979)* Stanley Baxter (born 1926)* Vanessa Bayer (born 1981)* Matthew Baynton (born 1980)* Carter Bays (born 1975)* Aisling Bea (born 1984)* Allyce Beasley (born 1954)* Anne Beatts (1947–2021)* David Beck (born 1970)* Alison Becker (born 1977)* Jürgen Becker (born 1959)* Rob Beckett (born 1986)* Samantha Bee (born 1969)* Joy Behar (born 1942)* Greg Behrendt (born 1963)* Beth Behrs (born 1985)* Jillian Bell (born 1984)* Lake Bell (born 1979)* Tone Bell (born 1983)* W. Kamau Bell (born 1973)* Bill Bellamy (born 1965)* Ryan Belleville (born 1979)* Jim Belushi (born 1954)* John Belushi (1949–1982)* Richard Belzer (1944–2023)* Bea Benaderet (1906–1968)* H. Jon Benjamin (born 1966)* Owen Benjamin (born 1980)* Beck Bennett (born 1984)* Ron Bennington (born 1958)* D.C. Benny* Jack Benny (1894–1974)* Doug Benson (born 1964)* Alec Berg* Edgar Bergen (1903–1978)* Peter Paul Bergman (1939–2012)* Kate Berlant (born 1987)* Milton Berle (1908–2002)* Shelley Berman (1925–2017)* Sandra Bernhard (born 1955)* Matt Berry (born 1974)* Joe Besser (1907–1988)* Matt Besser (born 1967)* Ilka Bessin (born 1971)* Danny Bhoy (born 1976)* Mayim Bialik (born 1975)* Leslie Bibb (born 1974)* Jason Biggs (born 1978)* Jean-Luc Bilodeau (born 1990)* Mike Birbiglia (born 1978)* Simon Bird (born 1984)* Mary Birdsong (born 1968)* Des Bishop (born 1975)* Joey Bishop (1918–2007)* John Bishop (born 1966)* Kevin Bishop (born 1980)* Danielle Bisutti (born 1976)* Ashley Nicole Black (born 1985)* Jack Black (born 1969)* Jordan Black (born 1970)* Lewis Black (born 1948)* Michael Ian Black (born 1971)* Michael Blackson (born 1972)* Hamish Blake (born 1981)* Mel Blanc (1908–1989)* Maria Blasucci (born 1986)* Rich Blomquist (born 1977)* Rachel Bloom (born 1987)* Ben Blue (1901–1975)* Josh Blue (born 1978)* Sarayu Blue (born 1975)* Amir Blumenfeld (born 1983)* John Bluthal (1929-2018)* Raphael Bob-Waksberg (born 1984)* Alonzo Bodden (born 1967)* Steve Bodow* Mirja Boes (born 1971)* Catherine Bohart (born 1988)* Danny Bonaduce (born 1959)* Sue Bond (bprn 1945)* Peter Bonerz (born 1938)* Wigald Boning (born 1967)* Sonny Bono (1935-1998)* Elayne Boosler (born 1952)* Joel Kim Booster (born 1988)* Tato Bores (1927–1996)* Flula Borg (born 1982)* Victor Borge (1909–2000)* Kyle Bornheimer (born 1975)* Alex Borstein (born 1971)* Loren Bouchard (born 1969)* Lilan Bowden (born 1985)* Andrew Bowen (born 1972)* Julie Bowen (born 1970)* Byron Bowers* John Ross Bowie (born 1971)* Max Boyce (born 1945)* Frankie Boyle (born 1972)* Peter Boyle (1935–2006)* Fern Brady* Wayne Brady (born 1972)* Harriet Braine* Zach Braff (born 1975)* Joey Bragg (born 1996)* Patrick Brammall (born 1976)* Jo Brand (born 1957)* Russell Brand (born 1975)* Betsy Brandt (born 1973)* Guy Branum (born 1975)* John Branyan (born 1965) * Matt Braunger (born 1974)* Kurt Braunohler (born 1976)* Ciara Bravo (born 1997)* Daniel Breaker (born 1980)* El Brendel (1890–1964)* Josh Brener (born 1984)* Kevin Brennan (born 1960)* Neal Brennan (born 1974)* David Brenner (1936–2014)* Jim Breuer (born 1967)* Paget Brewster (born 1969)* Alison Brie (born 1982)* Joe Bob Briggs (born 1953)* Patrick Bristow (born 1962)* Janine Brito* Paul Brittain (born 1977)* Doug Brochu (born 1990)* Matthew Broderick (born 1962)* Adam Brody (born 1979)* Jimmy Brogan (born 1948)* Albert Brooks (born 1947)* Foster Brooks (1912–2001)* James L. Brooks (born 1940)* Max Brooks (born 1972)* Mel Brooks (born 1926)* Brother Theodore (1906–2001)* Alan Brough (born 1967)* A. Whitney Brown (born 1952)* Alton Brown (born 1962)* Clancy Brown (born 1959)* Joe E. Brown (1891–1973)* Kevin Brown (born 1972)* Wally Brown (1904–1961)* Cocoa Brown (born 1972)* Yvette Nicole Brown (born 1971)* Carrie Brownstein (born 1974)* Lenny Bruce (1925–1966)* Hazel Brugger (born 1993)* Quinta Brunson (born 1989)* Aidy Bryant (born 1987)* Cubby Bryant (born 1971)* Rob Brydon (born 1965)* Andy Buckley (born 1965)* James Buckley (born 1987)* Jim J. Bullock (born 1955)* Sandra Bullock (born 1964)* Vicco von Bülow (1923–2011)* Rodger Bumpass (born 1951)* Michael Bunin (born 1970)* John Bunny (1863–1915)* Hannibal Buress (born 1983)* Tituss Burgess (born 1979)* Delta Burke (born 1956)* Kathy Burke (born 1964)* Carol Burnett (born 1933)* Bo Burnham (born 1990)* Burnie Burns (born 1973)* George Burns (1896–1996)* Jack Burns (1933–2020)* Regan Burns (born 1968)* Sarah Burns (born 1981)* Bill Burr (born 1968)* Maryedith Burrell (born 1952)* Ty Burrell (born 1967)* Abe Burrows (1910–1985)* James Burrows (born 1940)* Steve Buscemi (born 1957)* Adam Busch (born 1978)* River Butcher (born 1982)* Michelle Buteau (born 1977) * Brett Butler (born 1958)* Red Buttons (1919–2006)* Adam Buxton (born 1969)* Ruth Buzzi (born 1936)* Nicole Byer (born 1986)* John Byner (born 1938)* Amanda Bynes (born 1986)* Ed Byrne (born 1972)* Jason Byrne (born 1972)* Rose Byrne (born 1979)* Steve Byrne (born 1974)===C===* Louis C.K.", "(born 1967)* Vladimir Caamaño (born 1979)* Angelique Cabral (born 1979)* Liz Cackowski* Sid Caesar (1922–2014)* Frank Caeti (born 1973)* Frank Caliendo (born 1975)* Charlie Callas (1924–2011)* Bryan Callen (born 1967)* Frances Callier (born 1969)* Rhona Cameron (born 1965)* Adam Campbell (born 1980)* Archie Campbell (1914–1987)* Bruce Campbell (born 1958)* Craig Campbell (born 1969)* Heather Anne Campbell* Larry Joe Campbell (born 1970)* Neil Campbell * Tisha Campbell (born 1968)* Maria Canals-Barrera (born 1966)* John Candy (1950–1994)* Bobby Cannavale (born 1970)* Kay Cannon (born 1974)* Nick Cannon (born 1980)* Judy Canova (1913–1983)* Mario Cantone (born 1959)* John Caparulo (born 1975)* Blaine Capatch (born 1965)* Lizzy Caplan (born 1982)* Scott Capurro (born 1962)* Matty Cardarople (born 1983)* Linda Cardellini (born 1975)* D'Arcy Carden (born 1980)* Nancy Carell (born 1966)* Steve Carell (born 1962)* Drew Carey (born 1958)* Maggie Carey (born 1975)* George Carl (1916-2000)* George Carlin (1937–2008)* Jordan Carlos (born 1978)* Urzila Carlson (born 1976)* Jerrod Carmichael (born 1987)* Alan Carney (1909–1973)* Art Carney (1918–2003)* Adam Carolla (born 1964)* Alan Carr (born 1976)* Jimmy Carr (born 1972)* Jim Carrey (born 1962)* Rodney Carrington (born 1968)* Pat Carroll (1927-2022)* Carrot Top (Scott Thompson) (born 1965)* Jasper Carrott (born 1945)* Johnny Carson (1925–2005)* Nancy Cartwright (born 1957)* Dana Carvey (born 1955)* Neil Casey (born 1981)* Aya Cash (born 1982)* Cliff Cash (born 1981)* Craig Cash (born 1960)* Michael Cassidy (born 1983)* Dan Castellaneta (born 1957)* Mike Castle (born 1989)* Roy Castle (1932–1994)* Arturo Castro (born 1985)* Jade Catta-Preta* Walter Catlett (1889–1960)* John Catucci (born 1973)* Jo Caulfield (born 1965)* Tony Cavalero (born 1983)* Elise Cavanna (1902-1963)* Dick Cavett (born 1936)* Adam Cayton-Holland (born 1980)* Kyle Cease (born 1977)* Cedric The Entertainer (born 1964)* Wyatt Cenac (born 1976)* Michael Cera (born 1988)* Bülent Ceylan (born 1976)* Jessica Chaffin (born 1982)* Rachel Chagall (born 1952)* Sarah Chalke (born 1976)* Kevin Chamberlin (born 1963)* Emma Chambers (1964–2018)* Jackie Chan (born 1954)* Melanie Chandra (born 1984)* Jay Chandrasekhar (born 1968)* Carol Channing (1921–2019)* Jay Chanoine (born 1986/1987)* Zoë Chao (born 1985)* Omar Chaparro (born 1974)* Charlie Chaplin (1889–1977)* Graham Chapman (1941–1989)* Doug Chappel (born 1975)* Dave Chappelle (born 1973)* Charlamagne tha God (born 1978)* Craig Charles (born 1964)* Josh Charles (born 1971)* Charo* Melanie Chartoff (born 1948)* Charley Chase (1893–1940)* Chevy Chase (born 1943)* Michael Che (born 1983)* Karen Chee (born 1995)* Parvesh Cheena (born 1979)* Richard Cheese (born 1965)* Kristin Chenoweth (born 1968)* Zach Cherry (born 1987)* Cherry Chevapravatdumrong (born 1977)* Ronny Chieng (born 1985)* Autumn Chiklis (born 1993)* Michael Chiklis (born 1963)* Chingo Bling (Pedro Herrera) (born 1979)* Nasir Chinyoti (born 1970)* Ted Chippington (born 1960)* Whitney Chitwood* Henry Cho (born 1962)* John Cho (born 1972)* Margaret Cho (born 1968)* Jessica Chobot (born 1977)* Tommy Chong (born 1938)* Bill Chott (born 1969)* Stephen Chow (born 1962)* Paul Chowdhry (born 1974)* Bridget Christie (born 1971)* Papa CJ (born 1977)* Anthony Clark (born 1964)* Bobby Clark (1888–1960)* Laurence Clark (born 1974)* Mystro Clark (born 1966)* Lenny Clarke (born 1953)* Julian Clary (born 1959)* Andrew \"Dice\" Clay (born 1958)* John Cleese (born 1939)* Ellen Cleghorne (born 1965)* Jemaine Clement (born 1974)* Sean Clements (born 1981)* Del Close (1934-1999)* Jerry Clower (1926–1998)* Andy Clyde (1892–1967)* Michaela Coel (born 1987)* Andy Cohen (born 1968)* Catherine Cohen (born 1991)* Sacha Baron Cohen (born 1971)* Mindy Cohn (born 1966)* Diablo Cody (born 1978)* Sherry Cola (born 1989)* Enrico Colantoni (born 1963)* Stephen Colbert (born 1964)* Coldmirror (born 1984)* Deon Cole (born 1972)* Kim Coles (born 1962)* Gary Coleman (1968–2010)* Jonathan Coleman (1956–2021)* Kelen Coleman (born 1984)* Ryan Coleman (born 1991)* Kim Coles (born 1966)* Bobby Collins (born 1951) * Michelle Collins (born 1981)* Misha Collins (born 1974)* Mo Collins (born 1965)* Sarah Colonna (born 1974)* Michael Colton (born 1975)* Robbie Coltrane (1950–2022)* Ray Combs (1956–1996)* Pat Condell (born 1949)* Kurtis Conner (born 1994)* Frank Conniff (born 1956)* Billy Connolly (born 1942)* Kevin Connolly (born 1974)* Adam Conover (born 1983)* Nina Conti (born 1974)* Tim Conway (1933–2019)* Steve Coogan (born 1965)* Dane Cook (born 1972)* David L. Cook (born 1968)* Matt Cook (born 1984)* Peter Cook (1937–1995)* Josh Cooke (born 1979)* Jennifer Coolidge (born 1961)* Bradley Cooper (born 1975)* Calico Cooper (born 1981)* Pat Cooper (born 1929)* Sarah Cooper (born 1977)* Tommy Cooper (1921–1984)* Alicia Coppola (born 1968)* Bill Corbett (born 1960)* Ronnie Corbett (1930–2016)* Nate Corddry (born 1977)* Rob Corddry (born 1971)* James Corden (born 1978)* Eugene Cordero (born 1978)* Professor Irwin Corey (1914–2017)* Joe Cornish (born 1968)* Rebecca Corry (born 1971)* Bud Cort (born 1948)* Bill Cosby (born 1937)* Lou Costello (1906–1959)* Sue Costello (born 1968)* Camille Cottin (born 1978)* Antony Cotton (born 1975)* Dave Coulier (born 1959)* Jonathan Coulton (born 1970)* Eliza Coupe (born 1981)* Stephanie Courtney (born 1970)* Allen Covert (born 1964)* Courteney Cox (born 1964)* Wally Cox (1924–1973)* Carly Craig (born 1980)* Lavell Crawford (born 1968)* Zach Cregger (born 1980)* Amanda Crew (born 1986)* Terry Crews (born 1968)* Chelsey Crisp (born 1983)* John Crist (born 1984)* Affion Crockett (born 1974)* Ben Crompton (born 1974)* Mackenzie Crook (born 1971)* Norm Crosby (1927–2020)* David Cross (born 1964)* Lucas Cruikshank (born 1993)* Hal Cruttenden (born 1969)* Barry Cryer (1935–2022)* Jon Cryer (born 1965)* Billy Crystal (born 1948)* Ice Cube (born 1969)* Seán Cullen (born 1965)* Whitney Cummings (born 1982)* Dan Cummins (born 1977)* James Cunningham (born 1973)* Mark Curry (born 1961)* Stephen Curry (born 1976)* Jane Curtin (born 1947)* Joan Cusack (born 1962)* John Cusack (born 1966)===D===* Peter F. Dailey (1868–1908)* Charlie Dale (1885–1971)* Karl Dall (1941–2020)* John Francis Daley (born 1985)* Andrew Daly (born 1971)* Jon Daly* Tim Daly (born 1956)* Bill Dana (1924–2017)* Rodney Dangerfield (1921–2004)* Chad Daniels (born 1975)* Greg Daniels (born 1963)* Ted Danson (born 1947)* Dante (born 1970)* Tony Danza (born 1951)* Khalid Abbas Dar (born 1955)* Rhys Darby (born 1974)* Severn Darden (1929–1995)* Vir Das (born 1979)* Hayes Davenport (born 1986)* Jim David (born 1954)* Larry David (born 1947)* Dov Davidoff (born 1973)* Hugh Davidson* Jim Davidson (born 1953)* Pete Davidson (born 1993)* Alan Davies (born 1966)* Greg Davies (born 1968)* DeRay Davis (born 1982)* Jeff B. Davis (born 1973)* Julia Davis (born 1966)* Kristin Davis (born 1965)* LaVan Davis (born 1966)* Lucy Davis (born 1973)* Matt Davis (born 1979)* Tanyalee Davis (born 1970)* Tom Davis (1952–2012)* Richard Dawson (1932–2012)* Les Dawson (1931–1993)* Shane Dawson (born 1988)* Charlie Day (born 1976)* Dennis Day (1916-1988)* Felicia Day (born 1979)* Mikey Day (born 1980)* Andy de la Tour (born 1954)* Frank DeCaro (born 1962)* Gerry Dee (born 1968)* Jack Dee (born 1962) * Rob Deering (born 1972)* Eddie Deezen (born 1957)* Ellen DeGeneres (born 1958)* Vance DeGeneres (born 1954)* Neil Delamere (born 1980)* Rob Delaney (born 1977)* Lea DeLaria (born 1958)* Jessica Delfino (born 1976)* Chris D'Elia (born 1980)* Grey DeLisle (born 1973)* Bianca Del Rio (born 1975)* David DeLuise (born 1971)* Dom DeLuise (1933–2009)* Ivor Dembina (born 1951)* Dr. Demento (born 1941)* Jamie Demetriou (born 1987)* Natasia Demetriou (born 1984)* Lori Beth Denberg (born 1976)* Jamie Denbo (born 1973)* Kat Dennings (born 1986)* Gabrielle Dennis (born 1981)* Hugh Dennis (born 1962)* Les Dennis (born 1953)* Bob Denver (1935–2005)* Joe DeRita (1909–1993)* Joe DeRosa (born 1977)* Portia de Rossi (born 1973)* Zooey Deschanel (born 1980)* Jack DeSena (born 1987)* Mike DeStefano (1966–2011)* Adam DeVine (born 1983)* Danny DeVito (born 1944)* Tommy Dewey (born 1978)* Joyce DeWitt (born 1949)* Eugenio Derbez (born 1962)* Dustin Diamond (1977–2021)* Chris Diamantopoulos (born 1975)* Joey Diaz (born 1963)* Vic DiBitetto (born 1961)* Andy Dick (born 1965)* Daniel Dickey (born 1986)* John Di Domenico (born 1962)* Dominic Dierkes (born 1984)* Richard Digance (born 1949)* Debra DiGiovanni* Phyllis Diller (1917–2012)* Brooke Dillman (born 1966)* Kevin Dillon (born 1965)* Tim Dillon (born 1985)* John DiMaggio (born 1968)* Amelia Dimoldenberg (born 1994)* Paul Dinello (born 1962)* Juan Pablo Di Pace (born 1979)* Nick DiPaolo (born 1962)* Katie Dippold (born 1980)* Andrew Dismukes (born 1995)* Chris Distefano (born 1984)* Olli Dittrich (born 1956)* Gina DiVittorio (born 1995)* Omid Djalili (born 1965)* Anh Do (born 1977)* David Dobrik (born 1996)* Nik Dodani (born 1994)* Ken Dodd (1927–2018)* Mark Dolan (born 1974)* Paul Dooley (born 1928)* Kether Donohue (born 1985)* Lisa Donovan (born 1980)* Tate Donovan (born 1963)* Jimmy Dore (born 1965)* Jon Dore (born 1975)* Doug E. Doug (born 1970)* Beth Dover (born 1978)* John Dowie (born 1950)* Jim Downey (born 1952)* Paul W. Downs (born 1982)* Brian Doyle-Murray (born 1945)* Charlie Drake (1925–2006)* Larry Drake (1949–2016)* Ruth Draper (1884–1956)* Rachel Dratch (born 1966)* Fran Drescher (born 1957)* Marie Dressler (1868–1934)* James Dreyfus (born 1968)* Anna Drezen* Drew Droege* Mike Drucker (born 1984)* Eric Drysdale (born 1969)* Rebecca Drysdale (born 1978/1979)* Rick Ducommun (1952–2015)* Dennis Dugan (born 1946)* Christian Duguay (born 1970)* Josh Duhamel (born 1972)* Jean Dujardin (born 1972)* Clark Duke (born 1985)* Robin Duke (born 1954)* Ryan Drummond (born 1973)* Sandy Duncan (born 1946)* Shane Dundas (born 1959)* Jeff Dunham (born 1962)* Lena Dunham (born 1986)* Barbara Dunkelman (born 1989)* Colton Dunn (born 1977)* Gabe Dunn (born 1988)* Jimmy Dunn* Nora Dunn (born 1952)* Ryan Dunn (1977–2011)* Teala Dunn (born 1996)* Kyle Dunnigan (born 1971)* Jay Duplass (born 1973)* Mark Duplass (born 1976)* Elvis Duran (born 1964)* Jimmy Durante (1893–1980)* Sanjay Dutt (born 1959)* Clea DuVall (born 1977)* Shelley Duvall (born 1949)* Bil Dwyer (born 1962)* Jeff Dye (born 1983)* Rob Dyrdek (born 1974)* Jeremy Dyson (born 1966)===E===* Open Mike Eagle (born 1980)* Jason Earles (born 1977)* John Early (born 1988)* Christine Ebersole (born 1953)* Chris Eckert (born 1986)* Costaki Economopoulos (born 1965)* Ayo Edebiri (born 1995)* Alex Edelman (born 1989)* Eric Edelstein (born 1977)* Barbara Eden (born 1931)* Ade Edmondson (born 1957)* Dean Edwards (born 1970)* Derek Edwards (born 1958)* Ian Edwards* Christian Ehring (born 1972)* Billy Eichner (born 1978)* Hannah Einbinder (born 1995)* Bob Einstein (1942–2019)* Rich Eisen (born 1969)* Ophira Eisenberg (born 1972)* Naomi Ekperigin* Kevin Eldon (born 1959)* Laurie Elliot (born 1971)* Abby Elliott (born 1987)* Bob Elliott (1923–2016)* Bridey Elliott (born 1990)* Chris Elliott (born 1960)* Mary Elizabeth Ellis (born 1979)* Gad Elmaleh (born 1971)* Ethan Embry (born 1978)* Dick Emery (1915–1983)* Harry Enfield (born 1961)* Anke Engelke (born 1965)* Bill Engvall (born 1957)* John Ennis * Mike Epps (born 1970)* Molly Erdman (born 1974)* Heinz Erhardt (1909–1979)* Paco Erhard (born 1975)* Andy Erikson (born 1987)* Leon Errol (1881–1951)* Blaire Erskine (born 1991)* Maya Erskine (born 1987)* Cole Escola (born 1986)* Ennis Esmer (born 1978)* Felipe Esparza (born 1970)* Cameron Esposito (born 1981) * Charles Esten (born 1965)* Chris Evans (born 1966)* Lee Evans (born 1964)* Sean Evans (born 1986)* Bridget Everett (born 1972)* Kenny Everett (1944–1995)* Justine Ezarick (born 1984)===F===* Ana Fabrega (born 1991)* Josh Fadem (born 1980)* Bill Fagerbakke (born 1957)* Damien Fahey (born 1980)* Donald Faison (born 1974)* Jimmy Fallon (born 1974)* Simon Fanshawe (born 1956)* Ali Farahnakian (born 1967)* Anna Faris (born 1976)* Chris Farley (1964–1997)* John Farley (born 1968)* Kevin Farley (born 1965)* Bill Farmer (born 1952)* Simon Farnaby (born 1973)* Jamie Farr (born 1934)* Bobby Farrelly (born 1958)* Peter Farrelly (born 1956)* Negin Farsad (born 1978)* Mitch Fatel (born 1968)* Jon Favreau (born 1966)* Nat Faxon (born 1975)* Isabel Fay (born 1979)* Joey Faye (1909-1997)* Helga Feddersen (1930–1990)* Wayne Federman (born 1959)* Paul Feig (born 1962)* Fortune Feimster (born 1980)* Rachel Feinstein * Ben Feldman (born 1980)* David Feldman* Liz Feldman (born 1977)* Marty Feldman (1934–1982)* Beanie Feldstein (born 1993)* Graham Fellowes (born 1959)* Randy Feltface (born 1980)* Spike Feresten (born 1964)* Craig Ferguson (born 1962)* Don Ferguson (born 1946)* Jay R. Ferguson (born 1974)* Jesse Tyler Ferguson (born 1975)* Keith Ferguson (born 1972)* Shelby Fero (born 1993)* Adam Ferrara (born 1966)* Jerry Ferrara (born 1979)* Will Ferrell (born 1967)* Herbert Feuerstein (1937–2020)* Tina Fey (born 1970)* Nathan Fielder (born 1983)* Noel Fielding (born 1973)* Totie Fields (1930–1978)* W. C. Fields (1880–1946)* Nathan Fillion (born 1971)* Larry Fine (1902–1975)* Chloe Fineman (born 1988)* Christian Finnegan (born 1973)* Dan Finnerty (born 1970)* Kathryn Fiore (born 1979)* Jo Firestone (born 1987)* Jordan Firstman (born 1991)* Jenna Fischer (born 1974)* Joely Fisher (born 1967)* Lang Fisher (born 1980)* Greg Fitzsimmons (born 1966)* Fannie Flagg (born 1944)* Joe Flaherty (born 1941)* Crista Flanagan (born 1976)* Tom Flanigan* Kate Flannery (born 1964)* Charles Fleischer (born 1950)* Chris Fleming (born 1987)* Jim Florentine (born 1964)* Jake Flores* Neil Flynn (born 1960)* Jake Fogelnest (born 1979)* Dan Fogler (born 1976)* Lisa Foiles (born 1986) * Dave Foley (born 1963)* Mick Foley (born 1965)* Paul Foot (born 1973)* Faith Ford (born 1964)* Thomas Mikal Ford (1964–2016)* Matt Forde (born 1982)* Joey Forman (1929–1982)* George Formby (1904–1961)* George Formby Sr. (1875–1921)* Will Forte (born 1970)* Kat Foster (born 1978)* Jermaine Fowler (born 1988)* Jimmy Fowlie (born 1985)* Kirk Fox (born 1969)* Michael J.", "Fox (born 1961)* Zack Fox (born 1990)* Jeff Foxworthy (born 1958)* Jamie Foxx (born 1967)* Redd Foxx (1922–1991)* Leigh Francis (born 1974)* Stewart Francis (born 1964)* Pablo Francisco (born 1974)* Dave Franco (born 1985)* Eduardo Franco (born 1995)* James Franco (born 1978)* Al Franken (born 1951)* Bonnie Franklin (1944–2013)* Marina Franklin* Nelson Franklin (born 1985)* Daniel Franzese (born 1978)* Alice Fraser* William Frawley (1887–1966)* Stan Freberg (1926–2015)* Gavin Free (born 1988)* Travon Free (born 1985)* Martin Freeman (born 1971)* Jared Freid (born 1985)* Dawn French (born 1957)* Matt Frewer (born 1958)* Judah Friedlander (born 1969)* Will Friedle (born 1976)* Budd Friedman (1932–2022)* Jena Friedman* Matt Friend (born 1998)* Annette Frier (born 1974)* Leon Frierson (born 1986)* Don Friesen* Freddie Frinton (1909–1968)* Rebecca Front (born 1964)* David Frost (1939–2013)* Nick Frost (born 1972)* Stephen Fry (born 1957)* Soleil Moon Frye (born 1976)* Pamela Fryman (born 1959)* Daisy Fuentes (born 1966)* John Fugelsang (born 1969)* Rich Fulcher (born 1968)* Ned Fulmer (born 1987)* Ziwe Fumudoh (born 1992)* Ron Funches (born 1983)* Brittany Furlan (born 1986)* Fakkah Fuzz (born 1986)===G===* Eva Gabor (1919-1995)* Jon Gabrus (born 1982)* Josh Gad (born 1981)* Hannah Gadsby (born 1978)* Jim Gaffigan (born 1966)* Mo Gaffney (born 1958)* Daniele Gaither (born 1970)* Johnny Galecki (born 1975)* Zach Galifianakis (born 1969)* Gallagher (1946–2022)* Brian Gallivan* Sue Galloway* Ed Gamble (born 1986)* Megan Ganz (born 1984)* Robert Ben Garant (born 1970)* Jorge Garcia (born 1973)* Billy Gardell (born 1969)* Graeme Garden (born 1943)* Brother Dave Gardner (1926–1983)* Heidi Gardner (born 1983)* Pete Gardner* Tony Gardner (born 1964)* Zarna Garg (born 1975)* Jeff Garlin (born 1962)* Ralph Garman (born 1964)* Paul Garner (1909–2004)* Janeane Garofalo (born 1964)* Teri Garr (born 1944)* Brad Garrett (born 1960)* Kyle Gass (born 1960)* Ana Gasteyer (born 1967)* Alison Gates (born 1988/1989)* Kimmy Gatewood* Mark Gatiss (born 1966)* Joe Gatto (born 1976)* Ryan Gaul (born 1973)* Richard Gautier (1931–2017)* Joey Gay (born 1971)* George Gaynes (1917-2016)* Dustin Gee (1942–1986)* Chris Geere (born 1981)* Brett Gelman (born 1976)* John Gemberling (born 1981)* Genevieve (1920-2004)* Tom Gerhardt (born 1957)* Ricky Gervais (born 1961)* Chris Gethard (born 1980)* Estelle Getty (1923–2008)* Tom Gianas* Marla Gibbs (born 1931)* Erin Gibson* Kathie Lee Gifford (born 1953)* Billy Gilbert (1894–1971)* Rhod Gilbert (born 1968)* Russell Gilbert (born 1959)* Sara Gilbert (born 1975)* Kevin Gillese (born 1980)* Terry Gilliam (born 1940)* Mo Gilligan (born 1988)* Shane Gillis (born 1987)* Paul Gilmartin (born 1963)* Lisa Gilroy* Greg Giraldo (1965–2010)* Adele Givens (born 1960)* Jon Glaser (born 1968)* Nikki Glaser (born 1984)* Ira Glass (born 1959)* Todd Glass (born 1964)* Ilana Glazer (born 1987)* Jackie Gleason (1916–1987)* Tom Gleeson (born 1974)* Ben Gleib (born 1978)* Donald Glover (born 1983)* GloZell (born 1972)* George Gobel (1919–1991)* Godfrey (born 1969)* Janey Godley (born 1961)* Paul Goebel (born 1968)* Loyiso Gola (born 1983)* Judy Gold (born 1962)* Adam Goldberg (born 1970)* Adam F. Goldberg (born 1976)* Andrew Goldberg (born 1978)* Evan Goldberg (born 1982)* Whoopi Goldberg (born 1955)* Brett Goldstein (born 1980)* Jonathan Goldstein (born 1968)* Bobcat Goldthwait (born 1962)* Ian Gomez (born 1965)* Roberto Gómez Bolaños (Chespirito) (1929–2014)* Josh Gondelman (born 1985)* Jami Gong (born 1969)* Ginger Gonzaga (born 1983)* Cuba Gooding Jr. (born 1968)* Omar Gooding (born 1976)* John Goodman (born 1952)* Ken Goodwin (1933–2012)* Dan Goor (born 1975)* Leo Gorcey (1917–1969)* Joseph Gordon-Levitt (born 1981)* Christopher Gorham (born 1974)* Dave Gorman (born 1971)* Frank Gorshin (1933–2005)* Freeman Gosden (1899–1982)* Mark-Paul Gosselaar (born 1974)* Gilbert Gottfried (1955–2022)* Theodore Gottlieb (1906–2001)* Dana Gould (born 1964)* Ray Goulding (1922–1990)* Luba Goy (born 1945)* Jeff Grace* Topher Grace (born 1978)* Boothby Graffoe (born 1962)* Heather Graham (born 1970)* Matt Graham* Kelsey Grammer (born 1955)* Charlie Grandy (born 1974)* Fred Grandy (born 1948)* Corinne Grant (born 1973)* David Grant (born 1956)* Stephen Grant (born 1973)* Judy Graubart (born 1943)* Ari Graynor (born 1983)* Jeff Green (born 1964)* Seth Green (born 1974)* Tom Green (born 1971)* Bryan Greenberg (born 1978)* Shecky Greene (1926–2023)* Max Greenfield (born 1979)* Kathy Greenwood (born 1962)* Judy Greer (born 1975)* Melvin Gregg (born 1988)* Dick Gregory (1932–2017)* James Gregory (born 1946)* Tamsin Greig (born 1966)* Adrian Grenier (born 1976)* Stacey Grenrock-Woods (born 1975)* David Alan Grier (born 1955)* Erik Griffin (born 1972)* Eddie Griffin (born 1968)* Kathy Griffin (born 1960)* Andy Griffith (1926–2012)* Scott Grimes (born 1971)* Todd Grinnell (born 1976)* Charles Grodin (1935–2021)* David Groh (1939–2008)* Kirsten Gronfield (born 1977)* Mary Gross (born 1953)* Michael Gross (born 1947)* Peter Grosz (born 1974)* Rene Gube* Matthew Gray Gubler (born 1980)* Matt Groening (born 1954)* Christopher Guest (born 1948)* Patty Guggenheim (born 1984)* Harvey Guillen (born 1990)* Gary Gulman (born 1970)* Appurv Gupta (born 1990)* Broti Gupta (born 1993)* Annabelle Gurwitch (born 1961)* Björn Gustafsson (born 1986)* Greg Gutfeld (born 1964)* Steve Guttenberg (born 1958)* Deryck Guyler (1914–1999)* Ewen Gilmour (1963–2014)\t===H===* Buddy Hackett (1924–2003)* Tiffany Haddish (born 1979)* Bill Hader (born 1978)* Jenny Hagel* Hallie Haglund (born 1982)* Meredith Hagner (born 1987)* Kathryn Hahn (born 1973)* Tony Hale (born 1970)* Brian Haley (born 1961)* Jack Haley (1897–1979)* Stavros Halkias (born 1989)* Anthony Michael Hall (born 1968)* Brad Hall (born 1958)* Brandon Micheal Hall (born 1993)* Daheli Hall (born 1976)* Huntz Hall (1919–1999)* Rich Hall (born 1954)* Dieter Hallervorden (born 1935)* Evelyn Hamann (1942–2007)* Neil Hamburger (born 1967)* Argus Hamilton* Lloyd Hamilton (1891–1935)* Ryan Hamilton (born 1976)* Jon Hamm (born 1971)* Darrell Hammond (born 1955)* Nick Hancock (born 1962)* Tony Hancock (1924–1968)* Jack Handey (born 1949)* Chelsea Handler (born 1975)* Colin Hanks (born 1977)* Tom Hanks (born 1956)* Alyson Hannigan (born 1974)* Ryan Hansen (born 1981)* Malcolm Hardee (1950–2005)* Mike Harding (born 1944)* Chris Hardwick (born 1971)* Johnny Hardwick (1958–2023)* Jeremy Hardy (1961–2019)* Oliver Hardy (1890–1957)* Allana Harkin* Otis Harlan (1865–1940)* Dan Harmon (born 1973)* Tim Harmston (born 1971/1972)* Valerie Harper (1939–2019)* William Jackson Harper (born 1980)* Neil Patrick Harris (born 1973)* Rachael Harris (born 1968) * Robin Harris (1953–1990)* Blake Harrison (born 1985)* Bret Harrison (born 1982)* Patti Harrison (born 1990)* Hannah Hart (born 1986)* Kevin Hart (born 1979)* Mamrie Hart (born 1983)* Melissa Joan Hart (born 1976)* Miranda Hart (born 1972)* Adam Hartle (born 1979)* Phil Hartman (1948–1998)* Steve Harvey (born 1957)* Murtaza Hassan (1965–2011)* Paul Walter Hauser (born 1986)* Allan Havey (born 1954)* Kali Hawk (born 1986)* Tim Hawkins (born 1968)* Tony Hawks (born 1960)* Goldie Hawn (born 1945)* Charles Hawtrey (1858–1923)* Charles Hawtrey (1914–1988)* Will Hay (1888–1949)* Richard Haydn (1905–1985) * Erinn Hayes (born 1976)* Sean Hayes (born 1970)* Mike Hayley* Natalie Haynes (born 1974)* Ted Healy (1896–1937)* Richard Hearne (1890–1987)* Caleb Hearon (born 1995)* Patricia Heaton (born 1958)* Ian Hecox (born 1987)* Mitch Hedberg (1968–2005)* Jon Heder (born 1977)* Briga Heelan (born 1987)* Bobby Heenan (1943–2017)* Kevin Heffernan (born 1968)* John Heffron (born 1970)* John Hegley (born 1953)* Robert Hegyes (1951–2012)* Tim Heidecker (born 1976)* Jesse Heiman (born 1978)* Hans-Joachim Heist (born 1949)* Simon Helberg (born 1980)* Grace Helbig (born 1985)* Emily Heller (born 1985)* Peter Helliar (born 1975)* Nick Helm (born 1980)* Katherine Helmond (1929–2019)* Ed Helms (born 1974)* Greg Hemphill (born 1969)* Shirley Hemphill (1947–1999)* Sherman Hemsley (1938–2012)* Dickie Henderson (1922–1985)* Christina Hendricks (born 1975)* Elaine Hendrix (born 1970)* Vic Henley (1962–2020)* Marilu Henner (born 1952)* Buck Henry (1930–2020)* Lenny Henry (born 1958)* Mike Henry (born 1964)* John Henton (born 1960)* Dai Henwood (born 1978)* Hugh Herbert (1884–1952)* Christoph Maria Herbst (born 1966)* Tim Herlihy (born 1966)* David Herman (born 1967)* Thomas Hermanns (born 1963)* Marcello Hernandez (born 1997)* Richard Herring (born 1967)* Seth Herzog (born 1970)* Howard Hesseman (1940–2022)* Bill Hicks (1961–1994)* Ryan Higa (born 1990)* David Anthony Higgins (born 1961)* John Michael Higgins (born 1963)* Maeve Higgins* Steve Higgins (born 1963)* Dieter Hildebrandt (1927–2013)* Amy Hill (born 1953)* Bec Hill (born 1986)* Benny Hill (1924–1992)* Dave Hill (born 1974)* Dulé Hill (born 1975)* Ed Hill (born 1984)* Harry Hill (born 1964)* Jonah Hill (born 1983)* Martina Hill (born 1974)* Melinda Hill (born 1972)* Murray Hill* Thelma Hill (1906-1938)* Tymberlee Hill* Jeff Hiller* Adam Hills (born 1970)* Tony Hinchcliffe (born 1984)* Cheryl Hines (born 1965)* Gregory Hines (1946–2003)* Skip Hinnant (born 1940)* Michael Hitchcock (born 1958)* Thora Hird (1911-2003)* Justin Hires (born 1985)* Judd Hirsch (born 1935)* Matt Hobby (born 1985)* Stephanie Hodge (born 1956)* Jessy Hodges (born 1986)* John Hodgman (born 1971)* Joel Hodgson (born 1960)* Jackie Hoffman (born 1960)* Robby Hoffman* Gaby Hoffmann (born 1982)* Steve Hofstetter (born 1979)* Chris Hogan (born 1970)* Paul Hogan (born 1939)* Siobhan Fallon Hogan (born 1961)* Amy Hoggart (born 1986)* Corey Holcomb (born 1969)* Dominic Holland (born 1967)* Mary Holland (born 1985)* Vanessa Hollingshead* Stanley Holloway (1890–1982)* Anders Holm (born 1981)* Chelsea Holmes (born 1993/1994)* Dave Holmes (born 1971)* Eamonn Holmes (born 1959)* Jessica Holmes (born 1973)* Pete Holmes (born 1979)* Todd Holoubek (born 1969)* Lauren Holt (born 1991)* Helen Hong (born 1985)* Brian Hooks (born 1974)* Jan Hooks (1957–2014)* Bob Hope (1903–2003)* Sharon Horgan (born 1970)* Kenneth Horne (1907–1969)* Mathew Horne (born 1978)* Alex Kapp Horner (born 1969)* David Hornsby (born 1975)* Don Hornsby (1924–1950)* Lutz van der Horst (born 1975)* Edward Everett Horton (1886–1970)* Richard Steven Horvitz (born 1966)* Curly Howard (1903–1952)* Frankie Howerd (1917–1992)* Ken Howard (1944–2016)* Kyle Howard (born 1978)* Moe Howard (1897–1975)* Ron Howard (born 1954)* Russell Howard (born 1980)* Shemp Howard (1895–1955)* Kirby Howell-Baptiste (born 1987)* Glenn Howerton (born 1976)* Lil Rel Howery (born 1979)* Jeremy Hotz (born 1966)* Roy Hudd (1936–2020)* Oliver Hudson (born 1976)* Rob Huebel (born 1969)* Akilah Hughes (born 1989)* Dave Hughes (born 1970)* John Hughes (1950–2009)* London Hughes (born 1989)* Sean Hughes (1965–2017)* Steve Hughes (born 1966)* D. L. Hughley (born 1963)* Daniel Humbarger* Barry Humphries (1934–2023)* Bonnie Hunt (born 1961)* Brendan Hunt (born 1972)* Bill Hunter (1940–2011)* Reginald D. Hunter (born 1969)* David Huntsberger (born 1979)* Carl Hurley (born 1941)* Elizabeth Hurley (born 1965)* Lillian Hurst (born 1943)* Jake Hurwitz (born 1985)* Jon Hurwitz (born 1977)* Brian Huskey (born 1968)* Toby Huss (born 1966)* Warren Hutcherson (born 1963)* Betty Hutton (1921–2007)* Jessica Hynes (born 1972)===I===* Paul Iacono (born 1988)* Sal Iacono (born 1971)* Armando Iannucci (born 1963)* Eric Idle (born 1943)* Eddie Ifft (born 1974)* Gabriel Iglesias (born 1976)* Sabrina Impacciatore (born 1968)* Robin Ince (born 1969)* Neil Innes (1944–2019)* Scott Innes (born 1966)* Tino Insana (1948–2017)* Dom Irrera (born 1948)* Bill Irwin (born 1950)* Harith Iskander (born 1966)* Eddie Izzard (born 1962)===J===* Brandon T. Jackson (born 1984)* Marc Evan Jackson (born 1970)* Shantira Jackson* Victoria Jackson (born 1959)* Manny Jacinto (born 1987)* Gillian Jacobs (born 1982)* Abbi Jacobson (born 1984)* Javed Jaffrey (born 1963)* T.J. Jagodowski (born 1971)* Gerburg Jahnke (born 1955)* Sabrina Jalees (born 1985)* Billy T. James (1948–1991)* Elis James (born 1980)* Janelle James* Kevin James (born 1965)* Jameela Jamil (born 1986)* Gary Janetti (born 1966)* Alia Janine (born 1978)* Michael Patrick Jann (born 1970)* Allison Janney (born 1959)* Zoe Jarman (born 1982)* Jay Jason (1915–2001)* Sam Jay (born 1982)* Kavin Jayaram (born 1980)* Jim Jefferies (born 1977)* Richard Jeni (1957–2007)* Ken Jeong (born 1969)* Anthony Jeselnik (born 1978)* Geri Jewell (born 1956)* Penn Jillette (born 1955)* Maz Jobrani (born 1972)* Jake Johannsen (born 1960)* Anjelah Johnson (born 1982)* Anthony Johnson (1966–2021)* Chic Johnson (1891–1962)* Jake Johnson (born 1978)* James Austin Johnson (born 1989)* Josh Johnson (born 1990)* Nicole Randall Johnson (born 1973)* Punkie Johnson (born 1985)* Rebekka Johnson* Slink Johnson* Zainab Johnson* Jay Johnston (born 1968)* Kristen Johnston (born 1967)* Angus T. Jones (born 1993)* Brandon Scott Jones (born 1984)* \"Hamburger\" Jones* Jason Jones (born 1967)* Leslie Jones (born 1967)* Luka Jones (born 1975)* Matt Jones (born 1981)* Orlando Jones (born 1968)* Rashida Jones (born 1976)* Terry Jones (1942–2020)* Leslie Jordan (1955–2022)* Lesley Joseph (born 1945)* Colin Jost (born 1982)* Mitra Jouhari (born 1992)* Jesse Joyce (born 1978)* Mario Joyner (born 1961)* Mike Judge (born 1962)* Andy Juett (born 1977)* Phill Jupitus (born 1962)===K===* Daniel Kaluuya (born 1989)* Madeline Kahn (1942–1999)* Bess Kalb (born 1987)* Jamie Kaler (born 1964)* Mindy Kaling (born 1979)* Adhir Kalyan (born 1983)* Carol Kane (born 1952)* Russell Kane (born 1975)* Gabe Kaplan (born 1945)* Myq Kaplan (born 1978)* JP Karliak (born 1981)* Uğur Rıfat Karlova (born 1980)* Ian Karmel (born 1984)* Richard Karn (born 1956)* Aaron Karo (born 1979)* Jensen Karp (born 1979)* Moshe Kasher (born 1979)* Jackie Kashian (born 1963)* John Kassir (born 1957)* Chris Kattan (born 1970)* Jonathan Katz (born 1946)* Mickey Katz (1909–1985)* Andy Kaufman (1949–1984)* Julie Kavner (born 1950)* Peter Kay (born 1973)* Phil Kay (born 1969)* Spencer Kayden (born 1971)* Danny Kaye (1911–1987)* Paul Kaye (born 1964)* Stubby Kaye (1918–1997)* Samson Kayo (born 1991/1992)* Zoe Kazan (born 1983)* Molly Kearney (born 1992)* Diane Keaton (born 1946)* Michael Keaton (born 1951)* Carolin Kebekus (born 1980)* John Keister (born 1956)* Peter Kelamis (born 1967)* Echo Kellum (born 1982)* Chris Kelly (born 1983)* Frank Kelly (1938–2016)* Martha Kelly (born 1968)* Patsy Kelly (1910–1981)* Robert Kelly (born 1970)* Pert Kelton (1907–1968)* Ellie Kemper (born 1980)* Suzanna Kempner (born 1985)* Harriet Kemsley (born 1987)* Sarah Kendall (born 1976)* Edgar Kennedy (1890–1948)* Graham Kennedy (1934–2005)* Jamie Kennedy (born 1970)* Mimi Kennedy (born 1948)* Tom Kennedy (1885–1965)* Trey Kennedy* Kerri Kenney-Silver (born 1970)* Jon Kenny (born 1957)* Tom Kenny (born 1962)* Sean Kent* Humphrey Ker (born 1982)* Langston Kerman (born 1987)* Hape Kerkeling (born 1964)* Michael Kessler (born 1967)* Keegan-Michael Key (born 1971)* Kristin Key (born 1980)* Sarah Keyworth (born 1993)* Amanullah Khan (born 1970)* Guz Khan (born 1986)* Shappi Khorsandi (born 1973)* The Kid Mero (born 1983)* Ford Kiernan (born 1962)* Laura Kightlinger (born 1969)* Pat Kilbane (born 1969)* Craig Kilborn (born 1962)* Taran Killam (born 1982)* Laurie Kilmartin (born 1965)* Jimmy Kimmel (born 1967)* Kyle Kinane (born 1976)* Richard Kind (born 1956)* Andy Kindler (born 1956)* Alan King (1927–2004)* Anthony King* Dave King (1929-2002)* Georgia King (born 1986)* Jaime King (born 1979)* Matt King (born 1968)* Michael Patrick King (born 1954)* Nika King* Sam Kinison (1953–1992)* Greg Kinnear (born 1963)* Roy Kinnear (1934-1988)* Kathy Kinney (born 1954)* Angela Kinsey (born 1971)* Bruno Kirby (1949–2006)* Bill Kirchenbauer (born 1953)* Jen Kirkman (born 1974)* Matt Kirshen (born 1980)* Takeshi Kitano (born 1947)* Jonathan Kite (born 1979)* Daniel Kitson (born 1977)* Roger Kitter (1949-2015)* Julie Klausner (born 1978)* Chris Klein (born 1979)* Jessi Klein (born 1975)* Robert Klein (born 1942)* Jordan Klepper (born 1979)* Kevin Kline (born 1947)* Jack Klugman (1922–2012)* Jessica Knappett (born 1984)* Christopher Knight (born 1957)* Jak Knight (1993–2022)* Ted Knight (1923–1986)* Wayne Knight (born 1955)* Don Knotts (1924–2006)* Christy Knowings (born 1980)* Johnny Knoxville (born 1971)* Chris Knutson* Christine Ko (born 1988)* Cody Ko (born 1990)* Olga Koch* David Koechner (born 1962)* Stephanie Koenig (born 1987)* Matt Koff* Gaby Köster (born 1961)* Michael Koman (born 1977)* Hari Kondabolu (born 1982)* Dada Kondke (1932–1998)* Anna Konkle (born 1987)* Jenni Konner (born 1971)* Lynne Koplitz (born 1969)* Harvey Korman (1927–2008)* Annie Korzen (born 1938)* Liza Koshy (born 1996)* Michael Kosta (born 1979)* Ernie Kovacs (1919–1962)* Jo Koy (born 1971)* Lindsey Kraft (born 1980)* Jane Krakowski (born 1968)* Eric Allan Kramer (born 1962)* John Krasinski (born 1979)* Diether Krebs (1947–2000)* Bert Kreischer (born 1972)* Howard Kremer (born 1971)* Jonathan Krisel (born 1979)* Kurt Krömer (born 1974)* Nick Kroll (born 1978)* Mike Krüger (born 1951)* David Krumholtz (born 1978)* Esther Ku (born 1980)* Lisa Kudrow (born 1963)* Akshay Kumar (born 1967)* Nish Kumar (born 1985)* Elvira Kurt (born 1961)* Swoosie Kurtz (born 1944)* Ashton Kutcher (born 1978)* Eugenia Kuzmina (born 1987)===L===* Tyler Labine (born 1978)* Jake Lacy (born 1985)* Preston Lacy (born 1969)* Cathy Ladman* Jon Lajoie (born 1980)* Don Lake (born 1956)* Patricia Lake (1919-1993)* Maurice LaMarche (born 1958)* Leah Lamarr (born 1988)* Phil LaMarr (born 1967)* Lisa Lampanelli (born 1961)* Amy Landecker (born 1969)* David Lander (1947–2020)* Steve Landesberg (1936–2010)* Matteo Lane (born 1982)* Nathan Lane (born 1956)* Richard Lane (1899–1982)* Harry Langdon (1894–1944)* Artie Lange (born 1967)* Ted Lange (born 1948)* Chris Langham (born 1949)* Ruth Langsford (born 1960)* Beth Lapides* Lauren Lapkus (born 1985)* Rocky LaPorte* John Larroquette (born 1947)* Larry the Cable Guy (born 1963)* Jay Larson* Queen Latifah (born 1970)* Stan Laurel (1890–1965)* Dan Lauria (born 1947)* Hugh Laurie (born 1959)* Ed Lauter (1938–2013)* Tony Law (born 1969)* Bill Lawrence (born 1968)* Carolyn Lawrence (born 1967)* Doug Lawrence (born 1969)* Martin Lawrence (born 1965)* Mike Lawrence (born 1983)* Vicki Lawrence (born 1949)* Maggie Lawson (born 1980)* Cloris Leachman (1926–2021)* Denis Leary (born 1957)* Matt LeBlanc (born 1967)* Annie Lederman (born 1983)* Andy Lee (born 1981)* Bobby Lee (born 1972)* C.S.", "Lee (born 1971)* Greg Lee (born 1962)* Hana Mae Lee (born 1988)* Jamie Lee (born 1983)* Jason Lee (born 1970)* Raquel Lee (born 1986)* Rex Lee (born 1969)* Stewart Lee (born 1968)* Terence Lee (born 1964)* Andrew Leeds (born 1981)* Jane Leeves (born 1961)* Michael Legge (born 1968)* Natasha Leggero (born 1974)* Jay Leggett (1963–2013)* John Leguizamo (born 1964)* John Lehr (born 1965)* Tom Lehrer (born 1928)* Carol Leifer (born 1956)* Ismo Leikola (born 1979)* Steve Lemme (born 1968)* Jack Lemmon (1925–2001)* Nancy Lenehan (born 1953)* Tom Lenk (born 1976)* Thomas Lennon (born 1970)* Jay Leno (born 1950)* Jack E. Leonard (1910–1973)* Chauncey Leopardi (born 1981)* Yassir Lester (born 1984)* James Lesure (born 1970)* David Letterman (born 1947)* Sam Levenson (1911–1980)* Johnny Lever (born 1950)* Zachary Levi (born 1980)* Kristine Levine (born 1970)* Samm Levine (born 1982)* Cash Levy* Dan Levy (born 1981)* Dan Levy (born 1983)* Eugene Levy (born 1946)* Clea Lewis (born 1965)* Jenifer Lewis (born 1957)* Jerry Lewis (1926–2017)* Kimrie Lewis (born 1982)* Phill Lewis (born 1968)* Richard Lewis (born 1947)* Robert Q. Lewis (1921-1991)* Shari Lewis (1933-1998)* Vicki Lewis (born 1960)* Kobi Libii* Paul Lieberstein (born 1967)* Wendy Liebman (born 1961)* Gabe Liedman (born 1982)* Judith Light (born 1949)* Lil Dicky (born 1988)* Lil' JJ (born 1990)* Matthew Lillard (born 1970)* Hal Linden (born 1931)* Riki Lindhome (born 1979)* Joe Lipari (born 1979)* Maureen Lipman (born 1946)* Joe List (born 1982)* Zoe Lister-Jones (born 1982)* Ian Lithgow (born 1972)* John Lithgow (born 1945)* Luciana Littizzetto (born 1964)* Ralf Little (born 1980)* Rich Little (born 1938)* Rob Little (born 1972)* Steve Little (born 1972)* Beth Littleford (born 1968)* Lucy Liu (born 1968)* Christopher Lloyd (born 1938)* Harold Lloyd (1893–1971)* Roger Lloyd-Pack (1944-2014)* Joe Lo Truglio (born 1970)* Daniel Lobell (born 1982/1983)* Sean Lock (1963–2021)* Greg London (born 1966)* Jay London (born 1966)* Josie Long (born 1982)* Justin Long (born 1978)* Shelley Long (born 1949)* Michael Longfellow (born 1994)* Andrés López (born 1971)* George Lopez (born 1961)* Mario Lopez (born 1973)* Dave Losso* Julia Louis-Dreyfus (born 1961)* Faizon Love (born 1968)* Jason Love* Judi Love (born 1980)* Loni Love (born 1971)* Jon Lovett (born 1982)* Jon Lovitz (born 1957)* Rob Lowe (born 1964)* Chris Lowell (born 1984)* Britt Lower (born 1985)* Adam Lowitt* Mark Lowry (born 1958)* Matt Lucas (born 1974)* Luenell (born 1959)* Joanna Lumley (born 1946)* Eric Lutes (born 1962)* John Lutz (born 1973)* Joe Lycett (born 1988)* Desi Lydic (born 1981)* Carmen Lynch (born 1972)* Drew Lynch (born 1991)* Jane Lynch (born 1960)* Katherine Lynch (born 1972)* Stephen Lynch (born 1971)* Paul Lynde (1926–1982)* Chelcie Lynn* Darci Lynne (born 2004)* Melanie Lynskey (born 1977)* Natasha Lyonne (born 1979)===M===* Moms Mabley (1894–1975)* Bernie Mac (1957–2008)* Hayes MacArthur (born 1977)* Scott MacArthur (born 1979)* Norm Macdonald (1959–2021)* Rachael MacFarlane (born 1976)* Seth MacFarlane (born 1973)* Gavin MacLeod (1931-2021)* Fred MacMurray (1908-1991)* Justina Machado (born 1972)* April Macie (born 1975)* Laird Macintosh (born 1962)* Charles Mack (1888–1934)* Lee Mack (born 1968)* Mary Mack (born 1975)* Doon Mackichan (born 1962)* Chris Maddock (born 1977/1978)* Kathleen Madigan (born 1965)* Al Madrigal (born 1971)* Scooter Magruder (born 1988)* Sean Maguire (born 1976)* Naveed Mahbub* Bill Maher (born 1956)* Bruce Mahler (born 1950)* Bobby Mair (born 1986)* Shaun Majumder (born 1972)* Wendie Malick (born 1950)* Joshua Malina (born 1966)* Keith Malley (born 1974)* Joe Mande (born 1983)* David Mandel (born 1970)* Howie Mandel (born 1955)* Dylan Mandlsohn (born 1980/1981)* Aasif Mandvi (born 1966)* Jason Manford (born 1981)* Stephen Mangan (born 1968)* Jonathan Mangum (born 1971)* Sunita Mani (born 1986)* Sebastian Maniscalco (born 1973)* Leslie Mann (born 1972)* Charlie Manna (1920–1970)* Bernard Manning (1930–2007)* Taryn Manning (born 1978)* J.P. Manoux (born 1969)* Jason Mantzoukas (born 1972)* Alec Mapa (born 1965)* Jenna Marbles (born 1986)* Joseph Marcell (born 1948)* Cheech Marin (born 1946)* Ken Marino (born 1968)* Pigmeat Markham (1904–1981)* Alfred Marks (1921-1996)* Bob Marley (born 1967)* Marc Maron (born 1963)* Ross Marquand (born 1981)* Zoë Coombs Marr* Elizabeth Marrero (born 1963)* Dylan Marron (born 1988)* Betty Marsden (1919–1998)* James Marsden (born 1973)* Garry Marshall (1934–2016)* Penny Marshall (1943–2018)* Andrea Martin (born 1947)* Dean Martin (1917–1995)* Demetri Martin (born 1973)* Dick Martin (1922–2008)* Duane Martin (born 1965)* Mae Martin (born 1987)* Millicent Martin (born 1934)* Steve Martin (born 1945)* Adrian Martinez (born 1972)* Jackie Martling (born 1947)* Karen Maruyama (born 1958)* Chico Marx (1887–1961)* Groucho Marx (1890–1977)* Gummo Marx (1892–1977)* Harpo Marx (1888–1964)* Patricia Marx* Zeppo Marx (1901–1979)* Jackie Mason (1928–2021)* Christopher Massey (born 1990)* Kyle Massey (born 1991)* Christopher Masterson (born 1980)* Danny Masterson (born 1976)* Sean Masterson* Rose Matafeo (born 1992)* Ross Mathews (born 1979)* Shane Mauss (born 1980)* Andrew Maxwell (born 1974)* Elaine May (born 1932)* Ralphie May (1972–2017)* Rik Mayall (1958–2014)* Wendy Maybury (born 1974/1975)* Bill Maynard (1928-2018)* X Mayo* Jayma Mays (born 1979)* Alphonso McAuley (born 1984)* Jack McBrayer (born 1973)* Danny McBride (born 1976)* Jenny McCarthy (born 1972)* Matt McCarthy (born 1979)* Melissa McCarthy (born 1970)* Dave McCary (born 1985)* Rue McClanahan (1934–2010)* Fancy Ray McCloney* Matthew McConaughey (born 1969)* Brian McConnachie (born 1942)* Eric McCormack (born 1963)* Dan McCoy (born 1978)* Michael McCullers (born 1971)* Bruce McCulloch (born 1961)* Julian McCullough (born 1979)* Paul McCullough (1883–1936)* Paul McDermott (born 1962)* Josh McDermitt (born 1978)* Heather McDonald (born 1970)* Kevin McDonald (born 1961)* Michael McDonald (born 1964)* Charlie McDonnell (born 1990)* Charlie McDowell (born 1983)* Rob McElhenney (born 1977)* Griffin McElroy (born 1987)* Justin McElroy (born 1980)* Travis McElroy (born 1983)* Bonnie McFarlane (born 1973)* Caitlin McGee (born 1988)* John C. McGinley (born 1959)* Ted McGinley (born 1958)* Joel McHale (born 1971)* Jan McInnis* Michael McIntyre (born 1976)* Adam McKay (born 1968)* Antoine McKay (born 1970)* Michael McKean (born 1947)* Jessica McKenna (born 1987)* Bret McKenzie (born 1976)* Brian McKim* Mark McKinney (born 1959)* Kate McKinnon (born 1984)* Des McLean* Wendi McLendon-Covey (born 1969)* Pauline McLynn (born 1962)* Ed McMahon (1923–2009)* Rove McManus (born 1974)* Don McMillan* Ryan McPartlin (born 1975)* Vaughn Meader (1936–2004)* Tim Meadows (born 1961)* Kevin Meaney (1956–2016)* Anne Meara (1929–2015)* Matt Meese (born 1983)* Keyla Monterroso Mejia (born 1998)* Fred Melamed (born 1956)* Stuttering John Melendez (born 1965)* Jill-Michele Melean (born 1979)* Doug Mellard* Carlos Mencia (born 1967)* Rick Mercer (born 1969)* Stephen Merchant (born 1974)* Dave Merheje* Liz Meriwether (born 1981)* Paul Merton (born 1957)* Chris Messina (born 1974)* Debra Messing (born 1968)* Laurie Metcalf (born 1955)* Art Metrano (1936–2021)* Kurt Metzger (born 1977)* Jason Mewes (born 1974)* Breckin Meyer (born 1974)* Josh Meyers (born 1976)* Seth Meyers (born 1973)* Florinda Meza (born 1948)* Shaun Micallef (born 1962)* Felicia Michaels (born 1964)* Lorne Michaels (born 1944)* Kate Micucci (born 1980)* Thomas Middleditch (born 1982)* Bette Midler (born 1945)* A.D.", "Miles (born 1971)* John Milhiser (born 1981)* Cristin Milioti (born 1985)* Ben Miller (born 1966)* Christa Miller (born 1964)* Dennis Miller (born 1953)* Karlous Miller (born 1983)* Larry Miller (born 1953)* Marilyn Suzanne Miller (born 1950)* Max Miller (1894–1963)* Murray Miller (born 1976)* T.J. Miller (born 1981)* Sarah Millican (born 1975)* Spike Milligan (1918–2002)* Florence Mills (1896-1927)* Andy Milonakis (born 1976)* Tim Minchin (born 1975)* Brian Miner (born 1981)* Hasan Minhaj (born 1985)* Jerry Minor (born 1969)* Dan Mintz (born 1981)* Christopher Mintz-Plasse (born 1989)* Matt Mira (born 1983)* Lin-Manuel Miranda (born 1980)* Eugene Mirman (born 1975)* David Mitchell (born 1974)* Duke Mitchell (1926-1981)* Finesse Mitchell (born 1972)* Kel Mitchell (born 1978)* Mike Mitchell (born 1982)* Aditi Mittal* Michael Mittermeier (born 1966)* Katy Mixon (born 1981)* Colin Mochrie (born 1957)* Mehran Modiri (born 1967)* Alex Moffat (born 1982)* Kausar Mohammed (born 1992)* Nick Mohammed (born 1980)* Jay Mohr (born 1970)* Al Molinaro (1919–2015)* Richard Moll (1943–2023)* John Moloney* Dominic Monaghan (born 1976)* Mo'Nique (born 1967)* Bob Monkhouse (1928–2003)* Lucy Montgomery (born 1975)* Kyle Mooney (born 1984)* Nate Mooney* Paul Mooney (1941–2021)* Christina Moore (born 1973)* Dudley Moore (1935–2002)* Mary Tyler Moore (1936–2017)* Michael Moore (born 1954)* Phil Moore (born 1961)* Rudy Ray Moore (1927–2008)* Tim Moore (1887–1958)* Trevor Moore (1980–2021)* Victor Moore (1876–1962)* Maribeth Monroe (born 1978)* Natalie Morales (born 1985)* Dylan Moran (born 1971)* George Moran (1881–1949)* Polly Moran (1883–1952)* Rick Moranis (born 1953)* Dave Mordal (born c. 1950–1960s)* Eric Morecambe (1926–1984)* Harley Morenstein (born 1985)* Dermot Morgan (1952–1998)* Elliott Morgan (born 1987)* John Morgan (1930–2004)* Leanne Morgan (born 1965)* Matt Morgan (born 1977)* Tracy Morgan (born 1968)* Brent Morin (born 1986)* Pat Morita (1932–2005)* Sam Morril (born 1986)* Brad Morris (born 1975)* Chris Morris (born 1965)* Garrett Morris (born 1937)* Lamorne Morris (born 1983)* Seth Morris (born 1970)* Eleanor Morton* Lew Morton* Laci Mosley (born 1991)* Don Most (born 1953)* Zero Mostel (1915–1977)* José Sánchez Mota (born 1965)* Tahj Mowry (born 1986)* Bobby Moynihan (born 1977)* Teacher Mpamire (born 1983)* John Mulaney (born 1982)* Martin Mull (born 1943)* Megan Mullally (born 1958)* Mitch Mullany (1968–2008)* Neil Mullarkey (born 1961)* Annie Mumolo (born 1973)* Noah Munck (born 1996)* Olivia Munn (born 1980)* Simon Munnery (born 1967)* Richard Murdoch (1907–1990)* Annie Murphy (born 1986)* Charlie Murphy (1959–2017)* Colin Murphy (born 1968)* Eddie Murphy (born 1961)* Kevin Murphy (born 1956)* Larry Murphy (born 1972)* Morgan Murphy (born 1981)* Noel Murphy (born 1961)* Al Murray (born 1968)* Bill Murray (born 1950)* James Murray (born 1976)* Jan Murray (1916–2006)* Joel Murray (born 1963)* Lorenzo Music (1937–2001)* Erik Myers* Mike Myers (born 1963)* Arden Myrin (born 1973)===N===* Jim Nabors (1930–2017)* Suzy Nakamura (born 1968)* Kevin Nalty (born 1969)* Leonardo Nam (born 1979)* Philomaine Nanema (born 1982) * Aparna Nancherla (born 1982)* Kumail Nanjiani (born 1978)* Paul Nardizzi* Jason Narvy (born 1974)* Amber Nash (born 1977)* Jason Nash (born 1973)* Niecy Nash (born 1970)* Rex Navarette (born 1969)* Henry Naylor (born 1966)* Kunal Nayyar (born 1981)* Cliff Nazarro (1904–1961)* Kevin Nealon (born 1953)* Lucas Neff (born 1985)* Taylor Negron (1957–2015)* Jamar Neighbors (born 1986)* Bob Nelson (born 1958)* Bridget Jones Nelson (born 1964)* Craig T. Nelson (born 1944)* Michael J. Nelson (born 1964)* Ozzie Nelson (1906-1975)* Nick Nemeroff (1989–2022)* Felipe Neto* Kyle Newacheck (born 1984)* Bob Newhart (born 1929)* Griffin Newman (born 1989)* Laraine Newman (born 1952)* Robert Newman (born 1964)* Tawny Newsome (born 1983)* Bert Newton (1938–2021)* Lee Newton (born 1985)* Desus Nice (born 1981)* Phil Nichol* Brittani Nichols (born 1988)* Mike Nichols (1931–2014)* Leslie Nielsen (1926–2010)* Trevor Noah (born 1984)* Ross Noble (born 1976)* Coleen Nolan (born 1965)* Henry Normal (born 1956)* Hayley Marie Norman (born 1989)* Mark Normand (born 1983)* Austin North (born 1996)* Nolan North (born 1970)* Graham Norton (born 1963)* Jim Norton (born 1968)* Duncan Norvelle (born 1958)* Tig Notaro (born 1971)* B. J. Novak (born 1979)* Jacqueline Novak (born 1982)* Kayvan Novak (born 1978)* Don Novello (born 1943)* Dieter Nuhr (born 1960)* Luke Null (born 1990)* Whindersson Nunes (born 1995)* Oscar Nunez (born 1958)* Ego Nwodim (born 1988)* Bill Nye (born 1955)* Louis Nye (1913–2005)===O===* Jay Oakerson (born 1977)* Matt Oberg (born 1976)* Dara Ó Briain (born 1972)* Conan O'Brien (born 1963)* Mike O'Brien (born 1976)* Jerry O'Connell (born 1974)* Ryan O'Connell (born 1986)* Carroll O'Connor (1924–2001)* Des O'Connor (1932-2020)* Donald O'Connor (1925–2003)* Sean O'Connor (born 1985)* Bill Oddie (born 1941)* Bob Odenkirk (born 1962)* Claudia O'Doherty (born 1983)* David O'Doherty (born 1975)* Mark O'Donnell (1954–2012)* Rosie O'Donnell (born 1962)* Steve O'Donnell (born 1954)* Michael O'Donoghue (1940–1994)* Chris O'Dowd (born 1979)* Nick Offerman (born 1970)* Paul O'Grady (1955-2023)* Ardal O'Hanlon (born 1965)* Catherine O'Hara (born 1954)* Jim O'Heir (born 1962)* John O'Hurley (born 1954)* Atsuko Okatsuka (born 1988)* Tricia O'Kelley (born 1968)* Earl Okin (born 1947)* Amy Okuda (born 1989)* John Oliver (born 1977)* Alberto Olmedo (1933–1988)* Ole Olsen (1892–1963)* Kaitlin Olson (born 1975)* Conner O'Malley (born 1986)* Mike O'Malley (born 1966)* Timothy Omundson (born 1969)* Patrice O'Neal (1969–2011)* Ed O'Neill (born 1946)* Steve Oram (born 1973)* Yvonne Orji (born 1983)* Zak Orth (born 1970)* Andrew Orvedahl (born 1976)* Barunka O'Shaughnessy* Andi Osho (born 1973)* Aida Osman (born 1997)* David Ossman (born 1936)* Dan Oster (born 1981)* Patton Oswalt (born 1969)* Cheri Oteri (born 1962)* Rick Overton (born 1954)* Bill Owen (1914–1999)* Gary Owen (born 1974)* Larry Owens* Gil Ozeri===P===* Jack Paar (1918–2004)* Frankie Pace* Celia Pacquola (born 1983)* Anthony Padilla (born 1987)* Monica Padman (born 1987)* Elliot Page (born 1987)* LaWanda Page (1920–2002)* Natalie Palamides (born 1990)* Ron Palillo (1949–2012)* Michael Palin (born 1943)* Adam Pally (born 1982)* Candy Palmater (1968–2021)* Maulik Pancholy (born 1974)* Franklin Pangborn (1889–1958)* John Pankow (born 1954)* Tom Papa (born 1968)* Yannis Pappas (born 1975)* John Paragon (1954–2021)* Zhubin Parang (born 1981)* Jimmy Pardo (born 1966)* Ron Pardo (born 1967)* Lennon Parham (born 1976)* Sandeep Parikh (born 1980)* Randall Park (born 1974)* Sydney Park (born 1997)* Nicole Parker (born 1978)* Pardis Parker* Paula Jai Parker (born 1969)* Sarah Jessica Parker (born 1965)* Trey Parker (born 1969)* Chris Parnell (born 1967)* Grace Parra (born 1984)* Rachel Parris (born 1984)* Andy Parsons (born 1967)* Jim Parsons (born 1973)* Karyn Parsons (born 1966)* Jean-Claude Pascal (1927-1992)* Sara Pascoe (born 1981)* Joe Pasquale (born 1961)* David Pasquesi (born 1960)* Bastian Pastewka (born 1972)* Kasha Patel (born 1991)* Nimesh Patel (born 1986)* Punam Patel (born 1993)* Ravi Patel (born 1978)* Edi Patterson (born 1972)* Pat Paulsen (1927–1997)* Rob Paulsen (born 1956)* David Paymer (born 1954)* Allen Payne (born 1968)* Christina Pazsitzky (born 1976)* Ray Peacock (born 1973)* Trevor Peacock (1931-2021)* Jack Pearl (1894-1982)* Minnie Pearl (1912–1996)* Zack Pearlman (born 1988)* Josh Peck (born 1986)* Artemis Pebdani (born 1977)* Ron Pederson (born 1978)* Nasim Pedrad (born 1981)* Jordan Peele (born 1979)* Simon Pegg (born 1970)* Paula Pell (born 1963)* Jessimae Peluso (born 1982)* Johnny Pemberton (born 1981)* Steve Pemberton (born 1967)* Kal Penn (born 1977)* Joe Penner (1904–1941)* Eddie Pepitone (born 1958)* Jack Pepper (1902-1979)* Joe Pera (born 1988/1989)* Kevin Pereira (born 1982)* Chelsea Peretti (born 1978)* Danielle Perez * Dewayne Perkins (born 1990)* Kathleen Rose Perkins (born 1974)* Sue Perkins (born 1969)* Rhea Perlman (born 1948)* Matthew Perry (1969-2023)* Tyler Perry (born 1969)* Jon Pertwee (1919–1996)* Tammy Pescatelli (born 1969)* Melissa Peterman (born 1971)* Russell Peters (born 1970)* Paul Petersen (born 1945)* Cassandra Peterson (born 1951)* Alexandra Petri (born 1988)* Dat Phan (born 1975)* Jay Pharoah (born 1987)* J.J. Philbin (born 1974)* Regis Philbin (1931-2020)* Busy Philipps (born 1979)* Emo Philips (born 1956)* Henry Phillips (born 1969)* Sally Phillips (born 1970)* Philomaine Nanema, aka Philo (born 1982)* Dannah Phirman (born 1975)* Andrew Phung (born 1984)* Bobby Pickett (1938-2007)* Chonda Pierce (born 1960)* David Hyde Pierce (born 1959)* Amy Pietz (born 1969)* Karl Pilkington (born 1972)* Daniella Pineda (born 1987)* John Pinette (1964–2014)* Ryan Pinkston (born 1988)* Danielle Pinnock (born 1988)* Joe Piscopo (born 1951)* ZaSu Pitts (1894–1963)* Jeremy Piven (born 1965)* Nigel Planer (born 1953)* Ben Platt (born 1993)* Aubrey Plaza (born 1984)* Amy Poehler (born 1971)* Greg Poehler (born 1974)* Kevin Pollak (born 1957)* Mike Pollock (born 1965)* Jorge Porcel (1936–2006)* Javier Portales (1937–2003)* Chris Porter (born 1979)* Don Porter (1912-1997)* Brian Posehn (born 1966)* Tom Poston (1921–2007)* Annie Potts (born 1952)* Paula Poundstone (born 1959)* Dan Povenmire (born 1963)* Esther Povitsky (born 1988)* Dante Powell (born 1987/1988)* Glen Powell (born 1988)* Navin Prabhakar* Chris Pratt (born 1979)* Guy Pratt (born 1962)* Kyla Pratt (born 1986)* Laura Prepon (born 1980)* Jaime Pressly (born 1977)* Amber Preston* Eric Price (born 1974)* Tom Price (born 1980)* Freddie Prinze (1954–1977)* Freddie Prinze Jr. (born 1976)* Kiri Pritchard Mclean (born 1986)* Lauren Pritchard (born 1977)* Michael Pritchard (born 1950)* Philip Proctor (born 1940)* Markus Maria Profitlich (born 1960)* Greg Proops (born 1959)* Mark Proksch (born 1978)* Paul Provenza (born 1957)* Kelly Pryce (born 1986/1987)* DJ Pryor (born 1988)* Richard Pryor (1940–2005)* Danny Pudi (born 1979)* Rolo Puente (1939–2011)* Lucy Punch (born 1977)* Steve Punt (born 1962)* Missi Pyle (born 1972)===Q===* Caroline Quentin (born 1960)* Adam Quesnell (born 1981/1982)* Apollo Quiboloy (born 1950)* Kate Quigley (born 1982)* Brian Quinn (born 1976)* Colin Quinn (born 1959)* Frankie Quiñones (born 1983)* Pauline Quirke (born 1959)===R===* Stefan Raab (born 1966)* Gilda Radner (1946–1989)* Josh Radnor (born 1974)* Kat Radley (born 1985)* Charlotte Rae (1926–2018)* Issa Rae (born 1985)* Rags Ragland (1905–1946)* Jeff Ragsdale* Randy Rainbow (born 1981)* Mary Lynn Rajskub (born 1971)* Sheryl Lee Ralph (born 1956)* Louis Ramey* Harold Ramis (1944–2014)* Rachel Ramras (born 1974)* Chris Ramsey (born 1986)* Franchesca Ramsey (born 1983)* Tony Randall (1920–2004)* Joe Randazzo (born 1978)* Frank Randle (1901–1957)* Romesh Ranganathan (born 1978)* Richard Rankin (born 1983)* Stephen Rannazzisi (born 1977)* Andrew Rannells (born 1978)* Michael Rapaport (born 1970)* June Diane Raphael (born 1980)* Jim Rash (born 1971)* Allison Raskin (born 1989)* Meaghan Rath (born 1986)* Connor Ratliff* John Ratzenberger (born 1947)* Melissa Rauch (born 1980)* Raven-Symoné (born 1985)* Donnell Rawlings (born 1968)* Adam Ray (born 1982)* Jonah Ray (born 1981)* Ted Ray (1905–1977)* Martha Raye (1916–1994)* Al Read (1909–1987)* Howard Read (born 1984)* Diona Reasonover (born 1992)* Spoken Reasons (born 1988)* Andreas Rebers (born 1958)* Chris Redd (born 1985)* Jasper Redd (born 1979)* Donna Reed (1921-1986)* Jon Reep (born 1972)* Vic Reeves (born 1959)* Brian Regan (born 1958)* Jason Reich* Sam Reich (born 1984)* Noah Reid (born 1987)* Tara Reid (born 1975)* Tim Reid (born 1944)* John C. Reilly (born 1965)* Carl Reiner (1922–2020)* Rob Reiner (born 1947)* Paul Reiser (born 1956)* Ivan Reitman (1946–2022)* Leah Remini (born 1970)* Roy Rene (1892–1954)* Adam Resnick* Retta (born 1970)* Paul Reubens (1952–2023)* Simon Rex (born 1974)* Alex Reymundo* Burt Reynolds (1936–2018)* John Reynolds (born 1991)* Rick Reynolds (born 1951)* Ryan Reynolds (born 1976)* Caroline Rhea (born 1964)* Erica Rhodes (born 1983)* Tom Rhodes (born 1967)* Alfonso Ribiero (born 1971)* Giovanni Ribisi (born 1974)* Alison Rich* Katie Rich* Simon Rich (born 1984)* Jeff Richards (born 1974)* Michael Richards (born 1949)* April Richardson (born 1979)* Jon Richardson (born 1982)* Matt Richardson (born 1991)* Miranda Richardson (born 1958)* Sam Richardson (born 1984)* Mathias Richling (born 1953)* Andy Richter (born 1966)* Laurence Rickard (born 1975)* Don Rickles (1926–2017)* Matt Rife (born 1995)* Daniel Rigby (born 1982)* Rob Riggle (born 1970)* Gina Riley (born 1961)* Jack Riley (1935–2016)* Kelly Ripa (born 1970)* Jason Ritter (born 1980)* John Ritter (1948–2003)* Tyler Ritter (born 1985)* Al Ritz (1901–1965)* Harry Ritz (1907–1986)* Jimmy Ritz (1904–1985)* Emilio Rivera (born 1961)* Joan Rivers (1933–2014)* Rowland Rivron (born 1958)* Steve Rizzo* Ted Robbins (born 1955)* Lyda Roberti (1906–1938)* Doris Roberts (1925–2016)* Ian Roberts (born 1965)* John Roberts (born 1971)* Jeanne Robertson (1943–2021)* Noah Robertson (born 1983)* Craig Robinson (born 1971)* Joe Robinson (born 1968)* Leonard Robinson* Phoebe Robinson (born 1984)* Tim Robinson (born 1981)* Linda Robson (born 1958)* Mo Rocca (born 1969)* Chris Rock (born 1965)* Tony Rock (born 1974)* Charles Rocket (1949–2005)* Glenn Rockowitz (born 1970)* Aida Rodriguez (born 1977)* Guillermo Rodriguez (born 1971)* Paul Rodriguez (born 1955)* Daniel Roebuck (born 1963)* Joe Rogan (born 1967)* Lauren Miller Rogen (born 1982)* Seth Rogen (born 1982)* Matt Rogers (born 1990)* Will Rogers (1879–1935)* Justin Roiland (born 1980)* Henry Rollins (born 1961)* Freddie Roman (1937–2022)* Rick Roman (1966–1992)* Larry Romano (born 1963)* Ray Romano (born 1957)* Michael Roof (1976–2009)* Mickey Rooney (1920–2014)* Stephen Root (born 1951)* George Roper (1934–2003)* Tony Rosato (1954–2017)* Patty Rosborough* Rose Marie (1923–2017)* Andrea Rosen (born 1974)* Michael Rosenbaum (born 1972)* Jeffrey Ross (born 1965)* Jonathan Ross (born 1960)* Lonny Ross (born 1978)* Tracee Ellis Ross (born 1972)* Steve Rossi (1932–2014)* Eli Roth (born 1972)* Barry Rothbart (born 1983)* Natasha Rothwell (born 1980)* Mitch Rouse (born 1964)* Patricia Routledge (born 1929)* Dan Rowan (1922–1987)* Patsy Rowlands (1931–2005)* Ben Roy (born 1979)* Alex Rubens* Michael Rubens* Alan Ruck (born 1956)* Paul Rudd (born 1969)* Rita Rudner (born 1953)* Jon Rudnitsky (born 1989)* Maya Rudolph (born 1972)* Amber Ruffin (born 1979)* Kevin Ruf (born 1961)* Sara Rue (born 1979)* Charlie Ruggles (1886–1970)* Chris Rush (1946–2018)* Lenny Rush (born 2009)* Willie Rushton (1937–1996)* Anna Russell (1911–2006)* Mark Russell (1932–2023)* Nipsey Russell (1918–2005)* Rosalind Russell (1907-1976)* Paul Rust (born 1981)* Nick Rutherford (born 1985)* Katherine Ryan (born 1983)* Tommy Ryman (born 1983)===S===* Daryl Sabara (born 1992)* Thomas Sadoski (born 1976)* Jerry Sadowitz (born 1961)* Bryan Safi* Katey Sagal (born 1954)* Bob Saget (1956–2022)* Tami Sagher* Mort Sahl (1927–2021)* Nichole Sakura (born 1989)* Rosa Salazar (born 1985)* Charles \"Chic\" Sale (1885–1936)* Soupy Sales (1926–2009)* Peter Sallis (1921–2017)* Tony Sam* Andy Samberg (born 1978)* Sugar Sammy (born 1976)* Angus Sampson (born 1978/1979)* Paul Sand (born 1932)* Adam Sandler (born 1966)* Isabel Sanford (1917-2004)* Andrew Santino (born 1983)* Carlos Santos (born 1986)* Nico Santos (born 1979)* Horatio Sanz (born 1969)* Herb Sargent (1923–2005)* Martin Sargent (born 1975)* Will Sasso (born 1975)* Drake Sather (1959–2004)* Rajiv Satyal (born 1976)* Jennifer Saunders (born 1958)* Andrea Savage (born 1973)* Ben Savage (born 1980)* Fred Savage (born 1976)* Alexei Sayle (born 1952)* Brendan Scannell (born 1990)* Kristen Schaal (born 1978)* Sara Schaefer (born 1978)* Akiva Schaffer (born 1977)* Jackie Schaffer* Jeff Schaffer (born 1970)* Lewis Schaffer (born 1957)* Tom Scharpling (born 1969)* Mary Scheer (born 1963)* Paul Scheer (born 1976)* Ronnie Schell (born 1931)* Gus Schilling (1908–1957)* Robert Schimmel (1950–2010)* Hayden Schlossberg (born 1978)* Art Paul Schlosser (born 1960)* Wilfried Schmickler (born 1954)* Harald Schmidt (born 1957)* Jana Schmieding* Ralf Schmitz (born 1974)* Danielle Schneider (born 1975)* Helge Schneider (born 1955)* Martin Schneider (born 1964)* Rob Schneider (born 1963)* Sarah Schneider (born 1983)* Stephen Schneider (born 1980)* Barbara Schöneberger (born 1974)* Avery Schreiber (1935–2002)* Paul Schrier (born 1970)* Atze Schröder (born 1965)* Olaf Schubert (born 1967)* Richard Schull (1929–1999)* Andrew Schulz (born 1983)* Amy Schumer (born 1981)* Michael Schur (born 1975)* Leon Schuster (born 1951)* Samba Schutte (born 1983)* Ben Schwartz (born 1981)* Jason Schwartzman (born 1980)* Esther Schweins (born 1970)* David Schwimmer (born 1966)* Peter Scolari (1955–2021)* Brian Scolaro (born 1973)* Adam Scott (born 1973)* Reid Scott (born 1977)* Tom Everett Scott (born 1970)* Seann William Scott (born 1976)* Rory Scovel (born 1980)* Amanda Seales (born 1981)* Kenny Sebastian (born 1990)* Harry Secombe (1921–2001)* Amy Sedaris (born 1961)* Rhea Seehorn (born 1972)* George Segal (1934–2021)* Jason Segel (born 1980)* Tom Segura (born 1979)* Streeter Seidell (born 1982)* Jerry Seinfeld (born 1954)* Peter Sellers (1925–1980)* Larry Semon (1889–1928)* Mack Sennett (1880–1960)* Rachel Sennott (born 1995)* Peter Serafinowicz (born 1972)* Josh Server (born 1979)* Joshua Seth (born 1970)* Glenn Shadix (1952–2010)* Ross Shafer (born 1954)* Paul Shaffer (born 1949)* Ari Shaffir (born 1974)* Tony Shalhoub (born 1953)* Garry Shandling (1949–2016)* Paul Shane (1940-2013)* Molly Shannon (born 1964)* Kapil Sharma (born 1981)* William Shatner (born 1931)* Alia Shawkat (born 1989)* Dick Shawn (1923–1987)* Wallace Shawn (born 1943)* Lin Shaye (born 1943)* Brendan Schaub (born 1983)* Harry Shearer (born 1943)* Reece Shearsmith (born 1969)* Charlie Sheen (born 1965)* Derek Sheen (born 1970/1971)* David Sheffield (born 1948)* Angela V. Shelton (born 1970)* Dax Shepard (born 1975)* Sherri Shepherd (born 1967)* Waen Shepherd (born 1971)* Rondell Sheridan (born 1958)* Allan Sherman (1924–1973)* Sarah Sherman (born 1993)* Brad Sherwood (born 1964)* Tom Shillue (born 1966)* Ken Shimura (1950–2020)* Kevin Shinick (born 1969)* Iliza Shlesinger (born 1983)* Craig Shoemaker (born 1962)* Pauly Shore (born 1968)* Sammy Shore (1928–2019)* Martin Short (born 1950)* Pat Shortt (born 1967)* Michael Showalter (born 1970)* Wil Shriner (born 1953)* Jimmy Shubert* Rosie Shuster (born 1950)* Ritch Shydner (born 1952)* Ali Siddiq (born 1973/1974)* George Sidney (1876-1945)* Denny Siegel * Darien Sills-Evans (born 1974)* Laura Silverman (born 1966)* Sarah Silverman (born 1970)* Max Silvestri (born 1983)* Phil Silvers (1911–1985)* Arthur Simeon (born 1974)* John Simmit (born 1963)* Sam Simmons (born 1977)* Hannah Simone (born 1980)* Timothy Simons (born 1978)* Jimmi Simpson (born 1975)* Joan Sims (1930–2001)* Sinbad (born 1956)* Akaash Singh (born 1984)* Lilly Singh (born 1988)* Hella von Sinnen (born 1959)* Tiya Sircar (born 1982)* Dave Sirus* Red Skelton (1913–1997)* Benito Skinner* Frank Skinner (born 1957)* Chuck Sklar* Jenny Slate (born 1982)* Tony Slattery (born 1959)* Jonathan Slavin (born 1969)* Bobby Slayton (born 1955)* Dulcé Sloan (born 1983)* Lindsay Sloane (born 1977)* Daniel Sloss (born 1990)* Brendon Small (born 1975)* Lucien \"Saluche\" Small (1948–2007)* Andy Smart (1959–2023)* Jean Smart (born 1951)* Robert Smigel (born 1960)* Rickey Smiley (born 1968)* Yakov Smirnoff (born 1951)* Arthur Smith (born 1954)* Brandon Mychal Smith (born 1989)* Brian Thomas Smith (born 1977)* DeAnne Smith (born 1979)* Joe Smith (1884–1981)* Kevin Smith (born 1970)* Kurtwood Smith (born 1943)* Linda Smith (1958–2006)* Margaret Smith* Will Smith (born 1968)* Will Smith (born 1971)* Yeardley Smith (born 1964)* JB Smoove (born 1965)* Cobie Smulders (born 1982)* Allisyn Snyder (born 1996)* Dana Snyder (born 1973)* Liza Snyder (born 1968)* Barry Sobel (born 1959)* Betsy Sodaro (born 1984)* Dan Soder (born 1983)* John Solomon (born 1970)* Laura Solon (born 1979)* Lion Solser (born 1877)* Kira Soltanovich (born 1973)* Suzanne Somers (1946–2023)* Rich Sommer (born 1978)* Sommore (born 1966)* Karan Soni (born 1989)* Ann Sothern (1909-2001)* Karla Souza (born 1985)* Kevin Spacey (born 1959)* David Spade (born 1964)* Hal Sparks (born 1969)* Ron Sparks (born 1977)* Aries Spears (born 1975)* Rachel Specter (born 1980)* Chris Spencer (born 1968)* Dave Spikey (born 1950)* Brent Spiner (born 1949)* Justin Spitzer* Thomas Spitzer (born 1988)* Emily Spivey (born 1971)* Brian Stack (born 1964)* Jessica St. Clair (born 1976)* Megan Stalter (born 1990)* John Stamos (born 1963)* Arnold Stang (1918–2009)* Doug Stanhope (born 1967)* Vivian Stanshall (1943–1995)* Martin Starr (born 1982)* Jen Statsky (born 1985)* Mark Steel (born 1960)* Steve Steen (born 1954)* Mary Steenburgen (born 1953)* Rob Stefaniuk (born 1971)* David Steinberg (born 1942)* Beth Stelling (born 1986)* Jason Stephens * Pamela Stephenson (born 1949)* Ford Sterling (1883–1939)* Mindy Sterling (born 1953)* Howard Stern (born 1954)* Steve-O (born 1974)* Michael Fenton Stevens (born 1958)* Brody Stevens (1970–2019)* Ray Stevens (born 1939)* French Stewart (born 1964)* Jon Stewart (born 1962)* Paul Stewart (1908–1986)* Ryan Stiles (born 1959)* Ben Stiller (born 1965)* Jerry Stiller (1927–2020)* Jeff Stilson (born 1959)* Fred Stoller (born 1958)* Nicholas Stoller (born 1976)* Matt Stone (born 1971)* Eric Stonestreet (born 1971)* Larry Storch (1923–2022)* Ryan Stout (born 1982)* Michael Strahan (born 1971)* Cordula Stratmann (born 1963)* Daren Streblow (born 1971)* Paul Strickland (born ?", ")* Cecily Strong (born 1984)* Rider Strong (born 1979)* Jud Strunk (1936–1981)* Moses Storm (born 1990)* Tom Stourton (born 1987)* James Patrick Stuart (born 1968)* Geoff Stults (born 1977)* Jason Sudeikis (born 1975)* Chris Sugden (born 1952)* Alec Sulkin (born 1973)* Nicole Sullivan (born 1970)* Slim Summerville (1892–1946)* Tika Sumpter (born 1980)* Ethan Suplee (born 1976)* Kevin Sussman (born 1970)* Mena Suvari (born 1979)* Nick Swardson (born 1976)* John Swartzwelder (born 1949)* Jim Sweeney (born 1955)* Julia Sweeney (born 1959)* Steve Sweeney (born 1949)* Terry Sweeney (born 1950)* C. C. Swiney (born 1981)* Eric Sykes (1923–2012)* Wanda Sykes (born 1964)* Cynthia Szigeti (1949–2016)* Magda Szubanski (born 1961)===T===* Jorma Taccone (born 1977)* Rich Talarico (born 1973)* Jill Talley (born 1962)* Chris Tallman (born 1970)* Kerry Talmage (1963–2004)* Kapil Talwalkar (born 1993)* Danny Tamberelli (born 1982)* Jeffrey Tambor (born 1944)* Carl Tart (born 1989)* Drew Tarver (born 1986)* Emily Tarver (born 1982)* Masashi Tashiro (born 1956)* Catherine Tate (born 1969)* Jacques Tati (1907–1982)* Jimmy Tatro (born 1992)* Jim Tavaré (born 1963)* Christine Taylor (born 1971)* Clarice Taylor (1917–2011)* Ellie Taylor (born 1983)* Johnny Taylor Jr.* Maddie Taylor (born 1966)* Paul Taylor (born 1986)* Rip Taylor (1931–2019)* Tariq Teddy* Teller (born 1948)* Miles Teller (born 1987)* Judy Tenuta (1949–2022)* Maria Thayer (born 1975)* Robin Thede (born 1979)* Derek Theler (born 1986)* Justin Theroux (born 1971)* Alan Thicke (1947–2016)* Terry-Thomas (1911–1990)* Craig Thomas* Danny Thomas (1914–1991)* Dave Thomas (born 1949)* Eddie Kaye Thomas (born 1980)* Jay Thomas (1948–2017)* Joe Thomas (born 1983)* Josh Thomas (born 1987)* Mark Thomas (born 1967)* Marlo Thomas (born 1937)* Michelle Thomas (1968–1998)* Vinny Thomas (born 1997)* Whitmer Thomas (born 1989)* Tim Thomerson (born 1946)* Greg Thomey (born 1961)* Bobb'e J. Thompson (born 1996)* Dave Thompson (born 1959)* Emma Thompson (born 1959)* Josh Robert Thompson (born 1975)* Kenan Thompson (born 1978)* Lea Thompson (born 1961)* Scott Thompson (born 1959)* Siobhan Thompson (born 1984)* Nick Thune (born 1979)* Baratunde Thurston (born 1977)* Sarah Thyre (born 1968)* Kai Tier* Tommy Tiernan (born 1969)* Christopher Titus (born 1964)* Mukesh Tiwari (born 1969)* Stephen Tobolowsky (born 1951)* Thelma Todd (1905–1935)* Sandi Toksvig (born 1958)* Judy Toll (1958–2002)* Allison Tolman (born 1981)* Lily Tomlin (born 1939)* David Tomlinson (1917-2000)* Taylor Tomlinson (born 1993)* Paul F. Tompkins (born 1968)* TomSka (born 1990)* Paul Tonkinson (born 1969)* Barry Took (1928–2002)* Shayne Topp (born 1991)* Rip Torn (1931–2019)* Nate Torrence (born 1977)* Julio Torres (born 1987)* Liz Torres (born 1947)* Guy Torry (born 1969)* Joe Torry (born 1965)* Daniel Tosh (born 1975)* Robert Townsend (born 1957)* Jerry Trainor (born 1977)* Rosie Tran (born 1984)* Tien Tran (born 1987)* Angela Trimbur (born 1981)* Tommy Trinder (1909–1989)* Chloe Troast (born 1997)* Duncan Trussell (born 1974)* Irene Tu (born 1992)* Bryan Tucker* Chris Tucker (born 1971)* Alan Tudyk (born 1971)* Jane Turner (born 1960)* Ben Turpin (1869–1940)* Aisha Tyler (born 1970)===U===* Alanna Ubach (born 1975)* Bob Uecker (born 1935)* Tracey Ullman (born 1959)* Sheryl Underwood (born 1963)* Brian Unger (born 1965)* Gabrielle Union (born 1972)* Stanley Unwin (1911–2002)* James Urbaniak (born 1963)* Michael Urie (born 1980)===V===* John Valby, aka Dr.", "Dirty (born 1944)* Wilmer Valderrama (born 1980)* Ramón Valdés (1923–1988)* Gary Valentine (born 1961)* Billy Van (1934–2003)* Dick Van Dyke (born 1925)* Jerry Van Dyke (1931–2018)* Dick Van Patten (1928–2015)* Danitra Vance (1954–1994)* Nia Vardalos (born 1962)* Janet Varney (born 1976)* Jim Varney (1949–2000)* Baron Vaughn (born 1980)* Vince Vaughn (born 1970)* Milana Vayntrub (born 1987)* Radhika Vaz (born 1973)* Jennifer Veal (born 1991)* Johnny Vegas (born 1970)* Vinny Vella (1947-2019)* Prashanth Venkataramanujam (born 1987)* Milo Ventimiglia (born 1977)* Sofia Vergara (born 1972)* Andrée Vermeulen (born 1982)* Jackie Vernon (1924–1987)* Wally Vernon (1904–1970)* Eva Victor* John Viener (born 1972)* Gillian Vigman (born 1972)* Kulap Vilaysack (born 1980)* Carlos Villagrán (born 1942)* Melissa Villaseñor (born 1987)* Tim Vine (born 1967)* Geraldine Viswanathan (born 1995)* Jon Vitti (born 1960)* Édgar Vivar (born 1944)* Paul C. Vogt (born 1964)* Theo Von (born 1980)* Daniel von Bargen (1950–2015)* Rich Vos (born 1957)* Sal Vulcano (born 1976)===W===* Otto Waalkes (born 1948)* Mark Wahlberg (born 1971)* David Wain (born 1969)* Lena Waithe (born 1984)* Taika Waititi (born 1975)* Eliot Wald (1946–2003)* Gary Waldhorn (1943-2022)* Christopher Walken (born 1943)* Benjamin Walker (born 1982)* Devon Walker (born 1991)* Doug Walker (born 1981)* Holly Walker (born 1967)* Jimmie Walker (born 1947)* Nancy Walker (1922-1992)* Roy Walker (born 1940)* Max Wall (1908–1990)* Danny Wallace (born 1976)* George Wallace (1895–1960)* George Wallace Jnr (1918–1968)* George Wallace (born 1952)* Linda Wallem (born 1961)* Phoebe Waller-Bridge (born 1985)* David Walliams (born 1971)* Ruth Wallis (1920–2007)* Greg Walloch (born 1970)* Bradley Walsh (born 1960)* Brendon Walsh (born 1978)* Holly Walsh (born 1980)* Kate Walsh (born 1967)* Mary Walsh (born 1952)* Matt Walsh (born 1964)* Ray Walston (1914-2001)* Jessica Walter (1941–2021)* Lisa Ann Walter (born 1963)* Julie Walters (born 1950)* David Walton (born 1978)* Christoph Waltz (born 1956)* Sheng Wang (born 1980)* Keith Wann (born 1969)* Patrick Warburton (born 1964)* Mike Ward (born 1973)* Brandon Wardell (born 1992)* Eric Wareheim (born 1976)* Marsha Warfield (born 1954)* Malcolm-Jamal Warner (born 1970)* Mike Warnke (born 1946)* Rusty Warren (1930–2021)* Derek Waters (born 1979)* Michaela Watkins (born 1971)* Reggie Watts (born 1972)* Ruby Wax (born 1953)* Damon Wayans (born 1960)* Damon Wayans Jr. (born 1982)* Keenen Ivory Wayans (born 1958)* Kim Wayans (born 1961)* Marlon Wayans (born 1972)* Shawn Wayans (born 1971)* Kountry Wayne (born 1987)* Robert Webb (born 1972)* Steven Weber (born 1961)* Fred Wedlock (1942-2010)* Lauren Weedman (born 1969)* Ed Weeks (born 1980)* Henning Wehn (born 1974)* Brent Weinbach* Stephnie Weir (born 1967)* Oliver Welke (born 1966)* Danny Wells (1941-2013)* Noël Wells (born 1986)* George Wendt (born 1948)* Ali Wentworth (born 1965)* Amber Stevens West (born 1986)* Billy West (born 1952)* Lindy West (born 1982)* Alice Wetterlund (born 1981)* Wil Wheaton (born 1972)* Brooks Wheelan (born 1986)* Bert Wheeler (1895–1968)* Jill Whelan (born 1966)* Betty White (1922–2021)* Ellie White (born 1989)* Jaleel White (born 1976)* Mike White (born 1970)* Ron White (born 1956)* Slappy White (1921–1995)* Jack Whitehall (born 1988)* Jason John Whitehead* Paul Whitehouse (born 1958)* Bradley Whitford (born 1959)* Kym Whitley (born 1961)* Mae Whitman (born 1988)* Josh Widdicombe (born 1983)* Nick Wiger (born 1980)* Tracey Wigfield (born 1983)* Kristen Wiig (born 1973)* Brian Wilde (1927–2008)* Stefanie Wilder-Taylor* Fred Willard (1933–2020)* Ben Willbond (born 1973)* Allison Williams (born 1988)* Anson Williams (born 1949)* Ashley Williams (born 1978)* Barney Williams (1824–1876)* Bert Williams (1874–1922)* Brad Williams (born 1984)* Charlie Williams (1927–2006)* Chris Williams (born 1967)* Cindy Williams (1947–2023)* Gary Anthony Williams (born 1966)* Harland Williams (born 1962)* Jessica Williams (born 1986)* Katt Williams (born 1973)* Kenneth Williams (1926–1988)* Mason Williams (born 1938)* Robin Williams (1951–2014)* Tyler James Williams (born 1992)* Victor Williams (born 1970)* Wendy Williams (born 1964)* Dave Williamson* Taylor Williamson* Cardis Cardell Willis (1937–2007)* Dave Willis (born 1970)* Dave Willis (1895–1973)* Denny Willis (1920–1995)* Justin Willman (born 1980)* Emma Willmann (born 1985)* Holly Willoughby (born 1981)* Larry Wilmore (born 1961)* Cal Wilson (1970–2023)* Casey Wilson (born 1980)* Debra Wilson (born 1962)* Demond Wilson (born 1946)* Flip Wilson (1933–1998)* Luke Wilson (born 1971)* Owen Wilson (born 1968)* Rainn Wilson (born 1966)* Rebel Wilson (born 1980)* Reno Wilson (born 1969)* Thomas F. Wilson (born 1959)* Bob Wiltfong (born 1969)* April Winchell (born 1962)* Henry Winkler (born 1945)* Lizz Winstead (born 1961)* Jonathan Winters (1925–2013)* Norman Wisdom (1915–2010)* Chris Witaske (born 1983)* Brenda Withers* Harris Wittels (1984–2015)* Fred Wolf (born 1964)* Michelle Wolf (born 1985)* Dennis Wolfberg (1946–1994)* Jason Woliner (born 1980)* Ali Wong (born 1982)* Kristina Wong (born 1978)* Roy Wood Jr. (born 1978)* Victoria Wood (1953–2016)* Danny Woodburn (born 1964)* Kim Woodburn (born 1942)* Zach Woods (born 1984)* Glenn Wool (born 1974)* Sheb Wooley (1921-2003)* Robert Woolsey (1888–1938)* Harry Worth (1917–1989)* Mike Wozniak (born 1979)* Edgar Wright (born 1974)* Steven Wright (born 1955)* Sabrina Wu (born 1998)* Robert Wuhl (born 1951)* Ed Wynn (1886–1966)===X===* Swami X (1925–2015)===Y===* Rajpal Yadav (born 1971)* Marc Yaffee (born 1961)* Kaya Yanar (born 1973)* Alan Yang (born 1983)* Bowen Yang (born 1990)* Eugene Lee Yang (born 1986)* Jenny Yang* Jimmy O. Yang (born 1987)* \"Weird Al\" Yankovic (born 1959)* Cedric Yarbrough (born 1973)* Mike Yard* Mike Yarwood (1941–2023)* Gina Yashere (born 1974)* Lucky Yates (born 1967)* Dustin Ybarra (born 1989)* Steven Yeun (born 1983)* Charlyne Yi (born 1986)* Cem Yılmaz (born 1973)* Celeste Yim (born 1996)* Aaron Yonda (born 1973)* Dwight York* Heléne Yorke (born 1985)* Alan Young (1919–2016)* Bill Young (died 2014)* Parker Young (born 1988)* Rick Younger (born 1969)* Henny Youngman (1906–1998)* Jaboukie Young-White (born 1994)* Hampton Yount (born 1984)* Bassem Youssef (born 1974)* Ramy Youssef (born 1991)* Joe Yule (1892–1950)* Imran Yusuf (born 1979)===Z===* Tincho Zabala (1923–2001)* Hollywood Zakoshisyoh (born 1974)* Andy Zaltzman (born 1974)* Sasheer Zamata (born 1986)* Katya Zamolodchikova* Alex Zane (born 1979)* Bob Zany (born 1961)* Steve Zahn (born 1967)* Steve Zaragoza (born 1982)* Vitaly Zdorovetskiy (born 1992)* Volodymyr Zelenskyy (born 1978)* Henry Zebrowski (born 1984)* David Zed* Mather Zickel (born 1970)* Dolph Ziggler (born 1980)* Jenny Zigrino (born 1987)* Jason Zimbler (born 1977)* Steve Zissis (born 1975)* Alan Zweibel (born 1950)" ], [ "Comedy groups", "* Ant & Dec* Armstrong and Miller* Abbott and Costello* Barats and Bereta* Beyond the Fringe* Bob and Ray* Bonzo Dog Doo-Dah Band* BriTANicK* Broken Lizard* Brown and Carney* Burns and Allen* The Chaser* Les Charlots* Cheech and Chong* Clark and McCullough* The Comedy Store Players* The Comic Strip* Dalton Trumbo's Reluctant Cabaret* The Firesign Theatre* Flight of the Conchords* Frangela* The Frat Pack* French and Saunders* Garfunkel and Oates* God's Pottery* The Goons* The Grumbleweeds* Hale and Pace* Hamish and Andy* Hard 'n Phirm* Homer and Jethro* Key and Peele* The Kids in the Hall* The Kipper Kids* Kreisiraadio from Estonia* Lano and Woodley* Laurel and Hardy* The League of Gentlemen* Little Britain* The Little Rascals* The Lonely Island* Les Luthiers* The Lucas Brothers* Marijuana Logues* Martin and Lewis* Marx Brothers* McKenzie Brothers* The Mighty Boosh* The Minnesota Wrecking Crew* Mitchell and Webb* Monty Python* Morecambe and Wise* Not Ready for Prime-Time Players (''Saturday Night Live'')* Paul and Storm* Penn & Teller* Pete and Dud* Phil Lord and Christopher Miller* Please Don't Destroy* Punt and Dennis* Reeves and Mortimer* The Ritz Brothers* Rowan and Martin* Royal Canadian Air Farce* Scotland the What?", "* Sklar Brothers* Smith and Dale* Smosh* Smothers Brothers* Stella* Stiller and Meara* Studio C* Tenacious D* The Tenderloins* The Three Stooges* Tim and Eric* The Try Guys* The Umbilical Brothers* Upright Citizens Brigade* The Valleyfolk* Wayne and Shuster* Wheeler and Woolsey* The Whitest Kids U' Know" ], [ "Comedy writers", "''(sorted alphabetically by surname)''* Douglas Adams (1952–2011)* Fred Allen (1894–1956)* Woody Allen (born 1935)* Chesney and Wolfe* Roy Clarke (born 1930)* Dick Clement (born 1937)* David Croft (1922–2011)* Barry Cryer* Esmonde and Larbey* Galton and Simpson* W. S. Gilbert* Willis Hall* Antony Jay* Carla Lane* Ian La Frenais (born 1937)* Graham Linehan and Arthur Mathews* Jeremy Lloyd* David Nobbs* Simon Nye* Frank Muir* Denis Norden* S. J. Perelman* Jimmy Perry* David Renwick* Jack Rosenthal* David Sedaris* Gerardo Sofovich (1937–2015)* Hugo Sofovich (1939–2003)* Johnny Speight* John Sullivan* James Thurber* Peter Tinniswood* Zoë Tomalin* Keith Waterhouse" ], [ "See also", "'''Lists of comedians by nationality'''*List of Australian comedians*List of British comedians*List of Canadian comedians*List of Dutch comedians*List of Finnish comedians*List of German comedians*List of Indian comedians*List of Italian comedians*List of Japanese comedians*List of Mexican comedians*List of Norwegian comedians*List of Portuguese comedians*List of Puerto Rican comedians*List of United States stand-up comedians'''Other related lists'''*List of comedy films*List of deadpan comedians*List of humorists*List of musical comedians*List of New York Improv comedians*List of stand-up comedians" ] ]
wikipedia
[ [ "Compact space" ], [ "Introduction", " Per the compactness criteria for Euclidean space as stated in the Heine–Borel theorem, the interval is not compact because it is not bounded.", "The interval is not compact because it is not closed (but bounded).", "The interval is compact because it is both closed and bounded.In mathematics, specifically general topology, '''compactness''' is a property that seeks to generalize the notion of a closed and bounded subset of Euclidean space.", "The idea is that a compact space has no \"punctures\" or \"missing endpoints\", i.e., it includes all ''limiting values'' of points.", "For example, the open interval (0,1) would not be compact because it excludes the limiting values of 0 and 1, whereas the closed interval 0,1 would be compact.", "Similarly, the space of rational numbers is not compact, because it has infinitely many \"punctures\" corresponding to the irrational numbers, and the space of real numbers is not compact either, because it excludes the two limiting values and .", "However, the ''extended'' real number line ''would'' be compact, since it contains both infinities.", "There are many ways to make this heuristic notion precise.", "These ways usually agree in a metric space, but may not be equivalent in other topological spaces.One such generalization is that a topological space is ''sequentially'' compact if every infinite sequence of points sampled from the space has an infinite subsequence that converges to some point of the space.", "The Bolzano–Weierstrass theorem states that a subset of Euclidean space is compact in this sequential sense if and only if it is closed and bounded.", "Thus, if one chooses an infinite number of points in the closed unit interval , some of those points will get arbitrarily close to some real number in that space.", "For instance, some of the numbers in the sequence accumulate to 0 (while others accumulate to 1).", "Since neither 0 nor 1 are members of the open unit interval , those same sets of points would not accumulate to any point of it, so the open unit interval is not compact.", "Although subsets (subspaces) of Euclidean space can be compact, the entire space itself is not compact, since it is not bounded.", "For example, considering (the real number line), the sequence of points has no subsequence that converges to any real number.Compactness was formally introduced by Maurice Fréchet in 1906 to generalize the Bolzano–Weierstrass theorem from spaces of geometrical points to spaces of functions.", "The Arzelà–Ascoli theorem and the Peano existence theorem exemplify applications of this notion of compactness to classical analysis.", "Following its initial introduction, various equivalent notions of compactness, including sequential compactness and limit point compactness, were developed in general metric spaces.", "In general topological spaces, however, these notions of compactness are not necessarily equivalent.", "The most useful notion — and the standard definition of the unqualified term ''compactness'' — is phrased in terms of the existence of finite families of open sets that \"cover\" the space in the sense that each point of the space lies in some set contained in the family.", "This more subtle notion, introduced by Pavel Alexandrov and Pavel Urysohn in 1929, exhibits compact spaces as generalizations of finite sets.", "In spaces that are compact in this sense, it is often possible to patch together information that holds locally – that is, in a neighborhood of each point – into corresponding statements that hold throughout the space, and many theorems are of this character.The term '''compact set''' is sometimes used as a synonym for compact space, but also often refers to a compact subspace of a topological space." ], [ "Historical development", "In the 19th century, several disparate mathematical properties were understood that would later be seen as consequences of compactness.", "On the one hand, Bernard Bolzano (1817) had been aware that any bounded sequence of points (in the line or plane, for instance) has a subsequence that must eventually get arbitrarily close to some other point, called a limit point.", "Bolzano's proof relied on the method of bisection: the sequence was placed into an interval that was then divided into two equal parts, and a part containing infinitely many terms of the sequence was selected.", "The process could then be repeated by dividing the resulting smaller interval into smaller and smaller parts – until it closes down on the desired limit point.", "The full significance of Bolzano's theorem, and its method of proof, would not emerge until almost 50 years later when it was rediscovered by Karl Weierstrass.In the 1880s, it became clear that results similar to the Bolzano–Weierstrass theorem could be formulated for spaces of functions rather than just numbers or geometrical points.", "The idea of regarding functions as themselves points of a generalized space dates back to the investigations of Giulio Ascoli and Cesare Arzelà.", "The culmination of their investigations, the Arzelà–Ascoli theorem, was a generalization of the Bolzano–Weierstrass theorem to families of continuous functions, the precise conclusion of which was that it was possible to extract a uniformly convergent sequence of functions from a suitable family of functions.", "The uniform limit of this sequence then played precisely the same role as Bolzano's \"limit point\".", "Towards the beginning of the twentieth century, results similar to that of Arzelà and Ascoli began to accumulate in the area of integral equations, as investigated by David Hilbert and Erhard Schmidt.", "For a certain class of Green's functions coming from solutions of integral equations, Schmidt had shown that a property analogous to the Arzelà–Ascoli theorem held in the sense of mean convergence – or convergence in what would later be dubbed a Hilbert space.", "This ultimately led to the notion of a compact operator as an offshoot of the general notion of a compact space.", "It was Maurice Fréchet who, in 1906, had distilled the essence of the Bolzano–Weierstrass property and coined the term ''compactness'' to refer to this general phenomenon (he used the term already in his 1904 paper which led to the famous 1906 thesis).However, a different notion of compactness altogether had also slowly emerged at the end of the 19th century from the study of the continuum, which was seen as fundamental for the rigorous formulation of analysis.", "In 1870, Eduard Heine showed that a continuous function defined on a closed and bounded interval was in fact uniformly continuous.", "In the course of the proof, he made use of a lemma that from any countable cover of the interval by smaller open intervals, it was possible to select a finite number of these that also covered it.", "The significance of this lemma was recognized by Émile Borel (1895), and it was generalized to arbitrary collections of intervals by Pierre Cousin (1895) and Henri Lebesgue (1904).", "The Heine–Borel theorem, as the result is now known, is another special property possessed by closed and bounded sets of real numbers.This property was significant because it allowed for the passage from local information about a set (such as the continuity of a function) to global information about the set (such as the uniform continuity of a function).", "This sentiment was expressed by , who also exploited it in the development of the integral now bearing his name.", "Ultimately, the Russian school of point-set topology, under the direction of Pavel Alexandrov and Pavel Urysohn, formulated Heine–Borel compactness in a way that could be applied to the modern notion of a topological space.", "showed that the earlier version of compactness due to Fréchet, now called (relative) sequential compactness, under appropriate conditions followed from the version of compactness that was formulated in terms of the existence of finite subcovers.", "It was this notion of compactness that became the dominant one, because it was not only a stronger property, but it could be formulated in a more general setting with a minimum of additional technical machinery, as it relied only on the structure of the open sets in a space." ], [ "Basic examples", "Any finite space is compact; a finite subcover can be obtained by selecting, for each point, an open set containing it.", "A nontrivial example of a compact space is the (closed) unit interval of real numbers.", "If one chooses an infinite number of distinct points in the unit interval, then there must be some accumulation point among these points in that interval.", "For instance, the odd-numbered terms of the sequence get arbitrarily close to 0, while the even-numbered ones get arbitrarily close to 1.The given example sequence shows the importance of including the boundary points of the interval, since the limit points must be in the space itself — an open (or half-open) interval of the real numbers is not compact.", "It is also crucial that the interval be bounded, since in the interval , one could choose the sequence of points , of which no sub-sequence ultimately gets arbitrarily close to any given real number.In two dimensions, closed disks are compact since for any infinite number of points sampled from a disk, some subset of those points must get arbitrarily close either to a point within the disc, or to a point on the boundary.", "However, an open disk is not compact, because a sequence of points can tend to the boundary – without getting arbitrarily close to any point in the interior.", "Likewise, spheres are compact, but a sphere missing a point is not since a sequence of points can still tend to the missing point, thereby not getting arbitrarily close to any point ''within'' the space.", "Lines and planes are not compact, since one can take a set of equally-spaced points in any given direction without approaching any point." ], [ "Definitions", "Various definitions of compactness may apply, depending on the level of generality.", "A subset of Euclidean space in particular is called compact if it is closed and bounded.", "This implies, by the Bolzano–Weierstrass theorem, that any infinite sequence from the set has a subsequence that converges to a point in the set.", "Various equivalent notions of compactness, such as sequential compactness and limit point compactness, can be developed in general metric spaces.In contrast, the different notions of compactness are not equivalent in general topological spaces, and the most useful notion of compactness – originally called ''bicompactness'' – is defined using covers consisting of open sets (see ''Open cover definition'' below).", "That this form of compactness holds for closed and bounded subsets of Euclidean space is known as the Heine–Borel theorem.", "Compactness, when defined in this manner, often allows one to take information that is known locally – in a neighbourhood of each point of the space – and to extend it to information that holds globally throughout the space.", "An example of this phenomenon is Dirichlet's theorem, to which it was originally applied by Heine, that a continuous function on a compact interval is uniformly continuous; here, continuity is a local property of the function, and uniform continuity the corresponding global property.===Open cover definition===Formally, a topological space is called ''compact'' if every open cover of has a finite subcover.", "That is, is compact if for every collection of open subsets of such thatthere is a '''finite''' subcollection ⊆ such thatSome branches of mathematics such as algebraic geometry, typically influenced by the French school of Bourbaki, use the term ''quasi-compact'' for the general notion, and reserve the term ''compact'' for topological spaces that are both Hausdorff and ''quasi-compact''.", "A compact set is sometimes referred to as a ''compactum'', plural ''compacta''.=== Compactness of subsets ===A subset of a topological space is said to be compact if it is compact as a subspace (in the subspace topology).", "That is, is compact if for every arbitrary collection of open subsets of such thatthere is a '''finite''' subcollection ⊆ such thatCompactness is a topological property.", "That is, if , with subset equipped with the subspace topology, then is compact in if and only if is compact in .=== Characterization ===If is a topological space then the following are equivalent:# is compact; i.e., every open cover of has a finite subcover.# has a sub-base such that every cover of the space, by members of the sub-base, has a finite subcover (Alexander's sub-base theorem).# is Lindelöf and countably compact.# Any collection of closed subsets of with the finite intersection property has nonempty intersection.# Every net on has a convergent subnet (see the article on nets for a proof).# Every filter on has a convergent refinement.# Every net on has a cluster point.# Every filter on has a cluster point.# Every ultrafilter on converges to at least one point.# Every infinite subset of has a complete accumulation point.# For every topological space , the projection is a closed mapping (see proper map).Bourbaki defines a compact space (quasi-compact space) as a topological space where each filter has a cluster point (i.e., 8.in the above).", "==== Euclidean space ====For any subset of Euclidean space, is compact if and only if it is closed and bounded; this is the Heine–Borel theorem.As a Euclidean space is a metric space, the conditions in the next subsection also apply to all of its subsets.", "Of all of the equivalent conditions, it is in practice easiest to verify that a subset is closed and bounded, for example, for a closed interval or closed -ball.==== Metric spaces ====For any metric space , the following are equivalent (assuming countable choice):# is compact.# is complete and totally bounded (this is also equivalent to compactness for uniform spaces).# is sequentially compact; that is, every sequence in has a convergent subsequence whose limit is in (this is also equivalent to compactness for first-countable uniform spaces).# is limit point compact (also called weakly countably compact); that is, every infinite subset of has at least one limit point in .# is countably compact; that is, every countable open cover of has a finite subcover.# is an image of a continuous function from the Cantor set.# Every decreasing nested sequence of nonempty closed subsets in has a nonempty intersection.# Every increasing nested sequence of proper open subsets in fails to cover .A compact metric space also satisfies the following properties:# Lebesgue's number lemma: For every open cover of , there exists a number such that every subset of of diameter 1 ⊇ 2 ⊇ ... in has a nonempty intersection.# Every increasing nested sequence of proper open subsets 1 ⊆ 2 ⊆ ... in fails to cover .==== Characterization by continuous functions ====Let be a topological space and the ring of real continuous functions on .", "For each , the evaluation map given by is a ring homomorphism.", "The kernel of is a maximal ideal, since the residue field is the field of real numbers, by the first isomorphism theorem.", "A topological space is pseudocompact if and only if every maximal ideal in has residue field the real numbers.", "For completely regular spaces, this is equivalent to every maximal ideal being the kernel of an evaluation homomorphism.", "There are pseudocompact spaces that are not compact, though.In general, for non-pseudocompact spaces there are always maximal ideals in such that the residue field is a (non-Archimedean) hyperreal field.", "The framework of non-standard analysis allows for the following alternative characterization of compactness: a topological space is compact if and only if every point of the natural extension is infinitely close to a point of (more precisely, is contained in the monad of ).==== Hyperreal definition ====A space is compact if its hyperreal extension (constructed, for example, by the ultrapower construction) has the property that every point of is infinitely close to some point of .", "For example, an open real interval is not compact because its hyperreal extension contains infinitesimals, which are infinitely close to 0, which is not a point of ." ], [ "Sufficient conditions", "* A closed subset of a compact space is compact.", "* A finite union of compact sets is compact.", "* A continuous image of a compact space is compact.", "* The intersection of any non-empty collection of compact subsets of a Hausdorff space is compact (and closed);** If is not Hausdorff then the intersection of two compact subsets may fail to be compact (see footnote for example).", "* The product of any collection of compact spaces is compact.", "(This is Tychonoff's theorem, which is equivalent to the axiom of choice.", ")* In a metrizable space, a subset is compact if and only if it is sequentially compact (assuming countable choice)* A finite set endowed with any topology is compact." ], [ "Properties of compact spaces", "* A compact subset of a Hausdorff space is closed.", "** If is not Hausdorff then a compact subset of may fail to be a closed subset of (see footnote for example).", "** If is not Hausdorff then the closure of a compact set may fail to be compact (see footnote for example).", "* In any topological vector space (TVS), a compact subset is complete.", "However, every non-Hausdorff TVS contains compact (and thus complete) subsets that are ''not'' closed.", "* If and are disjoint compact subsets of a Hausdorff space , then there exist disjoint open sets and in such that and .", "* A continuous bijection from a compact space into a Hausdorff space is a homeomorphism.", "* A compact Hausdorff space is normal and regular.", "* If a space is compact and Hausdorff, then no finer topology on is compact and no coarser topology on is Hausdorff.", "* If a subset of a metric space is compact then it is -bounded.=== Functions and compact spaces ===Since a continuous image of a compact space is compact, the extreme value theorem holds for such spaces: a continuous real-valued function on a nonempty compact space is bounded above and attains its supremum.", "(Slightly more generally, this is true for an upper semicontinuous function.)", "As a sort of converse to the above statements, the pre-image of a compact space under a proper map is compact.=== Compactifications ===Every topological space is an open dense subspace of a compact space having at most one point more than , by the Alexandroff one-point compactification.", "By the same construction, every locally compact Hausdorff space is an open dense subspace of a compact Hausdorff space having at most one point more than .=== Ordered compact spaces ===A nonempty compact subset of the real numbers has a greatest element and a least element.Let be a simply ordered set endowed with the order topology.", "Then is compact if and only if is a complete lattice (i.e.", "all subsets have suprema and infima)." ], [ "Examples", "* Any finite topological space, including the empty set, is compact.", "More generally, any space with a finite topology (only finitely many open sets) is compact; this includes in particular the trivial topology.", "* Any space carrying the cofinite topology is compact.", "* Any locally compact Hausdorff space can be turned into a compact space by adding a single point to it, by means of Alexandroff one-point compactification.", "The one-point compactification of is homeomorphic to the circle ; the one-point compactification of is homeomorphic to the sphere .", "Using the one-point compactification, one can also easily construct compact spaces which are not Hausdorff, by starting with a non-Hausdorff space.", "* The right order topology or left order topology on any bounded totally ordered set is compact.", "In particular, Sierpiński space is compact.", "* No discrete space with an infinite number of points is compact.", "The collection of all singletons of the space is an open cover which admits no finite subcover.", "Finite discrete spaces are compact.", "* In carrying the lower limit topology, no uncountable set is compact.", "* In the cocountable topology on an uncountable set, no infinite set is compact.", "Like the previous example, the space as a whole is not locally compact but is still Lindelöf.", "* The closed unit interval is compact.", "This follows from the Heine–Borel theorem.", "The open interval is not compact: the open cover for does not have a finite subcover.", "Similarly, the set of ''rational numbers'' in the closed interval is not compact: the sets of rational numbers in the intervals cover all the rationals in 0, 1 for but this cover does not have a finite subcover.", "Here, the sets are open in the subspace topology even though they are not open as subsets of .", "* The set of all real numbers is not compact as there is a cover of open intervals that does not have a finite subcover.", "For example, intervals , where takes all integer values in , cover but there is no finite subcover.", "* On the other hand, the extended real number line carrying the analogous topology ''is'' compact; note that the cover described above would never reach the points at infinity and thus would ''not'' cover the extended real line.", "In fact, the set has the homeomorphism to −1, 1 of mapping each infinity to its corresponding unit and every real number to its sign multiplied by the unique number in the positive part of interval that results in its absolute value when divided by one minus itself, and since homeomorphisms preserve covers, the Heine-Borel property can be inferred.", "* For every natural number , the -sphere is compact.", "Again from the Heine–Borel theorem, the closed unit ball of any finite-dimensional normed vector space is compact.", "This is not true for infinite dimensions; in fact, a normed vector space is finite-dimensional if and only if its closed unit ball is compact.", "* On the other hand, the closed unit ball of the dual of a normed space is compact for the weak-* topology.", "(Alaoglu's theorem)* The Cantor set is compact.", "In fact, every compact metric space is a continuous image of the Cantor set.", "* Consider the set of all functions from the real number line to the closed unit interval, and define a topology on so that a sequence in converges towards if and only if converges towards for all real numbers .", "There is only one such topology; it is called the topology of pointwise convergence or the product topology.", "Then is a compact topological space; this follows from the Tychonoff theorem.", "* A subset of the Banach space of real-valued continuous functions on a compact Hausdorff space is relatively compact if and only if it is equicontinuous and pointwise bounded (Arzelà–Ascoli theorem).", "* Consider the set of all functions satisfying the Lipschitz condition for all .", "Consider on the metric induced by the uniform distance Then by the Arzelà–Ascoli theorem the space is compact.", "* The spectrum of any bounded linear operator on a Banach space is a nonempty compact subset of the complex numbers .", "Conversely, any compact subset of arises in this manner, as the spectrum of some bounded linear operator.", "For instance, a diagonal operator on the Hilbert space may have any compact nonempty subset of as spectrum.", "* The space of Borel probability measures on a compact Hausdorff space is compact for the vague topology, by the Alaoglu theorem.", "* A collection of probability measures on the Borel sets of Euclidean space is called ''tight'' if, for any positive epsilon, there exists a compact subset containing all but at most epsilon of the mass of each of the measures.", "Helly's theorem then asserts that a collection of probability measures is relatively compact for the vague topology if and only if it is tight.=== Algebraic examples ===* Topological groups such as an orthogonal group are compact, while groups such as a general linear group are not.", "* Since the -adic integers are homeomorphic to the Cantor set, they form a compact set.", "* Any global field ''K'' is a discrete additive subgroup of its adele ring, and the quotient space is compact.", "This was used in John Tate's thesis to allow harmonic analysis to be used in number theory.", "* The spectrum of any commutative ring with the Zariski topology (that is, the set of all prime ideals) is compact, but never Hausdorff (except in trivial cases).", "In algebraic geometry, such topological spaces are examples of quasi-compact schemes, \"quasi\" referring to the non-Hausdorff nature of the topology.", "* The spectrum of a Boolean algebra is compact, a fact which is part of the Stone representation theorem.", "Stone spaces, compact totally disconnected Hausdorff spaces, form the abstract framework in which these spectra are studied.", "Such spaces are also useful in the study of profinite groups.", "* The structure space of a commutative unital Banach algebra is a compact Hausdorff space.", "* The Hilbert cube is compact, again a consequence of Tychonoff's theorem.", "* A profinite group (e.g.", "Galois group) is compact." ], [ "See also", "* Compactly generated space* Compactness theorem* Eberlein compactum* Exhaustion by compact sets* Lindelöf space* Metacompact space* Noetherian topological space* Orthocompact space* Paracompact space* Quasi-compact morphism* Precompact set - also called ''totally bounded''* Relatively compact subspace* Totally bounded" ], [ "Notes" ], [ "References" ], [ "Bibliography", "* *.*.", "* (''Purely analytic proof of the theorem that between any two values which give results of opposite sign, there lies at least one real root of the equation'').", "**** * * * *** ** * * * .", "* *" ], [ "External links", "* ----" ] ]
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[ [ "Clodius" ], [ "Introduction", "Denarius issued for the anti-Neronian rebel Clodius Macer in 68 AD'''Clodius''' is an alternate form of the Roman ''nomen'' Claudius, a patrician ''gens'' that was traditionally regarded as Sabine in origin.", "The alternation of ''o'' and ''au'' is characteristic of the Sabine dialect.", "The feminine form is '''Clodia'''." ], [ "Republican era", "===Publius Clodius Pulcher===During the Late Republic, the spelling ''Clodius'' is most prominently associated with Publius Clodius Pulcher, a popularis politician who gave up his patrician status through an order in order to qualify for the office of tribune of the ''plebs''.", "Clodius positioned himself as a champion of the urban ''plebs'', supporting free grain for the poor and the right of association in guilds (''collegia''); because of this individual's ideology, ''Clodius'' has often been taken as a more \"plebeian\" spelling and a gesture of political solidarity.", "Clodius's two elder brothers, the Appius Claudius Pulcher who was consul in 54 BC and the C. Claudius Pulcher who was praetor in 56 BC, conducted more conventional political careers and are referred to in contemporary sources with the traditional spelling.The view that ''Clodius'' represents a plebeian or politicized form has been questioned by Clodius's chief modern-era biographer.", "In ''The Patrician Tribune'', W. Jeffrey Tatum points out that the spelling is also associated with Clodius's sisters and that \"the political explanation … is almost certainly wrong.\"", "A plebeian branch of the ''gens'', the Claudii Marcelli, retained the supposedly patrician spelling, while there is some inscriptional evidence that the ''-o-'' form may also have been used on occasion by close male relatives of the \"patrician tribune\" Clodius.", "Tatum argues that the use of ''-o-'' by the \"chic\" Clodia was a fashionable affectation, and that Clodius, whose perhaps inordinately loving relationship with his sister was the subject of much gossip and insinuation, was imitating his stylish sibling.", "The linguistic variation of ''o'' for ''au'' was characteristic of the Umbrian language, of which Sabine was a branch.", "Forms using ''o'' were considered archaic or rustic in the 50s BC, and the use of ''Clodius'' would have been either a whimsical gesture of pastoral fantasy, or a trendy assertion of antiquarian authenticity.===Other Clodii of the Republic===In addition to Clodius, Clodii from the Republican era include:* Gnaeus Cornelius Lentulus Clodianus, presumably a \"Clodius\" before his adoption* Clodius Aesopus, a tragic actor in the 50s BC who may have been a freedman of one of the Clodii Pulchri.", "* Claudia, daughter of Clodius Pulcher and Fulvia, the first wife of emperor Augustus.", "* Clodia, sister of Publius Clodius Pulcher, sometimes identified in Catullus' poems as \"Lesbia\".Women of the Claudii Marcelli branch were often called \"Clodia\" in the late Republic." ], [ "Imperial era", "relief for Publius Clodius Philonicus, 70–100 ADPeople using the name ''Clodius'' during the period of the Roman Empire include:* Gaius Clodius Licinus, consul ''suffectus'' in AD 4.", "* Gaius Clodius Vestalis, possible builder of the Via Clodia* Publius Clodius Thrasea Paetus, senator and philosopher during the reign of Nero* Lucius Clodius Macer, a ''legatus'' who revolted against Nero* Publius Clodius Quirinalis, from Arelate in Gaul, teacher of rhetoric in time of Nero* Decimus Clodius Septimius Albinus, commonly known as Clodius Albinus, rival emperor 196-197* Marcus Clodius Pupienus Maximus, known as Pupienus, co-emperor 238* Titus Clodius Pupienus Pulcher Maximus, son of emperor Pupienus and suffect consul c. 235===Clodii Celsini===The Clodii Celsini continued to practice the traditional religions of antiquity in the face of Christian hegemony through at least the 4th century, when Clodius Celsinus Adelphius (see below) converted.", "Members of this branch include:* Quintus Fabius Clodius Agrippianus Celsinus, proconsul of Caria in 249 and the son of Clodius Celsinus (b.", "''ca.''", "185); see for other members of the family.", "* Clodius Celsinus Adelphius, ''praefectus urbi'' in 351.", "* Quintus Clodius Hermogenianus Olybrius, consul 379" ], [ "See also", "* Clodio the Longhair, a chieftain of the Salian Franks, sometimes called \"Clodius I\"*''Leges Clodiae'', legislation sponsored by Clodius Pulcher as tribune" ], [ "References" ], [ "Selected bibliography", "*Tatum, W. Jeffrey.", "''The Patrician Tribune: P. Clodius Pulcher''.", "Studies in the History of Greece and Rome series.", "University of North Carolina Press, 1999.Limited preview online.", "Hardcover ." ], [ "Further reading", "* Fezzi, L. ''Il tribuno Clodio''.", "Roma-Bari, Laterza, 2008.." ] ]
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[ [ "Cicero" ], [ "Introduction", "'''Marcus Tullius Cicero''' ( ; ; 3 January 106 BC – 7 December 43 BC) was a Roman statesman, lawyer, scholar, philosopher, writer and Academic skeptic, who tried to uphold optimate principles during the political crises that led to the establishment of the Roman Empire.", "His extensive writings include treatises on rhetoric, philosophy and politics.", "He is considered one of Rome's greatest orators and prose stylists and the innovator of what became known as \"Ciceronian rhetoric\".", "Cicero was educated in Rome and in Greece.", "He came from a wealthy municipal family of the Roman equestrian order, and served as consul in 63 BC.His influence on the Latin language was immense.", "He wrote more than three-quarters of extant Latin literature that is known to have existed in his lifetime, and it has been said that subsequent prose was either a reaction against or a return to his style, not only in Latin but in European languages up to the 19th century.", "Cicero introduced into Latin the arguments of the chief schools of Hellenistic philosophy and created a large amount of Latin philosophical vocabulary via lexical innovation (e.g.", "neologisms such as , ''generator'', , ''infinitio'', , ), almost 150 of which had been introduced from the translation of Greek philosophical terms, demonstrating himself as both an adept scholar of philosophy as well as a skilled translator.Though he was an accomplished orator and successful lawyer, Cicero believed his political career was his most important achievement.", "It was during his consulship that the Catiline conspiracy attempted to overthrow the government through an attack on the city by outside forces, and Cicero suppressed the revolt by summarily and controversially executing five conspirators without trial, with the support of the Senate.", "During the chaotic middle period of the first century BC, marked by civil wars and the dictatorship of Julius Caesar, Cicero championed a return to the traditional republican government.", "Following Caesar's death, Cicero became an enemy of Mark Antony in the ensuing power struggle, attacking him in a series of speeches.", "He was proscribed as an enemy of the state by the Second Triumvirate and consequently executed by soldiers operating on their behalf in 43 BC, having been intercepted during an attempted flight from the Italian peninsula.", "His severed hands and head were then, as a final revenge of Mark Antony, displayed on the Rostra.Petrarch's rediscovery of Cicero's letters is often credited for initiating the 14th-century Renaissance in public affairs, humanism, and classical Roman culture.", "According to Polish historian Tadeusz Zieliński, \"the Renaissance was above all things a revival of Cicero, and only after him and through him of the rest of Classical antiquity.\"", "The peak of Cicero's authority and prestige came during the 18th-century Enlightenment, and his impact on leading Enlightenment thinkers and political theorists such as John Locke, David Hume, Montesquieu, and Edmund Burke was substantial.", "His works rank among the most influential in global culture, and today still constitute one of the most important bodies of primary material for the writing and revision of Roman history, especially the last days of the Roman Republic." ], [ "Early life", "left''The Young Cicero Reading'' by Vincenzo Foppa (fresco, 1464), now at the Wallace Collection|leftMarcus Tullius Cicero was born on 3 January 106 BC in Arpinum, a hill town southeast of Rome.", "He belonged to the ''tribus'' Cornelia.", "His father was a well-to-do member of the equestrian order and possessed good connections in Rome.", "However, being a semi-invalid, he could not enter public life and studied extensively to compensate.", "Although little is known about Cicero's mother, Helvia, it was common for the wives of important Roman citizens to be responsible for the management of the household.", "Cicero's brother Quintus wrote in a letter that she was a thrifty housewife.Cicero's cognomen, a hereditary nickname, comes from the Latin for chickpea, .", "Plutarch explains that the name was originally given to one of Cicero's ancestors who had a cleft in the tip of his nose resembling a chickpea.", "Romans often chose down-to-earth personal surnames.", "The famous family names of Fabius, Lentulus, and Piso come from the Latin names of beans, lentils, and peas, respectively.", "Plutarch writes that Cicero was urged to change this deprecatory name when he entered politics, but refused, saying that he would make ''Cicero'' more glorious than ''Scaurus'' (\"Swollen-ankled\") and ''Catulus'' (\"Puppy\").At the age of 15, in 90 BC, Cicero started serving under Pompey Strabo and later Sulla in the Social war between Rome and its Italian allies.", "When in Rome during the turbulent plebeian tribunate of Publius Sulpicius Rufus in 88 BC which saw a short bout of fighting between the Sulpicius and Sulla, who had been elected consul for that year, Cicero found himself greatly impressed by Sulpicius' oratory even if he disagreed with his politics.", "He continued his studies at Rome, writing a pamphlet titled ''On Invention'' relating to rhetorical argumentation and studying philosophy with Greek academics who had fled the ongoing First Mithridatic War.=== Education ===During this period in Roman history, \"cultured\" meant being able to speak both Latin and Greek.", "Cicero was therefore educated in the teachings of the ancient Greek philosophers, poets and historians; as he obtained much of his understanding of the theory and practice of rhetoric from the Greek poet Archias.", "Cicero used his knowledge of Greek to translate many of the theoretical concepts of Greek philosophy into Latin, thus translating Greek philosophical works for a larger audience.", "It was precisely his broad education that tied him to the traditional Roman elite.Cicero's interest in philosophy figured heavily in his later career and led to him providing a comprehensive account of Greek philosophy for a Roman audience, including creating a philosophical vocabulary in Latin.", "In 87 BC, Philo of Larissa, the head of the Platonic Academy that had been founded by Plato in Athens about 300 years earlier, arrived in Rome.", "Cicero, \"inspired by an extraordinary zeal for philosophy\", sat enthusiastically at his feet and absorbed Carneades' Academic Skeptic philosophy.Cicero said of Plato's Dialogues, that if Zeus were to speak, he would use their language.", "He would, in due course, honor them with his own convivial dialogues.According to Plutarch, Cicero was an extremely talented student, whose learning attracted attention from all over Rome, affording him the opportunity to study Roman law under Quintus Mucius Scaevola.", "Cicero's fellow students were Gaius Marius Minor, Servius Sulpicius Rufus (who became a famous lawyer, one of the few whom Cicero considered superior to himself in legal matters), and Titus Pomponius.", "The latter two became Cicero's friends for life, and Pomponius (who later received the nickname \"Atticus\", and whose sister married Cicero's brother) would become, in Cicero's own words, \"as a second brother\", with both maintaining a lifelong correspondence.In 79 BC, Cicero left for Greece, Asia Minor and Rhodes.", "This was perhaps to avoid the potential wrath of Sulla, as Plutarch claims, though Cicero himself says it was to hone his skills and improve his physical fitness.", "In Athens he studied philosophy with Antiochus of Ascalon, the 'Old Academic' and initiator of Middle Platonism.", "In Asia Minor, he met the leading orators of the region and continued to study with them.", "Cicero then journeyed to Rhodes to meet his former teacher, Apollonius Molon, who had taught him in Rome.", "Molon helped Cicero hone the excesses in his style, as well as train his body and lungs for the demands of public speaking.", "Charting a middle path between the competing Attic and Asiatic styles, Cicero would ultimately become considered second only to Demosthenes among history's orators." ], [ "Early career", "===Early legal activity===While Cicero had feared that the law courts would be closed forever, they were reopened in the aftermath of Sulla's civil war and the purging of Sulla's political opponents in the proscriptions.", "Many of the orators which Cicero admired in his youth were now dead from age or political violence.", "His first major appearance in the courts was in 81 BC at the age of 26 when he delivered, ''Pro Quinctio'', a speech defending certain commercial transactions which Cicero had recorded and disseminated.His more famous speech defending Sextus Roscius of Ameria – – on charges of parricide in 80 BC was his first appearance in criminal court.", "In this high-profile case, Cicero accused a freedman of the dictator Sulla, Chrysogonus, of fabricating Roscius' father's proscription to obtain Roscius' family's property.", "Successful in his defence, Cicero tactfully avoided incriminating Sulla of any wrongdoing and developed a positive oratorical reputation for himself.While Plutarch claims that Cicero left Rome shortly thereafter out of fear of Sulla's response, \"most scholarly now dismiss this suggestion\" because Cicero left Rome after Sulla resigned his dictatorship.", "Cicero, for his part, later claimed that he left Rome, headed for Asia, to develop his physique and develop his oratory.", "After marrying his wife, Terentia, in 80 BC, he eventually left for Asia Minor with his brother Quintus, his friend Titus Atticus, and others on a long trip spanning most of 79 through 77 BC.", "Returning to Rome in 77 BC, Cicero again busied himself with legal defence.===Early political career===In 76 BC, at the quaestorian elections, Cicero was elected at the minimum age required – 30 years – in the first returns from the ''comitia tributa'', to the post of quaestor.", "Ex officio, he also became a member of the Senate.", "In the quaestorian lot, he was assigned to Sicily for 75 BC.", "The post, which was largely one related to financial administration in support of the state or provincial governors, proved for Cicero an important place where he could gain clients in the provinces.", "His time in Sicily saw him balance his duties – largely in terms of sending more grain back to Rome – with his support for the provincials, Roman businessmen in the area, and local potentates.", "Adeptly balancing those responsibilities, he won their gratitude.", "He was also appreciated by local Syracusans for the rediscovery of the lost tomb of Archimedes, which he personally financed.Promising to lend the Sicilians his oratorical voice, he was called on a few years after his quaestorship to prosecute the Roman province's governor Gaius Verres, for abuse of power and corruption.", "In 70 BC, at the age of 36, Cicero launched his first high-profile prosecution against Verres, an emblem of the corrupt Sullan supporters who had risen in the chaos of the civil war.", "The prosecution of Gaius Verres was a great forensic success for Cicero.", "While Verres hired the prominent lawyer, Quintus Hortensius, after a lengthy period in Sicily collecting testimonials and evidence and persuading witnesses to come forward, Cicero returned to Rome and won the case in a series of dramatic court battles.", "His unique style of oratory set him apart from the flamboyant Hortensius.", "On the conclusion of this case, Cicero came to be considered the greatest orator in Rome.", "The view that Cicero may have taken the case for reasons of his own is viable.", "Hortensius was, at this point, known as the best lawyer in Rome; to beat him would guarantee much success and the prestige that Cicero needed to start his career.", "Cicero's oratorical ability is shown in his character assassination of Verres and various other techniques of persuasion used on the jury.", "One such example is found in the speech ''In Verrem'', where he states \"with you on this bench, gentlemen, with Marcus Acilius Glabrio as your president, I do not understand what Verres can hope to achieve\".", "Oratory was considered a great art in ancient Rome and an important tool for disseminating knowledge and promoting oneself in elections, in part because there were no regular newspapers or mass media.", "Cicero was neither a patrician nor a plebeian noble; his rise to political office despite his relatively humble origins has traditionally been attributed to his brilliance as an orator.Cicero grew up in a time of civil unrest and war.", "Sulla's victory in the first of a series of civil wars led to a new constitutional framework that undermined (liberty), the fundamental value of the Roman Republic.", "Nonetheless, Sulla's reforms strengthened the position of the equestrian class, contributing to that class's growing political power.", "Cicero was both an Italian and a , but more importantly he was a Roman constitutionalist.", "His social class and loyalty to the Republic ensured that he would \"command the support and confidence of the people as well as the Italian middle classes\".", "The optimates faction never truly accepted Cicero, and this undermined his efforts to reform the Republic while preserving the constitution.", "Nevertheless, he successfully ascended the cursus honorum, holding each magistracy at or near the youngest possible age: quaestor in 75 BC (age 30), aedile in 69 BC (age 36), and praetor in 66 BC (age 39), when he served as president of the \"Reclamation\" (or extortion) Court.", "He was then elected consul at age 42." ], [ "Consulship", "''Cicero Denounces Catiline'', fresco by Cesare Maccari, 1882–1888|alt=|upright=1.2Cicero, seizing the opportunity offered by optimate fear of reform, was elected consul for the year 63 BC; he was elected with the support of every unit of the centuriate assembly, rival members of the post-Sullan establishment, and the leaders of municipalities throughout post-Social War Italy.", "His co-consul for the year, Gaius Antonius Hybrida, played a minor role.He began his consular year by opposing a land bill proposed by a plebeian tribune which would have appointed commissioners with semi-permanent authority over land reform.", "Cicero was also active in the courts, defending Gaius Rabirius from accusations of participating in the unlawful killing of plebeian tribune Lucius Appuleius Saturninus in 100 BC.", "The prosecution occurred before the and threatened to reopen conflict between the Marian and Sullan factions at Rome.", "Cicero defended the use of force as being authorised by a , which would prove similar to his own use of force under such conditions.=== Catilinarian Conspiracy ===Most famouslyin part because of his own publicityhe thwarted a conspiracy led by Lucius Sergius Catilina to overthrow the Roman Republic with the help of foreign armed forces.", "Cicero procured a ''senatus consultum ultimum'' (a recommendation from the senate attempting to legitimise the use of force) and drove Catiline from the city with four vehement speeches (the Catilinarian orations), which remain outstanding examples of his rhetorical style.", "The Orations listed Catiline and his followers' debaucheries, and denounced Catiline's senatorial sympathizers as roguish and dissolute debtors clinging to Catiline as a final and desperate hope.", "Cicero demanded that Catiline and his followers leave the city.", "At the conclusion of Cicero's first speech (which was made in the Temple of Jupiter Stator), Catiline hurriedly left the Senate.", "In his following speeches, Cicero did not directly address Catiline.", "He delivered the second and third orations before the people, and the last one again before the Senate.", "By these speeches, Cicero wanted to prepare the Senate for the worst possible case; he also delivered more evidence, against Catiline.Catiline fled and left behind his followers to start the revolution from within while he himself assaulted the city with an army of \"moral and financial bankrupts, or of honest fanatics and adventurers\".", "It is alleged that Catiline had attempted to involve the Allobroges, a tribe of Transalpine Gaul, in their plot, but Cicero, working with the Gauls, was able to seize letters that incriminated the five conspirators and forced them to confess in front of the Senate.", "The senate then deliberated upon the conspirators' punishment.", "As it was the dominant advisory body to the various legislative assemblies rather than a judicial body, there were limits to its power; however, martial law was in effect, and it was feared that simple house arrest or exile – the standard options – would not remove the threat to the state.", "At first Decimus Junius Silanus spoke for the \"extreme penalty\"; but during the debate many were swayed by Julius Caesar, who decried the precedent it would set and argued in favor of life imprisonment in various Italian towns.", "Cato the Younger then rose in defense of the death penalty and the Senate finally agreed on the matter, and came down in support of the death penalty.", "Cicero had the conspirators taken to the Tullianum, the notorious Roman prison, where they were strangled.", "Cicero himself accompanied the former consul Publius Cornelius Lentulus Sura, one of the conspirators, to the Tullianum.Cicero received the honorific \"''pater patriae''\" for his efforts to suppress the conspiracy, but lived thereafter in fear of trial or exile for having put Roman citizens to death without trial.", "While the ''senatus consultum ultimum'' gave some legitimacy to the use of force against the conspirators, Cicero also argued that Catiline's conspiracy, by virtue of its treason, made the conspirators enemies of the state and forfeited the protections intrinsically possessed by Roman citizens.", "The consuls moved decisively.", "Antonius Hybrida was dispatched to defeat Catiline in battle that year, preventing Crassus or Pompey from exploiting the situation for their own political aims.After the suppression of the conspiracy, Cicero was proud of his accomplishment.", "Some of his political enemies argued that though the act gained Cicero popularity, he exaggerated the extent of his success.", "He overestimated his popularity again several years later after being exiled from Italy and then allowed back from exile.", "At this time, he claimed that the republic would be restored along with him.Shortly after completing his consulship, in late 62 BC, Cicero arranged the purchase of a large townhouse on the Palatine Hill previously owned by Rome's richest citizen, Marcus Licinius Crassus.", "To finance the purchase, Cicero borrowed some two million sesterces from Publius Cornelius Sulla, whom he had previously defended from court.", "Cicero boasted his house was ''\"in conspectu prope totius urbis\"'' (\"in sight of nearly the whole city\"), only a short walk from the Roman Forum." ], [ "Exile and return", "In 60 BC, Julius Caesar invited Cicero to be the fourth member of his existing partnership with Pompey and Marcus Licinius Crassus, an assembly that would eventually be called the First Triumvirate.", "Cicero refused the invitation because he suspected it would undermine the Republic, and was strongly opposed to anything unconsitutional that limited the powers of the consuls, and replaced them with non-elected officials.During Caesar's consulship of 59 BC, the triumvirate had achieved many of their goals of land reform, publicani debt forgiveness, ratification of Pompeian conquests, etc.", "With Caesar leaving for his provinces, they wished to maintain their hold on politics.", "They engineered the adoption of patrician Publius Clodius Pulcher into a plebeian family and had him elected as one of the ten tribunes of the plebs for 58 BC.", "Clodius used the triumvirate's backing to push through legislation that benefited them.", "He introduced several laws (the ''leges Clodiae'') that made him popular with the people, strengthening his power base, then he turned on Cicero.", "Clodius passed a law which made it illegal to offer \"fire and water\" (i.e shelter or food) to anyone who executed a Roman citizen without a trial.", "Cicero, having executed members of the Catiline conspiracy four years previously without formal trial, was clearly the intended target.", "Furthermore, many believed that Clodius acted in concert with the triumvirate who feared that Cicero would seek to abolish many of Caesar's accomplishments while consul the year before.", "Cicero argued that the ''senatus consultum ultimum'' indemnified him from punishment, and he attempted to gain the support of the senators and consuls, especially of Pompey.Cicero grew out his hair, dressed in mourning and toured the streets.", "Clodius' gangs dogged him, hurling abuse, stones and even excrement.", "Hortensius, trying to rally to his old rival's support, was almost lynched.", "The Senate and the consuls were cowed.", "Caesar, who was still encamped near Rome, was apologetic but said he could do nothing when Cicero brought himself to grovel in the proconsul's tent.", "Everyone seemed to have abandoned Cicero.After Clodius passed a law to deny to Cicero fire and water (i.e.", "shelter) within four hundred miles of Rome, Cicero went into exile.", "He arrived at Thessalonica, on 23 May 58 BC.", "In his absence, Clodius, who lived next door to Cicero on the Palatine, arranged for Cicero's house to be confiscated by the state, and was even able to purchase a part of the property in order to extend his own house.", "After demolishing Cicero's house, Clodius had the land consecrated and symbolically erected a temple of Liberty (''aedes Libertatis'') on the vacant land.Cicero's exile caused him to fall into depression.", "He wrote to Atticus: \"Your pleas have prevented me from committing suicide.", "But what is there to live for?", "Don't blame me for complaining.", "My afflictions surpass any you ever heard of earlier\".", "After the intervention of recently elected tribune Titus Annius Milo, acting on the behalf of Pompey who wanted Cicero as a client, the Senate voted in favor of recalling Cicero from exile.", "Clodius cast the single vote against the decree.", "Cicero returned to Italy on 5 August 57 BC, landing at Brundisium.", "He was greeted by a cheering crowd, and, to his delight, his beloved daughter Tullia.", "In his ''Oratio De Domo Sua Ad Pontifices'', Cicero convinced the College of Pontiffs to rule that the consecration of his land was invalid, thereby allowing him to regain his property and rebuild his house on the Palatine.Cicero tried to re-enter politics as an independent operator, but his attempts to attack portions of Caesar's legislation were unsuccessful and encouraged Caesar to re-solidify his political alliance with Pompey and Crassus.", "The conference at Luca in 56 BC left the three-man alliance in domination of the republic's politics; this forced Cicero to recant and support the triumvirate out of fear from being entirely excluded from public life.", "After the conference Cicero lavishly praised Caesar's achievements, got the Senate to vote a thanksgiving for Caesar's victories and grant money to pay his troops.", "He also delivered a speech 'On the consular provinces' () which checked an attempt by Caesar's enemies to strip him of his provinces in Gaul.", "After this, a cowed Cicero concentrated on his literary works.", "It is uncertain whether he was directly involved in politics for the following few years." ], [ "Governorship of Cilicia", "In 51 BC he reluctantly accepted a promagistracy (as proconsul) in Cilicia for the year; there were few other former consuls eligible as a result of a legislative requirement enacted by Pompey in 52 BC specifying an interval of five years between a consulship or praetorship and a provincial command.", "He served as proconsul of Cilicia from May 51 BC, arriving in the provinces three months later around August.", "In 53 BC Marcus Licinius Crassus had been defeated by the Parthians at the Battle of Carrhae.", "This opened the Roman East for a Parthian invasion, causing unrest in Syria and Cilicia.", "Cicero restored calm by his mild system of government.", "He discovered that a great amount of public property had been embezzled by corrupt previous governors and members of their staff, and did his utmost to restore it.", "Thus he greatly improved the condition of the cities.", "He retained the civil rights of, and exempted from penalties, the men who gave the property back.", "Besides this, he was extremely frugal in his outlays for staff and private expenses during his governorship, and this made him highly popular among the natives.Besides his activity in ameliorating the hard pecuniary situation of the province, Cicero was also creditably active in the military sphere.", "Early in his governorship he received information that prince Pacorus, son of Orodes II the king of the Parthians, had crossed the Euphrates, and was ravaging the Syrian countryside and had even besieged Cassius (the interim Roman commander in Syria) in Antioch.", "Cicero eventually marched with two understrength legions and a large contingent of auxiliary cavalry to Cassius's relief.", "Pacorus and his army had already given up on besieging Antioch and were heading south through Syria, ravaging the countryside again.", "Cassius and his legions followed them, harrying them wherever they went, eventually ambushing and defeating them near Antigonea.Another large troop of Parthian horsemen was defeated by Cicero's cavalry who happened to run into them while scouting ahead of the main army.", "Cicero next defeated some robbers who were based on Mount Amanus and was hailed as imperator by his troops.", "Afterwards he led his army against the independent Cilician mountain tribes, besieging their fortress of Pindenissum.", "It took him 47 days to reduce the place, which fell in December.", "On 30 July 50 BC Cicero left the province to his brother Quintus, who had accompanied him on his governorship as his legate.", "On his way back to Rome he stopped in Rhodes and then went to Athens, where he caught up with his old friend Titus Pomponius Atticus and met men of great learning." ], [ "Julius Caesar's civil war", "Cicero arrived in Rome on 4 January 49 BC.", "He stayed outside the pomerium, to retain his promagisterial powers: either in expectation of a triumph or to retain his independent command authority in the coming civil war.", "The struggle between Pompey and Julius Caesar grew more intense in 50 BC.", "Cicero favored Pompey, seeing him as a defender of the senate and Republican tradition, but at that time avoided openly alienating Caesar.", "When Caesar invaded Italy in 49 BC, Cicero fled Rome.", "Caesar, seeking an endorsement by a senior senator, courted Cicero's favor, but even so Cicero slipped out of Italy and traveled to Dyrrhachium where Pompey's staff was situated.", "Cicero traveled with the Pompeian forces to Pharsalus in Macedonia in 48 BC, though he was quickly losing faith in the competence and righteousness of the Pompeian side.", "Eventually, he provoked the hostility of his fellow senator Cato, who told him that he would have been of more use to the cause of the ''optimates'' if he had stayed in Rome.", "After Caesar's victory at the Battle of Pharsalus on 9 August, Cicero refused to take command of the Pompeian forces and continue the war.", "He returned to Rome, still as a promagistrate with his lictors, in 47 BC, and dismissed them upon his crossing the pomerium and renouncing his command.", "In a letter to Varro on , Cicero outlined his strategy under Caesar's dictatorship.", "Cicero, however, was taken by surprise when the ''Liberatores'' assassinated Caesar on the ides of March, 44 BC.", "Cicero was not included in the conspiracy, even though the conspirators were sure of his sympathy.", "Marcus Junius Brutus called out Cicero's name, asking him to restore the republic when he lifted his bloodstained dagger after the assassination.", "A letter Cicero wrote in February 43 BC to Trebonius, one of the conspirators, began, \"How I could wish that you had invited me to that most glorious banquet on the Ides of March!\"", "Cicero became a popular leader during the period of instability following the assassination.", "He had no respect for Mark Antony, who was scheming to take revenge upon Caesar's murderers.", "In exchange for amnesty for the assassins, he arranged for the Senate to agree not to declare Caesar to have been a tyrant, which allowed the Caesarians to have lawful support and kept Caesar's reforms and policies intact." ], [ "Opposition to Mark Antony and death", "Marcus Tullius Cicero dragged from his litter and assassinated by soldiers under the command of Marc Antony 43 BC (1880 illustration)In April 43 BC, \"diehard republicans\" may have revived the ancient position of ''princeps senatus'' (leader of the senate) for Cicero.", "This position had been very prestigious until the constitutional reforms of Sulla in 82–80 BC, which removed most of its importance.On the other side, Antony was consul and leader of the Caesarian faction, and unofficial executor of Caesar's public will.", "Relations between the two were never friendly and worsened after Cicero claimed that Antony was taking liberties in interpreting Caesar's wishes and intentions.", "Octavian was Caesar's adopted son and heir.", "After he returned to Italy, Cicero began to play him against Antony.", "He praised Octavian, declaring he would not make the same mistakes as his father.", "He attacked Antony in a series of speeches he called the ''Philippics'', named after Demosthenes's denunciations of Philip II of Macedon.", "At the time, Cicero's popularity as a public figure was unrivalled.", "''The Vengeance of Fulvia'' by Francisco Maura y Montaner, 1888 depicting Fulvia inspecting the severed head of CiceroCicero supported Decimus Junius Brutus Albinus as governor of Cisalpine Gaul (''Gallia Cisalpina'') and urged the Senate to name Antony an enemy of the state.", "The speech of Lucius Piso, Caesar's father-in-law, delayed proceedings against Antony.", "Antony was later declared an enemy of the state when he refused to lift the siege of Mutina, which was in the hands of Decimus Brutus.", "Cicero's plan to drive out Antony failed.", "Antony and Octavian reconciled and allied with Lepidus to form the Second Triumvirate after the successive battles of Forum Gallorum and Mutina.", "The alliance came into official existence with the ''lex Titia'', passed on 27 November 43 BC, which gave each triumvir a consular ''imperium'' for five years.", "The Triumvirate immediately began a proscription of their enemies, modeled after that of Sulla in 82 BC.", "Cicero and all of his contacts and supporters were numbered among the enemies of the state, even though Octavian argued for two days against Cicero being added to the list.Cicero's death (France, 15th century)Cicero was one of the most viciously and doggedly hunted among the proscribed.", "He was viewed with sympathy by a large segment of the public and many people refused to report that they had seen him.", "He was caught on 7 December 43 BC leaving his villa in Formiae in a litter heading to the seaside, where he hoped to embark on a ship destined for Macedonia.", "When his killers – Herennius (a Centurion) and Popilius (a Tribune) – arrived, Cicero's own slaves said they had not seen him, but he was given away by Philologus, a freedman of his brother Quintus Cicero.Cicero about age 60, from a marble bustAs reported by Seneca the Elder, according to the historian Aufidius Bassus, Cicero's last words are said to have been:He bowed to his captors, leaning his head out of the litter in a gladiatorial gesture to ease the task.", "By baring his neck and throat to the soldiers, he was indicating that he would not resist.", "According to Plutarch, Herennius first slew him, then cut off his head.", "On Antony's instructions his hands, which had penned the Philippics against Antony, were cut off as well; these were nailed along with his head on the Rostra in the Forum Romanum according to the tradition of Marius and Sulla, both of whom had displayed the heads of their enemies in the Forum.", "Cicero was the only victim of the proscriptions who was displayed in that manner.", "According to Cassius Dio, in a story often mistakenly attributed to Plutarch, Antony's wife Fulvia took Cicero's head, pulled out his tongue, and jabbed it repeatedly with her hairpin in final revenge against Cicero's power of speech.Cicero's son, Marcus Tullius Cicero Minor, during his year as a consul in 30 BC, avenged his father's death, to a certain extent, when he announced to the Senate Mark Antony's naval defeat at Actium in 31 BC by Octavian.Octavian is reported to have praised Cicero as a patriot and a scholar of meaning in later times, within the circle of his family.", "However, it was Octavian's acquiescence that had allowed Cicero to be killed, as Cicero was condemned by the new triumvirate.Cicero's career as a statesman was marked by inconsistencies and a tendency to shift his position in response to changes in the political climate.", "His indecision may be attributed to his sensitive and impressionable personality; he was prone to overreaction in the face of political and private change.", "\"Would that he had been able to endure prosperity with greater self-control, and adversity with more fortitude!\"", "wrote C. Asinius Pollio, a contemporary Roman statesman and historian." ], [ "Personal life and family", "Cicero married Terentia probably at the age of 27, in 79 BC.", "According to the upper-class mores of the day it was a marriage of convenience but lasted harmoniously for nearly 30 years.", "Terentia's family was wealthy, probably the plebeian noble house of Terenti Varrones, thus meeting the needs of Cicero's political ambitions in both economic and social terms.", "She had a half-sister named Fabia, who as a child had become a Vestal Virgin, a great honour.", "Terentia was a strong-willed woman and (citing Plutarch) \"took more interest in her husband's political career than she allowed him to take in household affairs\".In the 50s BC, Cicero's letters to Terentia became shorter and colder.", "He complained to his friends that Terentia had betrayed him but did not specify in which sense.", "Perhaps the marriage could not outlast the strain of the political upheaval in Rome, Cicero's involvement in it, and various other disputes between the two.", "The divorce appears to have taken place in 51 BC or shortly before.", "In 46 or 45 BC, Cicero married a young girl, Publilia, who had been his ward.", "It is thought that Cicero needed her money, particularly after having to repay the dowry of Terentia, who came from a wealthy family.", "Although his marriage to Terentia was one of convenience, it is commonly known that Cicero held great love for his daughter Tullia.", "When she suddenly became ill in February 45 BC and died after having seemingly recovered from giving birth to a son in January, Cicero was stunned.", "\"I have lost the one thing that bound me to life,\" he wrote to Atticus.", "Atticus told him to come for a visit during the first weeks of his bereavement, so that he could comfort him when his pain was at its greatest.", "In Atticus's large library, Cicero read everything that the Greek philosophers had written about overcoming grief, \"but my sorrow defeats all consolation.\"", "Caesar and Brutus, as well as Servius Sulpicius Rufus, sent him letters of condolence.Cicero hoped that his son Marcus would become a philosopher like him, but Marcus himself wished for a military career.", "He joined the army of Pompey in 49 BC, and after Pompey's defeat at Pharsalus 48 BC, he was pardoned by Caesar.", "Cicero sent him to Athens to study as a disciple of the peripatetic philosopher Kratippos in 48 BC, but he used this absence from \"his father's vigilant eye\" to \"eat, drink, and be merry.\"", "After Cicero's death, he joined the army of the ''Liberatores'' but was later pardoned by Augustus.", "Augustus's bad conscience for not having objected to Cicero's being put on the proscription list during the Second Triumvirate led him to aid considerably Marcus Minor's career.", "He became an augur and was nominated consul in 30 BC together with Augustus.", "As such, he was responsible for revoking the honors of Mark Antony, who was responsible for the proscription and could in this way take revenge.", "Later he was appointed proconsul of Syria and the province of Asia." ], [ "Legacy", "Henry VIII's childhood copy of ''De Officiis'', bearing the inscription in his hand, \"Thys boke is myne Prynce Henry\"Cicero has been traditionally considered the master of Latin prose, with Quintilian declaring that Cicero was \"not the name of a man, but of eloquence itself.\"", "The English words ''Ciceronian'' (meaning \"eloquent\") and ''cicerone'' (meaning \"local guide\") derive from his name.", "He is credited with transforming Latin from a modest utilitarian language into a versatile literary medium capable of expressing abstract and complicated thoughts with clarity.", "Julius Caesar praised Cicero's achievement by saying \"it is more important to have greatly extended the frontiers of the Roman spirit than the frontiers of the Roman empire\".", "According to John William Mackail, \"Cicero's unique and imperishable glory is that he created the language of the civilized world, and used that language to create a style which nineteen centuries have not replaced, and in some respects have hardly altered.", "\"Cicero was also an energetic writer with an interest in a wide variety of subjects, in keeping with the Hellenistic philosophical and rhetorical traditions in which he was trained.", "The quality and ready accessibility of Ciceronian texts favored very wide distribution and inclusion in teaching curricula, as suggested by a graffito at Pompeii, admonishing: \"You will like Cicero, or you will be whipped\".Cicero was greatly admired by influential Church Fathers such as Augustine of Hippo, who credited Cicero's lost ''Hortensius'' for his eventual conversion to Christianity, and St. Jerome, who had a feverish vision in which he was accused of being \"follower of Cicero and not of Christ\" before the judgment seat.This influence further increased after the Early Middle Ages in Europe, where more of his writings survived than any other Latin author.", "Medieval philosophers were influenced by Cicero's writings on natural law and innate rights.Petrarch's rediscovery of Cicero's letters provided the impetus for searches for ancient Greek and Latin writings scattered throughout European monasteries, and the subsequent rediscovery of classical antiquity led to the Renaissance.", "Subsequently, Cicero became synonymous with classical Latin to such an extent that a number of humanist scholars began to assert that no Latin word or phrase should be used unless it appeared in Cicero's works, a stance criticised by Erasmus.His voluminous correspondence, much of it addressed to his friend Atticus, has been especially influential, introducing the art of refined letter writing to European culture.", "Cornelius Nepos, the first century BC biographer of Atticus, remarked that Cicero's letters contained such a wealth of detail \"concerning the inclinations of leading men, the faults of the generals, and the revolutions in the government\" that their reader had little need for a history of the period.Among Cicero's admirers were Desiderius Erasmus, Martin Luther, and John Locke.", "Following the invention of Johannes Gutenberg's printing press, ''De Officiis'' was the second book printed in Europe, after the Gutenberg Bible.", "Scholars note Cicero's influence on the rebirth of religious toleration in the 17th century.Cicero was especially popular with the Philosophes of the 18th century, including Edward Gibbon, Diderot, David Hume, Montesquieu, and Voltaire.", "Gibbon wrote of his first experience reading the author's collective works thus: \"I tasted the beauty of the language; I breathed the spirit of freedom; and I imbibed from his precepts and examples the public and private sense of a man...after finishing the great author, a library of eloquence and reason, I formed a more extensive plan of reviewing the Latin classics...\"Voltaire called Cicero \"the greatest as well as the most elegant of Roman philosophers\" and even staged a play based on Cicero's role in the Catilinarian conspiracy, called ''Rome Sauvée, ou Catilina'', to \"make young people who go to the theatre acquainted with Cicero.\"", "Voltaire was spurred to pen the drama as a rebuff to his rival Claude Prosper Jolyot de Crébillon's own play ''Catilina'', which had portrayed Cicero as a coward and villain who hypocritically married his own daughter to Catiline.Montesquieu produced his \"Discourse on Cicero\" in 1717, in which he heaped praise on the author because he rescued \"philosophy from the hands of scholars, and freed it from the confusion of a foreign language\".", "Montesquieu went on to declare that Cicero was \"of all the ancients, the one who had the most personal merit, and whom I would prefer to resemble.", "\"Internationally, Cicero the republican inspired the Founding Fathers of the United States and the revolutionaries of the French Revolution.", "John Adams said, \"As all the ages of the world have not produced a greater statesman and philosopher united than Cicero, his authority should have great weight.\"", "Thomas Jefferson names Cicero as one of a handful of major figures who contributed to a tradition \"of public right\" that informed his draft of the Declaration of Independence and shaped American understandings of \"the common sense\" basis for the right of revolution.", "Camille Desmoulins said of the French republicans in 1789 that they were \"mostly young people who, nourished by the reading of Cicero at school, had become passionate enthusiasts for liberty\".Jim Powell starts his book on the history of liberty with the sentence: \"Marcus Tullius Cicero expressed principles that became the bedrock of liberty in the modern world.", "\"Likewise, no other ancient personality has inspired as much venomous dislike as Cicero, especially in more modern times.", "His commitment to the values of the Republic accommodated a hatred of the poor and persistent opposition to the advocates and mechanisms of popular representation.", "Friedrich Engels referred to him as \"the most contemptible scoundrel in history\" for upholding republican \"democracy\" while at the same time denouncing land and class reforms.", "Cicero has faced criticism for exaggerating the democratic qualities of republican Rome, and for defending the Roman oligarchy against the popular reforms of Caesar.", "Michael Parenti admits Cicero's abilities as an orator, but finds him a vain, pompous and hypocritical personality who, when it suited him, could show public support for popular causes that he privately despised.", "Parenti presents Cicero's prosecution of the Catiline conspiracy as legally flawed at least, and possibly unlawful.Cicero also had an influence on modern astronomy.", "Nicolaus Copernicus, searching for ancient views on earth motion, said that he \"first ... found in Cicero that Hicetas supposed the earth to move.", "\"Notably, \"Cicero\" was the name attributed to size 12 font in typesetting table drawers.", "For ease of reference, type sizes 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, and 20 were all given different names." ], [ "Works", "''Marci Tullii Ciceronis Opera Omnia'' (1566)Cicero was declared a righteous pagan by the Early Church, and therefore many of his works were deemed worthy of preservation.", "Subsequent Roman and medieval Christian writers quoted liberally from his works ''De re publica'' (''On the Commonwealth'') and ''De Legibus'' (''On the Laws''), and much of his work has been recreated from these surviving fragments.", "Cicero also articulated an early, abstract conceptualization of rights, based on ancient law and custom.", "Of Cicero's books, six on rhetoric have survived, as well as parts of seven on philosophy.", "Of his speeches, 88 were recorded, but only 52 survive." ], [ "In archaeology", "Cicero's great repute in Italy has led to numerous ruins being identified as having belonged to him, though none have been substantiated with absolute certainty.", "In Formia, two Roman-era ruins are popularly believed to be Cicero's mausoleum, the ''Tomba di Cicerone'', and the villa where he was assassinated in 43 BC.", "The latter building is centered around a central hall with Doric columns and a coffered vault, with a separate nymphaeum, on five acres of land near Formia.", "A modern villa was built on the site after the Rubino family purchased the land from Ferdinand II of the Two Sicilies in 1868.Cicero's supposed tomb is a 24-meter (79 feet) tall tower on an ''opus quadratum'' base on the ancient Via Appia outside of Formia.", "Some suggest that it is not in fact Cicero's tomb, but a monument built on the spot where Cicero was intercepted and assassinated while trying to reach the sea.In Pompeii, a large villa excavated in the mid 18th century just outside the Herculaneum Gate was widely believed to have been Cicero's, who was known to have owned a holiday villa in Pompeii he called his ''Pompeianum''.", "The villa was stripped of its fine frescoes and mosaics and then re-buried after 1763 – it has yet to be re-excavated.", "However, contemporaneous descriptions of the building from the excavators combined with Cicero's own references to his ''Pompeianum'' differ, making it unlikely that it is Cicero's villa.In Rome, the location of Cicero's house has been roughly identified from excavations of the Republican-era stratum on the northwestern slope of the Palatine Hill.", "Cicero's ''domus'' has long been known to have stood in the area, according to his own descriptions and those of later authors, but there is some debate about whether it stood near the base of the hill, very close to the Roman Forum, or nearer to the summit.", "During his life the area was the most desirable in Rome, densely occupied with Patrician houses including the ''Domus Publica'' of Julius Caesar and the home of Cicero's mortal enemy Clodius." ], [ "Notable fictional portrayals", "In Dante's 1320 poem the ''Divine Comedy'', the author encounters Cicero, among other philosophers, in Limbo.", "Ben Jonson dramatised the conspiracy of Catiline in his play ''Catiline His Conspiracy'', featuring Cicero as a character.", "Cicero also appears as a minor character in William Shakespeare's play ''Julius Caesar''.Cicero was portrayed on the motion picture screen by British actor Alan Napier in the 1953 film ''Julius Caesar'', based on Shakespeare's play.", "He has also been played by such noted actors as Michael Hordern (in ''Cleopatra''), and André Morell (in the 1970 ''Julius Caesar'').", "Most recently, Cicero was portrayed by David Bamber in the HBO series ''Rome'' (2005–2007) and appeared in both seasons.In the historical novel series ''Masters of Rome'', Colleen McCullough presents a not-so-flattering depiction of Cicero's career, showing him struggling with an inferiority complex and vanity, morally flexible and fatally indiscreet, while his rival Julius Caesar is shown in a more approving light.", "Cicero is portrayed as a hero in the novel ''A Pillar of Iron'' by Taylor Caldwell (1965).", "Robert Harris' novels ''Imperium'', ''Lustrum'' (published under the name ''Conspirata'' in the United States) and ''Dictator'' comprise a three-part series based on the life of Cicero.", "In these novels Cicero's character is depicted in a more favorable way than in those of McCullough, with his positive traits equaling or outweighing his weaknesses (while conversely Caesar is depicted as more sinister than in McCullough).", "Cicero is a major recurring character in the ''Roma Sub Rosa'' series of mystery novels by Steven Saylor.", "He also appears several times as a peripheral character in John Maddox Roberts' ''SPQR'' series.Samuel Barnett portrays Cicero in a 2017 audio drama series pilot produced by Big Finish Productions.", "A full series was released the following year.", "All episodes are written by David Llewellyn and directed and produced by Scott Handcock." ], [ "See also", "* Caecilia Attica* Caecilia Metella (daughter of Celer)* ''Civis romanus sum''* Clausula (rhetoric)* ''A Dialogue Concerning Oratorical Partitions''* ''E pluribus unum''* ''Esse quam videri''* ''Ipse dixit''* List of ancient Romans* Lorem ipsum* Marcantonius Majoragio* Marcus Tullius Tiro* Marius Nizolius* Otium* ''Socratici viri''* Tempest in a teapot* Translation" ], [ "Notes" ], [ "References", "=== Citations ====== Modern sources ===* * * * * * * * * * * * * * * Reprinted 1968.", "* * * * * * * * * * * === Ancient sources ===* * * * * * * ** ** ** ** **" ], [ "Further reading", "* Boissier, Gaston, Cicéron et ses amis.", "Étude sur la société romaine du temps de César (1884)* * Gildenhard, Ingo (2011).", "''Creative Eloquence: The Construction of Reality in Cicero's Speeches''.", "Oxford/New York: Oxford University Press.", "* Hamza, Gabor, L'optimus status civitatis di Cicerone e la sua tradizione nel pensiero politico.", "In: Tradizione romanistica e Costituzione.", "Cinquanta anni della Corte Costituzionale della Repubblica Italiana.", "vol.", "II.", "Napoli, 2006.1455–1468.", "* Hamza, Gabor, Ciceros Verhältnis zu seinen Quellen, mit besonderer Berücksichtigung der Darstellung der Staatslehre in De re publica.", "KLIO – Beiträge zur alten Geschichte 67 (1985) 492–497.", "* Hamza, Gabor, Cicero und der Idealtypus des iurisconsultus.", "Helixon 22–27 (1982–1987) 281–296.", "* Hamza, Gabor, Il potere (lo Stato) nel pensiero di Cicerone e la sua attualità.", "Revista Internacional de Derecho Romano (RIDROM) 10 (2013) 1–25.Revista Internacional de Derecho Romano – Index* Hamza, Gabor, Zur Interpretation des Naturrechts in den Werken von Cicero.", "Pázmány Law Review 2 (2014) 5–15.", "* * * * * * *" ], [ "External links", "'''Works by Cicero'''* Works by Cicero at Perseus Digital Library* * * * * Works by Cicero at the Stoic Therapy eLibrary* The Latin Library (Latin): Works of Cicero* Dickinson College Commentaries: ''Against Verres 2.1.53–86''* Dickinson College Commentaries: ''On Pompey's Command (De Imperio) 27–49''* Horace MS 1b Laelius de Amicitia at OPenn* Lewis E 66 Epistolae ad familiares (Letters to friends)'''Biographies and descriptions of Cicero's time'''Plutarch's biography of Cicero contained in the ''Parallel Lives''* ''Life of Cicero'' by Anthony Trollope, Volume I & Volume II* ''Cicero'' by Rev.", "W. Lucas Collins (''Ancient Classics for English Readers'')* ''Roman life in the days of Cicero'' by Rev.", "Alfred J.", "Church* ''Social life at Rome in the Age of Cicero'' by W. Warde Fowler* * Dryden's translation of ''Cicero'' from Plutarch's ''Parallel Lives''* At Middlebury College website*" ] ]
wikipedia
[ [ "Consul" ], [ "Introduction", "'''Consul''' (abbrev.", "''cos.", "''; Latin plural ''consules'') was the title of one of the two chief magistrates of the Roman Republic, and subsequently also an important title under the Roman Empire.", "The title was used in other European city-states through antiquity and the Middle Ages, in particular in the Republics of Genoa and Pisa, then revived in modern states, notably in the First French Republic.", "The related adjective is '''consular''', from the Latin ''consularis''.This usage contrasts with modern terminology, where a consul is a type of diplomat." ], [ "Roman consul", "A consul held the highest elected political office of the Roman Republic (509 to 27 BC), and ancient Romans considered the consulship the highest level of the ''cursus honorum'' (an ascending sequence of public offices to which politicians aspired).", "Consuls were elected to office and held power for one year.", "There were always two consuls in power at any time." ], [ "Other uses in antiquity", "===Private sphere===It was not uncommon for an organization under Roman private law to copy the terminology of state and city institutions for its own statutory agents.", "The founding statute, or contract, of such an organisation was called ''lex'', 'law'.", "The people elected each year were patricians, members of the upper class.===City-states===While many cities, including the Gallic states and the Carthaginian Republic, had a double-headed chief magistracy, another title was often used, such as the Punic ''sufet'', ''Duumvir'', or native styles like ''Meddix''." ], [ "Medieval city-states, communes and municipalities", "Caffaro di Rustico da Caschifellone, statesman of the Genoese Republic in the 12th century, for which he served eight terms as a consul.|282x282px=== Republic of Genoa ===The city-state of Genoa, unlike ancient Rome, bestowed the title of ''consul'' on various state officials, not necessarily restricted to the highest.", "Among these were Genoese officials stationed in various Mediterranean ports, whose role included helping Genoese merchants and sailors in difficulties with the local authorities.", "Great Britain reciprocated by appointing consuls to Genoa from 1722.This institution, with its name, was later emulated by other powers and is reflected in the modern usage of the word (see Consul (representative)).=== Republic of Pisa ===In addition to the Genoese Republic, the Republic of Pisa also took the form of \"Consul\" in the early stages of its government.", "The Consulate of the Republic of Pisa was the major government institution present in Pisa between the 11th and 12th centuries.", "Despite losing space within the government since 1190 in favor of the Podestà, for some periods of the 13th century some citizens were again elected as consuls.=== Other uses in the Medieval period ===In this painting, Alphonse, Count of Poitiers and Count of Toulouse takes an oath before the Consuls of the town of Agen, with his right hand on the town ordinances, committing himself to recognize the autonomy of the town's commune, while sitting on a pedestal.", "The consul administering the oath is forced to go on his knees, symbolizing Alphonse's lordship and the town's loyalty.Throughout most of southern France, a consul ( or '''') was an office equivalent to the of the north and roughly similar with English aldermen.", "The most prominent were those of Bordeaux and Toulouse, which came to be known as jurats and capitouls, respectively.", "The capitouls of Toulouse were granted transmittable nobility.", "In many other smaller towns the first consul was the equivalent of a mayor today, assisted by a variable number of secondary consuls and jurats.", "His main task was to levy and collect tax.The Dukes of Gaeta often used also the title of \"consul\" in its Greek form \"Hypatos\" (see List of Hypati and Dukes of Gaeta)." ], [ "French Revolution", "===French Republic 1799–1804===A portrait of the three consuls, Jean-Jacques-Régis de Cambacérès, Napoleon Bonaparte and Charles-François Lebrun (left to right)After Napoleon Bonaparte staged a coup against the Directory government in November 1799, the French Republic adopted a constitution which conferred executive powers upon three consuls, elected for a period of ten years.", "In reality, the first consul, Bonaparte, dominated his two colleagues and held supreme power, soon making himself consul for life (1802) and eventually, in 1804, emperor.The office was held by:* Napoleon Bonaparte, Emmanuel-Joseph Sieyès, Roger Ducos, provisional consuls (10 November – 12 December 1799)* Napoleon Bonaparte (first consul), Jean-Jacques Cambacérès (second consul), Charles-François Lebrun (third consul), consuls (12 December 1799 – 18 May 1804)===Bolognese Republic, 1796===The short-lived Bolognese Republic, proclaimed in 1796 as a French client republic in the Central Italian city of Bologna, had a government consisting of nine consuls and its head of state was the ''Presidente del Magistrato'', i.e., chief magistrate, a presiding office held for four months by one of the consuls.", "Bologna already had consuls at some parts of its Medieval history.===Roman Republic, 1798–1800===The French-sponsored Roman Republic (15 February 1798 – 23 June 1800) was headed by multiple consuls:* Francesco Riganti, Carlo Luigi Costantini, Duke Bonelli-Crescenzi, Antonio Bassi, Gioacchino Pessuti, Angelo Stampa, Domenico Maggi, provisional consuls (15 February – 20 March 1798)* Liborio Angelucci, Giacomo De Mattheis, Panazzi, Reppi, Ennio Quirino Visconti, consuls (20 March – September 1798)* Brigi, Calisti, Francesco Pierelli, Giuseppe Rey, Federico Maria Domenico Michele, Zaccaleoni, consuls (September – 24 July 1799)Consular rule was interrupted by the Neapolitan occupation (27 November – 12 December 1798), which installed a Provisional Government:* Prince Giambattista Borghese, Prince Paolo-Maria Aldobrandini, Prince Gibrielli, Marchese Camillo Massimo, Giovanni Ricci (29 November 1798 - 12 December 1798)Rome was occupied by France (11 July – 28 September 1799) and again by Naples (30 September 1799 – 23 June 1800), bringing an end to the Roman Republic." ], [ "Revolutionary Greece, 1821", "Among the many petty local republics that were formed during the first year of the Greek Revolution, prior to the creation of a unified Provisional Government at the First National Assembly at Epidaurus, were:* The Consulate of Argos (from 26 May 1821, under the Senate of the Peloponnese) had a ''single'' head of state, styled consul, 28 March 1821 – 26 May 1821: Stamatellos Antonopoulos* The Consulate of East Greece (Livadeia) (from 15 November 1821, under the Areopagus of East Greece) was headed 1 April 1821 – 15 November 1821 by three consuls: Lambros Nakos, Ioannis Logothetis & Ioannis Filon''Note: in Greek, the term for \"consul\" is \"hypatos\" (ὕπατος), which translates as \"supreme one\", and hence does not necessarily imply a joint office.''" ], [ "Paraguay, 1813–1844", "In between a series of juntas and various other short-lived regimes, the young republic was governed by \"consuls of the republic\", with two consuls alternating in power every 4 months:* 12 October 1813 – 12 February 1814, José Gaspar Rodríguez de Francia y Velasco* 12 February 1814 – 12 June 1814, Fulgencio Yegros y Franco de Torres* 12 June 1814 – 3 October 1814, José Gaspar Rodríguez de Francia y Velasco; he stayed on as \"supreme dictator\" 3 October 1814 – 20 September 1840 (from 6 June 1816 styled \"perpetual supreme dictator\")After a few presidents of the Provisional Junta, there were again consuls of the republic, 14 March 1841 – 13 March 1844 (ruling jointly, but occasionally styled \"first consul\", \"second consul\"): Carlos Antonio López Ynsfrán (b.", "1792 – d. 1862) + Mariano Roque Alonzo Romero (d. 1853) (the lasts of the aforementioned juntistas, Commandant-General of the Army)Thereafter all republican rulers were styled \"president\"." ], [ "Modern uses of the term", "In modern terminology, a consul is a type of diplomat.", "The ''American Heritage Dictionary'' defines '''consul''' as \"an official appointed by a government to reside in a foreign country and represent its interests there.\"", "''The Devil's Dictionary'' defines '''Consul''' as \"in American politics, a person who having failed to secure an office from the people is given one by the Administration on condition that he leave the country\".In most governments, the consul is the head of the consular section of an embassy, and is responsible for all consular services such as immigrant and non-immigrant visas, passports, and citizen services for expatriates living or traveling in the host country.A less common modern usage is when the consul of one country takes a governing role in the host country." ], [ "See also", "Differently named, but same function* Captain Regent (similar modern position in San Marino's government)* Consularis (Roman gubernatorial style)Modern UN System * Consulate" ], [ "Sources and references", "* WorldStatesmen.org, see each present country'''Specific'''" ] ]
wikipedia
[ [ "List of equations in classical mechanics" ], [ "Introduction", "Classical mechanics is the branch of physics used to describe the motion of macroscopic objects.", "It is the most familiar of the theories of physics.", "The concepts it covers, such as mass, acceleration, and force, are commonly used and known.", "The subject is based upon a three-dimensional Euclidean space with fixed axes, called a frame of reference.", "The point of concurrency of the three axes is known as the origin of the particular space.Classical mechanics utilises many equations—as well as other mathematical concepts—which relate various physical quantities to one another.", "These include differential equations, manifolds, Lie groups, and ergodic theory.", "This article gives a summary of the most important of these.This article lists equations from Newtonian mechanics, see analytical mechanics for the more general formulation of classical mechanics (which includes Lagrangian and Hamiltonian mechanics)." ], [ "Classical mechanics", "===Mass and inertia=== Quantity (common name/s) (Common) symbol/s Defining equation SI units Dimension Linear, surface, volumetric mass density ''λ'' or ''μ'' (especially in acoustics, see below) for Linear, ''σ'' for surface, ''ρ'' for volume.", "kg m−''n'', ''n'' = 1, 2, 3 M L−''n'' Moment of mass '''m''' (No common symbol) Point mass:Discrete masses about an axis :Continuum of mass about an axis : kg m M L Center of mass '''r'''com(Symbols vary) ''i''-th moment of mass Discrete masses:Mass continuum: m L 2-Body reduced mass ''m''12, ''μ'' Pair of masses = ''m''1 and ''m''2 kg M Moment of inertia (MOI) ''I'' Discrete Masses:Mass continuum: kg m2 M L2===Derived kinematic quantities===Kinematic quantities of a classical particle: mass ''m'', position '''r''', velocity '''v''', acceleration '''a'''.", "Quantity (common name/s) (Common) symbol/s Defining equation SI units Dimension Velocity '''v''' m s−1 L T−1 Acceleration '''a''' m s−2 L T−2 Jerk '''j''' m s−3 L T−3 Jounce '''s''' m s−4 L T−4 Angular velocity '''ω''' rad s−1 T−1 Angular Acceleration '''α''' rad s−2 T−2 Angular jerk '''ζ''' rad s−3 T−3===Derived dynamic quantities===Angular momenta of a classical object.", "'''Left:''' intrinsic \"spin\" angular momentum '''S''' is really orbital angular momentum of the object at every point,'''right:''' extrinsic orbital angular momentum '''L''' about an axis,'''top:''' the moment of inertia tensor '''I''' and angular velocity '''ω''' ('''L''' is not always parallel to '''ω''')'''bottom:''' momentum '''p''' and its radial position '''r''' from the axis.The total angular momentum (spin + orbital) is '''J'''.", "Quantity (common name/s) (Common) symbol/s Defining equation SI units Dimension Momentum '''p''' kg m s−1 M L T−1 Force '''F''' N = kg m s−2 M L T−2 Impulse '''J''', Δ'''p''', '''I''' kg m s−1 M L T−1 Angular momentum about a position point '''r'''0, '''L''', '''J''', '''S''' Most of the time we can set '''r'''0 = '''0''' if particles are orbiting about axes intersecting at a common point.", "kg m2 s−1 M L2 T−1 Moment of a force about a position point '''r'''0,Torque '''τ''', '''M''' N m = kg m2 s−2 M L2 T−2 Angular impulse Δ'''L''' (no common symbol) kg m2 s−1 M L2 T−1===General energy definitions=== Quantity (common name/s) (Common) symbol/s Defining equation SI units Dimension Mechanical work due to a Resultant Force ''W'' J = N m = kg m2 s−2 M L2 T−2 Work done ON mechanical system, Work done BY ''W''ON, ''W''BY J = N m = kg m2 s−2 M L2 T−2 Potential energy ''φ'', Φ, ''U'', ''V'', ''Ep'' J = N m = kg m2 s−2 M L2 T−2 Mechanical power ''P'' W = J s−1 M L2 T−3Every conservative force has a potential energy.", "By following two principles one can consistently assign a non-relative value to ''U'':* Wherever the force is zero, its potential energy is defined to be zero as well.", "* Whenever the force does work, potential energy is lost.===Generalized mechanics=== Quantity (common name/s) (Common) symbol/s Defining equation SI units DimensionGeneralized coordinates ''q, Q'' varies with choice varies with choiceGeneralized velocities varies with choice varies with choiceGeneralized momenta ''p, P'' varies with choice varies with choice Lagrangian ''L'' where and '''p''' = '''p'''(''t'') are vectors of the generalized coords and momenta, as functions of time J M L2 T−2 Hamiltonian ''H'' J M L2 T−2 Action, Hamilton's principal function ''S'', J s M L2 T−1" ], [ "Kinematics", "In the following rotational definitions, the angle can be any angle about the specified axis of rotation.", "It is customary to use ''θ'', but this does not have to be the polar angle used in polar coordinate systems.", "The unit axial vectordefines the axis of rotation, = unit vector in direction of , = unit vector tangential to the angle.", "Translation RotationVelocityAverage:Instantaneous:Angular velocityRotating rigid body:AccelerationAverage:Instantaneous:Angular accelerationRotating rigid body:JerkAverage:Instantaneous:Angular jerkRotating rigid body:" ], [ "Dynamics", " Translation RotationMomentumMomentum is the \"amount of translation\"For a rotating rigid body:Angular momentumAngular momentum is the \"amount of rotation\":and the cross-product is a pseudovector i.e.", "if '''r''' and '''p''' are reversed in direction (negative), '''L''' is not.In general '''I''' is an order-2 tensor, see above for its components.", "The dot '''·''' indicates tensor contraction.Force and Newton's 2nd lawResultant force acts on a system at the center of mass, equal to the rate of change of momentum:For a number of particles, the equation of motion for one particle ''i'' is:where '''p'''''i'' = momentum of particle ''i'', '''F'''''ij'' = force '''''on''''' particle ''i'' '''''by''''' particle ''j'', and '''F'''''E'' = resultant external force (due to any agent not part of system).", "Particle ''i'' does not exert a force on itself.TorqueTorque '''τ''' is also called moment of a force, because it is the rotational analogue to force:For rigid bodies, Newton's 2nd law for rotation takes the same form as for translation:Likewise, for a number of particles, the equation of motion for one particle ''i'' is:YankYank is rate of change of force:For constant mass, it becomes;RotatumRotatum '''Ρ''' is also called moment of a Yank, because it is the rotational analogue to yank:ImpulseImpulse is the change in momentum:For constant force '''F''':Twirl/angular impulse is the change in angular momentum:For constant torque '''τ''':=== Precession ===The precession angular speed of a spinning top is given by:where ''w'' is the weight of the spinning flywheel." ], [ "Energy", "The mechanical work done by an external agent on a system is equal to the change in kinetic energy of the system:=== General work-energy theorem (translation and rotation) ===The work done ''W'' by an external agent which exerts a force '''F''' (at '''r''') and torque '''τ''' on an object along a curved path ''C'' is:where θ is the angle of rotation about an axis defined by a unit vector '''n'''.=== Kinetic energy ===The change in kinetic energy for an object initially traveling at speed and later at speed is:=== Elastic potential energy ===For a stretched spring fixed at one end obeying Hooke's law, the elastic potential energy iswhere ''r''2 and ''r''1 are collinear coordinates of the free end of the spring, in the direction of the extension/compression, and k is the spring constant." ], [ "Euler's equations for rigid body dynamics", "Euler also worked out analogous laws of motion to those of Newton, see Euler's laws of motion.", "These extend the scope of Newton's laws to rigid bodies, but are essentially the same as above.", "A new equation Euler formulated is:where '''I''' is the moment of inertia tensor." ], [ "General planar motion", "The previous equations for planar motion can be used here: corollaries of momentum, angular momentum etc.", "can immediately follow by applying the above definitions.", "For any object moving in any path in a plane,the following general results apply to the particle.", "Kinematics Dynamics Position Velocity MomentumAngular momenta Acceleration The centripetal force iswhere again '''m''' is the mass moment, and the Coriolis force isThe Coriolis acceleration and force can also be written:=== Central force motion ===For a massive body moving in a central potential due to another object, which depends only on the radial separation between the centers of masses of the two objects, the equation of motion is:" ], [ "Equations of motion (constant acceleration)", "These equations can be used only when acceleration is constant.", "If acceleration is not constant then the general calculus equations above must be used, found by integrating the definitions of position, velocity and acceleration (see above).Linear motionAngular motion" ], [ "Galilean frame transforms", "For classical (Galileo-Newtonian) mechanics, the transformation law from one inertial or accelerating (including rotation) frame (reference frame traveling at constant velocity - including zero) to another is the Galilean transform.Unprimed quantities refer to position, velocity and acceleration in one frame F; primed quantities refer to position, velocity and acceleration in another frame F' moving at translational velocity '''V''' or angular velocity '''Ω''' relative to F. Conversely F moves at velocity (—'''V''' or —'''Ω''') relative to F'.", "The situation is similar for relative accelerations.", "Motion of entities Inertial frames Accelerating frames'''Translation''''''V''' = Constant relative velocity between two inertial frames F and F'.", "'''A''' = (Variable) relative acceleration between two accelerating frames F and F'.Relative positionRelative velocityEquivalent accelerationsRelative accelerationsApparent/fictitious forces'''Rotation''''''Ω''' = Constant relative angular velocity between two frames F and F'.", "'''Λ''' = (Variable) relative angular acceleration between two accelerating frames F and F'.Relative angular positionRelative velocityEquivalent accelerations Relative accelerationsApparent/fictitious torques Transformation of any vector '''T''' to a rotating frame" ], [ "Mechanical oscillators", "SHM, DHM, SHO, and DHO refer to simple harmonic motion, damped harmonic motion, simple harmonic oscillator and damped harmonic oscillator respectively.+ Equations of motion Physical situation Nomenclature Translational equations Angular equations SHM * ''x'' = Transverse displacement* ''θ'' = Angular displacement* ''A'' = Transverse amplitude* Θ = Angular amplitude Solution: Solution: Unforced DHM * ''b'' = damping constant* ''κ'' = torsion constant Solution (see below for ''ω'''):Resonant frequency:Damping rate:Expected lifetime of excitation: Solution:Resonant frequency:Damping rate:Expected lifetime of excitation:+ Angular frequencies Physical situation Nomenclature Equations Linear undamped unforced SHO * ''k'' = spring constant* ''m'' = mass of oscillating bob Linear unforced DHO * ''k'' = spring constant* ''b'' = Damping coefficient Low amplitude angular SHO * ''I'' = Moment of inertia about oscillating axis* ''κ'' = torsion constant Low amplitude simple pendulum * ''L'' = Length of pendulum* ''g'' = Gravitational acceleration* Θ = Angular amplitude Approximate valueExact value can be shown to be:+ Energy in mechanical oscillations Physical situation Nomenclature Equations SHM energy * ''T'' = kinetic energy* ''U'' = potential energy* ''E'' = total energy Potential energyMaximum value at ''x'' = ''A'':Kinetic energyTotal energy DHM energy" ], [ "See also", "*List of physics formulae*Defining equation (physical chemistry)*Constitutive equation*Mechanics*Optics*Electromagnetism*Thermodynamics*Acoustics*Isaac Newton*List of equations in wave theory*List of relativistic equations*List of equations in fluid mechanics*List of equations in gravitation*List of electromagnetism equations*List of photonics equations*List of equations in quantum mechanics*List of equations in nuclear and particle physics" ], [ "Notes" ], [ "References", "***" ] ]
wikipedia
[ [ "Cursus honorum" ], [ "Introduction", "The , or more colloquially 'ladder of offices'; ) was the sequential order of public offices held by aspiring politicians in the Roman Republic and the early Roman Empire.", "It was designed for men of senatorial rank.", "The ''cursus honorum'' comprised a mixture of military and political administration posts; the ultimate prize for winning election to each \"rung\" in the sequence was to become one of the two consuls in a given year.These rules were altered and flagrantly ignored in the course of the last century of the Republic.", "For example, Gaius Marius held consulships for five years in a row between 104 BC and 100 BC.", "He was consul seven times in all, also serving in 107 and 86.Officially presented as opportunities for public service, the offices often became mere opportunities for self-aggrandizement.", "The constitutional reforms of Sulla between 82 and 79 BC required a ten-year interval before holding the same office again for another term.To have held each office at the youngest possible age (''suo anno'', 'in his year') was considered a great political success.", "For instance, to miss out on a praetorship at 39 meant that one could not become consul at 42.Cicero expressed extreme pride not only in being a ''novus homo'' ('new man'; comparable to a \"self-made man\") who became consul even though none of his ancestors had ever served as a consul, but also in having become consul \"in his year\".The Roman ''cursus honorum''" ], [ "Military service", "Prior to entering political life and the ''cursus honorum'', a young man of senatorial rank was expected to serve around ten years of military duty.", "The years of service were intended to be mandatory in order to qualify for political office.Advancement and honors would improve his political prospects, and a successful military career might culminate in the office of military tribune, to which 24 men were elected by the Tribal Assembly each year.", "The rank of military tribune is sometimes described as the first office of the ''cursus honorum''." ], [ "Quaestor", "The first official post was that of quaestor.", "Ever since the reforms of Sulla, candidates had to be at least 30 years old to hold the office.", "From the time of Augustus onwards, twenty quaestors served in the financial administration at Rome or as second-in-command to a governor in the provinces.", "They could also serve as the paymaster for a legion." ], [ "Aedile", "At 36 years of age, a promagistrate could stand for election to one of the aediles (pronounced , from ''aedes'', \"temple edifice\") positions.", "Of these aediles, two were plebeian and two were patrician, with the patrician aediles called curule aediles.", "The plebeian aediles were elected by the Plebeian Council and the curule aediles were either elected by the Tribal Assembly or appointed by the reigning consul.", "The aediles had administrative responsibilities in Rome.", "They had to take care of the temples (whence their title, from the Latin ''aedes'', \"temple\"), organize games, and be responsible for the maintenance of the public buildings in Rome.", "Moreover, they took charge of Rome's water and food supplies; in their capacity as market superintendents, they served sometimes as judges in mercantile affairs.The aedile was the supervisor of public works; the words \"edifice\" and \"edification\" stem from the same root.", "He oversaw the public works, temples and markets.", "Therefore, the aediles would have been in some cooperation with the current censors, who had similar or related duties.", "Also, they oversaw the organization of festivals and games (''ludi''), which made this a very sought-after office for a career minded politician of the late Republic, as it was a good means of gaining popularity by staging spectacles.", "''Cursus honorum'' as during Julius Caesar's career (1st century BC)Curule aediles were added at a later date in the 4th century BC; their duties do not differ substantially from plebeian aediles.", "However, unlike plebeian aediles, curule aediles were allowed certain symbols of rank—the ''sella curulis'' or curule chair, for example—and only patricians could stand for election to curule aedile.", "This later changed, and both plebeians and patricians could stand for curule aedileship.The elections for curule aedile were at first alternated between patricians and plebeians, until late in the 2nd century BC, when the practice was abandoned and both classes became free to run during all years.While part of the ''cursus honorum'', this step was optional and not required to hold future offices.", "Though the office was usually held after the quaestorship and before the praetorship, there are some cases with former praetors serving as aediles." ], [ "Praetor", "After serving either as quaestor or as aedile, a man of 39 years could run for praetor.", "During the reign of Augustus this requirement was lowered to 30, at the request of Gaius Maecenas.", "The number of praetors elected varied through history, generally increasing with time.", "During the republic, six or eight were generally elected each year to serve judicial functions throughout Rome and other governmental responsibilities.", "In the absence of the consuls, a praetor would be given command of the garrison in Rome or in Italy.", "Also, a praetor could exercise the functions of the consuls throughout Rome, but their main function was that of a judge.", "They would preside over trials involving criminal acts, grant court orders and validate \"illegal\" acts as acts of administering justice.", "A praetor was escorted by six lictors, and wielded ''imperium''.", "After a term as praetor, the magistrate could serve as a provincial governor with the title of propraetor, wielding ''propraetor imperium'', commanding the province's legions, and possessing ultimate authority within his province(s).Two of the praetors were more prestigious than the others.", "The first was the Praetor Peregrinus, who was the chief judge in trials involving one or more foreigners.", "The other was the Praetor Urbanus, the chief judicial office in Rome.", "He had the power to overturn any verdict by any other courts, and served as judge in cases involving criminal charges against provincial governors.", "The Praetor Urbanus was not allowed to leave the city for more than ten days.", "If one of these two praetors was absent from Rome, the other would perform the duties of both." ], [ "Consul", "The office of consul was the most prestigious of all of the offices on the ''cursus honorum'', and represented the summit of a successful career.", "The minimum age was 42.Years were identified by the names of the two consuls elected for a particular year; for instance, ''M.", "Messalla et M. Pisone consulibus'', \"in the consulship of Messalla and Piso\", dates an event to 61 BC.", "Consuls were responsible for the city's political agenda, commanded large-scale armies and controlled important provinces.", "The consuls served for only a year (a restriction intended to limit the amassing of power by individuals) and could only rule when they agreed, because each consul could veto the other's decision.The consuls would alternate monthly as the chairman of the Senate.", "They also were the supreme commanders in the Roman army, with each being granted two legions during their consular year.", "Consuls also exercised the highest juridical power in the Republic, being the only office with the power to override the decisions of the Praetor Urbanus.", "Only laws and the decrees of the Senate or the People's assembly limited their powers, and only the veto of a fellow consul or a tribune of the plebs could supersede their decisions.A consul was escorted by twelve lictors, held ''imperium'' and wore the toga ''praetexta''.", "Because the consul was the highest executive office within the Republic, they had the power to veto any action or proposal by any other magistrate, save that of the Tribune of the Plebs.", "After a consulship, a consul was assigned one of the more important provinces and acted as the governor in the same way that a propraetor did, only owning proconsular ''imperium''.", "A second consulship could only be attempted after an interval of 10 years to prevent one man holding too much power." ], [ "Governor", "Although not part of the ''cursus honorum'', upon completing a term as either praetor or consul, an officer was required to serve a term as propraetor and proconsul, respectively, in one of Rome's many provinces.", "These propraetors and proconsuls held near autocratic authority within their selected province or provinces.", "Because each governor held equal ''imperium'' to the equivalent magistrate, they were escorted by the same number of lictors (12) and could only be vetoed by a reigning consul or praetor.", "Their abilities to govern were only limited by the decrees of the Senate or the people's assemblies, and the Tribune of the Plebs was unable to veto their acts as long as the governor remained at least a mile outside of Rome." ], [ "Censor", "After a term as consul, the final step in the ''cursus honorum'' was the office of ''censor''.", "This was the only office in the Roman Republic whose term was a period of eighteen months instead of the usual twelve.", "Censors were elected every five years and although the office held no military ''imperium'', it was considered a great honour.", "The censors took a regular census of the people and then apportioned the citizens into voting classes on the basis of income and tribal affiliation.", "The censors enrolled new citizens in tribes and voting classes as well.", "The censors were also in charge of the membership roll of the Senate, every five years adding new senators who had been elected to the requisite offices.", "Censors could also remove unworthy members from the Senate.", "This ability was lost during the dictatorship of Sulla.", "Censors were also responsible for construction of public buildings and the moral status of the city.Censors also had financial duties, in that they had to put out to tender projects that were to be financed by the state.", "Also, the censors were in charge of the leasing out of conquered land for public use and auction.", "Though this office owned no ''imperium'', meaning no lictors for protection, they were allowed to wear the toga ''praetexta''." ], [ "Tribune of the Plebs", "The office of Tribune of the Plebs was an important step in the political career of plebeians.", "Patricians could not hold the office.", "They were not an official step in the ''cursus honorum''.", "The Tribune was an office first created to protect the right of the common man in Roman politics and served as the head of the Plebeian Council.", "In the mid-to-late Republic, however, plebeians were often just as, and sometimes more, wealthy and powerful than patricians.", "Those who held the office were granted sacrosanctity (the right to be legally protected from any physical harm), the power to rescue any plebeian from the hands of a patrician magistrate, and the right to veto any act or proposal of any magistrate, including another tribune of the people and the consuls.", "The tribune also had the power to exercise capital punishment against any person who interfered in the performance of his duties.", "The tribunes could even convene a Senate meeting and lay legislation before it and arrest magistrates.", "Their houses had to remain open for visitors even during the night, and they were not allowed to be more than a day's journey from Rome.", "Due to their unique power of sacrosanctity, the Tribune had no need for lictors for protection and owned no ''imperium'', nor could they wear the toga ''praetexta''.", "For a period after Sulla's reforms, a person who had held the office of Tribune of the Plebs could no longer qualify for any other office, and the powers of the tribunes were more limited, but these restrictions were subsequently lifted." ], [ "''Princeps senatus''", "Another office not officially a step in the ''cursus honorum'' was the ''princeps senatus'', an extremely prestigious office for a patrician.", "The ''princeps senatus'' served as the leader of the Senate and was chosen to serve a five-year term by each pair of Censors every five years.", "Censors could, however, confirm a ''princeps senatus'' for a period of another five years.", "The ''princeps senatus'' was chosen from all Patricians who had served as a Consul, with former Censors usually holding the office.", "The office originally granted the holder the ability to speak first at session on the topic presented by the presiding magistrate, but eventually gained the power to open and close the senate sessions, decide the agenda, decide where the session should take place, impose order and other rules of the session, meet in the name of the senate with embassies of foreign countries, and write in the name of the senate letters and dispatches.", "This office, like the Tribune, did not own ''imperium'', was not escorted by lictors, and could not wear the ''toga praetexta''." ], [ "Dictator and ''magister equitum''", "Of all the offices within the Roman Republic, none granted as much power and authority as the position of dictator, known as the Master of the People.", "In times of emergency, the Senate would declare that a dictator was required, and the current consuls would appoint a dictator.", "This was the only decision that could not be vetoed by the Tribune of the Plebs.", "The dictator was the sole exception to the Roman legal principles of having multiple magistrates in the same office and being legally able to be held to answer for actions in office.", "Essentially by definition, only one dictator could serve at a time, and no dictator could ever be held legally responsible for any action during his time in office for any reason.The dictator was the highest magistrate in degree of ''imperium'' and was attended by twenty-four lictors (as were the former Kings of Rome).", "Although his term lasted only six months instead of twelve (except for the Dictatorships of Sulla and Caesar), all other magistrates reported to the dictator (except for the tribunes of the plebs – although they could not veto any of the dictator's acts), granting the dictator absolute authority in both civil and military matters throughout the Republic.", "The dictator was free from the control of the Senate in all that he did, could execute anyone without a trial for any reason, and could ignore any law in the performance of his duties.", "The dictator was the sole magistrate under the Republic that was truly independent in discharging his duties.", "All of the other offices were extensions of the Senate's executive authority and thus answerable to the Senate.", "Since the dictator exercised his own authority, he did not suffer this limitation, which was the cornerstone of the office's power.When a dictator entered office, he appointed to serve as his second-in-command a ''magister equitum'', the Master of the Horse, whose office ceased to exist once the dictator left office.", "The ''magister equitum'' held ''praetorian imperium'', was attended by six lictors, and was charged with assisting the dictator in managing the State.", "When the dictator was away from Rome, the ''magister equitum'' usually remained behind to administer the city.", "The ''magister equitum'', like the dictator, had unchallengeable authority in all civil and military affairs, with his decisions only being overturned by the dictator himself.The dictatorship was definitively abolished in 44 BC after the assassination of Gaius Julius Caesar (''Lex Antonia'')." ], [ "See also", "* Outline of ancient Rome – overview of and topical guide to ancient Rome* Political institutions of ancient Rome – lists of political institutions of ancient Rome* Roman Senate – political institution in ancient Rome* ''Vigintisexviri'' – college of minor magistrates of the Roman Republic* ''Tres militiae'' – the equestrian order version of the ''cursus honorum''" ], [ "References" ], [ "External links", "* Diagram of the ''cursus honorum'' * Livius.org: Cursus honorum" ] ]
wikipedia
[ [ "Continental drift" ], [ "Introduction", "'''Continental drift''' is the hypothesis, originating in the early 20th century, that Earth's continents move or drift relative to each other over geologic time.", "The hypothesis of continental drift has since been validated and incorporated into the science of plate tectonics, which studies the movement of the continents as they ride on plates of the Earth's lithosphere.The speculation that continents might have \"drifted\" was first put forward by Abraham Ortelius in 1596.A pioneer of the modern view of mobilism was the Austrian geologist Otto Ampferer.", "The concept was independently and more fully developed by Alfred Wegener in his 1915 publication, \"The Origin of Continents and Oceans\".", "However, at that time the hypothesis was rejected by many for lack of any motive mechanism.", "The English geologist Arthur Holmes later proposed mantle convection for that mechanism." ], [ "History", "=== Early history ===Abraham Ortelius by Peter Paul Rubens, 1633Abraham Ortelius , Theodor Christoph Lilienthal (1756), Alexander von Humboldt (1801 and 1845), Antonio Snider-Pellegrini , and others had noted earlier that the shapes of continents on opposite sides of the Atlantic Ocean (most notably, Africa and South America) seem to fit together.", "W. J. Kious described Ortelius' thoughts in this way:In 1889, Alfred Russel Wallace remarked, \"It was formerly a very general belief, even amongst geologists, that the great features of the earth's surface, no less than the smaller ones, were subject to continual mutations, and that during the course of known geological time the continents and great oceans had, again and again, changed places with each other.\"", "He quotes Charles Lyell as saying, \"Continents, therefore, although permanent for whole geological epochs, shift their positions entirely in the course of ages.\"", "and claims that the first to throw doubt on this was James Dwight Dana in 1849.Antonio Snider-Pellegrini's Illustration of the closed and opened Atlantic Ocean (1858)In his ''Manual of Geology'' (1863), Dana wrote, \"The continents and oceans had their general outline or form defined in earliest time.", "This has been proved with regard to North America from the position and distribution of the first beds of the Lower Silurian, – those of the Potsdam epoch.", "The facts indicate that the continent of North America had its surface near tide-level, part above and part below it (p.196); and this will probably be proved to be the condition in Primordial time of the other continents also.", "And, if the outlines of the continents were marked out, it follows that the outlines of the oceans were no less so\".", "Dana was enormously influential in America—his ''Manual of Mineralogy'' is still in print in revised form—and the theory became known as the ''Permanence theory''.This appeared to be confirmed by the exploration of the deep sea beds conducted by the ''Challenger'' expedition, 1872–1876, which showed that contrary to expectation, land debris brought down by rivers to the ocean is deposited comparatively close to the shore on what is now known as the continental shelf.", "This suggested that the oceans were a permanent feature of the Earth's surface, rather than them having \"changed places\" with the continents.Eduard Suess had proposed a supercontinent Gondwana in 1885 and the Tethys Ocean in 1893, assuming a land-bridge between the present continents submerged in the form of a geosyncline, and John Perry had written an 1895 paper proposing that the Earth's interior was fluid, and disagreeing with Lord Kelvin on the age of the Earth.=== Wegener and his predecessors ===Alfred WegenerApart from the earlier speculations mentioned above, the idea that the American continents had once formed a single landmass with Eurasia and Africa was postulated by several scientists before Alfred Wegener's 1912 paper.", "Although Wegener's theory was formed independently and was more complete than those of his predecessors, Wegener later credited a number of past authors with similar ideas: Franklin Coxworthy (between 1848 and 1890), Roberto Mantovani (between 1889 and 1909), William Henry Pickering (1907) and Frank Bursley Taylor (1908).The similarity of southern continent geological formations had led Roberto Mantovani to conjecture in 1889 and 1909 that all the continents had once been joined into a supercontinent; Wegener noted the similarity of Mantovani's and his own maps of the former positions of the southern continents.", "In Mantovani's conjecture, this continent broke due to volcanic activity caused by thermal expansion, and the new continents drifted away from each other because of further expansion of the rip-zones, where the oceans now lie.", "This led Mantovani to propose a now-discredited Expanding Earth theory.Continental drift without expansion was proposed by Frank Bursley Taylor, who suggested in 1908 (published in 1910) that the continents were moved into their present positions by a process of \"continental creep\", later proposing a mechanism of increased tidal forces during the Cretaceous dragging the crust towards the equator.", "He was the first to realize that one of the effects of continental motion would be the formation of mountains, attributing the formation of the Himalayas to the collision between the Indian subcontinent with Asia.", "Wegener said that of all those theories, Taylor's had the most similarities to his own.", "For a time in the mid-20th century, the theory of continental drift was referred to as the \"Taylor-Wegener hypothesis\".Alfred Wegener first presented his hypothesis to the German Geological Society on 6 January 1912.His hypothesis was that the continents had once formed a single landmass, called Pangaea, before breaking apart and drifting to their present locations.Wegener was the first to use the phrase \"continental drift\" (1912, 1915) (in German \"die Verschiebung der Kontinente\" – translated into English in 1922) and formally publish the hypothesis that the continents had somehow \"drifted\" apart.", "Although he presented much evidence for continental drift, he was unable to provide a convincing explanation for the physical processes which might have caused this drift.", "He suggested that the continents had been pulled apart by the centrifugal pseudoforce (''Polflucht'') of the Earth's rotation or by a small component of astronomical precession, but calculations showed that the force was not sufficient.", "The Polflucht hypothesis was also studied by Paul Sophus Epstein in 1920 and found to be implausible.=== Rejection of Wegener's theory, 1910s–1950s ===Although now accepted, the theory of continental drift was rejected for many years, with evidence in its favor considered insufficient.", "One problem was that a plausible driving force was missing.", "A second problem was that Wegener's estimate of the speed of continental motion, 250 cm/year, was implausibly high.", "(The currently accepted rate for the separation of the Americas from Europe and Africa is about 2.5 cm/year).", "Furthermore, Wegener was treated less seriously because he was not a geologist.", "Even today, the details of the forces propelling the plates are poorly understood.The English geologist Arthur Holmes championed the theory of continental drift at a time when it was deeply unfashionable.", "He proposed in 1931 that the Earth's mantle contained convection cells which dissipated heat produced by radioactive decay and moved the crust at the surface.", "His ''Principles of Physical Geology'', ending with a chapter on continental drift, was published in 1944.Geological maps of the time showed huge land bridges spanning the Atlantic and Indian oceans to account for the similarities of fauna and flora and the divisions of the Asian continent in the Permian period, but failing to account for glaciation in India, Australia and South Africa.====The fixists====Hans Stille and Leopold Kober opposed the idea of continental drift and worked on a \"fixist\" geosyncline model with Earth contraction playing a key role in the formation of orogens.", "Other geologists who opposed continental drift were Bailey Willis, Charles Schuchert, Rollin Chamberlin, Walther Bucher and Walther Penck.", "In 1939 an international geological conference was held in Frankfurt.", "This conference came to be dominated by the fixists, especially as those geologists specializing in tectonics were all fixists except Willem van der Gracht.", "Criticism of continental drift and mobilism was abundant at the conference not only from tectonicists but also from sedimentological (Nölke), paleontological (Nölke), mechanical (Lehmann) and oceanographic (Troll, Wüst) perspectives.", "Hans Cloos, the organizer of the conference, was also a fixist who together with Troll held the view that excepting the Pacific Ocean continents were not radically different from oceans in their behaviour.", "The mobilist theory of Émile Argand for the Alpine orogeny was criticized by Kurt Leuchs.", "The few drifters and mobilists at the conference appealed to biogeography (Kirsch, Wittmann), paleoclimatology (Wegener, K), paleontology (Gerth) and geodetic measurements (Wegener, K).", "F. Bernauer correctly equated Reykjanes in south-west Iceland with the Mid-Atlantic Ridge, arguing with this that the floor of the Atlantic Ocean was undergoing extension just like Reykjanes.", "Bernauer thought this extension had drifted the continents only 100–200 km apart, the approximate width of the volcanic zone in Iceland.David Attenborough, who attended university in the second half of the 1940s, recounted an incident illustrating its lack of acceptance then: \"I once asked one of my lecturers why he was not talking to us about continental drift and I was told, sneeringly, that if I could prove there was a force that could move continents, then he might think about it.", "The idea was moonshine, I was informed.", "\"As late as 1953—just five years before Carey introduced the theory of plate tectonics—the theory of continental drift was rejected by the physicist Scheidegger on the following grounds.", "* First, it had been shown that floating masses on a rotating geoid would collect at the equator, and stay there.", "This would explain one, but only one, mountain building episode between any pair of continents; it failed to account for earlier orogenic episodes.", "* Second, masses floating freely in a fluid substratum, like icebergs in the ocean, should be in isostatic equilibrium (in which the forces of gravity and buoyancy are in balance).", "But gravitational measurements showed that many areas are not in isostatic equilibrium.", "* Third, there was the problem of why some parts of the Earth's surface (crust) should have solidified while other parts were still fluid.", "Various attempts to explain this foundered on other difficulties.=== Road to acceptance ===From the 1930s to the late 1950s, works by Vening-Meinesz, Holmes, Umbgrove, and numerous others outlined concepts that were close or nearly identical to modern plate tectonics theory.", "In particular, the English geologist Arthur Holmes proposed in 1920 that plate junctions might lie beneath the sea, and in 1928 that convection currents within the mantle might be the driving force.", "Holmes' views were particularly influential: in his bestselling textbook, ''Principles of Physical Geology,'' he included a chapter on continental drift, proposing that Earth's mantle contained convection cells which dissipated radioactive heat and moved the crust at the surface.", "Holmes' proposal resolved the phase disequilibrium objection (the underlying fluid was kept from solidifying by radioactive heating from the core).", "However, scientific communication in the 1930s and 1940s was inhibited by World War II, and the theory still required work to avoid foundering on the orogeny and isostasy objections.", "Worse, the most viable forms of the theory predicted the existence of convection cell boundaries reaching deep into the Earth, that had yet to be observed.Fossil patterns across continents (Gondwanaland) In 1947, a team of scientists led by Maurice Ewing confirmed the existence of a rise in the central Atlantic Ocean, and found that the floor of the seabed beneath the sediments was chemically and physically different from continental crust.", "As oceanographers continued to bathymeter the ocean basins, a system of mid-oceanic ridges was detected.", "An important conclusion was that along this system, new ocean floor was being created, which led to the concept of the \"Great Global Rift\".Meanwhile, scientists began recognizing odd magnetic variations across the ocean floor using devices developed during World War II to detect submarines.", "Over the next decade, it became increasingly clear that the magnetization patterns were not anomalies, as had been originally supposed.", "In a series of papers in 1959–1963, Heezen, Dietz, Hess, Mason, Vine, Matthews, and Morley collectively realized that the magnetization of the ocean floor formed extensive, zebra-like patterns: one stripe would exhibit normal polarity and the adjoining stripes reversed polarity.", "The best explanation was the \"conveyor belt\" or Vine–Matthews–Morley hypothesis.", "New magma from deep within the Earth rises easily through these weak zones and eventually erupts along the crest of the ridges to create new oceanic crust.", "The new crust is magnetized by the Earth's magnetic field, which undergoes occasional reversals.", "Formation of new crust then displaces the magnetized crust apart, akin to a conveyor belt – hence the name.Without workable alternatives to explain the stripes, geophysicists were forced to conclude that Holmes had been right: ocean rifts were sites of perpetual orogeny at the boundaries of convection cells.", "By 1967, barely two decades after discovery of the mid-oceanic rifts, and a decade after discovery of the striping, plate tectonics had become axiomatic to modern geophysics.In addition, Marie Tharp, in collaboration with Bruce Heezen, who was initially sceptical of Tharp's observations that her maps confirmed continental drift theory, provided essential corroboration, using her skills in cartography and seismographic data, to confirm the theory.====Modern evidence====Geophysicist Jack Oliver is credited with providing seismologic evidence supporting plate tectonics which encompassed and superseded continental drift with the article \"Seismology and the New Global Tectonics\", published in 1968, using data collected from seismologic stations, including those he set up in the South Pacific.", "The modern theory of plate tectonics, refining Wegener, explains that there are two kinds of crust of different composition: continental crust and oceanic crust, both floating above a much deeper \"plastic\" mantle.", "Continental crust is inherently lighter.", "Oceanic crust is created at spreading centers, and this, along with subduction, drives the system of plates in a chaotic manner, resulting in continuous orogeny and areas of isostatic imbalance.Evidence for the movement of continents on tectonic plates is now extensive.", "Similar plant and animal fossils are found around the shores of different continents, suggesting that they were once joined.", "The fossils of ''Mesosaurus'', a freshwater reptile rather like a small crocodile, found both in Brazil and South Africa, are one example; another is the discovery of fossils of the land reptile ''Lystrosaurus'' in rocks of the same age at locations in Africa, India, and Antarctica.", "There is also living evidence, with the same animals being found on two continents.", "Some earthworm families (such as Ocnerodrilidae, Acanthodrilidae, Octochaetidae) are found in South America and Africa.", "''Mesosaurus'' skeleton, MacGregor, 1908The complementary arrangement of the facing sides of South America and Africa is obvious but a temporary coincidence.", "In millions of years, slab pull, ridge-push, and other forces of tectonophysics will further separate and rotate those two continents.", "It was that temporary feature that inspired Wegener to study what he defined as continental drift although he did not live to see his hypothesis generally accepted.The widespread distribution of Permo-Carboniferous glacial sediments in South America, Africa, Madagascar, Arabia, India, Antarctica and Australia was one of the major pieces of evidence for the theory of continental drift.", "The continuity of glaciers, inferred from oriented glacial striations and deposits called tillites, suggested the existence of the supercontinent of Gondwana, which became a central element of the concept of continental drift.", "Striations indicated glacial flow away from the equator and toward the poles, based on continents' current positions and orientations, and supported the idea that the southern continents had previously been in dramatically different locations that were contiguous with one another." ], [ "See also", "* * Israel C. White" ], [ "Citations" ], [ "General and cited sources", "* * * (pb: )* * (First edition published 1570, 1587 edition online)* * ." ], [ "External links", "* Benjamin Franklin (1782) and Ralph Waldo Emerson (1834) noted Continental Drift* A brief introduction to Plate Tectonics, based on the work of Alfred Wegener* Animation of continental drift for last 1 billion years* Maps of continental drift, from the Precambrian to the future* 3D visualization of what did Earth look like from  750 million years ago to present (at present location of your choice)" ] ]
wikipedia
[ [ "Commodores" ], [ "Introduction", "'''Commodores''', often billed as '''the Commodores''', are an American funk and soul group.", "The group's most successful period was in the late 1970s and early 1980s when Lionel Richie was the co-lead singer.The members of the group met as mostly freshmen at Tuskegee Institute (now Tuskegee University) in 1968, and signed with Motown in November 1972, having first caught the public eye opening for the Jackson 5 while on tour.The band's biggest hit singles are ballads such as \"Easy\", \"Three Times a Lady\", and \"Nightshift\"; and funk-influenced dance songs, including \"Brick House\", \"Fancy Dancer\", \"Lady (You Bring Me Up)\", and \"Too Hot ta Trot\".", "Commodores were inducted into the Alabama Music Hall of Fame and Vocal Group Hall of Fame.", "The band has also won one Grammy Award out of nine nominations.", "The Commodores have sold over 70 million albums worldwide." ], [ "History", "Commodores were formed from two former student groups, the Mystics and the Jays.", "Richie described some members of the Mystics as \"jazz buffs\".", "The new six-man band featured Lionel Richie, Thomas McClary, and William King from the Mystics, and Andre Callahan, Michael Gilbert, and Milan Williams from the Jays.", "To choose their name, William King opened a dictionary and randomly picked a word.", "\"We lucked in,\" he remarked with a laugh when telling this story to ''People'' magazine.", "\"We almost became 'The Commodes.", "'\"The bandmembers attended Tuskegee University in Alabama.", "After winning the university's annual freshman talent contest, they played at fraternity parties as well as a weekend gig at the Black Forest Inn, one of a few clubs in Tuskegee that catered to college students.", "They performed cover tunes and some original songs with their first singer, James Ingram (not the famous solo artist).", "Ingram, older than the rest of the band, left to serve in Vietnam, and was later replaced by drummer Walter \"Clyde\" Orange, who wrote or co-wrote many of their hits.", "Lionel Richie and Orange alternated as lead singers.", "Orange was the lead singer on the Top 10 hits \"Brick House\" (1977) and \"Nightshift\" (1985).The early band was managed by Benny Ashburn, who brought them to his family's vacation lodge on Martha's Vineyard in 1971 and 1972.There, Ashburn test-marketed the group by having them play in parking lots and summer festivals.", "\"Machine Gun\" (1974), the instrumental title track from the band's debut album, became a staple at American sporting events, and is also heard in many films, including ''Boogie Nights'' and ''Looking for Mr. Goodbar''.", "It reached No.", "22 on the ''Billboard'' Hot 100 in 1974.Another 1974 song \"I Feel Sanctified\" has been called a \"prototype\" of Wild Cherry's 1976 big hit \"Play That Funky Music\".", "Three albums released in 1975 and 1976, ''Caught in the Act'' was funk album, but ''Movin' On'' and ''Hot on the Tracks'' were pop albums.", "After those recordings the group developed the mellower sound hinted at in their 1976 top-ten hits, \"Sweet Love\" and \"Just to Be Close to You\".", "In 1977, the Commodores released \"Easy\", which became the group's biggest hit yet, reaching No.", "4 in the US, followed by funky single \"Brick House\", also top 5, both from their album ''Commodores'', as was \"Zoom\".", "The group reached No.", "1 in 1978 with \"Three Times a Lady\".", "In 1979, the Commodores scored another top-five ballad, \"Sail On\", before reaching the top of the charts once again with another ballad, \"Still\".", "In 1981 they released two top-ten hits with \"Oh No\" (No.", "4) and their first upbeat single in almost five years, \"Lady (You Bring Me Up)\" (No.", "8).Commodores made a brief appearance in the 1978 film, ''Thank God It's Friday''.", "They performed the song \"Too Hot ta Trot\" during the dance contest; the songs \"Brick House\" and \"Easy\" were also played in the movieIn 1982, the group decided to take a hiatus from touring and recording, during which time Lionel Richie recorded a solo album at the suggestion of Motown and the other group members.", "Its success encouraged Richie to pursue a solo career, and Skyler Jett replaced him as co-lead singer.", "Also in 1982, Ashburn died of a heart attack at the age of 54.Band performance in Florida during the 1990sFounding member McClary left in 1984 (shortly after Richie) to pursue a solo career, and to develop a gospel music company.", "McClary was replaced by guitarist-vocalist Sheldon Reynolds.", "Then LaPread left in 1986 and moved to Auckland, New Zealand.", "Reynolds departed for Earth, Wind & Fire in 1987, which prompted trumpeter William \"WAK\" King to take over primary guitar duties for live performances.", "Keyboardist Milan Williams exited the band in 1989 after allegedly refusing to tour South Africa.The group gradually abandoned its funk roots and moved into the more commercial pop arena.", "In 1984, former Heatwave singer James Dean \"J.D.\"", "Nicholas assumed co-lead vocal duties with drummer Walter Orange.", "That line-up was hitless until 1985 when their final Motown album ''Nightshift'', produced by Dennis Lambert (prior albums were produced by James Anthony Carmichael), delivered the title track \"Nightshift\", a loving tribute to Marvin Gaye and Jackie Wilson, both of whom had died the previous year.", "\"Nightshift\" hit no.", "3 in the US and won the Commodores their first Grammy for Best R&B Performance by a Duo or Group With Vocals in 1985.In 2010 a new version was recorded, dedicated to Michael Jackson.", "The Commodores were on a European tour performing at Wembley Arena, London, on June 25, 2009, when they walked off the stage after they were told that Michael Jackson had died.", "Initially the band thought it was a hoax.", "However, back in their dressing rooms they received confirmation and broke down in tears.", "The next night at Birmingham's NIA Arena, J.D.", "Nicholas added Jackson's name to the lyrics of the song, and henceforth the Commodores have mentioned Jackson and other deceased R&B singers.", "Thus came the inspiration upon the one-year anniversary of Jackson's death to re-record, with new lyrics, the hit song \"Nightshift\" as a tribute.Commodores performing at the 25th Natchitoches Jazz and R&B Festival in 2022In 1990, they formed Commodores Records and re-recorded their 20 greatest hits as ''Commodores Hits Vol.", "I & II''.", "They have recorded a live album, ''Commodores Live'', along with a DVD of the same name, and a Christmas album titled ''Commodores Christmas''.", "In 2012, the band was working on new material, with some contributions written by current and former members.Commodores as of 2020 consist of Walter \"Clyde\" Orange, James Dean \"J.D.\"", "Nicholas, and William \"WAK\" King, along with their five-piece band The Mean Machine.They continue to perform, playing at arenas, theaters, and festivals around the world." ], [ "Personnel", "===Current members===* William \"WAK\" King – trumpet, guitar, keyboards, vocals (1968–present)* Walter Orange – vocals, drums (1972–present)* James Dean \"J.D.\"", "Nicholas – vocals (1984–present)===Former members===* Lionel Richie – vocals, keyboards, saxophone (1968–82)* Milan Williams – keyboards, rhythm guitar (1968–89)* Thomas McClary – lead guitar, vocals (1968–83)* Andre Callahan – drums, vocals, keyboards (1968–70)* Michael Gilbert – bass guitar, trumpet (1968–70) * Eugene Ward – keyboards (1968–70)* Ronald LaPread – bass guitar (1970–86)* James Ingram – vocals, drums (1970–72)* Skyler Jett – vocals (1982–84)* Sheldon Reynolds – lead guitar (1983–87)* Mikael Manley – lead guitar (1995–2005)====Timeline====" ], [ "Discography", ";Studio albums* ''Machine Gun'' (1974)* ''Caught in the Act'' (1975)* ''Movin' On'' (1975)* ''Hot on the Tracks'' (1976)* ''Commodores'' (1977)* ''Natural High'' (1978)* ''Midnight Magic'' (1979)* ''Heroes'' (1980)* ''In the Pocket'' (1981)* ''Commodores 13'' (1983)* ''Nightshift'' (1985)* ''United'' (1986)* ''Rock Solid'' (1988)* ''No Tricks'' (1993)" ], [ "Accolades", "===Grammy awards===The Commodores have won one Grammy Award out of ten nominations.+Grammy Awards Year Category Work Result 1978Best Rhythm & Blues Vocal Performance – Duo, Group Or Chorus \"Easy\" \"Brick House\" 1979 \"Natural High\" Best Pop Vocal Performance by a Duo or Group \"Three Times A Lady\" 1980 \"Sail On\" Best Rhythm & Blues Vocal Performance – Duo, Group Or Chorus \"Midnight Magic\" 1981 \"Heroes\" Best Inspirational Performance \"Jesus Is Love\" 1982Best Rhythm & Blues Vocal Performance – Duo, Group Or Chorus \"Lady (You Bring Me Up)\" 1986 \"Nightshift\" ===Alabama Music Hall of Fame===During 1995 the Commodores were inducted into the Alabama Music Hall of Fame.===Vocal Group Hall of Fame===During 2003 the Commodores were also inducted into the Vocal Group Hall of Fame." ], [ "References" ], [ "External links", "** Lionel Richie interview by Pete Lewis, 'Blues & Soul' 03/2009* 'The Commodores' Vocal Group Hall of Fame Page" ] ]
wikipedia
[ [ "Collagen" ], [ "Introduction", "Tropocollagen molecule: three left-handed procollagens (red, green, blue) join to form a right-handed triple helical tropocollagen.", "'''Collagen''' () is the main structural protein in the extracellular matrix found in the body's various connective tissues.", "As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole-body protein content.", "Collagen consists of amino acids bound together to form a triple helix of elongated fibril known as a collagen helix.", "It is mostly found in connective tissue such as cartilage, bones, tendons, ligaments, and skin.", "Vitamin C is vital for collagen synthesis, and Vitamin E improves the production of collagen.FISH visualization of collagen expression in ''P.", "waltl''Depending upon the degree of mineralization, collagen tissues may be rigid (bone) or compliant (tendon) or have a gradient from rigid to compliant (cartilage).", "Collagen is also abundant in corneas, blood vessels, the gut, intervertebral discs, and the dentin in teeth.", "In muscle tissue, it serves as a major component of the endomysium.", "Collagen constitutes one to two percent of muscle tissue and accounts for 6% of the weight of the skeletal muscle tissue.", "The fibroblast is the most common cell that creates collagen.", "Gelatin, which is used in food and industry, is collagen that has been irreversibly hydrolyzed using heat, basic solutions or weak acids." ], [ "Etymology", "CollagenThe name ''collagen'' comes from the Greek κόλλα (''kólla''), meaning \"glue\", and suffix -γέν, ''-gen'', denoting \"producing\"." ], [ "Human types", "Over 90% of the collagen in the human body is type I collagen.", "However, as of 2011, 28 types of human collagen have been identified, described, and divided into several groups according to the structure they form.", "All of the types contain at least one triple helix.", "The number of types shows collagen's diverse functionality.", "* Fibrillar (Type I, II, III, V, XI)* Non-fibrillar** FACIT (Fibril Associated Collagens with Interrupted Triple Helices) (Type IX, XII, XIV, XIX, XXI)** Short chain (Type VIII, X)** Basement membrane (Type IV)** Multiplexin (Multiple Triple Helix domains with Interruptions) (Type XV, XVIII)** MACIT (Membrane Associated Collagens with Interrupted Triple Helices) (Type XIII, XVII)** Microfibril forming (Type VI)** Anchoring fibrils (Type VII)The five most common types are:* Type I: skin, tendon, vasculature, organs, bone (main component of the organic part of bone)* Type II: cartilage (main collagenous component of cartilage)* Type III: reticulate (main component of reticular fibers), commonly found alongside type I* Type IV: forms basal lamina, the epithelium-secreted layer of the basement membrane* Type V: cell surfaces, hair, and placenta" ], [ "In human biology", "===Cardiac===The collagenous cardiac skeleton which includes the four heart valve rings, is histologically, elastically and uniquely bound to cardiac muscle.", "The cardiac skeleton also includes the separating septa of the heart chambers – the interventricular septum and the atrioventricular septum.", "Collagen contribution to the measure of cardiac performance summarily represents a continuous torsional force opposed to the fluid mechanics of blood pressure emitted from the heart.", "The collagenous structure that divides the upper chambers of the heart from the lower chambers is an impermeable membrane that excludes both blood and electrical impulses through typical physiological means.", "With support from collagen, atrial fibrillation never deteriorates to ventricular fibrillation.", "Collagen is layered in variable densities with smooth muscle mass.", "The mass, distribution, age, and density of collagen all contribute to the compliance required to move blood back and forth.", "Individual cardiac valvular leaflets are folded into shape by specialized collagen under variable pressure.", "Gradual calcium deposition within collagen occurs as a natural function of aging.", "Calcified points within collagen matrices show contrast in a moving display of blood and muscle, enabling methods of cardiac imaging technology to arrive at ratios essentially stating blood in (cardiac input) and blood out (cardiac output).", "Pathology of the collagen underpinning of the heart is understood within the category of connective tissue disease.===Bone grafts===As the skeleton forms the structure of the body, it is vital that it maintains its strength, even after breaks and injuries.", "Collagen is used in bone grafting as it has a triple helical structure, making it a very strong molecule.", "It is ideal for use in bones, as it does not compromise the structural integrity of the skeleton.", "The triple helical structure of collagen prevents it from being broken down by enzymes, it enables adhesiveness of cells and it is important for the proper assembly of the extracellular matrix.===Tissue regeneration===Collagen scaffolds are used in tissue regeneration, whether in sponges, thin sheets, gels, or fibers.", "Collagen has favorable properties for tissue regeneration, such as pore structure, permeability, hydrophilicity, and stability in vivo.", "Collagen scaffolds also support deposition of cells, such as osteoblasts and fibroblasts, and once inserted, facilitate growth to proceed normally.===Reconstructive surgical uses===Collagens are widely employed in the construction of artificial skin substitutes used in the management of severe burns and wounds.", "These collagens may be derived from bovine, equine, porcine, or even human sources; and are sometimes used in combination with silicones, glycosaminoglycans, fibroblasts, growth factors and other substances.=== Wound healing ===Collagen is one of the body's key natural resources and a component of skin tissue that can benefit all stages of wound healing.", "When collagen is made available to the wound bed, closure can occur.", "Wound deterioration, followed sometimes by procedures such as amputation, can thus be avoided.Collagen is a natural product and is thus used as a natural wound dressing and has properties that artificial wound dressings do not have.", "It is resistant against bacteria, which is of vital importance in a wound dressing.", "It helps to keep the wound sterile, because of its natural ability to fight infection.", "When collagen is used as a burn dressing, healthy granulation tissue is able to form very quickly over the burn, helping it to heal rapidly.Throughout the four phases of wound healing, collagen performs the following functions:* Guiding function: Collagen fibers serve to guide fibroblasts.", "Fibroblasts migrate along a connective tissue matrix.", "* Chemotactic properties: The large surface area available on collagen fibers can attract fibrogenic cells which help in healing.", "* Nucleation: Collagen, in the presence of certain neutral salt molecules, can act as a nucleating agent causing formation of fibrillar structures.", "* Hemostatic properties: Blood platelets interact with the collagen to make a hemostatic plug." ], [ "Basic research", "Collagen is used in laboratory studies for cell culture, studying cell behavior and cellular interactions with the extracellular environment.", "Collagen is also widely used as a bioink for 3D bioprinting and biofabrication of 3D tissue models." ], [ "Biology", "The collagen protein is composed of a triple helix, which generally consists of two identical chains (α1) and an additional chain that differs slightly in its chemical composition (α2).", "The amino acid composition of collagen is atypical for proteins, particularly with respect to its high hydroxyproline content.", "The most common motifs in the amino acid sequence of collagen are glycine-proline-X and glycine-X-hydroxyproline, where X is any amino acid other than glycine, proline or hydroxyproline.", "The average amino acid composition for fish and mammal skin is given.", "Amino acid Abundance in mammal skin(residues/1000) Abundance in fish skin(residues/1000) Glycine 329 339 Proline 126 108 Alanine 109 114 Hydroxyproline 95 67 Glutamic acid 74 76 Arginine 49 52 Aspartic acid 47 47 Serine 36 46 Lysine 29 26 Leucine 24 23 Valine 22 21 Threonine 19 26 Phenylalanine 13 14 Isoleucine 11 11 Hydroxylysine 6 8 Methionine 6 13 Histidine 5 7 Tyrosine 3 3 Cysteine 1 1 Tryptophan 0 0" ], [ "Synthesis", "First, a three-dimensional stranded structure is assembled, with the amino acids glycine and proline as its principal components.", "This is not yet collagen but its precursor, procollagen.", "Procollagen is then modified by the addition of hydroxyl groups to the amino acids proline and lysine.", "This step is important for later glycosylation and the formation of the triple helix structure of collagen.", "Because the hydroxylase enzymes that perform these reactions require vitamin C as a cofactor, a long-term deficiency in this vitamin results in impaired collagen synthesis and scurvy.", "These hydroxylation reactions are catalyzed by two different enzymes: prolyl 4-hydroxylase and lysyl hydroxylase.", "The reaction consumes one ascorbate molecule per hydroxylation.The synthesis of collagen occurs inside and outside of the cell.", "The formation of collagen which results in fibrillary collagen (most common form) is discussed here.", "Meshwork collagen, which is often involved in the formation of filtration systems, is the other form of collagen.", "All types of collagens are triple helices, and the differences lie in the make-up of the alpha peptides created in step 2.# '''Transcription of mRNA''': About 44 genes are associated with collagen formation, each coding for a specific mRNA sequence, and typically have the \"''COL''\" prefix.", "The beginning of collagen synthesis begins with turning on genes which are associated with the formation of a particular alpha peptide (typically alpha 1, 2 or 3).# '''Pre-pro-peptide formation''': Once the final mRNA exits from the cell nucleus and enters into the cytoplasm, it links with the ribosomal subunits and the process of translation occurs.", "The early/first part of the new peptide is known as the signal sequence.", "The signal sequence on the N-terminal of the peptide is recognized by a signal recognition particle on the endoplasmic reticulum, which will be responsible for directing the pre-pro-peptide into the endoplasmic reticulum.", "Therefore, once the synthesis of new peptide is finished, it goes directly into the endoplasmic reticulum for post-translational processing.", "It is now known as preprocollagen.# '''Pre-pro-peptide to pro-collagen''': Three modifications of the pre-pro-peptide occur leading to the formation of the alpha peptide:## The signal peptide on the N-terminal is removed, and the molecule is now known as ''propeptide'' (not procollagen).## Hydroxylation of lysines and prolines on propeptide by the enzymes 'prolyl hydroxylase' and 'lysyl hydroxylase' (to produce hydroxyproline and hydroxylysine) occurs to aid cross-linking of the alpha peptides.", "This enzymatic step requires vitamin C as a cofactor.", "In scurvy, the lack of hydroxylation of prolines and lysines causes a looser triple helix (which is formed by three alpha peptides).## Glycosylation occurs by adding either glucose or galactose monomers onto the hydroxyl groups that were placed onto lysines, but not on prolines.## Once these modifications have taken place, three of the hydroxylated and glycosylated propeptides twist into a triple helix forming procollagen.", "Procollagen still has unwound ends, which will be later trimmed.", "At this point, the procollagen is packaged into a transfer vesicle destined for the Golgi apparatus.# '''Golgi apparatus modification''': In the Golgi apparatus, the procollagen goes through one last post-translational modification before being secreted out of the cell.", "In this step, oligosaccharides (not monosaccharides as in step 3) are added, and then the procollagen is packaged into a secretory vesicle destined for the extracellular space.# '''Formation of tropocollagen''': Once outside the cell, membrane bound enzymes known as collagen peptidases, remove the \"loose ends\" of the procollagen molecule.", "What is left is known as tropocollagen.", "Defects in this step produce one of the many collagenopathies known as Ehlers–Danlos syndrome.", "This step is absent when synthesizing type III, a type of fibrillar collagen.# '''Formation of the collagen fibril''': lysyl oxidase, an extracellular copper-dependent enzyme, produces the final step in the collagen synthesis pathway.", "This enzyme acts on lysines and hydroxylysines producing aldehyde groups, which will eventually undergo covalent bonding between tropocollagen molecules.", "This polymer of tropocollagen is known as a collagen fibril.Action of lysyl oxidase===Amino acids===Collagen has an unusual amino acid composition and sequence:* Glycine is found at almost every third residue.", "* Proline makes up about 17% of collagen.", "* Collagen contains two unusual derivative amino acids not directly inserted during translation.", "These amino acids are found at specific locations relative to glycine and are modified post-translationally by different enzymes, both of which require vitamin C as a cofactor.", "** Hydroxyproline derived from proline** Hydroxylysine derived from lysine – depending on the type of collagen, varying numbers of hydroxylysines are glycosylated (mostly having disaccharides attached).Cortisol stimulates degradation of (skin) collagen into amino acids.=== Collagen I formation ===Most collagen forms in a similar manner, but the following process is typical for type I:# Inside the cell## Two types of alpha chains – alpha-1 and alpha 2, are formed during translation on ribosomes along the rough endoplasmic reticulum (RER).", "These peptide chains known as preprocollagen, have registration peptides on each end and a signal peptide.## Polypeptide chains are released into the lumen of the RER.## Signal peptides are cleaved inside the RER and the chains are now known as pro-alpha chains.## Hydroxylation of lysine and proline amino acids occurs inside the lumen.", "This process is dependent on and consumes ascorbic acid (vitamin C) as a cofactor.## Glycosylation of specific hydroxylysine residues occurs.## Triple alpha helical structure is formed inside the endoplasmic reticulum from two alpha-1 chains and one alpha-2 chain.## Procollagen is shipped to the Golgi apparatus, where it is packaged and secreted into extracellular space by exocytosis.# Outside the cell## Registration peptides are cleaved and tropocollagen is formed by procollagen peptidase.## Multiple tropocollagen molecules form collagen fibrils, via covalent cross-linking (aldol reaction) by lysyl oxidase which links hydroxylysine and lysine residues.", "Multiple collagen fibrils form into collagen fibers.## Collagen may be attached to cell membranes via several types of protein, including fibronectin, laminin, fibulin and integrin.===Synthetic pathogenesis===Vitamin C deficiency causes scurvy, a serious and painful disease in which defective collagen prevents the formation of strong connective tissue.", "Gums deteriorate and bleed, with loss of teeth; skin discolors, and wounds do not heal.", "Prior to the 18th century, this condition was notorious among long-duration military, particularly naval, expeditions during which participants were deprived of foods containing vitamin C.An autoimmune disease such as lupus erythematosus or rheumatoid arthritis may attack healthy collagen fibers.Many bacteria and viruses secrete virulence factors, such as the enzyme collagenase, which destroys collagen or interferes with its production." ], [ "Molecular structure", "A single collagen molecule, tropocollagen, is used to make up larger collagen aggregates, such as fibrils.", "It is approximately 300 nm long and 1.5 nm in diameter, and it is made up of three polypeptide strands (called alpha peptides, see step 2), each of which has the conformation of a left-handed helix – this should not be confused with the right-handed alpha helix.", "These three left-handed helices are twisted together into a right-handed triple helix or \"super helix\", a cooperative quaternary structure stabilized by many hydrogen bonds.", "With type I collagen and possibly all fibrillar collagens, if not all collagens, each triple-helix associates into a right-handed super-super-coil referred to as the collagen microfibril.", "Each microfibril is interdigitated with its neighboring microfibrils to a degree that might suggest they are individually unstable, although within collagen fibrils, they are so well ordered as to be crystalline.Three polypeptides coil to form tropocollagen.", "Many tropocollagens then bind together to form a fibril, and many of these then form a fibre.A distinctive feature of collagen is the regular arrangement of amino acids in each of the three chains of these collagen subunits.", "The sequence often follows the pattern Gly-Pro-X or Gly-X-Hyp, where X may be any of various other amino acid residues.", "Proline or hydroxyproline constitute about 1/6 of the total sequence.", "With glycine accounting for the 1/3 of the sequence, this means approximately half of the collagen sequence is not glycine, proline or hydroxyproline, a fact often missed due to the distraction of the unusual GX1X2 character of collagen alpha-peptides.", "The high glycine content of collagen is important with respect to stabilization of the collagen helix as this allows the very close association of the collagen fibers within the molecule, facilitating hydrogen bonding and the formation of intermolecular cross-links.", "This kind of regular repetition and high glycine content is found in only a few other fibrous proteins, such as silk fibroin.Collagen is not only a structural protein.", "Due to its key role in the determination of cell phenotype, cell adhesion, tissue regulation, and infrastructure, many sections of its non-proline-rich regions have cell or matrix association/regulation roles.", "The relatively high content of proline and hydroxyproline rings, with their geometrically constrained carboxyl and (secondary) amino groups, along with the rich abundance of glycine, accounts for the tendency of the individual polypeptide strands to form left-handed helices spontaneously, without any intrachain hydrogen bonding.Because glycine is the smallest amino acid with no side chain, it plays a unique role in fibrous structural proteins.", "In collagen, Gly is required at every third position because the assembly of the triple helix puts this residue at the interior (axis) of the helix, where there is no space for a larger side group than glycine's single hydrogen atom.", "For the same reason, the rings of the Pro and Hyp must point outward.", "These two amino acids help stabilize the triple helix – Hyp even more so than Pro; a lower concentration of them is required in animals such as fish, whose body temperatures are lower than most warm-blooded animals.", "Lower proline and hydroxyproline contents are characteristic of cold-water, but not warm-water fish; the latter tend to have similar proline and hydroxyproline contents to mammals.", "The lower proline and hydroxyproline contents of cold-water fish and other poikilotherm animals leads to their collagen having a lower thermal stability than mammalian collagen.", "This lower thermal stability means that gelatin derived from fish collagen is not suitable for many food and industrial applications.The tropocollagen subunits spontaneously self-assemble, with regularly staggered ends, into even larger arrays in the extracellular spaces of tissues.", "Additional assembly of fibrils is guided by fibroblasts, which deposit fully formed fibrils from fibripositors.", "In the fibrillar collagens, molecules are staggered to adjacent molecules by about 67 nm (a unit that is referred to as 'D' and changes depending upon the hydration state of the aggregate).", "In each D-period repeat of the microfibril, there is a part containing five molecules in cross-section, called the \"overlap\", and a part containing only four molecules, called the \"gap\".", "These overlap and gap regions are retained as microfibrils assemble into fibrils, and are thus viewable using electron microscopy.", "The triple helical tropocollagens in the microfibrils are arranged in a quasihexagonal packing pattern.The D-period of collagen fibrils results in visible 67nm bands when observed by electron microscopy.There is some covalent crosslinking within the triple helices and a variable amount of covalent crosslinking between tropocollagen helices forming well-organized aggregates (such as fibrils).", "Larger fibrillar bundles are formed with the aid of several different classes of proteins (including different collagen types), glycoproteins, and proteoglycans to form the different types of mature tissues from alternate combinations of the same key players.", "Collagen's insolubility was a barrier to the study of monomeric collagen until it was found that tropocollagen from young animals can be extracted because it is not yet fully crosslinked.", "However, advances in microscopy techniques (i.e.", "electron microscopy (EM) and atomic force microscopy (AFM)) and X-ray diffraction have enabled researchers to obtain increasingly detailed images of collagen structure ''in situ''.", "These later advances are particularly important to better understanding the way in which collagen structure affects cell–cell and cell–matrix communication and how tissues are constructed in growth and repair and changed in development and disease.", "For example, using AFM–based nanoindentation it has been shown that a single collagen fibril is a heterogeneous material along its axial direction with significantly different mechanical properties in its gap and overlap regions, correlating with its different molecular organizations in these two regions.Collagen fibrils/aggregates are arranged in different combinations and concentrations in various tissues to provide varying tissue properties.", "In bone, entire collagen triple helices lie in a parallel, staggered array.", "40 nm gaps between the ends of the tropocollagen subunits (approximately equal to the gap region) probably serve as nucleation sites for the deposition of long, hard, fine crystals of the mineral component, which is hydroxylapatite (approximately) Ca10(OH)2(PO4)6.Type I collagen gives bone its tensile strength." ], [ "Associated disorders", "Collagen-related diseases most commonly arise from genetic defects or nutritional deficiencies that affect the biosynthesis, assembly, posttranslational modification, secretion, or other processes involved in normal collagen production.+'''Genetic defects of collagen genes''' '''Type''' '''Notes''' '''Gene(s)''' '''Disorders''' I This is the most abundant collagen of the human body.", "It is present in Scar tissue, the end product when tissue heals by repair.", "It is found in tendons, skin, artery walls, cornea, the endomysium surrounding muscle fibers, fibrocartilage, and the organic part of bones and teeth.", "COL1A1, COL1A2 Osteogenesis imperfecta, Ehlers–Danlos syndrome, infantile cortical hyperostosis a.k.a.", "Caffey's disease II Hyaline cartilage, makes up 50% of all cartilage protein.", "Vitreous humour of the eye.", "COL2A1 Collagenopathy, types II and XI III This is the collagen of granulation tissue and is produced quickly by young fibroblasts before the tougher type I collagen is synthesized.", "Reticular fiber.", "Also found in artery walls, skin, intestines and the uterus COL3A1 Ehlers–Danlos syndrome, Dupuytren's contracture IV Basal lamina; eye lens.", "Also serves as part of the filtration system in capillaries and the glomeruli of nephron in the kidney.", "COL4A1, COL4A2, COL4A3, COL4A4, COL4A5, COL4A6 Alport syndrome, Goodpasture's syndrome V Most interstitial tissue, assoc.", "with type I, associated with placenta COL5A1, COL5A2, COL5A3 Ehlers–Danlos syndrome (classical) VI Most interstitial tissue, assoc.", "with type I COL6A1, COL6A2, COL6A3, COL6A5 Ulrich myopathy, Bethlem myopathy, atopic dermatitis VII Forms anchoring fibrils in dermoepidermal junctions COL7A1 Epidermolysis bullosa dystrophica VIII Some endothelial cells COL8A1, COL8A2 Posterior polymorphous corneal dystrophy 2 IX FACIT collagen, cartilage, assoc.", "with type II and XI fibrils COL9A1, COL9A2, COL9A3 EDM2 and EDM3 X Hypertrophic and mineralizing cartilage COL10A1 Schmid metaphyseal dysplasia XI Cartilage COL11A1, COL11A2 Collagenopathy, types II and XI XII FACIT collagen, interacts with type I containing fibrils, decorin and glycosaminoglycans COL12A1 – XIII Transmembrane collagen, interacts with integrin a1b1, fibronectin and components of basement membranes like nidogen and perlecan.", "COL13A1 – XIV FACIT collagen, also known as undulin COL14A1 – XV – COL15A1 – XVI FACIT collagen COL16A1 – XVII Transmembrane collagen, also known as BP180, a 180 kDa protein COL17A1 Bullous pemphigoid and certain forms of junctional epidermolysis bullosa XVIII Source of endostatin COL18A1 – XIX FACIT collagen COL19A1 – XX – COL20A1 – XXI FACIT collagen COL21A1 – XXII FACIT collagen COL22A1 – XXIII MACIT collagen COL23A1 – XXIV – COL24A1 – XXV – COL25A1 – XXVI – EMID2 – XXVII – COL27A1 – XXVIII – COL28A1 – XXIX Epidermal collagen COL29A1 Atopic dermatitisIn addition to the above-mentioned disorders, excessive deposition of collagen occurs in scleroderma." ], [ "Diseases", "One thousand mutations have been identified in 12 out of more than 20 types of collagen.", "These mutations can lead to various diseases at the tissue level.Osteogenesis imperfecta – Caused by a mutation in ''type 1 collagen'', dominant autosomal disorder, results in weak bones and irregular connective tissue, some cases can be mild while others can be lethal.", "Mild cases have lowered levels of collagen type 1 while severe cases have structural defects in collagen.Chondrodysplasias – Skeletal disorder believed to be caused by a mutation in ''type 2 collagen'', further research is being conducted to confirm this.Ehlers–Danlos syndrome – Thirteen different types of this disorder, which lead to deformities in connective tissue, are known.", "Some of the rarer types can be lethal, leading to the rupture of arteries.", "Each syndrome is caused by a different mutation.", "For example, the vascular type (vEDS) of this disorder is caused by a mutation in ''collagen type 3''.Alport syndrome – Can be passed on genetically, usually as X-linked dominant, but also as both an autosomal dominant and autosomal recessive disorder, those with the condition have problems with their kidneys and eyes, loss of hearing can also develop during the childhood or adolescent years.Knobloch syndrome – Caused by a mutation in the COL18A1 gene that codes for the production of collagen XVIII.", "Patients present with protrusion of the brain tissue and degeneration of the retina; an individual who has family members with the disorder is at an increased risk of developing it themselves since there is a hereditary link." ], [ "Characteristics", "Collagen is one of the long, fibrous structural proteins whose functions are quite different from those of globular proteins, such as enzymes.", "Tough bundles of collagen called ''collagen fibers'' are a major component of the extracellular matrix that supports most tissues and gives cells structure from the outside, but collagen is also found inside certain cells.", "Collagen has great tensile strength, and is the main component of fascia, cartilage, ligaments, tendons, bone and skin.", "Along with elastin and soft keratin, it is responsible for skin strength and elasticity, and its degradation leads to wrinkles that accompany aging.", "It strengthens blood vessels and plays a role in tissue development.", "It is present in the cornea and lens of the eye in crystalline form.", "It may be one of the most abundant proteins in the fossil record, given that it appears to fossilize frequently, even in bones from the Mesozoic and Paleozoic.===Uses===A salami and the collagen casing (below) it came inCollagen has a wide variety of applications, from food to medical.", "In the medical industry, it is used in cosmetic surgery and burn surgery.", "In the food sector, one use example is in casings for sausages.If collagen is subject to sufficient denaturation, such as by heating, the three tropocollagen strands separate partially or completely into globular domains, containing a different secondary structure to the normal collagen polyproline II (PPII) of random coils.", "This process describes the formation of gelatin, which is used in many foods, including flavored gelatin desserts.", "Besides food, gelatin has been used in pharmaceutical, cosmetic, and photography industries.", "It is also used as a dietary supplement, and has been advertised as a potential remedy against the ageing process.From the Greek for glue, ''kolla'', the word collagen means \"glue producer\" and refers to the early process of boiling the skin and sinews of horses and other animals to obtain glue.", "Collagen adhesive was used by Egyptians about 4,000 years ago, and Native Americans used it in bows about 1,500 years ago.", "The oldest glue in the world, carbon-dated as more than 8,000 years old, was found to be collagen – used as a protective lining on rope baskets and embroidered fabrics, to hold utensils together, and in crisscross decorations on human skulls.", "Collagen normally converts to gelatin, but survived due to dry conditions.", "Animal glues are thermoplastic, softening again upon reheating, so they are still used in making musical instruments such as fine violins and guitars, which may have to be reopened for repairs – an application incompatible with tough, synthetic plastic adhesives, which are permanent.", "Animal sinews and skins, including leather, have been used to make useful articles for millennia.Gelatin-resorcinol-formaldehyde glue (and with formaldehyde replaced by less-toxic pentanedial and ethanedial) has been used to repair experimental incisions in rabbit lungs.=== Cosmetics ===Bovine collagen is widely used in dermal fillers for aesthetic correction of wrinkles and skin aging.", "Collagen cremes are also widely sold even though collagen cannot penetrate the skin because its fibers are too large.", "Most research on collagen supplements has been funded by industries that could benefit from a positive study result." ], [ "History", "The molecular and packing structures of collagen eluded scientists over decades of research.", "The first evidence that it possesses a regular structure at the molecular level was presented in the mid-1930s.", "Research then concentrated on the conformation of the collagen monomer, producing several competing models, although correctly dealing with the conformation of each individual peptide chain.", "The triple-helical \"Madras\" model, proposed by G. N. Ramachandran in 1955, provided an accurate model of quaternary structure in collagen.", "This model was supported by further studies of higher resolution in the late 20th century.The packing structure of collagen has not been defined to the same degree outside of the fibrillar collagen types, although it has been long known to be hexagonal.", "As with its monomeric structure, several conflicting models propose either that the packing arrangement of collagen molecules is 'sheet-like', or is microfibrillar.", "The microfibrillar structure of collagen fibrils in tendon, cornea and cartilage was imaged directly by electron microscopy in the late 20th century and early 21st century.", "The microfibrillar structure of rat tail tendon was modeled as being closest to the observed structure, although it oversimplified the topological progression of neighboring collagen molecules, and so did not predict the correct conformation of the discontinuous D-periodic pentameric arrangement termed ''microfibril''." ], [ "See also", "* Collagen hybridizing peptide, a peptide that can bind to denatured collagen* Hypermobility spectrum disorder* Metalloprotease inhibitor* Osteoid, a collagen-containing component of bone* Collagen loss" ], [ "References" ] ]
wikipedia
[ [ "Calvin and Hobbes" ], [ "Introduction", "'''''Calvin and Hobbes''''' is a daily American comic strip created by cartoonist Bill Watterson that was syndicated from November 18, 1985, to December 31, 1995.Commonly described as \"the last great newspaper comic\", ''Calvin and Hobbes'' has enjoyed broad and enduring popularity, influence, and academic and philosophical interest.", "''Calvin and Hobbes'' follows the humorous antics of the title characters: Calvin, a precocious, mischievous, and adventurous six-year-old boy; and his friend Hobbes, a sardonic tiger.", "Set in the suburban United States of the 1980s and 1990s, the strip depicts Calvin's frequent flights of fancy and friendship with Hobbes.", "It also examines Calvin's relationships with his long-suffering parents and with his classmates, especially his neighbor Susie Derkins.", "Hobbes's dual nature is a defining motif for the strip: to Calvin, Hobbes is a living anthropomorphic tiger, while all the other characters seem to see Hobbes as an inanimate stuffed toy, though Watterson has not clarified exactly how Hobbes is perceived by others, or whether he is real or an imaginary friend.", "Though the series does not frequently mention specific political figures or ongoing events, it does explore broad issues like environmentalism, public education, and philosophical quandaries.At the height of its popularity, ''Calvin and Hobbes'' was featured in over 2,400 newspapers worldwide.", "In 2010, reruns of the strip appeared in more than 50 countries, and nearly 45 million copies of the ''Calvin and Hobbes'' books had been sold worldwide." ], [ "History", "=== Development ===''Calvin and Hobbes'' was conceived when Bill Watterson, while working in an advertising job he detested, began devoting his spare time to developing a newspaper comic for potential syndication.", "He explored various strip ideas but all were rejected by the syndicates.", "United Feature Syndicate finally responded positively to one strip called ''The Doghouse'', which featured a side character (the main character's little brother) who had a stuffed tiger.", "United identified these characters as the strongest and encouraged Watterson to develop them as the center of their own strip.", "Though United Feature ultimately rejected the new strip as lacking in marketing potential, Universal Press Syndicate took it up.=== Launch and early success (1985–1990) ===The first ''Calvin and Hobbes'' strip was published on November 18, 1985 in 35 newspapers.", "The strip quickly became popular.", "Within a year of syndication, the strip was published in roughly 250 newspapers and proved to have international appeal with translation and wide circulation outside the United States.Although ''Calvin and Hobbes'' underwent continual artistic development and creative innovation over the period of syndication, the earliest strips demonstrated a remarkable consistency with the latest.", "Watterson introduced all the major characters within the first three weeks and made no changes to the central cast over the strip's 10-year history.", "By April 5, 1987, Watterson was featured in an article in the ''Los Angeles Times''.", "''Calvin and Hobbes'' earned Watterson the Reuben Award from the National Cartoonists Society in the Outstanding Cartoonist of the Year category, first in 1986 and again in 1988.He was nominated another time in 1992.The Society awarded him the Humor Comic Strip Award for 1988.", "''Calvin and Hobbes'' has also won several more awards.As his creation grew in popularity, there was strong interest from the syndicate to merchandise the characters and expand into other forms of media.", "Watterson's contract with the syndicate allowed the characters to be licensed without the creator's consent, as was standard at the time.", "Nevertheless, Watterson had leverage by threatening to simply walk away from the comic strip.This dynamic played out in a long and emotionally draining battle between Watterson and his syndicate editors.", "By 1991, Watterson had achieved his goal of securing a new contract that granted him legal control over his creation and all future licensing arrangements.=== Creative control (1991–1995) ===Having achieved his objective of creative control, Watterson's desire for privacy subsequently reasserted itself and he ceased all media interviews, relocated to New Mexico, and largely disappeared from public engagements, refusing to attend the ceremonies of any of the cartooning awards he won.", "The pressures of the battle over merchandising led to Watterson taking an extended break from May 5, 1991, to February 1, 1992, a move that was virtually unprecedented in the world of syndicated cartoonists.During Watterson's first sabbatical from the strip, Universal Press Syndicate continued to charge newspapers full price to re-run old ''Calvin and Hobbes'' strips.", "Few editors approved of the move, but the strip was so popular that they had no choice but to continue to run it for fear that competing newspapers might pick it up and draw its fans away.", "Watterson returned to the strip in 1992 with plans to produce his Sunday strip as an unbreakable half of a newspaper or tabloid page.", "This made him only the second cartoonist since Garry Trudeau to have sufficient popularity to demand more space and control over the presentation of his work.Watterson took a second sabbatical from April 3 through December 31, 1994.His return came with an announcement that ''Calvin and Hobbes'' would be concluding at the end of 1995.Stating his belief that he had achieved everything that he wanted to within the medium, he announced his intention to work on future projects at a slower pace with fewer artistic compromises.The final strip ran on Sunday, December 31, 1995, depicting Calvin and Hobbes sledding down a snowy hill after a fresh snowfall with Calvin exclaiming “Let's go exploring!", "\"Speaking to NPR in 2005, animation critic Charles Solomon opined that the final strip \"left behind a hole in the comics page that no strip has been able to fill.\"" ], [ "Sunday formatting", "full, third, and quarter pages (optionally discarding panels 1 and 2).", "However, Watterson wished to draw comics which did not conform to the standard panel division.|alt=|205x205pxSyndicated comics were typically published six times a week in black and white, with a Sunday supplement version in a larger, full color format.", "This larger format version of the strip was constrained by mandatory layout requirements that made it possible for newspaper editors to format the strip for different page sizes and layouts.Watterson grew increasingly frustrated by the shrinking of the available space for comics in the newspapers and the mandatory panel divisions that restricted his ability to produce better artwork and more creative storytelling.", "He lamented that without space for anything more than simple dialogue or sparse artwork, comics as an art form were becoming dilute, bland, and unoriginal.Watterson longed for the artistic freedom allotted to classic strips such as ''Little Nemo'' and ''Krazy Kat'', and in 1989 he gave a sample of what could be accomplished with such liberty in the opening pages of the Sunday strip compilation, ''The Calvin and Hobbes Lazy Sunday Book—''an 8-page previously unpublished Calvin story fully illustrated in watercolor.", "The same book contained an afterword from the artist himself, reflecting on a time when comic strips were allocated a whole page of the newspaper and every comic was like a \"color poster\".Within two years, Watterson was ultimately successful in negotiating a deal that provided him more space and creative freedom.", "Following his 1991 sabbatical, Universal Press announced that Watterson had decided to sell his Sunday strip as an unbreakable half of a newspaper or tabloid page.", "Many editors and even a few cartoonists including Bil Keane (''The Family Circus'') and Bruce Beattie (''Snafu'') criticized him for what they perceived as arrogance and an unwillingness to abide by the normal practices of the cartoon business.", "Others, including Bill Amend (''Foxtrot''), Johnny Hart (''BC'', ''Wizard of Id'') and Barbara Brandon (''Where I'm Coming From'') supported him.", "The American Association of Sunday and Feature Editors even formally requested that Universal reconsider the changes.", "Watterson's own comments on the matter was that \"editors will have to judge for themselves whether or not Calvin and Hobbes deserves the extra space.", "If they don't think the strip carries its own weight, they don't have to run it.\"", "Ultimately only 15 newspapers cancelled the strip in response to the layout changes." ], [ "Sabbaticals", "Bill Watterson took two sabbaticals from the daily requirements of producing the strip.", "The first took place from May 5, 1991, to February 1, 1992, and the second from April 3 through December 31, 1994.These sabbaticals were included in the new contract Watterson managed to negotiate with Universal Features in 1990.The sabbaticals were proposed by the syndicate themselves, who, fearing Watterson's complete burnout, endeavored to get another five years of work from their star artist.Watterson remains only the third cartoonist with sufficient popularity and stature to receive a sabbatical from their syndicate, the first two being Garry Trudeau (''Doonesbury'') in 1983 and Gary Larson (''The Far Side'') in 1989.Typically, cartoonists are expected to produce sufficient strips to cover any period that they may wish to take off.", "Watterson's lengthy sabbaticals received some mild criticism from his fellow cartoonists including Greg Evans (''Luann''); and Charles Schulz (''Peanuts''), one of Watterson's major artistic influences, even called it a \"puzzle\".", "Some cartoonists resented the idea that Watterson worked harder than others, while others supported it.", "At least one newspaper editor noted that the strip was the most popular in the country and stated that he \"earned it\"." ], [ "Merchandising", "Despite the popularity of ''Calvin and Hobbes'', the strip remains notable for the almost complete lack of official product merchandising.", "Watterson held that comic strips should stand on their own as an art form and although he did not start out completely opposed to merchandising in all forms (or even for all comic strips), he did reject an early syndication deal that involved incorporating a more marketable, licensed character into his strip.", "In spite of being an unproven cartoonist, and having been flown all the way to New York to discuss the proposal, Watterson reflexively resented the idea of \"cartooning by committee\" and turned it down.When ''Calvin and Hobbes'' was accepted by Universal Syndicate, and began to grow in popularity, Watterson found himself at odds with the syndicate, which urged him to begin merchandising the characters and touring the country to promote the first collections of comic strips.", "Watterson refused, believing that the integrity of the strip and its artist would be undermined by commercialization, which he saw as a major negative influence in the world of cartoon art, and that licensing his character would only violate the spirit of his work.", "He gave an example of this in discussing his opposition to a Hobbes plush toy: that if the essence of Hobbes' nature in the strip is that it remain unresolved whether he is a real tiger or a stuffed toy, then creating a real stuffed toy would only destroy the magic.", "However, having initially signed away control over merchandising in his initial contract with the syndicate, Watterson commenced a lengthy and emotionally draining battle with Universal to gain control over his work.", "Ultimately Universal did not approve any products against Watterson's wishes, understanding that, unlike other comic strips, it would be nearly impossible to separate the creator from the strip if Watterson chose to walk away.One estimate places the value of licensing revenue forgone by Watterson at $300–$400 million.", "Almost no legitimate ''Calvin and Hobbes'' merchandise exists.", "Exceptions produced during the strip's original run include two 16-month calendars (1988–89 and 1989–90), a t-shirt for the Smithsonian Exhibit, ''Great American Comics: 100 Years of Cartoon Art'' (1990) and the textbook ''Teaching with Calvin and Hobbes'', which has been described as \"perhaps the most difficult piece of official ''Calvin and Hobbes'' memorabilia to find.\"", "In 2010, Watterson did allow his characters to be included in a series of United States Postal Service stamps honoring five classic American comics.", "Licensed prints of ''Calvin and Hobbes'' were made available and have also been included in various academic works.The strip's immense popularity has led to the appearance of various counterfeit items such as window decals and T-shirts that often feature crude humor, binge drinking and other themes that are not found in Watterson's work.", "Images from one strip in which Calvin and Hobbes dance to loud music at night were commonly used for copyright violations.", "After threat of a lawsuit alleging infringement of copyright and trademark, some sticker makers replaced Calvin with a different boy, while other makers made no changes.", "Watterson wryly commented, \"I clearly miscalculated how popular it would be to show Calvin urinating on a Ford logo,\" but later added, \"long after the strip is forgotten, they are my ticket to immortality\".===Animation===Watterson has expressed admiration for animation as an artform.", "In a 1989 interview in ''The Comics Journal'' he described the appeal of being able to do things with a moving image that cannot be done by a simple drawing: the distortion, the exaggeration and the control over the length of time an event is viewed.", "However, although the visual possibilities of animation appealed to Watterson, the idea of finding a voice for Calvin made him uncomfortable, as did the idea of working with a team of animators.", "Ultimately, ''Calvin and Hobbes'' was never made into an animated series.", "Watterson later stated in ''The Calvin and Hobbes Tenth Anniversary Book'' that he liked the fact that his strip was a \"low-tech, one-man operation,\" and that he took great pride in the fact that he drew every line and wrote every word on his own.", "Calls from major Hollywood figures interested in an adaptation of his work, including Jim Henson, George Lucas and Steven Spielberg, were never returned and in a 2013 interview Watterson stated that he had \"zero interest\" in an animated adaptation as there was really no upside for him in doing so." ], [ "Style and influences", "The strip borrows several elements and themes from three major influences: Walt Kelly's ''Pogo'', George Herriman's ''Krazy Kat'' and Charles M. Schulz's ''Peanuts''.", "Schulz and Kelly particularly influenced Watterson's outlook on comics during his formative years.Notable elements of Watterson's artistic style are his characters' diverse and often exaggerated expressions (particularly those of Calvin), elaborate and bizarre backgrounds for Calvin's flights of imagination, expressions of motion and frequent visual jokes and metaphors.", "In the later years of the strip, with more panel space available for his use, Watterson experimented more freely with different panel layouts, art styles, stories without dialogue and greater use of white space.", "He also experimented with his tools, once inking a strip with a stick from his yard in order to achieve a particular look.", "He also makes a point of not showing certain things explicitly: the \"Noodle Incident\" and the children's book ''Hamster Huey and the Gooey Kablooie'' are left to the reader's imagination, where Watterson was sure they would be \"more outrageous\" than he could portray." ], [ "Production and technique", "\"Calvin runs through the streets of London\" temporary illustration in Barking, LondonWatterson's technique started with minimalist pencil sketches drawn with a light pencil (though the larger Sunday strips often required more elaborate work) on a piece of Bristol board, with his brand of choice being Strathmore because he felt it held the drawings better on the page as opposed to the cheaper brands (Watterson said he initially used any cheap pad of Bristol board his local supply store had but switched to Strathmore after he found himself growing more and more displeased with the results).", "He would then use a small sable brush and India ink to fill in the rest of the drawing, saying that he did not want to simply trace over his penciling and thus make the inking more spontaneous.", "He lettered dialogue with a Rapidograph fountain pen, and he used a crowquill pen for odds and ends.", "Mistakes were covered with various forms of correction fluid, including the type used on typewriters.", "Watterson was careful in his use of color, often spending a great deal of time in choosing the right colors to employ for the weekly Sunday strip; his technique was to cut the color tabs the syndicate sent him into individual squares, lay out the colors, and then paint a watercolor approximation of the strip on tracing paper over the Bristol board and then mark the strip accordingly before sending it on.", "When ''Calvin and Hobbes'' began there were 64 colors available for the Sunday strips.", "For the later Sunday strips Watterson had 125 colors as well as the ability to fade the colors into each other." ], [ "Main characters", "===Calvin===The main character, CalvinCalvin, named after the 16th-century theologian John Calvin, is a six-year-old boy with spiky blond hair and a distinctive red-and-black striped shirt, black pants and sneakers.", "Despite his poor grades in school, Calvin demonstrates his intelligence through a sophisticated vocabulary, philosophical mind and creative/artistic talent.", "Watterson described Calvin as having \"not much of a filter between his brain and his mouth\", a \"little too intelligent for his age\", lacking in restraint and not yet having the experience to \"know the things that you shouldn't do.\"", "The comic strip largely revolves around Calvin's inner world and his largely antagonistic experiences with those outside of it (fellow students, authority figures and his parents).===Hobbes===HobbesFrom Calvin's point of view, Hobbes is an anthropomorphic tiger much larger than Calvin and full of independent attitudes and ideas.", "When a scene includes any other human, Hobbes appears as a stuffed animal, usually seated at an off-kilter angle with a blank facial expression.", "The true nature of the character is never resolved, instead as Watterson describes, a 'grown-up' version of reality is juxtaposed against Calvin's, with the reader left to \"decide which is truer\".", "Hobbes is based on a cat Watterson owned, a grey tabby named Sprite.", "Sprite inspired the length of Hobbes' body as well as his personality.", "Although Hobbes' humor stems from acting like a human, Watterson maintained Sprite's feline attitude.Hobbes is named after 17th-century philosopher Thomas Hobbes, who held what Watterson describes as \"a dim view of human nature.\"", "He typically exhibits a greater understanding of consequences than Calvin, but rarely intervenes in Calvin's activities beyond a few oblique warnings.", "He often likes to sneak up and pounce on Calvin, especially at the front door when Calvin is returning home from school.", "The friendship between the two characters provides the core dynamic of the strip.===Calvin's parents===The unnamed parents of CalvinCalvin's mother and father are typical middle-class parents who are relatively down to earth and whose sensible attitudes serve as a foil for Calvin's outlandish behavior.", "Calvin's father is a patent attorney (like Watterson's own father), while his mother is a stay-at-home mom.", "Both parents are unnamed throughout the entire strip, as Watterson insists, \"As far as the strip is concerned, they are important only as Calvin's mom and dad.", "\"Watterson recounts that some fans are angered by the sometimes sardonic way that Calvin's parents respond to him.", "In response, Watterson defends what Calvin's parents do, remarking that in the case of parenting a kid like Calvin, \"I think they do a better job than I would.\"", "Calvin's father is overly concerned with \"character building\" activities in a number of strips, either in the things he makes Calvin do or in the austere eccentricities of his own lifestyle.===Susie Derkins===Susie Derkins, Calvin's classmateSusie Derkins, who first appears early in the strip and is the only important character with both a first and last name, lives on Calvin's street and is one of his classmates.", "Her last name apparently derives from the pet beagle owned by Watterson's wife's family.Susie is studious and polite (though she can be aggressive if sufficiently provoked), and she likes to play house or host tea parties with her stuffed animals.", "She also plays imaginary games with Calvin in which she acts as a high-powered lawyer or politician and wants Calvin to pretend to be her househusband.", "Though both of them are typically loath to admit it, Calvin and Susie exhibit many common traits and inclinations.", "For example, the reader occasionally sees Susie with a stuffed rabbit named \"Mr.", "Bun.\"", "Much like Calvin, Susie has a mischievous (and sometimes aggressive) streak as well, which the reader witnesses whenever she subverts Calvin's attempts to cheat on school tests by feeding him incorrect answers, or whenever she fights back after Calvin attacks her with snowballs or water balloons.Hobbes often openly expresses romantic feelings for Susie, to Calvin's disgust.", "In contrast, Calvin started a club (of which he and Hobbes are the only members) that he calls G.R.O.S.S.", "('''G'''et '''R'''id '''O'''f '''S'''limy Girl'''S''') and, while holding \"meetings\" in Calvin's tree house or in the \"box of secrecy\" in Calvin's room, they usually come up with some plot against Susie.", "In one instance, Calvin steals one of Susie's dolls and holds it for ransom, only to have Susie retaliate by nabbing Hobbes.", "Watterson admits that Calvin and Susie have a nascent crush on each other and that Susie is a reference to the type of woman whom Watterson himself found attractive and eventually married.Susie features as a main character in two of the five storylines that appear in ''Teaching with Calvin and Hobbes''.===Secondary characters=== Calvin also interacts with a handful of secondary characters.", "Several of these, including '''Rosalyn''', his babysitter; '''Miss Wormwood''', his teacher; and '''Moe''', the school bully, recur regularly through the duration of the strip." ], [ "Recurring elements and themes", "===Art and academia===Watterson used the strip to poke fun at the art world, principally through Calvin's unconventional creations of snowmen but also through other expressions of childhood art.", "When Miss Wormwood complains that he is wasting class time drawing impossible things (a ''Stegosaurus'' in a rocket ship, for example), Calvin proclaims himself \"on the cutting edge of the ''avant-garde''.\"", "He begins exploring the medium of snow when a warm day melts his snowman.", "His next sculpture \"speaks to the horror of our own mortality, inviting the viewer to contemplate the evanescence of life.\"", "In later strips, Calvin's creative instincts diversify to include sidewalk drawings (or, as he terms them, examples of \"suburban postmodernism\").Watterson also lampooned the academic world.", "In one example, Calvin carefully crafts an \"artist's statement\", claiming that such essays convey more messages than artworks themselves ever do (Hobbes blandly notes, \"You misspelled ''Weltanschauung''\").", "He indulges in what Watterson calls \"pop psychobabble\" to justify his destructive rampages and shift blame to his parents, citing \"toxic codependency.\"", "In one instance, he pens a book report based on the theory that the purpose of academic writing is to \"inflate weak ideas, obscure poor reasoning and inhibit clarity,\" entitled ''The Dynamics of Interbeing and Monological Imperatives in Dick and Jane: A Study in Psychic Transrelational Gender Modes''.", "Displaying his creation to Hobbes, he remarks, \"Academia, here I come!\"", "Watterson explains that he adapted this jargon (and similar examples from several other strips) from an actual book of art criticism.Overall, Watterson's satirical essays serve to attack both sides, criticizing both the commercial mainstream and the artists who are supposed to be \"outside\" it.", "The strip on Sunday, June 21, 1992, criticized the naming of The Big Bang theory as not evocative of the wonders behind it and coined the term \"Horrendous Space Kablooie\", an alternative that achieved some informal popularity among scientists and was often shortened to \"the HSK.\"", "The term has also been referred to in newspapers, books and university courses.===Calvin's alter-egos===Calvin imagines himself as many great creatures and other people, including dinosaurs, elephants, jungle-farers and superheroes.", "Three of his alter egos are well-defined and recurrent:*\"'''Spaceman Spiff'''\" is a heroic spacefarer who narrates his adventures in the third person.", "As Spiff, Calvin battles aliens (typically his parents or teacher, but also sometimes other kids his age) with a ray gun known as a \"zorcher\" (later \"frap-ray blaster\", \"death ray blaster\" or \"atomic napalm neutralizer\") and travels to distant planets (his house, school or neighborhood), often crashing unhurt on a planet.", "Calvin's self-narration as Spaceman Spiff is frequently riddled with alliteration: \"Zounds!", "Zorched by Zarches, Spaceman Spiff's crippled craft crashes on planet Plootarg!\"", "Watterson has stated the idea of Spaceman Spiff came from an earlier attempt as a cartoon, and is meant as a parody of Flash Gordon.", "* \"'''Tracer Bullet'''\" is a hardboiled private eye, who says he has eight slugs in him (\"One's lead, and the rest are bourbon.\").", "In one story, Bullet is called to a case in which a \"pushy dame\" (Calvin's mother) accuses him of destroying an expensive lamp (broken during an indoor football game between Calvin and Hobbes).", "Later, he is snatched by the pushy dame's \"hired goon\" (Calvin's father having a talk with him).", "In another, he \"investigates\" a math word problem during class, \"closing the case\" with an answer of 1,000,000,000 when the correct response was 15.He made his debut when Calvin donned a fedora in order to hide a terrible haircut Hobbes had given him.", "These strips are drawn in elaborate, shadowy black-and-white that evoke film noir.", "Watterson did not attempt Tracer Bullet stories often, due to the time-consuming way the strip needed to be drawn and inked.", "* \"'''Stupendous Man'''\" is a superhero who wears a mask and a cape (made by Calvin's mother) and narrates his own adventures.", "While Calvin is in character as Stupendous Man, he refers to his alter ego as a mild-mannered millionaire playboy.", "Stupendous Man almost always \"suffers defeat\" at the hands of his opponent.", "When Hobbes asks if Stupendous Man has ever won any battles, Calvin says all his battles are \"moral victories.\"", "Stupendous Man's nemeses include \"Mom-Lady\" (Calvin's mom), \"Annoying Girl\" (Susie Derkins), \"Crab Teacher\" (Miss Wormwood) and \"Baby-Sitter Girl\" (Rosalyn).", "Some of the \"super powers\" of the villains have been revealed: Mom-Lady has a \"mind scrambling eyeball ray\" that wills the victim to \"do her nefarious bidding\"; and Baby Sitter Girl has a similar power of using a \"psycho beam\" which weakens \"Stupendous Man's stupendous will\".", "The \"powers\" of Annoying Girl and Crab Teacher are never revealed.", "Calvin often tries to pretend he and \"Stupendous Man\" are two different people, but it fails to work.", "Stupendous Man has multiple \"superpowers\", including, but not limited to, super strength, the ability to fly, various vision powers such as \"high-speed vision\", \"muscles of magnitude\" and a stomach of steel.===Cardboard boxes===Calvin duplicating himself using a cardboard box, as seen on the cover of ''Scientific Progress Goes \"Boink\"''Calvin also has several adventures involving corrugated cardboard boxes, which he adapts for many imaginative and elaborate uses.", "In one strip, when Calvin shows off his Transmogrifier, a device that transforms its user into any desired creature or item, Hobbes remarks, \"It's amazing what they do with corrugated cardboard these days.\"", "Calvin is able to change the function of the boxes by rewriting the label and flipping the box onto another side.", "In this way, a box can be used not only for its conventional purposes (a storage container for water balloons, for example), but also as a flying time machine, a duplicator, a transmogrifier or, with the attachment of a few wires and a colander, a \"Cerebral Enhance-o-tron.", "\"In the real world, Calvin's antics with his box have had varying effects.", "When he transmogrified into a tiger, he still appeared as a regular human child to his parents.", "However, in a story where he made several duplicates of himself, his parents are seen interacting with what does seem like multiple Calvins, including in a strip where two of him are seen in the same panel as his father.", "It is ultimately unknown what his parents do or do not see, as Calvin tries to hide most of his creations (or conceal their effects) so as not to traumatize them.In addition, Calvin uses a cardboard box as a sidewalk kiosk to sell things.", "Often, Calvin offers merchandise no one would want, such as \"suicide drink\", \"a swift kick in the butt\" for one dollar or a \"frank appraisal of your looks\" for fifty cents.", "In one strip, he sells \"happiness\" for ten cents, hitting the customer in the face with a water balloon and explaining that he meant his own happiness.", "In another strip, he sold \"insurance\", firing a slingshot at those who refused to buy it.", "In some strips, he tried to sell \"great ideas\" and, in one earlier strip, he attempted to sell the family car to obtain money for a grenade launcher.", "In yet another strip, he sells \"life\" for five cents, where the customer receives nothing in return, which, in Calvin's opinion, is life.The box has also functioned as an alternate secret meeting place for G.R.O.S.S., as the \"Box of Secrecy\".Calvin and Hobbes playing Calvinball with an assortment of sporting equipment===Calvinball===Calvinball is an improvisational sport/game introduced in a 1990 storyline that involved Calvin's negative experience of joining the school baseball team.", "Calvinball is a nomic or self-modifying game, a contest of wits, skill and creativity rather than stamina or athletic skill.", "The game is portrayed as a rebellion against conventional team sports and became a staple of the final five years of the comic.", "The only consistent rules of the game are that Calvinball may never be played with the same rules twice and that each participant must wear a mask.When asked how to play, Watterson stated: \"It's pretty simple: you make up the rules as you go.\"", "In most appearances of the game, a comical array of conventional and non-conventional sporting equipment is involved, including a croquet set, a badminton set, assorted flags, bags, signs, a hobby horse, water buckets and balloons, with humorous allusions to unseen elements such as \"time-fracture wickets\".", "Scoring is portrayed as arbitrary and nonsensical (\"Q to 12\" and \"oogy to boogy\") and the lack of fixed rules leads to lengthy argument between the participants as to who scored, where the boundaries are, and when the game is finished.", "Usually, the contest results in Calvin being outsmarted by Hobbes.", "The game has been described in one academic work not as a new game based on fragments of an older one, but as the \"constant connecting and disconnecting of parts, the constant evasion of rules or guidelines based on collective creativity.", "\"===Snowmen and other snow art===Calvin often creates horrendous/dark humor scenes with his snowmen and other snow sculptures.", "He uses the snowman for social commentary, revenge or pure enjoyment.", "Examples include Snowman Calvin being yelled at by Snowman Dad to shovel the snow; one snowman eating snow cones scooped out of a second snowman, who is lying on the ground with an ice-cream scoop in his back; a \"snowman house of horror\"; and snowmen representing people he hates.", "\"The ones I ''really'' hate are small, so they'll melt faster,\" he says.", "There was even an occasion on which Calvin accidentally brought a snowman to life and it made itself and a small army into \"deranged mutant killer monster snow goons.", "\"Calvin's snow art is often used as a commentary on art in general.", "For example, Calvin has complained more than once about the lack of originality in other people's snow art and compared it with his own grotesque snow sculptures.", "In one of these instances, Calvin and Hobbes claim to be the sole guardians of high culture; in another, Hobbes admires Calvin's willingness to put artistic integrity above marketability, causing Calvin to reconsider and make an ordinary snowman.===Wagon and sled rides===Calvin and Hobbes frequently ride downhill in a wagon or sled (depending on the season), as a device to add some physical comedy to the strip and because, according to Watterson, \"it's a lot more interesting ... than talking heads.\"", "While the ride is sometimes the focus of the strip, it also frequently serves as a counterpoint or visual metaphor while Calvin ponders the meaning of life, death, God, philosophy or a variety of other weighty subjects.", "Many of their rides end in spectacular crashes which leave them battered, beaten up and broken, a fact which convinces Hobbes to sometimes hop off before a ride even begins.", "In the final strip, Calvin and Hobbes depart on their sled to go exploring.", "This theme is similar (perhaps even an homage) to scenes in Walt Kelly's ''Pogo''.", "Calvin and Hobbes' sled has been described as the most famous sled in American arts since ''Citizen Kane''.===G.R.O.S.S.", "(Get Rid of Slimy GirlS) ===G.R.O.S.S.", "(which is a backronym for '''G'''et '''R'''id '''O'''f '''S'''limy Girl'''S''', \"otherwise it doesn't spell anything\") is a club in which Calvin and Hobbes are the only members.", "The club was founded in the garage of their house, but to clear space for its activities, Calvin and (purportedly) Hobbes push Calvin's parents' car, causing it to roll into a ditch (but not suffer damage); the incident prompts the duo to change the club's location to Calvin's treehouse.", "They hold meetings that involve finding ways to annoy and discomfort Susie Derkins, a girl and enemy of their club.", "Notable actions include planting a fake secret tape near her in attempt to draw her in to a trap, trapping her in a closet at their house and creating elaborate water balloon traps.", "Calvin gave himself and Hobbes important positions in the club, Calvin being \"Dictator-for-Life\" and Hobbes being \"President-and-First-Tiger\".", "They go into Calvin's treehouse for their club meetings and often get into fights during them.", "The password to get into the treehouse is intentionally long and difficult, which has on at least one occasion ruined Calvin's plans.", "As Hobbes is able to climb the tree without the rope, he is usually the one who comes up with the password, which often involves heaping praise upon tigers.", "An example of this can be seen in the comic strip where Calvin, rushing to get into the treehouse to throw things at a passing Susie Derkins, insults Hobbes, who is in the treehouse and thus has to let down the rope.", "Hobbes forces Calvin to say the password for insulting him.", "By the time Susie arrives, in time to hear Calvin saying some of the password, causing him to stumble, Calvin is on \"''Verse Seven:'' Tigers are perfect!/The E-pit-o-me/of good looks and grace/and quiet..uh..um..dignity\".", "The opportunity to pelt Susie with something having passed, Calvin threatens to turn Hobbes into a rug." ], [ "Books", "There are 18 ''Calvin and Hobbes'' books, published from 1987 to 1997.These include 11 collections, which form a complete archive of the newspaper strips, except for a single daily strip from November 28, 1985.", "(The collections ''do'' contain a strip for this date, but it is not the same strip that appeared in some newspapers.)", "Treasuries usually combine the two preceding collections with bonus material and include color reprints of Sunday comics.Watterson included some new material in the treasuries.", "In ''The Essential Calvin and Hobbes'', which includes cartoons from the collections ''Calvin and Hobbes'' and ''Something Under the Bed Is Drooling'', the back cover features a scene of a giant Calvin rampaging through a town.", "The scene is based on Watterson's home town of Chagrin Falls, Ohio, and Calvin is holding the Chagrin Falls Popcorn Shop, an iconic candy and ice cream shop overlooking the town's namesake falls.", "Several of the treasuries incorporate additional poetry; ''The Indispensable Calvin and Hobbes'' book features a set of poems, ranging from just a few lines to an entire page, that cover topics such as Calvin's mother's \"hindsight\" and exploring the woods.", "In ''The Essential Calvin and Hobbes'', Watterson presents a long poem explaining a night's battle against a monster from Calvin's perspective.", "''The Authoritative Calvin and Hobbes'' includes a story based on Calvin's use of the Transmogrifier to finish his reading homework.A complete collection of ''Calvin and Hobbes'' strips, in three hardcover volumes totaling 1440 pages, was released on October 4, 2005, by Andrews McMeel Publishing.", "It includes color prints of the art used on paperback covers, the treasuries' extra illustrated stories and poems and a new introduction by Bill Watterson in which he talks about his inspirations and his story leading up to the publication of the strip.", "The alternate 1985 strip is still omitted, and three other strips (January 7 and November 24, 1987, and November 25, 1988) have altered dialogue.", "A four-volume paperback version was released November 13, 2012.To celebrate the release (which coincided with the strip's 20th anniversary and the tenth anniversary of its absence from newspapers), Bill Watterson answered 15 questions submitted by readers.Early books were printed in smaller format in black and white.", "These were later reproduced in twos in color in the \"Treasuries\" (''Essential'', ''Authoritative'' and ''Indispensable''), except for the contents of ''Attack of the Deranged Mutant Killer Monster Snow Goons''.", "Those Sunday strips were not reprinted in color until the ''Complete'' collection was finally published in 2005.Watterson claims he named the books the \"''Essential'', ''Authoritative'' and ''Indispensable''\" because, as he says in ''The Calvin and Hobbes Tenth Anniversary Book'', the books are \"obviously none of these things.", "\"===''Teaching with Calvin and Hobbes''===''Teaching with Calvin and Hobbes''An officially licensed children's textbook entitled ''Teaching with Calvin and Hobbes'' was published in a single print run in Fargo, North Dakota, in 1993.The book is composed of ''Calvin and Hobbes'' strips that form story arcs, including \"The Binoculars\" and \"The Bug Collection\", followed by lessons based on the stories.The book is rare and highly sought.", "It has been called the \"Holy Grail\" for ''Calvin and Hobbes'' collectors." ], [ "Reception", "Reviewing ''Calvin and Hobbes'' in 1990, ''Entertainment Weekly'' Ken Tucker gave the strip an A+ rating, writing \"Watterson summons up the pain and confusion of childhood as much as he does its innocence and fun.", "\"===Academic response===In 1993, paleontologist and paleoartist Gregory S. Paul praised Bill Watterson for the scientific accuracy of the dinosaurs appearing in ''Calvin and Hobbes''.In her 1994 book ''When Toys Come Alive'', Lois Rostow Kuznets theorizes that Hobbes serves both as a figure of Calvin's childish fantasy life and as an outlet for the expression of libidinous desires more associated with adults.", "Kuznets also analyzes Calvin's other fantasies, suggesting that they are a second tier of fantasies utilized in places like school where transitional objects such as Hobbes would not be socially acceptable.Political scientist James Q. Wilson, in a paean to ''Calvin and Hobbes'' upon Watterson's decision to end the strip in 1995, characterized it as \"our only popular explication of the moral philosophy of Aristotle.", "\"Alisa White Coleman analyzed the strip's underlying messages concerning ethics and values in \"'Calvin and Hobbes': A Critique of Society's Values,\" published in the ''Journal of Mass Media Ethics'' in 2000.A collection of original Sunday strips was exhibited at Ohio State University's Billy Ireland Cartoon Library & Museum in 2001.Watterson himself selected the strips and provided his own commentary for the exhibition catalog, which was later published by Andrews McMeel as ''Calvin and Hobbes: Sunday Pages 1985–1995''.Since the discontinuation of ''Calvin and Hobbes'', individual strips have been licensed for reprint in schoolbooks, including the Christian homeschooling book ''The Fallacy Detective'' in 2002, and the university-level philosophy reader ''Open Questions: Readings for Critical Thinking and Writing'' in 2005; in the latter, the ethical views of Watterson and his characters Calvin and Hobbes are discussed in relation to the views of professional philosophers.", "In a 2009 evaluation of the entire body of ''Calvin and Hobbes'' strips using grounded theory methodology, Christijan D. Draper found that: \"Overall, ''Calvin and Hobbes'' suggests that meaningful time use is a key attribute of a life well lived,\" and that \"the strip suggests one way to assess the meaning associated with time use is through preemptive retrospection by which a person looks at current experiences through the lens of an anticipated future...\"Jamey Heit's ''Imagination and Meaning in Calvin and Hobbes'', a critical and academic analysis of the strip, was published in 2012.", "''Calvin and Hobbes'' strips were again exhibited at the Billy Ireland Cartoon Library & Museum at Ohio State University in 2014, in an exhibition entitled ''Exploring Calvin and Hobbes''.", "An exhibition catalog by the same title, which also contained an interview with Watterson conducted by Jenny Robb, the curator of the museum, was published by Andrews McMeel in 2015." ], [ "Legacy", "Years after its original newspaper run, ''Calvin and Hobbes'' has continued to exert influence in entertainment, art, and fandom.In television, Calvin and Hobbes have been satirically depicted in stop motion animation in the 2006 ''Robot Chicken'' episode \"Lust for Puppets,\" and in traditional animation in the 2009 ''Family Guy'' episode \"Not All Dogs Go to Heaven.\"", "In the 2013 ''Community'' episode \"Paranormal Parentage,\" the characters Abed Nadir (Danny Pudi) and Troy Barnes (Donald Glover) dress as Calvin and Hobbes, respectively, for Halloween.British artists, merchandisers, booksellers, and philosophers were interviewed for a 2009 BBC Radio 4 half-hour programme about the abiding popularity of the comic strip, narrated by Phill Jupitus.The first book-length study of the strip, ''Looking for Calvin and Hobbes: The Unconventional Story of Bill Watterson and His Revolutionary Comic Strip'' by Nevin Martell, was first published in 2009; an expanded edition was published in 2010.The book chronicles Martell's quest to tell the story of ''Calvin and Hobbes'' and Watterson through research and interviews with people connected to the cartoonist and his work.", "The director of the later documentary ''Dear Mr. Watterson'' referenced ''Looking for Calvin and Hobbes'' in discussing the production of the movie, and Martell appears in the film.The American documentary film ''Dear Mr. Watterson'', released in 2013, explores the impact and legacy of ''Calvin and Hobbes'' through interviews with authors, curators, historians, and numerous professional cartoonists.The enduring significance of ''Calvin and Hobbes'' to international cartooning was recognized by the jury of the Angoulême International Comics Festival in 2014 by the awarding of its Grand Prix to Watterson, only the fourth American to ever receive the honor (after Will Eisner, Robert Crumb, and Art Spiegelman).From 2016 to 2021, author Berkeley Breathed included ''Calvin and Hobbes'' in various ''Bloom County'' cartoons.", "He launched the first cartoon on April Fool's Day 2016 and jokingly issued a statement suggesting that he had acquired ''Calvin and Hobbes'' from Bill Watterson, who was \"out of the Arizona facility, continent and looking forward to some well-earned financial security.\"", "While bearing Watterson's signature and drawing style as well as featuring characters from both ''Calvin and Hobbes'' and Breathed's ''Bloom County'', it is unclear whether Watterson had any input into these cartoons or not.", "''Calvin and Hobbes'' remains the most viewed comic on GoComics, which cycles through old strips with an approximately 30-year delay.===Grown-up Calvin===Portraying Calvin as a teenager/adult has inspired writers.In 2011, a comic strip appeared by cartoonists Dan and Tom Heyerman called ''Hobbes and Bacon''.", "The strip depicts Calvin as an adult, married to Susie Derkins with a young daughter named after philosopher Francis Bacon, to whom Calvin gives Hobbes.", "Though consisting of only four strips originally, ''Hobbes and Bacon'' received considerable attention when it appeared and was continued by other cartoonists and artists.A novel titled ''Calvin'' by CLA Young Adult Book Award–winning author Martine Leavitt was published in 2015.The story tells of seventeen-year-old Calvin—who was born on the day that ''Calvin and Hobbes'' ended, and who has now been diagnosed with schizophrenia—and his hallucination of Hobbes, his childhood stuffed tiger.", "With his friend Susie, who might also be a hallucination, Calvin sets off to find Bill Watterson in the hope that the cartoonist can provide aid for Calvin's condition.The titular character of the comic strip ''Frazz'' has been noted for his similar appearance and personality to a grown-up Calvin.", "Creator Jef Mallett has stated that although Watterson is an inspiration to him, the similarities are unintentional." ], [ "References" ], [ "Bibliography", "******** ''Calvin and Hobbes'' at Don Markstein's Toonopedia.", "Archived from the original on April 13, 2012." ], [ "External links", "***" ] ]
wikipedia
[ [ "Campaign for Real Ale" ], [ "Introduction", "The '''Campaign for Real Ale''' ('''CAMRA''') is an independent voluntary consumer organisation headquartered in St Albans, England, which promotes real ale, cider and perry and traditional British pubs and clubs.", "With just under 150,000 members, it is the largest single-issue consumer group in the UK, and is a founding member of the European Beer Consumers Union (EBCU)." ], [ "History", "CAMRA logo on a bar towelFirst National CAMRA Beer Festival held at Covent Garden, London, 1975The organisation was founded on 16 March 1971 in Kruger's Bar, Dunquin, County Kerry, Ireland, by Michael Hardman, Graham Lees, Jim Makin, and Bill Mellor, who were opposed to the growing mass production of beer and the homogenisation of the British brewing industry.", "The original name was the Campaign for the Revitalisation of Ale.", "Following the formation of the Campaign, the first annual general meeting took place in 1972, at the Rose Inn in Coton Road, Nuneaton.", "Early membership consisted of the four founders and their friends.", "Interest in CAMRA and its objectives spread rapidly, with 5,000 members signed up by 1973.Other early influential members included Christopher Hutt, author of ''Death of the English Pub'', who succeeded Hardman as chairman, Frank Baillie, author of ''The Beer Drinker's Companion'', and later the many times ''Good Beer Guide'' editor, Roger Protz.In 1991, CAMRA reached 30,000 members across the UK and abroad and, a year later, helped to launch the European Beer Consumers Union.", "CAMRA remains EBCU's largest contributor, despite the UK's exit from the European Union.CAMRA published a history book on its 50th birthday, 16 March 2021, written by Laura Hadland ''50 Years of CAMRA''." ], [ "Aims", "CAMRA's stated aims are:# To secure the long-term future of real ale, real cider and real perry by increasing their quality, availability and popularity#To promote and protect pubs and clubs as social centres as part of the UK's cultural heritage#To increase recognition of the benefits of responsible, moderate social drinking#To play a leading role in the provision of information, education and training to all those with an interest in beer, cider and perry of any type#To ensure, where possible, that producers and retailers of beer, cider and perry act in the best interests of the customer.CAMRA's campaigns include promoting small brewing and pub businesses, reforming licensing laws, reducing tax on beer, and stopping continued consolidation among local British brewers.", "It also makes an effort to promote less common varieties of beer, including stout, porter, and mild, as well as traditional cider and perry.CAMRA's states that real ale should be served without the use of additional carbonation.", "This means that \"any beer brand which is produced in both cask and keg versions\" is not admitted to CAMRA festivals if the brewery's marketing is deemed to imply an equivalence of quality or character between the two versions." ], [ "Organisation", "The CAMRA office building in St AlbansCAMRA is organised on a federal basis, over 200 local branches, each covering a particular geographical area of the UK, that contribute to the central body of the organisation based in St Albans.", "It is governed by a National Executive, made up of 12 voluntary unpaid directors elected by the membership.", "The local branches are grouped into 16 regions across the UK, such as the West Midlands or Wessex.In 2009, CAMRA's membership reached 100,000, and 150,000 members in 2013." ], [ "Publications and websites", "CAMRA publishes the ''Good Beer Guide'', an annually compiled directory of the best 4,500 real ale outlets and listing of real ale brewers.CAMRA members received a monthly newspaper called ''What's Brewing'' until its April 2021 issue and there is a quarterly colour magazine called ''Beer''.", "It also maintains a National Inventory of Historic Pub Interiors to help bring greater recognition and protection to Britain's most historic pubs." ], [ "Festivals", "Great British Beer Festival 2004CAMRA supports and promotes beer and cider festivals around the country, which are organised by local CAMRA branches.", "Generally, each festival charges an entry fee which either covers entry only or also includes a commemorative glass showing the details of the festival.", "A festival programme is usually also provided, with a list and description of the drinks available.", "Members may get discounted entrance to CAMRA festivals.The Campaign also organises the annual Great British Beer Festival in August.", "It is now held in the Great, National & West Halls at the Olympia Exhibition Centre, in Kensington, London, having been held for a few years at Earl's Court as well as regionally in the past at venues such as Brighton and Leeds.", "This is the UK's largest beer festival, with over 900 beers, ciders and perries available over the week long event.For many years, CAMRA also organised the National Winter Ales Festival.", "However, in 2017 this was re-branded as the Great British Beer Festival Winter where they award the Champion Winter Beer of Britain.", "Unlike the Great British Beer Festival, the Winter event does not have a permanent venue and is rotated throughout the country every three years.", "Recent hosts have been Derby and Norwich, with the event currently held each February in Birmingham.", "In 2020 CAMRA also launched the Great Welsh Beer Festival, to be held in Cardiff in April." ], [ "Awards", "CAMRA presents awards for beers and pubs, such as the National Pub of the Year.", "The competition begins in the preceding year with branches choosing their local pub of the year through either a ballot or a panel of judges.", "The branch winners are entered into 16 regional competitions which are then visited by several individuals who agree the best using a scoring system that looks at beer quality, aesthetic, and welcome.", "The four finalists are announced each year before a ceremony to crown the winner in the spring.", "There are also the Pub Design Awards, which are held in association with English Heritage and the Victorian Society.", "These comprise several categories, including new build, refurbished and converted pubs.The best known CAMRA award is the Champion Beer of Britain, which is selected at the Great British Beer Festival.", "Other awards include the Champion Beer of Scotland and the Champion Beer of Wales." ], [ "National Beer Scoring Scheme", "CAMRA developed the National Beer Scoring Scheme (NBSS) as an easy to use scheme for judging beer quality in pubs, to assist CAMRA branches in selecting pubs for the ''Good Beer Guide''.", "CAMRA members input their beer scores online via WhatPub or through the Good Beer Guide app." ], [ "Pub heritage", "The CAMRA Pub Heritage Group identifies, records and helps to protect pub interiors of historic and/or architectural importance, and seeks to get them listed.The group maintains two inventories of Heritage pubs, the National Inventory (NI), which contains only those pubs that have been maintained in their original condition (or have been modified very little) for at least thirty years, but usually since at least World War II.", "The second, larger, inventory is the Regional Inventory (RI), which is broken down by county and contains both those pubs listed in the NI and other pubs that are not eligible for the NI, for reasons such as having been overly modified, but are still considered historically important, or have particular architectural value." ], [ "LocAle", "The LocAle scheme was launched in 2007 to promote locally brewed beers.", "The scheme functions slightly differently in each area, and is managed by each branch, but each is similar: if the beer is to be promoted as a LocAle it must come from a brewery within a predetermined number of miles set by each CAMRA branch, generally around 20, although the North London branch has set it at 30 miles from brewery to pub, even if it comes from a distribution centre further away; in addition, each participating pub must keep at least one LocAle for sale at all times." ], [ "Investment club", "CAMRA members may join the CAMRA Members' Investment Club which, since 1989, has invested in real ale breweries and pub chains.", "As of January 2021 the club had over 3,000 members and owned investments worth over £17 million.", "Although all investors must be CAMRA members, the CAMRA Members' Investment Club is not part of CAMRA Ltd." ], [ "See also", "*Society for the Preservation of Beers from the Wood*Society of Independent Brewers*Independent Family Brewers of Britain*European Beer Consumers' Union*Real Ale Twats" ], [ "References" ], [ "External links", "* CAMRA website** Pub Heritage Group – Official Site* Great British Beer Festival" ] ]
wikipedia
[ [ "CNO cycle" ], [ "Introduction", "Logarithm of the relative energy output (ε) of proton–proton (p–p), CNO, and triple-α fusion processes at different temperatures (T).", "The dashed line shows the combined energy generation of the p–p and CNO processes within a star.The '''CNO cycle''' (for carbon–nitrogen–oxygen; sometimes called '''Bethe–Weizsäcker cycle''' after Hans Albrecht Bethe and Carl Friedrich von Weizsäcker) is one of the two known sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton–proton chain reaction (p–p cycle), which is more efficient at the Sun's core temperature.", "The CNO cycle is hypothesized to be dominant in stars that are more than 1.3 times as massive as the Sun.Unlike the proton-proton reaction, which consumes all its constituents, the CNO cycle is a catalytic cycle.", "In the CNO cycle, four protons fuse, using carbon, nitrogen, and oxygen isotopes as catalysts, each of which is consumed at one step of the CNO cycle, but re-generated in a later step.", "The end product is one alpha particle (a stable helium nucleus), two positrons, and two electron neutrinos.There are various alternative paths and catalysts involved in the CNO cycles, but all these cycles have the same net result::4   +   2 ::   →     +     +   ::   →     +     +   The positrons will almost instantly annihilate with electrons, releasing energy in the form of gamma rays.", "The neutrinos escape from the star carrying away some energy.", "One nucleus goes on to become carbon, nitrogen, and oxygen isotopes through a number of transformations in a repeating cycle.Overview of the CNO-I CycleThe proton–proton chain is more prominent in stars the mass of the Sun or less.", "This difference stems from temperature dependency differences between the two reactions; pp-chain reaction starts at temperatures around (4 megakelvin), making it the dominant energy source in smaller stars.", "A self-maintaining CNO chain starts at approximately , but its energy output rises much more rapidly with increasing temperatures so that it becomes the dominant source of energy at approximately .The Sun has a core temperature of around , and only of nuclei produced in the Sun areborn in the CNO cycle.The CNO-I process was independently proposed by Carl von Weizsäcker and Hans Bethe in the late 1930s.The first reports of the experimental detection of the neutrinos produced by the CNO cycle in the Sun were published in 2020 by the BOREXINO collaboration.", "This was also the first experimental confirmation that the Sun had a CNO cycle, that the proposed magnitude of the cycle was accurate, and that von Weizsäcker and Bethe were correct." ], [ "Cold CNO cycles", "Under typical conditions found in stars, catalytic hydrogen burning by the CNO cycles is limited by proton captures.", "Specifically, the timescale for beta decay of the radioactive nuclei produced is faster than the timescale for fusion.", "Because of the long timescales involved, the cold CNO cycles convert hydrogen to helium slowly, allowing them to power stars in quiescent equilibrium for many years.=== CNO-I ===The first proposed catalytic cycle for the conversion of hydrogen into helium was initially called the carbon–nitrogen cycle (CN-cycle), also referred to as the Bethe–Weizsäcker cycle in honor of the independent work of Carl Friedrich von Weizsäcker in 1937–38 and Hans Bethe.", "Bethe's 1939 papers on the CN-cycle drew on three earlier papers written in collaboration with Robert Bacher and Milton Stanley Livingston and which came to be known informally as ''\"Bethe's Bible\"''.", "It was considered the standard work on nuclear physics for many years and was a significant factor in his being awarded the 1967 Nobel Prize in Physics.", "Bethe's original calculations suggested the CN-cycle was the Sun's primary source of energy.", "This conclusion arose from a belief that is now known to be mistaken, that the abundance of nitrogen in the sun is approximately 10%; it is actually less than half a percent.", "The CN-cycle, named as it contains no stable isotope of oxygen, involves the following cycle of transformations::   →     →     →     →     →     →   This cycle is now understood as being the first part of a larger process, the CNO-cycle, and the main reactions in this part of the cycle (CNO-I) are: : +  →  +    +    →  +  +  +  (half-life of 9.965 minutes) +  →  +    +  +  →  +    +    →  +  +  (half-life of 122.24 seconds) +  →  +    + where the carbon-12 nucleus used in the first reaction is regenerated in the last reaction.", "After the two positrons emitted annihilate with two ambient electrons producing an additional , the total energy released in one cycle is 26.73 MeV; in some texts, authors are erroneously including the positron annihilation energy in with the beta-decay Q-value and then neglecting the equal amount of energy released by annihilation, leading to possible confusion.", "All values are calculated with reference to the Atomic Mass Evaluation 2003.The limiting (slowest) reaction in the CNO-I cycle is the proton capture on .", "In 2006 it was experimentally measured down to stellar energies, revising the calculated age of globular clusters by around 1 billion years.The neutrinos emitted in beta decay will have a spectrum of energy ranges, because although momentum is conserved, the momentum can be shared in any way between the positron and neutrino, with either emitted at rest and the other taking away the full energy, or anything in between, so long as all the energy from the Q-value is used.", "The total momentum received by the positron and the neutrino is not great enough to cause a significant recoil of the much heavier daughter nucleus and hence, its contribution to kinetic energy of the products, for the precision of values given here, can be neglected.", "Thus the neutrino emitted during the decay of nitrogen-13 can have an energy from zero up to , and the neutrino emitted during the decay of oxygen-15 can have an energy from zero up to .", "On average, about 1.7 MeV of the total energy output is taken away by neutrinos for each loop of the cycle, leaving about available for producing luminosity.=== CNO-II ===In a minor branch of the above reaction, occurring in the Sun's core 0.04% of the time, the final reaction involving shown above does not produce carbon-12 and an alpha particle, but instead produces oxygen-16 and a photon and continues:In detail:: +  →  +    +  +  →  +    +    →  +  +  (half-life of 64.49 seconds) +  →  +    +  +  →  +    +    →  +  +  (half-life of 122.24 seconds)Like the carbon, nitrogen, and oxygen involved in the main branch, the fluorine produced in the minor branch is merely an intermediate product; at steady state, it does not accumulate in the star.=== CNO-III ===This subdominant branch is significant only for massive stars.", "The reactions are started when one of the reactions in CNO-II results in fluorine-18 and a photon instead of nitrogen-14 and an alpha particle, and continues: → → → → → → In detail::  +     →     +         +         →     +     +     +   (half-life of )   +     →     +         +     +     →     +         +     +     →     +         +         →     +     +     +   (half-life of )=== CNO-IV ===A proton reacts with a nucleus causing release of an alpha particle.Like the CNO-III, this branch is also only significant in massive stars.", "The reactions are started when one of the reactions in CNO-III results in fluorine-19 and a photon instead of nitrogen-15 and an alpha particle, and continues:In detail::  +  →   +     +  +  →  +    +  +  →  +    +    →  +  +  (half-life of 64.49 seconds) +  →  +    +    →  +  +  (half-life of 109.771 minutes)In some instances can combine with a helium nucleus to start a sodium-neon cycle." ], [ "Hot CNO cycles", "Under conditions of higher temperature and pressure, such as those found in novae and X-ray bursts, the rate of proton captures exceeds the rate of beta-decay, pushing the burning to the proton drip line.", "The essential idea is that a radioactive species will capture a proton before it can beta decay, opening new nuclear burning pathways that are otherwise inaccessible.", "Because of the higher temperatures involved, these catalytic cycles are typically referred to as the hot CNO cycles; because the timescales are limited by beta decays instead of proton captures, they are also called the beta-limited CNO cycles.=== HCNO-I ===The difference between the CNO-I cycle and the HCNO-I cycle is that captures a proton instead of decaying, leading to the total sequence:→→→→→→In detail:: +  →  +    +  +  →  +    +    →  +  +  (half-life of 70.641 seconds) +  →  +    +    →  +  +  (half-life of 122.24 seconds) +  →  +    + === HCNO-II ===The notable difference between the CNO-II cycle and the HCNO-II cycle is that captures a proton instead of decaying, and neon is produced in a subsequent reaction on , leading to the total sequence:→→→→→→In detail:: +  →  +    +  +  →  +    +  +  →  +    +    →  +  +  (half-life of 1.672 seconds) +  →  +    +    →  +  +  (half-life of 122.24 seconds)=== HCNO-III ===An alternative to the HCNO-II cycle is that captures a proton moving towards higher mass and using the same helium production mechanism as the CNO-IV cycle as:→→→→→→In detail:: +  →  +    +    →  +  +  (half-life of 17.22 seconds) +  →  +    +  +  →  +    +  +  →  +    +    →  +  +  (half-life of 1.672 seconds)" ], [ "Use in astronomy", "While the total number of \"catalytic\" nuclei are conserved in the cycle, in stellar evolution the relative proportions of the nuclei are altered.", "When the cycle is run to equilibrium, the ratio of the carbon-12/carbon-13 nuclei is driven to 3.5, and nitrogen-14 becomes the most numerous nucleus, regardless of initial composition.", "During a star's evolution, convective mixing episodes moves material, within which the CNO cycle has operated, from the star's interior to the surface, altering the observed composition of the star.", "Red giant stars are observed to have lower carbon-12/carbon-13 and carbon-12/nitrogen-14 ratios than do main sequence stars, which is considered to be convincing evidence for the operation of the CNO cycle." ], [ "See also", "* Aneutronic fusion* Cold fusion* Fusion power* Nuclear fusion* Proton–proton chain, as found in stars like the Sun* Stellar nucleosynthesis, the whole topic* Triple-alpha process, how is produced from lighter nuclei" ], [ "Footnotes" ], [ "References" ], [ "Further reading", "* *" ] ]
wikipedia
[ [ "Craps" ], [ "Introduction", "'''Craps''' is a dice game in which players bet on the outcomes of the roll of a pair of dice.", "Players can wager money against each other (playing \"street craps\") or against a bank (\"casino craps\").", "Because it requires little equipment, \"street craps\" can be played in informal settings.", "While shooting craps, players may use slang terminology to place bets and actions." ], [ "History", "Craps game at a military camp in 1918Craps being played by children in a street in St Louis, Missouri, circa 1912In 1788, \"Krabs\" (later spelled crabs) was an English variation on the dice game hazard (also spelled hasard).Craps developed in the United States from a simplification of the western European game of hazard.", "The origins of hazard are obscure and may date to the Crusades.", "Hazard was brought from London to New Orleans in approximately 1805 by the returning Bernard Xavier Philippe de Marigny de Mandeville, the young gambler and scion of a family of wealthy landowners in colonial Louisiana.", "Although in hazard the dice shooter may choose any number from five to nine to be his main number, de Marigny simplified the game such that the main number is always seven, which is the mathematically optimal choice (choice with the lowest disadvantage for the shooter).", "Both hazard and its simpler derivative were unfamiliar to and rejected by Americans of his social class, leading de Marigny to introduce his novelty to the local underclass.", "Field hands taught their friends and deckhands, who carried the new game up the Mississippi River and its tributaries.", "Celebrating the popular success of his novelty, de Marigny gave the name Rue de Craps to a street in his new subdivision in New Orleans.The central game, called pass from the French word ''pas'' (meaning \"pace\" or \"step\"), has been gradually supplemented over the decades by many companion games which can be played simultaneously with pass.", "Now applied to the entire collection of games, the name craps derives from an underclass Louisiana mispronunciation of the word ''crabs'', which in aristocratic London had been the epithet for the numbers two and three.", "In hazard, both \"crabs\" are always instant-losing numbers for the first dice roll regardless of the shooter's selected main number.", "Also in hazard, if the main number is seven then the number twelve is added to the crabs as a losing number on the first dice roll.", "This structure is retained in the simplified game called pass.", "All three losing numbers on the first roll of pass are jointly called the craps numbers.For a century after its invention, casinos used unfair dice.", "In approximately 1907, a dicemaker named John H. Winn in Philadelphia introduced a layout which featured bets on Don't Pass as well as Pass.", "Virtually all modern casinos use his innovation, which incentivizes casinos to use fair dice.Craps exploded in popularity during World War II, which brought most young American men of every social class into the military.", "The street version of craps was popular among service members who often played it using a blanket as a shooting surface.", "Their military memories led to craps becoming the dominant casino game in postwar Las Vegas and the Caribbean.", "After 1960, a few casinos in Europe, Australia, and Macau began offering craps, and, after 2004, online casinos extended the game's spread globally." ], [ "Bank craps", "Bank craps or casino craps is played by one or more players betting against the casino rather than each other.", "Both the players and the dealers stand around a large rectangular craps table.", "Sitting is discouraged by most casinos unless a player has medical reasons for requiring a seat.===Craps table===The layout of a craps tablePlayers use casino chips rather than cash to bet on the Craps \"layout\", a fabric surface which displays the various bets.", "The bets vary somewhat among casinos in availability, locations, and payouts.", "The tables roughly resemble bathtubs and come in various sizes.", "In some locations, chips may be called checks, tokens, or plaques.Against one long side is the casino's table bank: as many as two thousand casino chips in stacks of 20.The opposite long side is usually a long mirror.", "The U-shaped ends of the table have duplicate layouts and standing room for approximately eight players.", "In the center of the layout is an additional group of bets which are used by players from both ends.", "The vertical walls at each end are usually covered with a rubberized target surface covered with small pyramid shapes to randomize the dice which strike them.", "The top edges of the table walls have one or two horizontal grooves in which players may store their reserve chips.The table is run by up to four casino employees: a '''''boxman''''' seated (usually the only seated employee) behind the casino's bank, who manages the chips, supervises the dealers, and handles \"coloring up\" players (exchanging small chip denominations for larger denominations in order to preserve the chips at a table); two '''''base dealers''''' who stand to either side of the boxman and collect and pay bets to players around their half of the table; and a '''''stickman''''' who stands directly across the table from the boxman, takes and pays (or directs the base dealers to do so) the bets in the center of the table, announces the results of each roll (usually with a distinctive patter), and moves the dice across the layout with an elongated wooden stick.Each employee also watches for mistakes by the others because of the sometimes large number of bets and frantic pace of the game.", "In smaller casinos or at quiet times of day, one or more of these employees may be missing, and have their job covered by another, or cause player capacity to be reduced.Some smaller casinos have introduced \"mini-craps\" tables which are operated with only two dealers; rather than being two essentially identical sides and the center area, a single set of major bets is presented, split by the center bets.", "Responsibility of the dealers is adjusted: while the stickman continues to handle the center bets, it is the base dealer who handles all other bets (as well as cash and chip exchanges).By contrast, in \"street craps\", there is no marked table and often the game is played with no back-stop against which the dice are to hit.", "(Despite the name \"street craps\", this game is often played in houses, usually on an un-carpeted garage or kitchen floor.)", "The wagers are made in cash, never in chips, and are usually thrown down onto the ground or floor by the players.", "There are no attendants, and so the progress of the game, fairness of the throws, and the way that the payouts are made for winning bets are self-policed by the players.===Rules of play===Each casino may set which bets are offered and different payouts for them, though a core set of bets and payouts is typical.", "Players take turns rolling two dice and whoever is throwing the dice is called the \"shooter\".", "Players can bet on the various options by placing chips directly on the appropriately-marked sections of the layout, or asking the base dealer or stickman to do so, depending on which bet is being made.While acting as the shooter, a player must have a bet on the \"Pass\" line and/or the \"Don't Pass\" line.", "\"Pass\" and \"Don't Pass\" are sometimes called \"Win\" and \"Don't Win\" or \"Right\" and \"Wrong\" bets.", "The game is played in rounds and these \"Pass\" and \"Don't Pass\" bets are betting on the outcome of a round.", "The shooter is presented with multiple dice (typically five) by the \"stickman\", and must choose two for the round.", "The remaining dice are returned to the stickman's bowl and are not used.A roll of 11 in the come-out phase is a \"natural\".Each round has two phases: \"come-out\" and \"point\".", "Dice are passed to the left.", "To start a round, the shooter makes one or more \"come-out\" rolls.", "The shooter must shoot toward the farther back wall and is generally required to hit the farther back wall with both dice.", "Casinos may allow a few warnings before enforcing the dice to hit the back wall and are generally lenient if at least one die hits the back wall.", "Both dice must be tossed in one throw.", "If only one die is thrown the shot is invalid.", "A come-out roll of 2, 3, or 12 is called \"craps\" or \"crapping out\", and anyone betting the Pass line loses.", "On the other hand, anyone betting the Don't Pass line on come out wins with a roll of 2 or 3 and ties (pushes) if a 12 is rolled.", "Shooters may keep rolling after crapping out; the dice are only required to be passed if a shooter sevens out (rolls a seven after a point has been established).", "A come-out roll of 7 or 11 is a \"natural\"; the Pass line wins and Don't Pass loses.", "The other possible numbers are the point numbers: 4, 5, 6, 8, 9, and 10.If the shooter rolls one of these numbers on the come-out roll, this establishes the \"point\" – to \"pass\" or \"win\", the point number must be rolled again before a seven.The dealer flips a button to the \"On\" side and moves it to the point number signifying the second phase of the round.", "If the shooter \"hits\" the point value again (any value of the dice that sum to the point will do; the shooter doesn't have to exactly repeat the exact combination of the come-out roll) before rolling a seven, the Pass line wins and a new round starts.", "If the shooter rolls any seven before repeating the point number (a \"seven-out\"), the Pass line loses, the Don't Pass line wins, and the dice pass clockwise to the next new shooter for the next round.", "Once a point has been established any multi-roll bet (including Pass and/or Don't Pass line bets and odds) are unaffected by the 2, 3, 11, or 12; the only numbers which affect the round are the established point, any specific bet on a number, or any 7.Any single roll bet is always affected (win or lose) by the outcome of any roll.While the come-out roll may specifically refer to the first roll of a new shooter, any roll where no point is established may be referred to as a come-out.", "By this definition the start of any new round regardless if it is the shooter's first toss can be referred to as a come-out roll.Any player can make a bet on Pass or Don't Pass as long as a point has not been established, or Come or Don't Come as long as a point is established.", "All other bets, including an increase in odds behind the Pass and Don't Pass lines, may be made at any time.", "All bets other than Pass line and Come may be removed or reduced any time before the bet loses.", "This is known as \"taking it down\" in craps.The maximum bet for Place, Buy, Lay, Pass, and Come bets are generally equal to table maximum.", "Lay bet maximum are equal to the table maximum win, so players wishing to lay the 4 or 10 may bet twice at amount of the table maximum for the win to be table maximum.", "Odds behind Pass, Come, Don't Pass, and Don't Come may be however larger than the odds offered allows and can be greater than the table maximum in some casinos.", "Don't odds are capped on the maximum allowed win some casino allow the odds bet itself to be larger than the maximum bet allowed as long as the win is capped at maximum odds.", "Single rolls bets can be lower than the table minimum, but the maximum bet allowed is also lower than the table maximum.", "The maximum allowed single roll bet is based on the maximum allowed win from a single roll.In all the above scenarios, whenever the Pass line wins, the Don't Pass line loses, and vice versa, with one exception: on the come-out roll, a roll of 12 will cause Pass Line bets to lose, but Don't Pass bets are pushed (or \"barred\"), neither winning nor losing.", "(The same applies to \"Come\" and \"Don't Come\" bets, discussed below.", ")===Joining a game===A player wishing to play craps without being the shooter should approach the craps table and first check to see if the dealer's \"On\" button is on any of the point numbers.", "* If the button has been turned to \"Off\", then the table is in the come-out round, and a point has not been established.", "* If the dealer's button is \"On\", the table is in the point round where casinos will allow odds behind an existing Pass line to be bet.", "Some casino do not allow new Pass line bets while a point has been established.", "Some casinos will place the bet straddling the outer border of the Pass line so as to indicate that it is to be paid the same odds as a place bet, instead of just even money.", "Other casinos will take the bet on the Pass line after a point has been established, known as put betting, which is a disadvantage to the player (since the seven is the most common roll and likely to happen before the \"point\").In either case, all single or multi-roll proposition bets may be placed in either of the two rounds.Between dice rolls there is a period for dealers to make payouts and collect losing bets, after which players can place new bets.", "The stickman monitors the action at a table and decides when to give the shooter the dice, after which no more betting is allowed.When joining the game, one should place money on the table rather than passing it directly to a dealer.", "The dealer's exaggerated movements during the process of \"making change\" or \"change only\" (converting currency to an equivalent in casino cheques) are required so that any disputes can be later reviewed against security camera footage.===Rolling===The dealers will insist that the shooter roll with one hand and that the dice bounce off the far wall surrounding the table.", "These requirements are meant to keep the game fair (preventing switching the dice or making a \"controlled shot\").", "If a die leaves the table, the shooter will usually be asked to select another die from the remaining three but can request permission to use the same die if it passes the boxman's inspection.", "This requirement exists to keep the game fair and reduce the chance of loaded dice.===Names of rolls===+ Names of Rolls in Craps Snake Eyes Ace Deuce Hard Four Easy Four Five (Fever Five) Hard Six Five (Fever Five) Easy Six Natural/Seven Out Hard Eight Easy Six Natural/Seven Out Easy Eight Nine (Nina) Hard Ten Natural or Seven Out Easy Eight Nine (Nina) Easy Ten Yo (Yo-leven) Boxcars/MidnightThere are many local variants of the calls made by the stickman for rolls during a craps game.", "These frequently incorporate a reminder to the dealers as to which bets to pay or collect.", "* Two is \"snake eyes\", because the two ones that compose it look like a pair of small, beady eyes.", "During actual play, more common terms are \"two craps two\" during the comeout roll because the Pass line bet is lost on a comeout crap roll and/or because a bet on any craps would win.", "\"Aces; double the field\" would be a more common call when not on the comeout roll to remind the dealers to pay double on the field bets and encourage the field bettor to place subsequent bets and/or when no crap bets have been placed.", "Another name for the two is \"loose deuce\" or \"Snickies\" due to it sounding like \"Snake eyes\" but spoken with an accent.", "* Three is typically called as \"three craps three\" during the comeout roll, or \"three, ace deuce, come away single\" when not on the comeout to signify the come bet has been lost and to pay single to any field bettors.", "Three may also be referred to as \"ace caught a deuce\", \"Tracy\", or even less often \"acey deucey\".", "* Four, usually hard, is sometimes referred to as \"Little Joe from Kokomo\" or \"Little Joe on the front row\" or just \"Little Joe\".", "A hard four can be called a \"ballerina\" because it is two-two (\"tutu\").", "* Five is frequently called \"no field five\" in casinos in which five is not one of the field rolls and thus not paid in the field bets.", "Other names for a five are \"fever\" and \"little Phoebe\".", "* Six may be referred to as \"Jimmie Hicks\" or \"Jimmie Hicks from the sticks\", examples of rhyming slang.", "On a win, the six is often called \"666 winner 6\" followed by \"came hard\" or \"came easy\".", "* Seven rolled as 6–1 is sometimes called \"six ace\" or \"up pops the Devil\".", "Older dealers and players may use the term \"Big Red\" because craps tables once prominently featured a large red \"7\" in the center of the layout for the one-roll seven bet.", "During the comeout, the seven is called \"seven, front line winner\", frequently followed by \"pay the line\" and/or \"take the don'ts\".", "After the point is established, a seven is typically called by simply \"7 out\" or \"7 out 7\"..*Eight rolled the hard way, as opposed to an \"easy eight\", is sometimes called an \"eighter from Decatur\".", "It can also be known as a \"square pair\", \"mom and dad\", or \"Ozzie and Harriet\".", "* Nine is called a \"centerfield nine\" in casinos in which nine is one of the field rolls, because nine is the center number shown on the layout in such casinos (2–3–4–9–10–11–12).", "In Atlantic City, a 4–5 is called a \"railroad nine\".", "The 4–5 nine is also known as \"Jesse James\" because the outlaw Jesse James was killed by a .45 caliber pistol.", "Other names for the nine include \"Nina from Pasadena\", \"Nina at the Marina\", and \"niner from Carolina\".", "Nine can also be referred to as \"Old Mike\", named after NBA Hall-of-Famer Michael Jordan, who wore No.", "9 in his FIBA international career, when players could only wear numbers 4 to 15.", "*Ten the hard way is \"a hard ten\", \"dos equis\" (Spanish, meaning \"two X's\", because the pip arrangement on both dice on this roll resembles \"XX\"), or \"Hard ten – a woman's best friend\", an example of both rhyming slang and sexual double entendre.", "Ten as a pair of 5's may also be known as \"puppy paws\" or \"a pair of sunflowers\" or \"Big Dick\" or \"Big John.\"", "Another slang for a hard ten is \"moose head\", because it resembles a moose's antlers.", "This phrase came from players in the Pittsburgh area.", "*Eleven is called out as \"yo\" or \"yo-leven\" to prevent being misheard as \"seven\".", "An older term for eleven is \"six five, no jive\" because it is a winning roll.", "During the comeout, eleven is typically followed by \"front line winner\".", "After the point is established, \"good field and come\" is often added.", "*Twelve is known as \"boxcars\" because the spots on the two dice that show 6–6 look like schematic drawings of railroad boxcars; it is also called \"midnight\", referring to twelve o'clock; and also as \"double-action field traction\", because of the (standard) 2-to-1 pay on Field bets for this roll and the fact that the arrangement of the pips on the two dice, when laid end-to-end, resemble tire tracks.", "On tables that pay triple the field on a twelve roll, the stickman will often loudly exclaim \"triple\" either alone or in combination with \"12 craps 12\" or \"come away triple\".Rolls of 4, 6, 8, and 10 are called \"hard\" or \"easy\" (e.g.", "\"six the hard way\", \"easy eight\", \"hard ten\") depending on whether they were rolled as a \"double\" or as any other combination of values, because of their significance in center table bets known as the \"hard ways\".", "Hard way rolls are so named because there is only one way to roll them (i.e., the value on each die is the same when the number is rolled).", "Consequently, it is more likely to roll the number in combinations (easy) rather than as a double (hard)." ], [ "Types of wagers", "A standard craps table===Line bets===The shooter is required to make either a Pass line bet or a Don't Pass bet if he wants to shoot.", "On the come out roll each player may only make one bet on the Pass or Don't Pass, but may bet both if desired.", "The Pass Line and Don't Pass bet is optional for any player not shooting.", "In rare cases, some casinos require all players to make a minimum Pass Line or Don't Pass bet (if they want to make any other bet), whether they are currently shooting or not.====Pass line====The fundamental bet in craps is the Pass line bet, which is a bet for the shooter to win.", "This bet must be at least the table minimum and at most the table maximum.", "* If the come-out roll is 7 or 11, the bet wins.", "* If the come-out roll is 2, 3 or 12, the bet loses (known as \"crapping out\").", "* If the roll is any other value, it establishes a point.", "** If, with a point established, that point is rolled again before a 7, the bet wins.", "** If, with a point established, a 7 is rolled before the point is rolled again (\"seven out\"), the bet loses.The Pass line bet pays even money.The Pass line bet is a contract bet.", "Once a Pass line bet is made, it is always working and cannot be turned \"Off\", taken down, or reduced until a decision is reached – the point is made, or the shooter sevens out.", "A player may increase any corresponding odds (up to the table limit) behind the Pass line at any time after a point is established.", "Players may only bet the Pass line on the come out roll when no point has been established, unless the casino allows put betting where the player can bet Pass line or increase an existing Pass line bet whenever desired and may take odds immediately if the point is already on.====Don't Pass====A Don't Pass bet is a bet for the shooter to lose (\"seven out, line away\") and is almost the opposite of the Pass line bet.", "Like the Pass bet, this bet must be at least the table minimum and at most the table maximum.", "* If the come-out roll is 2 or 3, the bet wins.", "* If the come-out roll is 7 or 11, the bet loses.", "* If the come-out roll is 12, the bet is a push (neither won nor lost).", "In some casinos, the bet pushes on 2 and wins on 12 instead.", "Others allow the player to choose to either push on 2 (\"Bar Aces\") or push on 12 (\"Bar Sixes\") depending on where it is placed on the layout.", "The push on 12 or 2 is mathematically necessary to maintain the house edge over the player.", "* If the roll is any other value, it establishes a point.", "** If, with a point established, a 7 is rolled before the point is rolled again (\"seven out\"), the bet wins.", "** If, with a point established, that point is rolled again before a 7, the bet loses.The Don't Pass bet pays even money.The Don't Pass bet is a no-contract bet.", "After a point is established, a player may take down or reduce a Don't Pass bet and any corresponding odds at any time because odds of rolling a 7 before the point is in the player's favor.", "Once taken down or reduced, however, the Don't Pass bet may not be restored or increased.", "Because the shooter must have a line bet the shooter generally may not reduce a Don't Pass bet below the table minimum.", "In Las Vegas, a majority of casinos will allow the shooter to move the bet to the Pass line in lieu of taking it down; however, in other areas such as Pennsylvania and Atlantic City, this is not allowed.", "Even though players are allowed to remove the Don't Pass line bet after a point has been established, the bet cannot be turned \"Off\" without being removed.", "If a player chooses to remove the Don't Pass line bet, he or she can no longer lay odds behind the Don't Pass line.", "The player can, however, still make standard lay bets on any of the point numbers (4, 5, 6, 8, 9, 10).There are two different ways to calculate the odds and house edge of this bet.", "The table below gives the numbers considering that the game ends in a push when a 12 is rolled, rather than being undetermined.", "Betting on Don't Pass is often called \"playing the dark side\", and it is considered by some players to be in poor taste, or even taboo, because it goes directly against conventional play, winning when most of the players lose.====Pass odds====If a 4, 5, 6, 8, 9, or 10 is thrown on the come-out roll (i.e., if a point is established), most casinos allow Pass line players to take odds by placing up to some predetermined multiple of the Pass line bet, behind the Pass line.", "This additional bet wins if the point is rolled again before a 7 is rolled (the point is made) and pays at the true odds of 2-to-1 if 4 or 10 is the point, 3-to-2 if 5 or 9 is the point, or 6-to-5 if 6 or 8 is the point.", "Unlike the Pass line bet itself, the Pass line odds bet can be turned \"Off\" (not working), removed or reduced anytime before it loses.", "In Las Vegas, generally odds bets are required to be the table minimum.", "In Atlantic City and Pennsylvania, the combine odds and Pass bet must be table minimum so players can bet the minimum single unit on odds depending on the point.", "If the point is a 4 or 10 players can bet as little as $1 on odds if the table minimum is low such as is $5, $10 or $15.If the player requests the Pass odds be not working (\"Off\") and the shooter sevens-out or hits the point, the Pass line bet will be lost or doubled and the Pass odds returned.Individual casinos (and sometimes tables within a casino) vary greatly in the maximum odds they offer, from single or double odds (one or two times the Pass line bet) up to 100x or even unlimited odds.", "A variation often seen is \"3-4-5X Odds\", where the maximum allowed odds bet depends on the point: three times if the point is 4 or 10; four times on points of 5 or 9; or five times on points of 6 or 8.This rule simplifies the calculation of winnings: a maximum Pass odds bet on a 3–4–5× table will always be paid at six times the Pass line bet regardless of the point.As odds bets are paid at true odds, in contrast with the Pass line which is always even money, taking odds on a minimum Pass line bet lessens the house advantage compared with betting the same total amount on the Pass line only.", "A maximum odds bet on a minimum Pass line bet often gives the lowest house edge available in any game in the casino.", "However, the odds bet cannot be made independently, so the house retains an edge on the Pass line bet itself.====Don't Pass odds====If a player is playing Don't Pass instead of pass, they may also lay odds by placing chips behind the Don't Pass line.", "If a 7 comes before the point is rolled, the odds pay at true odds of 1-to-2 if 4 or 10 is the point, 2-to-3 if 5 or 9 is the point, or 5-to-6 if 6 or 8 is the point.", "Typically the maximum lay bet will be expressed such that a player may win up to an amount equal to the maximum odds multiple at the table.", "If a player lays maximum odds with a point of 4 or 10 on a table offering five-times odds, he would be able to lay a maximum of ten times the amount of his Don't Pass bet.", "At 5x odds table, the maximum amount the combined bet can win will always be 6x the amount of the Don't Pass bet.", "Players can bet table minimum odds if desired and win less than table minimum.", "Like the Don't Pass bet the odds can be removed or reduced.", "Unlike the Don't Pass bet itself, the Don't Pass odds can be turned \"Off\" (not working).", "In Las Vegas generally odds bets are required to be the table minimum.", "In Atlantic City and Pennsylvania, the combine lay odds and Don't Pass bet must be table minimum so players may bet as little as the minimum two units on odds depending on the point.", "If the point is a 4 or 10 players can bet as little as $2 if the table minimum is low such as $5, $10 or $15 tables.", "If the player requests the Don't Pass odds to be not working (\"Off\") and the shooter hits the point or sevens-out, the Don't Pass bet will be lost or doubled and the Don't Pass odds returned.", "Unlike a standard lay bet on a point, lay odds behind the Don't Pass line does not charge commission (vig).====Come bet====A Come bet can be visualized as starting an entirely new Pass line bet, unique to that player.", "Like the Pass Line each player may only make one Come bet per roll, this does not exclude a player from betting odds on an already established Come point.", "This bet must be at least the table minimum and at most the table maximum.", "Players may bet both the Come and Don't Come on the same roll if desired.", "Come bets can only be made after a point has been established since, on the come-out roll, a Come bet would be the same thing as a Pass line bet.", "A player making a Come bet will bet on the first point number that \"comes\" from the shooter's next roll, regardless of the table's round.", "If a 7 or 11 is rolled on the first round, it wins.", "If a 2, 3, or 12 is rolled, it loses.", "If instead the roll is 4, 5, 6, 8, 9, or 10, the Come bet will be moved by the base dealer onto a box representing the number the shooter threw.", "This number becomes the \"come-bet point\" and the player is allowed to take odds, just like a Pass line bet.", "Also like a Pass line bet, the come bet is a contract bet and is always working, and cannot be turned \"Off\", removed or reduced until it wins or loses.", "However, the odds taken behind a Come bet can be turned \"Off\" (not working), removed or reduced anytime before the bet loses.", "In Las Vegas generally odds bets are required to be the table minimum.", "In Atlantic City and Pennsylvania, the combine odds and Pass bet must be table minimum so players can bet the minimum single unit depending on the point.", "If the point is a 4 or 10, players can bet as little as $1 if the table minimum is low such as $5, $10, or $15 minimums.", "If the player requests the Come odds to be not working (\"Off\") and the shooter sevens-out or hits the Come bet point, the Come bet will be lost or doubled and the Come odds returned.", "If the casino allows put betting a player may increase a Come bet after a point has been established and bet larger odds behind if desired.", "Put betting also allows a player to bet on a Come and take odds immediately on a point number without a Come bet point being established.The dealer will place the odds on top of the come bet, but slightly off center in order to differentiate between the original bet and the odds.", "The second round wins if the shooter rolls the come bet point again before a seven.", "Winning come bets are paid the same as winning Pass line bets: even money for the original bet and true odds for the odds bet.", "If, instead, the seven is rolled before the come-bet point, the come bet (and any odds bet) loses.Because of the come bet, if the shooter makes their point, a player can find themselves in the situation where they still have a come bet (possibly with odds on it) and the next roll is a come-out roll.", "In this situation, odds bets on the come wagers are usually presumed to be not working for the come-out roll.", "That means that if the shooter rolls a 7 on the come-out roll, any players with active come bets waiting for a come-bet point lose their initial wager but will have their odds bets returned to them.If the come-bet point is rolled on the come-out roll, the odds do not win but the come bet does and the odds bet is returned (along with the come bet and its payoff).", "The player can tell the dealer that they want their odds working, such that if the shooter rolls a number that matches the come point, the odds bet will win along with the come bet, and if a seven is rolled, both lose.Many players will use a come bet as \"insurance\" against sevening out: if the shooter rolls a seven, the come bet pays 1:1, offsetting the loss of the Pass line bet.", "The risk in this strategy is the situation where the shooter does not hit a seven for several rolls, leading to multiple come bets that will be lost if the shooter eventually sevens out.====Don't Come bet====In the same way that a come bet is similar to a Pass line bet, a Don't Come bet is similar to a Don't Pass bet.", "Like the come, the Don't Come can only be bet after a point has already been established as it is the same as a Don't Pass line bet when no point is established.", "This bet must be at least the table minimum and at most the table maximum.", "A Don't Come bet is played in two rounds.", "If a 2 or 3 is rolled in the first round, it wins.", "If a 7 or 11 is rolled, it loses.", "If a 12 is rolled, it is a push (subject to the same 2/12 switch described above for the Don't Pass bet).", "If, instead, the roll is 4, 5, 6, 8, 9, or 10, the Don't Come bet will be moved by the base dealer onto a box representing the number the shooter threw.", "The second round wins if the shooter rolls a seven before the Don't Come point.", "Like the Don't Pass each player may only make one Don't Come bet per roll, this does not exclude a player from laying odds on an already established Don't Come points.", "Players may bet both the Don't Come and Come on the same roll if desired.The player may lay odds on a Don't Come bet, just like a Don't Pass bet; in this case, the dealer (not the player) places the odds bet on top of the bet in the box, because of limited space, slightly offset to signify that it is an odds bet and not part of the original Don't Come bet.", "Lay odds behind a Don't Come are subject to the same rules as Don't Pass lay odds.", "Unlike a standard lay bet on a point, lay odds behind a Don't Come point does not charge commission (vig) and gives the player true odds.", "Like the Don't Pass line bet, Don't Come bets are no-contract, and can be removed or reduced after a Don't Come point has been established, but cannot be turned off (\"not working\") without being removed.", "A player may also call, \"No Action\" when a point is established, and the bet will not be moved to its point.", "This play is not to the player's advantage.", "If the bet is removed, the player can no longer lay odds behind the Don't Come point and cannot restore or increase the same Don't Come bet.", "Players must wait until next roll as long as a Pass line point has been established (players cannot bet Don't Come on come out rolls) before they can make a new Don't Come bet.", "Las Vegas casinos which allow put betting allows players to move the Don't Come directly to any Come point as a put; however, this is not allowed in Atlantic City or Pennsylvania.", "Unlike the Don't Come bet itself, the Don't Come odds can be turned \"Off\" (not working), removed, or reduced if desired.", "In Las Vegas, players generally must lay at least table minimum on odds if desired and win less than table minimum; in Atlantic City and Pennsylvania a player's combined bet must be at least table minimum, so depending on the point number players may lay as little as 2 minimum units (e.g.", "if the point is 4 or 10).", "If the player requests the Don't Come odds be not working (\"Off\") and the shooter hits the Don't Come point or sevens-out, the Don't Come bet will be lost or doubled and the Don't Come odds returned.Winning Don't Come bets are paid the same as winning Don't Pass bets: even money for the original bet and true odds for the odds lay.", "Unlike come bets, the odds laid behind points established by Don't Come bets are always working including come out rolls unless the player specifies otherwise.===Multi-roll bets===These are bets that may not be settled on the first roll and may need any number of subsequent rolls before an outcome is determined.Most multi-roll bets may fall into the situation where a point is made by the shooter before the outcome of the multi-roll bet is decided.", "These bets are often considered \"not working\" on the new come-out roll until the next point is established, unless the player calls the bet as \"working.", "\"Casino rules vary on this; some of these bets may not be callable, while others may be considered \"working\" during the come-out.", "Dealers will usually announce if bets are working unless otherwise called off.", "If a non-working point number placed, bought or laid becomes the new point as the result of a come-out, the bet is usually refunded, or can be moved to another number for free.====Place====Players can bet any point number (4, 5, 6, 8, 9, 10) by placing their wager in the come area and telling the dealer how much and on what number(s), \"30 on the 6\", \"5 on the 5\", or \"25 on the 10\".", "These are typically \"Place Bets to Win\".", "These are bets that the number bet on will be rolled before a 7 is rolled.", "These bets are considered working bets, and will continue to be paid out each time a shooter rolls the number bet.", "On a come-out roll, a place bet is considered to be not in effect unless the player who made it specifies otherwise.", "This bet may be removed or reduced at any time until it loses; in the latter case, the player must abide by any table minimums.Place bets to win pay out at slightly worse than the true odds: 9-to-5 on points 4 or 10, 7-to-5 on points 5 or 9, and 7-to-6 on points 6 or 8.The place bets on the outside numbers (4,5,9,10) should be made in units of $5, (on a $5 minimum table), in order to receive the correct exact payout of $5 paying $7 or $5 paying $9.The place bets on the 6 & 8 should be made in units of $6, (on a $5 minimum table), in order to receive the correct exact payout of $6 paying $7.For the 4 and 10, it is to the player's advantage to 'buy' the bet (see below).An alternative form, rarely offered by casinos, is the \"place bet to lose.\"", "This bet is the opposite of the place bet to win and pays off if a 7 is rolled before the specific point number.", "The place bet to lose typically carries a lower house edge than a place bet to win.", "Payouts are 4–5 on points 6 or 8, 5–8 on 5 or 9, and 5–11 on 4 or 10.====Buy====Players can also buy a bet which are paid at true odds, but a 5% commission is charged on the amount of the bet.", "Buy bets are placed with the shooter betting at a specific number will come out before a player sevens out.", "The buy bet must be at least table minimum excluding commission; however, some casinos require the minimum buy bet amount to be at least $20 to match the $1 charged on the 5% commission.", "Traditionally, the buy bet commission is paid no matter what, but in recent years a number of casinos have changed their policy to charge the commission only when the buy bet wins.", "Some casinos charge the commission as a one-time fee to buy the number; payouts are then always at true odds.", "Most casinos usually charge only $1 for a $25 green-chip bet (4% commission), or $2 for $50 (two green chips), reducing the house advantage a bit more.", "Players may remove or reduce this bet (bet must be at least table minimum excluding vig) anytime before it loses.", "Buy bets like place bets are not working when no point has been established unless the player specifies otherwise.Where commission is charged only on wins, the commission is often deducted from the winning payoff—a winning $25 buy bet on the 10 would pay $49, for instance.", "The house edges stated in the table assume the commission is charged on all bets.", "They are reduced by at least a factor of two if commission is charged on winning bets only.====Lay====A lay bet is the opposite of a buy bet, where a player bets on a 7 to roll before the number that is laid.", "Players may only lay the 4, 5, 6, 8, 9, or 10 and may lay multiple numbers if desired.", "Just like the buy bet lay bets pay true odds, but because the lay bet is the opposite of the buy bet, the payout is reversed.", "Therefore, players get 1 to 2 for the numbers 4 and 10, 2 to 3 for the numbers 5 and 9, and 5 to 6 for the numbers 6 and 8.A 5% commission (vigorish, vig, juice) is charged up front on the possible winning amount.", "For example: A $40 Lay Bet on the 4 would pay $20 on a win.", "The 5% vig would be $1 based on the $20 win.", "(not $2 based on the $40 bet as the way buy bet commissions are figured.)", "Like the buy bet the commission is adjusted to suit the betting unit such that fraction of a dollar payouts are not needed.", "Casinos may charge the vig up front thereby requiring the player to pay a vig win or lose, other casinos may only take the vig if the bet wins.", "Taking vig only on wins lowers house edge.", "Players may removed or reduce this bet (bet must be at least table minimum) anytime before it loses.", "Some casinos in Las Vegas allow players to lay table minimum plus vig if desired and win less than table minimum.", "Lay bet maximums are equal to the table maximum win, so if a player wishes to lay the 4 or 10, he or she may bet twice at amount of the table maximum for the win to be table maximum.", "Other casinos require the minimum bet to win at $20 even at the lowest minimum tables in order to match the $1 vig, this requires a $40 bet.", "Similar to buy betting, some casinos only take commission on win reducing house edge.", "Unlike place and buy bets, lay bets are always working even when no point has been established.", "The player must specify otherwise if he or she wishes to have the bet not working.If a player is unsure of whether a bet is a single or multi-roll bet, it can be noted that all single-roll bets will be displayed on the playing surface in one color (usually red), while all multi-roll bets will be displayed in a different color (usually yellow).====Put====A put bet is a bet which allows players to increase or make a Pass line bet after a point has been established (after come-out roll).", "Players may make a put bet on the Pass line and take odds immediately or increase odds behind if a player decides to add money to an already existing Pass line bet.", "Put betting also allows players to increase an existing come bet for additional odds after a come point has been established or make a new come bet and take odds immediately behind if desired without a come bet point being established.", "If increased or added put bets on the Pass line and Come cannot be turned \"Off\", removed or reduced, but odds bet behind can be turned \"Off\", removed or reduced.", "The odds bet is generally required to be the table minimum.", "Player cannot put bet the Don't Pass or Don't Come.", "Put betting may give a larger house edge over place betting unless the casino offers high odds.Put bets are generally allowed in Las Vegas, but not allowed in Atlantic City and Pennsylvania.Put bets are better than place bets (to win) when betting more than 5-times odds over the flat bet portion of the put bet.", "For example, a player wants a $30 bet on the six.", "Looking at two possible bets: 1) Place the six, or 2) Put the six with odds.", "A $30 place bet on the six pays $35 if it wins.", "A $30 put bet would be a $5 flat line bet plus $25 (5-times) in odds, and also would pay $35 if it wins.", "Now, with a $60 bet on the six, the place bet wins $70, where the put bet ($5 + $55 in odds) would pay $71.The player needs to be at a table which not only allows put bets, but also high-times odds, to take this advantage.====Hard way====This bet can only be placed on the numbers 4, 6, 8, and 10.In order for this bet to win, the chosen number must be rolled the \"hard way\" (as doubles) before a 7 or any other non-double combination (\"easy way\") totaling that number is rolled.", "For example, a player who bets a hard 6 can only win by seeing a 3–3 roll come up before any 7 or any easy roll totaling 6 (4–2 or 5–1); otherwise, the player loses.In Las Vegas casinos, this bet is generally working, including when no point has been established, unless the player specifies otherwise.", "In other casinos such as those in Atlantic City, hard ways are not working when the point is off unless the player requests to have it working on the come out roll.Like single-roll bets, hard way bets can be lower than the table minimum; however, the maximum bet allowed is also lower than the table maximum.", "The minimum hard way bet can be a minimum one unit.", "For example, lower stake table minimums of $5 or $10, generally allow minimum hard ways bets of $1.The maximum bet is based on the maximum allowed win from a single roll.Easy way is not a specific bet offered in standard casinos, but a term used to define any number combination which has two ways to roll.", "For example, (6–4, 4–6) would be a \"10 easy\".", "The 4, 6, 8 or 10 can be made both hard and easy ways.", "Betting point numbers (which pays off on easy or hard rolls of that number) or single-roll (\"hop\") bets (e.g., \"hop the 2–4\" is a bet for the next roll to be an easy six rolled as a two and four) are methods of betting easy ways.====Big 6 and Big 8====A player can choose either the 6 or 8 being rolled before the shooter throws a seven.", "These wagers are usually avoided by experienced craps players since they pay even money (1:1) while a player can make place bets on the 6 or the 8, which pay more (7:6).", "Some casinos (especially all those in Atlantic City) do not even offer the Big 6 & 8.The bets are located in the corners behind the Pass line, and bets may be placed directly by players.The only real advantage offered by the Big 6 & 8 is that they can be bet for the table minimum, whereas a place bet minimum may sometimes be greater than the table minimum (e.g.", "$6 place bet on a $3 minimum game.)", "In addition place bets are usually not working, except by agreement, when the shooter is \"coming out\" i.e.", "shooting for a point, and Big 6 and 8 bets always work.", "Some modern layouts no longer show the Big 6/Big 8 bet.===Single-roll bets===Single-roll (proposition) bets are resolved in one dice roll by the shooter.", "Most of these are called \"service bets\", and they are located at the center of most craps tables.", "Only the stickman or a dealer can place a service bet.", "Single-roll bets can be lower than the table minimum, but the maximum bet allowed is also lower than the table maximum.", "The maximum bet is based on the maximum allowed win from a single roll.", "The lowest single-roll bet can be a minimum one unit bet.", "For example, tables with minimums of $5 or $10 generally allow minimum single-roll bets of $1.Single bets are always working by default unless the player specifies otherwise.", "The bets include:;2 (snake eyes, or Aces): Wins if shooter rolls a 2.;3 (ace-deuce): Wins if the shooter rolls a 3.;Yo: Wins if the shooter rolls 11.;12 (boxcars, midnight, or cornrows): Wins if shooter rolls a 12.;2 or 12 (hi-lo): Wins if shooter rolls a 2 or 12.The stickman places this bet on the line dividing the 2 and 12 bets.", ";Any Craps (Three-Way): Wins if the shooter rolls 2, 3 or 12.;C & E: A combined bet, a player is betting half their bet on craps (2,3,12) and the other half on 11 (yo).", "The combine payout is 3:1 on craps and 7:1 on 11 (yo).", "Another method of calculating the payout is to divide the total bet in half.", "The player would receive 7:1 minus half the total bet payout on half the total bet for craps and 15:1 minus half the total bet payout on half the total bet for 11 (yo).", "For example, using this method if a player were to bet $2 on C & E, $1 would receive 7:1 payout on craps minus $1 for the bet on 11 so the total profit would be $6.If an 11 was rolled the player would receive 15:1 minus $1 for the bet on craps so the player's total profit is $14.Both methods of calculation yield the same result so either method can be used.", "If a player wishes to take the bet down after a win the player would receive the whole bet not half even though only one of the two bets can win per roll.", "The minimum bet on C & E is double the lowest unit bet allowed at the table.", "So if the minimum single roll bet is $1 the lowest C & E bet allowed would be $2.Players are, however, able to make odd number bets larger than $2 if desired.", "One of the two bets will always lose, the other may win.", ";Any seven: A single roll bet which wins if the shooter rolls a 7 with 4:1 payout.", "This bet is also nicknamed Big Red, since the 7 on its betting space on the layout is usually large and red, and it is considered bad luck and a breach of etiquette among gamblers to speak the word \"seven\" at the table.", ";Horn: This is a bet that involves betting on 1 unit each for 2, 3, 11, and 12 at the same time for the next roll.", "The bet is actually four separate bets, and pays off depending on which number is actually rolled.", "The combined payout is 27:4 for 2, 12 and 3:1 for 3, 11.Each individual bet has the same payout as a single bet on the specific numbers, 30:1 for 2 and 12 minus the other three bets, 15:1 for 3 and 11 minus the other three bets.", "If a player wins the bet he can take down all four bets instead of a single bet even though only one bet can win per roll.", "Many players, in order to eliminate the confusion of tossing four chips to the center of the table or having change made while bets are being placed, will make a five-unit Horn High bet, which is a four-way bet with the extra unit going to one specific number.", "For example, if one tosses a $5 chip into the center and says \"horn high yo\", they are placing four $1 bets on each of the horn numbers and the extra dollar will go on the yo (11).", "Horn bets are generally required to be in multiples of 4 or 5 with the minimum bet being 4 times the minimum unit allowed.", "For example, if the single roll minimum at the table is $1 the Horn bet must be $4 or more.", ";Whirl or World: A five-unit bet that is a combination of a horn and any-seven bet, with the idea that if a seven is rolled the bet is a push, because the money won on the seven is lost on the horn portions of the bet.", "The combine odds are 26:5 on the 2, 12, 11:5 on the 3, 11, and a push on the 7.Like the C & E and Horn bet, if a player wishes to take down the bet after a win he or she would receive all five units back.", "The minimum bet is five of the minimum units.", "For example, if the minimum single roll bet is $1, the minimum World/Whirl bet is $5.", ";On the Hop: (also Hop, or Hopping) A single roll bet on any particular combination of the two dice on the next roll including combinations whose sum is 7 (e.g.", "4 and 3).", "For example, if someone bets on \"5 and 1\" on the hop, they are betting that the next roll will have a 5 on one die and a 1 on the other die.", "The bet pays 15:1 on easy ways (same as a bet on 3 or 11).", "Hard ways hop pays 30:1 (e.g., 3 and 3 on the hop, same as a bet on 2 or 12).", "The true odds are 17:1 and 35:1, resulting in a house edge of 11.11% and 13.89% respectively.", "When presented, hop bets are located at the center of the craps layout with the other proposition bets.", "If hop bets are not on the craps layout, they still may be bet on by players but they become the responsibility of the boxman to book the bet.", "Sometimes players may request to hop a whole number.", "In this case the money on the bet different combinations.", "For example, if a player says \"hop the tens\" (6–4, 5–5, 4–6) the player must give the dealer an even number bet so it can be divided among the hard and easy ways.", "If the player gives $10, $5 would be placed on the easy ways 10 with 15:1 odds and $5 would be placed on the hard way with 30:1 odds.", "If a player wishes to \"hop the sevens\" there would be three different combinations and six possible ways to roll a 7 (6–1, 5–2, 4–3, 3–4, 2–5, 1–6) therefore the player should bet in multiples of 3 so the bet can be divided among each combination with a 15:1 payout minus the other two bets, otherwise if players does not bet in multiples of 3, they would specific which combination has additional units.", ";Field: This bet is a wager that one of the numbers 2, 3, 4, 9, 10, 11, or 12 will appear on the next roll of the dice.", "This bet typically pays more (2:1 or 3:1) if 2 or 12 is rolled, and 1:1 if 3, 4, 9, 10, or 11 is rolled.", "The Field bet is a \"Self-Service\" Bet.", "Unlike the other proposition bets which are handled by the dealers or stickman, the field bet is placed directly by the player.", "Players identify their Field bets by placing them in the Field area directly in front of them or as close to their position as possible.", "The initial bet and/or any payouts can \"ride\" through several rolls until they lose, and are assumed to be \"riding\" by dealers.", "It is thus the player's responsibility to collect their bet and/or winnings immediately upon payout, before the next dice roll, if they do not wish to let it ride.===Player bets===Fire Bet: Before the shooter begins, some casinos will allow a bet known as a fire bet to be placed.", "A fire bet is a bet of as little as $1 and generally up to a maximum of $5 to $10 sometimes higher, depending on casino, made in the hope that the next shooter will have a hot streak of setting and getting many points of different values.", "As different individual points are made by the shooter, they will be marked on the craps layout with a fire symbol.The first three points will not pay out on the fire bet, but the fourth, fifth, and sixth will pay out at increasing odds.", "The fourth point pays at 24-to-1, the fifth point pays at 249-to-1, and the 6th point pays at 999-to-1.", "(The points must all be different numbers for them to count toward the fire bet.)", "For example, a shooter who successfully hits a point of 10 twice will only garner credit for the first one on the fire bet.", "Players must hit the established point in order for it to count toward the fire bet.", "The payout is determine by the number of points which have been established and hit after the shooter sevens out.Bonus Craps: Prior to the initial \"come out roll\", players may place an optional wager (usually a $1 minimum to a maximum $25) on one or more of the three Bonus Craps wagers, \"All Small\", \"All Tall\", or \"All or Nothing at All.\"", "For players to win the \"All Small\" wager, the shooter must hit all five small numbers (2, 3, 4, 5, 6) before a seven is rolled; similarly, \"All Tall\" wins if all five high numbers (8, 9, 10, 11, 12) are hit before a seven is rolled.These bets pay 35-for-1, for a house advantage of 7.76%.", "\"All or Nothing at All\" wins if the shooter hits all 10 numbers before a seven is rolled.", "This pays 176-for-1, for a house edge of 7.46%.", "For all three wagers, the order in which the numbers are hit does not matter.", "Whenever a seven is hit, including on the come out roll, all bonus bets lose, the bonus board is reset, and new bonus bets may be placed.===Multiple different bets===A player may wish to make multiple different bets.", "For example, a player may be wish to bet $1 on all hard ways and the horn.", "If one of the bets win the dealer may automatically replenish the losing bet with profits from the winning bet.", "In this example, if the shooter rolls a hard 8 (pays 9:1), the horn loses.", "The dealer may return $5 to the player and place the other $4 on the horn bet which lost.", "If the player does not want the bet replenished, he or she should request any or all bets be taken down.===Working and not working bets===A working bet is a live bet.", "Bets may also be on the board, but not in play and therefore not working.", "Pass line and come bets are always working meaning the chips are in play and the player is therefore wagering live money.", "Other bets may be working or not working depending whether a point has been established or player's choice.", "Place and buy bets are working by default when a point is established and not working when the point is off unless the player specifies otherwise.", "Lay bets are always working even if a point has not been established unless the player requests otherwise.", "At any time, a player may wish to take any bet or bets out of play.", "The dealer will put an \"Off\" button on the player's specific bet or bets; this allows the player to keep his chips on the board without a live wager.", "For example, if a player decides not to wager a place bet mid-roll but wishes to keep the chips on the number, he or she may request the bet be \"not working\" or \"Off\".", "The chips remain on the table, but the player cannot win from or lose chips which are not working.The opposite is also allowed.", "By default place and buy bets are not working without an established point; a player may wish to wager chips before a point has been established.", "In this case, the player would request the bet be working in which the dealer will place an \"On\" button on the specified chips." ], [ "Bet odds and summary", ":Note: Individual casinos may pay some of these bets at different payout ratios than those listed below.", "Some bets are listed more than once below – the most common payout in North American casinos is listed first, followed by other known variants.", ":Note: \"True Odds\" do not vary.+ Bet SummaryBetTrue OddsOdds PaidHouse EdgeSingle or Multi RollWinLoseNotesPass / Come251:2441:11.41%MultiCome out roll: 7, 11.Once the point is established: the point number (one of: 4, 5, 6, 8, 9, 10)Come out roll: 2, 3, 12.Once the point is established: 7Considered a \"contract bet\": once the point is established, the bet is locked until it wins or loses.", "See Optimal betting.Don't Pass / Don't Come (Bar-12 or Bar-2)976:9491:11.36%MultiCome out roll: 2, 3Tie: 12 (depending on Bar)Once the point is established: 7Come out roll: 7, 11.Once the point is established: the point number (one of: 4, 5, 6, 8, 9, 10)Controlled by the player: can be decreased at any time, but see Optimal betting.Pass Odds / Come OddsSame as paid2:1 on 4,10;3:2 on 5,9;6:5 on 6,80%MultiOnce the point is established: the point number (one of: 4, 5, 6, 8, 9, 10)Once the point is established: 7Controlled by the player: can be increased or decreased at any timeDon't Pass Odds / Don't Come OddsSame as paid1:2 against 4,10;2:3 against 5,9;5:6 against 6,80%MultiOnce the point is established: 7Once the point is established: the point number (one of: 4, 5, 6, 8, 9, 10)Controlled by the player: can be increased or decreased at any timeYo (11)17:115:111.11%Single11Any other number317:115:111.11%Single3Any other number235:130:113.89%Single2Any other number1235:130:113.89%Single12Any other numberHi-Lo (2 or 12)17:115:111.11%Single2 or 12Any other numberCraps (2, 3, or 12)8:17:111.11%Single2, 3, 12Any other numberC & E (the combined bet)5:13:1 on 2,3,12;7:1 on 1111.11%Single2, 3, 11, 12Any other numberAny 75:14:116.67%Single7Any other numberField5:41:1 on 3,4,9,10,11;2:1 on 2,125.56% (2.78% if 12 pays 3:1)Single2,3,4,9,10,11,12Any other numberMost common payout scheduleSome casinos pays 2:1 for 2 and 3:1 for 12, reducing house edge to 2.78%Horn (the combined bet)5:127:4 on 2,12;3:1 on 3,1112.5%Single2,3,11,12Any other numberWhirl/World (the combined bet)2:126:5 on 2,12;11:5 on 3,11;0:1 (push) on 713.33%Single2,3,7,11,12Any other numberHard 4 / Hard 108:17:111.11%Multi4/10 as a pair (2-2/5-5)7, 4/10 as a non-pair (1-3/4-6)In the UK and Australia, the payout is 7.5:1 lowering the house edge to 5.56%.Hard 6 / Hard 810:19:19.09%Multi6/8 as a pair (3-3/4-4)7, 6/8 as a non-pair (1–5,2-4/2-6,3-5)In the UK and Australia, the payout is 9.5:1 lowering the house edge to 4.55%.Big 6 / Big 86:51:19.09%Multi6/87Place 4 / Place 102:19:56.67%Multi4/107Same true odds, better payout if the player buys the 4/10Place 5 / Place 93:27:54%Multi5/97Place 6 / Place 86:57:61.52%Multi6/87Buy 4 / Buy 102:12:1 -5% of intended bet4.76% (1.67% if commission taken only on win)Multi4/107Certain casinos such as Santa Ana Star Casino offer \"Free buy\" reducing house edge to 0%Buy 5 / Buy 93:23:2 -5% of intended bet4.76% (1.96% if commission taken only on win)Multi5/97Same true odds, better payout if the player places the 5/9Buy 6 / Buy 86:56:5 -5% of intended bet4.76% (2.22% if commission taken only on win)Multi6/87Same true odds, better payout if the player places the 6/8Lay 4 / Lay 101:21:2 -5% of intended win2.44% (1.67% if commission taken only on win)Multi74/10Lay 5 / Lay 92:32:3 -5% of intended win3.23% (2% if commission taken only on win)Multi75/9Lay 6 / Lay 85:65:6 -5% intended win4.00% (2.27% if commission taken only on win)Multi76/8The probability of dice combinations determine the odds of the payout.", "The following chart shows the dice combinations needed to roll each number.", "The two and twelve are the hardest to roll since only one combination of dice is possible.", "The game of craps is built around the dice roll of seven, since it is the most easily rolled dice combination.Dice RollPossible Dice Combinations21–131–2, 2–141–3, 2–2, 3–151–4, 2–3, 3–2, 4–161–5, 2–4, 3–3, 4–2, 5–171–6, 2–5, 3–4, 4–3, 5–2, 6–182–6, 3–5, 4–4, 5–3, 6–293–6, 4–5, 5–4, 6–3104–6, 5–5, 6–4115–6, 6–5126–6Viewed another way: + Die ADie B123456123456723456783456789456789105678910116789101112The expected value of all bets is usually negative, such that the average player will always lose money.", "This is because the house always sets the paid odds to below the actual odds.", "The only exception is the \"odds\" bet that the player is allowed to make after a point is established on a pass/come Don't Pass/Don't Come bet (the odds portion of the bet has a long-term expected value of 0).", "However, this \"free odds\" bet cannot be made independently, so the expected value of the entire bet, including odds, is still negative.", "Since there is no correlation between die rolls, there is normally no possible long-term winning strategy in craps.There are occasional promotional variants that provide either no house edge or even a player edge.", "One example is a field bet that pays 3:1 on 12 and 2:1 on either 3 or 11.Overall, given the 5:4 true odds of this bet, and the weighted average paid odds of approximately 7:5, the player has a 5% advantage on this bet.", "This is sometimes seen at casinos running limited-time incentives, in jurisdictions or gaming houses that require the game to be fair, or in layouts for use in informal settings using play money.", "No casino currently runs a craps table with a bet that yields a player edge full-time.Maximizing the size of the odds bet in relation to the line bet will reduce, but never eliminate the house edge, and will increase variance.", "Most casinos have a limit on how large the odds bet can be in relation to the line bet, with single, double, and five times odds common.", "Some casinos offer 3–4–5 odds, referring to the maximum multiple of the line bet a player can place in odds for the points of 4 and 10, 5 and 9, and 6 and 8, respectively.", "During promotional periods, a casino may even offer 100x odds bets, which reduces the house edge to almost nothing, but dramatically increases variance, as the player will be betting in large betting units.Since several of the multiple roll bets pay off in ratios of fractions on the dollar, it is important that the player bets in multiples that will allow a correct payoff in complete dollars.", "Normally, payoffs will be rounded down to the nearest dollar, resulting in a higher house advantage.", "These bets include all place bets, taking odds, and buying on numbers 6, 8, 5, and 9, as well as laying all numbers." ], [ "Betting variants", "These variants depend on the casino and the table, and sometimes a casino will have different tables that use or omit these variants and others.", "* 11 is a point number instead of a natural.", "Rolling an 11 still pays \"Yo\" center-table bets, but the Pass line does not automatically win (and the Don't Pass line doesn't automatically lose) when 11 is rolled on the come-out.", "Making the point pays 3:1 on Pass/Come odds bets (1:3 on Don't Pass/Come odds); all line bets are still even money.", "This substantially reduces the odds of a natural (from 8/36 to 6/36) and of making the point in general (since a 3:1 dog is added to the mix).", "All other things equal, the house edge on the Pass Line and Come bets for this play variation jumps dramatically to 9.75%.", "* 12 pays 3:1 on the field.", "This is generally seen in rooms that have two different table minimums, on the tables with the higher minimums.", "The lower minimum ones will then have 2:1 odds.", "For example, the Mirage casino in Las Vegas features 3:1 odds.", "* 11 pays 2:1 on the field.", "This variant is normally used when 12 pays 3:1, and neutralizes the house edge on the field.", "* Big 6/8 are unavailable.", "These bets are equivalent to placing or buying 6 or 8 as points, which have better payout for the same real odds, so Big 6/8 are rarely used and many casinos simply omit them from the layout.", "Casinos in Atlantic City are even prohibited by law from offering Big 6/8 bets." ], [ "Optimal betting", "When craps is played in a casino, all bets have a house advantage.", "That is, it can be shown mathematically that a player will (with 100% probability) lose all his or her money to the casino in the long run, while in the short run the player is more likely to lose money than make money.", "There may be players who are lucky and get ahead for a period of time, but in the long run these winning streaks are eroded away.", "One can slow, but not eliminate, one's average losses by only placing bets with the smallest house advantage.The Pass/Don't Pass line, Come/Don't Come line, place 6, place 8, buy 4 and buy 10 (only under the casino rules where commission is charged only on wins) have the lowest house edge in the casino, and all other bets will, on average, lose money between three and twelve times faster because of the difference in house edges.The place bets and buy bets differ from the Pass line and come line, in that place bets and buy bets can be removed at any time, since, while they are multi-roll bets, their odds of winning do not change from roll to roll, whereas Pass line bets and come line bets are a combination of different odds on their first roll and subsequent rolls.", "The first roll of a Pass line bet is 2:1 advantage for the player (8 wins, 4 losses), but it's \"paid for\" by subsequent rolls that are at the same disadvantage to the player as the Don't Pass bets were at an advantage.", "As such, they cannot profitably let the player take down the bet after the first roll.", "Players can bet or lay odds behind an established point depending on whether it was a Pass/Come or Don't Pass/Don't Come to lower house edge by receiving true odds on the point.", "Casinos which allow put betting allows players to increase or make new pass/come bets after the come-out roll.", "This bet generally has a higher house edge than place betting, unless the casino offers high odds.Conversely, a player can take back (pick up) a Don't Pass or Don't Come bet after the first roll, but this cannot be recommended, because they already endured the disadvantaged part of the combination – the first roll.", "On that come-out roll, they win just 3 times (2 and 3), while losing 8 of them (7 and 11) and pushing one (12) out of the 36 possible rolls.", "On the other 24 rolls that become a point, their Don't Pass bet is now to their advantage by 6:3 (4 and 10), 6:4 (5 and 9) and 6:5 (6 and 8).", "If a player chooses to remove the initial Don't Come and/or Don't Pass line bet, he or she can no longer lay odds behind the bet and cannot re-bet the same Don't Pass and/or Don't Come number (players must make a new Don't Pass or come bets if desired).", "However, players can still make standard lay bets odds on any of the point numbers (4,5,6,8,9,10).Among these, and the remaining numbers and possible bets, there are a myriad of systems and progressions that can be used with many combinations of numbers.An important alternative metric is house advantage per roll (rather than per bet), which may be expressed in loss per hour.", "The typical pace of rolls varies depending on the number of players, but 102 rolls per hour is a cited rate for a nearly full table.", "This same reference states that only \"29.6% of total rolls are come out rolls, on average\", so for this alternative metric, needing extra rolls to resolve the Pass line bet, for example, is factored.", "This number then permits calculation of rate of loss per hour, and per the 4 day/5 hour per day gambling trip:* $10 Pass line bets 0.42% per roll, $4.28 per hour, $86 per trip* $10 Place 6,8 bets 0.46% per roll, $4.69 per hour, $94 per trip* $10 Place 5,9 bets 1.11% per roll, $11.32 per hour, $226 per trip* $10 Place 4,10 bets 1.19% per roll, $12.14 per hour, $243 per trip* $1 Single Hardways 2.78% per roll, $2.84 per hour, $56.71 per trip* $1 All hardways 2.78% per roll, $11.34 per hour, $227 per trip* $5 All hardways 2.78% per roll, $56.71 per hour, $1134 per trip* $1 Craps only on come out 3.29% per roll, $3.35 per hour, $67.09 per trip* $1 Eleven only on come out 3.29% per roll, $3.35 per hour, $67.09 per trip" ], [ "Table rules", "Besides the rules of the game itself, a number of formal and informal rules are commonly applied in the table form of Craps, especially when played in a casino.To reduce the potential opportunity for switching dice by sleight-of-hand, players are not supposed to handle the dice with more than one hand (such as shaking them in cupped hands before rolling) nor take the dice past the edge of the table.", "If a player wishes to change shooting hands, they may set the dice on the table, let go, then take them with the other hand.When throwing the dice, the player is expected to hit the farthest wall at the opposite end of the table (these walls are typically augmented with pyramidal structures to ensure highly unpredictable bouncing after impact).", "Casinos will sometimes allow a roll that does not hit the opposite wall as long as the dice are thrown past the middle of the table; a very short roll will be nullified as a \"no roll\".", "The dice may not be slid across the table and must be tossed.", "These rules are intended to prevent dexterous players from physically influencing the outcome of the roll.Players are generally asked not to throw the dice above a certain height (such as the eye level of the dealers).", "This is both for the safety of those around the table, and to eliminate the potential use of such a throw as a distraction device in order to cheat.Dice are still considered \"in play\" if they land on players' bets on the table, the dealer's working stacks, on the marker puck, or with one die resting on top of the other.", "The roll is invalid if either or both dice land in the boxman's bank, the stickman's bowl (where the extra three dice are kept between rolls), or in the rails around the top of the table where players chips are kept.", "If one or both dice hits a player or dealer and rolls back onto the table, the roll counts as long as the person being hit did not intentionally interfere with either of the dice, though some casinos will rule \"no roll\" for this situation.", "If one or both leave the table, it is also a \"no roll\", and the dice may either be replaced or examined by the boxman and returned to play.Shooters may wish to \"set\" the dice to a particular starting configuration before throwing (such as showing a particular number or combination, stacking the dice, or spacing them to be picked up between different fingers), but if they do, they are often asked to be quick about it so as not to delay the game.", "Some casinos disallow such rituals to speed up the pace of the game.", "Some may also discourage or disallow unsanitary practices such as kissing or spitting on the dice.In most casinos, players are not allowed to hand anything directly to dealers, and vice versa.", "Items such as cash, checks, and chips are exchanged by laying them down on the table; for example, when \"buying in\" (paying cash for chips), players are expected to place the cash on the layout: the dealer will take it and then place the chips in front of the player.", "This rule is enforced in order to allow the casino to easily monitor and record all transfers via overhead surveillance cameras, and to reduce the opportunity for cheating via sleight-of-hand.Most casinos prohibit \"call bets\", and may have a warning such as \"No Call Bets\" printed on the layout to make this clear.", "This means a player may not call out a bet without also placing the corresponding chips on the table.", "Such a rule reduces the potential for misunderstanding in loud environments, as well as disputes over the amount that the player intended to bet after the outcome has been decided.", "Some casinos choose to allow call bets once players have bought-in.", "When allowed, they are usually made when a player wishes to bet at the last second, immediately before the dice are thrown, to avoid the risk of obstructing the roll." ], [ "Etiquette", "Craps is among the most social and most superstitious of all gambling games, which leads to an enormous variety of informal rules of etiquette that players may be expected to follow.", "An exhaustive list of these is beyond the scope of this article, but the guidelines below are most commonly given.=== Tips ===Tipping the dealers is universal and expected in Craps.", "As in most other casino games, a player may simply place (or toss) chips onto the table and say, \"For the dealers\", \"For the crew\", ''etc.''", "In craps, it is also common to place a bet for the dealers.", "This is usually done one of three ways: by placing an ordinary bet and simply declaring it for the dealers, as a \"two-way\", or \"on top\".", "A \"Two-Way\" is a bet for both parties: for example, a player may toss in two chips and say \"Two Way Hard Eight\", which will be understood to mean one chip for the player and one chip for the dealers.", "Players may also place a stack of chips for a bet as usual, but leave the top chip off-center and announce \"on top for the dealers\".", "The dealer's portion is often called a \"toke\" bet, which comes from the practice of using $1 slot machine tokens to place dealer bets in some casinos.In some cases, players may also tip each other, for example as a show of gratitude to the thrower for a roll on which they win a substantial bet.=== Superstition ===Craps players routinely practice a wide range of superstitious behaviors, and may expect or demand these from other players as well.Most prominently, it is universally considered bad luck to say the word \"seven\" (after the \"come-out\", a roll of 7 is a loss for \"pass\" bets).", "Dealers themselves often make significant efforts to avoid calling out the number.", "When necessary, participants may refer to seven with a \"nickname\" such as \"Big Red\" (or just \"Red\"), \"the S-word\", etc." ], [ "Systems", "=== Martingale system ===Although no wagering system can consistently beat casino games based on independent trials such as craps, that does not stop gamblers from believing in them.", "One of the best known systems is the Martingale System.", "In this strategy, the gambler doubles his bet after every loss.", "After a win, the bet is reset to the original bet.", "The theory is that the first win would recover all previous losses plus win a profit equal to the original stake.=== Gambler's fallacy ===Other systems depend on the gambler's fallacy, which in craps terms is the belief that past dice rolls influence the probabilities of future dice rolls.", "For example, the gambler's fallacy indicates that a craps player should bet on eleven if an eleven has not appeared or has appeared too often in the last 20 rolls.", "In practice this can be observed as players respond to a roll such as a Hard Six with an immediate wager on the Hard Six.In reality, each roll of the dice is an independent event, so the probability of rolling eleven is exactly 1/18 on every roll, regardless of the number of times eleven has come up in the last x rolls.", "Even if the dice are actually biased toward particular results (\"loaded\"), each roll is still independent of all the previous ones.", "The common term to describe this is \"dice have no memory\".===Dice setting or dice control===Another approach is to \"set\" the dice in a particular orientation, and then throw them in such a manner that they do not tumble randomly.", "The theory is that given exactly the same throw from exactly the same starting configuration, the dice will tumble in the same way and therefore show the same or similar values every time.Casinos take steps to prevent this.", "The dice are usually required to hit the back wall of the table, which is normally faced with a jagged angular texture such as pyramids, making controlled spins more difficult.", "There has been no independent evidence that such methods can be successfully applied in a real casino." ], [ "Variants", "Bank craps is a variation of the original craps game and is sometimes known as Las Vegas Craps.", "This variant is quite popular in Nevada gambling houses, and its availability online has now made it a globally played game.", "Bank craps uses a special table layout and all bets must be made against the house.", "In Bank Craps, the dice are thrown over a wire or a string that is normally stretched a few inches from the table's surface.", "The lowest house edge (for the Pass/Don't Pass) in this variation is around 1.4%.", "Generally, if the word \"craps\" is used without any modifier, it can be inferred to mean this version of the game, to which most of this article refers.Crapless craps, also known as bastard craps, is a simple version of the original craps game, and is normally played as an online private game.", "The biggest difference between crapless craps and original craps is that the shooter (person throwing the dice) is at a far greater disadvantage and has a house edge of 5.38%.", "Another difference is that this is one of the craps games in which a player can bet on rolling a 2, 3, 11 or 12 before a 7 is thrown.", "In crapless craps, 2 and 12 have odds of 11:2 and have a house edge of 7.143% while 3 and 11 have odds of 11:4 with a house edge of 6.25%.New York Craps is one of the variations of craps played mostly in the Eastern coast of the US, true to its name.", "History states that this game was actually found and played in casinos in Yugoslavia, the UK and the Bahamas.", "In this craps variant, the house edge is greater than Las Vegas Craps or Bank craps.", "The table layout is also different, and is called a double-end-dealer table.", "This variation is different from the original craps game in several ways, but the primary difference is that New York craps doesn't allow Come or Don't Come bets.", "New York Craps Players bet on box numbers like 4, 5, 6, 8, 9, or 10.The overall house edge in New York craps is 5%." ], [ "Card-based variations", "In order to get around Californian laws barring the payout of a game being directly related to the roll of dice, Indian reservations have adapted the game to substitute cards for dice.===Cards replacing dice===To replicate the original dice odds exactly without dice or possibility of card-counting, one scheme uses two shuffle machines each with just one deck of Ace through 6 each.", "Each machine selects one of the 6 cards at random and this is the roll.", "The selected cards are replaced and the decks are reshuffled for the next roll.In one variation, two shoes are used, each containing some number of regular card decks that have been stripped down to just the Aces and deuces through sixes.", "The boxman simply deals one card from each shoe and that is the roll on which bets are settled.", "Since a card-counting scheme is easily devised to make use of the information of cards that have already been dealt, a relatively small portion (less than 50%) of each shoe is usually dealt in order to protect the house.In a similar variation, cards representing dice are dealt directly from a continuous shuffling machine (CSM).", "Typically, the CSM will hold approximately 264 cards, or 44 sets of 1 through 6 spot cards.", "Two cards are dealt from the CSM for each roll.", "The game is played exactly as regular craps, but the roll distribution of the remaining cards in the CSM is slightly skewed from the normal symmetric distribution of dice.Even if the dealer were to shuffle each roll back into the CSM, the effect of buffering a number of cards in the chute of the CSM provides information about the skew of the next roll.", "Analysis shows this type of game is biased towards the Don't Pass and Don't Come bets.", "A player betting Don't Pass and Don't Come every roll and laying 10x odds receives a 2% profit on the initial Don't Pass / Don't Come bet each roll.", "Using a counting system allows the player to attain a similar return at lower variance.===Cards mapping physical dice===In this game variation, one red deck and one blue deck of six cards each (A through 6), and a red die and a blue die are used.", "Each deck is shuffled separately, usually by machine.", "Each card is then dealt onto the layout, into the 6 red and 6 blue numbered boxes.", "The shooter then shoots the dice.", "The red card in the red-numbered box corresponding to the red die, and the blue card in the blue-numbered box corresponding to the blue die are then turned over to form the roll on which bets are settled.Another variation uses a red and a blue deck of 36 custom playing cards each.", "Each card has a picture of a two-die roll on it – from 1–1 to 6–6.The shooter shoots what looks like a red and a blue die, called \"cubes\".", "They are numbered such that they can never throw a pair, and that the blue one will show a higher value than the red one exactly half the time.", "One such scheme could be 222555 on the red die and 333444 on the blue die.One card is dealt from the red deck and one is dealt from the blue deck.", "The shooter throws the \"cubes\" and the color of the cube that is higher selects the color of the card to be used to settle bets.", "On one such table, an additional one-roll prop bet was offered: If the card that was turned over for the \"roll\" was either 1–1 or 6–6, the other card was also turned over.", "If the other card was the \"opposite\" (6–6 or 1–1, respectively) of the first card, the bet paid 500:1 for this 647:1 proposition.And additional variation uses a single set of 6 cards, and regular dice.", "The roll of the dice maps to the card in that position, and if a pair is rolled, then the mapped card is used twice, as a pair." ], [ "Rules of play against other players (\"Street Craps\")", "Recreational or informal playing of craps outside of a casino is referred to as street craps or private craps.", "The most notable difference between playing street craps and bank craps is that there is no bank or house to cover bets in street craps.", "Players must bet against each other by covering or fading each other's bets for the game to be played.", "If money is used instead of chips and depending on the laws of where it is being played, street craps can be an illegal form of gambling.There are many variations of street craps.", "The simplest way is to either agree on or roll a number as the point, then roll the point again before rolling a seven.", "Unlike more complex proposition bets offered by casinos, street craps has more simplified betting options.", "The shooter is required to make either a Pass or a Don't Pass bet if he wants to roll the dice.", "Another player must choose to cover the shooter to create a stake for the game to continue.If there are several players, the rotation of the player who must cover the shooter may change with the shooter (comparable to a blind in poker).", "The person covering the shooter will always bet against the shooter.", "For example, if the shooter made a \"Pass\" bet, the person covering the shooter would make a \"Don't Pass\" bet to win.", "Once the shooter is covered, other players may make Pass/Don't Pass bets, or any other proposition bets, as long as there is another player willing to cover." ], [ "In popular culture", "Due to the random nature of the game, in popular culture a '''\"crapshoot\"''' is often used to describe an action with an unpredictable outcome.The prayer or invocation \"Baby needs a new pair of shoes!\"", "is associated with shooting craps.===Floating craps==='''Floating craps''' is an illegal operation of craps.", "The term ''floating'' refers to the practice of the game's operators using portable tables and equipment to quickly move the game from location to location to stay ahead of the law enforcement authorities.", "The term may have originated in the 1930s when Benny Binion (later known for founding the downtown Las Vegas hotel Binion's) set up an illegal craps game utilizing tables created from portable crates for the Texas Centennial Exposition.The 1950 Broadway musical ''Guys and Dolls'' features a major plot point revolving around a floating craps game.In the 1950s and 1960s The Sands Hotel in Las Vegas had a craps table that floated in the swimming pool, as a joke reference to the notoriety of the term.===Records===A Golden Arm is a craps player who rolls the dice for longer than one hour without losing.", "Likely the first known Golden Arm was Oahu native Stanley Fujitake, who rolled 118 times without sevening out in 3 hours and 6 minutes at the California Hotel and Casino on May 28, 1989.The current record for length of a \"hand\" (successive rounds won by the same shooter) is 154 rolls including 25 passes by Patricia DeMauro of New Jersey, lasting 4 hours and 18 minutes, at the Borgata in Atlantic City, New Jersey, on May 23–24, 2009.She bested by over an hour the record held for almost 20 years – that of Fujitake." ], [ "See also" ], [ "References" ], [ "External links", "* *" ] ]
wikipedia
[ [ "Carl von Clausewitz" ], [ "Introduction", "'''Carl Philipp Gottfried''' (or '''Gottlieb''') '''von Clausewitz''' (; 1 July 1780 – 16 November 1831) was a Prussian general and military theorist who stressed the \"moral\" (in modern terms meaning psychological) and political aspects of waging war.", "His most notable work, (''\"On War''\"), though unfinished at his death, is considered a seminal treatise on military strategy and science.Clausewitz was a realist in many different senses, including ''realpolitik'', and while in some respects a romantic, he also drew heavily on the rationalist ideas of the European Enlightenment.Clausewitz stressed the dialectical interaction of diverse factors, noting how unexpected developments unfolding under the \"fog of war\" (i.e., in the face of incomplete, dubious, and often erroneous information and great fear, doubt, and excitement) call for rapid decisions by alert commanders.", "He saw history as a vital check on erudite abstractions that did not accord with experience.", "In contrast to the early work of Antoine-Henri Jomini, he argued that war could not be quantified or reduced to mapwork, geometry, and graphs.", "Clausewitz had many aphorisms, of which the most famous is \"War is the continuation of policy with other means.\"", "(often misquoted as \"... by other means\")." ], [ "Name", "Clausewitz's Christian names are sometimes given in non-German sources as \"Karl\", \"Carl Philipp Gottlieb\", or \"Carl Maria\".", "He spelled his own given name with a \"C\" in order to identify with the classical Western tradition; writers who use \"Karl\" are often seeking to emphasize their German (rather than European) identity.", "\"Carl Philipp Gottfried\" appears on Clausewitz's tombstone.", "Nonetheless, sources such as military historian Peter Paret and ''Encyclopædia Britannica'' continue to use Gottlieb instead of Gottfried." ], [ "Life and military career", "Clausewitz was born on 1 July 1780 in Burg bei Magdeburg in the Prussian Duchy of Magdeburg as the fourth and youngest son of a family that made claims to a noble status which Carl accepted.", "Clausewitz's family claimed descent from the Barons of Clausewitz in Upper Silesia, though scholars question the connection.", "His grandfather, the son of a Lutheran pastor, had been a professor of theology.", "Clausewitz's father, once a lieutenant in the army of Frederick the Great, King of Prussia, held a minor post in the Prussian internal-revenue service.", "Clausewitz entered the Prussian military service at the age of twelve as a lance corporal, eventually attaining the rank of major general.Clausewitz served in the Rhine campaigns (1793–1794) including the siege of Mainz, when the Prussian Army invaded France during the French Revolution, and fought in the Napoleonic Wars from 1806 to 1815.He entered the ''Kriegsakademie'' (also cited as \"The German War School\", the \"Military Academy in Berlin\", and the \"Prussian Military Academy,\" later the \"War College\") in Berlin in 1801 (aged 21), probably studied the writings of the philosophers Immanuel Kant and/or Johann Gottlieb Fichte and Friedrich Schleiermacher and won the regard of General Gerhard von Scharnhorst, the future first chief-of-staff of the newly reformed Prussian Army (appointed 1809).", "Clausewitz, Hermann von Boyen (1771–1848) and Karl von Grolman (1777–1843) were among Scharnhorst's primary allies in his efforts to reform the Prussian army between 1807 and 1814.Clausewitz served during the Jena Campaign as aide-de-camp to Prince August.", "At the Battle of Jena-Auerstedt on 14 October 1806—when Napoleon invaded Prussia and defeated the Prussian-Saxon army commanded by Karl Wilhelm Ferdinand, Duke of Brunswick—he was captured, one of the 25,000 prisoners taken that day as the Prussian army disintegrated.", "He was 26.Clausewitz was held prisoner with his prince in France from 1807 to 1808.Returning to Prussia, he assisted in the reform of the Prussian army and state.", "Johann Gottlieb Fichte wrote ''On Machiavelli, as an Author, and Passages from His Writings'' in June 1807.", "(\"''Über Machiavell, als Schriftsteller, und Stellen aus seinen Schriften''\" ).", "Carl Clausewitz wrote an interesting and anonymous Letter to Fichte (1809) about his book on ''Machiavelli.''", "The letter was published in Fichte's ''Verstreute kleine Schriften'' 157–166.For an English translation of the letter see ''Carl von Clausewitz Historical and Political Writings'' Edited by: Peter Paret and D. Moran (1992).Marie von Clausewitz (née, Countess von Brühl)On 10 December 1810, he married the socially prominent Countess Marie von Brühl, whom he had first met in 1803.She was a member of the noble German Brühl family originating in Thuringia.", "The couple moved in the highest circles, socialising with Berlin's political, literary, and intellectual élite.", "Marie was well-educated and politically well-connected—she played an important role in her husband's career progress and intellectual evolution.", "She also edited, published, and introduced his collected works.Opposed to Prussia's enforced alliance with Napoleon, Clausewitz left the Prussian army and served in the Imperial Russian Army from 1812 to 1813 during the Russian campaign, taking part in the Battle of Borodino (1812).", "Like many Prussian officers serving in Russia, he joined the Russian–German Legion in 1813.In the service of the Russian Empire, Clausewitz helped negotiate the Convention of Tauroggen (1812), which prepared the way for the coalition of Prussia, Russia, and the United Kingdom that ultimately defeated Napoleon and his allies.In 1815 the Russian-German Legion became integrated into the Prussian Army and Clausewitz re-entered Prussian service as a colonel.", "He was soon appointed chief-of-staff of Johann von Thielmann's III Corps.", "In that capacity he served at the Battle of Ligny and the Battle of Wavre during the Waterloo campaign in 1815.An army led personally by Napoleon defeated the Prussians at Ligny (south of Mont-Saint-Jean and the village of Waterloo) on 16 June 1815, but they withdrew in good order.", "Napoleon's failure to destroy the Prussian forces led to his defeat a few days later at the Battle of Waterloo (18 June 1815), when the Prussian forces arrived on his right flank late in the afternoon to support the Anglo-Dutch-Belgian forces pressing his front.", "Napoleon had convinced his troops that the field grey uniforms were those of Marshal Grouchy's grenadiers.", "Clausewitz's unit fought heavily outnumbered at Wavre (18–19 June 1815), preventing large reinforcements from reaching Napoleon at Waterloo.", "After the war, Clausewitz served as the director of the ''Kriegsakademie'', where he served until 1830.In that year he returned to active duty with the army.", "Soon afterward, the outbreak of several revolutions around Europe and a crisis in Poland appeared to presage another major European war.", "Clausewitz was appointed chief of staff of the only army Prussia was able to mobilise in this emergency, which was sent to the Polish border.", "Its commander, Gneisenau, died of cholera (August 1831), and Clausewitz took command of the Prussian army's efforts to construct a to contain the great cholera outbreak (the first time cholera had appeared in modern heartland Europe, causing a continent-wide panic).", "Clausewitz himself died of the same disease shortly afterwards, on 16 November 1831.His widow edited, published, and wrote the introduction to his ''magnum opus'' on the philosophy of war in 1832.", "(He had started working on the text in 1816 but had not completed it.)", "She wrote the preface for ''On War'' and had published most of his collected works by 1835.She died in January 1836." ], [ "Theory of war", "Clausewitz was a professional combat soldier who was involved in numerous military campaigns, but he is famous primarily as a military theorist interested in the examination of war, utilising the campaigns of Frederick the Great and Napoleon as frames of reference for his work.", "He wrote a careful, systematic, philosophical examination of war in all its aspects.", "The result was his principal book, ''On War'', a major work on the philosophy of war.", "It was unfinished when Clausewitz died and contains material written at different stages in his intellectual evolution, producing some significant contradictions between different sections.", "The sequence and precise character of that evolution is a source of much debate as to the exact meaning behind some seemingly contradictory observations in discussions pertinent to the tactical, operational and strategic levels of war, for example (though many of these apparent contradictions are simply the result of his dialectical method).", "Clausewitz constantly sought to revise the text, particularly between 1827 and his departure on his last field assignments, to include more material on \"people's war\" and forms of war other than high-intensity warfare between states, but relatively little of this material was included in the book.", "Soldiers before this time had written treatises on various military subjects, but none had undertaken a great philosophical examination of war on the scale of those written by Clausewitz and Leo Tolstoy, both of whom were inspired by the events of the Napoleonic Era.Clausewitz's work is still studied today, demonstrating its continued relevance.", "More than sixteen major English-language books that focused specifically on his work were published between 2005 and 2014, whereas his 19th-century rival Jomini has faded from influence.", "The historian Lynn Montross said that this outcome \"may be explained by the fact that Jomini produced a system of war, Clausewitz a philosophy.", "The one has been outdated by new weapons, the other still influences the strategy behind those weapons.\"", "Jomini did not attempt to define war but Clausewitz did, providing (and dialectically comparing) a number of definitions.", "The first is his dialectical thesis: \"War is thus an act of force to compel our enemy to do our will.\"", "The second, often treated as Clausewitz's 'bottom line,' is in fact merely his dialectical antithesis: \"War is merely the continuation of policy with other means.\"", "The synthesis of his dialectical examination of the nature of war is his famous \"trinity,\" saying that war is \"a fascinating trinity—composed of primordial violence, hatred, and enmity, which are to be regarded as a blind natural force; the play of chance and probability, within which the creative spirit is free to roam; and its element of subordination, as an instrument of policy, which makes it subject to pure reason.\"", "Christopher Bassford says the best shorthand for Clausewitz's trinity should be something like \"violent emotion/chance/rational calculation.\"", "However, it is frequently presented as \"people/army/government,\" a misunderstanding based on a later paragraph in the same section.", "This misrepresentation was popularised by U.S. Army Colonel Harry Summers' Vietnam-era interpretation, facilitated by weaknesses in the 1976 Howard/Paret translation.The degree to which Clausewitz managed to revise his manuscript to reflect that synthesis is the subject of much debate.", "His final reference to war and ''Politik'', however, goes beyond his widely quoted antithesis: \"War is simply the continuation of political intercourse with the addition of other means.", "We deliberately use the phrase 'with the addition of other means' because we also want to make it clear that war in itself does not suspend political intercourse or change it into something entirely different.", "In essentials that intercourse continues, irrespective of the means it employs.", "The main lines along which military events progress, and to which they are restricted, are political lines that continue throughout the war into the subsequent peace.", "\"Clausewitz introduced systematic philosophical contemplation into Western military thinking, with powerful implications not only for historical and analytical writing but also for practical policy, military instruction, and operational planning.", "He relied on his own experiences, contemporary writings about Napoleon, and on deep historical research.", "His historiographical approach is evident in his first extended study, written when he was 25, of the Thirty Years' War.", "He rejects the Enlightenment's view of the war as a chaotic muddle and instead explains its drawn-out operations by the economy and technology of the age, the social characteristics of the troops, and the commanders' politics and psychology.", "In ''On War'', Clausewitz sees all wars as the sum of decisions, actions, and reactions in an uncertain and dangerous context, and also as a socio-political phenomenon.", "He also stressed the complex nature of war, which encompasses both the socio-political and the operational and stresses the primacy of state policy.", "(One should be careful not to limit his observations on war to war between states, however, as he certainly discusses other kinds of protagonists).The word \"strategy\" had only recently come into usage in modern Europe, and Clausewitz's definition is quite narrow: \"the use of engagements for the object of war\" (which many today would call \"the operational level\" of war).", "Clausewitz conceived of war as a political, social, and military phenomenon which might—depending on circumstances—involve the entire population of a political entity at war.", "In any case, Clausewitz saw military force as an instrument that states and other political actors use to pursue the ends of their policy, in a dialectic between opposing wills, each with the aim of imposing his policies and will upon his enemy.Clausewitz's emphasis on the inherent superiority of the defense suggests that habitual aggressors are likely to end up as failures.", "The inherent superiority of the defense obviously does not mean that the defender will always win, however: there are other asymmetries to be considered.", "He was interested in co-operation between the regular army and militia or partisan forces, or citizen soldiers, as one possible—sometimes the only—method of defense.", "In the circumstances of the Wars of the French Revolution and those with Napoleon, which were energised by a rising spirit of nationalism, he emphasised the need for states to involve their entire populations in the conduct of war.", "This point is especially important, as these wars demonstrated that such energies could be of decisive importance and for a time led to a democratisation of the armed forces much as universal suffrage democratised politics.While Clausewitz was intensely aware of the value of intelligence at all levels, he was also very skeptical of the accuracy of much military intelligence: \"Many intelligence reports in war are contradictory; even more are false, and most are uncertain....", "In short, most intelligence is false.\"", "This circumstance is generally described as part of the fog of war.", "Such skeptical comments apply only to intelligence at the tactical and operational levels; at the strategic and political levels he constantly stressed the requirement for the best possible understanding of what today would be called strategic and political intelligence.", "His conclusions were influenced by his experiences in the Prussian Army, which was often in an intelligence fog due partly to the superior abilities of Napoleon's system but even more simply to the nature of war.", "Clausewitz acknowledges that friction creates enormous difficulties for the realization of any plan, and the ''fog of war'' hinders commanders from knowing what is happening.", "It is precisely in the context of this challenge that he develops the concept of military genius, whose capabilities are seen above all in the execution of operations.", "'Military genius' is not simply a matter of intellect, but a combination of qualities of intellect, experience, personality, and temperament (and there are many possible such combinations) that create a very highly developed mental aptitude for the waging of war.===Principal ideas===Clausewitz as a young manKey ideas discussed in ''On War'' include:* the dialectical approach to military analysis* the methods of \"critical analysis\"* the economic profit-seeking logic of commercial enterprise is equally applicable to the waging of war and negotiating for peace* the nature of the balance-of-power mechanism* the relationship between political objectives and military objectives in war* the asymmetrical relationship between attack and defense* the nature of \"military genius\" (involving matters of personality and character, beyond intellect)* the \"fascinating trinity\" (''wunderliche Dreifaltigkeit'') of war* philosophical distinctions between \"absolute war,\" \"ideal war,\" and \"real war\"* in \"real war,\" the distinctive poles of a) limited objectives (political and/or military) and b) war to \"render the enemy helpless\"* the idea that war and its conduct belong fundamentally to the social realm rather than to the realms of art or science* \"strategy\" belongs primarily to the realm of art, but is constrained by quantitative analyses of political benefits versus military costs & losses* \"tactics\" belongs primarily to the realm of science (most obvious in the development of siege warfare)* the importance of \"moral forces\" (more than simply \"morale\") as opposed to quantifiable physical elements* the \"military virtues\" of professional armies (which do not necessarily trump the rather different virtues of other kinds of fighting forces)* conversely, the very real effects of a superiority in numbers and \"mass\"* the essential unpredictability of war* the \"fog of war\"* \"friction\" – the disparity between the ideal performance of units, organisations or systems and their actual performance in real-world scenarios (Book I, Chapter VII)* strategic and operational \"centers of gravity\"* the \"culminating point of the offensive\"* the \"culminating point of victory\"" ], [ "Interpretation and misinterpretation", "Clausewitz used a dialectical method to construct his argument, leading to frequent misinterpretation of his ideas.", "British military theorist B. H. Liddell Hart contends that the enthusiastic acceptance by the Prussian military establishment—especially Moltke the Elder, a former student of Clausewitz —of what they believed to be Clausewitz's ideas, and the subsequent widespread adoption of the Prussian military system worldwide, had a deleterious effect on military theory and practice, due to their egregious misinterpretation of his ideas:As described by Christopher Bassford, then-professor of strategy at the National War College of the United States:Another example of this confusion is the idea that Clausewitz was a proponent of total war as used in the Third Reich's propaganda in the 1940s.", "In fact, Clausewitz never used the term \"total war\": rather, he discussed \"absolute war,\" a concept which evolved into the much more abstract notion of \"ideal war\" discussed at the very beginning of —the purely ''logical'' result of the forces underlying a \"pure,\" Platonic \"ideal\" of war.", "In what he called a \"logical fantasy,\" war cannot be waged in a limited way: the rules of competition will force participants to use all means at their disposal to achieve victory.", "But in the ''real world,'' he said, such rigid logic is unrealistic and dangerous.", "As a practical matter, the military objectives in ''real'' war that support political objectives generally fall into two broad types: limited aims or the effective \"disarming\" of the enemy \"to render him politically helpless or militarily impotent.", "Thus, the complete defeat of the enemy may not be necessary, desirable, or even possible.In modern times the reconstruction of Clausewitzian theory has been a matter of much dispute.", "One analysis was that of Panagiotis Kondylis, a Greek writer and philosopher, who opposed the interpretations of Raymond Aron in ''Penser la Guerre, Clausewitz,'' and other liberal writers.", "According to Aron, Clausewitz was one of the first writers to condemn the militarism of the Prussian general staff and its war-proneness, based on Clausewitz's argument that \"war is a continuation of policy by other means.\"", "In ''Theory of War,'' Kondylis claims that this is inconsistent with Clausewitzian thought.", "He claims that Clausewitz was morally indifferent to war (though this probably reflects a lack of familiarity with personal letters from Clausewitz, which demonstrate an acute awareness of war's tragic aspects) and that his advice regarding politics' dominance over the conduct of war has nothing to do with pacifist ideas.Other notable writers who have studied Clausewitz's texts and translated them into English are historians Peter Paret of the Institute for Advanced Study and Sir Michael Howard.", "Howard and Paret edited the most widely used edition of ''On War'' (Princeton University Press, 1976/1984) and have produced comparative studies of Clausewitz and other theorists, such as Tolstoy.", "Bernard Brodie's ''A Guide to the Reading of \"On War,\"'' in the 1976 Princeton translation, expressed his interpretations of the Prussian's theories and provided students with an influential synopsis of this vital work.", "The 1873 translation by Colonel James John Graham was heavily—and controversially—edited by the philosopher, musician, and game theorist Anatol Rapoport.The British military historian John Keegan attacked Clausewitz's theory in his book ''A History of Warfare''.", "Keegan argued that Clausewitz assumed the existence of states, yet 'war antedates the state, diplomacy and strategy by many millennia.'" ], [ "Influence", "Clausewitz died without completing ''Vom Kriege,'' but despite this his ideas have been widely influential in military theory and have had a strong influence on German military thought specifically.", "Later Prussian and German generals, such as Helmuth Graf von Moltke, were clearly influenced by Clausewitz: Moltke's widely quoted statement that \"No operational plan extends with high certainty beyond the first encounter with the main enemy force\" is a classic reflection of Clausewitz's insistence on the roles of chance, friction, \"fog,\" uncertainty, and interactivity in war.Clausewitz's influence spread to British thinking as well, though at first more as a historian and analyst than as a theorist.", "See for example Wellington's extended essay discussing Clausewitz's study of the Campaign of 1815—Wellington's only serious written discussion of the battle, which was widely discussed in 19th-century Britain.", "Clausewitz's broader thinking came to the fore following Britain's military embarrassments in the Boer War (1899–1902).", "One example of a heavy Clausewitzian influence in that era is Spenser Wilkinson, journalist, the first Chichele Professor of Military History at Oxford University, and perhaps the most prominent military analyst in Britain from until well into the interwar period.", "Another is naval historian Julian Corbett (1854–1922), whose work reflected a deep if idiosyncratic adherence to Clausewitz's concepts and frequently an emphasis on Clausewitz's ideas about 'limited objectives' and the inherent strengths of the defensive form of war.", "Corbett's practical strategic views were often in prominent public conflict with Wilkinson's—see, for example, Wilkinson's article \"Strategy at Sea\", ''The Morning Post'', 12 February 1912.Following the First World War, however, the influential British military commentator B. H. Liddell Hart in the 1920s erroneously attributed to him the doctrine of \"total war\" that during the First World War had been embraced by many European general staffs and emulated by the British.", "More recent scholars typically see that war as so confused in terms of political rationale that it in fact contradicts much of ''On War.''", "That view assumes, however, a set of values as to what constitutes \"rational\" political objectives—in this case, values not shaped by the fervid Social Darwinism that was rife in 1914 Europe.", "One of the most influential British Clausewitzians today is Colin S. Gray; historian Hew Strachan (like Wilkinson also the Chichele Professor of Military History at Oxford University, since 2001) has been an energetic proponent of the ''study'' of Clausewitz, but his own views on Clausewitz's ideas are somewhat ambivalent.With some interesting exceptions (e.g., John McAuley Palmer, Robert M. Johnston, Hoffman Nickerson), Clausewitz had little influence on American military thought before 1945 other than via British writers, though Generals Eisenhower and Patton were avid readers of English translations.", "He did influence Karl Marx, Friedrich Engels, Vladimir Lenin, Leon Trotsky, Võ Nguyên Giáp, Ferdinand Foch, and Mao Zedong, and thus the Communist Soviet and Chinese traditions, as Lenin emphasized the inevitability of wars among capitalist states in the age of imperialism and presented the armed struggle of the working class as the only path toward the eventual elimination of war.", "Because Lenin was an admirer of Clausewitz and called him \"one of the great military writers,\" his influence on the Red Army was immense.", "The Russian historian A.N.", "Mertsalov commented that \"It was an irony of fate that the view in the USSR was that it was Lenin who shaped the attitude towards Clausewitz, and that Lenin's dictum that war is a continuation of politics is taken from the work of this allegedly anti-humanist anti-revolutionary.\"", "The American mathematician Anatol Rapoport wrote in 1968 that Clausewitz as interpreted by Lenin formed the basis of all Soviet military thinking since 1917, and quoted the remarks by Marshal V.D.", "Sokolovsky:Henry A. Kissinger, however, described Lenin's approach as being that politics is a continuation of war by other means, thus turning Clausewitz's argument \"on its head.", "\"Rapoport argued that:Clausewitz directly influenced Mao Zedong, who read ''On War'' in 1938 and organised a seminar on Clausewitz for the Party leadership in Yan'an.", "Thus the \"Clausewitzian\" content in many of Mao's writings is not merely a regurgitation of Lenin but reflects Mao's own study.", "The idea that war involves inherent \"friction\" that distorts, to a greater or lesser degree, all prior arrangements, has become common currency in fields such as business strategy and sport.", "The phrase ''fog of war'' derives from Clausewitz's stress on how confused warfare can seem while one is immersed within it.", "The term center of gravity, used in a military context derives from Clausewitz's usage, which he took from Newtonian mechanics.", "In U.S. military doctrine, \"center of gravity\" refers to the basis of an opponent's power at the operational, strategic, or political level, though this is only one aspect of Clausewitz's use of the term.===Late 20th and early 21st century===The deterrence strategy of the United States in the 1950s was closely inspired by President Dwight Eisenhower's reading of Clausewitz as a young officer in the 1920s.", "Eisenhower was greatly impressed by Clausewitz's example of a theoretical, idealized \"absolute war\" in ''Vom Kriege'' as a way of demonstrating how absurd it would be to attempt such a strategy in practice.", "For Eisenhower, the age of nuclear weapons had made what was for Clausewitz in the early 19th century only a theoretical vision an all too real possibility in the mid-20th century.", "From Eisenhower's viewpoint, the best deterrent to war was to show the world just how appalling and horrific a nuclear \"absolute war\" would be if it should ever occur, hence a series of much publicized nuclear tests in the Pacific, giving first priority in the defense budget to nuclear weapons and delivery systems over conventional weapons, and making repeated statements in public that the United States was able and willing at all times to use nuclear weapons.", "In this way, through the massive retaliation doctrine and the closely related foreign policy concept of brinkmanship, Eisenhower hoped to hold out a credible vision of Clausewitzian nuclear \"absolute war\" in order to deter the Soviet Union and/or China from ever risking a war or even conditions that might lead to a war with the United States.After 1970, some theorists claimed that nuclear proliferation made Clausewitzian concepts obsolete after the 20th-century period in which they dominated the world.", "John E. Sheppard, Jr., argues that by developing nuclear weapons, state-based conventional armies simultaneously both perfected their original purpose, to destroy a mirror image of themselves, and made themselves obsolete.", "No two powers have used nuclear weapons against each other, instead using diplomacy, conventional means, or proxy wars to settle disputes.", "If such a conflict did occur, presumably both combatants would be annihilated.", "Heavily influenced by the war in Vietnam and by antipathy to American strategist Henry Kissinger, the American biologist, musician, and game-theorist Anatol Rapoport argued in 1968 that a Clausewitzian view of war was not only obsolete in the age of nuclear weapons, but also highly dangerous as it promoted a \"zero-sum paradigm\" to international relations and a \"dissolution of rationality\" amongst decision-makers.The end of the 20th century and the beginning of the 21st century have seen many instances of state armies attempting to suppress insurgencies, terrorism, and other forms of asymmetrical warfare.", "Clausewitz did not focus solely on wars between countries with well-defined armies.", "The era of the French Revolution and Napoleon was full of revolutions, rebellions, and violence by \"non-state actors,\" such as the wars in the French Vendée and in Spain.", "Clausewitz wrote a series of \"Lectures on Small War\" and studied the rebellion in the Vendée (1793–1796) and the Tyrolean uprising of 1809.In his famous \"Bekenntnisdenkschrift\" of 1812, he called for a \"Spanish war in Germany\" and laid out a comprehensive guerrilla strategy to be waged against Napoleon.", "In ''On War'' he included a famous chapter on \"The People in Arms.", "\"One prominent critic of Clausewitz is the Israeli military historian Martin van Creveld.", "In his book ''The Transformation of War'', Creveld argued that Clausewitz's famous \"Trinity\" of people, army, and government was an obsolete socio-political construct based on the state, which was rapidly passing from the scene as the key player in war, and that he (Creveld) had constructed a new \"non-trinitarian\" model for modern warfare.", "Creveld's work has had great influence.", "Daniel Moran replied, 'The most egregious misrepresentation of Clausewitz's famous metaphor must be that of Martin van Creveld, who has declared Clausewitz to be an apostle of Trinitarian War, by which he means, incomprehensibly, a war of 'state against state and army against army,' from which the influence of the people is entirely excluded.\"", "Christopher Bassford went further, noting that one need only ''read'' the paragraph in which Clausewitz defined his Trinity to see \"that the words 'people,' 'army,' and 'government' appear nowhere at all in the list of the Trinity's components.... Creveld's and Keegan's assault on Clausewitz's Trinity is not only a classic 'blow into the air,' i.e., an assault on a position Clausewitz doesn't occupy.", "It is also a pointless attack on a concept that is quite useful in its own right.", "In any case, their failure to read the actual wording of the theory they so vociferously attack, and to grasp its deep relevance to the phenomena they describe, is hard to credit.", "\"Some have gone further and suggested that Clausewitz's best-known aphorism, that war is a continuation of policy with other means, is not only irrelevant today but also inapplicable historically.", "For an opposing view see the sixteen essays presented in ''Clausewitz in the Twenty-First Century'' edited by Hew Strachan and Andreas Herberg-Rothe.In military academies, schools, and universities worldwide, Clausewitz's ''Vom Kriege'' is often (usually in translation) mandatory reading." ], [ "See also", "August Otto Rühle von Lilienstern – Prussian officer from whom Clausewitz allegedly took, without acknowledgement, several important ideas (including that about war as pursuing political aims) made famous in ''On War''.", "However, substantial basis for assuming common influences exist, most prominently Scharnhorst, who was Clausewitz's \"second father\" and professional mentor.", "This provokes skepticism of the claim the ideas were plagiarized from Lilienstern.", "* Famous military writers** Niccolò Machiavelli – ''The Prince''** Antoine-Henri Jomini** B.H.", "Liddell Hart** Sun Tzu** Maurice de Saxe* Absolute war* Operation Clausewitz* Philosophy of war* Principles of War* Strategic studies* Total war* U.S. Army Strategist" ], [ "References", "'''Informational notes''''''Citations'''" ], [ "Further reading", "* See massive Clausewitz bibliographies in English, French, German, etc., on ''The Clausewitz Homepage'' bibliography section.", "* Aron, Raymond.", "''Clausewitz: Philosopher of War.''", "(1985).", "418 pp.", "* Bassford, Christopher. ''", "Clausewitz in English: The Reception of Clausewitz in Britain and America, 1815–1945.''", "New York: Oxford University Press, 1994.", "* Christopher Bassford, \" Tiptoe Through the Trinity: The Strange Persistence of Trinitarian Warfare.\"", "Working paper.", "* Christopher Bassford, \" Clausewitz's Categories of War and the Supersession of 'Absolute War' \" (Clausewitz.com).", "This is a 'working paper' first posted in 2016.", "\"* * Cormier, Youri.", "\"Fighting Doctrines and Revolutionary Ethics\" Journal of Military and Security Studies, Vol 15, No 1 (2013) https://web.archive.org/web/20140729225332/http://jmss.synergiesprairies.ca/jmss/index.php/jmss/article/view/519* * Cormier, Youri.", "War As Paradox: Clausewitz & Hegel on Fighting Doctrines and Ethics, (Montreal & Kingston: McGill Queen's University Press, 2016) pp.", "183–232* * Donker, Paul. \"", "The Evolution of Clausewitz's ''Vom Kriege'': a reconstruction on the basis of the earlier versions of his masterpiece.\"", "Trans.", "Paul Donker and Christopher Bassford, ClausewitzStudies.org, August 2019.Originally \"Die Entwicklung von Clausewitz' Vom Kriege: Eine Rekonstruktion auf der Grundlage der früheren Fassungen seines Meisterwerks,\" in the Clausewitz-Gesellschaft's Jahrbuch2017, pp. 14–39.", "* Echevarria, Antulio J., II.", "''After Clausewitz: German Military Thinkers before the Great War.''", "(2001).", "346 pp.", "* * Gat, Azar.", "''The Origins of Military Thought from the Enlightenment to Clausewitz'' (1989) * Handel, Michael I., ed.", "''Clausewitz and Modern Strategy.''", "1986.324 pp.", "* Handel, Michael I.", "''Masters of War: Classical Strategic Thought.''", "(2001) 482 pages.", "Based on comparison of Clausewitz's ''On War'' with Sun Tzu's ''The Art of War'' * Heuser, Beatrice.", "''Reading Clausewitz.''", "(2002).", "238 pages, * * * Sir Michael Howard, ''Clausewitz'', 1983 originally a volume in the Oxford University Press \"Past Masters\" series, reissued in 2000 as ''Clausewitz: A Very Short Introduction''.", "* ** See critique of Keegan's arguments by Christopher Bassford, \" John Keegan and the Grand Tradition of Trashing Clausewitz: A Polemic,\" ''War in History'', November 1994, pp. 319–336.", "* * * Mertsalov, A.N.", "\"Jomini versus Clausewitz\" pp.", "11–19 from ''Russia War, Peace and Diplomacy'' edited by Mark and Ljubica Erickson, London: Weidenfeld & Nicolson, 2004, .", "* Paret, Peter.", "in His Time: Essays in the Cultural and Intellectual History of Thinking about War''.", "New York and Oxford: Berghahn Books, 2015.", "* * Paret, Peter.", "''Clausewitz and the State: The Man, His Theories, and His Times''.", "Princeton: Princeton University Press, 1976.", "* * * Paul Roques, Le général de Clausewitz.", "Sa vie et sa théorie de la guerre, Paris, Editions Astrée, 2013.http://www.editions-astree.fr/BC/Bon_de_commande_Roques.pdf* Rothfels, Hans \"Clausewitz\" pp.", "93–113 from ''The Makers of Modern Strategy'' edited by Edward Mead Earle, Gordon A. Craig & Felix Gilbert, Princeton, N.J.: Princeton University Press, 1943.", "* * Smith, Hugh.", "''On Clausewitz: A Study of Military and Political Ideas.''", "(2005).", "303 pp.", "* Stoker, Donald J.", "''Clausewitz: His Life and Work'' (Oxford UP, 2014) 376 pp.", "online review; also excerpt* * Strachan, Hew, and Andreas Herberg-Rothe, eds.", "''Clausewitz in the Twenty-First Century'' (2007) excerpt and text search* * Sumida, Jon Tetsuro.", "''Decoding Clausewitz: A New Approach to On War'' Lawrence, Kansas: University Press of Kansas, 2008.", "* Villacres, Edward J. and Bassford, Christopher.", "\"Reclaiming the Clausewitzian Trinity\".", "Parameters, Autumn 95, pp.", "9–19,* Wallach, Jehuda L. ''The Dogma of the Battle of Annihilation: The Theories of Clausewitz and Schlieffen and Their Impact on the German Conduct of Two World Wars.''", "(1986).", "* ===Primary sources (including translations)===* Clausewitz, Carl von.", "''Historical and Political Writings,'' ed.", "Peter Paret and Daniel Moran (1992).", "* Clausewitz, Carl von. ''", "Vom Kriege''.", "Berlin: Dümmlers Verlag, 1832.", "* * Clausewitz, Carl von.", "''On War'', abridged version translated by Michael Howard and Peter Paret, edited with an introduction by Beatrice Heuser Oxford World's Classics (Oxford University Press, 2007) * Clausewitz, Carl von. ''", "Principles of War''.", "Translated by Hans Gatske.", "The Military Service Publishing Company, 1942.Originally \"Die wichtigsten Grundsätze des Kriegführens zur Ergänzung meines Unterrichts bei Sr. Königlichen Hoheit dem Kronprinzen\" (written 1812).", "* Clausewitz, Carl von.", "Col. J. J. Graham, translator.", "''Vom Kriege''. ''", "On War – Volume 1'', Project Gutenberg eBook.", "The ''full'' text of the 1873 English translation can be seen in parallel with the original German text at Compare VOM KRIEGE (1832) and ON WAR (1873 translation) .", "Compare VOM KRIEGE (1832) and ON WAR (1873 translation) * Clausewitz, Karl von.", "''On War.''", "Trans.", "O.J.", "Matthijs Jolles.", "New York: Random House, 1943.Though not currently the standard translation, this is increasingly viewed by many Clausewitz scholars as the most precise and accurate English translation.", "* Clausewitz, Carl von (2018).", "''Napoleon's 1796 Italian Campaign.''", "Trans and ed.", "Nicholas Murray and Christopher Pringle.", "Lawrence, Kansas: University Press of Kansas.", "* Clausewitz, Carl von (2020).", "''Napoleon Absent, Coalition Ascendant: The 1799 Campaign in Italy and Switzerland, Volume 1.''", "Trans and ed.", "Nicholas Murray and Christopher Pringle.", "Lawrence, Kansas: University Press of Kansas.", "online review* Clausewitz, Carl von (2021).", "''The Coalition Crumbles, Napoleon Returns: The 1799 Campaign in Italy and Switzerland, Volume 2.''", "Trans and ed.", "Nicholas Murray and Christopher Pringle.", "Lawrence, Kansas: University Press of Kansas.", "* Clausewitz, Carl von. ''", "''The Campaign of 1812 in Russia'' ''.", "Trans.", "anonymous Wellington's friend Francis Egerton, later Lord Ellesmere, London: John Murray Publishers, 1843.Originally Carl von Clausewitz, ''Hinterlassene Werke des Generals Carl von Clausewitz über Krieg und Krieg führung'', 10 vols., Berlin, 1832–37, \"''Der Feldzug von 1812 in Russland''\" in Vol.", "7, Berlin, 1835.", "* Clausewitz, Carl von, and Wellesley, Arthur (First Duke of Wellington), ed./trans.", "Christopher Bassford, Gregory W. Pedlow, and Daniel Moran, ''On Waterloo: Clausewitz, Wellington, and the Campaign of 1815''.", "(Clausewitz.com, 2010).", "This collection of documents includes, in a modern English translation, the whole of Clausewitz's study, '' The Campaign of 1815: Strategic Overview'' (Berlin: 1835).", ".", "It also includes Wellington's reply to Clausewitz's discussion of the campaign, as well as two letters by Clausewitz to his wife after the major battles of 1815 and other supporting documents and essays.", "* Clausewitz, Carl von. ''", "Two Letters on Strategy''.", "Ed./trans.", "Peter Paret and Daniel Moran.", "Carlisle: Army War College Foundation, 1984." ], [ "External links", "* Mind Map of ''On War''* Clausewitz homepage, large amounts of information.", "* Corn, Tony.", "\"Clausewitz in Wonderland\", ''Policy Review'', September 2006.This is an article hostile to \"Clausewitz and the Clausewitzians.\"", "See also reply by Clausewitz Homepage, \"Clausewitz's self-appointed PR Flack.", "\"* * * * The Influence of Clausewitz on Jomini's Le Précis de l'Art de la Guerre* ''Two Letters On Strategy'', addressed to the Prussian general-staff officer, Major von Roeder, respectively of 22 and 24 December 1827.", "* Erfourth M. & Bazin, A.", "(2014).", "Clausewitz's Military Genius and the #Human Dimension.", "The Bridge." ] ]
wikipedia
[ [ "Common Lisp" ], [ "Introduction", "'''Common Lisp''' ('''CL''') is a dialect of the Lisp programming language, published in American National Standards Institute (ANSI) standard document ''ANSI INCITS 226-1994 (S2018)'' (formerly ''X3.226-1994 (R1999)'').", "The Common Lisp HyperSpec, a hyperlinked HTML version, has been derived from the ANSI Common Lisp standard.The Common Lisp language was developed as a standardized and improved successor of Maclisp.", "By the early 1980s several groups were already at work on diverse successors to MacLisp: Lisp Machine Lisp (aka ZetaLisp), Spice Lisp, NIL and S-1 Lisp.", "Common Lisp sought to unify, standardise, and extend the features of these MacLisp dialects.", "Common Lisp is not an implementation, but rather a language specification.", "Several implementations of the Common Lisp standard are available, including free and open-source software and proprietary products.Common Lisp is a general-purpose, multi-paradigm programming language.", "It supports a combination of procedural, functional, and object-oriented programming paradigms.", "As a dynamic programming language, it facilitates evolutionary and incremental software development, with iterative compilation into efficient run-time programs.", "This incremental development is often done interactively without interrupting the running application.It also supports optional type annotation and casting, which can be added as necessary at the later profiling and optimization stages, to permit the compiler to generate more efficient code.", "For instance, fixnum can hold an unboxed integer in a range supported by the hardware and implementation, permitting more efficient arithmetic than on big integers or arbitrary precision types.", "Similarly, the compiler can be told on a per-module or per-function basis which type of safety level is wanted, using ''optimize'' declarations.Common Lisp includes CLOS, an object system that supports multimethods and method combinations.", "It is often implemented with a Metaobject Protocol.Common Lisp is extensible through standard features such as ''Lisp macros'' (code transformations) and ''reader macros'' (input parsers for characters).Common Lisp provides partial backwards compatibility with Maclisp and John McCarthy's original Lisp.", "This allows older Lisp software to be ported to Common Lisp." ], [ "History", "Work on Common Lisp started in 1981 after an initiative by ARPA manager Bob Engelmore to develop a single community standard Lisp dialect.", "Much of the initial language design was done via electronic mail.", "In 1982, Guy L. Steele Jr. gave the first overview of Common Lisp at the 1982 ACM Symposium on LISP and functional programming.The first language documentation was published in 1984 as Common Lisp the Language (known as CLtL1), first edition.", "A second edition (known as CLtL2), published in 1990, incorporated many changes to the language, made during the ANSI Common Lisp standardization process: extended LOOP syntax, the Common Lisp Object System, the Condition System for error handling, an interface to the pretty printer and much more.", "But CLtL2 does not describe the final ANSI Common Lisp standard and thus is not a documentation of ANSI Common Lisp.", "The final ANSI Common Lisp standard then was published in 1994.Since then no update to the standard has been published.", "Various extensions and improvements to Common Lisp (examples are Unicode, Concurrency, CLOS-based IO) have been provided by implementations and libraries." ], [ "Syntax", "Common Lisp is a dialect of Lisp.", "It uses S-expressions to denote both code and data structure.", "Function calls, macro forms and special forms are written as lists, with the name of the operator first, as in these examples: (+ 2 2) ; adds 2 and 2, yielding 4.The function's name is '+'.", "Lisp has no operators as such.", "(defvar *x*) ; Ensures that a variable *x* exists, ; without giving it a value.", "The asterisks are part of ; the name, by convention denoting a special (global) variable.", "; The symbol *x* is also hereby endowed with the property that ; subsequent bindings of it are dynamic, rather than lexical.", "(setf *x* 42.1) ; Sets the variable *x* to the floating-point value 42.1 ;; Define a function that squares a number: (defun square (x) (* x x)) ;; Execute the function: (square 3) ; Returns 9 ;; The 'let' construct creates a scope for local variables.", "Here ;; the variable 'a' is bound to 6 and the variable 'b' is bound ;; to 4.Inside the 'let' is a 'body', where the last computed value is returned.", ";; Here the result of adding a and b is returned from the 'let' expression.", ";; The variables a and b have lexical scope, unless the symbols have been ;; marked as special variables (for instance by a prior DEFVAR).", "(let ((a 6) (b 4)) (+ a b)) ; returns 10" ], [ "Data types", "Common Lisp has many data types.===Scalar types===''Number'' types include integers, ratios, floating-point numbers, and complex numbers.", "Common Lisp uses bignums to represent numerical values of arbitrary size and precision.", "The ratio type represents fractions exactly, a facility not available in many languages.", "Common Lisp automatically coerces numeric values among these types as appropriate.The Common Lisp ''character'' type is not limited to ASCII characters.", "Most modern implementations allow Unicode characters.The ''symbol'' type is common to Lisp languages, but largely unknown outside them.", "A symbol is a unique, named data object with several parts: name, value, function, property list, and package.", "Of these, ''value cell'' and ''function cell'' are the most important.", "Symbols in Lisp are often used similarly to identifiers in other languages: to hold the value of a variable; however there are many other uses.", "Normally, when a symbol is evaluated, its value is returned.", "Some symbols evaluate to themselves, for example, all symbols in the keyword package are self-evaluating.", "Boolean values in Common Lisp are represented by the self-evaluating symbols T and NIL.", "Common Lisp has namespaces for symbols, called 'packages'.A number of functions are available for rounding scalar numeric values in various ways.", "The function round rounds the argument to the nearest integer, with halfway cases rounded to the even integer.", "The functions truncate, floor, and ceiling round towards zero, down, or up respectively.", "All these functions return the discarded fractional part as a secondary value.", "For example, (floor -2.5) yields −3, 0.5; (ceiling -2.5) yields −2, −0.5; (round 2.5) yields 2, 0.5; and (round 3.5) yields 4, −0.5.===Data structures===''Sequence'' types in Common Lisp include lists, vectors, bit-vectors, and strings.", "There are many operations that can work on any sequence type.As in almost all other Lisp dialects, ''lists'' in Common Lisp are composed of ''conses'', sometimes called ''cons cells'' or ''pairs''.", "A cons is a data structure with two slots, called its ''car'' and ''cdr''.", "A list is a linked chain of conses or the empty list.", "Each cons's car refers to a member of the list (possibly another list).", "Each cons's cdr refers to the next cons—except for the last cons in a list, whose cdr refers to the nil value.", "Conses can also easily be used to implement trees and other complex data structures; though it is usually advised to use structure or class instances instead.", "It is also possible to create circular data structures with conses.Common Lisp supports multidimensional ''arrays'', and can dynamically resize ''adjustable'' arrays if required.", "Multidimensional arrays can be used for matrix mathematics.", "A ''vector'' is a one-dimensional array.", "Arrays can carry any type as members (even mixed types in the same array) or can be specialized to contain a specific type of members, as in a vector of bits.", "Usually, only a few types are supported.", "Many implementations can optimize array functions when the array used is type-specialized.", "Two type-specialized array types are standard: a ''string'' is a vector of characters, while a ''bit-vector'' is a vector of bits.", "''Hash tables'' store associations between data objects.", "Any object may be used as key or value.", "Hash tables are automatically resized as needed.", "''Packages'' are collections of symbols, used chiefly to separate the parts of a program into namespaces.", "A package may ''export'' some symbols, marking them as part of a public interface.", "Packages can use other packages.", "''Structures'', similar in use to C structs and Pascal records, represent arbitrary complex data structures with any number and type of fields (called ''slots'').", "Structures allow single-inheritance.", "''Classes'' are similar to structures, but offer more dynamic features and multiple-inheritance.", "(See CLOS).", "Classes have been added late to Common Lisp and there is some conceptual overlap with structures.", "Objects created of classes are called ''Instances''.", "A special case is Generic Functions.", "Generic Functions are both functions and instances.===Functions===Common Lisp supports first-class functions.", "For instance, it is possible to write functions that take other functions as arguments or return functions as well.", "This makes it possible to describe very general operations.The Common Lisp library relies heavily on such higher-order functions.", "For example, the sort function takes a relational operator as an argument and key function as an optional keyword argument.", "This can be used not only to sort any type of data, but also to sort data structures according to a key.", ";; Sorts the list using the > and ) ; Returns (6 5 4 3 2 1) (sort (list 5 2 6 3 1 4) #' ;; Sorts the list according to the first element of each sub-list.", "(sort (list '(9 A) '(3 B) '(4 C)) #'The evaluation model for functions is very simple.", "When the evaluator encounters a form (f a1 a2...) then it presumes that the symbol named f is one of the following:# A special operator (easily checked against a fixed list)# A macro operator (must have been defined previously)# The name of a function (default), which may either be a symbol, or a sub-form beginning with the symbol lambda.If f is the name of a function, then the arguments a1, a2, ..., an are evaluated in left-to-right order, and the function is found and invoked with those values supplied as parameters.====Defining functions====The macro defun defines functions where a function definition gives the name of the function, the names of any arguments, and a function body: (defun square (x) (* x x))Function definitions may include compiler directives, known as ''declarations'', which provide hints to the compiler about optimization settings or the data types of arguments.", "They may also include ''documentation strings'' (docstrings), which the Lisp system may use to provide interactive documentation: (defun square (x) \"Calculates the square of the single-float x.\"", "(declare (single-float x) (optimize (speed 3) (debug 0) (safety 1))) (the single-float (* x x)))Anonymous functions (function literals) are defined using lambda expressions, e.g.", "(lambda (x) (* x x)) for a function that squares its argument.", "Lisp programming style frequently uses higher-order functions for which it is useful to provide anonymous functions as arguments.Local functions can be defined with flet and labels.", "(flet ((square (x) (* x x))) (square 3))There are several other operators related to the definition and manipulation of functions.", "For instance, a function may be compiled with the compile operator.", "(Some Lisp systems run functions using an interpreter by default unless instructed to compile; others compile every function).====Defining generic functions and methods====The macro defgeneric defines generic functions.", "Generic functions are a collection of methods.The macro defmethod defines methods.Methods can specialize their parameters over CLOS ''standard classes'', ''system classes'', ''structure classes'' or individual objects.", "For many types, there are corresponding ''system classes''.When a generic function is called, multiple-dispatch will determine the effective method to use.", "(defgeneric add (a b)) (defmethod add ((a number) (b number)) (+ a b)) (defmethod add ((a vector) (b number)) (map 'vector (lambda (n) (+ n b)) a)) (defmethod add ((a vector) (b vector)) (map 'vector #'+ a b))(defmethod add ((a string) (b string)) (concatenate 'string a b)) (add 2 3) ; returns 5 (add #(1 2 3 4) 7) ; returns #(8 9 10 11) (add #(1 2 3 4) #(4 3 2 1)) ; returns #(5 5 5 5) (add \"COMMON \" \"LISP\") ; returns \"COMMON LISP\"Generic Functions are also a first class data type.", "There are many more features to Generic Functions and Methods than described above.====The function namespace====The namespace for function names is separate from the namespace for data variables.", "This is a key difference between Common Lisp and Scheme.", "For Common Lisp, operators that define names in the function namespace include defun, flet, labels, defmethod and defgeneric.To pass a function by name as an argument to another function, one must use the function special operator, commonly abbreviated as #'.", "The first sort example above refers to the function named by the symbol > in the function namespace, with the code #'>.", "Conversely, to call a function passed in such a way, one would use the funcall operator on the argument.Scheme's evaluation model is simpler: there is only one namespace, and all positions in the form are evaluated (in any order) – not just the arguments.", "Code written in one dialect is therefore sometimes confusing to programmers more experienced in the other.", "For instance, many Common Lisp programmers like to use descriptive variable names such as ''list'' or ''string'' which could cause problems in Scheme, as they would locally shadow function names.Whether a separate namespace for functions is an advantage is a source of contention in the Lisp community.", "It is usually referred to as the ''Lisp-1 vs. Lisp-2 debate''.", "Lisp-1 refers to Scheme's model and Lisp-2 refers to Common Lisp's model.", "These names were coined in a 1988 paper by Richard P. Gabriel and Kent Pitman, which extensively compares the two approaches.====Multiple return values====Common Lisp supports the concept of ''multiple values'', where any expression always has a single ''primary value'', but it might also have any number of ''secondary values'', which might be received and inspected by interested callers.", "This concept is distinct from returning a list value, as the secondary values are fully optional, and passed via a dedicated side channel.", "This means that callers may remain entirely unaware of the secondary values being there if they have no need for them, and it makes it convenient to use the mechanism for communicating information that is sometimes useful, but not always necessary.", "For example,* The TRUNCATE function rounds the given number to an integer towards zero.", "However, it also returns a remainder as a secondary value, making it very easy to determine what value was truncated.", "It also supports an optional divisor parameter, which can be used to perform Euclidean division trivially:(let ((x 1266778) (y 458)) (multiple-value-bind (quotient remainder) (truncate x y) (format nil \"~A divided by ~A is ~A remainder ~A\" x y quotient remainder)));;;; => \"1266778 divided by 458 is 2765 remainder 408\"* GETHASH returns the value of a key in an associative map, or the default value otherwise, and a secondary boolean indicating whether the value was found.", "Thus code which does not care about whether the value was found or provided as the default can simply use it as-is, but when such distinction is important, it might inspect the secondary boolean and react appropriately.", "Both use cases are supported by the same call and neither is unnecessarily burdened or constrained by the other.", "Having this feature at the language level removes the need to check for the existence of the key or compare it to null as would be done in other languages.", "(defun get-answer (library) (gethash 'answer library 42))(defun the-answer-1 (library) (format nil \"The answer is ~A\" (get-answer library)));;;; Returns \"The answer is 42\" if ANSWER not present in LIBRARY(defun the-answer-2 (library) (multiple-value-bind (answer sure-p) (get-answer library) (if (not sure-p) \"I don't know\" (format nil \"The answer is ~A\" answer))));;;; Returns \"I don't know\" if ANSWER not present in LIBRARYMultiple values are supported by a handful of standard forms, most common of which are the MULTIPLE-VALUE-BIND special form for accessing secondary values and VALUES for returning multiple values:(defun magic-eight-ball () \"Return an outlook prediction, with the probability as a secondary value\" (values \"Outlook good\" (random 1.0)));;;; => \"Outlook good\";;;; => 0.3187===Other types===Other data types in Common Lisp include:*''Pathnames'' represent files and directories in the filesystem.", "The Common Lisp pathname facility is more general than most operating systems' file naming conventions, making Lisp programs' access to files broadly portable across diverse systems.", "*Input and output ''streams'' represent sources and sinks of binary or textual data, such as the terminal or open files.", "*Common Lisp has a built-in pseudo-random number generator (PRNG).", "''Random state'' objects represent reusable sources of pseudo-random numbers, allowing the user to seed the PRNG or cause it to replay a sequence.", "*''Conditions'' are a type used to represent errors, exceptions, and other \"interesting\" events to which a program may respond.", "*''Classes'' are first-class objects, and are themselves instances of classes called metaobject classes (metaclasses for short).", "*''Readtables'' are a type of object which control how Common Lisp's reader parses the text of source code.", "By controlling which readtable is in use when code is read in, the programmer can change or extend the language's syntax." ], [ "Scope", "Like programs in many other programming languages, Common Lisp programs make use of names to refer to variables, functions, and many other kinds of entities.", "Named references are subject to scope.The association between a name and the entity which the name refers to is called a binding.Scope refers to the set of circumstances in which a name is determined to have a particular binding.===Determiners of scope===The circumstances which determine scope in Common Lisp include:* the location of a reference within an expression.", "If it's the leftmost position of a compound, it refers to a special operator or a macro or function binding, otherwise to a variable binding or something else.", "* the kind of expression in which the reference takes place.", "For instance, (go x) means transfer control to label x, whereas (print x) refers to the variable x.", "Both scopes of x can be active in the same region of program text, since tagbody labels are in a separate namespace from variable names.", "A special form or macro form has complete control over the meanings of all symbols in its syntax.", "For instance, in (defclass x (a b) ()), a class definition, the (a b) is a list of base classes, so these names are looked up in the space of class names, and x isn't a reference to an existing binding, but the name of a new class being derived from a and b.", "These facts emerge purely from the semantics of defclass.", "The only generic fact about this expression is that defclass refers to a macro binding; everything else is up to defclass.", "* the location of the reference within the program text.", "For instance, if a reference to variable x is enclosed in a binding construct such as a let which defines a binding for x, then the reference is in the scope created by that binding.", "* for a variable reference, whether or not a variable symbol has been, locally or globally, declared special.", "This determines whether the reference is resolved within a lexical environment, or within a dynamic environment.", "* the specific instance of the environment in which the reference is resolved.", "An environment is a run-time dictionary which maps symbols to bindings.", "Each kind of reference uses its own kind of environment.", "References to lexical variables are resolved in a lexical environment, et cetera.", "More than one environment can be associated with the same reference.", "For instance, thanks to recursion or the use of multiple threads, multiple activations of the same function can exist at the same time.", "These activations share the same program text, but each has its own lexical environment instance.To understand what a symbol refers to, the Common Lisp programmer must know what kind of reference is being expressed, what kind of scope it uses if it is a variable reference (dynamic versus lexical scope), and also the run-time situation: in what environment is the reference resolved, where was the binding introduced into the environment, et cetera.===Kinds of environment=======Global====Some environments in Lisp are globally pervasive.", "For instance, if a new type is defined, it is known everywhere thereafter.", "References to that type look it up in this global environment.====Dynamic====One type of environment in Common Lisp is the dynamic environment.", "Bindings established in this environment have dynamic extent, which means that a binding is established at the start of the execution of some construct, such as a let block, and disappears when that construct finishes executing: its lifetime is tied to the dynamic activation and deactivation of a block.", "However, a dynamic binding is not just visible within that block; it is also visible to all functions invoked from that block.", "This type of visibility is known as indefinite scope.", "Bindings which exhibit dynamic extent (lifetime tied to the activation and deactivation of a block) and indefinite scope (visible to all functions which are called from that block) are said to have dynamic scope.Common Lisp has support for dynamically scoped variables, which are also called special variables.", "Certain other kinds of bindings are necessarily dynamically scoped also, such as restarts and catch tags.", "Function bindings cannot be dynamically scoped using flet (which only provides lexically scoped function bindings), but function objects (a first-level object in Common Lisp) can be assigned to dynamically scoped variables, bound using let in dynamic scope, then called using funcall or APPLY.Dynamic scope is extremely useful because it adds referential clarity and discipline to global variables.", "Global variables are frowned upon in computer science as potential sources of error, because they can give rise to ad-hoc, covert channels of communication among modules that lead to unwanted, surprising interactions.In Common Lisp, a special variable which has only a top-level binding behaves just like a global variable in other programming languages.", "A new value can be stored into it, and that value simply replaces what is in the top-level binding.", "Careless replacement of the value of a global variable is at the heart of bugs caused by the use of global variables.", "However, another way to work with a special variable is to give it a new, local binding within an expression.", "This is sometimes referred to as \"rebinding\" the variable.", "Binding a dynamically scoped variable temporarily creates a new memory location for that variable, and associates the name with that location.", "While that binding is in effect, all references to that variable refer to the new binding; the previous binding is hidden.", "When execution of the binding expression terminates, the temporary memory location is gone, and the old binding is revealed, with the original value intact.", "Of course, multiple dynamic bindings for the same variable can be nested.In Common Lisp implementations which support multithreading, dynamic scopes are specific to each thread of execution.", "Thus special variables serve as an abstraction for thread local storage.", "If one thread rebinds a special variable, this rebinding has no effect on that variable in other threads.", "The value stored in a binding can only be retrieved by the thread which created that binding.", "If each thread binds some special variable *x*, then *x* behaves like thread-local storage.", "Among threads which do not rebind *x*, it behaves like an ordinary global: all of these threads refer to the same top-level binding of *x*.Dynamic variables can be used to extend the execution context with additional context information which is implicitly passed from function to function without having to appear as an extra function parameter.", "This is especially useful when the control transfer has to pass through layers of unrelated code, which simply cannot be extended with extra parameters to pass the additional data.", "A situation like this usually calls for a global variable.", "That global variable must be saved and restored, so that the scheme doesn't break under recursion: dynamic variable rebinding takes care of this.", "And that variable must be made thread-local (or else a big mutex must be used) so the scheme doesn't break under threads: dynamic scope implementations can take care of this also.In the Common Lisp library, there are many standard special variables.", "For instance, all standard I/O streams are stored in the top-level bindings of well-known special variables.", "The standard output stream is stored in *standard-output*.Suppose a function foo writes to standard output: (defun foo () (format t \"Hello, world\"))To capture its output in a character string, *standard-output* can be bound to a string stream and called: (with-output-to-string (*standard-output*) (foo)) -> \"Hello, world\" ; gathered output returned as a string====Lexical====Common Lisp supports lexical environments.", "Formally, the bindings in a lexical environment have lexical scope and may have either an indefinite extent or dynamic extent, depending on the type of namespace.", "Lexical scope means that visibility is physically restricted to the block in which the binding is established.", "References which are not textually (i.e.", "lexically) embedded in that block simply do not see that binding.The tags in a TAGBODY have lexical scope.", "The expression (GO X) is erroneous if it is not embedded in a TAGBODY which contains a label X.", "However, the label bindings disappear when the TAGBODY terminates its execution, because they have dynamic extent.", "If that block of code is re-entered by the invocation of a lexical closure, it is invalid for the body of that closure to try to transfer control to a tag via GO: (defvar *stashed*) ;; will hold a function (tagbody (setf *stashed* (lambda () (go some-label))) (go end-label) ;; skip the (print \"Hello\") some-label (print \"Hello\") end-label) -> NILWhen the TAGBODY is executed, it first evaluates the setf form which stores a function in the special variable *stashed*.", "Then the (go end-label) transfers control to end-label, skipping the code (print \"Hello\").", "Since end-label is at the end of the tagbody, the tagbody terminates, yielding NIL.", "Suppose that the previously remembered function is now called: (funcall *stashed*) ;; Error!This situation is erroneous.", "One implementation's response is an error condition containing the message, \"GO: tagbody for tag SOME-LABEL has already been left\".", "The function tried to evaluate (go some-label), which is lexically embedded in the tagbody, and resolves to the label.", "However, the tagbody isn't executing (its extent has ended), and so the control transfer cannot take place.Local function bindings in Lisp have lexical scope, and variable bindings also have lexical scope by default.", "By contrast with GO labels, both of these have indefinite extent.", "When a lexical function or variable binding is established, that binding continues to exist for as long as references to it are possible, even after the construct which established that binding has terminated.", "References to lexical variables and functions after the termination of their establishing construct are possible thanks to lexical closures.Lexical binding is the default binding mode for Common Lisp variables.", "For an individual symbol, it can be switched to dynamic scope, either by a local declaration, by a global declaration.", "The latter may occur implicitly through the use of a construct like DEFVAR or DEFPARAMETER.", "It is an important convention in Common Lisp programming that special (i.e.", "dynamically scoped) variables have names which begin and end with an asterisk sigil * in what is called the \"earmuff convention\".", "If adhered to, this convention effectively creates a separate namespace for special variables, so that variables intended to be lexical are not accidentally made special.Lexical scope is useful for several reasons.Firstly, references to variables and functions can be compiled to efficient machine code, because the run-time environment structure is relatively simple.", "In many cases it can be optimized to stack storage, so opening and closing lexical scopes has minimal overhead.", "Even in cases where full closures must be generated, access to the closure's environment is still efficient; typically each variable becomes an offset into a vector of bindings, and so a variable reference becomes a simple load or store instruction with a base-plus-offset addressing mode.Secondly, lexical scope (combined with indefinite extent) gives rise to the lexical closure, which in turn creates a whole paradigm of programming centered around the use of functions being first-class objects, which is at the root of functional programming.Thirdly, perhaps most importantly, even if lexical closures are not exploited, the use of lexical scope isolates program modules from unwanted interactions.", "Due to their restricted visibility, lexical variables are private.", "If one module A binds a lexical variable X, and calls another module B, references to X in B will not accidentally resolve to the X bound in A.", "B simply has no access to X.", "For situations in which disciplined interactions through a variable are desirable, Common Lisp provides special variables.", "Special variables allow for a module A to set up a binding for a variable X which is visible to another module B, called from A.", "Being able to do this is an advantage, and being able to prevent it from happening is also an advantage; consequently, Common Lisp supports both lexical and dynamic scope." ], [ "Macros", "A ''macro'' in Lisp superficially resembles a function in usage.", "However, rather than representing an expression which is evaluated, it represents a transformation of the program source code.", "The macro gets the source it surrounds as arguments, binds them to its parameters and computes a new source form.", "This new form can also use a macro.", "The macro expansion is repeated until the new source form does not use a macro.", "The final computed form is the source code executed at runtime.Typical uses of macros in Lisp:* new control structures (example: looping constructs, branching constructs)* scoping and binding constructs* simplified syntax for complex and repeated source code* top-level defining forms with compile-time side-effects* data-driven programming* embedded domain specific languages (examples: SQL, HTML, Prolog)* implicit finalization formsVarious standard Common Lisp features also need to be implemented as macros, such as:* the standard setf abstraction, to allow custom compile-time expansions of assignment/access operators* with-accessors, with-slots, with-open-file and other similar WITH macros* Depending on implementation, if or cond is a macro built on the other, the special operator; when and unless consist of macros* The powerful loop domain-specific languageMacros are defined by the ''defmacro'' macro.", "The special operator ''macrolet'' allows the definition of local (lexically scoped) macros.", "It is also possible to define macros for symbols using ''define-symbol-macro'' and ''symbol-macrolet''.Paul Graham's book On Lisp describes the use of macros in Common Lisp in detail.", "Doug Hoyte's book Let Over Lambda extends the discussion on macros, claiming \"Macros are the single greatest advantage that lisp has as a programming language and the single greatest advantage of any programming language.\"", "Hoyte provides several examples of iterative development of macros.===Example using a macro to define a new control structure===Macros allow Lisp programmers to create new syntactic forms in the language.", "One typical use is to create new control structures.", "The example macro provides an until looping construct.", "The syntax is:(until test form*)The macro definition for ''until'':(defmacro until (test &body body) (let ((start-tag (gensym \"START\")) (end-tag (gensym \"END\"))) `(tagbody ,start-tag (when ,test (go ,end-tag)) (progn ,@body) (go ,start-tag) ,end-tag)))''tagbody'' is a primitive Common Lisp special operator which provides the ability to name tags and use the ''go'' form to jump to those tags.", "The backquote ''`'' provides a notation that provides code templates, where the value of forms preceded with a comma are filled in.", "Forms preceded with comma and at-sign are ''spliced'' in.", "The tagbody form tests the end condition.", "If the condition is true, it jumps to the end tag.", "Otherwise, the provided body code is executed and then it jumps to the start tag.An example of using the above ''until'' macro:(until (= (random 10) 0) (write-line \"Hello\"))The code can be expanded using the function ''macroexpand-1''.", "The expansion for the above example looks like this:(TAGBODY #:START1136 (WHEN (ZEROP (RANDOM 10)) (GO #:END1137)) (PROGN (WRITE-LINE \"hello\")) (GO #:START1136) #:END1137)During macro expansion the value of the variable ''test'' is ''(= (random 10) 0)'' and the value of the variable ''body'' is ''((write-line \"Hello\"))''.", "The body is a list of forms.Symbols are usually automatically upcased.", "The expansion uses the TAGBODY with two labels.", "The symbols for these labels are computed by GENSYM and are not interned in any package.", "Two ''go'' forms use these tags to jump to.", "Since ''tagbody'' is a primitive operator in Common Lisp (and not a macro), it will not be expanded into something else.", "The expanded form uses the ''when'' macro, which also will be expanded.", "Fully expanding a source form is called ''code walking''.In the fully expanded (''walked'') form, the ''when'' form is replaced by the primitive ''if'':(TAGBODY #:START1136 (IF (ZEROP (RANDOM 10)) (PROGN (GO #:END1137)) NIL) (PROGN (WRITE-LINE \"hello\")) (GO #:START1136)) #:END1137)All macros must be expanded before the source code containing them can be evaluated or compiled normally.", "Macros can be considered functions that accept and return S-expressions – similar to abstract syntax trees, but not limited to those.", "These functions are invoked before the evaluator or compiler to produce the final source code.", "Macros are written in normal Common Lisp, and may use any Common Lisp (or third-party) operator available.===Variable capture and shadowing===Common Lisp macros are capable of what is commonly called ''variable capture'', where symbols in the macro-expansion body coincide with those in the calling context, allowing the programmer to create macros wherein various symbols have special meaning.", "The term ''variable capture'' is somewhat misleading, because all namespaces are vulnerable to unwanted capture, including the operator and function namespace, the tagbody label namespace, catch tag, condition handler and restart namespaces.", "''Variable capture'' can introduce software defects.", "This happens in one of the following two ways:* In the first way, a macro expansion can inadvertently make a symbolic reference which the macro writer assumed will resolve in a global namespace, but the code where the macro is expanded happens to provide a local, shadowing definition which steals that reference.", "Let this be referred to as type 1 capture.", "* The second way, type 2 capture, is just the opposite: some of the arguments of the macro are pieces of code supplied by the macro caller, and those pieces of code are written such that they make references to surrounding bindings.", "However, the macro inserts these pieces of code into an expansion which defines its own bindings that accidentally captures some of these references.The Scheme dialect of Lisp provides a macro-writing system which provides the referential transparency that eliminates both types of capture problem.", "This type of macro system is sometimes called \"hygienic\", in particular by its proponents (who regard macro systems which do not automatically solve this problem as unhygienic).", "In Common Lisp, macro hygiene is ensured one of two different ways.One approach is to use gensyms: guaranteed-unique symbols which can be used in a macro-expansion without threat of capture.", "The use of gensyms in a macro definition is a manual chore, but macros can be written which simplify the instantiation and use of gensyms.", "Gensyms solve type 2 capture easily, but they are not applicable to type 1 capture in the same way, because the macro expansion cannot rename the interfering symbols in the surrounding code which capture its references.", "Gensyms could be used to provide stable aliases for the global symbols which the macro expansion needs.", "The macro expansion would use these secret aliases rather than the well-known names, so redefinition of the well-known names would have no ill effect on the macro.Another approach is to use packages.", "A macro defined in its own package can simply use internal symbols in that package in its expansion.", "The use of packages deals with type 1 and type 2 capture.However, packages don't solve the type 1 capture of references to standard Common Lisp functions and operators.", "The reason is that the use of packages to solve capture problems revolves around the use of private symbols (symbols in one package, which are not imported into, or otherwise made visible in other packages).", "Whereas the Common Lisp library symbols are external, and frequently imported into or made visible in user-defined packages.The following is an example of unwanted capture in the operator namespace, occurring in the expansion of a macro: ;; expansion of UNTIL makes liberal use of DO (defmacro until (expression &body body) `(do () (,expression) ,@body)) ;; macrolet establishes lexical operator binding for DO (macrolet ((do (...) ... something else ...)) (until (= (random 10) 0) (write-line \"Hello\")))The until macro will expand into a form which calls do which is intended to refer to the standard Common Lisp macro do.", "However, in this context, do may have a completely different meaning, so until may not work properly.Common Lisp solves the problem of the shadowing of standard operators and functions by forbidding their redefinition.", "Because it redefines the standard operator do, the preceding is actually a fragment of non-conforming Common Lisp, which allows implementations to diagnose and reject it." ], [ "Condition system", "The ''condition system'' is responsible for exception handling in Common Lisp.", "It provides ''conditions'', ''handler''s and ''restart''s.", "''Condition''s are objects describing an exceptional situation (for example an error).", "If a ''condition'' is signaled, the Common Lisp system searches for a ''handler'' for this condition type and calls the handler.", "The ''handler'' can now search for restarts and use one of these restarts to automatically repair the current problem, using information such as the condition type and any relevant information provided as part of the condition object, and call the appropriate restart function.These restarts, if unhandled by code, can be presented to users (as part of a user interface, that of a debugger for example), so that the user can select and invoke one of the available restarts.", "Since the condition handler is called in the context of the error (without unwinding the stack), full error recovery is possible in many cases, where other exception handling systems would have already terminated the current routine.", "The debugger itself can also be customized or replaced using the *debugger-hook* dynamic variable.", "Code found within ''unwind-protect'' forms such as finalizers will also be executed as appropriate despite the exception.In the following example (using Symbolics Genera) the user tries to open a file in a Lisp function ''test'' called from the Read-Eval-Print-LOOP (REPL), when the file does not exist.", "The Lisp system presents four restarts.", "The user selects the ''Retry OPEN using a different pathname'' restart and enters a different pathname (lispm-init.lisp instead of lispm-int.lisp).", "The user code does not contain any error handling code.", "The whole error handling and restart code is provided by the Lisp system, which can handle and repair the error without terminating the user code.Command: (test \">zippy>lispm-int.lisp\")Error: The file was not found.", "For lispm:>zippy>lispm-int.lisp.newestLMFS:OPEN-LOCAL-LMFS-1 Arg 0: #P\"lispm:>zippy>lispm-int.lisp.newest\"s-A, : Retry OPEN of lispm:>zippy>lispm-int.lisp.newests-B: Retry OPEN using a different pathnames-C, : Return to Lisp Top Level in a TELNET servers-D: Restart process TELNET terminal-> Retry OPEN using a different pathnameUse what pathname instead default lispm:>zippy>lispm-int.lisp.newest: lispm:>zippy>lispm-init.lisp.newest...the program continues" ], [ "Common Lisp Object System (CLOS)", "Common Lisp includes a toolkit for object-oriented programming, the Common Lisp Object System or CLOS.", "Peter Norvig explains how many Design Patterns are simpler to implement in a dynamic language with the features of CLOS (Multiple Inheritance, Mixins, Multimethods, Metaclasses, Method combinations, etc.", ").Several extensions to Common Lisp for object-oriented programming have been proposed to be included into the ANSI Common Lisp standard, but eventually CLOS was adopted as the standard object-system for Common Lisp.", "CLOS is a dynamic object system with multiple dispatch and multiple inheritance, and differs radically from the OOP facilities found in static languages such as C++ or Java.", "As a dynamic object system, CLOS allows changes at runtime to generic functions and classes.", "Methods can be added and removed, classes can be added and redefined, objects can be updated for class changes and the class of objects can be changed.CLOS has been integrated into ANSI Common Lisp.", "Generic functions can be used like normal functions and are a first-class data type.", "Every CLOS class is integrated into the Common Lisp type system.", "Many Common Lisp types have a corresponding class.", "There is more potential use of CLOS for Common Lisp.", "The specification does not say whether conditions are implemented with CLOS.", "Pathnames and streams could be implemented with CLOS.", "These further usage possibilities of CLOS for ANSI Common Lisp are not part of the standard.", "Actual Common Lisp implementations use CLOS for pathnames, streams, input–output, conditions, the implementation of CLOS itself and more." ], [ "Compiler and interpreter", "A Lisp interpreter directly executes Lisp source code provided as Lisp objects (lists, symbols, numbers, ...) read from s-expressions.", "A Lisp compiler generates bytecode or machine code from Lisp source code.", "Common Lisp allows both individual Lisp functions to be compiled in memory and the compilation of whole files to externally stored compiled code (''fasl'' files).Several implementations of earlier Lisp dialects provided both an interpreter and a compiler.", "Unfortunately often the semantics were different.", "These earlier Lisps implemented lexical scoping in the compiler and dynamic scoping in the interpreter.", "Common Lisp requires that both the interpreter and compiler use lexical scoping by default.", "The Common Lisp standard describes both the semantics of the interpreter and a compiler.", "The compiler can be called using the function ''compile'' for individual functions and using the function ''compile-file'' for files.", "Common Lisp allows type declarations and provides ways to influence the compiler code generation policy.", "For the latter various optimization qualities can be given values between 0 (not important) and 3 (most important): ''speed'', ''space'', ''safety'', ''debug'' and ''compilation-speed''.There is also a function to evaluate Lisp code: eval.", "eval takes code as pre-parsed s-expressions and not, like in some other languages, as text strings.", "This way code can be constructed with the usual Lisp functions for constructing lists and symbols and then this code can be evaluated with the function eval.", "Several Common Lisp implementations (like Clozure CL and SBCL) are implementing eval using their compiler.", "This way code is compiled, even though it is evaluated using the function eval.The file compiler is invoked using the function ''compile-file''.", "The generated file with compiled code is called a ''fasl'' (from ''fast load'') file.", "These ''fasl'' files and also source code files can be loaded with the function ''load'' into a running Common Lisp system.", "Depending on the implementation, the file compiler generates byte-code (for example for the Java Virtual Machine), C language code (which then is compiled with a C compiler) or, directly, native code.Common Lisp implementations can be used interactively, even though the code gets fully compiled.", "The idea of an Interpreted language thus does not apply for interactive Common Lisp.The language makes a distinction between read-time, compile-time, load-time, and run-time, and allows user code to also make this distinction to perform the wanted type of processing at the wanted step.Some special operators are provided to especially suit interactive development; for instance, defvar will only assign a value to its provided variable if it wasn't already bound, while defparameter will always perform the assignment.", "This distinction is useful when interactively evaluating, compiling and loading code in a live image.Some features are also provided to help writing compilers and interpreters.", "Symbols consist of first-level objects and are directly manipulable by user code.", "The progv special operator allows to create lexical bindings programmatically, while packages are also manipulable.", "The Lisp compiler is available at runtime to compile files or individual functions.", "These make it easy to use Lisp as an intermediate compiler or interpreter for another language." ], [ "Code examples", "===Birthday paradox===The following program calculates the smallest number of people in a room for whom the probability of unique birthdays is less than 50% (the birthday paradox, where for 1 person the probability is obviously 100%, for 2 it is 364/365, etc.).", "The answer is 23.In Common Lisp, by convention, constants are enclosed with + characters.", "(defconstant +year-size+ 365)(defun birthday-paradox (probability number-of-people) (let ((new-probability (* (/ (- +year-size+ number-of-people) +year-size+) probability))) (if (Calling the example function using the REPL (Read Eval Print Loop):CL-USER > (birthday-paradox 1.0 1)23===Sorting a list of person objects===We define a class person and a method for displaying the name and age of a person.Next we define a group of persons as a list of person objects.Then we iterate over the sorted list.", "(defclass person () ((name :initarg :name :accessor person-name) (age :initarg :age :accessor person-age)) (:documentation \"The class PERSON with slots NAME and AGE.", "\"))(defmethod display ((object person) stream) \"Displaying a PERSON object to an output stream.\"", "(with-slots (name age) object (format stream \"~a (~a)\" name age)))(defparameter *group* (list (make-instance 'person :name \"Bob\" :age 33) (make-instance 'person :name \"Chris\" :age 16) (make-instance 'person :name \"Ash\" :age 23)) \"A list of PERSON objects.", "\")(dolist (person (sort (copy-list *group*) #'> :key #'person-age)) (display person *standard-output*) (terpri))It prints the three names with descending age.Bob (33)Ash (23)Chris (16)===Exponentiating by squaring===Use of the LOOP macro is demonstrated:(defun power (x n) (loop with result = 1 while (plusp n) when (oddp n) do (setf result (* result x)) do (setf x (* x x) n (truncate n 2)) finally (return result)))Example use:CL-USER > (power 2 200)1606938044258990275541962092341162602522202993782792835301376Compare with the built in exponentiation:CL-USER > (= (expt 2 200) (power 2 200))T===Find the list of available shells===WITH-OPEN-FILE is a macro that opens a file and provides a stream.", "When the form is returning, the file is automatically closed.", "FUNCALL calls a function object.", "The LOOP collects all lines that match the predicate.", "(defun list-matching-lines (file predicate) \"Returns a list of lines in file, for which the predicate applied to the line returns T.\" (with-open-file (stream file) (loop for line = (read-line stream nil nil) while line when (funcall predicate line) collect it)))The function AVAILABLE-SHELLS calls the above function LIST-MATCHING-LINES with a pathname and an anonymous function as the predicate.", "The predicate returns the pathname of a shell or NIL (if the string is not the filename of a shell).", "(defun available-shells (&optional (file #p\"/etc/shells\")) (list-matching-lines file (lambda (line) (and (plusp (length line)) (char= (char line 0) #\\/) (pathname (string-right-trim '(#\\space #\\tab) line))))))Example results (on Mac OS X 10.6):CL-USER > (available-shells)(#P\"/bin/bash\" #P\"/bin/csh\" #P\"/bin/ksh\" #P\"/bin/sh\" #P\"/bin/tcsh\" #P\"/bin/zsh\")" ], [ "Comparison with other Lisps", "Common Lisp is most frequently compared with, and contrasted to, Scheme—if only because they are the two most popular Lisp dialects.", "Scheme predates CL, and comes not only from the same Lisp tradition but from some of the same engineers—Guy Steele, with whom Gerald Jay Sussman designed Scheme, chaired the standards committee for Common Lisp.Common Lisp is a general-purpose programming language, in contrast to Lisp variants such as Emacs Lisp and AutoLISP which are extension languages embedded in particular products (GNU Emacs and AutoCAD, respectively).", "Unlike many earlier Lisps, Common Lisp (like Scheme) uses lexical variable scope by default for both interpreted and compiled code.Most of the Lisp systems whose designs contributed to Common Lisp—such as ZetaLisp and Franz Lisp—used dynamically scoped variables in their interpreters and lexically scoped variables in their compilers.", "Scheme introduced the sole use of lexically scoped variables to Lisp; an inspiration from ALGOL 68.CL supports dynamically scoped variables as well, but they must be explicitly declared as \"special\".", "There are no differences in scoping between ANSI CL interpreters and compilers.Common Lisp is sometimes termed a ''Lisp-2'' and Scheme a ''Lisp-1'', referring to CL's use of separate namespaces for functions and variables.", "(In fact, CL has ''many'' namespaces, such as those for go tags, block names, and loop keywords).", "There is a long-standing controversy between CL and Scheme advocates over the tradeoffs involved in multiple namespaces.", "In Scheme, it is (broadly) necessary to avoid giving variables names which clash with functions; Scheme functions frequently have arguments named lis, lst, or lyst so as not to conflict with the system function list.", "However, in CL it is necessary to explicitly refer to the function namespace when passing a function as an argument—which is also a common occurrence, as in the sort example above.CL also differs from Scheme in its handling of boolean values.", "Scheme uses the special values #t and #f to represent truth and falsity.", "CL follows the older Lisp convention of using the symbols T and NIL, with NIL standing also for the empty list.", "In CL, ''any'' non-NIL value is treated as true by conditionals, such as if, whereas in Scheme all non-#f values are treated as true.", "These conventions allow some operators in both languages to serve both as predicates (answering a boolean-valued question) and as returning a useful value for further computation, but in Scheme the value '() which is equivalent to NIL in Common Lisp evaluates to true in a boolean expression.Lastly, the Scheme standards documents require tail-call optimization, which the CL standard does not.", "Most CL implementations do offer tail-call optimization, although often only when the programmer uses an optimization directive.", "Nonetheless, common CL coding style does not favor the ubiquitous use of recursion that Scheme style prefers—what a Scheme programmer would express with tail recursion, a CL user would usually express with an iterative expression in do, dolist, loop, or (more recently) with the iterate package." ], [ "Implementations", "See the Category Common Lisp implementations.Common Lisp is defined by a specification (like Ada and C) rather than by one implementation (like Perl).", "There are many implementations, and the standard details areas in which they may validly differ.In addition, implementations tend to come with extensions, which provide functionality not covered in the standard:* Interactive Top-Level (REPL)* Garbage Collection* Debugger, Stepper and Inspector* Weak data structures (hash tables)* Extensible sequences* Extensible LOOP* Environment access* CLOS Meta-object Protocol* CLOS based extensible streams* CLOS based Condition System* Network streams* Persistent CLOS* Unicode support* Foreign-Language Interface (often to C)* Operating System interface* Java Interface* Threads and Multiprocessing* Application delivery (applications, dynamic libraries)* Saving of imagesFree and open-source software libraries have been created to support extensions to Common Lisp in a portable way, and are most notably found in the repositories of the Common-Lisp.net and CLOCC (Common Lisp Open Code Collection) projects.Common Lisp implementations may use any mix of native code compilation, byte code compilation or interpretation.", "Common Lisp has been designed to support incremental compilers, file compilers and block compilers.", "Standard declarations to optimize compilation (such as function inlining or type specialization) are proposed in the language specification.", "Most Common Lisp implementations compile source code to native machine code.", "Some implementations can create (optimized) stand-alone applications.", "Others compile to interpreted bytecode, which is less efficient than native code, but eases binary-code portability.", "Some compilers compile Common Lisp code to C code.", "The misconception that Lisp is a purely interpreted language is most likely because Lisp environments provide an interactive prompt and that code is compiled one-by-one, in an incremental way.", "With Common Lisp incremental compilation is widely used.Some Unix-based implementations (CLISP, SBCL) can be used as a scripting language; that is, invoked by the system transparently in the way that a Perl or Unix shell interpreter is.===List of implementations=======Commercial implementations====; Allegro Common Lisp: for Microsoft Windows, FreeBSD, Linux, Apple macOS and various UNIX variants.", "Allegro CL provides an Integrated Development Environment (IDE) (for Windows and Linux) and extensive capabilities for application delivery.", "; Liquid Common Lisp: formerly called Lucid Common Lisp.", "Only maintenance, no new releases.", "; LispWorks: for Microsoft Windows, FreeBSD, Linux, Apple macOS, iOS, Android and various UNIX variants.", "LispWorks provides an Integrated Development Environment (IDE) (available for most platforms, but not for iOS and Android) and extensive capabilities for application delivery.", "; mocl: for iOS, Android and macOS.", "; Open Genera: for DEC Alpha.", "; Scieneer Common Lisp: which is designed for high-performance scientific computing.====Freely redistributable implementations====; Armed Bear Common Lisp (ABCL): A CL implementation that runs on the Java Virtual Machine.", "It includes a compiler to Java byte code, and allows access to Java libraries from CL.", "It was formerly just a component of the Armed Bear J Editor.", "; Clasp: A LLVM based implementation that seamlessly interoperates with C++ libraries.", "Runs on several Unix and Unix-like systems (including macOS).", "; CLISP: A bytecode-compiling implementation, portable and runs on several Unix and Unix-like systems (including macOS), as well as Microsoft Windows and several other systems.", "; Clozure CL (CCL): Originally a free and open-source fork of Macintosh Common Lisp.", "As that history implies, CCL was written for the Macintosh, but Clozure CL now runs on macOS, FreeBSD, Linux, Solaris and Windows.", "32 and 64 bit x86 ports are supported on each platform.", "Additionally there are Power PC ports for Mac OS and Linux.", "CCL was previously known as OpenMCL, but that name is no longer used, to avoid confusion with the open source version of Macintosh Common Lisp.", "; CMUCL: Originally from Carnegie Mellon University, now maintained as free and open-source software by a group of volunteers.", "CMUCL uses a fast native-code compiler.", "It is available on Linux and BSD for Intel x86; Linux for Alpha; macOS for Intel x86 and PowerPC; and Solaris, IRIX, and HP-UX on their native platforms.", "; Corman Common Lisp: for Microsoft Windows.", "In January 2015 Corman Lisp has been published under MIT license.", "; Embeddable Common Lisp (ECL): ECL includes a bytecode interpreter and compiler.", "It can also compile Lisp code to machine code via a C compiler.", "ECL then compiles Lisp code to C, compiles the C code with a C compiler and can then load the resulting machine code.", "It is also possible to embed ECL in C programs, and C code into Common Lisp programs.", "; GNU Common Lisp (GCL): The GNU Project's Lisp compiler.", "Not yet fully ANSI-compliant, GCL is however the implementation of choice for several large projects including the mathematical tools Maxima, AXIOM and (historically) ACL2.GCL runs on Linux under eleven different architectures, and also under Windows, Solaris, and FreeBSD.", "; Macintosh Common Lisp (MCL): Version 5.2 for Apple Macintosh computers with a PowerPC processor running Mac OS X is open source.", "RMCL (based on MCL 5.2) runs on Intel-based Apple Macintosh computers using the Rosetta binary translator from Apple.", "; ManKai Common Lisp (MKCL): A branch of ECL.", "MKCL emphasises reliability, stability and overall code quality through a heavily reworked, natively multi-threaded, runtime system.", "On Linux, MKCL features a fully POSIX compliant runtime system.", "; Movitz: Implements a Lisp environment for x86 computers without relying on any underlying OS.", "; Poplog: Poplog implements a version of CL, with POP-11, and optionally Prolog, and Standard ML (SML), allowing mixed language programming.", "For all, the implementation language is POP-11, which is compiled incrementally.", "It also has an integrated Emacs-like editor that communicates with the compiler.", "; Steel Bank Common Lisp (SBCL): A branch from CMUCL.", "\"Broadly speaking, SBCL is distinguished from CMU CL by a greater emphasis on maintainability.\"", "SBCL runs on the platforms CMUCL does, except HP/UX; in addition, it runs on Linux for AMD64, PowerPC, SPARC, MIPS, Windows x86 and has experimental support for running on Windows AMD64.SBCL does not use an interpreter by default; all expressions are compiled to native code unless the user switches the interpreter on.", "The SBCL compiler generates fast native code according to a previous version of The Computer Language Benchmarks Game.", "; Ufasoft Common Lisp: port of CLISP for windows platform with core written in C++.====Other implementations====; Austin Kyoto Common Lisp: an evolution of Kyoto Common Lisp by Bill Schelter; Butterfly Common Lisp: an implementation written in Scheme for the BBN Butterfly multi-processor computer; CLICC: a Common Lisp to C compiler; CLOE: Common Lisp for PCs by Symbolics; Codemist Common Lisp: used for the commercial version of the computer algebra system Axiom; ExperCommon Lisp: an early implementation for the Apple Macintosh by ExperTelligence; Golden Common Lisp: an implementation for the PC by GoldHill Inc.; Ibuki Common Lisp: a commercialized version of Kyoto Common Lisp; Kyoto Common Lisp: the first Common Lisp compiler that used C as a target language.", "GCL, ECL and MKCL originate from this Common Lisp implementation.", "; L: a small version of Common Lisp for embedded systems developed by IS Robotics, now iRobot; Lisp Machines (from Symbolics, TI and Xerox): provided implementations of Common Lisp in addition to their native Lisp dialect (Lisp Machine Lisp or Interlisp).", "CLOS was also available.", "Symbolics provides an enhanced version Common Lisp.", "; Procyon Common Lisp: an implementation for Windows and Mac OS, used by Franz for their Windows port of Allegro CL; Star Sapphire Common LISP: an implementation for the PC; SubL: a variant of Common Lisp used for the implementation of the Cyc knowledge-based system; Top Level Common Lisp: an early implementation for concurrent execution; WCL: a shared library implementation ; VAX Common Lisp: Digital Equipment Corporation's implementation that ran on VAX systems running VMS or ULTRIX; XLISP: an implementation written by David Betz" ], [ "Applications", "Common Lisp is used to develop research applications (often in Artificial Intelligence), for rapid development of prototypes or for deployed applications.Common Lisp is used in many commercial applications, including the Yahoo!", "Store web-commerce site, which originally involved Paul Graham and was later rewritten in C++ and Perl.", "Other notable examples include:* ACT-R, a cognitive architecture used in a large number of research projects.", "* Authorizer's Assistant, a large rule-based system used by American Express, analyzing credit requests.", "* Cyc, a long running project to create a knowledge-based system that provides a huge amount of common sense knowledge.", "* Gensym G2, a real-time expert system and business rules engine* Genworks GDL, based on the open-source Gendl kernel.", "* The development environment for the ''Jak and Daxter'' video game series, developed by Naughty Dog.", "* ITA Software's low fare search engine, used by travel websites such as Orbitz and Kayak.com and airlines such as American Airlines, Continental Airlines and US Airways.", "* Mirai, a 3D graphics suite.", "It was used to animate the face of Gollum in the movie ''Lord of the Rings: The Two Towers''.", "* Opusmodus is a music composition system based on Common Lisp, used in Computer assisted composition.", "* Prototype Verification System (PVS), a mechanized environment for formal specification and verification.", "* PWGL is a sophisticated visual programming environment based on Common Lisp, used in Computer assisted composition and sound synthesis.", "* Piano, a complete aircraft analysis suite, written in Common Lisp, used by companies like Boeing, Airbus, and Northrop Grumman.", "* Grammarly, an English-language writing-enhancement platform, has its core grammar engine written in Common Lisp.", "* The Dynamic Analysis and Replanning Tool (DART), which is said to alone have paid back during the years from 1991 to 1995 for all thirty years of DARPA investments in AI research.", "* NASA's Jet Propulsion Lab's \"Deep Space 1\", an award-winning Common Lisp program for autopiloting the Deep Space One spaceship.", "* SigLab, a Common Lisp platform for signal processing used in missile defense, built by Raytheon.", "* NASA's Mars Pathfinder Mission Planning System.", "* SPIKE, a scheduling system for Earth or space based observatories and satellites, notably the Hubble Space Telescope, written in Common Lisp.", "* Common Lisp has been used for prototyping the garbage collector of Microsoft's .NET Common Language Runtime.", "* The original version of Reddit, though the developers later switched to Python due to the lack of libraries for Common Lisp, according to an official blog post by Reddit co-founder Steve Huffman.There also exist open-source applications written in Common Lisp, such as:* ACL2, a full-featured automated theorem prover for an applicative variant of Common Lisp.", "* Axiom, a sophisticated computer algebra system.", "* Maxima, a sophisticated computer algebra system, based on Macsyma.", "* OpenMusic, an object-oriented visual programming environment based on Common Lisp, used in computer assisted composition.", "* Pgloader, a data loader for PostgreSQL, which was re-written from Python to Common Lisp.", "* Stumpwm, a tiling, keyboard driven X11 Window Manager written entirely in Common Lisp." ], [ "See also", "*''Common Lisp the Language''*''On Lisp''*''Practical Common Lisp''" ], [ "References" ], [ "Bibliography", "A chronological list of books published (or about to be published) about Common Lisp (the language) or about programming with Common Lisp (especially AI programming).", "* Guy L. Steele: ''Common Lisp the Language, 1st Edition'', Digital Press, 1984, * Rodney Allen Brooks: ''Programming in Common Lisp'', John Wiley and Sons Inc, 1985, * Richard P. Gabriel: ''Performance and Evaluation of Lisp Systems'', The MIT Press, 1985, , PDF* Robert Wilensky: ''Common LISPcraft'', W.W. Norton & Co., 1986, * Eugene Charniak, Christopher K. Riesbeck, Drew V. McDermott, James R. Meehan: ''Artificial Intelligence Programming, 2nd Edition'', Lawrence Erlbaum, 1987, * Wendy L. Milner: ''Common Lisp: A Tutorial'', Prentice Hall, 1987, * Deborah G. Tatar: ''A Programmer's Guide to Common Lisp'', Longman Higher Education, 1987, * Taiichi Yuasa, Masami Hagiya: ''Introduction to Common Lisp'', Elsevier Ltd, 1987, * Christian Queinnec, Jerome Chailloux: ''Lisp Evolution and Standardization'', Ios Pr Inc., 1988, * Taiichi Yuasa, Richard Weyhrauch, Yasuko Kitajima: ''Common Lisp Drill'', Academic Press Inc, 1988, * Wade L. Hennessey: ''Common Lisp'', McGraw-Hill Inc., 1989, * Tony Hasemer, John Dominque: ''Common Lisp Programming for Artificial Intelligence'', Addison-Wesley Educational Publishers Inc, 1989, * Sonya E. Keene: ''Object-Oriented Programming in Common Lisp: A Programmer's Guide to CLOS'', Addison-Wesley, 1989, * David Jay Steele: ''Golden Common Lisp: A Hands-On Approach'', Addison Wesley, 1989, * David S. Touretzky: ''Common Lisp: A Gentle Introduction to Symbolic Computation'', Benjamin-Cummings, 1989, .", "Web/PDF Dover reprint (2013) * Christopher K. Riesbeck, Roger C. Schank: ''Inside Case-Based Reasoning'', Lawrence Erlbaum, 1989, * Patrick Winston, Berthold Horn: ''Lisp, 3rd Edition'', Addison-Wesley, 1989, , Web* Gerard Gazdar, Chris Mellish: ''Natural Language Processing in LISP: An Introduction to Computational Linguistics'', Addison-Wesley Longman Publishing Co., 1990, * Patrick R. Harrison: ''Common Lisp and Artificial Intelligence'', Prentice Hall PTR, 1990, * Timothy Koschmann: ''The Common Lisp Companion'', John Wiley & Sons, 1990, * W. Richard Stark: ''LISP, Lore, and Logic'', Springer Verlag New York Inc., 1990, , PDF* Molly M. Miller, Eric Benson: ''Lisp Style & Design'', Digital Press, 1990, * Guy L. Steele: ''Common Lisp the Language, 2nd Edition'', Digital Press, 1990, , Web* Robin Jones, Clive Maynard, Ian Stewart: ''The Art of Lisp Programming'', Springer Verlag New York Inc., 1990, , PDF* Steven L. Tanimoto: ''The Elements of Artificial Intelligence Using Common Lisp'', Computer Science Press, 1990, * Peter Lee: ''Topics in Advanced Language Implementation'', The MIT Press, 1991, * John H. Riley: ''A Common Lisp Workbook'', Prentice Hall, 1991, * Peter Norvig: ''Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp'', Morgan Kaufmann, 1991, , Web* Gregor Kiczales, Jim des Rivieres, Daniel G. Bobrow: ''The Art of the Metaobject Protocol'', The MIT Press, 1991, * Jo A. Lawless, Molly M. Miller: ''Understanding CLOS: The Common Lisp Object System'', Digital Press, 1991, * Mark Watson: ''Common Lisp Modules: Artificial Intelligence in the Era of Neural Networks and Chaos Theory'', Springer Verlag New York Inc., 1991, , PDF* James L. Noyes: ''Artificial Intelligence with Common Lisp: Fundamentals of Symbolic and Numeric Processing'', Jones & Bartlett Pub, 1992, * Stuart C. Shapiro: ''COMMON LISP: An Interactive Approach'', Computer Science Press, 1992, , Web/PDF* Kenneth D. Forbus, Johan de Kleer: ''Building Problem Solvers'', The MIT Press, 1993, * Andreas Paepcke: ''Object-Oriented Programming: The CLOS Perspective'', The MIT Press, 1993, * Paul Graham: ''On Lisp'', Prentice Hall, 1993, , Web/PDF* Paul Graham: ''ANSI Common Lisp'', Prentice Hall, 1995, * Otto Mayer: ''Programmieren in Common Lisp'', German, Spektrum Akademischer Verlag, 1995, * Stephen Slade: ''Object-Oriented Common Lisp'', Prentice Hall, 1997, * Richard P. Gabriel: ''Patterns of Software: Tales from the Software Community'', Oxford University Press, 1998, , PDF* Taiichi Yuasa, Hiroshi G. Okuno: ''Advanced Lisp Technology'', CRC, 2002, * David B. Lamkins: ''Successful Lisp: How to Understand and Use Common Lisp'', bookfix.com, 2004., Web* Peter Seibel: ''Practical Common Lisp'', Apress, 2005., Web* Doug Hoyte: ''Let Over Lambda'', Lulu.com, 2008, , Web* George F. Luger, William A. Stubblefield: ''AI Algorithms, Data Structures, and Idioms in Prolog, Lisp and Java'', Addison Wesley, 2008, , PDF* Conrad Barski: ''Land of Lisp: Learn to program in Lisp, one game at a time!", "'', No Starch Press, 2010, , Web* Pavel Penev: ''Lisp Web Tales'', Leanpub, 2013, Web* Edmund Weitz: ''Common Lisp Recipes'', Apress, 2015, , Web* Patrick M. Krusenotto: ''Funktionale Programmierung und Metaprogrammierung, Interaktiv in Common Lisp'', Springer Fachmedien Wiesbaden 2016, , Web" ], [ "External links", "* Quicklisp - A very popular and high quality library manager for Common Lisp* The Awesome CL list, a curated list of Common Lisp frameworks and libraries.", "* The Common Lisp Cookbook, a collaborative project.", "* The CLiki, a Wiki for free and open-source Common Lisp systems running on Unix-like systems.", "* One of the main repositories for free Common Lisp for software is Common-Lisp.net .", "* lisp-lang.org has documentation and a showcase of success stories.", "* An overview of the history of Common Lisp: * Common Lisp Quick Reference – a compact overview of the Common Lisp standard language.", "* Planet Lisp Articles about Common Lisp.", "* Quickdocs summarizes documentation and dependency information for many Quicklisp projects." ] ]
wikipedia
[ [ "Color code" ], [ "Introduction", "25-pair color code chart used in certain kinds of wiring.A '''color code''' is a system for encoding and representing non-color information with colors to facilitate communication.", "This information tends to be categorical (representing unordered/qualitative categories) though may also be sequential (representing an ordered/quantitative variable)." ], [ "History", "The earliest examples of color codes in use are for long-distance communication by use of flags, as in semaphore communication.", "The United Kingdom adopted a color code scheme for such communication wherein red signified danger and white signified safety, with other colors having similar assignments of meaning.As chemistry and other technologies advanced, it became expedient to use coloration as a signal for telling apart things that would otherwise be confusingly similar, such as wiring in electrical and electronic devices, and pharmaceutical pills." ], [ "Encoded Variable", "A color code encodes a variable, which may have different representations, where the color code type should match the variable type:*Categorical variable - the variable may represent discrete values of unordered qualitative data (e.g.", "race)**Binary variables are typically treated as a categorical variable (e.g.", "sex)*Quantitative variable - the variable represents ordered, quantitative data (e.g.", "age)**Discrete quantitative data (e.g.", "the 6 sides of a die: 1,2,3,4,5,6) are sometimes treated as a categorical variable, despite the ordered nature." ], [ "Types", "The types of color code are:*'''Categorical''' - the colors are unordered, but are chosen to maximize saliency of the colors, by maximizing color difference between all color pair permutations.", "*'''Continuous''' - the colors are ordered and form a smooth color gradient.", "*'''Discrete''' - only a subset of a continuous color code are used (still ordered), where each is distinguishable from the others.===Categorical===When color is the only varied attribute, the color code is ''unidimensional''.", "When other attributes are varied (e.g.", "shape, size), the code is ''multidimensional'', where the dimensions can be ''independent'' (each encoding separate variables) or ''redundant'' (encoding the same variable).", "Partial redundancy sees one variable as a subset of another.", "For example, playing card suits are multidimensional with color (black, red) and shape (club, diamond, heart, spade), which are partially redundant since clubs and spades are always black and diamonds and hearts are always red.", "Tasks using categorical color codes can be classified as identification tasks, where a single stimulus is shown and must be identified (connotatively or denotatively), versus search tasks, where a color stimulus must be found within a field of heterogenous stimuli.", "Performance in these tasks is measured by speed and/or accuracy.The ideal color scheme for a categorical color code depends on whether speed or accuracy is more important.", "Despite humans being able to distinguish 150 distinct colors along the hue dimension during comparative task, evidence supports that color schemes where colors differ only by hue (equal luminosity and colorfulness) should have a maximum of 8 categories with optimized stimulus spacing along the hue dimension, though this would not be color blind accessible.", "The IALA recommends categorical color codes in 7 colors: red, orange, yellow, green, blue, white & black.", "Adding redundant coding of luminosity and colorfulness adds information and increases speed and accuracy of color decoding tasks.", "Color codes are superior to others (encoding to letters, shape, size, etc.)", "in certain types of tasks.", "Adding color as a redundant attribute to a numeral or letter encoding in search tasks decreased time by 50-75%, but in unidimensional identification tasks, using alphanumeric or line inclination codes caused less errors than color codes.Several studies demonstrate a subjective preference for color codes over achromatic codes (e.g.", "shapes), even in studies where color coding did not increase performance over achromatic coding.", "Subjects reported the tasks as less monotonous and less inducing of eye strain and fatigue.The ability to discriminate color differences decreases rapidly as the visual angle subtends less than 12' (0.2° or ~2mm at a viewing distance of 50cm), so color stimulus of at least 3mm in diameter or thickness is recommended when the color is on paper or on a screen.", "Under normal conditions, colored backgrounds do not affect the interpretation of color codes, but chromatic (and/or low) illumination of surface color code can degrade performance." ], [ "Criticism", "Color codes present some potential problems.", "On forms and signage, the use of color can distract from black and white text.Color codes are often designed without consideration for accessibility to color blind and blind people, and may even be inaccessible for those with normal color vision, since use of many colors to code many variables can lead to use of confusingly similar colors.", "Only 15-40% of the colorblind can correctly name surface color codes with 8-10 color categories, most of which test as mildly colorblind.", "This finding uses ideal illumination; when dimmer illumination is used, performance drops sharply." ], [ "Examples", "Systems incorporating color-coding include:*In electricity:**25-pair color code – telecommunications wiring**Audio connectors**Video connectors**Optical fibers**Electrical wiring – AC power phase, neutral, and grounding wires**Electronic color code AKA resistor or EIA color code (today - IEC 60062:2016 )**Ethernet twisted-pair wiring – local area networks**Jumper cables used to jump-start a vehicle**PC99 connectors and ports**Surround sound ports and cables**Three-phase electric power (electrical wiring)*In video games**Health and magic points**To distinguish friend from foe, for instance in ''StarCraft'', ''Halo'', or ''League of Legends''**To distinguish rarity or quality of items in adventure and role-playing games*In navigation:**Characteristic light**Navigation light**Sea mark**Traffic lights*Other technology:**At point of sale (especially for packaging within a huge range of products: to quickly differentiate variants, brands, categories)**Bottled gases**Fire extinguishers**Kerbside collection **Pipe marking**Queen bee birth year code**Underground utility location**Hospital emergency codes often incorporate colors (such as the widely used \"Code Blue\" indicating a cardiac arrest),*In military use:**Homeland Security Advisory System**Artillery shells and other munitions, which are color-coded according to their pyrotechnic contents**List of Rainbow Codes**NATO Military Symbols for Land Based Systems**Rainbow Herbicides*In social functions:**Black hat hacking, white hat, grey hat**Blue-collar worker, white-collar worker, pink-collar worker, grey-collar, green-collar worker**Handkerchief code**ISO 22324, Guidelines for color-coded alerts in public warning** Cooper's Color Code of the combat mindset**Rank in Judo**Ribbon colors ''see:'' :Category:Ribbon symbolism* In religion:** Clerical vestments, frontals and altar hangings in Christian churches" ], [ "See also", "* Color coding in data visualization* Secondary notation" ], [ "References" ], [ "External links", "*" ] ]
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[ [ "CGI" ], [ "Introduction", "'''CGI''' may refer to:" ], [ "Technology", "* Computer-generated imagery, computer-graphic effects in films, television programs, and other visual media* Computer Graphics Interface, the low-level interface between the Graphical Kernel System and hardware* Common Gateway Interface, a standard for dynamic generation of web pages by a web server** CGI.pm, a Perl module for implementing Common Gateway Interface programs* Compacted graphite iron, a type of cast iron* Corrugated galvanised iron, a type of molded sheet metal* Cell Global Identity, a standard identifier for mobile phone cells" ], [ "Organizations", "* California Graduate Institute, an independent graduate school specializing in psychology* Catholic Guides of Ireland, a Girl Guide association* Chulabhorn Graduate Institute, a private graduate institute in Thailand* CGI Aero or RusAir, a Russian airline*CGI Inc., a multinational information technology and business process services company* Clinton Global Initiative, a forum created by former US President Bill Clinton to discuss global problems* Coast Guard Intelligence, the intelligence branch of the United States Coast Guard* Commission for the Management and Application of Geoscience Information* Compagnie Générale Immobiliere, a Moroccan real-estate development company* Consultative Group on Indonesia, a former consortium of donors to the Indonesian government* Cuerpo Guardia de Infantería, an Argentine police riot control service* General Commissariat of Information, the Comisaría General de Información is an intelligence service within the National Police Corps of Spain." ], [ "Other uses", "* Clinical global impression, a family of scales to assess treatment response associated with mental disorders* Cognitively Guided Instruction, an approach to mathematics teaching and learning* CpG islands, in genetics, genomic regions that contain a high frequency of CG dinucleotides* Cape Girardeau Regional Airport (IATA airport code: CGI), an airport in Missouri, US" ], [ "See also", "* *" ] ]
wikipedia
[ [ "Cortex" ], [ "Introduction", "'''Cortex''' or '''cortical''' may refer to:" ], [ "Biology", "* Cortex (anatomy), the outermost layer of an organ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain''*** Motor cortex, the regions of the cerebral cortex involved in voluntary motor functions*** Prefrontal cortex, the anterior part of the frontal lobes of the brain*** Visual cortex, regions of the cerebral cortex involved in visual functions** Cerebellar cortex, the outer layer of the vertebrate cerebellum** Renal cortex, the outer portion of the kidney** Adrenal cortex, a portion of the adrenal gland* Cell cortex, the region of a cell directly underneath the membrane* Cortex (hair), the middle layer of a strand of hair* Cortex (botany), the outer portion of the stem or root of a plant" ], [ "Entertainment", "* ''Cortex'' (film), a 2008 French film directed by Nicolas Boukhrief* Cortex (podcast), a 2015 podcast* Doctor Neo Cortex, a fictional character in the ''Crash Bandicoot'' video game series** Nina Cortex, the niece of Neo Cortex* Cortex (band), a French jazz funk band featuring Alain Mion* Cortex, a Swedish post-punk alternative band featuring Freddie Wadling" ], [ "Other uses", "* Cortex (archaeology), the outer layer of rock formed on the exterior of raw materials by chemical and mechanical weathering processes* ''Cortex'' (journal), cognitive science journal published by Elsevier* Cortex, a family of the ARM architecture of CPUs* Cortex, a division of Gemini Sound Products* Cortex, a digital lending platform by Think Finance* Cortex Pharmaceuticals, a company of New Jersey, United States* Cortex Innovation Community, a district in St. Louis, Missouri, United States" ], [ "See also", "* * * Cordtex, a type of detonating cord used in mining* Corex (disambiguation)" ] ]
wikipedia
[ [ "Collection" ], [ "Introduction", "'''Collection''' or '''Collections''' may refer to:* Cash collection, the function of an accounts receivable department* Collection (church), money donated by the congregation during a church service* Collection agency, agency to collect cash* Collections management (museum)** Collection (museum), objects in a particular field forms the core basis for the museum** Fonds in archives** Private collection, sometimes just called \"collection\"* Collection (Oxford colleges), a beginning-of-term exam or Principal's Collections* Collection (horse), a horse carrying more weight on his hindquarters than his forehand* Collection (racehorse), an Irish-bred, Hong Kong based Thoroughbred racehorse* Collection (publishing), a gathering of books under the same title at the same publisher* Scientific collection, any systematic collection of objects for scientific study'''Collection''' may also refer to:" ], [ "Computing", "* Collection (abstract data type), the abstract concept of collections in computer science* Collection (linking), the act of linkage editing in computing* Garbage collection (computing), automatic memory management method" ], [ "Mathematics", "* Set (mathematics)* Class (set theory)* Family of sets* Indexed family* Multiset* Parametric family" ], [ "Albums", "===Collection===* ''Collection'' (2NE1 album), 2012* ''Collection'' (Agnes album), 2013* ''Collection'' (Arvingarna album), 2002* ''Collection'' (Jason Becker album), 2008* ''Collection'' (Tracy Chapman album), 2001* ''Collection'' (The Charlatans album)* ''Collection'' (Dave Grusin album), 1989* ''Collection'' (The Jam album)* ''Collection'' (Wynonna Judd album)* ''Collection'' (Magnus Uggla album), 1985* ''Collection'' (Men Without Hats album), 1996* ''Collection'' (MFÖ album), 2003* ''Collection'' (Mike Oldfield album), 2002* ''Collection'' (Praxis album), 1998* ''Collection'' (The Rankin Family album), 1996* ''Collection'' (Lee Ritenour album), 1991* ''Collection'' (Joe Sample album), 1991* ''Collection'' (Spyro Gyra album), 1991* ''Collection'' (The Stranglers album), 1998* ''Collection'' (Suicidal Tendencies album), 1993* ''Collection'' (Thee Michelle Gun Elephant album), 2001* ''Collection'' (The Warratahs album), 2003* ''Collection: The Shrapnel Years'' (Greg Howe album), 2006* ''Collection: The Shrapnel Years'' (Tony MacAlpine album), 2006* ''Collection: The Shrapnel Years'' (Vinnie Moore album), 2006* ''Collection I'', a 1986 compilation album of songs by the Misfits* ''Collection II'', a 1995 companion album to the Misfits' ''Collection I''===Collections===* ''Collections'' (Alexia album)* ''Collections'' (Rick Astley album), 2006* ''Collections'' (Cypress Hill album)* ''Collections'' (Terence Trent D'Arby album), 2006* ''Collections'' (Delphic album), 2013* ''Collections'' (Amanda Marshall album), 2006* ''Collections'' (Charlie Major album), 2006* ''Collections'' (Red Norvo, Art Pepper, Joe Morello and Gerry Wiggins album), 1957* ''Collections'' (Yanni album), 2008* ''Collections'' (The Young Rascals album), 1967" ], [ "Other uses", "* ''Collection'' (film), a 2021 film starring Alex Petttyfer* Collection #1, a database of sets of email addresses and passwords* Collections care, to prevent or delay the deterioration of cultural heritage* Collection class, in object-oriented programming* Generated collection, a musical scale formed by repeatedly adding a constant interval around the chromatic circle" ], [ "See also", "* A Collection (disambiguation)* Aggregate (disambiguation) * Collected (disambiguation)* Collecting* Collector (disambiguation)" ] ]
wikipedia
[ [ "Cauchy sequence" ], [ "Introduction", "In mathematics, a '''Cauchy sequence''' is a sequence whose elements become arbitrarily close to each other as the sequence progresses.", "More precisely, given any small positive distance, all excluding a finite number of elements of the sequence are less than that given distance from each other.", "Cauchy sequences are named after Augustin-Louis Cauchy; they may occasionally be known as '''fundamental sequences'''.It is not sufficient for each term to become arbitrarily close to the term.", "For instance, in the sequence of square roots of natural numbers:the consecutive terms become arbitrarily close to each other – their differencestend to zero as the index grows.", "However, with growing values of , the terms become arbitrarily large.", "So, for any index and distance , there exists an index big enough such that As a result, no matter how far one goes, the remaining terms of the sequence never get close to ; hence the sequence is not Cauchy.The utility of Cauchy sequences lies in the fact that in a complete metric space (one where all such sequences are known to converge to a limit), the criterion for convergence depends only on the terms of the sequence itself, as opposed to the definition of convergence, which uses the limit value as well as the terms.", "This is often exploited in algorithms, both theoretical and applied, where an iterative process can be shown relatively easily to produce a Cauchy sequence, consisting of the iterates, thus fulfilling a logical condition, such as termination.", "Generalizations of Cauchy sequences in more abstract uniform spaces exist in the form of Cauchy filters and Cauchy nets." ], [ "In real numbers", "A sequenceof real numbers is called a Cauchy sequence if for every positive real number there is a positive integer ''N'' such that for all natural numbers where the vertical bars denote the absolute value.", "In a similar way one can define Cauchy sequences of rational or complex numbers.", "Cauchy formulated such a condition by requiring to be infinitesimal for every pair of infinite ''m'', ''n''.For any real number ''r'', the sequence of truncated decimal expansions of ''r'' forms a Cauchy sequence.", "For example, when this sequence is (3, 3.1, 3.14, 3.141, ...).", "The ''m''th and ''n''th terms differ by at most when ''m'' < ''n'', and as ''m'' grows this becomes smaller than any fixed positive number ===Modulus of Cauchy convergence===If is a sequence in the set then a ''modulus of Cauchy convergence'' for the sequence is a function from the set of natural numbers to itself, such that for all natural numbers and natural numbers Any sequence with a modulus of Cauchy convergence is a Cauchy sequence.", "The existence of a modulus for a Cauchy sequence follows from the well-ordering property of the natural numbers (let be the smallest possible in the definition of Cauchy sequence, taking to be ).", "The existence of a modulus also follows from the principle of countable choice.", "''Regular Cauchy sequences'' are sequences with a given modulus of Cauchy convergence (usually or ).", "Any Cauchy sequence with a modulus of Cauchy convergence is equivalent to a regular Cauchy sequence; this can be proven without using any form of the axiom of choice.Moduli of Cauchy convergence are used by constructive mathematicians who do not wish to use any form of choice.", "Using a modulus of Cauchy convergence can simplify both definitions and theorems in constructive analysis.", "Regular Cauchy sequences were used by and by in constructive mathematics textbooks." ], [ "In a metric space", "Since the definition of a Cauchy sequence only involves metric concepts, it is straightforward to generalize it to any metric space ''X''.", "To do so, the absolute value is replaced by the distance (where ''d'' denotes a metric) between and Formally, given a metric space a sequenceis Cauchy, if for every positive real number there is a positive integer such that for all positive integers the distanceRoughly speaking, the terms of the sequence are getting closer and closer together in a way that suggests that the sequence ought to have a limit in ''X''.", "Nonetheless, such a limit does not always exist within ''X'': the property of a space that every Cauchy sequence converges in the space is called ''completeness'', and is detailed below." ], [ "Completeness", "A metric space (''X'', ''d'') in which every Cauchy sequence converges to an element of ''X'' is called complete.===Examples===The real numbers are complete under the metric induced by the usual absolute value, and one of the standard constructions of the real numbers involves Cauchy sequences of rational numbers.", "In this construction, each equivalence class of Cauchy sequences of rational numbers with a certain tail behavior—that is, each class of sequences that get arbitrarily close to one another— is a real number.A rather different type of example is afforded by a metric space ''X'' which has the discrete metric (where any two distinct points are at distance 1 from each other).", "Any Cauchy sequence of elements of ''X'' must be constant beyond some fixed point, and converges to the eventually repeating term.===Non-example: rational numbers===The rational numbers are not complete (for the usual distance):There are sequences of rationals that converge (in ) to irrational numbers; these are Cauchy sequences having no limit in In fact, if a real number ''x'' is irrational, then the sequence (''x''''n''), whose ''n''-th term is the truncation to ''n'' decimal places of the decimal expansion of ''x'', gives a Cauchy sequence of rational numbers with irrational limit ''x''.", "Irrational numbers certainly exist in for example:* The sequence defined by consists of rational numbers (1, 3/2, 17/12,...), which is clear from the definition; however it converges to the irrational square root of 2, see Babylonian method of computing square root.", "* The sequence of ratios of consecutive Fibonacci numbers which, if it converges at all, converges to a limit satisfying and no rational number has this property.", "If one considers this as a sequence of real numbers, however, it converges to the real number the Golden ratio, which is irrational.", "* The values of the exponential, sine and cosine functions, exp(''x''), sin(''x''), cos(''x''), are known to be irrational for any rational value of but each can be defined as the limit of a rational Cauchy sequence, using, for instance, the Maclaurin series.===Non-example: open interval===The open interval in the set of real numbers with an ordinary distance in is not a complete space: there is a sequence in it, which is Cauchy (for arbitrarily small distance bound all terms of fit in the interval), however does not converge in — its 'limit', number 0, does not belong to the space ===Other properties===* Every convergent sequence (with limit ''s'', say) is a Cauchy sequence, since, given any real number beyond some fixed point, every term of the sequence is within distance of ''s'', so any two terms of the sequence are within distance of each other.", "* In any metric space, a Cauchy sequence is bounded (since for some ''N'', all terms of the sequence from the ''N''-th onwards are within distance 1 of each other, and if ''M'' is the largest distance between and any terms up to the ''N''-th, then no term of the sequence has distance greater than from ).", "* In any metric space, a Cauchy sequence which has a convergent subsequence with limit ''s'' is itself convergent (with the same limit), since, given any real number ''r'' > 0, beyond some fixed point in the original sequence, every term of the subsequence is within distance ''r''/2 of ''s'', and any two terms of the original sequence are within distance ''r''/2 of each other, so every term of the original sequence is within distance ''r'' of ''s''.These last two properties, together with the Bolzano–Weierstrass theorem, yield one standard proof of the completeness of the real numbers, closely related to both the Bolzano–Weierstrass theorem and the Heine–Borel theorem.", "Every Cauchy sequence of real numbers is bounded, hence by Bolzano–Weierstrass has a convergent subsequence, hence is itself convergent.", "This proof of the completeness of the real numbers implicitly makes use of the least upper bound axiom.", "The alternative approach, mentioned above, of the real numbers as the completion of the rational numbers, makes the completeness of the real numbers tautological.One of the standard illustrations of the advantage of being able to work with Cauchy sequences and make use of completeness is provided by consideration of the summation of an infinite series of real numbers(or, more generally, of elements of any complete normed linear space, or Banach space).", "Such a series is considered to be convergent if and only if the sequence of partial sums is convergent, where It is a routine matter to determine whether the sequence of partial sums is Cauchy or not, since for positive integers If is a uniformly continuous map between the metric spaces ''M'' and ''N'' and (''x''''n'') is a Cauchy sequence in ''M'', then is a Cauchy sequence in ''N''.", "If and are two Cauchy sequences in the rational, real or complex numbers, then the sum and the product are also Cauchy sequences." ], [ "Generalizations", "===In topological vector spaces===There is also a concept of Cauchy sequence for a topological vector space : Pick a local base for about 0; then () is a Cauchy sequence if for each member there is some number such that whenever is an element of If the topology of is compatible with a translation-invariant metric the two definitions agree.===In topological groups===Since the topological vector space definition of Cauchy sequence requires only that there be a continuous \"subtraction\" operation, it can just as well be stated in the context of a topological group: A sequence in a topological group is a Cauchy sequence if for every open neighbourhood of the identity in there exists some number such that whenever it follows that As above, it is sufficient to check this for the neighbourhoods in any local base of the identity in As in the construction of the completion of a metric space, one can furthermore define the binary relation on Cauchy sequences in that and are equivalent if for every open neighbourhood of the identity in there exists some number such that whenever it follows that This relation is an equivalence relation: It is reflexive since the sequences are Cauchy sequences.", "It is symmetric since which by continuity of the inverse is another open neighbourhood of the identity.", "It is transitive since where and are open neighbourhoods of the identity such that ; such pairs exist by the continuity of the group operation.===In groups===There is also a concept of Cauchy sequence in a group :Let be a decreasing sequence of normal subgroups of of finite index.Then a sequence in is said to be Cauchy (with respect to ) if and only if for any there is such that for all Technically, this is the same thing as a topological group Cauchy sequence for a particular choice of topology on namely that for which is a local base.The set of such Cauchy sequences forms a group (for the componentwise product), and the set of null sequences (sequences such that ) is a normal subgroup of The factor group is called the completion of with respect to One can then show that this completion is isomorphic to the inverse limit of the sequence An example of this construction familiar in number theory and algebraic geometry is the construction of the -adic completion of the integers with respect to a prime In this case, is the integers under addition, and is the additive subgroup consisting of integer multiples of If is a cofinal sequence (that is, any normal subgroup of finite index contains some ), then this completion is canonical in the sense that it is isomorphic to the inverse limit of where varies over normal subgroups of finite index.", "For further details, see Ch.", "I.10 in Lang's \"Algebra\".===In a hyperreal continuum===A real sequence has a natural hyperreal extension, defined for hypernatural values ''H'' of the index ''n'' in addition to the usual natural ''n''.", "The sequence is Cauchy if and only if for every infinite ''H'' and ''K'', the values and are infinitely close, or adequal, that is,: where \"st\" is the standard part function.===Cauchy completion of categories=== introduced a notion of Cauchy completion of a category.", "Applied to (the category whose objects are rational numbers, and there is a morphism from ''x'' to ''y'' if and only if ), this Cauchy completion yields (again interpreted as a category using its natural ordering)." ], [ "See also", "* *" ], [ "References" ], [ "Further reading", "******* (for uses in constructive mathematics)" ], [ "External links", "*" ] ]
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[ [ "Common Era" ], [ "Introduction", "'''Common Era''' ('''CE''') and '''Before the Common Era''' ('''BCE''') are year notations for the Gregorian calendar (and its predecessor, the Julian calendar), the world's most widely used calendar era.", "Common Era and Before the Common Era are alternatives to the original Anno Domini (AD) and Before Christ (BC) notations used for the same calendar era.", "The two notation systems are numerically equivalent: \" CE\" and \"AD \" each describe the current year; \"400 BCE\" and \"400 BC\" are the same year.The expression can be traced back to 1615, when it first appears in a book by Johannes Kepler as the (), and to 1635 in English as \"Vulgar Era\".", "The term \"Common Era\" can be found in English as early as 1708, and became more widely used in the mid-19th century by Jewish religious scholars.", "Since the late 20th century, BCE and CE have become popular in academic and scientific publications on the grounds that BCE and CE are religiously neutral terms.", "They have been promoted as more sensitive to non-Christians by not referring to Jesus, the central figure of Christianity, especially via the religious terms \"Christ\" and (\"Lord\") utilized by the other abbreviations." ], [ "History", "=== Origins ===The idea of numbering years beginning from the date he believed to be the date of birth of Jesus, was conceived around the year 525 by the Christian monk Dionysius Exiguus.", "He did this to replace the then dominant Era of Martyrs system, because he did not wish to continue the memory of a tyrant who persecuted Christians.", "He numbered years from an initial reference date (\"epoch\"), an event he referred to as the Incarnation of Jesus.", "Dionysius labeled the column of the table in which he introduced the new era as \"''Anni Domini Nostri Jesu Christi''\" Year of our Lord Jesus Christ.This way of numbering years became more widespread in Europe with its use by Bede in England in 731.Bede also introduced the practice of dating years before what he supposed was the year of birth of Jesus, and the practice of not using a year zero.", "In 1422, Portugal became the last Western European country to switch to the system begun by Dionysius.=== Vulgar Era ===Johannes Kepler 15711630, the German astronomer, mathematician, astrologer, natural philosopher and writer on music.The term \"Common Era\" is traced back in English to its appearance as \"Vulgar Era\" to distinguish dates on the Gregorian calendar in popular use from dates of the regnal year (the year of the reign of a sovereign) typically used in national law.", "(The word 'vulgar' originally meant 'of the ordinary people', with no derogatory associations.", ")The first use of the Latin term may be that in a 1615 book by Johannes Kepler.", "Kepler uses it again, as , in a 1616 table of ephemerides, and again, as , in 1617.A 1635 English edition of that book has the title page in English that may be the earliest-found use of ''Vulgar Era'' in English.", "A 1701 book edited by John Le Clerc includes the phrase \"Before Christ according to the Vulgar Æra,6\".The Merriam Webster Dictionary gives 1716 as being the date of first use of the term \"vulgar era\" (to mean Christian era).", "The first published use of \"Christian Era\" may be the Latin phrase on the title page of a 1584 theology book, .", "In 1649, the Latin phrase appeared in the title of an English almanac.", "A 1652 ephemeris may be the first instance found so far of the English use of \"Christian Era\".The English phrase \"Common Era\" appears at least as early as 1708, and in a 1715 book on astronomy it is used interchangeably with \"Christian Era\" and \"Vulgar Era\".", "A 1759 history book uses ''common æra'' in a generic sense, to refer to \"the common era of the Jews\".", "The first use of the phrase \"before the common era\" may be that in a 1770 work that also uses ''common era'' and ''vulgar era'' as synonyms, in a translation of a book originally written in German.", "The 1797 edition of the Encyclopædia Britannica uses the terms ''vulgar era'' and ''common era'' synonymously.", "In 1835, in his book ''Living Oracles'', Alexander Campbell, wrote: \"The vulgar Era, or Anno Domini; the fourth year of Jesus Christ, the first of which was but eight days\", and also refers to the ''common era'' as a synonym for ''vulgar era'' with \"the fact that our Lord was born on the 4th year before the vulgar era, called Anno Domini, thus making (for example) the 42d year from his birth to correspond with the 38th of the common era\".", "The ''Catholic Encyclopedia'' (1909) in at least one article reports all three terms (Christian, Vulgar, Common Era) being commonly understood by the early 20th century.The phrase \"common era\", in lower case, also appeared in the 19th century in a 'generic' sense, not necessarily to refer to the Christian Era, but to any system of dates in common use throughout a civilization.", "Thus, \"the common era of the Jews\", \"the common era of the Mahometans\", \"common era of the world\", \"the common era of the foundation of Rome\".", "When it did refer to the Christian Era, it was sometimes qualified, e.g., \"common era of the Incarnation\", \"common era of the Nativity\", or \"common era of the birth of Christ\".An adapted translation of ''Common Era'' into Latin as was adopted in the 20th century by some followers of Aleister Crowley, and thus the abbreviation \"e.v.\"", "or \"EV\" may sometimes be seen as a replacement for AD.=== History of the use of the CE/BCE abbreviation ===Although Jews have their own Hebrew calendar, they often use the Gregorian calendar without the AD prefix.", "As early as 1825, the abbreviation VE (for Vulgar Era) was in use among Jews to denote years in the Western calendar.", ", Common Era notation has also been in use for Hebrew lessons for more than a century.", "Jews have also used the term '''Current Era'''." ], [ "Contemporary usage", "Some academics in the fields of theology, education, archaeology and history have adopted CE and BCE notation despite some disagreement.", "Several style guides now prefer or mandate its use.", "A study conducted in 2014 found that the BCE/CE notation is not growing at the expense of BC and AD notation in the scholarly literature, and that both notations are used in a relatively stable fashion.", "===United Kingdom===In 2002, an advisory panel for the religious education syllabus for England and Wales recommended introducing BCE/CE dates to schools, and by 2018 some local education authorities were using them.", "In 2018, the National Trust said it would continue to use BC/AD as its house style.", "English Heritage explains its era policy thus: \"It might seem strange to use a Christian calendar system when referring to British prehistory, but the BC/AD labels are widely used and understood.\"", "Some parts of the BBC use BCE/CE, but some presenters have said they will not.", "As of October 2019, the BBC News style guide has entries for AD and BC, but not for CE or BCE.The style guide for ''The Guardian'' says, under the entry for CE/BCE: \"some people prefer CE (common era, current era, or Christian era) and BCE (before common era, etc.)", "to AD and BC, which, however, remain our style\".===United States===In the United States, the use of the BCE/CE notation in textbooks was reported in 2005 to be growing.", "Some publications have transitioned to using it exclusively.", "For example, the 2007 World Almanac was the first edition to switch to BCE/CE, ending a period of 138 years in which the traditional BC/AD dating notation was used.", "BCE/CE is used by the College Board in its history tests, and by the Norton Anthology of English Literature.", "Others have taken a different approach.", "The US-based History Channel uses BCE/CE notation in articles on non-Christian religious topics such as Jerusalem and Judaism.", "The 2006 style guide for the Episcopal Diocese ''Maryland Church News'' says that BCE and CE should be used.In June 2006, in the United States, the Kentucky State School Board reversed its decision to use BCE and CE in the state's new Program of Studies, leaving education of students about these concepts a matter of local discretion.===Australia===In 2011, media reports suggested that the BC/AD notation in Australian school textbooks would be replaced by BCE/CE notation.", "The change drew opposition from some politicians and church leaders.", "Weeks after the story broke, the Australian Curriculum, Assessment and Reporting Authority denied the rumours and stated that the BC/AD notation would remain, with CE and BCE as an optional suggested learning activity.===Canada===In 2013, the Canadian Museum of Civilization (now the Canadian Museum of History) in Gatineau (opposite Ottawa), which had previously switched to BCE/CE, decided to change back to BC/AD in material intended for the public while retaining BCE/CE in academic content." ], [ "Rationales", "=== Support ===The use of CE in Jewish scholarship was historically motivated by the desire to avoid the implicit \"Our Lord\" in the abbreviation ''AD''.", "Although other aspects of dating systems are based in Christian origins, AD is a direct reference to Jesus as Lord.Proponents of the Common Era notation assert that the use of BCE/CE shows sensitivity to those who use the same year numbering system as the one that originated with and is currently used by Christians, but who are not themselves Christian.Former United Nations Secretary-General Kofi Annan has argued:Adena K. Berkowitz, in her application to argue before the United States Supreme Court, opted to use BCE and CE because \"Given the multicultural society that we live in, the traditional Jewish designationsB.C.E.", "and C.E.", "cast a wider net of inclusion\".", "\"Non-Christian scholars, especially, embraced CE and BCE because they could now communicate more easily with the Christian community.", "Jewish, Islamic, Hindu and Buddhist scholars could retain their own calendar but refer to events using the Gregorian Calendar as BCE and CE without compromising their own beliefs about the divinity of Jesus of Nazareth\".=== Opposition ===Some critics often note the fact that there is no difference in the epoch of the two systems, a moment about four to seven years after the date of birth of Jesus of Nazareth.", "BCE and CE are still aligned with BC and AD, which denote the periods before and after Jesus was born.Some Christians are offended by the removal of the reference to Jesus in the Common Era notation.", "The Southern Baptist Convention supports retaining the BC/AD abbreviations.Roman Catholic priest and writer on interfaith issues Raimon Panikkar argued that the BCE/CE usage is the less inclusive option, since they are still using the Christian calendar numbers, forcing it on other nations.", "In 1993, the English-language expert Kenneth G. Wilson speculated a slippery slope scenario in his style guide that \"if we do end by casting aside the AD/BC convention, almost certainly some will argue that we ought to cast aside as well the conventional numbering system that is, the method of numbering years itself, given its Christian basis.\"" ], [ "Conventions in style guides", "The abbreviation BCE, just as with BC, always follows the year number.", "Unlike AD, which still often precedes the year number, CE always follows the year number (if context requires that it be written at all).", "Thus, the current year is written as in both notations (or, if further clarity is needed, as CE, or as AD ), and the year that Socrates died is represented as 399 BCE (the same year that is represented by 399 BC in the BC/AD notation).", "The abbreviations are sometimes written with small capital letters, or with periods (e.g., \"B.C.E.\"", "or \"C.E.\").", "The US-based Society of Biblical Literature style guide for academic texts on religion prefers BCE/CE to BC/AD." ], [ "Similar conventions in other languages", "* In Germany, Jews in Berlin seem to have already been using words translating to \"(before the) common era\" in the 18th century, while others like Moses Mendelssohn opposed this usage as it would hinder the integration of Jews into German society.", "The formulation seems to have persisted among German Jews in the 19th century in forms like (before the common chronology).", "In 1938 Nazi Germany the use of this convention was also prescribed by the National Socialist Teachers League.", "However, it was soon discovered that many German Jews had been using the convention ever since the 18th century, and ''Time'' magazine found it ironic to see \"Aryans following Jewish example nearly 200 years later\".", "* In Spanish, common forms used for \"BC\" are and (for \"\", \"before Christ\"), with variations in punctuation and sometimes the use of () instead of .", "The also acknowledges the use of () and ().", "In scholarly writing, is the equivalent of the English \"BCE\", \"\" or \"Before the Common Era\".", "* In Welsh, OC can be expanded to equivalents of both AD () and CE (); for dates before the Common Era, CC (traditionally, ) is used exclusively, as would abbreviate to a mild obscenity.", "* In Russian since the October Revolution (1917) , lit.", "''before our era'') and lit.", "''of our era'') are used almost universally.", "Within Christian churches , i.e.", "''before/after the birth of Christ'', equivalent to ) remains in use.", "* In Polish, \"p.n.e.\"", "(, lit.", "''before our era'') and \"n.e.\"", "(, lit.", "''of our era'') are commonly used in historical and scientific literature.", "(''before Christ'') and (''after Christ'') see sporadic usage, mostly in religious publications.", "*In China, upon the foundation of the Republic of China, the Government in Nanking adopted the Republic of China calendar with 1912 designated as year 1, but used the Western calendar for international purposes.", "The translated term was (, \"Western Era\"), which is still used in Taiwan in formal documents.", "In 1949, the People's Republic of China adopted (, \"Common Era\") for both internal and external affairs in mainland China.", "This notation was extended to Hong Kong in 1997 and Macau in 1999 (de facto extended in 1966) through Annex III of Hong Kong Basic Law and Macau Basic Law, thus eliminating the ROC calendar in these areas.", "BC is translated into Chinese as (, \"Before the Common Era\").", "* In Czech, the \"n. l.\" ( which translates as ''of our year count'') and \"př.", "n. l.\" or \"před n. l.\" ( meaning ''before our year count'') is used, always after the year number.", "The direct translation of AD (, abbreviated as ''L.", "P.'') or BC (, abbreviated as ''př.", "Kr.'')", "is seen as archaic.", "*In Croatian the common form used for ''BC'' and ''AD'' are ''pr.", "Kr.''", "(''prije Krista'', \"before Christ\") and ''p.", "Kr.''", "(''poslije Krista'', ''after Christ'').", "The abbreviations ''pr.", "n. e.'' (''prije nove ere, before new era'') and ''n.", "e. (nove ere, (of the) new era'') have also recently been introduced.", "* In Danish, \"f.v.t.\"", "(, ''before our time reckoning'') and \"e.v.t.\"", "(, ''after our time reckoning'') are used as BCE/CE are in English.", "Also commonly used are \"f.Kr.\"", "(, ''before Christ'') and \"e.Kr.\"", "(, ''after Christ''), which are both placed after the year number in contrast with BC/AD in English.", "* In Macedonian, the terms \"п.н.е.\"", "(пред нашата ера \"before our era\") and \"н.е.\"", "(наша ера \"our era\") are used in every aspect.", "* In Estonian, \"e.m.a.\"", "(, ''before our time reckoning'') and \"m.a.j.\"", "(, ''according to our time reckoning'') are used as BCE and CE, respectively.", "Also in use are terms \"eKr\" (, ''before Christ'') and \"pKr\" (, ''after Christ'').", "In all cases, the abbreviation is written after the year number.", "* In Finnish, \"eaa.\"", "(, ''before time reckoning'') and \"jaa.\"", "(, ''after the start of time reckoning'') are used as BCE and CE, respectively.", "Also (decreasingly) in use are terms \"eKr\", (, ''before Christ'') and \"jKr\".", "(, ''after Christ'').", "In all cases, the abbreviation is written after the year number." ], [ "See also", "* Astronomical year numbering* Before Present* Calendar* Calendar reform* Holocene Era* List of calendars" ], [ "Notes" ], [ "References" ], [ "External links", "* *" ] ]
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[ [ "Charles Robert Malden" ], [ "Introduction", "'''Charles Robert Malden''' (9 August 1797 – 23 May 1855), was a nineteenth-century British naval officer, surveyor and educator.", "He is the discoverer of Malden Island in the central Pacific, which is named in his honour.", "He also founded Windlesham House School at Brighton, England." ], [ "Biography", "Malden was born in Putney, Surrey, son of Jonas Malden, a surgeon.", "He entered British naval service at the age of 11 on 22 June 1809.He served nine years as a volunteer 1st class, midshipman, and shipmate, including one year in the English Channel and Bay of Biscay (1809), four years at the Cape of Good Hope and in the East Indies (1809–14), two and a half years on the North American and West Indian stations (1814–16), and a year and a half in the Mediterranean (1817–18).", "He was present at the capture of Mauritius and Java, and at the battles of Baltimore and New Orleans.He passed the examination in the elements of mathematics and the theory of navigation at the Royal Naval Academy on 2–4 September 1816, and became a 1st Lieutenant on 1 September 1818.In eight years of active service as an officer, he served two and a half years in a surveying ship in the Mediterranean (1818–21), one and a half years in a surveying sloop in the English Channel and off the coast of Ireland (1823–24), and one and a half years as Surveyor of the frigate during a voyage (1824–26) to and from the Hawaiian Islands (then known as the \"Sandwich islands\").In Hawaii he surveyed harbours which, he noted, were \"said not to exist by Captains Cook and Vancouver.\"", "On the return voyage he discovered and explored uninhabited Malden Island in the central Pacific on 30 July 1825.After his return he left active service but remained at half pay.", "He served for several years as hydrographer to King William IV.He married Frances Cole, daughter of Rev.", "William Hodgson Cole, rector of West Clandon and Vicar of Wonersh, near Guildford, Surrey, on 8 April 1828.Malden became the father of seven sons and a daughter.From 1830 to 1836 he took pupils for the Royal Navy at Ryde, Isle of Wight.", "He purchased the school of Henry Worsley at Newport, Isle of Wight, in December 1836, reopened it as a preparatory school on 20 February 1837, and moved it to Montpelier Road in Brighton in December 1837.He built the Windlesham House School at Brighton in 1844, and conducted the school until his death there in 1855.He was succeeded as headmaster by his son Henry Charles Malden." ], [ "References" ], [ "Further reading", "*" ] ]
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[ [ "CPD" ], [ "Introduction", "'''CPD''' may refer to:" ], [ "Science and technology", "* CPD (gene), a human gene encoding the protein Carboxypeptidase D* Chronic pulmonary disease, a pathological condition* Cephalopelvic disproportion, when the capacity of the pelvis is inadequate to allow the fetus to negotiate the birth canal* Cyclobutane pyrimidine dimer, a common UV product* Cyclopentadiene, an organic compound* Canonical polyadic decomposition, in mathematics* Copy/Paste Detector, software to find duplicate computer code* Chemical compound, a substance formed by chemical union* Cyproterone acetate, a progestin and antiandrogen* Conditional probability distribution, a kind of distribution in statistics" ], [ "Organizations", "* Centre for Policy Development, an Australian think tank* Centre for Policy Dialogue, Bangladesh* Centres of Plant Diversity, a classification initiative* Commission on Presidential Debates, a US nonprofit* Committee on the Present Danger, an American foreign policy interest group===Police===* Cambridge Police Department (Massachusetts)*Camden Police Department (New Jersey), a defunct police department dissolved in 2012* Carmel Police Department (Indiana)* Charleston Police Department (West Virginia)* Chattanooga Police Department, Tennessee* Chicago Police Department, Illinois* Cincinnati Police Department, Ohio* Cleveland Police Department, Ohio* Columbus Police Department, Ohio* Town of Carmel Police Department (New York)" ], [ "Other uses", "* Carnet de Passages en Douane, a customs document* Collaborative product development, in business* The Constitutional Practice and Discipline of the Methodist Church of Great Britain* Construction Products Directive, a repealed EU Directive* Continuing professional development* ''Danio margaritatus'' (also known as the Celestial Pearl Danio), a fish native to Southeast Asia* Coober Pedy Airport, IATA airport code \"CPD\"" ], [ "See also", "* Congress of People's Deputies (disambiguation)" ] ]
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[ [ "Chechnya" ], [ "Introduction", "Nikaroi combat tower'''Chechnya''', officially the '''Chechen Republic''', is a republic of Russia.", "It is situated in the North Caucasus of Eastern Europe, between the Caspian Sea and Black Sea.", "The republic forms a part of the North Caucasian Federal District, and shares land borders with the country of Georgia to its south; with the Russian republics of Dagestan, Ingushetia, and North Ossetia-Alania to its east, north, and west; and with Stavropol Krai to its northwest.Sharoy towersAfter the dissolution of the Soviet Union in 1991, the Checheno-Ingush ASSR split into two parts: the Republic of Ingushetia and the Chechen Republic.", "The latter proclaimed the Chechen Republic of Ichkeria, which declared independence, while the former sided with Russia.", "Following the First Chechen War of 1994–1996 with Russia, Chechnya gained ''de facto'' independence as the Chechen Republic of Ichkeria, although ''de jure'' it remained a part of Russia.", "Russian federal control was restored in the Second Chechen War of 1999–2009, with Chechen politics being dominated by the former Ichkerian Mufti Akhmad Kadyrov, and later his son Ramzan Kadyrov.Lake KezenoyamThe republic covers an area of , with a population of over 1.5 million residents .It is home to the indigenous Chechens, part of the Nakh peoples, and of primarily Muslim faith.", "Grozny is the capital and largest city." ], [ "History", "===Origin of Chechnya's population===According to Leonti Mroveli, the 11th-century Georgian chronicler, the word Caucasian is derived from the Nakh ancestor Kavkas.According to George Anchabadze of Ilia State University:American linguist Johanna Nichols \"has used language to connect the modern people of the Caucasus region to the ancient farmers of the Fertile Crescent\" and her research suggests that \"farmers of the region were proto-Nakh-Daghestanians\".", "Nichols stated: \"The Nakh–Dagestanian languages are the closest thing we have to a direct continuation of the cultural and linguistic community that gave rise to Western civilisation.", "\"===Prehistory===Map of the Caucasian isthmus by J. Grassl, 1856Traces of human settlement dating back to 40,000 BCE were found near Lake Kezanoi.", "Cave paintings, artifacts, and other archaeological evidence indicate continuous habitation for some 8,000 years.", "People living in these settlements used tools, fire, and clothing made of animal skins.The Caucasian Epipaleolithic and early Caucasian Neolithic era saw the introduction of agriculture, irrigation, and the domestication of animals in the region.", "Settlements near Ali-Yurt and Magas, discovered in modern times, revealed tools made out of stone: stone axes, polished stones, stone knives, stones with holes drilled in them, clay dishes etc.", "Settlements made out of clay bricks were discovered in the plains.", "In the mountains there were settlements made from stone and surrounded by walls; some of them dated back to 8000 BCE.", "This period also saw the appearance of the wheel (3000 BCE), horseback riding, metal works (copper, gold, silver, iron), dishes, armor, daggers, knives and arrow tips in the region.", "The artifacts were found near Nasare-Cort, Muzhichi, Ja-E-Bortz (alternatively known as Surkha-khi), Abbey-Gove (also known as Nazran or Nasare).=== Pre-imperial era ===The German scientist Peter Simon Pallas believed that the Vainakh people (Chechens and Ingush) were the direct descendants from Alania.", "In 1239, the Alania capital of Maghas and the Alan confederacy of the Northern Caucasian highlanders, nations, and tribes was destroyed by Batu Khan (a Mongol leader and a grandson of Genghis Khan).According to the missionary Pian de Carpine, a part of the Alans had successfully resisted a Mongol siege on a mountain for 12 years:This twelve year old siege is not found in any other report, however the Russian historian A. I. Krasnov connected this battle with two Chechen folktales he recorded in 1967 that spoke of an old hunter named Idig who with his companions defended the Dakuoh mountain for 12 years against Tatar-Mongols.", "He also reported to have found several arrowheads and spears from the 13th century near the very mountain at which the battle took place:In the 14th and 15th centuries, there was frequent warfare between the Chechens, Tamerlane and Tokhtamysh, culminating in the Battle of the Terek River (see Tokhtamysh–Timur war).", "The Chechen tribes built fortresses, castles, and defensive walls, protecting the mountains from the invaders.", "Part of the lowland tribes were occupied by Mongols.", "However, during the mid-14th century a strong Chechen Princedom called Simsim emerged under Khour II, a Chechen king that led the Chechen politics and wars.", "He was in charge of an army of Chechens against the rogue warlord Mamai and defeated him in the Battle of Tatar-tup in 1362.The kingdom of Simsim was almost destroyed during the Timurid invasion of the Caucasus, when Khour II allied himself with the Golden Horde Khan Tokhtamysh in the Battle of the Terek River.", "Timur sought to punish the highlanders for their allegiance to Tokhtamysh and as a consequence invaded Simsim in 1395.The 16th century saw the first Russian involvement in the Caucasus.", "In 1558, Temryuk of Kabarda sent his emissaries to Moscow requesting help from Ivan the Terrible against the Vainakh tribes.", "Ivan the Terrible married Temryuk's daughter Maria Temryukovna.", "An alliance was formed to gain the ground in the central Caucasus for the expanding Tsardom of Russia against stubborn Vainakh defenders.", "Chechnya was a nation in the Northern Caucasus that fought against foreign rule continually since the 15th century.", "Several Chechen leaders such as the 17th century Mehk-Da Aldaman Gheza led the Chechen politics and fought off encroachments of foreign powers.", "He defended the borders of Chechnya from invasions of Kabardinians and Avars during the Battle of Khachara in 1667.The Chechens converted over the next few centuries to Sunni Islam, as Islam was associated with resistance to Russian encroachment.===Imperial rule===Captured Imam Shamil before the commander-in-chief Prince Bariatinsky on 25 August 1859; painting by Theodor HorscheltPeter the Great first sought to increase Russia's political influence in the Caucasus and the Caspian Sea at the expense of Safavid Persia when he launched the Russo-Persian War of 1722–1723.Russian forces succeeded in taking much of the Caucasian territories from Iran for several years.As the Russians took control of the Caspian corridor and moved into Persian-ruled Dagestan, Peter's forces ran into mountain tribes.", "Peter sent a cavalry force to subdue them, but the Chechens routed them.", "In 1732, after Russia already ceded back most of the Caucasus to Persia, now led by Nader Shah, following the Treaty of Resht, Russian troops clashed again with Chechens in a village called Chechen-aul along the Argun River.", "The Russians were defeated again and withdrew, but this battle is responsible for the apocryphal story about how the Nokchi came to be known as \"Chechens\" – the people ostensibly named for the place the battle had taken place.", "The name Chechen was however already used since as early as 1692.Under intermittent Persian rule since 1555, in 1783 the eastern Georgians of Kartl-Kakheti led by Erekle II and Russia signed the Treaty of Georgievsk.", "According to this treaty, Kartl-Kakheti received protection from Russia, and Georgia abjured any dependence on Iran.", "In order to increase its influence in the Caucasus and to secure communications with Kartli and other Christian regions of the Transcaucasia which it considered useful in its wars against Persia and Turkey, the Russian Empire began conquering the Northern Caucasus mountains.", "The Russian Empire used Christianity to justify its conquests, allowing Islam to spread widely because it positioned itself as the religion of liberation from tsardom, which viewed Nakh tribes as \"bandits\".", "The rebellion was led by Mansur Ushurma, a Chechen Naqshbandi (Sufi) sheikh—with wavering military support from other North Caucasian tribes.", "Mansur hoped to establish a Transcaucasus Islamic state under sharia law.", "He was unable to fully achieve this because in the course of the war he was betrayed by the Ottomans, handed over to Russians, and executed in 1794.Following the forced ceding of the current territories of Dagestan, most of Azerbaijan, and Georgia by Persia to Russia, following the Russo-Persian War of 1804–1813 and its resultant Treaty of Gulistan, Russia significantly widened its foothold in the Caucasus at the expense of Persia.", "Another successful Caucasus war against Persia several years later, starting in 1826 and ending in 1828 with the Treaty of Turkmenchay, and a successful war against Ottoman Turkey in 1828 and 1829, enabled Russia to use a much larger portion of its army in subduing the natives of the North Caucasus.Chechen artillerymenThe resistance of the Nakh tribes never ended and was a fertile ground for a new Muslim-Avar commander, Imam Shamil, who fought against the Russians from 1834 to 1859 (see Murid War).", "In 1859, Shamil was captured by Russians at aul Gunib.", "Shamil left Baysangur of Benoa, a Chechen with one arm, one eye, and one leg, in charge of command at Gunib.", "Baysangur broke through the siege and continued to fight Russia for another two years until he was captured and killed by Russians.", "The Russian tsar hoped that by sparing the life of Shamil, the resistance in the North Caucasus would stop, but it did not.", "Russia began to use a colonization tactic by destroying Nakh settlements and building Cossack defense lines in the lowlands.", "The Cossacks suffered defeat after defeat and were constantly attacked by mountaineers, who were robbing them of food and weaponry.The tsarists' regime used a different approach at the end of the 1860s.", "They offered Chechens and Ingush to leave the Caucasus for the Ottoman Empire (see Muhajir (Caucasus)).", "It is estimated that about 80% of Chechens and Ingush left the Caucasus during the deportation.", "It weakened the resistance which went from open warfare to insurgent warfare.", "One of the notable Chechen resistance fighters at the end of the 19th century was a Chechen abrek Zelimkhan Gushmazukaev and his comrade-in-arms Ingush abrek Sulom-Beck Sagopshinski.", "Together they built up small units which constantly harassed Russian military convoys, government mints, and government post-service, mainly in Ingushetia and Chechnya.", "Ingush aul Kek was completely burned when the Ingush refused to hand over Zelimkhan.", "Zelimkhan was killed at the beginning of the 20th century.", "The war between Nakh tribes and Russia resurfaced during the times of the Russian Revolution, which saw the Nakh struggle against Anton Denikin and later against the Soviet Union.On 21 December 1917, Ingushetia, Chechnya, and Dagestan declared independence from Russia and formed a single state: \"United Mountain Dwellers of the North Caucasus\" (also known as the Mountainous Republic of the Northern Caucasus) which was recognized by major world powers.", "The capital of the new state was moved to Temir-Khan-Shura (Dagestan).", "Tapa Tchermoeff, a prominent Chechen statesman, was elected the first prime minister of the state.", "The second prime minister elected was Vassan-Girey Dzhabagiev, an Ingush statesman, who also was the author of the constitution of the republic in 1917, and in 1920 he was re-elected for the third term.", "In 1921 the Russians attacked and occupied the country and forcibly absorbed it into the Soviet state.", "The Caucasian war for independence restarted, and the government went into exile.===Soviet rule===During Soviet rule, Chechnya and Ingushetia were combined to form the Checheno-Ingush Autonomous Soviet Socialist Republic.", "In the 1930s, Chechnya was flooded with many Ukrainians fleeing a famine.", "As a result, many of the Ukrainians settled in Chechen-Ingush ASSR permanently and survived the famine.Although over 50,000 Chechens and over 12,000 Ingush were fighting against Nazi Germany on the front line (including Heroes of the USSR: Abukhadzhi Idrisov, Khanpasha Nuradilov, Movlid Visaitov), and although Nazi German troops advanced as far as the Ossetian ASSR city of Ordzhonikidze and the Chechen-Ingush ASSR city of Malgobek after capturing half of the Caucasus in less than a month, Chechens and Ingush were falsely accused as Nazi supporters and entire nations were deported during Operation Lentil to the Kazakh SSR (later Kazakhstan) in 1944 near the end of World War II where over 60% of Chechen and Ingush populations perished.", "American historian Norman Naimark writes:The deportation was justified by the materials prepared by NKVD officer Bogdan Kobulov accusing Chechens and Ingush in a mass conspiracy preparing rebellion and providing assistance to the German forces.", "Many of the materials were later proven to be fabricated.", "Even distinguished Red Army officers who fought bravely against Germans (e.g.", "the commander of 255th Separate Chechen-Ingush regiment Movlid Visaitov, the first to contact American forces at Elbe river) were deported.", "There is a theory that the real reason why Chechens and Ingush were deported was the desire of Russia to attack Turkey, an anti-communist country, as Chechens and Ingush could impede such plans.", "In 2004, the European Parliament recognized the deportation of Chechens and Ingush as an act of genocide.The territory of the Chechen-Ingush Autonomous Soviet Socialist Republic was divided between Stavropol Krai (where Grozny Okrug was formed), the Dagestan ASSR, the North Ossetian ASSR, and the Georgian SSR.The Chechens and Ingush were allowed to return to their land after 1956 during de-Stalinisation under Nikita Khrushchev when the Chechen-Ingush ASSR was restored but with both the boundaries and ethnic composition of the territory significantly changed.", "There were many (predominantly Russian) migrants from other parts of the Soviet Union, who often settled in the abandoned family homes of Chechens and Ingushes.", "The republic lost its Prigorodny District which transferred to North Ossetian ASSR but gained predominantly Russian Naursky District and Shelkovskoy District that is considered the homeland for Terek Cossacks.The Russification policies towards Chechens continued after 1956, with Russian language proficiency required in many aspects of life to provide Chechens better opportunities for advancement in the Soviet system.On 26 November 1990, the Supreme Council of Chechen-Ingush ASSR adopted the \"Declaration of State Sovereignty of the Chechen-Ingush Republic\".", "This declaration was part of the reorganisation of the Soviet Union.", "This new treaty was to be signed 22 August 1991, which would have transformed 15 republic states into more than 80.The 19–21 August 1991 Soviet coup d'état attempt led to the abandonment of this reorganisation.With the impending dissolution of the Soviet Union in 1991, an independence movement, the Chechen National Congress, was formed, led by ex-Soviet Air Force general and new Chechen President Dzhokhar Dudayev.", "It campaigned for the recognition of Chechnya as a separate nation.", "This movement was opposed by Boris Yeltsin's Russian Federation, which argued that Chechnya had not been an independent entity within the Soviet Union—as the Baltic, Central Asian, and other Caucasian states such as Georgia had—but was part of the Russian Soviet Federative Socialist Republic and hence did not have a right under the Soviet constitution to secede.", "It also argued that other republics of Russia, such as Tatarstan, would consider seceding from the Russian Federation if Chechnya were granted that right.", "Finally, it argued that Chechnya was a major hub in the oil infrastructure of Russia and hence its secession would hurt the country's economy and energy access.During the Chechen Revolution, the Soviet Chechen leader Doku Zavgayev was overthrown and Dzhokhar Dudayev seized power.", "On 1 November 1991, Dudaev's Chechnya issued a unilateral declaration of independence.", "In the ensuing decade, the territory was locked in an ongoing struggle between various factions, usually fighting unconventionally.===Chechen Wars and brief independence===Battle of Grozny.The First Chechen War took place from 1994 to 1996, when Russian forces attempted to regain control over Chechnya.", "Despite overwhelming numerical superiority in men, weaponry, and air support, the Russian forces were unable to establish effective permanent control over the mountainous area due to numerous successful full-scale battles and insurgency raids.", "The Budyonnovsk hospital hostage crisis in 1995 shocked the Russian public.Dzhokhar DudayevAslan MaskhadovIn April 1996 the first democratically elected president of Chechnya, Dzhokhar Dudayev, was killed by Russian forces using a booby trap bomb and a missile fired from a warplane after he was located by triangulating the position of a satellite phone he was using.The widespread demoralisation of the Russian forces in the area and a successful offensive to re-take Grozny by Chechen rebel forces led by Aslan Maskhadov prompted Russian President Boris Yeltsin to declare a ceasefire in 1996, and sign a peace treaty a year later that saw a withdrawal of Russian forces.After the war, parliamentary and presidential elections took place in January 1997 in Chechnya and brought to power new President Aslan Maskhadov, chief of staff and prime minister in the Chechen coalition government, for a five-year term.", "Maskhadov sought to maintain Chechen sovereignty while pressing the Russian government to help rebuild the republic, whose formal economy and infrastructure were virtually destroyed.", "Russia continued to send money for the rehabilitation of the republic; it also provided pensions and funds for schools and hospitals.", "Nearly half a million people (40% of Chechnya's prewar population) had been internally displaced and lived in refugee camps or overcrowded villages.", "There was an economic downturn.", "Two Russian brigades were permanently stationed in Chechnya.Cadets of the Ichkeria Chechen national guard 1999.In light of the devastated economic structure, kidnapping emerged as the principal source of income countrywide, procuring over US$200 million during the three-year independence of the chaotic fledgling state, although victims were rarely killed.", "In 1998, 176 people were kidnapped, 90 of whom were released, according to official accounts.", "President Maskhadov started a major campaign against hostage-takers, and on 25 October 1998, Shadid Bargishev, Chechnya's top anti-kidnapping official, was killed in a remote-controlled car bombing.", "Bargishev's colleagues then insisted they would not be intimidated by the attack and would go ahead with their offensive.", "Political violence and religious extremism, blamed on \"Wahhabism\", was rife.", "In 1998, Grozny authorities declared a state of emergency.", "Tensions led to open clashes between the Chechen National Guard and Islamist militants, such as the July 1998 confrontation in Gudermes.Chechen fighter stands near the government palace building during a short lull in fighting in Grozny, Chechnya.The War of Dagestan began on 7 August 1999, during which the Islamic International Peacekeeping Brigade (IIPB) began an unsuccessful incursion into the neighboring Russian republic of Dagestan in favor of the Shura of Dagestan which sought independence from Russia.", "In September, a series of apartment bombs that killed around 300 people in several Russian cities, including Moscow, were blamed on the Chechen separatists.", "Some journalists contested the official explanation, instead blaming the Russian Secret Service for blowing up the buildings to initiate a new military campaign against Chechnya.", "In response to the bombings, a prolonged air campaign of retaliatory strikes against the Ichkerian regime and a ground offensive that began in October 1999 marked the beginning of the Second Chechen War.", "Much better organized and planned than the First Chechen War, the Russian armed forces took control of most regions.", "The Russian forces used brutal force, killing 60 Chechen civilians during a mop-up operation in Aldy, Chechnya on 5 February 2000.After the re-capture of Grozny in February 2000, the Ichkerian regime fell apart.===Post-war reconstruction and insurgency===Postage stamp issued in 2009 by the Russian Post dedicated to ChechnyaMinutka Square, GroznyChechen rebels continued to fight Russian troops and conduct terrorist attacks.", "In October 2002, 40–50 Chechen rebels seized a Moscow theater and took about 900 civilians hostage.", "The crisis ended with 117 hostages and up to 50 rebels dead, mostly due to an unknown aerosol pumped into the building by Russian special forces to incapacitate the people inside.In response to the increasing terrorism, Russia tightened its grip on Chechnya and expanded its anti-terrorist operations throughout the region.", "Russia installed a pro-Russian Chechen regime.", "In 2003, a referendum was held on a constitution that reintegrated Chechnya within Russia but provided limited autonomy.", "According to the Chechen government, the referendum passed with 95.5% of the votes and almost 80% turnout.", "''The Economist'' was skeptical of the results, arguing that \"few outside the Kremlin regard the referendum as fair\".In September 2004, separatist rebels occupied a school in the town of Beslan, North Ossetia, demanding recognition of the independence of Chechnya and a Russian withdrawal.", "1,100 people (including 777 children) were taken hostage.", "The attack lasted three days, resulting in the deaths of over 331 people, including 186 children.", "After the 2004 school siege, Russian president Vladimir Putin announced sweeping security and political reforms, sealing borders in the Caucasus region and revealing plans to give the central government more power.", "He also vowed to take tougher action against domestic terrorism, including preemptive strikes against Chechen separatists.", "In 2005 and 2006, separatist leaders Aslan Maskhadov and Shamil Basayev were killed.Since 2007, Chechnya has been governed by Ramzan Kadyrov.", "Kadyrov's rule has been characterized by high-level corruption, a poor human rights record, widespread use of torture, and a growing cult of personality.", "Allegations of anti-gay purges in Chechnya were initially reported on 1 April 2017.In April 2009, Russia ended its counter-terrorism operation and pulled out the bulk of its army.", "The insurgency in the North Caucasus continued even after this date.", "The Caucasus Emirate had fully adopted the tenets of a Salafist jihadist group through its strict adherence to the Sunni Hanbali obedience to the literal interpretation of the Quran and the Sunnah.The Chechen government has been outspoken in its support for the 2022 Russian invasion of Ukraine, where a Chechen military force, the Kadyrovtsy, which is under Kadyrov's personal command, has played a leading role, notably in the Siege of Mariupol.", "Meanwhile, a substantial number of Chechen separatists have allied themselves to the Ukrainian cause and are fighting a mutual Russian enemy in the Donbas.", "In June 2022, the US State Department advised citizens not to travel to Chechnya, due to terrorism, kidnapping, and risk of civil unrest." ], [ "Geography", "The mountains in the area SharoyLake KezenoyamSituated in the eastern part of the North Caucasus in Eastern Europe, Chechnya is surrounded on nearly all sides by Russian Federal territory.", "In the west, it borders North Ossetia and Ingushetia, in the north, Stavropol Krai, in the east, Dagestan, and to the south, Georgia.", "Its capital is Grozny.", "Chechnya is well known for being mountainous, but it is in fact split between the more flat areas north of the Terek, and the highlands south of the Terek.", "*Area: 17,300 km2 (6680 sq mi)*Borders:**''Internal'':***Dagestan (NE)***Ingushetia (W)***North Ossetia–Alania (W)***Stavropol Krai (NW)**''Foreign'':***Georgia (Kakheti and Mtskheta-Mtianeti) (S)'''Rivers:'''*Terek*Sunzha*Argun===Climate===Despite a relatively small territory, Chechnya is characterized by a variety of climate conditions.", "The average temperature in Grozny is 11.2 °C (52.1 °F).===Cities and towns with over 20,000 people===Map of Chechen Republic (Chechnya)*Grozny (capital)*Shali*Urus-Martan*Gudermes*Argun*Kurchaloy*Achkoy-Martan" ], [ "Administrative divisions", "The Chechen Republic is divided into 15 districts and 3 cities of republican significance." ], [ "Demographics", "According to the 2021 Census, the population of the republic is 1,510,824, up from 1,268,989 in the 2010 Census.As of the 2021 Census, Chechens at 1,456,792 make up 96.4% of the republic's population.", "Other groups include Russians (18,225, or 1.2%), Kumyks (12,184, or 0.8%) and a host of other small groups, each accounting for less than 0.5% of the total population The birth rate was 25.41 in 2004.", "(25.7 in Achkhoi Martan, 19.8 in Groznyy, 17.5 in Kurchaloi, 28.3 in Urus Martan and 11.1 in Vedeno).The languages used in the Republic are Chechen and Russian.", "Chechen belongs to the Vaynakh or North-central Caucasian language family, which also includes Ingush and Batsb.", "Some scholars place it in a wider North Caucasian languages.Great Patriotic War===Life expectancy===Despite its difficult past, Chechnya has a high life expectancy, one of the highest in Russia.", "But the pattern of life expectancy is unusual, and in according to numerous statistics, Chechnya stands out from the overall picture.", "In 2020 Chechnya had the deepest fall in life expectancy, but in 2021 it had the biggest rise.", "Chechnya has the highest excess of life expectancy in rural areas over cities.20192021Average: 75.9 years 73.0 yearsMale: 73.6 years 70.5 yearsFemale: 78.0 years 75.3 yearsFile:Life expectancy in Russian subject -Chechnya.png|Life expectancy at birth in ChechnyaFile:Life expectancy in Russian subject -Chechnya -diff.png|Life expectancy with calculated differencesFile:Life expectancy in Russia -Chechnya.png|Life expectancy in Chechnya in comparison with neighboring regions of the countryFile:Comparison of life expectancy in Russian subjects by sex.svg|Interactive chart of comparison of male and female life expectancy for 2021.Open the original svg-file in a separate window and hover over a bubble to highlight it.File:Comparison of life expectancy in Russian subjects by type of settlement.svg|Analogious interactive chart of comparison of urban and rural life expectancy.", "Original interactive file.===Settlements======Vital statistics===Ethnolinguistic groups in the Caucasus region:Source: Fedstat (Суммарный коэффициент рождаемости) Average population (x 1000) Live births Deaths Natural change Crude birth rate (per 1000) Crude death rate (per 1000) Natural change (per 1000) Total fertility rate 2003 1,117 27,774 7,194 20 580 24.9 6.4 18.4 2004 1,133 28,496 6,347 22,149 25.2 5.6 19.5 2005 1,150 28,652 5,857 22,795 24.9 5.1 19.8 2006 1,167 27,989 5,889 22,100 24.0 5.0 18.9 2007 1,187 32,449 5,630 26,819 27.3 4.7 22.6 3.18 2008 1,210 35,897 5,447 30,450 29.7 4.5 25.2 3.44 2009 1,235 36,523 6,620 29,903 29.6 5.4 24.2 3.41 2010 1,260 37,753 7,042 30,711 30.0 5.6 24.4 3.45 2011 1,289 37,335 6,810 30,525 28.9 5.3 23.6 3.36 2012 1,314 34,385 7,192 27,193 26.2 5.5 20.7 3.08 2013 1,336 32,963 6,581 26,382 24.7 4.9 19.8 2.93 2014 1,358 32,949 6,864 26,085 24.3 5.1 19.2 2.91 2015 1,383 32,057 6,728 25,329 23.2 4.9 18.3 2.80 2016 1,404 29,893 6,630 23,263 21.3 4.7 16.6 2.62 2017 1,425 29,890 6,586 23,304 21.0 4.6 16.4 2.73 2018 1,444 29,883 6,430 23,453 20.6 4.4 16.2 2.60 2019 1,467 28,145 6,357 21,788 19.2 4.3 14.9 2.58 2020 1,488 30,111 9,188 20,923 20.2 6.2 14.0 2.57 2021 1,509 30,345 8,904 21,441 20.1 5.9 14.2 2.50 2022 30,821 7,370 23,451 20.2 4.8 15.4 2.74===Ethnic groups===(in the territory of modern Chechnya) Ethnicgroup 1926 Census 1939 Census2 1959 Census2 1970 Census 1979 Census 1989 Census 2002 Census 2010 Census 2021 Census1 Number% Number% Number% Number% Number% Number% Number% Number% Number% Chechens 293,298 67.3% 360,889 58.0% 238,331 39.7% 499,962 54.7% 602,223 60.1% 715,306 66.0% 1,031,647 93.5% 1,206,551 95.3% 1,456,792 96.4% Russians 103,271 23.5% 213,354 34.3% 296,794 49.4% 327,701 35.8% 307,079 30.6% 269,130 24.8% 40,645 3.7% 24,382 1.9% 18,225 1.2% Kumyks 2,217 0.5% 3,575 0.6% 6,865 0.8% 7,808 0.8% 9,591 0.9% 8,883 0.8% 12,221 1.0% 12,184 0.8% Avars 830 0.2% 2,906 0.5% 4,196 0.5% 4,793 0.5% 6,035 0.6% 4,133 0.4% 4,864 0.4% 4,079 0.3% Nogais 162 0.0% 1,302 0.2% 5,503 0.6% 6,079 0.6% 6,885 0.6% 3,572 0.3% 3,444 0.3% 2,819 0.2% Ingush 798 0.2% 4,338 0.7% 3,639 0.6% 14,543 1.6% 20,855 2.1% 25,136 2.3% 2,914 0.3% 1,296 0.1% 1,100 0.1% Ukrainians 11,474 2.6% 8,614 1.4% 11,947 2.0% 11,608 1.3% 11,334 1.1% 11,884 1.1% 829 0.1% 13,716 1.1% 15,625 1.0% Armenians 5,978 1.4% 8,396 1.3% 12,136 2.0% 13,948 1.5% 14,438 1.4% 14,666 1.4% 424 0.0% Others 18,840 4.13% 18,646 3.0% 37,550 6.3% 30,057 3.3% 27,621 2.8% 25,800 2.4% 10,639 1.0% 1 2,515 people were registered from administrative databases, and could not declare an ethnicity.", "It is estimated that the proportion of ethnicities in this group is the same as that of the declared group.2 Practically all Chechen and Ingush people were deported to Central Asia in 1944.They were, however, allowed to return to the Northern Caucasus in 1957 by Nikita Khrushchev.", "See Deportation of the Chechens and Ingush===Religion=======Islam====The Heart of Chechnya MosqueSunni Islam is the predominant religion in Chechnya, practiced by 95% of those polled in Grozny in 2010.Most of the population is Sunni and follows either the Shafi'i or the Hanafi schools of fiqh (Islamic jurisprudence).", "The Shafi'i school of jurisprudence has a long tradition among the Chechens, and thus it remains the most practiced.", "Many Chechens are also Sufis, of either the Qadiri or Naqshbandi orders.Following the end of the Soviet Union, there has been an Islamic revival in Chechnya, and in 2011 it was estimated that there were 465 mosques, including the Akhmad Kadyrov Mosque in Grozny accommodating 10,000 worshippers, as well 31 madrasas, including an Islamic university named Kunta-haji, the Kurchaloy Islamic Institute named Akhmad Kadyrov, and a Center of Islamic Medicine in Grozny which is the largest such institution in Europe.", "A supreme Islamic administrative territorial organisation in Chechnya is the Spiritual Administration of the Muslims of the Chechen Republic or the Muftiate of the Chechen Republic.====Christianity====From the 11th to 13th centuries (i.e.", "before Mongol invasions of Durdzuketia), there was a mission of Georgian Orthodox missionaries to the Nakh peoples.", "Their success was limited, though a couple of highland teips did convert (conversion was largely by teips).", "However, during the Mongol invasions, these Christianized teips gradually reverted to paganism, perhaps due to the loss of trans-Caucasian contacts as the Georgians fought the Mongols and briefly fell under their dominion.The once-strong Russian minority in Chechnya, mostly Terek Cossacks and estimated as numbering approximately 25,000 in 2012, are predominantly Russian Orthodox, although currently only one church exists in Grozny.", "In August 2011, Archbishop Zosima of Vladikavkaz and Makhachkala performed the first mass baptism ceremony in the history of the Chechen Republic in the Terek River of Naursky District in which 35 citizens of Naursky and Shelkovsky districts were converted to Orthodoxy.", "As of 2020, there are eight Orthodox churches in Chechnya, the largest is the temple of the Archangel Michael in Grozny." ], [ "Politics", "Since 1990, the Chechen Republic has had many legal, military, and civil conflicts involving separatist movements and pro-Russian authorities.", "Today, Chechnya is a relatively stable federal republic, although there is still some separatist movement activity.", "Its regional constitution entered into effect on 2 April 2003, after an all-Chechen referendum was held on 23 March 2003.Some Chechens were controlled by regional teips, or clans, despite the existence of pro- and anti-Russian political structures.===Regional government===Akhmad Kadyrov, former separatist and head of the Chechen Republic, with Russian President Vladimir PutinThe former separatist religious leader (mufti) Akhmad Kadyrov, looked upon as a traitor by many separatists, was elected president with 83% of the vote in an internationally monitored election on 5th of October 2003.Incidents of ballot stuffing and voter intimidation by Russian soldiers and the exclusion of separatist parties from the polls were subsequently reported by Organization for Security and Co-operation in Europe (OSCE) monitors.", "On 9 May 2004, Kadyrov was assassinated in Grozny football stadium by a landmine explosion that was planted beneath a VIP stage and detonated during a parade, and Sergey Abramov was appointed acting prime minister after the incident.", "However, since 2005 Ramzan Kadyrov (son of Akhmad Kadyrov) has been the caretaker prime minister, and in 2007 was appointed as the new president.", "Many allege he is the wealthiest and most powerful man in the republic, with control over a large private militia (the Kadyrovites).", "The militia, which began as his father's security force, has been accused of killings and kidnappings by human rights organisations such as Human Rights Watch.===Separatist government===Ichkeria was a member of the Unrepresented Nations and Peoples Organisation between 1991 and 2010.Former president of Georgia Zviad Gamsakhurdia deposed in a military coup of 1991 and a participant of the Georgian Civil War, recognized the independence of the Chechen Republic of Ichkeria in 1993.Diplomatic relations with Ichkeria were also established by the partially recognised Islamic Emirate of Afghanistan under the Taliban government on 16 January 2000.This recognition ceased with the fall of the Taliban in 2001.However, despite Taliban recognition, there were no friendly relations between the Taliban and Ichkeria—Maskhadov rejected their recognition, stating that the Taliban were illegitimate.", "Ichkeria also received vocal support from the Baltic countries, a group of Ukrainian nationalists, and Poland; Estonia once voted to recognize, but the act never was followed through due to pressure applied by both Russia and the EU.Shamil Basayev, Chechen militant Islamist and a leader of the Chechen rebel movementThe president of this government was Aslan Maskhadov, and the foreign minister was Ilyas Akhmadov, who was the spokesman for the president.", "Maskhadov had been elected for four years in an internationally monitored election in 1997, which took place after signing a peace agreement with Russia.", "In 2001 he issued a decree prolonging his office for one additional year; he was unable to participate in the 2003 presidential election since separatist parties were barred by the Russian government, and Maskhadov faced accusations of terrorist offenses in Russia.", "Maskhadov left Grozny and moved to the separatist-controlled areas of the south at the onset of the Second Chechen War.", "Maskhadov was unable to influence a number of warlords who retain effective control over Chechen territory, and his power was diminished as a result.", "Russian forces killed Maskhadov on 8 March 2005, and the assassination was widely criticized since it left no legitimate Chechen separatist leader with whom to conduct peace talks.", "Akhmed Zakayev, deputy prime minister and a foreign minister under Maskhadov, was appointed shortly after the 1997 election and is currently living under asylum in England.", "He and others chose Abdul Khalim Saidullayev, a relatively unknown Islamic judge who was previously the host of an Islamic program on Chechen television, to replace Maskhadov following his death.", "On 17 June 2006, it was reported that Russian special forces killed Abdul Khalim Saidullayev in a raid in the Chechen town of Argun.", "On 10 July 2006, Shamil Basayev, a leader of the Chechen rebel movement, was killed in a truck explosion during an arms deal.The successor of Saidullayev became Doku Umarov.", "On 31 October 2007, Umarov abolished the Chechen Republic of Ichkeria and its presidency and in its place proclaimed the Caucasus Emirate with himself as its Emir.", "This change of status has been rejected by many Chechen politicians and military leaders who continue to support the existence of the republic.During the 2022 Russian invasion of Ukraine, the Ukrainian parliament voted to recognize the \"Chechen Republic of Ichkeria as territory temporarily occupied by the Russian Federation\"." ], [ "Human rights", "Тhe Internal Displacement Monitoring Center reports that after hundreds of thousands of ethnic Russians and Chechens fled their homes following inter-ethnic and separatist conflicts in Chechnya in 1994 and 1999, more than 150,000 people still remain displaced in Russia today.Нuman rights groups criticized the conduct of the 2005 parliamentary elections as unfairly influenced by the central Russian government and military.In 2006 Human Rights Watch reported that pro-Russian Chechen forces under the command of Ramzan Kadyrov, as well as federal police personnel, used torture to get information about separatist forces.", "\"If you are detained in Chechnya, you face a real and immediate risk of torture.", "And there is little chance that your torturer will be held accountable\", said Holly Cartner, Director of the Europe and Central Asia division of the Human Rights Watch.Chechen leader Ramzan Kadyrov in 2018In 2009, the US government financed American organization Freedom House included Chechnya in the \"Worst of the Worst\" list of most repressive societies in the world, together with Burma, North Korea, Tibet, and others.", "Memorial considers Chechnya under Kadyrov to be a totalitarian regime.On 1 February 2009, ''The New York Times'' released extensive evidence to support allegations of consistent torture and executions under the Kadyrov government.", "The accusations were sparked by the assassination in Austria of a former Chechen rebel who had gained access to Kadyrov's inner circle, 27-year-old Umar Israilov.On 1 July 2009, Amnesty International released a detailed report covering the human rights violations committed by the Russian Federation against Chechen citizens.", "Among the most prominent features was that those abused had no method of redress against assaults, ranging from kidnapping to torture, while those responsible were never held accountable.", "This led to the conclusion that Chechnya was being ruled without law, being run into further devastating destabilization.On 10 March 2011, Human Rights Watch reported that since Chechenization, the government has pushed for enforced Islamic dress code.", "The president Ramzan Kadyrov is quoted as saying \"I have the right to criticize my wife.", "She doesn't have the right to criticize me.", "With us in Chechen society, a wife is a housewife.", "A woman should know her place.", "A woman should give her love to us men... She would be man's property.", "And the man is the owner.", "Here, if a woman does not behave properly, her husband, father, and brother are responsible.", "According to our tradition, if a woman fools around, her family members kill her... That's how it happens, a brother kills his sister or a husband kills his wife... As a president, I cannot allow for them to kill.", "So, let women not wear shorts...\".", "He has also openly defended honor killings on several occasions.On 9 July 2017, Russian newspaper reported that a number of people were subject to an extrajudicial execution on the night of 26 January 2017.It published 27 names of the people known to be dead, but stressed that the list is \"not all of those killed\"; the newspaper asserted that 50 people may have been killed in the execution.", "Some of the dead were gay, but not all; the deaths appeared to have been triggered by the death of a policeman, and according to the author of the report, Elena Milashina, were executed for alleged terrorism.In December 2021, up to 50 family members of critics of the Kadyrov government were abducted in a wave of mass kidnappings beginning on 22 December.===LGBT rights===Although homosexuality is officially legal in Chechnya per Russian law, it is ''de facto'' illegal.", "Chechen authorities have reportedly arrested, imprisoned and killed persons based on their perceived sexual orientation.In 2017, it was reported by and human rights groups that Chechen authorities had set up concentration camps, one of which is in Argun, where gay men are interrogated and subjected to physical violence.", "On 27 June 2018, the Parliamentary Assembly of the Council of Europe noted \"cases of abduction, arbitrary detention and torture ... with the direct involvement of Chechen law enforcement officials and on the orders of top-level Chechen authorities\" and expressed dismay \"at the statements of Chechen and Russian public officials denying the existence of LGBTI people in the Chechen Republic\".", "Kadyrov's spokesman Alvi Karimov told Interfax that gay people \"simply do not exist in the republic\" and made an approving reference to honor killings by family members \"if there were such people in Chechnya\".", "In a 2021 Council of Europe report into anti-LGBTI hate crimes, rapporteur Foura ben Chikha described the \"state-sponsored attacks carried out against LGBTI people in Chechnya in 2017\" as \"the single most egregious example of violence against LGBTI people in Europe that has occurred in decades\".On 11 January 2019, it was reported that another 'gay purge' had begun in the country in December 2018, with several gay men and women being detained.", "The Russian LGBT Network believes that around 40 people were detained and two killed." ], [ "Economy", "Grozny in 2013, with the \"Heart of Chechnya\" Mosque on the rightDuring the war, the Chechen economy fell apart.", "In 1994, the separatists planned to introduce a new currency, but the change did not occur due to the re-taking of Chechnya by Russian troops in the Second Chechen War.The economic situation in Chechnya has improved considerably since 2000.According to the ''New York Times'', major efforts to rebuild Grozny have been made, and improvements in the political situation have led some officials to consider setting up a tourism industry, though there are claims that construction workers are being irregularly paid and that poor people have been displaced.Chechnya's unemployment was 67% in 2006 and fell to 21.5% in 2014.Total revenue of the budget of Chechnya for 2017 was 59.2 billion rubles.", "Of these, 48.5 billion rubles were grants from the federal budget of the Russian Federation.In late 1970s, Chechnya produced up to 20 million tons of oil annually, production declined sharply to approximately 3 million tons in the late 1980s, and to below 2 million tons before 1994, first (1994–1996) second Russian invasion of Chechnya (1999) inflicted material damage on the oil-sector infrastructure, oil production decreased to 750,000 tons in 2001 only to increase to 2 million tons in 2006, by 2012 production was 1 million tons." ], [ "Culture", "The culture of Chechnya is based on the native traditions of Chechen people.", "Chechen mythology along with art have helped shape the culture for over 1,000 years." ], [ "References", "=== Notes ====== Sources ===* * * *" ], [ "Further reading", "*Anderson, Scott.", "The Man Who Tried to Save the World.", "*Babchenko, Arkady.", "''One Soldier's War in Chechnya''.", "Portobello, London *Baiev, Khassan.", "''The Oath: A Surgeon Under Fire''.", "*Bennigsen-Broxup, Marie.", "''The North Caucasus Barrier: The Russian Advance Towards the Muslim World''.", "*Bird, Chris.", "''To Catch a Tartar: Notes from the Caucasus''.", "*Bornstein, Yvonne and Ribowsky, Mark.", "\"Eleven Days of Hell: My True Story of Kidnapping, Terror, Torture And Historic FBI & KGB Rescue\" AuthorHouse, 2004..*Conrad, Roy.", "Roy Conrad.", "Grozny.", "A few days...*Dunlop, John B.", "''Russia Confronts Chechnya: Roots of a Separatist Conflict'' *Evangelista, Mathew.", "''The Chechen Wars: Will Russia Go the Way of the Soviet Union?''.", ".", "*Gall, Charlotta & de Waal, Thomas.", "''Chechnya: A Small Victorious War''.", "*Gall, Carlotta, and de Waal, Thomas ''Chechnya: Calamity in the Caucasus'' *Goltz, Thomas.", "''Chechnya Diary : A War Correspondent's Story of Surviving the War in Chechnya''.", "M E Sharpe (2003).", "*Hasanov, Zaur.", "The Man of the Mountains.", "(facts based novel on growing influence of the radical Islam during 1st and 2nd Chechnya wars)*Khan, Ali.", "The Chechen Terror: The Play within the Play*Khlebnikov, Paul.", "''Razgovor s varvarom'' (Interview with a barbarian).", ".", "*Lieven, Anatol.", "''Chechnya : Tombstone of Russian Power'' *Mironov, Vyacheslav.", "''Ya byl na etoy voyne.''", "(I was in this war) Biblion – Russkaya Kniga, 2001.Partial translation available online.", "*Mironov, Vyacheslav.", "Vyacheslav Mironov.", "Assault on Grozny Downtown*Mironov, Vyacheslav.", "Vyacheslav Mironov.", "''I was in that war''.", "*Oliker, Olga ''Russia's Chechen Wars 1994–2000: Lessons from Urban Combat''.", ".", "(A strategic and tactical analysis of the Chechen Wars.", ")*Pelton, Robert Young.", "''Hunter Hammer and Heaven, Journeys to Three World's Gone Mad'' ()*Politkovskaya, Anna.", "''A Small Corner of Hell: Dispatches from Chechnya'' *Rasizade, Alec.", "Chechnya: the Achilles heel of Russia.", "= Contemporary Review (Oxford) in three parts: 1) April 2005 issue, volume 286, number 1671, pages 193–197; 2) May 2005 issue, volume 286, number 1672, pages 277–284; 3) June 2005 issue, volume 286, number 1673, pages 327–332.", "*Seirstad, Asne.", "The Angel of Grozny.", "*Wood, Tony.", "Chechnya: The Case For Independence Book review in The Independent, 2007" ], [ "External links", "* of the Republic of Chechnya *** (video)* Islamist Extremism in Chechnya: A Threat to U.S.", "Homeland?", ": Joint Hearing before the Subcommittee on Europe, Eurasia, and Emerging Threats and the Subcommittee on Terrorism, Nonproliferation, and Trade of the Committee on Foreign Affairs, House of Representatives, One Hundred Thirteenth Congress, First Session, April 26, 2013* Chechnya Guide" ] ]
wikipedia
[ [ "Canonization" ], [ "Introduction", "St. Cyprian of Carthage, who urged diligence in the process of canonization'''Canonization''' is the declaration of a deceased person as an officially recognized saint, specifically, the official act of a Christian communion declaring a person worthy of public veneration and entering their name in the canon catalogue of saints, or authorized list of that communion's recognized saints." ], [ "Catholic Church", "Canonization of Elizabeth of Hungary in 1235.", "''Sándor Liezen-Mayer'' (1863).Canonization is a papal declaration that the Catholic faithful may venerate a particular deceased member of the church.", "Popes began making such decrees in the tenth century.", "Up to that point, the local bishops governed the veneration of holy men and women within their own dioceses; and there may have been, for any particular saint, no formal decree at all.", "In subsequent centuries, the procedures became increasingly regularized and the Popes began restricting to themselves the right to declare someone a Catholic saint.", "In contemporary usage, the term is understood to refer to the act by which any Christian church declares that a person who has died is a saint, upon which declaration the person is included in the list of recognized saints, called the \"canon\".=== Biblical roots ===In the Roman Martyrology, the following entry is given for the Penitent Thief: \"At Jerusalem, the commemoration of the good Thief, who confessed Christ on the cross, and deserved to hear from Him these words: 'This day thou shalt be with Me in paradise.", "'=== Historical development ===The Roman Rite's Canon of the Mass contains only the names of apostles and martyrs, along with that of the Blessed Virgin Mary and, since 1962, that of Saint Joseph her spouse.By the fourth century, however, \"confessors\"—people who had confessed their faith not by dying but by word and life—began to be venerated publicly.", "Examples of such people are Saint Hilarion and Saint Ephrem the Syrian in the East, and Saint Martin of Tours and Saint Hilary of Poitiers in the West.", "Their names were inserted in the diptychs, the lists of saints explicitly venerated in the liturgy, and their tombs were honoured in like manner as those of the martyrs.", "Since the witness of their lives was not as unequivocal as that of the martyrs, they were venerated publicly only with the approval by the local bishop.", "This process is often referred to as \"local canonization\".This approval was required even for veneration of a reputed martyr.", "In his history of the Donatist heresy, Saint Optatus recounts that at Carthage a Catholic matron, named Lucilla, incurred the censures of the Church for having kissed the relics of a reputed martyr whose claims to martyrdom had not been juridically proved.", "And Saint Cyprian (died 258) recommended that the utmost diligence be observed in investigating the claims of those who were said to have died for the faith.", "All the circumstances accompanying the martyrdom were to be inquired into; the faith of those who suffered, and the motives that animated them were to be rigorously examined, in order to prevent the recognition of undeserving persons.", "Evidence was sought from the court records of the trials or from people who had been present at the trials.Augustine of Hippo (died 430) tells of the procedure which was followed in his day for the recognition of a martyr.", "The bishop of the diocese in which the martyrdom took place set up a canonical process for conducting the inquiry with the utmost severity.", "The acts of the process were sent either to the metropolitan or primate, who carefully examined the cause, and, after consultation with the suffragan bishops, declared whether the deceased was worthy of the name of \"martyr\" and public veneration.Though not \"canonizations\" in the narrow sense, acts of formal recognition, such as the erection of an altar over the saint's tomb or transferring the saint's relics to a church, were preceded by formal inquiries into the sanctity of the person's life and the miracles attributed to that person's intercession.Such acts of recognition of a saint were authoritative, in the strict sense, only for the diocese or ecclesiastical province for which they were issued, but with the spread of the fame of a saint, were often accepted elsewhere also.=== Nature ===In the Catholic Church, both in the Latin and the constituent Eastern churches, the act of canonization is reserved to the Apostolic See and occurs at the conclusion of a long process requiring extensive proof that the candidate for canonization lived and died in such an exemplary and holy way that they are worthy to be recognized as a saint.", "The Church's official recognition of sanctity implies that the person is now in Heaven and that they may be publicly invoked and mentioned officially in the liturgy of the Church, including in the Litany of the Saints.In the Catholic Church, canonization is a decree that allows universal veneration of the saint.", "For permission to venerate merely locally, only beatification is needed.=== Procedure prior to reservation to the Apostolic See ===Pope Pius II canonizes Catherine of Siena.For several centuries the bishops, or in some places only the primates and patriarchs, could grant martyrs and confessors public ecclesiastical honor; such honor, however, was always decreed only for the local territory of which the grantors had jurisdiction.", "Only acceptance of the ''cultus'' by the Pope made the ''cultus'' universal, because he alone can rule the universal Catholic Church.", "Abuses, however, crept into this discipline, due as well to indiscretions of popular fervor as to the negligence of some bishops in inquiring into the lives of those whom they permitted to be honoured as saints.In the Medieval West, the Apostolic See was asked to intervene in the question of canonizations so as to ensure more authoritative decisions.", "The canonization of Saint Udalric, Bishop of Augsburg by Pope John XV in 993 was the first undoubted example of papal canonization of a saint from outside of Rome being declared worthy of liturgical veneration for the entire church.", "Thereafter, recourse to the judgment of the Pope occurred more frequently.", "Toward the end of the 11th century, the Popes began asserting their exclusive right to authorize the veneration of a saint against the older rights of bishops to do so for their dioceses and regions.", "Popes therefore decreed that the virtues and miracles of persons proposed for public veneration should be examined in councils, more specifically in general councils.", "Pope Urban II, Pope Calixtus II, and Pope Eugene III conformed to this discipline.=== Exclusive reservation to the Apostolic See ===Hugh de Boves, Archbishop of Rouen, canonized Walter of Pontoise, or St. Gaultier, in 1153, the final saint in Western Europe to be canonized by an authority other than the Pope: \"The last case of canonization by a metropolitan is said to have been that of St. Gaultier, or Gaucher, Abbot of Pontoise, by the Archbishop of Rouen.", "A decree of Pope Alexander III in 1170 gave the prerogative to the Pope thenceforth, so far as the Western Church was concerned.\"", "In a decretal of 1173, Pope Alexander III reprimanded some bishops for permitting veneration of a man who was merely killed while intoxicated, prohibited veneration of the man, and most significantly decreed that \"you shall not therefore presume to honor him in the future; for, even if miracles were worked through him, it is not lawful for you to venerate him as a saint without the authority of the Catholic Church.\"", "Theologians disagree as to the full import of the decretal of Pope Alexander III: either a new law was instituted, in which case the Pope then for the first time reserved the right of beatification to himself, or an existing law was confirmed.However, the procedure initiated by the decretal of Pope Alexander III was confirmed by a bull of Pope Innocent III issued on the occasion of the canonization of Cunigunde of Luxembourg in 1200.The bull of Pope Innocent III resulted in increasingly elaborate inquiries to the Apostolic See concerning canonizations.", "Because the decretal of Pope Alexander III did not end all controversy and some bishops did not obey it in so far as it regarded beatification, the right of which they had certainly possessed hitherto, Pope Urban VIII issued the Apostolic letter ''Caelestis Hierusalem cives'' of 5 July 1634 that exclusively reserved to the Apostolic See both its immemorial right of canonization and that of beatification.", "He further regulated both of these acts by issuing his ''Decreta servanda in beatificatione et canonizatione Sanctorum'' on 12 March 1642.=== Procedure from 1734 to 1738 to 1983 ===In his ''De Servorum Dei beatificatione et de Beatorum canonizatione'' of five volumes the eminent canonist Prospero Lambertini (1675–1758), who later became Pope Benedict XIV, elaborated on the procedural norms of Pope Urban VIII's Apostolic letter ''Caelestis Hierusalem cives'' of 1634 and ''Decreta servanda in beatificatione et canonizatione Sanctorum'' of 1642, and on the conventional practice of the time.", "His work published from 1734 to 1738 governed the proceedings until 1917.The article \"Beatification and canonization process in 1914\" describes the procedures followed until the promulgation of the ''Codex'' of 1917.The substance of ''De Servorum Dei beatifιcatione et de Beatorum canonizatione'' was incorporated into the ''Codex Iuris Canonici'' (''Code of Canon Law'') of 1917, which governed until the promulgation of the revised ''Codex Iuris Canonici'' in 1983 by Pope John Paul II.", "Prior to promulgation of the revised ''Codex'' in 1983, Pope Paul VI initiated a simplification of the procedures.=== Since 1983 ===The Apostolic constitution ''Divinus Perfectionis Magister'' of Pope John Paul II of 25 January 1983 and the norms issued by the Congregation for the Causes of Saints on 7 February 1983 to implement the constitution in dioceses, continued the simplification of the process initiated by Pope Paul VI.", "Contrary to popular belief, the reforms did not eliminate the office of the Promoter of the Faith (Latin: ''Promotor Fidei''), popularly known as the Devil's advocate, whose office is to question the material presented in favor of canonization.", "The reforms were intended to reduce the adversarial nature of the process.", "In November 2012 Pope Benedict XVI appointed Monsignor Carmello Pellegrino as Promoter of the Faith.Candidates for canonization undergo the following process:Canonization is a statement of the Church that the person certainly enjoys the beatific vision of Heaven.", "The title of \"Saint\" (Latin: ''Sanctus'' or ''Sancta'') is then proper, reflecting that the saint is a refulgence of the holiness (''sanctitas'') of God himself, which alone comes from God's gift.", "The saint is assigned a feast day which may be celebrated anywhere in the universal Church, although it is not necessarily added to the General Roman Calendar or local calendars as an \"obligatory\" feast; parish churches may be erected in their honor; and the faithful may freely celebrate and honor the saint.Although recognition of sainthood by the Pope does not directly concern a fact of Divine revelation, nonetheless it must be \"definitively held\" by the faithful as ''infallible'' pursuant to, at the least, the Universal Magisterium of the Church, because it is a truth related to revelation by historical necessity.=== Equipollent canonization ===Popes have several times permitted to the universal Church, without executing the ordinary judicial process of canonization described above, the veneration as a saint, the \"''cultus''\" of one long venerated as such locally.", "This act of a Pope is denominated \"equipollent\" or \"equivalent canonization\" and \"confirmation of ''cultus''\".", "In such cases, there is no need to have a miracle attributed to the saint to allow their canonization.", "According to the rules Pope Benedict XIV (''regnat'' 17 August 1740 – 3 May 1758) instituted, there are three conditions for an equipollent canonization: (1) existence of an ancient ''cultus'' of the person, (2) a general and constant attestation to the virtues or martyrdom of the person by credible historians, and (3) uninterrupted fame of the person as a worker of miracles." ], [ "Protestant denominations", "The majority of Protestant denominations do not formally recognize saints because the Bible uses the term in a way that suggests all Christians are saints.", "However, some denominations do, as shown below.=== Anglican Communion ===The Church of England, the Mother Church of the Anglican Communion, canonized Charles I as a saint, in the Convocations of Canterbury and York of 1660.=== United Methodist Church ===The General Conference of the United Methodist Church has formally declared individuals ''martyrs'', including Dietrich Bonhoeffer (in 2008) and Martin Luther King Jr. (in 2012)." ], [ "Eastern Orthodox Church<!--linked from 'Glorification'-->", "atrocities in Bulgaria (1876).", "On 3 April 2011, Batak massacre victims were canonized as saints.On 4 November 1992, the Holy Synod of the Church of Greece unanimously declared saints those Christians who had been tortured and massacred by the Turks in the Great fire of Smyrna in 1922.Various terms are used for canonization by the autocephalous Eastern Orthodox Churches: канонизация (\"canonization\") or прославление (\"glorification\", in the Russian Orthodox Church), კანონიზაცია (''kanonizats’ia'', Georgian Orthodox Church), канонизација (Serbian Orthodox Church), ''canonizare'' (Romanian Orthodox Church), and Канонизация (Bulgarian Orthodox Church).", "Additional terms are used for canonization by other autocephalous Eastern Orthodox Churches: (Katharevousa: ) ''agiokatataxi/agiokatataxis'', \"ranking among saints\" (Ecumenical Patriarchate of Constantinople, Church of Cyprus, Church of Greece), ''kanonizim'' (Albanian Orthodox Church), ''kanonizacja'' (Polish Orthodox Church), and ''kanonizace/kanonizácia'' (Czech and Slovak Orthodox Church).The Orthodox Church in America, an Eastern Orthodox Church partly recognized as autocephalous, uses the term \"glorification\" for the official recognition of a person as a saint." ], [ "Oriental Orthodox Church", "Within the Armenian Apostolic Church, part of Oriental Orthodoxy, there had been discussions since the 1980s about canonizing the victims of the Armenian genocide.", "On 23 April 2015, all of the victims of the genocide were canonized." ], [ "See also", "* List of canonizations* List of saints* List of early Christian saints* Decanonization" ], [ "Notes" ], [ "References", "*" ], [ "External links", "* ===Catholic Church===* ''Divinus Perfectionis Magister'' – Apostolic Constitution of Pope John Paul II (English)* Congregation for the Causes of Saints – Vatican Website* Historical Sketch of Canonization – Friarsminor.org" ] ]
wikipedia
[ [ "Carboxylic acid" ], [ "Introduction", "Structure of a carboxylic acidCarboxylate anion3D structure of a carboxylic acidIn organic chemistry, a '''carboxylic acid''' is an organic acid that contains a '''carboxyl group''' () attached to an R-group.", "The general formula of a carboxylic acid is often written as '''''' or '''''', sometimes as with R referring to the alkyl, alkenyl, aryl, or other group.", "Carboxylic acids occur widely.", "Important examples include the amino acids and fatty acids.", "Deprotonation of a carboxylic acid gives a carboxylate anion." ], [ "Examples and nomenclature", "Carboxylic acids are commonly identified by their trivial names.", "They often have the suffix ''-ic acid''.", "IUPAC-recommended names also exist; in this system, carboxylic acids have an ''-oic acid'' suffix.", "For example, butyric acid () is butanoic acid by IUPAC guidelines.", "For nomenclature of complex molecules containing a carboxylic acid, the carboxyl can be considered position one of the parent chain even if there are other substituents, such as 3-chloropropanoic acid.", "Alternately, it can be named as a \"carboxy\" or \"carboxylic acid\" substituent on another parent structure, such as 2-carboxyfuran.The carboxylate anion ( or ) of a carboxylic acid is usually named with the suffix ''-ate'', in keeping with the general pattern of ''-ic acid'' and ''-ate'' for a conjugate acid and its conjugate base, respectively.", "For example, the conjugate base of acetic acid is acetate.Carbonic acid, which occurs in bicarbonate buffer systems in nature, is not generally classed as one of the carboxylic acids, despite that it has a moiety that looks like a COOH group.", "+Straight-chain, saturated carboxylic acids (alkanoic acids)CarbonatomsCommon NameIUPAC NameChemical formulaCommon location or use1 Formic acid Methanoic acid HCOOH Insect stings2 Acetic acid Ethanoic acid Vinegar3 Propionic acid Propanoic acid Preservative for stored grains, body odour, milk, butter, cheese4 Butyric acid Butanoic acid Butter5 Valeric acid Pentanoic acid Valerian plant6 Caproic acid Hexanoic acid Goat fat7 Enanthic acid Heptanoic acid Fragrance8 Caprylic acid Octanoic acid Coconuts9 Pelargonic acid Nonanoic acid Pelargonium plant10 Capric acid Decanoic acid Coconut and Palm kernel oil11 Undecylic acid Undecanoic acid Anti-fungal agent12 Lauric acid Dodecanoic acid Coconut oil and hand wash soaps13 Tridecylic acid Tridecanoic acid Plant metabolite14 Myristic acid Tetradecanoic acid Nutmeg15 Pentadecylic acid Pentadecanoic acid Milk fat16 Palmitic acid Hexadecanoic acid Palm oil17 Margaric acid Heptadecanoic acid Pheromone in various animals18 Stearic acid Octadecanoic acid Chocolate, waxes, soaps, and oils19 Nonadecylic acid Nonadecanoic acid Fats, vegetable oils, pheromone 20 Arachidic acid Icosanoic acid Peanut oil+ Other carboxylic acids Compound class Membersunsaturated monocarboxylic acids acrylic acid (2-propenoic acid) – , used in polymer synthesis Fatty acids medium to long-chain saturated and unsaturated monocarboxylic acids, with even number of carbons; examples: docosahexaenoic acid and eicosapentaenoic acid (nutritional supplements) Amino acids the building-blocks of proteins Keto acids acids of biochemical significance that contain a ketone group; examples: acetoacetic acid and pyruvic acid Aromatic carboxylic acids containing at least one aromatic ring; examples: benzoic acid – the sodium salt of benzoic acid is used as a food preservative; salicylic acid – a beta-hydroxy type found in many skin-care products; phenyl alkanoic acids – the class of compounds where a phenyl group is attached to a carboxylic acid Dicarboxylic acids containing two carboxyl groups; examples: adipic acid the monomer used to produce nylon and aldaric acid – a family of sugar acids Tricarboxylic acids containing three carboxyl groups; examples: citric acid – found in citrus fruits and isocitric acid Alpha hydroxy acids containing a hydroxy group in the first position; examples: glyceric acid, glycolic acid and lactic acid (2-hydroxypropanoic acid) – found in sour milk, tartaric acid – found in wine Beta hydroxy acids containing a hydroxy group in the second position Omega hydroxy acids containing a hydroxy group beyond the first or second position Divinylether fatty acids containing a doubly unsaturated carbon chain attached via an ether bond to a fatty acid, found in some plants" ], [ "Physical properties", "===Solubility===Carboxylic acids are polar.", "Because they are both hydrogen-bond acceptors (the carbonyl ) and hydrogen-bond donors (the hydroxyl ), they also participate in hydrogen bonding.", "Together, the hydroxyl and carbonyl group form the functional group carboxyl.", "Carboxylic acids usually exist as dimers in nonpolar media due to their tendency to \"self-associate\".", "Smaller carboxylic acids (1 to 5 carbons) are soluble in water, whereas bigger carboxylic acids have limited solubility due to the increasing hydrophobic nature of the alkyl chain.", "These longer chain acids tend to be soluble in less-polar solvents such as ethers and alcohols.", "Aqueous sodium hydroxide and carboxylic acids, even hydrophobic ones, react to yield water-soluble sodium salts.", "For example, enanthic acid has a low solubility in water (0.2 g/L), but its sodium salt is very soluble in water.", ":500px===Boiling points===Carboxylic acids tend to have higher boiling points than water, because of their greater surface areas and their tendency to form stabilized dimers through hydrogen bonds.", "For boiling to occur, either the dimer bonds must be broken or the entire dimer arrangement must be vaporized, increasing the enthalpy of vaporization requirements significantly.", ":dimers|alt=|none===Acidity===Carboxylic acids are Brønsted–Lowry acids because they are proton (H+) donors.", "They are the most common type of organic acid.Carboxylic acids are typically weak acids, meaning that they only partially dissociate into cations and anions in neutral aqueous solution.", "For example, at room temperature, in a 1-molar solution of acetic acid, only 0.001% of the acid are dissociated (i.e.", "10−5 moles out of 1 mol).", "Electron-withdrawing substituents, such as -CF3 group, give stronger acids (the p''K''a of acetic acid is 4.76 whereas trifluoroacetic acid, with a trifluoromethyl substituent, has a p''K''a of 0.23).", "Electron-donating substituents give weaker acids (the p''K''a of formic acid is 3.75 whereas acetic acid, with a methyl substituent, has a p''K''a of 4.76) Carboxylic acid p''K''aFormic acid () 3.75Chloroformic acid () 0.27Acetic acid () 4.76Glycine ()2.34Fluoroacetic acid () 2.586Difluoroacetic acid () 1.33Trifluoroacetic acid () 0.23Chloroacetic acid () 2.86Dichloroacetic acid () 1.29Trichloroacetic acid () 0.65Benzoic acid ()4.22-Nitrobenzoic acid (''ortho''-)2.16Oxalic acid () (first dissociation) 1.27Hydrogen oxalate () (second dissociation of oxalic acid)4.14Deprotonation of carboxylic acids gives carboxylate anions; these are resonance stabilized, because the negative charge is delocalized over the two oxygen atoms, increasing the stability of the anion.", "Each of the carbon–oxygen bonds in the carboxylate anion has a partial double-bond character.", "The carbonyl carbon's partial positive charge is also weakened by the -1/2 negative charges on the 2 oxygen atoms.===Odour===Carboxylic acids often have strong sour odours.", "Esters of carboxylic acids tend to have fruity, pleasant odours, and many are used in perfume.=== Characterization ===Carboxylic acids are readily identified as such by infrared spectroscopy.", "They exhibit a sharp band associated with vibration of the C=O carbonyl bond (''ν''C=O) between 1680 and 1725 cm−1.A characteristic ''ν''O–H band appears as a broad peak in the 2500 to 3000 cm−1 region.", "By 1H NMR spectrometry, the hydroxyl hydrogen appears in the 10–13 ppm region, although it is often either broadened or not observed owing to exchange with traces of water." ], [ "Occurrence and applications", "Many carboxylic acids are produced industrially on a large scale.", "They are also frequently found in nature.", "Esters of fatty acids are the main components of lipids and polyamides of aminocarboxylic acids are the main components of proteins.Carboxylic acids are used in the production of polymers, pharmaceuticals, solvents, and food additives.", "Industrially important carboxylic acids include acetic acid (component of vinegar, precursor to solvents and coatings), acrylic and methacrylic acids (precursors to polymers, adhesives), adipic acid (polymers), citric acid (a flavor and preservative in food and beverages), ethylenediaminetetraacetic acid (chelating agent), fatty acids (coatings), maleic acid (polymers), propionic acid (food preservative), terephthalic acid (polymers).", "Important carboxylate salts are soaps." ], [ "Synthesis", "===Industrial routes===In general, industrial routes to carboxylic acids differ from those used on a smaller scale because they require specialized equipment.", "*Carbonylation of alcohols as illustrated by the Cativa process for the production of acetic acid.", "Formic acid is prepared by a different carbonylation pathway, also starting from methanol.", "*Oxidation of aldehydes with air using cobalt and manganese catalysts.", "The required aldehydes are readily obtained from alkenes by hydroformylation.", "*Oxidation of hydrocarbons using air.", "For simple alkanes, this method is inexpensive but not selective enough to be useful.", "Allylic and benzylic compounds undergo more selective oxidations.", "Alkyl groups on a benzene ring are oxidized to the carboxylic acid, regardless of its chain length.", "Benzoic acid from toluene, terephthalic acid from ''para''-xylene, and phthalic acid from ''ortho''-xylene are illustrative large-scale conversions.", "Acrylic acid is generated from propene.", "*Oxidation of ethene using silicotungstic acid catalyst.", "*Base-catalyzed dehydrogenation of alcohols.", "*Carbonylation coupled to the addition of water.", "This method is effective and versatile for alkenes that generate secondary and tertiary carbocations, e.g.", "isobutylene to pivalic acid.", "In the Koch reaction, the addition of water and carbon monoxide to alkenes or alkynes is catalyzed by strong acids.", "Hydrocarboxylations involve the simultaneous addition of water and CO.", "Such reactions are sometimes called \"Reppe chemistry.", "\":* Hydrolysis of triglycerides obtained from plant or animal oils.", "These methods of synthesizing some long-chain carboxylic acids are related to soap making.", "*Fermentation of ethanol.", "This method is used in the production of vinegar.", "*The Kolbe–Schmitt reaction provides a route to salicylic acid, precursor to aspirin.===Laboratory methods===Preparative methods for small scale reactions for research or for production of fine chemicals often employ expensive consumable reagents.", "*Oxidation of primary alcohols or aldehydes with strong oxidants such as potassium dichromate, Jones reagent, potassium permanganate, or sodium chlorite.", "The method is more suitable for laboratory conditions than the industrial use of air, which is \"greener\" because it yields less inorganic side products such as chromium or manganese oxides.", "*Oxidative cleavage of olefins by ozonolysis, potassium permanganate, or potassium dichromate.", "*Hydrolysis of nitriles, esters, or amides, usually with acid- or base-catalysis.", "*Carbonation of a Grignard reagent and organolithium reagents:::* Halogenation followed by hydrolysis of methyl ketones in the haloform reaction* Base-catalyzed cleavage of non-enolizable ketones, especially aryl ketones::===Less-common reactions===Many reactions produce carboxylic acids but are used only in specific cases or are mainly of academic interest.", "* Disproportionation of an aldehyde in the Cannizzaro reaction* Rearrangement of diketones in the benzilic acid rearrangement* Involving the generation of benzoic acids are the von Richter reaction from nitrobenzenes and the Kolbe–Schmitt reaction from phenols." ], [ "Reactions", "Carboxylic acid organic reactionsThe most widely practiced reactions convert carboxylic acids into esters, amides, carboxylate salts, acid chlorides, and alcohols.", "Carboxylic acids react with bases to form carboxylate salts, in which the hydrogen of the hydroxyl (–OH) group is replaced with a metal cation.", "For example, acetic acid found in vinegar reacts with sodium bicarbonate (baking soda) to form sodium acetate, carbon dioxide, and water::Carboxylic acids also react with alcohols to give esters.", "This process is widely used, e.g.", "in the production of polyesters.", "Likewise, carboxylic acids are converted into amides, but this conversion typically does not occur by direct reaction of the carboxylic acid and the amine.", "Instead esters are typical precursors to amides.", "The conversion of amino acids into peptides is a significant biochemical process that requires ATP.The hydroxyl group on carboxylic acids may be replaced with a chlorine atom using thionyl chloride to give acyl chlorides.", "In nature, carboxylic acids are converted to thioesters.=== Reduction ===Like esters, most carboxylic acids can be reduced to alcohols by hydrogenation, or using hydride transferring agents such as lithium aluminium hydride.", "Strong alkyl transferring agents, such as organolithium compounds but not Grignard reagents, will reduce carboxylic acids to ketones along with transfer of the alkyl group.Vilsmaier reagent (''N'',''N''-Dimethyl(chloromethylene)ammonium chloride ClHC\\dN+(CH3)2Cl−) is a highly chemoselective agent for carboxylic acid reduction.", "It selectively activates the carboxylic acid to give the carboxymethyleneammonium salt, which can be reduced by a mild reductant like lithium tris(''t''-butoxy)aluminum hydride to afford an aldehyde in a one pot procedure.", "This procedure is known to tolerate reactive carbonyl functionalities such as ketone as well as moderately reactive ester, olefin, nitrile, and halide moieties.===Specialized reactions===* As with all carbonyl compounds, the protons on the α-carbon are labile due to keto–enol tautomerization.", "Thus, the α-carbon is easily halogenated in the Hell–Volhard–Zelinsky halogenation.", "* The Schmidt reaction converts carboxylic acids to amines.", "* Carboxylic acids are decarboxylated in the Hunsdiecker reaction.", "* The Dakin–West reaction converts an amino acid to the corresponding amino ketone.", "* In the Barbier–Wieland degradation, a carboxylic acid on an aliphatic chain having a simple methylene bridge at the alpha position can have the chain shortened by one carbon.", "The inverse procedure is the Arndt–Eistert synthesis, where an acid is converted into acyl halide, which is then reacted with diazomethane to give one additional methylene in the aliphatic chain.", "* Many acids undergo oxidative decarboxylation.", "Enzymes that catalyze these reactions are known as carboxylases (EC 6.4.1) and decarboxylases (EC 4.1.1).", "* Carboxylic acids are reduced to aldehydes via the ester and DIBAL, via the acid chloride in the Rosenmund reduction and via the thioester in the Fukuyama reduction.", "* In ketonic decarboxylation carboxylic acids are converted to ketones.", "* Organolithium reagents (>2 equiv) react with carboxylic acids to give a dilithium 1,1-diolate, a stable tetrahedral intermediate which decomposes to give a ketone upon acidic workup.", "* The Kolbe electrolysis is an electrolytic, decarboxylative dimerization reaction.", "It gets rid of the carboxyl groups of two acid molecules, and joins the remaining fragments together." ], [ "Carboxyl radical", "The carboxyl radical, •COOH, only exists briefly.", "The acid dissociation constant of •COOH has been measured using electron paramagnetic resonance spectroscopy.", "The carboxyl group tends to dimerise to form oxalic acid." ], [ "See also", "* Acid anhydride* Acid chloride* Amide* Amino acid* Ester* List of carboxylic acids* Dicarboxylic acid* Pseudoacid* Thiocarboxy* Carbon dioxide (CO2)" ], [ "References" ], [ "External links", "* Carboxylic acids pH and titration – freeware for calculations, data analysis, simulation, and distribution diagram generation* PHC." ] ]
wikipedia
[ [ "Chernobyl" ], [ "Introduction", "'''Chernobyl''' ( , ; , ) or '''Chornobyl''' (, ) is a partially abandoned city in the Chernobyl Exclusion Zone, situated in the Vyshhorod Raion of northern Kyiv Oblast, Ukraine.", "Chernobyl is about north of Kyiv, and southwest of the Belarusian city of Gomel.", "Before its evacuation, the city had about 14,000 residents (considerably less than neighboring Pripyat).", "While living anywhere within the Chernobyl Exclusion Zone is technically illegal today, authorities tolerate those who choose to live within some of the less irradiated areas, and around 1,000 people live in Chernobyl today.First mentioned as a ducal hunting lodge in 1193, the city has changed hands multiple times over the course of history.", "Jews moved into the city in the 16th century, and a now-defunct monastery was established in the area in 1626.By the end of the 18th century, Chernobyl was a major centre of Hasidic Judaism under the Twersky Dynasty, which left Chernobyl after the city was subjected to pogroms in the early 20th century.", "The Jewish community was later murdered during the Holocaust.", "Chernobyl was chosen as the site of Ukraine's first nuclear power plant in 1972, located north of the city, which opened in 1977.Chernobyl was evacuated on 5 May 1986, nine days after a catastrophic nuclear disaster at the plant, which was the largest nuclear disaster in history.", "Along with the residents of the nearby city of Pripyat, which was built as a home for the plant's workers, the population was relocated to the newly built city of Slavutych, and most have never returned.Mir station, 1997The city was the administrative centre of Chernobyl Raion (district) from 1923.After the disaster, in 1988, the raion was dissolved and administration was transferred to the neighbouring Ivankiv Raion.", "The raion was abolished on 18 July 2020 as part of the administrative reform of Ukraine, which reduced the number of raions of Kyiv Oblast to seven.", "The area of Ivankiv Raion was merged into Vyshhorod Raion.Although Chernobyl is primarily a ghost town today, a small number of people still live there, in houses marked with signs that read, \"Owner of this house lives here\", and a small number of animals live there as well.", "Workers on watch and administrative personnel of the Chernobyl Exclusion Zone are also stationed in the city.", "The city has two general stores and a hotel.During the 2022 Russian invasion of Ukraine, Chernobyl was temporarily captured and occupied by Russian forces between 24 February and 2 April.", "After its capture, it was reported that radiation levels temporarily rose, due to human activities, including earthworks, which disturbed the dust." ], [ "Etymology", "Chernobyl welcome signThe city's name is the same as one of the Ukrainian names for ''Artemisia vulgaris'', mugwort or common wormwood: (or more commonly , 'common artemisia').", "The name is inherited from or , a compound of + , the parts related to and , 'stalk', so named in distinction to the lighter-stemmed wormwood ''A.", "absinthium''.The name in languages used nearby is:*, *, *, .The name in languages formerly used in the area is:*, *, .In English, the Russian-derived spelling ''Chernobyl'' has been commonly used, but some style guides recommend the spelling ''Chornobyl'', or the use of romanized Ukrainian names for Ukrainian places generally." ], [ "History", "Orthodox Church of St. ElijahA 1525 European Sarmatia map after Ptolemy's ''Geography''.", "Azagarium is marked on the west bank of the Boristhenes river (Dnieper), below the \"Sarmatia Europe\" inscription, east (right) of the lake captioned \"Amodora palus\".", "\"Paludes Meotides\" (Maeotian Swamp) is the Sea of Azov, \"Ponti Euxini pars\" marks the Black Sea, and the Carpathians are drawn in the bottom left (southwest) corner as \"Carpatus mons\".The Polish Geographical Dictionary of the Kingdom of Poland of 1880–1902 states that the time the city was founded is not known.===Identity of Ptolemy's \"Azagarium\"===Some older geographical dictionaries and descriptions of modern Eastern Europe mention \"Czernobol\" (Chernobyl) with reference to Ptolemy's world map (2nd century AD).", "Czernobol is identified as \"oppidium Sarmatiae\" (Lat., \"a city in Sarmatia\"), by the 1605 ''Lexicon geographicum'' of Filippo Ferrari and the 1677 ''Lexicon Universale'' of Johann Jakob Hofmann.", "According to the ''Dictionary of Ancient Geography'' of Alexander Macbean (London, 1773), Azagarium is \"a town of Sarmatia Europaea, on the Borysthenes\" (Dnieper), 36° East longitude and 50°40' latitude.", "The city is \"now supposed to be ''Czernobol'', a town of Poland, in Red Russia Red Ruthenia, in the Palatinate of Kiow see Kiev Voivodeship, not far from the Borysthenes.", "\"Whether Azagarium is indeed Czernobol is debatable.", "The question of Azagarium's correct location was raised in 1842 by Habsburg-Slovak historian, Pavel Jozef Šafárik, who published a book titled \"Slavic Ancient History\" (\"Sławiańskie starożytności\"), where he claimed Azagarium to be the hill of Zaguryna, which he found on an old Russian map \"Bolzoj czertez\" (Big drawing) near the city of Pereiaslav, now in central Ukraine.In 2019, Ukrainian architect Boris Yerofalov-Pylypchak published a book, ''Roman Kyiv or Castrum Azagarium at Kyiv-Podil''.===12th to 18th century===The archaeological excavations that were conducted in 2005–2008 found a cultural layer from the 10–12th centuries AD, which predates the first documentary mention of Chernobyl.Around the 12th century Chernobyl was part of the land of Kievan Rus′.", "The first known mention of the settlement as Chernobyl is from an 1193 charter, which describes it as a hunting lodge of Knyaz Rurik Rostislavich.", "In 1362 it was a crown village of the Grand Duchy of Lithuania.", "Around that time the town had own castle which was ruined at least on two occasions in 1473 and 1482.The Chernobyl castle was rebuilt in the first quarter of the 16th century being located nearby the settlement in a hard to reach area.", "With revival of the castle, Chernobyl became a county seat.", "In 1552 it accounted for 196 buildings with 1,372 residents, out of which over 1,160 were considered city dwellers.", "In the city were developing various crafts professions such as blacksmith, cooper among others.", "Near Chernobyl has been excavated bog iron, out of which was produced iron.", "The village was granted to Filon Kmita, a captain of the royal cavalry, as a fiefdom in 1566.Following the Union of Lublin, the province where Chernobyl is located was transferred to the Crown of the Kingdom of Poland in 1569.Under the Polish Crown, Chernobyl became a seat of eldership (starostwo).", "During that period Chernobyl was inhabited by Ukrainian peasants, some Polish people and a relatively large number of Jews.", "Jews were brought to Chernobyl by Filon Kmita, during the Polish campaign of colonization.", "The first mentioning of Jewish community in Chernobyl is in the 17th century.", "In 1600 the first Roman Catholic church was built in the town.", "Local population was persecuted for holding Eastern Orthodox rite services.", "The traditionally Eastern Orthodox Ukrainian peasantry around the town were forcibly converted, by Poland, to the Ruthenian Uniate Church.", "In 1626, during the Counter-reformation, a Dominican church and monastery were founded by Lukasz Sapieha.", "A group of Old Catholics opposed the decrees of the Council of Trent.", "The Chernobyl residents actively supported the Khmelnytsky Uprising (1648–1657).With the signing of the Truce of Andrusovo in 1667, Chernobyl was secured after the Sapieha family.", "Sometime in the 18th century, the place was passed on to the Chodkiewicz family.", "In the mid-18th century the area around Chernobyl was engulfed in a number of peasant riots, which caused Prince Riepnin to write from Warsaw to Major General Krechetnikov, requesting hussars to be sent from Kharkiv to deal with the uprising near Chernobyl in 1768.The 8th Lithuanian Infantry Regiment was stationed in the town in 1791.By the end of the 18th century, the town accounted for 2,865 residents and had 642 buildings.===18th century to Soviet times: demography and events===Following the Second Partition of Poland, in 1793 Chernobyl was annexed by the Russian Empire and became part of Radomyshl county (''uezd'') as a supernumerary town (\"zashtatny gorod\").", "Many of the Uniate Church converts returned to Eastern Orthodoxy.In 1832, following the failed Polish November Uprising, the Dominican monastery was sequestrated.", "The church of the Old Catholics was disbanded in 1852.Until the end of the 19th century, Chernobyl was a privately owned city that belonged to the Chodkiewicz family.", "In 1896 they sold the city to the state, but until 1910 they owned a castle and a house in the city.In the second half of the 18th century, Chernobyl became a major centre of Hasidic Judaism.", "The Chernobyl Hasidic dynasty had been founded by Rabbi Menachem Nachum Twersky.", "The Jewish population suffered greatly from pogroms in October 1905 and in March–April 1919; many Jews were killed or robbed at the instigation of the Russian nationalist Black Hundreds.", "When the Twersky Dynasty left Chernobyl in 1920, it ceased to exist as a center of Hasidism.Chernobyl had a population of 10,800 in 1898, including 7,200 Jews.", "In the beginning of March 1918 Chernobyl was occupied in World War I by German forces (see Treaty of Brest-Litovsk).===Soviet times (1920–1991)===Ukrainians and Bolsheviks fought over the city in the ensuing Civil War.", "In the Polish–Soviet War of 1919–20, Chernobyl was taken first by the Polish Army and then by the cavalry of the Red Army.", "From 1921 onwards, it was officially incorporated into the Ukrainian SSR.Between 1929 and 1933, Chernobyl suffered from killings during Stalin's collectivization campaign.", "It was also affected by the famine that resulted from Stalin's policies.", "The Polish and German community of Chernobyl was deported to Kazakhstan in 1936, during the Frontier Clearances.During World War II, Chernobyl was occupied by the German Army from 25 August 1941 to 17 November 1943.When the Germans arrived, only 400 Jews remained in Chernobyl; they were murdered during the Holocaust.In 1972, the Duga-1 radio receiver, part of the larger Duga over-the-horizon radar array, began construction west-northwest of Chernobyl.", "It was the origin of the Russian Woodpecker and was designed as part of an anti-ballistic missile early warning radar network.On 15 August 1972, the Chernobyl Nuclear Power Plant (officially the Vladimir Ilyich Lenin Nuclear Power Plant) began construction about northwest of Chernobyl.", "The plant was built alongside Pripyat, an \"atomograd\" city founded on 4 February 1970 that was intended to serve the nuclear power plant.", "The decision to build the power plant was adopted by the Central Committee of the Communist Party of the Soviet Union and the Council of Ministers of the Soviet Union on recommendations of the State Planning Committee that the Ukrainian SSR be its location.", "It was the first nuclear power plant to be built in Ukraine.===Independent Ukraine (1991–present)===With the dissolution of the Soviet Union in 1991, Chernobyl remained part of Ukraine within the Chernobyl Exclusion Zone which Ukraine inherited from the Soviet Union.=== Russian occupation (February–April 2022) ===During the 2022 Russian invasion of Ukraine, Russian forces captured the city on 24 February.", "After its capture, Ukrainian officials reported that the radiation levels started to rise due to recent military activity causing radioactive dust to ascend into the air.", "Hundreds of Russian soldiers were suffering from radiation poisoning after digging trenches in a contaminated area, and one died.", "On 31 March it was reported that Russian forces had left the exclusion zone.", "Ukrainian authorities reasserted control over the area on 2 April." ], [ "Geography", "Chernobyl is located about north of Kyiv, and southwest of the Belarusian city of Gomel.===Climate===Chernobyl has a humid continental climate (Dfb) with very warm, wet summers with cool nights and long, cold, and snowy winters." ], [ "Chernobyl nuclear reactor disaster", "Wormwood Star'' Memorial Complex''alt=On 26 April 1986, one of the reactors at the Chernobyl Nuclear Power Plant exploded after unsanctioned experiments on the reactor by plant operators were done improperly.", "The resulting loss of control was due to design flaws of the RBMK reactor, which made it unstable when operated at low power, and prone to thermal runaway where increases in temperature increase reactor power output.Chernobyl city was evacuated nine days after the disaster.", "The level of contamination with caesium-137 was around 555 kBq/m2 (surface ground deposition in 1986).Later analyses concluded that, even with very conservative estimates, relocation of the city (or of any area below 1500 kBq/m2) could not be justified on the grounds of radiological health.This however does not account for the uncertainty in the first few days of the accident about further depositions and weather patterns.Moreover, an earlier short-term evacuation could have averted more significant doses from short-lived isotope radiation (specifically iodine-131, which has a half-life of about eight days).Estimates of health effects are a subject of some controversy, see Effects of the Chernobyl disaster.In 1998, average caesium-137 doses from the accident (estimated at 1–2 mSv per year) did not exceed those from other sources of exposure.", "Current effective caesium-137 dose rates as of 2019 are 200–250 nSv/h, or roughly 1.7–2.2 mSv per year,which is comparable to the worldwide average background radiation from natural sources.The base of operations for the administration and monitoring of the Chernobyl Exclusion Zone was moved from Pripyat to Chernobyl.", "Chernobyl currently contains offices for the State Agency of Ukraine on the Exclusion Zone Management and accommodations for visitors.", "Apartment blocks have been repurposed as accommodations for employees of the State Agency.", "The length of time that workers may spend within the Chernobyl Exclusion Zone is restricted by regulations that have been implemented to limit radiation exposure.", "Today, visits are allowed to Chernobyl but limited by strict rules.In 2003, the United Nations Development Programme launched a project, called the Chernobyl Recovery and Development Programme (CRDP), for the recovery of the affected areas.", "The main goal of the CRDP's activities is supporting the efforts of the Government of Ukraine to mitigate the long-term social, economic, and ecological consequences of the Chernobyl disaster.The city has become overgrown and many types of animals live there.", "According to census information collected over an extended period of time, it is estimated that more mammals live there now than before the disaster.Notably, Mikhail Gorbachev, the final leader of the Soviet Union, stated in respect to the Chernobyl disaster that, \"More than anything else, (Chernobyl) opened the possibility of much greater freedom of expression, to the point that the (Soviet) system as we knew it could no longer continue.\"" ], [ "Notable people", "*Aaron Twersky of Chernobyl (1784–1871), rabbi*Aleksander Franciszek Chodkiewicz (1776–1838), Polish politician and lithographer*Alexander Krasnoshchyokov (1880–1937), politician*Andriy Smalko (1981–), football player*Arnold Lakhovsky (1880–1937), artist*Jan Mikołaj Chodkiewicz (1738–1781), Polish nobleman, father of Rozalia Lubomirska*Ekaterina Scherbachenko (1977–), opera singer*Grigory Irmovich Novak (1919–1980), Jewish Soviet weightlifter*Joshua ben Aaron Zeitlin (1823–1888), scholar and philanthropist*Markiyan Kamysh (1988–), novelist and son of a liquidator*Rozalia Lubomirska (1768–1794), Polish noblewoman guillotined during the French Revolution*Volodymyr Pravyk (1962–1986), firefighter and liquidator" ], [ "See also", "*List of Chernobyl-related articles" ], [ "References" ], [ "External links", "* State Agency of Ukraine on Exclusion Zone Management – official information on public works, zone status, visits, etc.", "* Official radiation measurements – State Agency of Ukraine on Exclusion Zone Management.", "Online map.", "* Chernobyl – History of Jewish Communities in Ukraine ''JewUa.org''* The Chernobyl Gallery" ] ]
wikipedia
[ [ "Cyan" ], [ "Introduction", "'''Cyan''' () is the color between blue and green on the visible spectrum of light.", "It is evoked by light with a predominant wavelength between 490 and 520 nm, between the wavelengths of green and blue.In the subtractive color system, or CMYK color model, which can be overlaid to produce all colors in paint and color printing, cyan is one of the primary colors, along with magenta and yellow.", "In the additive color system, or RGB color model, used to create all the colors on a computer or television display, cyan is made by mixing equal amounts of green and blue light.", "Cyan is the complement of red; it can be made by the removal of red from white.", "Mixing red light and cyan light at the right intensity will make white light." ], [ "Shades and variations of cyan", "Different shades of the color cyan can vary in terms of hue, chroma (also known as saturation, intensity, or colorfulness), or lightness (or value, tone, or brightness), or any combination of these characteristics.", "Differences in value can also be referred to as tints and shades, with a tint being a cyan mixed with white, and a shade being mixed with black.Color nomenclature is subjective.", "Many shades of cyan with a bluish hue are called blue.", "Similarly, those with a greenish hue are referred to as green.", "A cyan with a dark shade is commonly known as teal.", "A '''teal blue''' shade leans toward the blue end of the spectrum.", "Variations of teal with a greener tint are commonly referred to as '''teal green'''.", "Turquoise, reminiscent of the stone with the same name, is a shade in the green spectrum of cyan hues.", "Celeste is a lightly tinted cyan that represents the color a clear sky.", "Other colors in the cyan color range are electric blue, aquamarine, and others described as blue-green." ], [ "History of cyan", "The color cyan holds a rich and significant history, with cultural importance spanning thousands of years.", "In ancient civilizations, turquoise was highly revered as a precious gem for its exceptional beauty.", "Turquoise comes in a variety of shades from green to blue, but cyan hues are particularly prevalent.An extraordinary example of this reverence is a 3,700-year-old dragon-shaped treasure, crafted from over 2,000 pieces of turquoise.", "It is considered by numerous Chinese scholars as the oldest Chinese dragon totem.Additionally, turquoise jewelry held great significance among the Aztecs.", "The vibrant frescoes of ancient Mesoamerican cultures often showcased this valuable gemstone for both symbolic and decorative purposes.", "The Aztecs held turquoise in high esteem, associating it with the heavens and sacredness.", "As a result, they regarded the cyan shade (#30D5C8) of turquoise with utmost reverence." ], [ "Etymology and terminology", "Its name is derived from the Ancient Greek word ''kyanos'' (κύανος), meaning \"dark blue enamel, Lapis lazuli\".", "It was formerly known as \"cyan blue\" or cyan-blue, and its first recorded use as a color name in English was in 1879.Further origins of the color name can be traced back to a dye produced from the cornflower (''Centaurea cyanus'').In most languages, 'cyan' is not a basic color term and it phenomenologically appears as a greenish vibrant hue of blue to most English speakers.", "Other English terms for this \"borderline\" hue region include ''blue green'', ''aqua'', ''turquoise'', ''teal'', and ''grue''." ], [ "Cyan on the web and printing", "===The web colors cyan and aqua===The web color cyan shown at right is a secondary color in the RGB color model, which uses combinations of red, green and blue light to create all the colors on computer and television displays.", "In X11 colors, this color is called both cyan and aqua.", "In the HTML color list, this same color is called aqua.The web colors are more vivid than the cyan used in the CMYK color system, and the web colors cannot be accurately reproduced on a printed page.", "To reproduce the web color cyan in inks, it is necessary to add some white ink to the printer's cyan below, so when it is reproduced in printing, it is not a primary subtractive color.", "It is called ''aqua'' (a name in use since 1598) because it is a color commonly associated with water, such as the appearance of the water at a tropical beach.===Process cyan===Cyan is also one of the common inks used in four-color printing, along with magenta, yellow, and black; this set of colors is referred to as CMYK.", "In printing, the cyan ink is sometimes known as printer's cyan, process cyan, or process blue.While both the additive secondary and the subtractive primary are called ''cyan'', they can be substantially different from one another.", "Cyan printing ink is typically more saturated than the RGB secondary cyan, depending on what RGB color space and ink are considered.", "That is, process cyan is usually outside the RGB gamut, and there is no fixed conversion from CMYK primaries to RGB.", "Different formulations are used for printer's ink, so there can be variations in the printed color that is pure cyan ink.", "This is because real-world subtractive (unlike additive) color mixing does not consistently produce the same result when mixing apparently identical colors, since the specific frequencies filtered out to produce that color affect how it interacts with other colors.", "Phthalocyanine blue is one such commonly used pigment.", "A typical formulation of ''process cyan'' is shown in the color box on the right." ], [ "In science and nature", "===Color of water===* Pure water is nearly colorless.", "However, it does absorb slightly more red light than blue, giving significant volumes of water a bluish tint; increased scattering of blue light due to fine particles in the water shifts the blue color toward green, for a typically cyan net color.===Cyan and cyanide===* Cyanide derives its name from Prussian blue, a blue pigment containing the cyanide ion.===Bacteria===* Cyanobacteria (sometimes called blue-green algae) are an important link in the food chain.===Astronomy===* The planet Uranus is colored cyan because of the abundance of methane in its atmosphere.", "Methane absorbs red light and reflects the blue-green light which allows observers to see it as cyan.===Energy===* Natural gas (methane), used by many for home cooking on gas stoves, has a cyan colored flame when burned with a mixture of air.===Photography and film===* Cyanotype, or blueprint, a monochrome photographic printing process that predates the use of the word ''cyan'' as a color, yields a deep ''cyan-blue'' colored print based on the Prussian blue pigment.", "* Cinecolor, a bi-pack color process, the photographer would load a standard camera with two films, one orthochromatic, dyed red, and a panchromatic strip behind it.", "Color light would expose the cyan record on the ortho stock, which also acted as a filter, exposing only red light to the panchromatic film stock.===Medicine===* Cyanosis is an abnormal blueness of the skin, usually a sign of poor oxygen intake; patients are typically described as being \"cyanotic\".", "* Cyanopsia is a color vision defect where vision is tinted blue.", "This can be a drug-induced side effect or experienced after cataract removal." ], [ "Gallery", "File:Green and blue make cyan.png|In the RGB color model, used to make colors on computer and TV displays, cyan is created by the combination of green and blue light.File:RGB color wheel.svg|In the RGB color wheel of subtractive colors, cyan is midway between blue and green.File:SubtractiveColor.svg|In the CMYK color model, used in color printing, cyan, magenta and yellow combined make grey.", "In practice, since the inks are not perfect, some black ink is added.File:Refill Ink Kit Color crop.jpg|Color printers today use, magenta, cyan and yellow ink to produce a wide range of colors.File:Komplementärfarben cyan auf rot.png|Cyan and red are contrasting colors.", "They have strong contrast and harmony, and if combined, they make grey.File:Wham-a different corner.jpg|Cyan is the color of shallow water over a sandy beach.", "The water absorbs the color red from the sunlight, leaving a greenish-blue color.File:Samarkand05.jpg|The dome of the Tilla Kari Mosque in Samarkand, Uzbekistan (1660) is cyan.", "The color is widely used in architecture in Turkey and Central Asia.File:Uranus as seen by NASA's Voyager 2.tif|The planet Uranus, seen from the ''Voyager 2'' spacecraft.", "The cyan color comes from clouds of methane gas in the planet's atmosphere.File:Wirbelsäulenoperation OKM.jpg|alt=A surgical team in Germany.", "It has been suggested that surgeons and nurses adopted a cyan-colored gown and operating rooms because it is complementary to the color of red blood and thus reduced glare, though the evidence for this claim is limited.|A surgical team in Germany.", "It has been suggested that surgeons and nurses adopted a cyan-colored gown and operating rooms because it contrasts the color of red blood, thus reducing glare, though the evidence for this claim is limited.File:Old photo colors degredated into cyan.jpg|The pigments in color photographs may degrade at different rates, potentially resulting in a cyan tint." ], [ "See also", "* Blue–green distinction in language* Shades of cyan * Lists of colors" ], [ "References" ] ]
wikipedia
[ [ "Conventional insulin therapy" ], [ "Introduction", "'''Conventional insulin therapy''' is a therapeutic regimen for treatment of diabetes mellitus which contrasts with the newer intensive insulin therapy.This older method (prior to the development home blood glucose monitoring) is still in use in a proportion of cases." ], [ "Characteristics", "Conventional insulin therapy is characterized by:* Insulin injections of a mixture of regular (or rapid) and intermediate acting insulin are performed two times a day, or to improve overnight glucose, mixed in the morning to cover breakfast and lunch, but with regular (or rapid) acting insulin alone for dinner and intermediate acting insulin at bedtime (instead of being mixed in at dinner).", "* Meals are scheduled to match the anticipated peaks in the insulin profiles.", "* The target range for blood glucose levels is higher than is desired in the intensive regimen.", "* Frequent measurements of blood glucose levels were not used." ], [ "Effects", "The down side of this method is that it is difficult to achieve as good results of glycemic control as with intensive insulin therapy.", "The advantage is that, for diabetics with a regular lifestyle, the regime is less intrusive than the intensive therapy." ], [ "References" ] ]
wikipedia
[ [ "Cream" ], [ "Introduction", "A bottle of unhomogenised milk, with the cream clearly visible, resting on top of the milk'''Cream''' is a dairy product composed of the higher-fat layer skimmed from the top of milk before homogenization.", "In un-homogenized milk, the fat, which is less dense, eventually rises to the top.", "In the industrial production of cream, this process is accelerated by using centrifuges called \"separators\".", "In many countries, it is sold in several grades depending on the total butterfat content.", "It can be dried to a powder for shipment to distant markets, and contains high levels of saturated fat.Cream skimmed from milk may be called \"sweet cream\" to distinguish it from cream skimmed from whey, a by-product of cheese-making.", "Whey cream has a lower fat content and tastes more salty, tangy, and \"cheesy\".", "In many countries partially fermented cream is also sold: sour cream, crème fraîche, and so on.", "Both forms have many culinary uses in both sweet and savoury dishes.Cream produced by cattle (particularly Jersey cattle) grazing on natural pasture often contains some carotenoid pigments derived from the plants they eat; traces of these intensely colored pigments give milk a slightly yellow tone, hence the name of the yellowish-white color: cream.", "Carotenoids are also the origin of butter's yellow color.", "Cream from goat's milk, water buffalo milk, or from cows fed indoors on grain or grain-based pellets, is white." ], [ "Cuisine", "Christmas cake covered with whipping creamCream is used as an ingredient in many foods, including ice cream, many sauces, soups, stews, puddings, and some custard bases, and is also used for cakes.", "Whipped cream is served as a topping on ice cream sundaes, milkshakes, lassi, eggnog, sweet pies, strawberries, blueberries, or peaches.", "Cream is also used in Indian curries such as masala dishes.Cream (usually light/single cream or half and half) may be added to coffee.Both single and double cream (see Types for definitions) can be used in cooking.", "Double cream or full-fat crème fraîche is often used when the cream is added to a hot sauce, to prevent it separating or \"splitting\".", "Double cream can be thinned with milk to make an approximation of single cream.The French word denotes not only dairy cream but also other thick liquids such as sweet and savory custards, which are normally made with milk, not cream." ], [ "Types", "Stewed nectarines and heavy creamDifferent grades of cream are distinguished by their fat content, whether they have been heat-treated, whipped, and so on.", "In many jurisdictions, there are regulations for each type.===Australia and New Zealand===The Australia New Zealand Food Standards Code – Standard 2.5.2 – Defines cream as a milk product comparatively rich in fat, in the form of an emulsion of fat-in-skim milk, which can be obtained by separation from milk.", "Cream sold without further specification must contain no less than 350 g/kg (35%) milk fat.Manufacturers labels may distinguish between different fat contents, a general guideline is as follows: Name Fat content Main uses Extra light (or 'lite') 12–12.5% Light (or 'lite') 18–20% Thickened cream 35–36.5% Cream with added gelatine and/or other thickeners to give the cream a thicker texture, also possibly with stabilisers to aid the consistency of whipped cream.", "Such cream would not typically be used for cooking.", "Cream >= 35% Recipes calling for cream are usually referring to pure cream with about 35% fat.", "This is used for cooking as well as for pouring and whipping.", "It is comparable to ''whipping cream'' in some other countries.", "Double cream 48–60%=== Canada ===Canadian cream definitions are similar to those used in the United States, except for \"light cream\", which is very low-fat cream, usually with 5 or 6 percent butterfat.", "Specific product characteristics are generally uniform throughout Canada, but names vary by both geographic and linguistic area and by manufacturer: \"coffee cream\" may be 10 or 18 percent cream and \"half-and-half\" () may be 3, 5, 6 or 10 percent, all depending on location and brand.Regulations allow cream to contain acidity regulators and stabilizers.", "For whipping cream, allowed additives include skim milk powder (≤ 0.25%), glucose solids (≤ 0.1%), calcium sulphate (≤ 0.005%), and xanthan gum (≤ 0.02%).", "The content of milk fat in canned cream must be displayed as a percentage followed by \"milk fat\", \"B.F\", or \"M.F\".", "Name Minimum milk fat Additional definition Main uses Manufacturing cream 40%Crème fraîche is also 40–45% but is an acidified cultured product rather than sweet cream.", "Commercial production.", "Whipping cream 33–36% Also as cooking or \"thick\" cream 35% with added stabilizers.", "Heavy cream must be at least 36%.", "In Francophone areas: crème à fouetter 35%; and for cooking, crème à cuisson 35%, crème à l'ancienne 35% or crème épaisse 35%.", "Whips into a creamy and smooth topping that is used for pastries, fresh fruits, desserts, hot cocoa, etc.", "Cooking version is formulated to resist breaking when heated (as in sauces).", "Table cream 15–18% Coffee cream.", "Also as cooking or \"thick\" cream 15% with added stabilizers.", "In Francophone areas: crème de table 15% or crème à café 18%; and for cooking, crème champêtre 15%, crème campagnarde (country cream) 15% or crème épaisse 15%.", "Added as rich whitener to coffee.", "Ideal for soups, sauces and veloutés.", "Garnishing fruit and desserts.", "Cooking version is formulated to resist breaking when heated.", "Half and half 10% Cereal cream.", "Product with the most butterfat in the light cream category.", "In Francophone areas: crème à café 10% and sometimes crème légère 10%.", "Approximately equal to a 50/50 blend of table cream (at 16–18%) and whole milk (at 3.25%), hence the common name in English.", "Poured over hot cereal as a garnish.", "Ideal in sauces for vegetables, fish, meat, poultry, and pasta.", "Also in cream soups.", "Light cream 3–10% Light cream 6%.", "In Francophone areas: mélange de lait et de crème pour café 5%, Crémette™ 5% or crème légère 3% to 10%.", "A mixture of milk and cream.", "5% product is similar to the richest Guernsey or Jersey milk.", "A lower fat alternative to table cream in coffee.=== France ===In France, the use of the term \"cream\" for food products is defined by the decree 80-313 of April 23, 1980.It specifies the minimum rate of milk fat (12%) as well as the rules for pasteurisation or UHT sterilisation.", "The mention \"crème fraîche\" (fresh cream) can only be used for pasteurised creams conditioned on production site within 24h after pasteurisation.", "Even if food additives complying with French and European laws are allowed, usually, none will be found in plain \"crèmes\" and \"crèmes fraîches\" apart from lactic ferments (some low cost creams (or close to creams) can contain thickening agents, but rarely).", "Fat content is commonly shown as \"XX% M.G.\"", "(\"matière grasse\").+NameMilk fatDefinitionMain uses'''Without lactic ferments added (liquid texture)'''Crème fraîche crue30 to 40%Directly from the farm production.", "Local food circuits.", "No sterilisation and no pasteurisation.Crème fleurette30%No sterilisation but pasteurised.", "Liquid and soft the first days, it gets heavier and develops a more pronounced taste with time.Commonly used by cooks in restaurants.Crème entière liquide22 to 40%UHT sterilised (in France, a cream can not legally be called \"fraîche\" if it has been UHT sterilised).Crème fraîche liquide:30 to 40%(usually 30%)Pasteurised (can be called \"fraîche\").Mostly used for fruit desserts and to make crème chantilly or ganaches.", "Can also be used to make white sauces or added in soups or pastas.Crème fraîche légère liquide12 to 21%(usually 15%)Pasteurised (can be called \"fraîche\").", "Less fat.Can be used for the same recipes as the non diet one but sometimes considered as less tasty and/or less convenient to cook with.", "'''With lactic ferments added (heavy texture)'''Crème crue maturée30 to 40%Directly from the farm production.", "Local food circuits.", "No sterilisation and no pasteurisation.Crème entière épaisse22 to 40%UHT sterilised (in France, a cream can not legally be called \"fraîche\" if it has been UHT sterilised).Crème fraîche épaisse30 to 40%(usually 30%)Pasteurised (can be called \"fraîche\").Suits best for cooking especially reductions and liaisons (used as a binding agent).", "Also used to cook quiches (such as quiche Lorraine).Crème fraîche légère épaisse12 to 21%(usually 15%)Pasteurised (can be called \"fraîche\").", "Less fat.Can be used for the same recipes as the non diet one but sometimes considered as less tasty and/or less convenient to cook with.Crème aigre16 to 21%More acidic taste.Same product as the American sour cream or the Canadian crème sure, but rarely used in France.=== Russia ===Russia, as well as other EAC countries, legally separates cream into two classes: normal (10–34% butterfat) and heavy (35–58%), but the industry has pretty much standardized around the following types: English Russian Transliteration Milk fat (wt%) Low-fat or drinking cream Нежирные (питьевые) сливки Nezhirnÿe (pityevÿe) slivki 10% (Normal) Cream Сливки Slivki 15% or 20% Whipping cream Сливки для взбивания Slivki dlya vzbivaniya 33% or 35% Double cream Двойные (жирные) сливки Dvoinÿe (Zhirnÿe) slivki 48%===Sweden===In Sweden, cream is usually sold as:*Matlagningsgrädde (\"''cooking cream''\"), 10–15%*Kaffegrädde (\"''Coffee cream''\"), 10–12%, earlier mostly 12%*Vispgrädde (''whipping cream''), 36–40%, the 36% variant often has additives.Mellangrädde (27%) is, nowadays, a less common variant.", "Gräddfil (usually 12%) and Creme Fraiche (usually around 35%) are two common sour cream products.=== Switzerland ===In Switzerland, the types of cream are legally defined as follows: English German French Italian Typicalmilk fatwt% Minimummilk fatwt% Double cream Doppelrahm double-crème doppia panna 45% 45% Full cream Whipping creamCream VollrahmSchlagrahmRahmSahne crème entièrecrème à fouettercrème panna interapanna da montarepanna 35% 35% Half cream Halbrahm demi-crème mezza panna 25% 15% Coffee cream Kaffeerahm crème à café panna da caffè 15% 15%Sour cream and crème fraîche (German: Sauerrahm, Crème fraîche; French: crème acidulée, crème fraîche; Italian: panna acidula, crème fraîche) are defined as cream soured by bacterial cultures.Thick cream (German: ; French: ; Italian: ) is defined as cream thickened using thickening agents.===United Kingdom===In the United Kingdom, these types of cream are produced.", "Fat content must meet the Food Labelling Regulations 1996.Name Minimum milk fat Additional definition Main uses Clotted cream 55% is clotted (by heat treatment) Clotted cream is the thickest cream available and a traditional part of a cream tea and is spread onto scones like butter.", "Extra-thick double cream 48% is heat-treated, then quickly cooled Extra-thick double cream is the second thickest cream available.", "It is spooned onto pies, puddings, and desserts due to its heavy consistency.", "Double cream 48% Double cream whips easily and produces heavy whipped cream for puddings and desserts.", "Whipping cream 35% Whipping cream whips well and produces lighter whipped cream than double cream.", "Whipped cream 35% has been whipped Whipped cream is used for decorations on cakes, topping for ice cream, and fruit.", "Sterilized cream 23% is sterilized Cream or single cream 18% is not sterilized Single cream is poured over puddings, used in sauces, and added to coffee.", "Extra-thick single cream 18% not sterilized; homogenised for consistency like double cream Sterilized half cream 12% is sterilized Half cream 12% Uncommon.", "Used in some cocktails.===United States===In the United States, cream is usually sold as: Name Fat content Main uses Half and half 10.5% to 18% Half and half is equal parts milk and light cream, and is added to coffee.", "Light cream 18% to 30% Light cream is added to coffee and hot cereal, and is also used as an ingredient in sauces and other recipes.", "Whipping cream 30% to 36% Whipping cream is used in sauces and soups, and as a garnish.", "Whipping cream will only produce whipped cream with soft peaks.", "Heavy (whipping) cream At least 36% Heavy whipping cream produces whipped cream with stable peaks.", "Manufacturer's cream At least 40% Used in commercial and professional production applications.", "Not generally available at retail until recently.Not all grades are defined by all jurisdictions, and the exact fat content ranges vary.", "The above figures, except for \"manufacturer's cream\", are based on the Code of Federal Regulations, Title 21, Part 131." ], [ "Processing and additives", "Cream may have thickening agents and stabilizers added.", "Thickeners include sodium alginate, carrageenan, gelatine, sodium bicarbonate, tetrasodium pyrophosphate, and alginic acid.Other processing may be carried out.", "For example, cream has a tendency to produce oily globules (called \"feathering\") when added to coffee.", "The stability of the cream may be increased by increasing the non-fat solids content, which can be done by partial demineralisation and addition of sodium caseinate, although this is expensive." ], [ "Other cream products", "Chart of 50 types of milk products and relationships, including cream (click on image to enlarge) by churning cream to separate the butterfat and buttermilk.", "This can be done by hand or by machine.", "'''Whipped cream''' is made by whisking or mixing air into cream with more than 30% fat, to turn the liquid cream into a soft solid.", "Nitrous oxide, from whipped-cream chargers may also be used to make whipped cream.", "'''Sour cream''', produced in many countries, is cream (12 to 16% or more milk fat) that has been subjected to a bacterial culture that produces lactic acid (0.5%+), which sours and thickens it.", "'''Crème fraîche''' (28% milk fat) is slightly soured with bacterial culture, but not as sour or as thick as sour cream.", "Mexican '''crema''' (or '''cream espesa''') is similar to crème fraîche.", "'''Smetana''' is a heavy cream-derived (15–40% milk fat) Central and Eastern European sweet or sour cream.", "'''Rjome''' or '''rømme''' is Norwegian sour cream containing 35% milk fat, similar to Icelandic '''sýrður rjómi'''.", "'''Clotted cream''' in the United Kingdom is made through a process that starts by slowly heating whole milk to produce a very high-fat (55%) product, similar to Indian '''malai'''.", "'''Reduced cream''' is a cream product in New Zealand, often used to make Kiwi dip." ], [ "Other items called \"cream\"", "Some non-edible substances are called creams due to their consistency: shoe cream is runny, unlike regular waxy shoe polish; hand/body \"creme\" or \"skin cream\" is meant for moisturizing the skin.Regulations in many jurisdictions restrict the use of the word ''cream'' for foods.", "Words such as ''creme'', ''kreme'', ''creame'', or ''whipped topping'' (e.g., Cool Whip) are often used for products which cannot legally be called cream, though in some jurisdictions even these spellings may be disallowed, for example under the doctrine of ''idem sonans''.", "Oreo and Hydrox cookies are a type of sandwich cookie in which two biscuits have a soft, sweet filling between them that is called \"crème filling.\"", "In some cases, foods can be described as cream although they do not contain predominantly milk fats; for example, in Britain, \"ice cream\" can contain non-milk fat (declared on the label) in addition to or instead of cream, and salad cream is the customary name for a non-dairy condiment that has been produced since the 1920s.In other languages, cognates of \"cream\" are also sometimes used for non-food products, such as fogkrém (Hungarian for toothpaste), or Sonnencreme (German for sunscreen).Some products are described as \"cream alternatives\".", "For example, ''Elmlea Double'', etc.", "are blends of buttermilk or lentils and vegetable oil with other additives sold by Upfield in the United Kingdom packaged and shelved in the same way as cream, labelled as having \"a creamy taste\"." ], [ "See also", "*Buttercream*Condensed milk* Crème, a French culinary term for cream-like preparations**Crème liqueur*Ice cream*Kaymak, which is similar to clotted cream* List of cream soups*Plant cream" ], [ "References" ], [ "External links", "* Nutrition chart for heavy cream* Virtual Museum Exhibit on Milk, Cream & Butter" ] ]
wikipedia
[ [ "Chemical vapor deposition" ], [ "Introduction", "DC plasma (violet) enhances the growth of carbon nanotubes in a laboratory-scale PECVD (plasma-enhanced chemical vapor deposition) apparatus'''Chemical vapor deposition''' ('''CVD''') is a vacuum deposition method used to produce high-quality, and high-performance, solid materials.", "The process is often used in the semiconductor industry to produce thin films.In typical CVD, the wafer (substrate) is exposed to one or more volatile precursors, which react and/or decompose on the substrate surface to produce the desired deposit.", "Frequently, volatile by-products are also produced, which are removed by gas flow through the reaction chamber.Microfabrication processes widely use CVD to deposit materials in various forms, including: monocrystalline, polycrystalline, amorphous, and epitaxial.", "These materials include: silicon (dioxide, carbide, nitride, oxynitride), carbon (fiber, nanofibers, nanotubes, diamond and graphene), fluorocarbons, filaments, tungsten, titanium nitride and various high-κ dielectrics.The term ''chemical vapour deposition'' was coined 1960 by ''John M. Blocher, Jr.'' who intended to differentiate ''chemical'' from ''physical vapour deposition'' (PVD)." ], [ "Types", "Hot-wall thermal CVD (batch operation type)Plasma assisted CVDCVD is practiced in a variety of formats.", "These processes generally differ in the means by which chemical reactions are initiated.", "* Classified by operating conditions:** Atmospheric pressure CVD (APCVD) – CVD at atmospheric pressure.", "** Low-pressure CVD (LPCVD) – CVD at sub-atmospheric pressures.", "Reduced pressures tend to reduce unwanted gas-phase reactions and improve film uniformity across the wafer.", "** Ultrahigh vacuum CVD (UHVCVD) – CVD at very low pressure, typically below 10−6 Pa (≈ 10−8 torr).", "Note that in other fields, a lower division between high and ultra-high vacuum is common, often 10−7 Pa.** Sub-atmospheric CVD (SACVD) – CVD at sub-atmospheric pressures.", "Uses tetraethyl orthosilicate (TEOS) and ozone to fill high aspect ratio Si structures with silicon dioxide (SiO2).Most modern CVD is either LPCVD or UHVCVD.", "* Classified by physical characteristics of vapor:** Aerosol assisted CVD (AACVD) – CVD in which the precursors are transported to the substrate by means of a liquid/gas aerosol, which can be generated ultrasonically.", "This technique is suitable for use with non-volatile precursors.", "** Direct liquid injection CVD (DLICVD) – CVD in which the precursors are in liquid form (liquid or solid dissolved in a convenient solvent).", "Liquid solutions are injected in a vaporization chamber towards injectors (typically car injectors).", "The precursor vapors are then transported to the substrate as in classical CVD.", "This technique is suitable for use on liquid or solid precursors.", "High growth rates can be reached using this technique.", "* Classified by type of substrate heating:** Hot wall CVD – CVD in which the chamber is heated by an external power source and the substrate is heated by radiation from the heated chamber walls.", "** Cold wall CVD – CVD in which only the substrate is directly heated either by induction or by passing current through the substrate itself or a heater in contact with the substrate.", "The chamber walls are at room temperature.", "* Plasma methods (see also Plasma processing):** Microwave plasma-assisted CVD (MPCVD)** Plasma-enhanced CVD (PECVD) – CVD that utilizes plasma to enhance chemical reaction rates of the precursors.", "PECVD processing allows deposition at lower temperatures, which is often critical in the manufacture of semiconductors.", "The lower temperatures also allow for the deposition of organic coatings, such as plasma polymers, that have been used for nanoparticle surface functionalization.", "** Remote plasma-enhanced CVD (RPECVD) – Similar to PECVD except that the wafer substrate is not directly in the plasma discharge region.", "Removing the wafer from the plasma region allows processing temperatures down to room temperature.", "** Low-energy plasma-enhanced chemical vapor deposition (LEPECVD) - CVD employing a high density, low energy plasma to obtain epitaxial deposition of semiconductor materials at high rates and low temperatures.", "* Atomic-layer CVD (ALCVD) – Deposits successive layers of different substances to produce layered, crystalline films.", "See Atomic layer epitaxy.", "* Combustion chemical vapor deposition (CCVD) – Combustion Chemical Vapor Deposition or flame pyrolysis is an open-atmosphere, flame-based technique for depositing high-quality thin films and nanomaterials.", "* Hot filament CVD (HFCVD) – also known as catalytic CVD (Cat-CVD) or more commonly, initiated CVD, this process uses a hot filament to chemically decompose the source gases.", "The filament temperature and substrate temperature thus are independently controlled, allowing colder temperatures for better absorption rates at the substrate and higher temperatures necessary for decomposition of precursors to free radicals at the filament.", "* Hybrid physical-chemical vapor deposition (HPCVD) – This process involves both chemical decomposition of precursor gas and vaporization of a solid source.", "* Metalorganic chemical vapor deposition (MOCVD) – This CVD process is based on metalorganic precursors.", "* Rapid thermal CVD (RTCVD) – This CVD process uses heating lamps or other methods to rapidly heat the wafer substrate.", "Heating only the substrate rather than the gas or chamber walls helps reduce unwanted gas-phase reactions that can lead to particle formation.", "* Vapor-phase epitaxy (VPE)* Photo-initiated CVD (PICVD) – This process uses UV light to stimulate chemical reactions.", "It is similar to plasma processing, given that plasmas are strong emitters of UV radiation.", "Under certain conditions, PICVD can be operated at or near atmospheric pressure.", "* Laser chemical vapor deposition (LCVD) - This CVD process uses lasers to heat spots or lines on a substrate in semiconductor applications.", "In MEMS and in fiber production the lasers are used rapidly to break down the precursor gas—process temperature can exceed 2000 °C—to build up a solid structure in much the same way as laser sintering based 3-D printers build up solids from powders." ], [ "Uses", "CVD is commonly used to deposit conformal films and augment substrate surfaces in ways that more traditional surface modification techniques are not capable of.", "CVD is extremely useful in the process of atomic layer deposition at depositing extremely thin layers of material.", "A variety of applications for such films exist.", "Gallium arsenide is used in some integrated circuits (ICs) and photovoltaic devices.", "Amorphous polysilicon is used in photovoltaic devices.", "Certain carbides and nitrides confer wear-resistance.", "Polymerization by CVD, perhaps the most versatile of all applications, allows for super-thin coatings which possess some very desirable qualities, such as lubricity, hydrophobicity and weather-resistance to name a few.", "The CVD of metal-organic frameworks, a class of crystalline nanoporous materials, has recently been demonstrated.", "Recently scaled up as an integrated cleanroom process depositing large-area substrates, the applications for these films are anticipated in gas sensing and low-κ dielectrics.", "CVD techniques are advantageous for membrane coatings as well, such as those in desalination or water treatment, as these coatings can be sufficiently uniform (conformal) and thin that they do not clog membrane pores." ], [ "Commercially important materials prepared by CVD", "===Polysilicon===Polycrystalline silicon is deposited from trichlorosilane (SiHCl3) or silane (SiH4), using the following reactions::SiHCl3 → Si + Cl2 + HCl:SiH4 → Si + 2 H2This reaction is usually performed in LPCVD systems, with either pure silane feedstock, or a solution of silane with 70–80% nitrogen.", "Temperatures between 600 and 650 °C and pressures between 25 and 150 Pa yield a growth rate between 10 and 20 nm per minute.", "An alternative process uses a hydrogen-based solution.", "The hydrogen reduces the growth rate, but the temperature is raised to 850 or even 1050 °C to compensate.", "Polysilicon may be grown directly with doping, if gases such as phosphine, arsine or diborane are added to the CVD chamber.", "Diborane increases the growth rate, but arsine and phosphine decrease it.=== Silicon dioxide ===Silicon dioxide (usually called simply \"oxide\" in the semiconductor industry) may be deposited by several different processes.", "Common source gases include silane and oxygen, dichlorosilane (SiCl2H2) and nitrous oxide (N2O), or tetraethylorthosilicate (TEOS; Si(OC2H5)4).", "The reactions are as follows::SiH4 + O2 → SiO2 + 2 H2:SiCl2H2 + 2 N2O → SiO2 + 2 N2 + 2 HCl:Si(OC2H5)4 → SiO2 + byproductsThe choice of source gas depends on the thermal stability of the substrate; for instance, aluminium is sensitive to high temperature.", "Silane deposits between 300 and 500 °C, dichlorosilane at around 900 °C, and TEOS between 650 and 750 °C, resulting in a layer of ''low- temperature oxide'' (LTO).", "However, silane produces a lower-quality oxide than the other methods (lower dielectric strength, for instance), and it deposits nonconformally.", "Any of these reactions may be used in LPCVD, but the silane reaction is also done in APCVD.", "CVD oxide invariably has lower quality than thermal oxide, but thermal oxidation can only be used in the earliest stages of IC manufacturing.Oxide may also be grown with impurities (alloying or \"doping\").", "This may have two purposes.", "During further process steps that occur at high temperature, the impurities may diffuse from the oxide into adjacent layers (most notably silicon) and dope them.", "Oxides containing 5–15% impurities by mass are often used for this purpose.", "In addition, silicon dioxide alloyed with phosphorus pentoxide (\"P-glass\") can be used to smooth out uneven surfaces.", "P-glass softens and reflows at temperatures above 1000 °C.", "This process requires a phosphorus concentration of at least 6%, but concentrations above 8% can corrode aluminium.", "Phosphorus is deposited from phosphine gas and oxygen::4 PH3 + 5 O2 → 2 P2O5 + 6 H2Glasses containing both boron and phosphorus (borophosphosilicate glass, BPSG) undergo viscous flow at lower temperatures; around 850 °C is achievable with glasses containing around 5 weight % of both constituents, but stability in air can be difficult to achieve.", "Phosphorus oxide in high concentrations interacts with ambient moisture to produce phosphoric acid.", "Crystals of BPO4 can also precipitate from the flowing glass on cooling; these crystals are not readily etched in the standard reactive plasmas used to pattern oxides, and will result in circuit defects in integrated circuit manufacturing.Besides these intentional impurities, CVD oxide may contain byproducts of the deposition.", "TEOS produces a relatively pure oxide, whereas silane introduces hydrogen impurities, and dichlorosilane introduces chlorine.Lower temperature deposition of silicon dioxide and doped glasses from TEOS using ozone rather than oxygen has also been explored (350 to 500 °C).", "Ozone glasses have excellent conformality but tend to be hygroscopic – that is, they absorb water from the air due to the incorporation of silanol (Si-OH) in the glass.", "Infrared spectroscopy and mechanical strain as a function of temperature are valuable diagnostic tools for diagnosing such problems.==== Silicon nitride ====Silicon nitride is often used as an insulator and chemical barrier in manufacturing ICs.", "The following two reactions deposit silicon nitride from the gas phase::3 SiH4 + 4 NH3 → Si3N4 + 12 H2:3 SiCl2H2 + 4 NH3 → Si3N4 + 6 HCl + 6 H2Silicon nitride deposited by LPCVD contains up to 8% hydrogen.", "It also experiences strong tensile stress, which may crack films thicker than 200 nm.", "However, it has higher resistivity and dielectric strength than most insulators commonly available in microfabrication (1016 Ω·cm and 10 MV/cm, respectively).Another two reactions may be used in plasma to deposit SiNH::2 SiH4 + N2 → 2 SiNH + 3 H2:SiH4 + NH3 → SiNH + 3 H2These films have much less tensile stress, but worse electrical properties (resistivity 106 to 1015 Ω·cm, and dielectric strength 1 to 5 MV/cm).=== Metals ===Tungsten CVD, used for forming conductive contacts, vias, and plugs on a semiconductor device, is achieved from tungsten hexafluoride (WF6), which may be deposited in two ways::WF6 → W + 3 F2:WF6 + 3 H2 → W + 6 HFOther metals, notably aluminium and copper, can be deposited by CVD.", ", commercially cost-effective CVD for copper did not exist, although volatile sources exist, such as Cu(hfac)2.Copper is typically deposited by electroplating.", "Aluminium can be deposited from triisobutylaluminium (TIBAL) and related organoaluminium compounds.CVD for molybdenum, tantalum, titanium, nickel is widely used.", "These metals can form useful silicides when deposited onto silicon.", "Mo, Ta and Ti are deposited by LPCVD, from their pentachlorides.", "Nickel, molybdenum, and tungsten can be deposited at low temperatures from their carbonyl precursors.", "In general, for an arbitrary metal ''M'', the chloride deposition reaction is as follows::2 MCl5 + 5 H2 → 2 M + 10 HClwhereas the carbonyl decomposition reaction can happen spontaneously under thermal treatment or acoustic cavitation and is as follows::M(CO)n → M + n COthe decomposition of metal carbonyls is often violently precipitated by moisture or air, where oxygen reacts with the metal precursor to form metal or metal oxide along with carbon dioxide.Niobium(V) oxide layers can be produced by the thermal decomposition of niobium(V) ethoxide with the loss of diethyl ether according to the equation::2 Nb(OC2H5)5 → Nb2O5 + 5 C2H5OC2H5=== Graphene ===Many variations of CVD can be utilized to synthesize graphene.", "Although many advancements have been made, the processes listed below are not commercially viable yet.", "* Carbon sourceThe most popular carbon source that is used to produce graphene is methane gas.", "One of the less popular choices is petroleum asphalt, notable for being inexpensive but more difficult to work with.Although methane is the most popular carbon source, hydrogen is required during the preparation process to promote carbon deposition on the substrate.", "If the flow ratio of methane and hydrogen are not appropriate, it will cause undesirable results.", "During the growth of graphene, the role of methane is to provide a carbon source, the role of hydrogen is to provide H atoms to corrode amorphous C, and improve the quality of graphene.", "But excessive H atoms can also corrode graphene.", "As a result, the integrity of the crystal lattice is destroyed, and the quality of graphene is deteriorated.", "Therefore, by optimizing the flow rate of methane and hydrogen gases in the growth process, the quality of graphene can be improved.", "* Use of catalystThe use of catalyst is viable in changing the physical process of graphene production.", "Notable examples include iron nanoparticles, nickel foam, and gallium vapor.", "These catalysts can either be used in situ during graphene buildup, or situated at some distance away at the deposition area.", "Some catalysts require another step to remove them from the sample material.The direct growth of high-quality, large single-crystalline domains of graphene on a dielectric substrate is of vital importance for applications in electronics and optoelectronics.", "Combining the advantages of both catalytic CVD and the ultra-flat dielectric substrate, gaseous catalyst-assisted CVD paves the way for synthesizing high-quality graphene for device applications while avoiding the transfer process.", "* Physical conditionsPhysical conditions such as surrounding pressure, temperature, carrier gas, and chamber material play a big role in production of graphene.Most systems use LPCVD with pressures ranging from 1 to 1500 Pa.", "However, some still use APCVD.", "Low pressures are used more commonly as they help prevent unwanted reactions and produce more uniform thickness of deposition on the substrate.On the other hand, temperatures used range from 800 to 1050 °C.", "High temperatures translate to an increase of the rate of reaction.", "Caution has to be exercised as high temperatures do pose higher danger levels in addition to greater energy costs.", "* Carrier gasHydrogen gas and inert gases such as argon are flowed into the system.", "These gases act as a carrier, enhancing surface reaction and improving reaction rate, thereby increasing deposition of graphene onto the substrate.", "* Chamber materialStandard quartz tubing and chambers are used in CVD of graphene.", "Quartz is chosen because it has a very high melting point and is chemically inert.", "In other words, quartz does not interfere with any physical or chemical reactions regardless of the conditions.", "* Methods of analysis of resultsRaman spectroscopy, X-ray spectroscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) are used to examine and characterize the graphene samples.Raman spectroscopy is used to characterize and identify the graphene particles; X-ray spectroscopy is used to characterize chemical states; TEM is used to provide fine details regarding the internal composition of graphene; SEM is used to examine the surface and topography.Sometimes, atomic force microscopy (AFM) is used to measure local properties such as friction and magnetism.Cold wall CVD technique can be used to study the underlying surface science involved in graphene nucleation and growth as it allows unprecedented control of process parameters like gas flow rates, temperature and pressure as demonstrated in a recent study.", "The study was carried out in a home-built vertical cold wall system utilizing resistive heating by passing direct current through the substrate.", "It provided conclusive insight into a typical surface-mediated nucleation and growth mechanism involved in two-dimensional materials grown using catalytic CVD under conditions sought out in the semiconductor industry.===Graphene nanoribbon===In spite of graphene's exciting electronic and thermal properties, it is unsuitable as a transistor for future digital devices, due to the absence of a bandgap between the conduction and valence bands.", "This makes it impossible to switch between on and off states with respect to electron flow.", "Scaling things down, graphene nanoribbons of less than 10 nm in width do exhibit electronic bandgaps and are therefore potential candidates for digital devices.", "Precise control over their dimensions, and hence electronic properties, however, represents a challenging goal, and the ribbons typically possess rough edges that are detrimental to their performance.=== Diamond ===Free-standing single-crystal CVD diamond discColorless gem cut from diamond grown by chemical vapor depositionCVD can be used to produce a synthetic diamond by creating the circumstances necessary for carbon atoms in a gas to settle on a substrate in crystalline form.", "CVD of diamonds has received much attention in the materials sciences because it allows many new applications that had previously been considered too expensive.", "CVD diamond growth typically occurs under low pressure (1–27 kPa; 0.145–3.926 psi; 7.5–203 Torr) and involves feeding varying amounts of gases into a chamber, energizing them and providing conditions for diamond growth on the substrate.", "The gases always include a carbon source, and typically include hydrogen as well, though the amounts used vary greatly depending on the type of diamond being grown.", "Energy sources include hot filament, microwave power, and arc discharges, among others.", "The energy source is intended to generate a plasma in which the gases are broken down and more complex chemistries occur.", "The actual chemical process for diamond growth is still under study and is complicated by the very wide variety of diamond growth processes used.Using CVD, films of diamond can be grown over large areas of substrate with control over the properties of the diamond produced.", "In the past, when high pressure high temperature (HPHT) techniques were used to produce a diamond, the result was typically very small free-standing diamonds of varying sizes.", "With CVD diamond, growth areas of greater than fifteen centimeters (six inches) in diameter have been achieved, and much larger areas are likely to be successfully coated with diamond in the future.", "Improving this process is key to enabling several important applications.The growth of diamond directly on a substrate allows the addition of many of diamond's important qualities to other materials.", "Since diamond has the highest thermal conductivity of any bulk material, layering diamond onto high heat-producing electronics (such as optics and transistors) allows the diamond to be used as a heat sink.", "Diamond films are being grown on valve rings, cutting tools, and other objects that benefit from diamond's hardness and exceedingly low wear rate.", "In each case the diamond growth must be carefully done to achieve the necessary adhesion onto the substrate.", "Diamond's very high scratch resistance and thermal conductivity, combined with a lower coefficient of thermal expansion than Pyrex glass, a coefficient of friction close to that of Teflon (polytetrafluoroethylene) and strong lipophilicity would make it a nearly ideal non-stick coating for cookware if large substrate areas could be coated economically.CVD growth allows one to control the properties of the diamond produced.", "In the area of diamond growth, the word \"diamond\" is used as a description of any material primarily made up of sp3-bonded carbon, and there are many different types of diamond included in this.", "By regulating the processing parameters—especially the gases introduced, but also including the pressure the system is operated under, the temperature of the diamond, and the method of generating plasma—many different materials that can be considered diamond can be made.", "Single-crystal diamond can be made containing various dopants.", "Polycrystalline diamond consisting of grain sizes from several nanometers to several micrometers can be grown.", "Some polycrystalline diamond grains are surrounded by thin, non-diamond carbon, while others are not.", "These different factors affect the diamond's hardness, smoothness, conductivity, optical properties and more." ], [ "Chalcogenides", "Commercially, mercury cadmium telluride is of continuing interest for detection of infrared radiation.", "Consisting of an alloy of CdTe and HgTe, this material can be prepared from the dimethyl derivatives of the respective elements." ], [ "See also", "* Apollo Diamond* Bubbler cylinder* Carbonyl metallurgy* Electrostatic spray assisted vapour deposition* Element Six* Ion plating* Metalorganic vapour phase epitaxy* Virtual metrology* Lisa McElwee-White* List of metal-organic chemical vapour deposition precursors* List of synthetic diamond manufacturers" ], [ "References" ], [ "Further reading", "* * * * Okada K. (2007).", "\"Plasma-enhanced chemical vapor deposition of nanocrystalline diamond\" Sci.", "Technol.", "Adv.", "Mater.", "8, 624 ''free-download review''* Liu T., Raabe D. and Zaefferer S. (2008).", "\"A 3D tomographic EBSD analysis of a CVD diamond thin film\" Sci.", "Technol.", "Adv.", "Mater.", "9 (2008) 035013 ''free-download''* Wild, Christoph (2008).", "\"CVD Diamond Properties and Useful Formula\" CVD Diamond Booklet PDF ''free-download''* Hess, Dennis W. (1988).", "Chemical vapor deposition of dielectric and metal films .", "''Free-download'' from Electronic Materials and Processing: Proceedings of the First Electronic Materials and Processing Congress held in conjunction with the 1988 World Materials Congress Chicago, Illinois, USA, 24–30 September 1988, Edited by Prabjit Singh (Sponsored by the Electronic Materials and Processing Division of ASM International)." ] ]
wikipedia
[ [ "CN Tower" ], [ "Introduction", " The '''CN Tower''' () is a concrete communications and observation tower in Toronto, Ontario, Canada.", "Completed in 1976, it is located in downtown Toronto, built on the former Railway Lands.", "Its name \"CN\" referred to Canadian National, the railway company that built the tower.", "Following the railway's decision to divest non-core freight railway assets prior to the company's privatization in 1995, it transferred the tower to the Canada Lands Company, a federal Crown corporation responsible for the government's real estate portfolio.The CN Tower held the record for the world's tallest free-standing structure for 32 years, from 1975 until 2007, when it was surpassed by the Burj Khalifa, and was the world's tallest tower until 2009 when it was surpassed by the Canton Tower.", "It is currently the tenth-tallest free-standing structure in the world and remains the tallest free-standing structure on land in the Western Hemisphere.", "In 1995, the CN Tower was declared one of the modern Seven Wonders of the World by the American Society of Civil Engineers.", "It also belongs to the World Federation of Great Towers.It is a signature icon of Toronto's skyline and attracts more than two million international visitors annually.", "It houses several observation decks, a revolving restaurant at some , and an entertainment complex." ], [ "History", "CN Tower from the Toronto IslandsThe original concept of the CN Tower was first conceived in 1968 when the Canadian National Railway wanted to build a large television and radio communication platform to serve the Toronto area, and to demonstrate the strength of Canadian industry and CN in particular.", "These plans evolved over the next few years, and the project became official in 1972.The tower would have been part of Metro Centre (see CityPlace), a large development south of Front Street on the Railway Lands, a large railway switching yard that was being made redundant after the opening of the MacMillan Yard north of the city in 1965 (then known as Toronto Yard).", "Key project team members were NCK Engineering as structural engineer; John Andrews Architects; Webb, Zerafa, Menkes, Housden Architects; Foundation Building Construction; and Canron (Eastern Structural Division).As Toronto grew rapidly during the late 1960s and early 1970s, multiple skyscrapers were constructed in the downtown core, most notably First Canadian Place, which has Bank of Montreal's head offices.", "The reflective nature of the new buildings reduced the quality of broadcast signals, requiring new, higher antennas that were at least tall.", "The radio wire is estimated to be long in 44 pieces, the heaviest of which weighs around .At the time, most data communications took place over point-to-point microwave links, whose dish antennas covered the roofs of large buildings.", "As each new skyscraper was added to the downtown, former line-of-sight links were no longer possible.", "CN intended to rent \"hub\" space for microwave links, visible from almost any building in the Toronto area.The original plan for the tower envisioned a tripod consisting of three independent cylindrical \"pillars\" linked at various heights by structural bridges.", "Had it been built, this design would have been considerably shorter, with the metal antenna located roughly where the concrete section between the main level and the SkyPod lies today.", "As the design effort continued, it evolved into the current design with a single continuous hexagonal core to the SkyPod, with three support legs blended into the hexagon below the main level, forming a large Y-shape structure at the ground level.The idea for the main level in its current form evolved around this time, but the Space Deck (later renamed SkyPod) was not part of the plans until later.", "One engineer in particular felt that visitors would feel the higher observation deck would be worth paying extra for, and the costs in terms of construction were not prohibitive.", "Also around this time, it was realized that the tower could become the world's tallest free-standing structure to improve signal quality and attract tourists, and plans were changed to incorporate subtle modifications throughout the structure to this end.=== Construction ===Map of the area immediately surrounding CN TowerThe CN Tower was built by Canada Cement Company (also known as the Cement Foundation Company of Canada at the time), a subsidiary of Sweden's Skanska, a global project-development and construction group.Construction began on February 6, 1973, with massive excavations at the tower base for the foundation.", "By the time the foundation was complete, of earth and shale were removed to a depth of in the centre, and a base incorporating of concrete with of rebar and of steel cable had been built to a thickness of .", "This portion of the construction was fairly rapid, with only four months needed between the start and the foundation being ready for construction on top.To create the main support pillar, workers constructed a hydraulically raised slipform at the base.", "This was a fairly unprecedented engineering feat on its own, consisting of a large metal platform that raised itself on jacks at about per day as the concrete below set.", "Concrete was poured Monday to Friday (not continuously) by a small team of people until February 22, 1974, at which time it had already become the tallest structure in Canada, surpassing the recently built Inco Superstack in Sudbury, built using similar methods.The tower contains of concrete, all of which was mixed on-site in order to ensure batch consistency.", "Through the pour, the vertical accuracy of the tower was maintained by comparing the slip form's location to massive plumb bobs hanging from it, observed by small telescopes from the ground.", "Over the height of the tower, it varies from true vertical accuracy by only .Skycrane \"Olga\" lifting antenna segmentIn August 1974, construction of the main level commenced.", "Using 45 hydraulic jacks attached to cables strung from a temporary steel crown anchored to the top of the tower, twelve giant steel and wooden bracket forms were slowly raised, ultimately taking about a week to crawl up to their final position.", "These forms were used to create the brackets that support the main level, as well as a base for the construction of the main level itself.", "The Space Deck (currently named SkyPod) was built of concrete poured into a wooden frame attached to rebar at the lower level deck, and then reinforced with a large steel compression band around the outside.While still under construction, the CN Tower officially became the world's tallest free-standing structure on March 31, 1975.The antenna was originally to be raised by crane as well, but, during construction, the Sikorsky S-64 Skycrane helicopter became available when the United States Army sold one to civilian operators.", "The helicopter, named \"Olga\", was first used to remove the crane, and then flew the antenna up in 36 sections.The flights of the antenna pieces were a minor tourist attraction of their own, and the schedule was printed in local newspapers.", "Use of the helicopter saved months of construction time, with this phase taking only three and a half weeks instead of the planned six months.", "The tower was topped-off on April 2, 1975, after 26 months of construction, officially capturing the height record from Moscow's Ostankino Tower, and bringing the total mass to .Two years into the construction, plans for Metro Centre were scrapped, leaving the tower isolated on the Railway Lands in what was then a largely abandoned light-industrial space.", "This caused serious problems for tourists to access the tower.", "Ned Baldwin, project architect with John Andrews, wrote at the time that \"All of the logic which dictated the design of the lower accommodation has been upset,\" and that \"Under such ludicrous circumstances Canadian National would hardly have chosen this location to build.", "\"==== Phases of construction ====File:CN Tower footings 1973.jpg|Constructing the base, July 1973File:Cntower1974.jpg|Brackets being raised, August 1974File:CN Tower50 construction skycrane March 1975 01d.jpg|Helicopter lifting part of antenna, March 1975File:CN Tower under construction (April 1975).jpg|Main pod construction, April 1975File:CN Tower under construction.jpg|Nearing completion, December 1975File:CN Tower 1976.jpg|Two months after opening, August 1976=== Opening ===Financial District from the CN Tower in 2008The CN Tower opened on June 26, 1976.The construction costs of approximately ($ in dollars) were repaid in fifteen years.From the mid-1970s to the mid-1980s, the CN Tower was practically the only development along Front Street West; it was still possible to see Lake Ontario from the foot of the CN Tower due to the expansive parking lots and lack of development in the area at the time.", "As the area around the tower was developed, particularly with the completion of the Metro Toronto Convention Centre (north building) in 1984 and SkyDome in 1989 (renamed Rogers Centre in 2005), the former Railway Lands were redeveloped and the tower became the centre of a newly developing entertainment area.", "Access was greatly improved with the construction of the SkyWalk in 1989, which connected the tower and SkyDome to the nearby Union Station railway and subway station, and, in turn, to the city's Path underground pedestrian system.", "By the mid-1990s, it was the centre of a thriving tourist district.", "The entire area continues to be an area of intense building, notably a boom in condominium construction in the first quarter of the 21st century, as well as the 2013 opening of the Ripley's Aquarium by the base of the tower.===Early years ===When the CN Tower opened in 1976, there were three public observation points: the SkyPod (then known as the Space Deck) that stands at , the Indoor Observation Level (later named Indoor Lookout Level) at , and the Outdoor Observation Terrace (at the same level as the Glass Floor) at .", "One floor above the Indoor Observation Level was the Top of Toronto Restaurant, which completed a revolution once every 72 minutes.The tower would garner worldwide media attention when stuntman Dar Robinson jumped off the CN Tower on two occasions in 1979 and 1980.The first was for a scene from the movie ''Highpoint'', in which Robinson received ($ in dollars) for the stunt.", "The second was for a personal documentary.", "The first stunt had him use a parachute which he deployed three seconds before impact with the ground, while the second one used a wire decelerator attached to his back.On June 26, 1986, the tenth anniversary of the tower's opening, high-rise firefighting and rescue advocate Dan Goodwin, in a sponsored publicity event, used his hands and feet to climb the outside of the tower, a feat he performed twice on the same day.", "Following both ascents, he used multiple rappels to descend to the ground.From 1985 to 1992, the CN Tower basement level hosted the world's first flight simulator ride, Tour of the Universe.", "The ride was replaced in 1992 with a similar attraction entitled \"Space Race.\"", "It was later dismantled and replaced by two other rides in 1998 and 1999.=== The 1990s and 2000s ===A glass floor at an elevation of was installed in 1994.Canadian National Railway sold the tower to Canada Lands Company prior to privatizing the company in 1995, when it divested all operations not directly related to its core freight shipping businesses.", "The tower's name and wordmark were adjusted to remove the CN railways logo, and the tower was renamed Canada's National Tower (from Canadian National Tower), though the tower is commonly called the CN Tower.Further changes were made from 1997 to January 2004: TrizecHahn Corporation managed the tower and instituted several expansion projects including a entertainment expansion, the 1997 addition of two new elevators (to a total of six) and the consequential relocation of the staircase from the north side leg to inside the core of the building, a conversion that also added nine stairs to the climb.", "TrizecHahn also owned the Willis Tower (Sears Tower at the time) in Chicago approximately at the same time.In 2007, light-emitting diode (LED) lights replaced the incandescent lights that lit the CN Tower at night.", "This was done to take advantage of the cost savings of LED lights over incandescent lights.", "The colour of the LED lights can change, compared to the constant white colour of the incandescent lights.", "On September 12, 2007, Burj Khalifa, then under construction and known as Burj Dubai, surpassed the CN Tower as the world's tallest free-standing structure.", "In 2008, glass panels were installed in one of the CN Tower elevators, which established a world record (346 m) for highest glass floor panelled elevator in the world.=== 2010s: EdgeWalk ===EdgeWalk atop the main podOn August 1, 2011, the CN Tower opened the EdgeWalk, an amusement in which thrill-seekers can walk on and around the roof of the main pod of the tower at , which is directly above the 360 Restaurant.", "It is the world's highest full-circle, hands-free walk.", "Visitors are tethered to an overhead rail system and walk around the edge of the CN Tower's main pod above the 360 Restaurant on a metal floor.", "The attraction is closed throughout the winter and during periods of electrical storms and high winds.One of the notable guests who visited EdgeWalk was Canadian comedian Rick Mercer, featured as the first episode of the ninth season of his CBC Television news satire show, ''Rick Mercer Report''.", "There, he was accompanied by Canadian pop singer Jann Arden.", "The episode first aired on April 10, 2013.==== Pan Am Games ====The tower and surrounding areas were prominent in the 2015 Pan American Games production.", "In the opening ceremony, a pre-recorded segment featured track-and-field athlete Bruny Surin passing the flame to sprinter Donovan Bailey on the EdgeWalk and parachuting into Rogers Centre.", "A fireworks display off the tower concluded both the opening and closing ceremonies.==== Canada 150 ====On July 1, 2017, as part of the nationwide celebrations for Canada 150, which celebrated the 150th anniversary of Canadian Confederation, fireworks were once again shot from the tower in a five-minute display coordinated with the tower lights and music broadcast on a local radio station." ], [ "Closures", "*The CN Tower was closed on September 11, 2001 following the terrorist attacks on the World Trade Center.", "*The CN Tower was closed during the G20 summit on June 26–27, 2010, for security reasons, given its proximity to the Metro Toronto Convention Centre and ongoing citywide protests and riots.", "*The CN Tower was closed from 2020 to 2021 due to COVID-19 pandemic restrictions throughout Ontario.", "*The CN Tower was closed on December 16, 2021, due to glass falling off from heavy winds." ], [ "Structure", "Elevator going upView from 360 RestaurantThe CN Tower consists of several substructures.", "The main portion of the tower is a hollow concrete hexagonal pillar containing the stairwells and power and plumbing connections.", "The tower's six elevators are located in the three inverted angles created by the Tower's hexagonal shape (two elevators per angle).", "Each of the three elevator shafts is lined with glass, allowing for views of the city as the glass-windowed elevators make their way through the tower.", "The stairwell was originally located in one of these angles (the one facing north), but was moved into the central hollow of the tower; the tower's new fifth and sixth elevators were placed in the hexagonal angle that once contained the stairwell.", "On top of the main concrete portion of the tower is a tall metal broadcast antenna, carrying television and radio signals.", "There are three visitor areas: the Glass Floor and Outdoor Observation Terrace, which are both located at an elevation of , the Indoor Lookout Level (formerly known as \"Indoor Observation Level\") located at , and the higher SkyPod (formerly known as \"Space Deck\") at , just below the metal antenna.", "The hexagonal shape is visible between the two highest areas; however, below the main deck, three large supporting legs give the tower the appearance of a large tripod.The main deck level has seven storeys, some of which are open to the public.", "Below the public areas—at —is a large white donut-shaped radome containing the structure's UHF transmitters.", "The glass floor and outdoor observation deck are at .", "The glass floor has an area of and can withstand a pressure of .", "The floor's thermal glass units are thick, consisting of a pane of laminated glass, airspace and a pane of laminated glass.", "In 2008, one elevator was upgraded to add a glass floor panel, believed to have the highest vertical rise of any elevator equipped with this feature.", "The Horizons Cafe and the lookout level are at .", "The 360 Restaurant, a revolving restaurant that completes a full rotation once every 72 minutes, is at .", "When the tower first opened, it also featured a disco named Sparkles (at the Indoor Observation Level), billed as the highest disco and dance floor in the world.The SkyPod was once the highest public observation deck in the world until it was surpassed by the Shanghai World Financial Center in 2008.A metal staircase reaches the main deck level after 1,776 steps, and the SkyPod above after 2,579 steps; it is the tallest metal staircase on Earth.", "These stairs are intended for emergency use only except for charity stair-climb events two times during the year.", "The average climber takes approximately 30 minutes to climb to the base of the radome, but the fastest climb on record is 7 minutes and 52 seconds in 1989 by Brendan Keenoy, an Ontario Provincial Police officer.", "In 2002, Canadian Olympian and Paralympic champion Jeff Adams climbed the stairs of the tower in a specially designed wheelchair.", "The stairs were originally on one of the three sides of the tower (facing north), with a glass view, but these were later replaced with the third elevator pair and the stairs were moved to the inside of the core.", "Top climbs on the new, windowless stairwell used since around 2003 have generally been over ten minutes.File:CN Tower, Toronto, Ontario (29969151776).jpg|Inside 360 RestaurantFile:CN Tower Main Observation Level 2023.jpg|Main Observation Level after renovation in 2018File:CN Tower Turmkorb-Modell-blau.png|Cross-section of Main PodFile:Inside the skypod of the CN Tower (27287339323).jpg|SkypodFile:CN Tower Terrace Level after renovation in 2023.jpg|Terrace Level glass floorFile:CNTowerNastyFall.jpg|View through glass floorFile:CN Tower Gift Shop after renovation 2023.jpg|Gift shop in 2023File:CN Tower Ground View Looking Up.png|Ground view looking up at the CN Tower.=== Architects ===*WZMH Architects*John Hamilton Andrews*Webb Zerafa*Menkes Housden with the help of Edward R. Baldwin=== Falling ice danger ===Looking east at CN Tower from Gardiner Expressway in 2010A freezing rain storm on March 2, 2007, resulted in a layer of ice several centimetres thick forming on the side of the tower and other downtown buildings.", "The sun thawed the ice, then winds of up to blew some of it away from the structure.", "There were fears that cars and windows of nearby buildings would be smashed by large chunks of ice.", "In response, police closed some streets surrounding the tower.", "During morning rush hour on March 5 of the same year, police expanded the area of closed streets to include the Gardiner Expressway away from the tower as increased winds blew the ice farther, as far north as King Street West, away, where a taxicab window was shattered.", "Subsequently, on March 6, 2007, the Gardiner Expressway reopened after winds abated.On April 16, 2018, falling ice from the CN Tower punctured the roof of the nearby Rogers Centre stadium, causing the Toronto Blue Jays to postpone the game that day to the following day as a doubleheader; this was the third doubleheader held at the Rogers Centre.", "On April 20 of the same year, the CN Tower reopened.=== Safety features ===In August 2000, a fire broke out at the Ostankino Tower in Moscow, killing three people and causing extensive damage.", "The fire was blamed on poor maintenance and outdated equipment.", "The failure of the fire-suppression systems and the lack of proper equipment for firefighters allowed the fire to destroy most of the interior and sparked fears the tower might even collapse.The Ostankino Tower was completed nine years before the CN Tower and is only shorter.", "The parallels between the towers led to some concern that the CN Tower could be at risk of a similar tragedy.", "However, Canadian officials subsequently stated that it is \"highly unlikely\" that a similar disaster could occur at the CN Tower, as it has important safeguards that were not present in the Ostankino Tower.", "Specifically, officials cited:* the fireproof building materials used in the tower's construction,* frequent and stringent safety inspections,* an extensive sprinkler system,* a 24-hour emergency monitoring operation,* two 68,160-litre (15,000-imperial gallon; 18,006-US gallon) water reservoirs at the top, which are automatically replenished,* a fire hose at the base of the structure capable of sending to any location in the tower,* a ban on natural gas appliances anywhere in the tower (including the restaurant in the main pod),* an elevator that can be used during a fire as it runs up the outside of the building and can be powered by three emergency generators at the base of the structure (unlike the elevator at the Ostankino Tower, which malfunctioned).Officials also noted that the CN Tower has an excellent safety record, although there was an electrical fire in the antennas on August 16, 2017 — the tower's first fire.", "Moreover, other supertall structures built between 1967 and 1976 — such as the Willis Tower (formerly the Sears Tower), the World Trade Center (until its destruction on September 11, 2001), the Fernsehturm Berlin, the Aon Center, 875 North Michigan Avenue (formerly the John Hancock Center), and First Canadian Place — also have excellent safety records, which suggests that the Ostankino Tower accident was a rare safety failure, and that the likelihood of similar events occurring at other supertall structures is extremely low." ], [ "Lighting", "Illuminated in the colours of the Flag of France following the November 2015 Paris attacksThe CN Tower was originally lit at night with incandescent lights, which were removed in 1997 because they were inefficient and expensive to repair.", "In June 2007, the tower was outfitted with 1,330 super-bright LED lights inside the elevator shafts, shooting over the main pod and upward to the top of the tower's mast to light the tower from dusk until 2 a.m.", "The official opening ceremony took place on June 28, 2007, before the Canada Day holiday weekend.The tower changes its lighting scheme on holidays and to commemorate major events.", "After the 95th Grey Cup in Toronto, the tower was lit in green and white to represent the colours of the Grey Cup champion Saskatchewan Roughriders.", "From sundown on August 27, 2011, to sunrise the following day, the tower was lit in orange, the official colour of the New Democratic Party (NDP), to commemorate the death of federal NDP leader and leader of the official opposition Jack Layton.", "When former South African president Nelson Mandela died, the tower was lit in the colours of the South African flag.", "When former federal finance minister under Stephen Harper's Conservatives Jim Flaherty died, the tower was lit in green to reflect his Irish Canadian heritage.", "On the night of the attacks on Paris on November 13, 2015, the tower displayed the colours of the French flag.", "On June 8, 2021, the tower displayed the colours of the Toronto Maple Leafs' archrivals Montreal Canadiens after they advanced to the semifinals of 2021 Stanley Cup playoffs.", "The CN Tower was lit in the colours of the Ukrainian flag during the beginning of the Russian invasion of Ukraine in late February 2022.Programmed remotely from a desktop computer with a wireless network interface controller in Burlington, Ontario, the LEDs use less energy to light than the previous incandescent lights (10% less energy than the dimly lit version and 60% less than the brightly lit version).", "The estimated cost to use the LEDs is $1,000 per month.During the spring and autumn bird migration seasons, the lights are turned off to comply with the voluntary Fatal Light Awareness Program, which \"encourages buildings to dim unnecessary exterior lighting to mitigate bird mortality during spring and summer migration.\"", "Date Colour Occasion Ongoing Red and White Top of the hour CN Tower light show January 26 Light Blue and Yellow World Alzheimer Day February 4 Orange and Blue World Cancer Day February 14 Red Valentine's Day March 17 Green Saint Patrick's Day March 21–June 20 Decreased Lighting Bird Migration - Lighting is decreased during spring bird migration September 23–December 20 Decreased Lighting Bird Migration - Lighting is decreased during autumn bird migration December Red and Green Season's Greetings December 1 Red World AIDS Day December 6 Purple White Ribbon Day December 10 Yellow Human Rights Day December 21 Blue and White First Day of Winter December 31 Countdown to and Light Show New Year's Eve" ], [ "Height comparisons", "View from base• Burj Khalifa, Dubai• CN Tower, Toronto• Willis Tower, ChicagoThe CN Tower is the tallest freestanding structure in the Western Hemisphere.", "As of 2013, there were two other freestanding structures in the Western Hemisphere exceeding in height: the Willis Tower in Chicago, which stands at when measured to its pinnacle, and One World Trade Center in New York City, which has a pinnacle height of , or approximately shorter than the CN Tower.", "Due to the symbolism of the number 1776 (the year of the signing of the United States Declaration of Independence), the height of One World Trade Center is unlikely to be increased.", "The proposed Chicago Spire was expected to exceed the height of the CN Tower, but its construction was halted early due to financial difficulties amid the Great Recession, and was eventually cancelled in 2010.=== Height distinction debate ======= \"World's Tallest Tower\" title ====''Guinness World Records'' has called the CN Tower \"the world's tallest self-supporting tower\" and \"the world's tallest free-standing tower\".", "Although Guinness did list this description of the CN Tower under the heading \"tallest building\" at least once, it has also listed it under \"tallest tower\", omitting it from its list of \"tallest buildings.\"", "In 1996, Guinness changed the tower's classification to \"World's Tallest Building and Freestanding Structure\".", "Emporis and the Council on Tall Buildings and Urban Habitat both listed the CN Tower as the world's tallest free-standing structure on land, and specifically state that the CN Tower is not a true building, thereby awarding the title of world's tallest building to Taipei 101, which is shorter than the CN Tower.", "The issue of what was tallest became moot when Burj Khalifa, then under construction, exceeded the height of the CN Tower in 2007 (see below).Although the CN Tower contains a restaurant, a gift shop and multiple observation levels, it does not have floors continuously from the ground, and therefore it is not considered a building by the Council on Tall Buildings and Urban Habitat (CTBUH) or Emporis.", "CTBUH defines a building as \"a structure that is designed for residential, business, or manufacturing purposes.", "An essential characteristic of a building is that it has floors.\"", "The CN Tower and other similar structures—such as the Ostankino Tower in Moscow, Russia; the Oriental Pearl Tower in Shanghai, China; The Strat in Las Vegas, Nevada, United States; and the Eiffel Tower in Paris, France—are categorized as \"towers\", which are free-standing structures that may have observation decks and a few other habitable levels, but do not have floors from the ground up.", "The CN Tower was the tallest tower by this definition until 2010 (see below).Taller than the CN Tower are numerous radio masts and towers, which are held in place by guy-wires, the tallest being the KVLY-TV mast in Blanchard, North Dakota, in the United States at tall, leading to a distinction between these and \"free-standing\" structures.", "Additionally, the Petronius Platform stands above its base on the bottom of the Gulf of Mexico near the Mississippi River Delta, but only the top of this oil and natural gas platform are above water, and the structure is thus partially supported by its buoyancy.", "Like the CN Tower, none of these taller structures are commonly considered buildings.On September 12, 2007, Burj Khalifa, which is a hotel, residential and commercial building in Dubai, United Arab Emirates (formerly known as Burj Dubai before opening), passed the CN Tower's 553.33-m height.", "The CN Tower held the record of the tallest freestanding structure on land for over 30 years.After Burj Khalifa had been formally recognized by the Guinness World Records as the world's tallest freestanding structure, Guinness re-certified CN Tower as the world's tallest freestanding tower.", "The tower definition used by Guinness was defined by the Council on Tall Buildings and Urban Habitat as 'a building in which less than 50% of the construction is usable floor space'.", "''Guinness World Records'' editor-in-chief Craig Glenday announced that Burj Khalifa was not classified as a tower because it has too much usable floor space to be considered to be a tower.", "CN Tower still held world records for highest above ground wine cellar (in 360 Restaurant) at 351 m, highest above ground restaurant at 346 m (Horizons Restaurant), and tallest free-standing concrete tower during Guinness's recertification.", "The CN Tower was surpassed in 2009 by the Canton Tower in Guangzhou, China, which stands at tall, as the world's tallest tower; which in turn was surpassed by the Tokyo Skytree in 2011, which currently is the tallest tower at in height.", "The CN Tower, as of 2022, stands as the tenth-tallest free-standing structure on land, remains the tallest free-standing structure in the Western Hemisphere, and is the third-tallest tower.==== Height records ====View from interior of Rogers CentreSince its construction, the tower has gained the following world height records:RecordOwnerValueTime periodSucceeded byWorld's tallest free-standing structureMarch 31, 1975 to September 12, 2007Burj KhalifaWorld's tallest tower1975 to 2009Canton TowerWorld's highest public observation galleryWorld's highest glass floor panelled elevator2008 to present—World's longest metal staircaseCN TowerWorld's highest glass floor2008 to July 2, 2009Willis TowerWorld's highest and largest revolving restaurantWorld's highest barSeptember 21, 2009 to present—World's highest wine cellar" ], [ "Use", "Main Pod and broadcast antennasThe CN Tower has been and continues to be used as a communications tower for a number of different media and by numerous companies.=== Television broadcasters ===VHFUHFVirtualCallsignAffiliationBranding9—9.1CFTO-DTCTVCTV Toronto—1919.1CICA-DTTVOTVO—205.1CBLT-DTCBC TelevisionCBC Toronto—2525.1CBLFT-DTIci Radio-Canada TéléICI Ontario—4040.1CJMT-DTOmni TelevisionOmni.2—4141.1CIII-DT-41GlobalGlobal Toronto—4457.1CITY-DTCitytvCitytv Toronto—4747.1CFMT-DTOmni TelevisionOmni.1'''Source''': Vividcomm=== Radio ===There is no AM broadcasting from the CN Tower.", "The FM transmitters are situated in a metal broadcast antenna, on top of the main concrete portion of the tower at an elevation above .FrequencykWCallsignAffiliation/OwnerBrandingNotes91.1 MHz40CJRTIndependent; PublicJAZZ.FM91Jazz94.1 MHz38CBLCanadian Broadcasting CorporationCBC MusicNon-commercial; classical; jazz97.3 MHz28.9CHBMStingray Groupboom 97.3Classic hits98.1 MHz44CHFIRogers Sports & Media98.1 CHFIAdult contemporary99.9 MHz40CKFMBell MediaVirgin Radio 99.9FMTop 40/Contemporary hits100.7 MHz4CHINCHIN Radio/TV InternationalCHIN RadioPrimarily in Italian and Portuguese102.1 MHz35CFNYCorus Entertainment102.1 the EdgeAlternative rock104.5 MHz40CHUMBell Media104.5 CHUM FMHot adult contemporary107.1 MHz40CILQCorus EntertainmentClassic Rock Q 107Mainstream rock'''Source''': Vividcomm=== Communications ===* Bell Canada* Toronto Transit Commission* Amateur radio repeaters \"2-Tango\" (VHF) and \"4-Tango\" (440/70 cm UHF)—owned and operated by the Toronto FM Communications Society, under callsign VE3TWR" ], [ "In popular culture", "The CN Tower has been featured in numerous films, television shows, music recording covers, and video games.", "The tower also has its own official mascot, which resembles the tower itself.", "*''Highpoint'' is a Canadian 1982 action film starring Richard Harris, Christopher Plummer and Beverly D'Angelo.", "It features a shot of stuntman Dar Robinson jumping off of the CN Tower in 1979.", "*''Views'' is a 2016 studio album released on April 29, 2016 by Canadian rapper Drake.", "The cover artwork features Drake sitting atop the CN Tower in Toronto.", "Drake appeared significantly larger than life-size on the cover, and the CN Tower's Twitter account later confirmed it to be photo edited." ], [ "See also", "* Architecture of Toronto* List of tallest buildings in Toronto* List of tallest structures in Canada* List of tallest freestanding structures* List of tallest towers* List of tallest buildings and structures* List of tallest structures" ], [ "References" ], [ "External links", "* * CBC Archives – CN Tower opens to the public.", "(Multimedia)* Edgewalk* The Design, Engineering and Construction of the CN Tower – 1972 through to 1976* A visual construction history of the CN Tower – at 40th year anniversaries* How the CN Tower was Built - Art Of Engineering (YouTube documentary)" ] ]
wikipedia
[ [ "Chain rule" ], [ "Introduction", "In calculus, the '''chain rule''' is a formula that expresses the derivative of the composition of two differentiable functions and in terms of the derivatives of and .", "More precisely, if is the function such that for every , then the chain rule is, in Lagrange's notation,:or, equivalently,:The chain rule may also be expressed in Leibniz's notation.", "If a variable depends on the variable , which itself depends on the variable (that is, and are dependent variables), then depends on as well, via the intermediate variable .", "In this case, the chain rule is expressed as: and:for indicating at which points the derivatives have to be evaluated.In integration, the counterpart to the chain rule is the substitution rule." ], [ "Intuitive explanation", "Intuitively, the chain rule states that knowing the instantaneous rate of change of relative to and that of relative to allows one to calculate the instantaneous rate of change of relative to as the product of the two rates of change.", "As put by George F. Simmons: \"If a car travels twice as fast as a bicycle and the bicycle is four times as fast as a walking man, then the car travels 2 × 4 = 8 times as fast as the man.\"", "The relationship between this example and the chain rule is as follows.", "Let , and be the (variable) positions of the car, the bicycle, and the walking man, respectively.", "The rate of change of relative positions of the car and the bicycle is Similarly, So, the rate of change of the relative positions of the car and the walking man is:The rate of change of positions is the ratio of the speeds, and the speed is the derivative of the position with respect to the time; that is,:or, equivalently,:which is also an application of the chain rule." ], [ "History", "The chain rule seems to have first been used by Gottfried Wilhelm Leibniz.", "He used it to calculate the derivative of as the composite of the square root function and the function .", "He first mentioned it in a 1676 memoir (with a sign error in the calculation).", "The common notation of the chain rule is due to Leibniz.", "Guillaume de l'Hôpital used the chain rule implicitly in his ''Analyse des infiniment petits''.", "The chain rule does not appear in any of Leonhard Euler's analysis books, even though they were written over a hundred years after Leibniz's discovery..", "It is believed that the first \"modern\" version of the chain rule appears in Lagrange’s 1797 ''Théorie des fonctions analytiques''; it also appears in Cauchy’s 1823 ''Résumé des Leçons données a L’École Royale Polytechnique sur Le Calcul Infinitesimal''." ], [ "Statement", "The simplest form of the chain rule is for real-valued functions of one real variable.", "It states that if '''' is a function that is differentiable at a point '''' (i.e.", "the derivative exists) and '''' is a function that is differentiable at , then the composite function is differentiable at '''', and the derivative is:The rule is sometimes abbreviated as:If and , then this abbreviated form is written in Leibniz notation as::The points where the derivatives are evaluated may also be stated explicitly::Carrying the same reasoning further, given '''' functions with the composite function , if each function is differentiable at its immediate input, then the composite function is also differentiable by the repeated application of Chain Rule, where the derivative is (in Leibniz's notation)::" ], [ "Applications", "=== Composites of more than two functions ===The chain rule can be applied to composites of more than two functions.", "To take the derivative of a composite of more than two functions, notice that the composite of , , and '''' (in that order) is the composite of with .", "The chain rule states that to compute the derivative of , it is sufficient to compute the derivative of '''' and the derivative of .", "The derivative of '''' can be calculated directly, and the derivative of can be calculated by applying the chain rule again.For concreteness, consider the function:This can be decomposed as the composite of three functions::So that .Their derivatives are::The chain rule states that the derivative of their composite at the point is:: In Leibniz's notation, this is::or for short,:The derivative function is therefore::Another way of computing this derivative is to view the composite function as the composite of and ''h''.", "Applying the chain rule in this manner would yield::This is the same as what was computed above.", "This should be expected because .Sometimes, it is necessary to differentiate an arbitrarily long composition of the form .", "In this case, define:where and when .", "Then the chain rule takes the form:or, in the Lagrange notation,:=== Quotient rule ===The chain rule can be used to derive some well-known differentiation rules.", "For example, the quotient rule is a consequence of the chain rule and the product rule.", "To see this, write the function as the product .", "First apply the product rule::To compute the derivative of , notice that it is the composite of with the reciprocal function, that is, the function that sends to .", "The derivative of the reciprocal function is .", "By applying the chain rule, the last expression becomes::which is the usual formula for the quotient rule.=== Derivatives of inverse functions ===Suppose that has an inverse function.", "Call its inverse function so that we have .", "There is a formula for the derivative of in terms of the derivative of .", "To see this, note that and satisfy the formula:And because the functions and are equal, their derivatives must be equal.", "The derivative of is the constant function with value 1, and the derivative of is determined by the chain rule.", "Therefore, we have that::To express as a function of an independent variable , we substitute for wherever it appears.", "Then we can solve for .", ":For example, consider the function .", "It has an inverse .", "Because , the above formula says that:This formula is true whenever is differentiable and its inverse is also differentiable.", "This formula can fail when one of these conditions is not true.", "For example, consider .", "Its inverse is , which is not differentiable at zero.", "If we attempt to use the above formula to compute the derivative of at zero, then we must evaluate .", "Since and , we must evaluate 1/0, which is undefined.", "Therefore, the formula fails in this case.", "This is not surprising because is not differentiable at zero." ], [ "Higher derivatives", "Faà di Bruno's formula generalizes the chain rule to higher derivatives.", "Assuming that and , then the first few derivatives are::" ], [ "Proofs", "=== First proof ===One proof of the chain rule begins by defining the derivative of the composite function , where we take the limit of the difference quotient for as approaches ::Assume for the moment that does not equal for any near .", "Then the previous expression is equal to the product of two factors::If oscillates near , then it might happen that no matter how close one gets to , there is always an even closer such that .", "For example, this happens near for the continuous function defined by for and otherwise.", "Whenever this happens, the above expression is undefined because it involves division by zero.", "To work around this, introduce a function as follows::We will show that the difference quotient for is always equal to::Whenever is not equal to , this is clear because the factors of cancel.", "When equals , then the difference quotient for is zero because equals , and the above product is zero because it equals times zero.", "So the above product is always equal to the difference quotient, and to show that the derivative of at exists and to determine its value, we need only show that the limit as goes to of the above product exists and determine its value.To do this, recall that the limit of a product exists if the limits of its factors exist.", "When this happens, the limit of the product of these two factors will equal the product of the limits of the factors.", "The two factors are and .", "The latter is the difference quotient for at , and because is differentiable at by assumption, its limit as tends to exists and equals .As for , notice that is defined wherever '''' is.", "Furthermore, '''' is differentiable at by assumption, so is continuous at , by definition of the derivative.", "The function is continuous at because it is differentiable at , and therefore is continuous at .", "So its limit as '''' goes to '''' exists and equals , which is .This shows that the limits of both factors exist and that they equal and , respectively.", "Therefore, the derivative of at ''a'' exists and equals .=== Second proof ===Another way of proving the chain rule is to measure the error in the linear approximation determined by the derivative.", "This proof has the advantage that it generalizes to several variables.", "It relies on the following equivalent definition of differentiability at a point: A function ''g'' is differentiable at ''a'' if there exists a real number ''g''′(''a'') and a function ''ε''(''h'') that tends to zero as ''h'' tends to zero, and furthermore:Here the left-hand side represents the true difference between the value of ''g'' at ''a'' and at , whereas the right-hand side represents the approximation determined by the derivative plus an error term.In the situation of the chain rule, such a function ''ε'' exists because ''g'' is assumed to be differentiable at ''a''.", "Again by assumption, a similar function also exists for ''f'' at ''g''(''a'').", "Calling this function ''η'', we have:The above definition imposes no constraints on ''η''(0), even though it is assumed that ''η''(''k'') tends to zero as ''k'' tends to zero.", "If we set , then ''η'' is continuous at 0.Proving the theorem requires studying the difference as ''h'' tends to zero.", "The first step is to substitute for using the definition of differentiability of ''g'' at ''a''::The next step is to use the definition of differentiability of ''f'' at ''g''(''a'').", "This requires a term of the form for some ''k''.", "In the above equation, the correct ''k'' varies with ''h''.", "Set and the right hand side becomes .", "Applying the definition of the derivative gives::To study the behavior of this expression as ''h'' tends to zero, expand ''k''''h''.", "After regrouping the terms, the right-hand side becomes::Because ''ε''(''h'') and ''η''(''k''''h'') tend to zero as ''h'' tends to zero, the first two bracketed terms tend to zero as ''h'' tends to zero.", "Applying the same theorem on products of limits as in the first proof, the third bracketed term also tends zero.", "Because the above expression is equal to the difference , by the definition of the derivative is differentiable at ''a'' and its derivative is The role of ''Q'' in the first proof is played by ''η'' in this proof.", "They are related by the equation::The need to define ''Q'' at ''g''(''a'') is analogous to the need to define ''η'' at zero.=== Third proof ===Constantin Carathéodory's alternative definition of the differentiability of a function can be used to give an elegant proof of the chain rule.Under this definition, a function is differentiable at a point if and only if there is a function , continuous at and such that .", "There is at most one such function, and if is differentiable at then .Given the assumptions of the chain rule and the fact that differentiable functions and compositions of continuous functions are continuous, we have that there exist functions , continuous at , and , continuous at , and such that,:and:Therefore,:but the function given by is continuous at , and we get, for this :A similar approach works for continuously differentiable (vector-)functions of many variables.", "This method of factoring also allows a unified approach to stronger forms of differentiability, when the derivative is required to be Lipschitz continuous, Hölder continuous, etc.", "Differentiation itself can be viewed as the polynomial remainder theorem (the little Bézout theorem, or factor theorem), generalized to an appropriate class of functions.", "=== Proof via infinitesimals ===If and then choosing infinitesimal we compute the corresponding and then the corresponding , so that:and applying the standard part we obtain:which is the chain rule." ], [ "Multivariable case", "The full generalization of the chain rule to multi-variable functions (such as ) is rather technical.", "However, it is simpler to write in the case of functions of the form where , and for each As this case occurs often in the study of functions of a single variable, it is worth describing it separately.===Case of scalar-valued functions with multiple inputs===Let , and for each To write the chain rule for the composition of functions one needs the partial derivatives of with respect to its arguments.", "The usual notations for partial derivatives involve names for the arguments of the function.", "As these arguments are not named in the above formula, it is simpler and clearer to use ''D''-Notation, and to denote by : the partial derivative of with respect to its th argument, and by : the value of this derivative at .With this notation, the chain rule is:====Example: arithmetic operations====If the function is addition, that is, if :then and .", "Thus, the chain rule gives :For multiplication:the partials are and .", "Thus, :The case of exponentiation:is slightly more complicated, as :and, as :It follows that :===General rule: Vector-valued functions with multiple inputs===The simplest way for writing the chain rule in the general case is to use the total derivative, which is a linear transformation that captures all directional derivatives in a single formula.", "Consider differentiable functions and , and a point in .", "Let denote the total derivative of at and denote the total derivative of at .", "These two derivatives are linear transformations and , respectively, so they can be composed.", "The chain rule for total derivatives is that their composite is the total derivative of at ::or for short,:The higher-dimensional chain rule can be proved using a technique similar to the second proof given above.Because the total derivative is a linear transformation, the functions appearing in the formula can be rewritten as matrices.", "The matrix corresponding to a total derivative is called a Jacobian matrix, and the composite of two derivatives corresponds to the product of their Jacobian matrices.", "From this perspective the chain rule therefore says::or for short,:That is, the Jacobian of a composite function is the product of the Jacobians of the composed functions (evaluated at the appropriate points).The higher-dimensional chain rule is a generalization of the one-dimensional chain rule.", "If ''k'', ''m'', and ''n'' are 1, so that and , then the Jacobian matrices of ''f'' and ''g'' are .", "Specifically, they are::The Jacobian of ''f'' ∘ ''g'' is the product of these matrices, so it is , as expected from the one-dimensional chain rule.", "In the language of linear transformations, ''D''''a''(''g'') is the function which scales a vector by a factor of ''g''′(''a'') and ''D''''g''(''a'')(''f'') is the function which scales a vector by a factor of ''f''′(''g''(''a'')).", "The chain rule says that the composite of these two linear transformations is the linear transformation , and therefore it is the function that scales a vector by ''f''′(''g''(''a''))⋅''g''′(''a'').Another way of writing the chain rule is used when ''f'' and ''g'' are expressed in terms of their components as and .", "In this case, the above rule for Jacobian matrices is usually written as::The chain rule for total derivatives implies a chain rule for partial derivatives.", "Recall that when the total derivative exists, the partial derivative in the ''i''th coordinate direction is found by multiplying the Jacobian matrix by the ''i''th basis vector.", "By doing this to the formula above, we find::Since the entries of the Jacobian matrix are partial derivatives, we may simplify the above formula to get::More conceptually, this rule expresses the fact that a change in the ''x''''i'' direction may change all of ''g''1 through ''gm'', and any of these changes may affect ''f''.In the special case where , so that ''f'' is a real-valued function, then this formula simplifies even further::This can be rewritten as a dot product.", "Recalling that , the partial derivative is also a vector, and the chain rule says that::==== Example ====Given where and , determine the value of and using the chain rule.", ":and:==== Higher derivatives of multivariable functions ====Faà di Bruno's formula for higher-order derivatives of single-variable functions generalizes to the multivariable case.", "If is a function of as above, then the second derivative of is::" ], [ "Further generalizations", "All extensions of calculus have a chain rule.", "In most of these, the formula remains the same, though the meaning of that formula may be vastly different.One generalization is to manifolds.", "In this situation, the chain rule represents the fact that the derivative of is the composite of the derivative of ''f'' and the derivative of ''g''.", "This theorem is an immediate consequence of the higher dimensional chain rule given above, and it has exactly the same formula.The chain rule is also valid for Fréchet derivatives in Banach spaces.", "The same formula holds as before.", "This case and the previous one admit a simultaneous generalization to Banach manifolds.In differential algebra, the derivative is interpreted as a morphism of modules of Kähler differentials.", "A ring homomorphism of commutative rings determines a morphism of Kähler differentials which sends an element ''dr'' to ''d''(''f''(''r'')), the exterior differential of ''f''(''r'').", "The formula holds in this context as well.The common feature of these examples is that they are expressions of the idea that the derivative is part of a functor.", "A functor is an operation on spaces and functions between them.", "It associates to each space a new space and to each function between two spaces a new function between the corresponding new spaces.", "In each of the above cases, the functor sends each space to its tangent bundle and it sends each function to its derivative.", "For example, in the manifold case, the derivative sends a ''C''''r''-manifold to a ''C''''r''−1-manifold (its tangent bundle) and a ''C''''r''-function to its total derivative.", "There is one requirement for this to be a functor, namely that the derivative of a composite must be the composite of the derivatives.", "This is exactly the formula .There are also chain rules in stochastic calculus.", "One of these, Itō's lemma, expresses the composite of an Itō process (or more generally a semimartingale) ''dX''''t'' with a twice-differentiable function ''f''.", "In Itō's lemma, the derivative of the composite function depends not only on ''dX''''t'' and the derivative of ''f'' but also on the second derivative of ''f''.", "The dependence on the second derivative is a consequence of the non-zero quadratic variation of the stochastic process, which broadly speaking means that the process can move up and down in a very rough way.", "This variant of the chain rule is not an example of a functor because the two functions being composed are of different types." ], [ "See also", "* − a computational method that makes heavy use of the chain rule to compute exact numerical derivatives.", "* * * * * *" ], [ "References" ], [ "External links", "* *" ] ]
wikipedia
[ [ "P versus NP problem" ], [ "Introduction", "The '''P versus NP problem''' is a major unsolved problem in theoretical computer science.", "In informal terms, it asks whether every problem whose solution can be quickly verified can also be quickly solved.The informal term ''quickly'', used above, means the existence of an algorithm solving the task that runs in polynomial time, such that the time to complete the task varies as a polynomial function on the size of the input to the algorithm (as opposed to, say, exponential time).", "The general class of questions for which some algorithm can provide an answer in polynomial time is \"'''P'''\" or \"'''class P'''\".", "For some questions, there is no known way to find an answer quickly, but if one is provided with information showing what the answer is, it is possible to verify the answer quickly.", "The class of questions for which an answer can be ''verified'' in polynomial time is '''NP''', which stands for \"nondeterministic polynomial time\".An answer to the P versus NP question would determine whether problems that can be verified in polynomial time can also be solved in polynomial time.", "If it turns out that P ≠ NP, which is widely believed, it would mean that there are problems in NP that are harder to compute than to verify: they could not be solved in polynomial time, but the answer could be verified in polynomial time.The problem has been called the most important open problem in computer science.", "Aside from being an important problem in computational theory, a proof either way would have profound implications for mathematics, cryptography, algorithm research, artificial intelligence, game theory, multimedia processing, philosophy, economics and many other fields.It is one of the seven Millennium Prize Problems selected by the Clay Mathematics Institute, each of which carries a US$1,000,000 prize for the first correct solution." ], [ "Example", "Consider Sudoku, a game where the player is given a partially filled-in grid of numbers and attempts to complete the grid following certain rules.", "Given an incomplete Sudoku grid, of any size, is there at least one legal solution?", "Any proposed solution is easily verified, and the time to check a solution grows slowly (polynomially) as the grid gets bigger.", "However, all known algorithms for finding solutions take, for difficult examples, time that grows exponentially as the grid gets bigger.", "So, Sudoku is in NP (quickly checkable) but does not seem to be in P (quickly solvable).", "Thousands of other problems seem similar, in that they are fast to check but slow to solve.", "Researchers have shown that many of the problems in NP have the extra property that a fast solution to any one of them could be used to build a quick solution to any other problem in NP, a property called NP-completeness.", "Decades of searching have not yielded a fast solution to any of these problems, so most scientists suspect that none of these problems can be solved quickly.", "This, however, has never been proven." ], [ "History", "The precise statement of the P versus NP problem was introduced in 1971 by Stephen Cook in his seminal paper \"The complexity of theorem proving procedures\" (and independently by Leonid Levin in 1973).Although the P versus NP problem was formally defined in 1971, there were previous inklings of the problems involved, the difficulty of proof, and the potential consequences.", "In 1955, mathematician John Nash wrote a letter to the NSA, in which he speculated that cracking a sufficiently complex code would require time exponential in the length of the key.", "If proved (and Nash was suitably skeptical), this would imply what is now called P ≠ NP, since a proposed key can easily be verified in polynomial time.", "Another mention of the underlying problem occurred in a 1956 letter written by Kurt Gödel to John von Neumann.", "Gödel asked whether theorem-proving (now known to be co-NP-complete) could be solved in quadratic or linear time, and pointed out one of the most important consequences—that if so, then the discovery of mathematical proofs could be automated." ], [ "Context", "The relation between the complexity classes P and NP is studied in computational complexity theory, the part of the theory of computation dealing with the resources required during computation to solve a given problem.", "The most common resources are time (how many steps it takes to solve a problem) and space (how much memory it takes to solve a problem).In such analysis, a model of the computer for which time must be analyzed is required.", "Typically such models assume that the computer is ''deterministic'' (given the computer's present state and any inputs, there is only one possible action that the computer might take) and ''sequential'' (it performs actions one after the other).In this theory, the class P consists of all those ''decision problems'' (defined below) that can be solved on a deterministic sequential machine in an amount of time that is polynomial in the size of the input; the class NP consists of all those decision problems whose positive solutions can be verified in polynomial time given the right information, or equivalently, whose solution can be found in polynomial time on a non-deterministic machine.", "Clearly, P ⊆ NP.", "Arguably, the biggest open question in theoretical computer science concerns the relationship between those two classes::Is P equal to NP?Since 2002, William Gasarch has conducted three polls of researchers concerning this and related questions.", "Confidence that P ≠ NP has been increasing – in 2019, 88% believed P ≠ NP, as opposed to 83% in 2012 and 61% in 2002.When restricted to experts, the 2019 answers became 99% believed P ≠ NP.", "These polls do not imply anything about whether P = NP is true, as stated by Gasarch himself: \"This does not bring us any closer to solving P=?NP or to knowing when it will be solved, but it attempts to be an objective report on the subjective opinion of this era.\"" ], [ "NP-completeness", "Euler diagram for P, NP, NP-complete, and NP-hard set of problems (excluding the empty language and its complement, which belong to P but are not NP-complete)To attack the P = NP question, the concept of NP-completeness is very useful.", "NP-complete problems are a set of problems to each of which any other NP problem can be reduced in polynomial time and whose solution may still be verified in polynomial time.", "That is, any NP problem can be transformed into any of the NP-complete problems.", "Informally, an NP-complete problem is an NP problem that is at least as \"tough\" as any other problem in NP.NP-hard problems are those at least as hard as NP problems; i.e., all NP problems can be reduced (in polynomial time) to them.", "NP-hard problems need not be in NP; i.e., they need not have solutions verifiable in polynomial time.For instance, the Boolean satisfiability problem is NP-complete by the Cook–Levin theorem, so ''any'' instance of ''any'' problem in NP can be transformed mechanically into an instance of the Boolean satisfiability problem in polynomial time.", "The Boolean satisfiability problem is one of many such NP-complete problems.", "If any NP-complete problem is in P, then it would follow that P = NP.", "However, many important problems have been shown to be NP-complete, and no fast algorithm for any of them is known.Based on the definition alone it is not obvious that NP-complete problems exist; however, a trivial and contrived NP-complete problem can be formulated as follows: given a description of a Turing machine ''M'' guaranteed to halt in polynomial time, does there exist a polynomial-size input that ''M'' will accept?", "It is in NP because (given an input) it is simple to check whether ''M'' accepts the input by simulating ''M''; it is NP-complete because the verifier for any particular instance of a problem in NP can be encoded as a polynomial-time machine ''M'' that takes the solution to be verified as input.", "Then the question of whether the instance is a yes or no instance is determined by whether a valid input exists.The first natural problem proven to be NP-complete was the Boolean satisfiability problem, also known as SAT.", "As noted above, this is the Cook–Levin theorem; its proof that satisfiability is NP-complete contains technical details about Turing machines as they relate to the definition of NP.", "However, after this problem was proved to be NP-complete, proof by reduction provided a simpler way to show that many other problems are also NP-complete, including the game Sudoku discussed earlier.", "In this case, the proof shows that a solution of Sudoku in polynomial time could also be used to complete Latin squares in polynomial time.", "This in turn gives a solution to the problem of partitioning tri-partite graphs into triangles, which could then be used to find solutions for the special case of SAT known as 3-SAT, which then provides a solution for general Boolean satisfiability.", "So a polynomial-time solution to Sudoku leads, by a series of mechanical transformations, to a polynomial time solution of satisfiability, which in turn can be used to solve any other NP-problem in polynomial time.", "Using transformations like this, a vast class of seemingly unrelated problems are all reducible to one another, and are in a sense \"the same problem\"." ], [ "Harder problems", "Although it is unknown whether P = NP, problems outside of P are known.", "Just as the class P is defined in terms of polynomial running time, the class EXPTIME is the set of all decision problems that have ''exponential'' running time.", "In other words, any problem in EXPTIME is solvable by a deterministic Turing machine in O(2''p''(''n'')) time, where ''p''(''n'') is a polynomial function of ''n''.", "A decision problem is EXPTIME-complete if it is in EXPTIME, and every problem in EXPTIME has a polynomial-time many-one reduction to it.", "A number of problems are known to be EXPTIME-complete.", "Because it can be shown that P ≠ EXPTIME, these problems are outside P, and so require more than polynomial time.", "In fact, by the time hierarchy theorem, they cannot be solved in significantly less than exponential time.", "Examples include finding a perfect strategy for chess positions on an ''N'' × ''N'' board and similar problems for other board games.The problem of deciding the truth of a statement in Presburger arithmetic requires even more time.", "Fischer and Rabin proved in 1974 that every algorithm that decides the truth of Presburger statements of length ''n'' has a runtime of at least for some constant ''c''.", "Hence, the problem is known to need more than exponential run time.", "Even more difficult are the undecidable problems, such as the halting problem.", "They cannot be completely solved by any algorithm, in the sense that for any particular algorithm there is at least one input for which that algorithm will not produce the right answer; it will either produce the wrong answer, finish without giving a conclusive answer, or otherwise run forever without producing any answer at all.It is also possible to consider questions other than decision problems.", "One such class, consisting of counting problems, is called #P: whereas an NP problem asks \"Are there any solutions?", "\", the corresponding #P problem asks \"How many solutions are there?\".", "Clearly, a #P problem must be at least as hard as the corresponding NP problem, since a count of solutions immediately tells if at least one solution exists, if the count is greater than zero.", "Surprisingly, some #P problems that are believed to be difficult correspond to easy (for example linear-time) P problems.", "For these problems, it is very easy to tell whether solutions exist, but thought to be very hard to tell how many.", "Many of these problems are #P-complete, and hence among the hardest problems in #P, since a polynomial time solution to any of them would allow a polynomial time solution to all other #P problems." ], [ "Problems in NP not known to be in P or NP-complete", "In 1975, Richard E. Ladner showed that if P ≠ NP, then there exist problems in NP that are neither in P nor NP-complete.", "Such problems are called NP-intermediate problems.", "The graph isomorphism problem, the discrete logarithm problem, and the integer factorization problem are examples of problems believed to be NP-intermediate.", "They are some of the very few NP problems not known to be in P or to be NP-complete.The graph isomorphism problem is the computational problem of determining whether two finite graphs are isomorphic.", "An important unsolved problem in complexity theory is whether the graph isomorphism problem is in P, NP-complete, or NP-intermediate.", "The answer is not known, but it is believed that the problem is at least not NP-complete.", "If graph isomorphism is NP-complete, the polynomial time hierarchy collapses to its second level.", "Since it is widely believed that the polynomial hierarchy does not collapse to any finite level, it is believed that graph isomorphism is not NP-complete.", "The best algorithm for this problem, due to László Babai, runs in quasi-polynomial time.The integer factorization problem is the computational problem of determining the prime factorization of a given integer.", "Phrased as a decision problem, it is the problem of deciding whether the input has a factor less than ''k''.", "No efficient integer factorization algorithm is known, and this fact forms the basis of several modern cryptographic systems, such as the RSA algorithm.", "The integer factorization problem is in NP and in co-NP (and even in UP and co-UP).", "If the problem is NP-complete, the polynomial time hierarchy will collapse to its first level (i.e., NP = co-NP).", "The most efficient known algorithm for integer factorization is the general number field sieve, which takes expected time:to factor an ''n''-bit integer.", "The best known quantum algorithm for this problem, Shor's algorithm, runs in polynomial time, although this does not indicate where the problem lies with respect to non-quantum complexity classes." ], [ "Does P mean \"easy\"?", "The graph shows the running time vs. problem size for a knapsack problem of a state-of-the-art, specialized algorithm.", "The quadratic fit suggests that the algorithmic complexity of the problem is O((log(''n''))2).All of the above discussion has assumed that P means \"easy\" and \"not in P\" means \"difficult\", an assumption known as ''Cobham's thesis''.", "It is a common and reasonably accurate assumption in complexity theory; however, it has some caveats.First, it is not always true in practice.", "A theoretical polynomial algorithm may have extremely large constant factors or exponents, thus rendering it impractical.", "For example, the problem of deciding whether a graph ''G'' contains ''H'' as a minor, where ''H'' is fixed, can be solved in a running time of ''O''(''n''2), where ''n'' is the number of vertices in ''G''.", "However, the big O notation hides a constant that depends superexponentially on ''H''.", "The constant is greater than (using Knuth's up-arrow notation), and where ''h'' is the number of vertices in ''H''.On the other hand, even if a problem is shown to be NP-complete, and even if P ≠ NP, there may still be effective approaches to tackling the problem in practice.", "There are algorithms for many NP-complete problems, such as the knapsack problem, the traveling salesman problem, and the Boolean satisfiability problem, that can solve to optimality many real-world instances in reasonable time.", "The empirical average-case complexity (time vs. problem size) of such algorithms can be surprisingly low.", "An example is the simplex algorithm in linear programming, which works surprisingly well in practice; despite having exponential worst-case time complexity, it runs on par with the best known polynomial-time algorithms.Finally, there are types of computations which do not conform to the Turing machine model on which P and NP are defined, such as quantum computation and randomized algorithms." ], [ "Reasons to believe P ≠ NP or P = NP", "Cook provides a restatement of the problem in ''The P Versus NP Problem'' as \"Does P = NP?\"", "According to polls, most computer scientists believe that P ≠ NP.", "A key reason for this belief is that after decades of studying these problems no one has been able to find a polynomial-time algorithm for any of more than 3000 important known NP-complete problems (see List of NP-complete problems).", "These algorithms were sought long before the concept of NP-completeness was even defined (Karp's 21 NP-complete problems, among the first found, were all well-known existing problems at the time they were shown to be NP-complete).", "Furthermore, the result P = NP would imply many other startling results that are currently believed to be false, such as NP = co-NP and P = PH.It is also intuitively argued that the existence of problems that are hard to solve but for which the solutions are easy to verify matches real-world experience.On the other hand, some researchers believe that there is overconfidence in believing P ≠ NP and that researchers should explore proofs of P = NP as well.", "For example, in 2002 these statements were made:===DLIN vs NLIN===When one substitutes \"linear time on a multitape Turing machine\" for \"polynomial time\" in the definitions of P and NP, one obtains the classes DLIN and NLIN.It is known that DLIN≠NLIN." ], [ "Consequences of solution", "One of the reasons the problem attracts so much attention is the consequences of the possible answers.", "Either direction of resolution would advance theory enormously, and perhaps have huge practical consequences as well.===P = NP===A proof that P = NP could have stunning practical consequences if the proof leads to efficient methods for solving some of the important problems in NP.", "The potential consequences, both positive and negative, arise since various NP-complete problems are fundamental in many fields.It is also very possible that a proof would ''not'' lead to practical algorithms for NP-complete problems.", "The formulation of the problem does not require that the bounding polynomial be small or even specifically known.", "A non-constructive proof might show a solution exists without specifying either an algorithm to obtain it or a specific bound.", "Even if the proof is constructive, showing an explicit bounding polynomial and algorithmic details, if the polynomial is not very low-order the algorithm might not be sufficiently efficient in practice.", "In this case the initial proof would be mainly of interest to theoreticians, but the knowledge that polynomial time solutions are possible would surely spur research into better (and possibly practical) methods to achieve them.An example of a field that could be upended by a solution showing P = NP is cryptography, which relies on certain problems being difficult.", "A constructive and efficient solution to an NP-complete problem such as 3-SAT would break most existing cryptosystems including:* Existing implementations of public-key cryptography, a foundation for many modern security applications such as secure financial transactions over the Internet.", "* Symmetric ciphers such as AES or 3DES, used for the encryption of communications data.", "* Cryptographic hashing, which underlies blockchain cryptocurrencies such as Bitcoin, and is used to authenticate software updates.", "For these applications, the problem of finding a pre-image that hashes to a given value must be difficult in order to be useful, and ideally should require exponential time.", "However, if P = NP, then finding a pre-image ''M'' can be done in polynomial time, through reduction to SAT.These would need to be modified or replaced by information-theoretically secure solutions not inherently based on P–NP inequivalence.On the other hand, there are enormous positive consequences that would follow from rendering tractable many currently mathematically intractable problems.", "For instance, many problems in operations research are NP-complete, such as some types of integer programming and the travelling salesman problem.", "Efficient solutions to these problems would have enormous implications for logistics.", "Many other important problems, such as some problems in protein structure prediction, are also NP-complete; if these problems were efficiently solvable, it could spur considerable advances in life sciences and biotechnology.But such changes may pale in significance compared to the revolution an efficient method for solving NP-complete problems would cause in mathematics itself.", "Gödel, in his early thoughts on computational complexity, noted that a mechanical method that could solve any problem would revolutionize mathematics:Similarly, Stephen Cook (assuming not only a proof, but a practically efficient algorithm) says:Research mathematicians spend their careers trying to prove theorems, and some proofs have taken decades or even centuries to find after problems have been stated—for instance, Fermat's Last Theorem took over three centuries to prove.", "A method that is guaranteed to find proofs to theorems, should one exist of a \"reasonable\" size, would essentially end this struggle.Donald Knuth has stated that he has come to believe that P = NP, but is reserved about the impact of a possible proof:Diagram of complexity classes provided that P ≠ NP.", "The existence of problems within NP but outside both P and NP-complete, under that assumption, was established by Ladner's theorem.===P ≠ NP===A proof showing that P ≠ NP would lack the practical computational benefits of a proof that P = NP, but would nevertheless represent a very significant advance in computational complexity theory and provide guidance for future research.", "It would allow one to show in a formal way that many common problems cannot be solved efficiently, so that the attention of researchers can be focused on partial solutions or solutions to other problems.", "Due to widespread belief in P ≠ NP, much of this focusing of research has already taken place.Also, P ≠ NP still leaves open the average-case complexity of hard problems in NP.", "For example, it is possible that SAT requires exponential time in the worst case, but that almost all randomly selected instances of it are efficiently solvable.", "Russell Impagliazzo has described five hypothetical \"worlds\" that could result from different possible resolutions to the average-case complexity question.", "These range from \"Algorithmica\", where P = NP and problems like SAT can be solved efficiently in all instances, to \"Cryptomania\", where P ≠ NP and generating hard instances of problems outside P is easy, with three intermediate possibilities reflecting different possible distributions of difficulty over instances of NP-hard problems.", "The \"world\" where P ≠ NP but all problems in NP are tractable in the average case is called \"Heuristica\" in the paper.", "A Princeton University workshop in 2009 studied the status of the five worlds." ], [ "Results about difficulty of proof", "Although the P = NP problem itself remains open despite a million-dollar prize and a huge amount of dedicated research, efforts to solve the problem have led to several new techniques.", "In particular, some of the most fruitful research related to the P = NP problem has been in showing that existing proof techniques are not powerful enough to answer the question, thus suggesting that novel technical approaches are required.As additional evidence for the difficulty of the problem, essentially all known proof techniques in computational complexity theory fall into one of the following classifications, each of which is known to be insufficient to prove that P ≠ NP:ClassificationDefinitionRelativizing proofsImagine a world where every algorithm is allowed to make queries to some fixed subroutine called an ''oracle'' (a black box which can answer a fixed set of questions in constant time, such as a black box that solves any given traveling salesman problem in 1 step), and the running time of the oracle is not counted against the running time of the algorithm.", "Most proofs (especially classical ones) apply uniformly in a world with oracles regardless of what the oracle does.", "These proofs are called ''relativizing''.", "In 1975, Baker, Gill, and Solovay showed that P = NP with respect to some oracles, while P ≠ NP for other oracles.", "Since relativizing proofs can only prove statements that are uniformly true with respect to all possible oracles, this showed that relativizing techniques cannot resolve P = NP.Natural proofsIn 1993, Alexander Razborov and Steven Rudich defined a general class of proof techniques for circuit complexity lower bounds, called ''natural proofs''.", "At the time, all previously known circuit lower bounds were natural, and circuit complexity was considered a very promising approach for resolving P = NP.", "However, Razborov and Rudich showed that if one-way functions exist, then no natural proof method can distinguish between P and NP.", "Although one-way functions have never been formally proven to exist, most mathematicians believe that they do, and a proof of their existence would be a much stronger statement than P ≠ NP.", "Thus it is unlikely that natural proofs alone can resolve P = NP.Algebrizing proofsAfter the Baker–Gill–Solovay result, new non-relativizing proof techniques were successfully used to prove that IP = PSPACE.", "However, in 2008, Scott Aaronson and Avi Wigderson showed that the main technical tool used in the IP = PSPACE proof, known as ''arithmetization'', was also insufficient to resolve P = NP.", "Arithmetization converts the operations of an algorithm to algebraic and basic arithmetic symbols and then uses those to analyze the workings.", "In the IP = PSPACE proof, they convert the black box and the Boolean circuits to an algebraic problem.", "As mentioned previously, it has proven that this method is not viable to solve P = NP and other time complexity problems.These barriers are another reason why NP-complete problems are useful: if a polynomial-time algorithm can be demonstrated for an NP-complete problem, this would solve the P = NP problem in a way not excluded by the above results.These barriers have also led some computer scientists to suggest that the P versus NP problem may be independent of standard axiom systems like ZFC (cannot be proved or disproved within them).", "The interpretation of an independence result could be that either no polynomial-time algorithm exists for any NP-complete problem, and such a proof cannot be constructed in (e.g.)", "ZFC, or that polynomial-time algorithms for NP-complete problems may exist, but it is impossible to prove in ZFC that such algorithms are correct.", "However, if it can be shown, using techniques of the sort that are currently known to be applicable, that the problem cannot be decided even with much weaker assumptions extending the Peano axioms (PA) for integer arithmetic, then there would necessarily exist nearly polynomial-time algorithms for every problem in NP.", "Therefore, if one believes (as most complexity theorists do) that not all problems in NP have efficient algorithms, it would follow that proofs of independence using those techniques cannot be possible.", "Additionally, this result implies that proving independence from PA or ZFC using currently known techniques is no easier than proving the existence of efficient algorithms for all problems in NP." ], [ "Logical characterizations", "The P = NP problem can be restated in terms of expressible certain classes of logical statements, as a result of work in descriptive complexity.Consider all languages of finite structures with a fixed signature including a linear order relation.", "Then, all such languages in P can be expressed in first-order logic with the addition of a suitable least fixed-point combinator.", "Effectively, this, in combination with the order, allows the definition of recursive functions.", "As long as the signature contains at least one predicate or function in addition to the distinguished order relation, so that the amount of space taken to store such finite structures is actually polynomial in the number of elements in the structure, this precisely characterizes P.Similarly, NP is the set of languages expressible in existential second-order logic—that is, second-order logic restricted to exclude universal quantification over relations, functions, and subsets.", "The languages in the polynomial hierarchy, PH, correspond to all of second-order logic.", "Thus, the question \"is P a proper subset of NP\" can be reformulated as \"is existential second-order logic able to describe languages (of finite linearly ordered structures with nontrivial signature) that first-order logic with least fixed point cannot?\".", "The word \"existential\" can even be dropped from the previous characterization, since P = NP if and only if P = PH (as the former would establish that NP = co-NP, which in turn implies that NP = PH)." ], [ "Polynomial-time algorithms", "No algorithm for any NP-complete problem is known to run in polynomial time.", "However, there are algorithms known for NP-complete problems with the property that if P = NP, then the algorithm runs in polynomial time on accepting instances (although with enormous constants, making the algorithm impractical).", "However, these algorithms do not qualify as polynomial time because their running time on rejecting instances are not polynomial.", "The following algorithm, due to Levin (without any citation), is such an example below.", "It correctly accepts the NP-complete language SUBSET-SUM.", "It runs in polynomial time on inputs that are in SUBSET-SUM if and only if P = NP: ''// Algorithm that accepts the NP-complete language SUBSET-SUM.''", "''//'' ''// this is a polynomial-time algorithm if and only if P = NP.''", "''//'' ''// \"Polynomial-time\" means it returns \"yes\" in polynomial time when'' ''// the answer should be \"yes\", and runs forever when it is \"no\".''", "''//'' ''// Input: S = a finite set of integers'' ''// Output: \"yes\" if any subset of S adds up to 0.''", "''// Runs forever with no output otherwise.''", "''// Note: \"Program number M\" is the program obtained by'' ''// writing the integer M in binary, then'' ''// considering that string of bits to be a'' ''// program.", "Every possible program can be'' ''// generated this way, though most do nothing'' ''// because of syntax errors.''", "FOR K = 1...∞ FOR M = 1...K Run program number M for K steps with input S IF the program outputs a list of distinct integers AND the integers are all in S AND the integers sum to 0 THEN OUTPUT \"yes\" and HALTIf, and only if, P = NP, then this is a polynomial-time algorithm accepting an NP-complete language.", "\"Accepting\" means it gives \"yes\" answers in polynomial time, but is allowed to run forever when the answer is \"no\" (also known as a ''semi-algorithm'').This algorithm is enormously impractical, even if P = NP.", "If the shortest program that can solve SUBSET-SUM in polynomial time is ''b'' bits long, the above algorithm will try at least other programs first." ], [ "Formal definitions", "===P and NP===Conceptually speaking, a ''decision problem'' is a problem that takes as input some string ''w'' over an alphabet Σ, and outputs \"yes\" or \"no\".", "If there is an algorithm (say a Turing machine, or a computer program with unbounded memory) that can produce the correct answer for any input string of length ''n'' in at most ''cnk'' steps, where ''k'' and ''c'' are constants independent of the input string, then we say that the problem can be solved in ''polynomial time'' and we place it in the class P. Formally, P is defined as the set of all languages that can be decided by a deterministic polynomial-time Turing machine.", "That is,:where:and a deterministic polynomial-time Turing machine is a deterministic Turing machine ''M'' that satisfies the following two conditions:# ''M'' halts on all inputs ''w'' and# there exists such that , where ''O'' refers to the big O notation and::::NP can be defined similarly using nondeterministic Turing machines (the traditional way).", "However, a modern approach to define NP is to use the concept of ''certificate'' and ''verifier''.", "Formally, NP is defined as the set of languages over a finite alphabet that have a verifier that runs in polynomial time, where the notion of \"verifier\" is defined as follows.Let ''L'' be a language over a finite alphabet, Σ.", "''L'' ∈ NP if, and only if, there exists a binary relation and a positive integer ''k'' such that the following two conditions are satisfied:# For all , such that (''x'', ''y'') ∈ ''R'' and ; and# the language over is decidable by a deterministic Turing machine in polynomial time.A Turing machine that decides ''LR'' is called a ''verifier'' for ''L'' and a ''y'' such that (''x'', ''y'') ∈ ''R'' is called a ''certificate of membership'' of ''x'' in ''L''.In general, a verifier does not have to be polynomial-time.", "However, for ''L'' to be in NP, there must be a verifier that runs in polynomial time.====Example====Let::Clearly, the question of whether a given ''x'' is a composite is equivalent to the question of whether ''x'' is a member of COMPOSITE.", "It can be shown that COMPOSITE ∈ NP by verifying that it satisfies the above definition (if we identify natural numbers with their binary representations).COMPOSITE also happens to be in P, a fact demonstrated by the invention of the AKS primality test.===NP-completeness===There are many equivalent ways of describing NP-completeness.Let ''L'' be a language over a finite alphabet Σ.", "''L'' is NP-complete if, and only if, the following two conditions are satisfied:# ''L'' ∈ NP; and# any ''L''' in NP is polynomial-time-reducible to ''L'' (written as ), where if, and only if, the following two conditions are satisfied:## There exists ''f'' : Σ* → Σ* such that for all ''w'' in Σ* we have: ; and## there exists a polynomial-time Turing machine that halts with ''f''(''w'') on its tape on any input ''w''.Alternatively, if ''L'' ∈ NP, and there is another NP-complete problem that can be polynomial-time reduced to ''L'', then ''L'' is NP-complete.", "This is a common way of proving some new problem is NP-complete." ], [ "Claimed solutions", "While the P versus NP problem is generally considered unsolved, many amateur and some professional researchers have claimed solutions.", "Gerhard J. Woeginger compiled a list of 62 purported proofs of P = NP from 1986 to 2016, of which 50 were proofs of P ≠ NP, 2 were proofs the problem is unprovable, and one was a proof that it is undecidable.", "Some attempts at resolving P versus NP have received brief media attention, though these attempts have since been refuted." ], [ "Popular culture", "The film ''Travelling Salesman'', by director Timothy Lanzone, is the story of four mathematicians hired by the US government to solve the P versus NP problem.In the sixth episode of ''The Simpsons'' seventh season \"Treehouse of Horror VI\", the equation P = NP is seen shortly after Homer accidentally stumbles into the \"third dimension\".In the second episode of season 2 of ''Elementary'', \"Solve for X\" revolves around Sherlock and Watson investigating the murders of mathematicians who were attempting to solve P versus NP." ], [ "See also", "* Game complexity* List of unsolved problems in mathematics* Unique games conjecture* Unsolved problems in computer science" ], [ "Notes" ], [ "References" ], [ "Sources", "** *" ], [ "Further reading", "* * * Online drafts* *" ], [ "External links", "* * Aviad Rubinstein's ''Hardness of Approximation Between P and NP'', winner of the ACM's 2017 Doctoral Dissertation Award.", "*" ] ]
wikipedia
[ [ "Charles Sanders Peirce" ], [ "Introduction", "'''Charles Sanders Peirce''' ( ; September 10, 1839 – April 19, 1914) was an American scientist, mathematician, logician, and philosopher who is sometimes known as \"the father of pragmatism\".", "According to philosopher Paul Weiss, Peirce was \"the most original and versatile of America's philosophers and America's greatest logician\".", "Bertrand Russell wrote \"he was one of the most original minds of the later nineteenth century and certainly the greatest American thinker ever\".", "Educated as a chemist and employed as a scientist for thirty years, Peirce meanwhile made major contributions to logic, such as theories of relations and quantification.", "C. I. Lewis wrote, \"The contributions of C.S.", "Peirce to symbolic logic are more numerous and varied than those of any other writer—at least in the nineteenth century.\"", "For Peirce, logic also encompassed much of what is now called epistemology and the philosophy of science.", "He saw logic as the formal branch of semiotics or study of signs, of which he is a founder, which foreshadowed the debate among logical positivists and proponents of philosophy of language that dominated 20th-century Western philosophy.", "Peirce's study of signs also included a tripartite theory of predication.", "Additionally, he defined the concept of abductive reasoning, as well as rigorously formulating mathematical induction and deductive reasoning.", "He was one of the founders of statistics.", "As early as 1886, he saw that logical operations could be carried out by electrical switching circuits.", "The same idea was used decades later to produce digital computers.For metaphysics, Peirce was an \"objective idealist\" in the tradition of German philosopher Immanuel Kant as well as a scholastic realist about universals.", "He also held a commitment to the ideas of continuity and chance as real features of the universe, views he labeled synechism and tychism respectively.", "Peirce believed an epistemic fallibilism and anti-skepticism went along with these views." ], [ "Biography", "=== Early life ===Peirce's birthplace.", "Now part of Lesley University's Graduate School of Arts and Social Sciences.Peirce was born at 3 Phillips Place in Cambridge, Massachusetts.", "He was the son of Sarah Hunt Mills and Benjamin Peirce, himself a professor of mathematics and astronomy at Harvard University.", "At age 12, Charles read his older brother's copy of Richard Whately's ''Elements of Logic'', then the leading English-language text on the subject.", "So began his lifelong fascination with logic and reasoning.", "He suffered from his late teens onward from a nervous condition then known as \"facial neuralgia\", which would today be diagnosed as trigeminal neuralgia.", "His biographer, Joseph Brent, says that when in the throes of its pain \"he was, at first, almost stupefied, and then aloof, cold, depressed, extremely suspicious, impatient of the slightest crossing, and subject to violent outbursts of temper\".", "Its consequences may have led to the social isolation of his later life.=== Education ===Peirce went on to earn a Bachelor of Arts degree and a Master of Arts degree (1862) from Harvard.", "In 1863 the Lawrence Scientific School awarded him a Bachelor of Science degree, Harvard's first ''summa cum laude'' chemistry degree.", "His academic record was otherwise undistinguished.", "At Harvard, he began lifelong friendships with Francis Ellingwood Abbot, Chauncey Wright, and William James.", "One of his Harvard instructors, Charles William Eliot, formed an unfavorable opinion of Peirce.", "This proved fateful, because Eliot, while President of Harvard (1869–1909—a period encompassing nearly all of Peirce's working life), repeatedly vetoed Peirce's employment at the university.=== United States Coast Survey ===Peirce in 1859.Between 1859 and 1891, Peirce was intermittently employed in various scientific capacities by the United States Coast Survey, which in 1878 was renamed the United States Coast and Geodetic Survey, where he enjoyed his highly influential father's protection until the latter's death in 1880.At the Survey, he worked mainly in geodesy and gravimetry, refining the use of pendulums to determine small local variations in the Earth's gravity.==== American Civil War ====This employment exempted Peirce from having to take part in the American Civil War; it would have been very awkward for him to do so, as the Boston Brahmin Peirces sympathized with the Confederacy.", "No members of the Peirce family volunteered or enlisted.", "Peirce grew up in a home where white supremacy was taken for granted, and slavery was considered natural.", "Peirce's father had described himself as a secessionist until the outbreak of the war, after which he became a Union partisan, providing donations to the Sanitary Commission, the leading Northern war charity.", "Peirce liked to use the following syllogism to illustrate the unreliability of traditional forms of logic (for the first premise arguably assumes the conclusion):All Men are equal in their political rights.Negroes are Men.Therefore, negroes are equal in political rights to whites.==== Travels to Europe ====He was elected a resident fellow of the American Academy of Arts and Sciences in January 1867.The Survey sent him to Europe five times, first in 1871 as part of a group sent to observe a solar eclipse.", "There, he sought out Augustus De Morgan, William Stanley Jevons, and William Kingdon Clifford, British mathematicians and logicians whose turn of mind resembled his own.", "==== Harvard observatory ====From 1869 to 1872, he was employed as an assistant in Harvard's astronomical observatory, doing important work on determining the brightness of stars and the shape of the Milky Way.", "In 1872 he founded the Metaphysical Club, a conversational philosophical club that Peirce, the future Supreme Court Justice Oliver Wendell Holmes Jr., the philosopher and psychologist William James, amongst others, formed in January 1872 in Cambridge, Massachusetts, and dissolved in December 1872.Other members of the club included Chauncey Wright, John Fiske, Francis Ellingwood Abbot, Nicholas St. John Green, and Joseph Bangs Warner.", "The discussions eventually birthed Peirce's notion of pragmatism.==== National Academy of Sciences ====Quincuncial Projection\", 1879.Peirce’s projection of a sphere onto a square keeps angles true except at four isolated points on the equator, and has less scale variation than the Mercator projection.", "It can be tessellated; that is, multiple copies can be joined together continuously edge-to-edge.On April 20, 1877, he was elected a member of the National Academy of Sciences.", "Also in 1877, he proposed measuring the meter as so many wavelengths of light of a certain frequency, the kind of definition employed from 1960 to 1983.In 1879 Peirce developed Peirce quincuncial projection, having been inspired by H. A. Schwarz's 1869 conformal transformation of a circle onto a polygon of ''n'' sides (known as the Schwarz–Christoffel mapping).", "==== 1880 to 1891 ====During the 1880s, Peirce's indifference to bureaucratic detail waxed while his Survey work's quality and timeliness waned.", "Peirce took years to write reports that he should have completed in months.", "Meanwhile, he wrote entries, ultimately thousands, during 1883–1909 on philosophy, logic, science, and other subjects for the encyclopedic ''Century Dictionary''.", "In 1885, an investigation by the Allison Commission exonerated Peirce, but led to the dismissal of Superintendent Julius Hilgard and several other Coast Survey employees for misuse of public funds.", "In 1891, Peirce resigned from the Coast Survey at Superintendent Thomas Corwin Mendenhall's request.=== Johns Hopkins University ===In 1879, Peirce was appointed lecturer in logic at Johns Hopkins University, which had strong departments in areas that interested him, such as philosophy (Royce and Dewey completed their PhDs at Hopkins), psychology (taught by G. Stanley Hall and studied by Joseph Jastrow, who coauthored a landmark empirical study with Peirce), and mathematics (taught by J. J. Sylvester, who came to admire Peirce's work on mathematics and logic).", "His ''Studies in Logic by Members of the Johns Hopkins University'' (1883) contained works by himself and Allan Marquand, Christine Ladd, Benjamin Ives Gilman, and Oscar Howard Mitchell, several of whom were his graduate students.", "Peirce's nontenured position at Hopkins was the only academic appointment he ever held.Brent documents something Peirce never suspected, namely that his efforts to obtain academic employment, grants, and scientific respectability were repeatedly frustrated by the covert opposition of a major Canadian-American scientist of the day, Simon Newcomb.", "Newcomb had been a favourite student of Peirce's father; although \"no doubt quite bright\", \"like Salieri in Peter Shaffer’s Amadeus he also had just enough talent to recognize he was not a genius and just enough pettiness to resent someone who was\".", "Additionally \"an intensely devout and literal-minded Christian of rigid moral standards\", he was appalled by what he considered Peirce's personal shortcomings.", "Peirce's efforts may also have been hampered by what Brent characterizes as \"his difficult personality\".", "In contrast, Keith Devlin believes that Peirce's work was too far ahead of his time to be appreciated by the academic establishment of the day and that this played a large role in his inability to obtain a tenured position.=== Personal life ===Juliette and Charles by a well at their home Arisbe in 1907Peirce's personal life undoubtedly worked against his professional success.", "After his first wife, Harriet Melusina Fay (\"Zina\"), left him in 1875, Peirce, while still legally married, became involved with Juliette, whose last name, given variously as Froissy and Pourtalai, and nationality (she spoke French) remains uncertain.", "When his divorce from Zina became final in 1883, he married Juliette.", "That year, Newcomb pointed out to a Johns Hopkins trustee that Peirce, while a Hopkins employee, had lived and traveled with a woman to whom he was not married; the ensuing scandal led to his dismissal in January 1884.Over the years Peirce sought academic employment at various universities without success.", "He had no children by either marriage.=== Later life and poverty ===Arisbe in 2011Charles and Juliette Peirce's graveIn 1887, Peirce spent part of his inheritance from his parents to buy of rural land near Milford, Pennsylvania, which never yielded an economic return.", "There he had an 1854 farmhouse remodeled to his design.", "The Peirces named the property \"Arisbe\".", "There they lived with few interruptions for the rest of their lives, Charles writing prolifically, with much of his work remaining unpublished to this day (see Works).", "Living beyond their means soon led to grave financial and legal difficulties.", "Charles spent much of his last two decades unable to afford heat in winter and subsisting on old bread donated by the local baker.", "Unable to afford new stationery, he wrote on the verso side of old manuscripts.", "An outstanding warrant for assault and unpaid debts led to his being a fugitive in New York City for a while.", "Several people, including his brother James Mills Peirce and his neighbors, relatives of Gifford Pinchot, settled his debts and paid his property taxes and mortgage.Peirce did some scientific and engineering consulting and wrote much for meager pay, mainly encyclopedic dictionary entries, and reviews for ''The Nation'' (with whose editor, Wendell Phillips Garrison, he became friendly).", "He did translations for the Smithsonian Institution, at its director Samuel Langley's instigation.", "Peirce also did substantial mathematical calculations for Langley's research on powered flight.", "Hoping to make money, Peirce tried inventing.", "He began but did not complete several books.", "In 1888, President Grover Cleveland appointed him to the Assay Commission.From 1890 on, he had a friend and admirer in Judge Francis C. Russell of Chicago, who introduced Peirce to editor Paul Carus and owner Edward C. Hegeler of the pioneering American philosophy journal ''The Monist'', which eventually published at least 14 articles by Peirce.", "He wrote many texts in James Mark Baldwin's ''Dictionary of Philosophy and Psychology'' (1901–1905); half of those credited to him appear to have been written actually by Christine Ladd-Franklin under his supervision.", "He applied in 1902 to the newly formed Carnegie Institution for a grant to write a systematic book describing his life's work.", "The application was doomed; his nemesis, Newcomb, served on the Carnegie Institution executive committee, and its president had been president of Johns Hopkins at the time of Peirce's dismissal.The one who did the most to help Peirce in these desperate times was his old friend William James, dedicating his ''Will to Believe'' (1897) to Peirce, and arranging for Peirce to be paid to give two series of lectures at or near Harvard (1898 and 1903).", "Most important, each year from 1907 until James's death in 1910, James wrote to his friends in the Boston intelligentsia to request financial aid for Peirce; the fund continued even after James died.", "Peirce reciprocated by designating James's eldest son as his heir should Juliette predecease him.", "It has been believed that this was also why Peirce used \"Santiago\" (\"St. James\" in English) as a middle name, but he appeared in print as early as 1890 as Charles Santiago Peirce.", "(See Charles Santiago Sanders Peirce for discussion and references)." ], [ "Death and legacy", "Peirce died destitute in Milford, Pennsylvania, twenty years before his widow.", "Juliette Peirce kept the urn with Peirce's ashes at Arisbe.", "In 1934, Pennsylvania Governor Gifford Pinchot arranged for Juliette's burial in Milford Cemetery.", "The urn with Peirce's ashes was interred with Juliette.Bertrand Russell (1959) wrote \"Beyond doubt ... he was one of the most original minds of the later nineteenth century and certainly the greatest American thinker ever\".", "Russell and Whitehead's ''Principia Mathematica'', published from 1910 to 1913, does not mention Peirce (Peirce's work was not widely known until later).", "A. N. Whitehead, while reading some of Peirce's unpublished manuscripts soon after arriving at Harvard in 1924, was struck by how Peirce had anticipated his own \"process\" thinking.", "(On Peirce and process metaphysics, see Lowe 1964.)", "Karl Popper viewed Peirce as \"one of the greatest philosophers of all times\".", "Yet Peirce's achievements were not immediately recognized.", "His imposing contemporaries William James and Josiah Royce admired him and Cassius Jackson Keyser, at Columbia and C. K. Ogden, wrote about Peirce with respect but to no immediate effect.The first scholar to give Peirce his considered professional attention was Royce's student Morris Raphael Cohen, the editor of an anthology of Peirce's writings entitled ''Chance, Love, and Logic'' (1923), and the author of the first bibliography of Peirce's scattered writings.", "John Dewey studied under Peirce at Johns Hopkins.", "From 1916 onward, Dewey's writings repeatedly mention Peirce with deference.", "His 1938 ''Logic: The Theory of Inquiry'' is much influenced by Peirce.", "The publication of the first six volumes of ''Collected Papers'' (1931–1935), the most important event to date in Peirce studies and one that Cohen made possible by raising the needed funds, did not prompt an outpouring of secondary studies.", "The editors of those volumes, Charles Hartshorne and Paul Weiss, did not become Peirce specialists.", "Early landmarks of the secondary literature include the monographs by Buchler (1939), Feibleman (1946), and Goudge (1950), the 1941 PhD thesis by Arthur W. Burks (who went on to edit volumes 7 and 8), and the studies edited by Wiener and Young (1952).", "The Charles S. Peirce Society was founded in 1946.Its ''Transactions'', an academic quarterly specializing in Peirce's pragmatism and American philosophy has appeared since 1965.", "(See Phillips 2014, 62 for discussion of Peirce and Dewey relative to transactionalism.", ")By 1943 such was Peirce's reputation, in the US at least, that ''Webster's Biographical Dictionary'' said that Peirce was \"now regarded as the most original thinker and greatest logician of his time\".In 1949, while doing unrelated archival work, the historian of mathematics Carolyn Eisele (1902–2000) chanced on an autograph letter by Peirce.", "So began her forty years of research on Peirce, “the mathematician and scientist,” culminating in Eisele (1976, 1979, 1985).", "Beginning around 1960, the philosopher and historian of ideas Max Fisch (1900–1995) emerged as an authority on Peirce (Fisch, 1986).", "He includes many of his relevant articles in a survey (Fisch 1986: 422–448) of the impact of Peirce's thought through 1983.Peirce has gained an international following, marked by university research centers devoted to Peirce studies and pragmatism in Brazil (CeneP/CIEP), Finland (HPRC and ), Germany (Wirth's group, Hoffman's and Otte's group, and Deuser's and Härle's group), France (L'I.R.S.C.E.", "), Spain (GEP), and Italy (CSP).", "His writings have been translated into several languages, including German, French, Finnish, Spanish, and Swedish.", "Since 1950, there have been French, Italian, Spanish, British, and Brazilian Peirce scholars of note.", "For many years, the North American philosophy department most devoted to Peirce was the University of Toronto, thanks in part to the leadership of Thomas Goudge and David Savan.", "In recent years, U.S. Peirce scholars have clustered at Indiana University – Purdue University Indianapolis, home of the Peirce Edition Project (PEP) –, and Pennsylvania State University.In recent years, Peirce's trichotomy of signs is exploited by a growing number of practitioners for marketing and design tasks.John Deely writes that Peirce was the last of the \"moderns\" and \"first of the postmoderns\".", "He lauds Peirce's doctrine of signs as a contribution to the dawn of the Postmodern epoch.", "Deely additionally comments that \"Peirce stands...in a position analogous to the position occupied by Augustine as last of the Western Fathers and first of the medievals\"." ], [ "Works", "Peirce's reputation rests largely on academic papers published in American scientific and scholarly journals such as ''Proceedings of the American Academy of Arts and Sciences'', the ''Journal of Speculative Philosophy'', ''The Monist'', ''Popular Science Monthly'', the ''American Journal of Mathematics'', ''Memoirs of the National Academy of Sciences'', ''The Nation'', and others.", "See Articles by Peirce, published in his lifetime for an extensive list with links to them online.", "The only full-length book (neither extract nor pamphlet) that Peirce authored and saw published in his lifetime was ''Photometric Researches'' (1878), a 181-page monograph on the applications of spectrographic methods to astronomy.", "While at Johns Hopkins, he edited ''Studies in Logic'' (1883), containing chapters by himself and his graduate students.", "Besides lectures during his years (1879–1884) as lecturer in Logic at Johns Hopkins, he gave at least nine series of lectures, many now published; see Lectures by Peirce.After Peirce's death, Harvard University obtained from Peirce's widow the papers found in his study, but did not microfilm them until 1964.Only after Richard Robin (1967) catalogued this ''Nachlass'' did it become clear that Peirce had left approximately 1,650 unpublished manuscripts, totaling over 100,000 pages, mostly still unpublished except on microfilm.", "On the vicissitudes of Peirce's papers, see Houser (1989).", "Reportedly the papers remain in unsatisfactory condition.The first published anthology of Peirce's articles was the one-volume ''Chance, Love and Logic: Philosophical Essays'', edited by Morris Raphael Cohen, 1923, still in print.", "Other one-volume anthologies were published in 1940, 1957, 1958, 1972, 1994, and 2009, most still in print.", "The main posthumous editions of Peirce's works in their long trek to light, often multi-volume, and some still in print, have included:1931–1958: ''Collected Papers of Charles Sanders Peirce'' (CP), 8 volumes, includes many published works, along with a selection of previously unpublished work and a smattering of his correspondence.", "This long-time standard edition drawn from Peirce's work from the 1860s to 1913 remains the most comprehensive survey of his prolific output from 1893 to 1913.It is organized thematically, but texts (including lecture series) are often split up across volumes, while texts from various stages in Peirce's development are often combined, requiring frequent visits to editors' notes.", "Edited (1–6) by Charles Hartshorne and Paul Weiss and (7–8) by Arthur Burks, in print and online.1975–1987: ''Charles Sanders Peirce: Contributions to'' The Nation, 4 volumes, includes Peirce's more than 300 reviews and articles published 1869–1908 in ''The Nation''.", "Edited by Kenneth Laine Ketner and James Edward Cook, online.1976: ''The New Elements of Mathematics by Charles S. Peirce'', 4 volumes in 5, included many previously unpublished Peirce manuscripts on mathematical subjects, along with Peirce's important published mathematical articles.", "Edited by Carolyn Eisele, back in print.1977: ''Semiotic and Significs: The Correspondence between C. S. Peirce and Victoria Lady Welby'' (2nd edition 2001), included Peirce's entire correspondence (1903–1912) with Victoria, Lady Welby.", "Peirce's other published correspondence is largely limited to the 14 letters included in volume 8 of the ''Collected Papers'', and the 20-odd pre-1890 items included so far in the ''Writings''.", "Edited by Charles S. Hardwick with James Cook, out of print.1982–now: ''Writings of Charles S. Peirce, A Chronological Edition'' (W), Volumes 1–6 & 8, of a projected 30.The limited coverage, and defective editing and organization, of the ''Collected Papers'' led Max Fisch and others in the 1970s to found the Peirce Edition Project (PEP), whose mission is to prepare a more complete critical chronological edition.", "Only seven volumes have appeared to date, but they cover the period from 1859 to 1892, when Peirce carried out much of his best-known work.", "''Writings of Charles S. Peirce'', 8 was published in November 2010; and work continues on ''Writings of Charles S. Peirce'', 7, 9, and 11.In print and online.1985: ''Historical Perspectives on Peirce's Logic of Science: A History of Science'', 2 volumes.", "Auspitz has said, \"The extent of Peirce's immersion in the science of his day is evident in his reviews in the ''Nation'' ... and in his papers, grant applications, and publishers' prospectuses in the history and practice of science\", referring latterly to ''Historical Perspectives''.", "Edited by Carolyn Eisele, back in print.1992: ''Reasoning and the Logic of Things'' collects in one place Peirce's 1898 series of lectures invited by William James.", "Edited by Kenneth Laine Ketner, with commentary by Hilary Putnam, in print.1992–1998: ''The Essential Peirce'' (EP), 2 volumes, is an important recent sampler of Peirce's philosophical writings.", "Edited (1) by Nathan Hauser and Christian Kloesel and (2) by ''Peirce Edition Project'' editors, in print.1997: ''Pragmatism as a Principle and Method of Right Thinking'' collects Peirce's 1903 Harvard \"Lectures on Pragmatism\" in a study edition, including drafts, of Peirce's lecture manuscripts, which had been previously published in abridged form; the lectures now also appear in ''The Essential Peirce'', 2.Edited by Patricia Ann Turisi, in print.2010: ''Philosophy of Mathematics: Selected Writings'' collects important writings by Peirce on the subject, many not previously in print.", "Edited by Matthew E. Moore, in print." ], [ "Mathematics", "Peirce's most important work in pure mathematics was in logical and foundational areas.", "He also worked on linear algebra, matrices, various geometries, topology and Listing numbers, Bell numbers, graphs, the four-color problem, and the nature of continuity.He worked on applied mathematics in economics, engineering, and map projections, and was especially active in probability and statistics.", ";Discoveries↓ The Peirce arrow, symbol for \"(neither) ... '''nor''' ...\", also called the ''Quine dagger''Peirce made a number of striking discoveries in formal logic and foundational mathematics, nearly all of which came to be appreciated only long after he died:In 1860 he suggested a cardinal arithmetic for infinite numbers, years before any work by Georg Cantor (who completed his dissertation in 1867) and without access to Bernard Bolzano's 1851 (posthumous) ''Paradoxien des Unendlichen''.In 1880–1881 he showed how Boolean algebra could be done via a repeated sufficient single binary operation (logical NOR), anticipating Henry M. Sheffer by 33 years.", "(See also De Morgan's Laws.", ")In 1881 he set out the axiomatization of natural number arithmetic, a few years before Richard Dedekind and Giuseppe Peano.", "In the same paper Peirce gave, years before Dedekind, the first purely cardinal definition of a finite set in the sense now known as \"Dedekind-finite\", and implied by the same stroke an important formal definition of an infinite set (Dedekind-infinite), as a set that can be put into a one-to-one correspondence with one of its proper subsets.In 1885 he distinguished between first-order and second-order quantification.", "In the same paper he set out what can be read as the first (primitive) axiomatic set theory, anticipating Zermelo by about two decades (Brady 2000, pp.", "132–133).Existential graphs: Alpha graphsIn 1886, he saw that Boolean calculations could be carried out via electrical switches, anticipating Claude Shannon by more than 50 years.", "By the later 1890s he was devising existential graphs, a diagrammatic notation for the predicate calculus.", "Based on them are John F. Sowa's conceptual graphs and Sun-Joo Shin's diagrammatic reasoning.", ";''The New Elements of Mathematics''Peirce wrote drafts for an introductory textbook, with the working title ''The New Elements of Mathematics'', that presented mathematics from an original standpoint.", "Those drafts and many other of his previously unpublished mathematical manuscripts finally appeared in ''The New Elements of Mathematics by Charles S. Peirce'' (1976), edited by mathematician Carolyn Eisele.", ";Nature of mathematicsPeirce agreed with Auguste Comte in regarding mathematics as more basic than philosophy and the special sciences (of nature and mind).", "Peirce classified mathematics into three subareas: (1) mathematics of logic, (2) discrete series, and (3) pseudo-continua (as he called them, including the real numbers) and continua.", "Influenced by his father Benjamin, Peirce argued that mathematics studies purely hypothetical objects and is not just the science of quantity but is more broadly the science which draws necessary conclusions; that mathematics aids logic, not vice versa; and that logic itself is part of philosophy and is the science ''about'' drawing conclusions necessary and otherwise.===Mathematics of logic===Mathematical logic and foundations, some noted articles* \"On an Improvement in Boole's Calculus of Logic\" (1867)* \"Description of a Notation for the Logic of Relatives\" (1870)* \"On the Algebra of Logic\" (1880)* \"A Boolian Algebra with One Constant\" (1880 MS)* \"On the Logic of Number\" (1881)* \"Note B: The Logic of Relatives\" (1883)* \"On the Algebra of Logic: A Contribution to the Philosophy of Notation\" (1884/1885)* \"The Logic of Relatives\" (1897)* \"The Simplest Mathematics\" (1902 MS)* \"Prolegomena to an Apology for Pragmaticism\" (1906, on existential graphs)===Probability and statistics===Peirce held that science achieves statistical probabilities, not certainties, and that spontaneity (absolute chance) is real (see Tychism on his view).", "Most of his statistical writings promote the frequency interpretation of probability (objective ratios of cases), and many of his writings express skepticism about (and criticize the use of) probability when such models are not based on objective randomization.", "Though Peirce was largely a frequentist, his possible world semantics introduced the \"propensity\" theory of probability before Karl Popper.", "Peirce (sometimes with Joseph Jastrow) investigated the probability judgments of experimental subjects, \"perhaps the very first\" elicitation and estimation of subjective probabilities in experimental psychology and (what came to be called) Bayesian statistics.Peirce was one of the founders of statistics.", "He formulated modern statistics in \"Illustrations of the Logic of Science\" (1877–1878) and \"A Theory of Probable Inference\" (1883).", "With a repeated measures design, Charles Sanders Peirce and Joseph Jastrow introduced blinded, controlled randomized experiments in 1884 (Hacking 1990:205) (before Ronald A. Fisher).", "He invented optimal design for experiments on gravity, in which he \"corrected the means\".", "He used correlation and smoothing.", "Peirce extended the work on outliers by Benjamin Peirce, his father.", "He introduced terms \"confidence\" and \"likelihood\" (before Jerzy Neyman and Fisher).", "(See Stephen Stigler's historical books and Ian Hacking 1990.)" ], [ "Philosophy", "Peirce was a working scientist for 30 years, and arguably was a professional philosopher only during the five years he lectured at Johns Hopkins.", "He learned philosophy mainly by reading, each day, a few pages of Immanuel Kant's ''Critique of Pure Reason'', in the original German, while a Harvard undergraduate.", "His writings bear on a wide array of disciplines, including mathematics, logic, philosophy, statistics, astronomy, metrology, geodesy, experimental psychology, economics, linguistics, and the history and philosophy of science.", "This work has enjoyed renewed interest and approval, a revival inspired not only by his anticipations of recent scientific developments but also by his demonstration of how philosophy can be applied effectively to human problems.Peirce's philosophy includes (see below in related sections) a pervasive three-category system: belief that truth is immutable and is both independent from actual opinion (fallibilism) and discoverable (no radical skepticism), logic as formal semiotic on signs, on arguments, and on inquiry's ways—including philosophical pragmatism (which he founded), critical common-sensism, and scientific method—and, in metaphysics: Scholastic realism, e.g.", "John Duns Scotus, belief in God, freedom, and at least an attenuated immortality, objective idealism, and belief in the reality of continuity and of absolute chance, mechanical necessity, and creative love.", "In his work, fallibilism and pragmatism may seem to work somewhat like skepticism and positivism, respectively, in others' work.", "However, for Peirce, fallibilism is balanced by an anti-skepticism and is a basis for belief in the reality of absolute chance and of continuity, and pragmatism commits one to anti-nominalist belief in the reality of the general (CP 5.453–457).For Peirce, First Philosophy, which he also called cenoscopy, is less basic than mathematics and more basic than the special sciences (of nature and mind).", "It studies positive phenomena in general, phenomena available to any person at any waking moment, and does not settle questions by resorting to special experiences.", "He divided such philosophy into (1) phenomenology (which he also called phaneroscopy or categorics), (2) normative sciences (esthetics, ethics, and logic), and (3) metaphysics; his views on them are discussed in order below.===Pragmatism===Some noted articles and lectures* Illustrations of the Logic of Science (1877–1878): inquiry, pragmatism, statistics, inference# The Fixation of Belief (1877)# How to Make Our Ideas Clear (1878)# The Doctrine of Chances (1878)# The Probability of Induction (1878)# The Order of Nature (1878)# Deduction, Induction, and Hypothesis (1878)* The Harvard lectures on pragmatism (1903)* What Pragmatism Is (1905)* Issues of Pragmaticism (1905)* Pragmatism (1907 MS in ''The Essential Peirce'', 2) Peirce's recipe for pragmatic thinking, which he called ''pragmatism'' and, later, ''pragmaticism'', is recapitulated in several versions of the so-called ''pragmatic maxim''.", "Here is one of his more emphatic reiterations of it:As a movement, pragmatism began in the early 1870s in discussions among Peirce, William James, and others in the Metaphysical Club.", "James among others regarded some articles by Peirce such as \"The Fixation of Belief\" (1877) and especially \"How to Make Our Ideas Clear\" (1878) as foundational to pragmatism.", "Peirce (CP 5.11–12), like James (''Pragmatism: A New Name for Some Old Ways of Thinking'', 1907), saw pragmatism as embodying familiar attitudes, in philosophy and elsewhere, elaborated into a new deliberate method for fruitful thinking about problems.", "Peirce differed from James and the early John Dewey, in some of their tangential enthusiasms, in being decidedly more rationalistic and realistic, in several senses of those terms, throughout the preponderance of his own philosophical moods.In 1905 Peirce coined the new name pragmaticism \"for the precise purpose of expressing the original definition\", saying that \"all went happily\" with James's and F.C.S.", "Schiller's variant uses of the old name \"pragmatism\" and that he coined the new name because of the old name's growing use in \"literary journals, where it gets abused\".", "Yet he cited as causes, in a 1906 manuscript, his differences with James and Schiller and, in a 1908 publication, his differences with James as well as literary author Giovanni Papini's declaration of pragmatism's indefinability.", "Peirce in any case regarded his views that truth is immutable and infinity is real, as being opposed by the other pragmatists, but he remained allied with them on other issues.Pragmatism begins with the idea that belief is that on which one is prepared to act.", "Peirce's pragmatism is a method of clarification of conceptions of objects.", "It equates any conception of an object to a conception of that object's effects to a general extent of the effects' conceivable implications for informed practice.", "It is a method of sorting out conceptual confusions occasioned, for example, by distinctions that make (sometimes needed) formal yet not practical differences.", "He formulated both pragmatism and statistical principles as aspects of scientific logic, in his \"Illustrations of the Logic of Science\" series of articles.", "In the second one, \"How to Make Our Ideas Clear\", Peirce discussed three grades of clearness of conception:# Clearness of a conception familiar and readily used, even if unanalyzed and undeveloped.# Clearness of a conception in virtue of clearness of its parts, in virtue of which logicians called an idea \"distinct\", that is, clarified by analysis of just what makes it applicable.", "Elsewhere, echoing Kant, Peirce called a likewise distinct definition \"nominal\" (CP 5.553).# Clearness in virtue of clearness of conceivable practical implications of the object's conceived effects, such that fosters fruitful reasoning, especially on difficult problems.", "Here he introduced that which he later called the pragmatic maxim.By way of example of how to clarify conceptions, he addressed conceptions about truth and the real as questions of the presuppositions of reasoning in general.", "In clearness's second grade (the \"nominal\" grade), he defined truth as a sign's correspondence to its object, and the real as the object of such correspondence, such that truth and the real are independent of that which you or I or any actual, definite community of inquirers think.", "After that needful but confined step, next in clearness's third grade (the pragmatic, practice-oriented grade) he defined truth as that opinion which ''would'' be reached, sooner or later but still inevitably, by research taken far enough, such that the real does depend on that ideal final opinion—a dependence to which he appeals in theoretical arguments elsewhere, for instance for the long-run validity of the rule of induction.", "Peirce argued that even to argue against the independence and discoverability of truth and the real is to presuppose that there is, about that very question under argument, a truth with just such independence and discoverability.Peirce said that a conception's meaning consists in \"all general modes of rational conduct\" implied by \"acceptance\" of the conception—that is, if one were to accept, first of all, the conception as true, then what could one conceive to be consequent general modes of rational conduct by all who accept the conception as true?—the whole of such consequent general modes is the whole meaning.", "His pragmatism does not equate a conception's meaning, its intellectual purport, with the conceived benefit or cost of the conception itself, like a meme (or, say, propaganda), outside the perspective of its being true, nor, since a conception is general, is its meaning equated with any definite set of actual consequences or upshots corroborating or undermining the conception or its worth.", "His pragmatism also bears no resemblance to \"vulgar\" pragmatism, which misleadingly connotes a ruthless and Machiavellian search for mercenary or political advantage.", "Instead the pragmatic maxim is the heart of his pragmatism as a method of experimentational mental reflection arriving at conceptions in terms of conceivable confirmatory and disconfirmatory circumstances—a method hospitable to the formation of explanatory hypotheses, and conducive to the use and improvement of verification.Peirce's pragmatism, as method and theory of definitions and conceptual clearness, is part of his theory of inquiry, which he variously called speculative, general, formal or universal rhetoric or simply methodeutic.", "He applied his pragmatism as a method throughout his work.====Theory of inquiry====In \"The Fixation of Belief\" (1877), Peirce gives his take on the psychological origin and aim of inquiry.", "On his view, individuals are motivated to inquiry by desire to escape the feelings of anxiety and unease which Peirce takes to be characteristic of the state of doubt.", "Doubt is described by Peirce as an \"uneasy and dissatisfied state from which we struggle to free ourselves and pass into the state of belief.\"", "Peirce uses words like \"irritation\" to describe the experience of being in doubt and to explain why he thinks we find such experiences to be motivating.", "The irritating feeling of doubt is appeased, Peirce says, through our efforts to achieve a settled state of satisfaction with what we land on as our answer to the question which led to that doubt in the first place.", "This settled state, namely, belief, is described by Peirce as \"a calm and satisfactory state which we do not wish to avoid.\"", "Our efforts to achieve the satisfaction of belief, by whichever methods we may pursue, are what Peirce calls \"inquiry\".", "Four methods which Peirce describes as having been actually pursued throughout the history of thought are summarized below in the section after next.", "=====Critical common-sensism=====Critical common-sensism, treated by Peirce as a consequence of his pragmatism, is his combination of Thomas Reid's common-sense philosophy with a fallibilism that recognizes that propositions of our more or less vague common sense now indubitable may later come into question, for example because of transformations of our world through science.", "It includes efforts to work up in tests genuine doubts for a core group of common indubitables that vary slowly if at all.=====Rival methods of inquiry=====In \"The Fixation of Belief\" (1877), Peirce described inquiry in general not as the pursuit of truth ''per se'' but as the struggle to move from irritating, inhibitory doubt born of surprise, disagreement, and the like, and to reach a secure belief, belief being that on which one is prepared to act.", "That let Peirce frame scientific inquiry as part of a broader spectrum and as spurred, like inquiry generally, by actual doubt, not mere verbal, quarrelsome, or hyperbolic doubt, which he held to be fruitless.", "Peirce sketched four methods of settling opinion, ordered from least to most successful:# The method of (policy of sticking to initial belief) – which brings comforts and decisiveness but leads to trying to ignore contrary information and others' views as if truth were intrinsically private, not public.", "The method goes against the social impulse and easily falters since one may well notice when another's opinion seems as good as one's own initial opinion.", "Its successes can be brilliant but tend to be transitory.# The method of – which overcomes disagreements but sometimes brutally.", "Its successes can be majestic and long-lasting, but it cannot regulate people thoroughly enough to withstand doubts indefinitely, especially when people learn about other societies present and past.# The method of the – which promotes conformity less brutally but fosters opinions as something like tastes, arising in conversation and comparisons of perspectives in terms of \"what is agreeable to reason\".", "Thereby it depends on fashion in paradigms and goes in circles over time.", "It is more intellectual and respectable but, like the first two methods, sustains accidental and capricious beliefs, destining some minds to doubt it.# The method of – wherein inquiry supposes that the real is discoverable but independent of particular opinion, such that, unlike in the other methods, inquiry can, by its own account, go wrong (fallibilism), not only right, and thus purposely tests itself and criticizes, corrects, and improves itself.Peirce held that, in practical affairs, slow and stumbling ratiocination is often dangerously inferior to instinct and traditional sentiment, and that the scientific method is best suited to theoretical research, which in turn should not be trammeled by the other methods and practical ends; reason's \"first rule\" is that, in order to learn, one must desire to learn and, as a corollary, must not block the way of inquiry.", "Scientific method excels over the others finally by being deliberately designed to arrive—eventually—at the most secure beliefs, upon which the most successful practices can be based.", "Starting from the idea that people seek not truth ''per se'' but instead to subdue irritating, inhibitory doubt, Peirce showed how, through the struggle, some can come to submit to truth for the sake of belief's integrity, seek as truth the guidance of potential conduct correctly to its given goal, and wed themselves to the scientific method.=====Scientific method=====Insofar as clarification by pragmatic reflection suits explanatory hypotheses and fosters predictions and testing, pragmatism points beyond the usual duo of foundational alternatives: deduction from self-evident truths, or ''rationalism''; and induction from experiential phenomena, or ''empiricism''.Based on his critique of three modes of argument and different from either foundationalism or coherentism, Peirce's approach seeks to justify claims by a three-phase dynamic of inquiry:# Active, abductive genesis of theory, with no prior assurance of truth;# Deductive application of the contingent theory so as to clarify its practical implications;# Inductive testing and evaluation of the utility of the provisional theory in anticipation of future experience, in both senses: ''prediction'' and ''control''.Thereby, Peirce devised an approach to inquiry far more solid than the flatter image of inductive generalization ''simpliciter'', which is a mere re-labeling of phenomenological patterns.", "Peirce's pragmatism was the first time the scientific method was proposed as an epistemology for philosophical questions.A theory that succeeds better than its rivals in predicting and controlling our world is said to be nearer the truth.", "This is an operational notion of truth used by scientists.Peirce extracted the pragmatic model or theory of inquiry from its raw materials in classical logic and refined it in parallel with the early development of symbolic logic to address problems about the nature of scientific reasoning.Abduction, deduction, and induction make incomplete sense in isolation from one another but comprise a cycle understandable as a whole insofar as they collaborate toward the common end of inquiry.", "In the pragmatic way of thinking about conceivable practical implications, every thing has a purpose, and, as possible, its purpose should first be denoted.", "Abduction hypothesizes an explanation for deduction to clarify into implications to be tested so that induction can evaluate the hypothesis, in the struggle to move from troublesome uncertainty to more secure belief.", "No matter how traditional and needful it is to study the modes of inference in abstraction from one another, the integrity of inquiry strongly limits the effective modularity of its principal components.Peirce's outline of the scientific method in §III–IV of \"A Neglected Argument\" is summarized below (except as otherwise noted).", "There he also reviewed plausibility and inductive precision (issues of critique of arguments).1.", "(or retroductive) phase.", "Guessing, inference to explanatory hypotheses for selection of those best worth trying.", "From abduction, Peirce distinguishes induction as inferring, on the basis of tests, the proportion of truth in the hypothesis.", "Every inquiry, whether into ideas, brute facts, or norms and laws, arises from surprising observations in one or more of those realms (and for example at any stage of an inquiry already underway).", "All explanatory content of theories comes from abduction, which guesses a new or outside idea so as to account in a simple, economical way for a surprising or complicated phenomenon.", "The modicum of success in our guesses far exceeds that of random luck, and seems born of attunement to nature by developed or inherent instincts, especially insofar as best guesses are optimally plausible and simple in the sense of the \"facile and natural\", as by Galileo's natural light of reason and as distinct from \"logical simplicity\".", "Abduction is the most fertile but least secure mode of inference.", "Its general rationale is inductive: it succeeds often enough and it has no substitute in expediting us toward new truths.", "In 1903, Peirce called pragmatism \"the logic of abduction\".", "Coordinative method leads from abducting a plausible hypothesis to judging it for its testability and for how its trial would economize inquiry itself.", "The hypothesis, being insecure, needs to have practical implications leading at least to mental tests and, in science, lending themselves to scientific tests.", "A simple but unlikely guess, if not costly to test for falsity, may belong first in line for testing.", "A guess is intrinsically worth testing if it has plausibility or reasoned objective probability, while subjective likelihood, though reasoned, can be misleadingly seductive.", "Guesses can be selected for trial strategically, for their caution (for which Peirce gave as example the game of Twenty Questions), breadth, or incomplexity.", "One can discover only that which would be revealed through their sufficient experience anyway, and so the point is to expedite it; economy of research demands the leap, so to speak, of abduction and governs its art.2.phase.", "Two stages::i. Explication.", "Not clearly premised, but a deductive analysis of the hypothesis so as to render its parts as clear as possible.:ii.", "Demonstration: Deductive Argumentation, Euclidean in procedure.", "Explicit deduction of consequences of the hypothesis as predictions about evidence to be found.", "Corollarial or, if needed, Theorematic.3.phase.", "Evaluation of the hypothesis, inferring from observational or experimental tests of its deduced consequences.", "The long-run validity of the rule of induction is deducible from the principle (presuppositional to reasoning in general) that the real \"is only the object of the final opinion to which sufficient investigation would lead\"; in other words, anything excluding such a process would never be real.", "Induction involving the ongoing accumulation of evidence follows \"a method which, sufficiently persisted in\", will \"diminish the error below any predesignate degree\".", "Three stages::i.", "Classification.", "Not clearly premised, but an inductive classing of objects of experience under general ideas.:ii.", "Probation: direct Inductive Argumentation.", "Crude or Gradual in procedure.", "Crude Induction, founded on experience in one mass (CP 2.759), presumes that future experience on a question will not differ utterly from all past experience (CP 2.756).", "Gradual Induction makes a new estimate of the proportion of truth in the hypothesis after each test, and is Qualitative or Quantitative.", "Qualitative Gradual Induction depends on estimating the relative evident weights of the various qualities of the subject class under investigation (CP 2.759; see also ''Collected Papers of Charles Sanders Peirce'', 7.114–120).", "Quantitative Gradual Induction depends on how often, in a fair sample of instances of ''S'', ''S'' is found actually accompanied by ''P'' that was predicted for ''S'' (CP 2.758).", "It depends on measurements, or statistics, or counting.:iii.", "Sentential Induction.", "\"...which, by Inductive reasonings, appraises the different Probations singly, then their combinations, then makes self-appraisal of these very appraisals themselves, and passes final judgment on the whole result\".=====Against Cartesianism=====Peirce drew on the methodological implications of the four incapacities—no genuine introspection, no intuition in the sense of non-inferential cognition, no thought but in signs, and no conception of the absolutely incognizable—to attack philosophical Cartesianism, of which he said that:# \"It teaches that philosophy must begin in universal doubt\" – when, instead, we start with preconceptions, \"prejudices ... which it does not occur to us ''can'' be questioned\", though we may find reason to question them later.", "\"Let us not pretend to doubt in philosophy what we do not doubt in our hearts.", "\"# \"It teaches that the ultimate test of certainty is...in the individual consciousness\" – when, instead, in science a theory stays on probation till agreement is reached, then it has no actual doubters left.", "No lone individual can reasonably hope to fulfill philosophy's multi-generational dream.", "When \"candid and disciplined minds\" continue to disagree on a theoretical issue, even the theory's author should feel doubts about it.# It trusts to \"a single thread of inference depending often upon inconspicuous premisses\" – when, instead, philosophy should, \"like the successful sciences\", proceed only from tangible, scrutinizable premisses and trust not to any one argument but instead to \"the multitude and variety of its arguments\" as forming, not a chain at least as weak as its weakest link, but \"a cable whose fibers\", soever \"slender, are sufficiently numerous and intimately connected\".# It renders many facts \"absolutely inexplicable, unless to say that 'God makes them so' is to be regarded as an explanation\" – when, instead, philosophy should avoid being \"unidealistic\", misbelieving that something real can defy or evade all possible ideas, and supposing, inevitably, \"some absolutely inexplicable, unanalyzable ultimate\", which explanatory surmise explains nothing and so is inadmissible.===Theory of categories===On May 14, 1867, the 27-year-old Peirce presented a paper entitled \"On a New List of Categories\" to the American Academy of Arts and Sciences, which published it the following year.", "The paper outlined a theory of predication, involving three universal categories that Peirce developed in response to reading Aristotle, Immanuel Kant, and G. W. F. Hegel, categories that Peirce applied throughout his work for the rest of his life.", "Peirce scholars generally regard the \"New List\" as foundational or breaking the ground for Peirce's \"architectonic\", his blueprint for a pragmatic philosophy.", "In the categories one will discern, concentrated, the pattern that one finds formed by the three grades of clearness in \"How To Make Our Ideas Clear\" (1878 paper foundational to pragmatism), and in numerous other trichotomies in his work.", "\"On a New List of Categories\" is cast as a Kantian deduction; it is short but dense and difficult to summarize.", "The following table is compiled from that and later works.", "In 1893, Peirce restated most of it for a less advanced audience.", "=== Logic, or semiotic ===In 1918 the logician C. I. Lewis wrote, \"The contributions of C.S.", "Peirce to symbolic logic are more numerous and varied than those of any other writer—at least in the nineteenth century.\"", "==== Relational logic ====Beginning with his first paper on the \"Logic of Relatives\" (1870), Peirce extended the theory of relations pioneered by Augustus De Morgan.", "Beginning in 1940, Alfred Tarski and his students rediscovered aspects of Peirce's larger vision of relational logic, developing the perspective of relation algebra.Relational logic gained applications.", "In mathematics, it influenced the abstract analysis of E. H. Moore and the lattice theory of Garrett Birkhoff.", "In computer science, the relational model for databases was developed with Peircean ideas in work of Edgar F. Codd, who was a doctoral student of Arthur W. Burks, a Peirce scholar.", "In economics, relational logic was used by Frank P. Ramsey, John von Neumann, and Paul Samuelson to study preferences and utility and by Kenneth J. Arrow in ''Social Choice and Individual Values'', following Arrow's association with Tarski at City College of New York.==== Quantifiers ====On Peirce and his contemporaries Ernst Schröder and Gottlob Frege, Hilary Putnam (1982) documented that Frege's work on the logic of quantifiers had little influence on his contemporaries, although it was published four years before the work of Peirce and his student Oscar Howard Mitchell.", "Putnam found that mathematicians and logicians learned about the logic of quantifiers through the independent work of Peirce and Mitchell, particularly through Peirce's \"On the Algebra of Logic: A Contribution to the Philosophy of Notation\" (1885), published in the premier American mathematical journal of the day, and cited by Peano and Schröder, among others, who ignored Frege.", "They also adopted and modified Peirce's notations, typographical variants of those now used.", "Peirce apparently was ignorant of Frege's work, despite their overlapping achievements in logic, philosophy of language, and the foundations of mathematics.Peirce's work on formal logic had admirers besides Ernst Schröder:* Philosophical algebraist William Kingdon Clifford and logician William Ernest Johnson, both British;* The Polish school of logic and foundational mathematics, including Alfred Tarski;* Arthur Prior, who praised and studied Peirce's logical work in a 1964 paper and in ''Formal Logic'' (saying on page 4 that Peirce \"perhaps had a keener eye for essentials than any other logician before or since\").=== Philosophy of logic ===A philosophy of logic, grounded in his categories and semiotic, can be extracted from Peirce's writings and, along with Peirce's logical work more generally, is exposited and defended in Hilary Putnam (1982); the Introduction in Nathan Houser ''et al.''", "(1997); and Randall Dipert's chapter in Cheryl Misak (2004).==== Logic as philosophical ====Peirce regarded logic ''per se'' as a division of philosophy, as a normative science based on esthetics and ethics, as more basic than metaphysics, and as \"the art of devising methods of research\".", "More generally, as inference, \"logic is rooted in the social principle\", since inference depends on a standpoint that, in a sense, is unlimited.", "Peirce called (with no sense of deprecation) \"mathematics of logic\" much of the kind of thing which, in current research and applications, is called simply \"logic\".", "He was productive in both (philosophical) logic and logic's mathematics, which were connected deeply in his work and thought.Peirce argued that logic is formal semiotic: the formal study of signs in the broadest sense, not only signs that are artificial, linguistic, or symbolic, but also signs that are semblances or are indexical such as reactions.", "Peirce held that \"all this universe is perfused with signs, if it is not composed exclusively of signs\", along with their representational and inferential relations.", "He argued that, since all thought takes time, all thought is in signs and sign processes (\"semiosis\") such as the inquiry process.", "He divided logic into: (1) speculative grammar, or stechiology, on how signs can be meaningful and, in relation to that, what kinds of signs there are, how they combine, and how some embody or incorporate others; (2) logical critic, or logic proper, on the modes of inference; and (3) speculative or universal rhetoric, or methodeutic, the philosophical theory of inquiry, including pragmatism.==== Presuppositions of logic ====In his \"F.R.L.\"", "First Rule of Logic (1899), Peirce states that the first, and \"in one sense, the sole\", rule of reason is that, ''to learn, one needs to desire to learn'' and desire it without resting satisfied with that which one is inclined to think.", "So, the first rule is, ''to wonder''.", "Peirce proceeds to a critical theme in research practices and the shaping of theories:...there follows one corollary which itself deserves to be inscribed upon every wall of the city of philosophy:::Do not block the way of inquiry.Peirce adds, that method and economy are best in research but no outright sin inheres in trying any theory in the sense that the investigation via its trial adoption can proceed unimpeded and undiscouraged, and that \"the one unpardonable offence\" is a philosophical barricade against truth's advance, an offense to which \"metaphysicians in all ages have shown themselves the most addicted\".", "Peirce in many writings holds that logic precedes metaphysics (ontological, religious, and physical).Peirce goes on to list four common barriers to inquiry: (1) Assertion of absolute certainty; (2) maintaining that something is absolutely unknowable; (3) maintaining that something is absolutely inexplicable because absolutely basic or ultimate; (4) holding that perfect exactitude is possible, especially such as to quite preclude unusual and anomalous phenomena.", "To refuse absolute theoretical certainty is the heart of ''fallibilism'', which Peirce unfolds into refusals to set up any of the listed barriers.", "Peirce elsewhere argues (1897) that logic's presupposition of fallibilism leads at length to the view that chance and continuity are very real (tychism and synechism).The First Rule of Logic pertains to the mind's presuppositions in undertaking reason and logic; presuppositions, for instance, that truth and the real do not depend on yours or my opinion of them but do depend on representational relation and consist in the destined end in investigation taken far enough (see below).", "He describes such ideas as, collectively, hopes which, in particular cases, one is unable seriously to doubt.==== Four incapacities ====The ''Journal of Speculative Philosophy'' series (1868–1869), including* Questions concerning certain Faculties claimed for Man (1868)* Some Consequences of Four Incapacities (1868)* Grounds of Validity of the Laws of Logic:Further Consequences of Four Incapacities (1869) In three articles in 1868–1869, Peirce rejected mere verbal or hyperbolic doubt and first or ultimate principles, and argued that we have (as he numbered them):# No power of Introspection.", "All knowledge of the internal world comes by hypothetical reasoning from known external facts.# No power of Intuition (cognition without logical determination by previous cognitions).", "No cognitive stage is absolutely first in a process.", "All mental action has the form of inference.# No power of thinking without signs.", "A cognition must be interpreted in a subsequent cognition in order to be a cognition at all.# No conception of the absolutely incognizable.", "(The above sense of the term \"intuition\" is almost Kant's, said Peirce.", "It differs from the current looser sense that encompasses instinctive or anyway half-conscious inference.", ")Peirce argued that those incapacities imply the reality of the general and of the continuous, the validity of the modes of reasoning, and the falsity of philosophical Cartesianism (see below).Peirce rejected the conception (usually ascribed to Kant) of the unknowable thing-in-itself and later said that to \"dismiss make-believes\" is a prerequisite for pragmatism.==== Logic as formal semiotic ====Peirce sought, through his wide-ranging studies through the decades, formal philosophical ways to articulate thought's processes, and also to explain the workings of science.", "These inextricably entangled questions of a dynamics of inquiry rooted in nature and nurture led him to develop his semiotic with very broadened conceptions of signs and inference, and, as its culmination, a theory of inquiry for the task of saying 'how science works' and devising research methods.", "This would be logic by the medieval definition taught for centuries: art of arts, science of sciences, having the way to the principles of all methods.", "Influences radiate from points on parallel lines of inquiry in Aristotle's work, in such ''loci'' as: the basic terminology of psychology in ''On the Soul''; the founding description of sign relations in ''On Interpretation''; and the differentiation of inference into three modes that are commonly translated into English as ''abduction'', ''deduction'', and ''induction'', in the ''Prior Analytics'', as well as inference by analogy (called ''paradeigma'' by Aristotle), which Peirce regarded as involving the other three modes.Peirce began writing on semiotic in the 1860s, around the time when he devised his system of three categories.", "He called it both ''semiotic'' and ''semeiotic''.", "Both are current in singular and plural.", "He based it on the conception of a triadic sign relation, and defined ''semiosis'' as \"action, or influence, which is, or involves, a cooperation of ''three'' subjects, such as a sign, its object, and its interpretant, this tri-relative influence not being in any way resolvable into actions between pairs\".", "As to signs in thought, Peirce emphasized the reverse: \"To say, therefore, that thought cannot happen in an instant, but requires a time, is but another way of saying that every thought must be interpreted in another, or that all thought is in signs.", "\"Peirce held that all thought is in signs, issuing in and from interpretation, where ''sign'' is the word for the broadest variety of conceivable semblances, diagrams, metaphors, symptoms, signals, designations, symbols, texts, even mental concepts and ideas, all as determinations of a mind or ''quasi-mind'', that which at least functions like a mind, as in the work of crystals or bees—the focus is on sign action in general rather than on psychology, linguistics, or social studies (fields which he also pursued).Inquiry is a kind of inference process, a manner of thinking and semiosis.", "Global divisions of ways for phenomena to stand as signs, and the subsumption of inquiry and thinking within inference as a sign process, enable the study of inquiry on semiotics' three levels:# Conditions for meaningfulness.", "Study of significatory elements and combinations, their grammar.# Validity, conditions for true representation.", "Critique of arguments in their various separate modes.# Conditions for determining interpretations.", "Methodology of inquiry in its mutually interacting modes.Peirce uses examples often from common experience, but defines and discusses such things as assertion and interpretation in terms of philosophical logic.", "In a formal vein, Peirce said:=== Signs ======= Sign relation ====Peirce's theory of signs is known to be one of the most complex semiotic theories due to its generalistic claim.", "Anything is a sign—not absolutely as itself, but instead in some relation or other.", "The ''sign relation'' is the key.", "It defines three roles encompassing (1) the sign, (2) the sign's subject matter, called its ''object'', and (3) the sign's meaning or ramification as formed into a kind of effect called its ''interpretant'' (a further sign, for example a translation).", "It is an irreducible ''triadic relation'', according to Peirce.", "The roles are distinct even when the things that fill those roles are not.", "The roles are but three; a sign of an object leads to one or more interpretants, and, as signs, they lead to further interpretants.", "''Extension × intension = information.''", "Two traditional approaches to sign relation, necessary though insufficient, are the way of ''extension'' (a sign's objects, also called breadth, denotation, or application) and the way of ''intension'' (the objects' characteristics, qualities, attributes referenced by the sign, also called depth, comprehension, significance, or connotation).", "Peirce adds a third, the way of ''information'', including change of information, to integrate the other two approaches into a unified whole.", "For example, because of the equation above, if a term's total amount of information stays the same, then the more that the term 'intends' or signifies about objects, the fewer are the objects to which the term 'extends' or applies.''Determination.''", "A sign depends on its object in such a way as to represent its object—the object enables and, in a sense, determines the sign.", "A physically causal sense of this stands out when a sign consists in an indicative reaction.", "The interpretant depends likewise on both the sign and the object—an object determines a sign to determine an interpretant.", "But this determination is not a succession of dyadic events, like a row of toppling dominoes; sign determination is triadic.", "For example, an interpretant does not merely represent something which represented an object; instead an interpretant represents something ''as'' a sign representing the object.", "The object (be it a quality or fact or law or even fictional) determines the sign to an interpretant through one's collateral experience with the object, in which the object is found or from which it is recalled, as when a sign consists in a chance semblance of an absent object.", "Peirce used the word \"determine\" not in a strictly deterministic sense, but in a sense of \"specializes\", ''bestimmt'', involving variable amount, like an influence.", "Peirce came to define representation and interpretation in terms of (triadic) determination.", "The object determines the sign to determine another sign—the interpretant—to be related to the object ''as the sign is related to the object'', hence the interpretant, fulfilling its function as sign of the object, determines a further interpretant sign.", "The process is logically structured to perpetuate itself, and is definitive of sign, object, and interpretant in general.==== Semiotic elements ====Peirce held there are exactly three basic elements in semiosis (sign action):# A ''sign'' (or ''representamen'') represents, in the broadest possible sense of \"represents\".", "It is something interpretable as saying something about something.", "It is not necessarily symbolic, linguistic, or artificial—a cloud might be a sign of rain for instance, or ruins the sign of ancient civilization.", "As Peirce sometimes put it (he defined ''sign'' at least 76 times), the sign stands ''for'' the object ''to'' the interpretant.", "A sign represents its object in some respect, which respect is the sign's ''ground''.# An ''object'' (or ''semiotic object'') is a subject matter of a sign and an interpretant.", "It can be anything thinkable, a quality, an occurrence, a rule, etc., even fictional, such as Prince Hamlet.", "All of those are special or partial objects.", "The object most accurately is the universe of discourse to which the partial or special object belongs.", "For instance, a perturbation of Pluto's orbit is a sign about Pluto but ultimately not only about Pluto.", "An object either (i) is ''immediate'' to a sign and is the object as represented in the sign or (ii) is a ''dynamic'' object, the object as it really is, on which the immediate object is founded \"as on bedrock\".# An ''interpretant'' (or ''interpretant sign'') is a sign's meaning or ramification as formed into a kind of idea or effect, an interpretation, human or otherwise.", "An interpretant is a sign (a) of the object and (b) of the interpretant's \"predecessor\" (the interpreted sign) as a sign of the same object.", "An interpretant either (i) is ''immediate'' to a sign and is a kind of quality or possibility such as a word's usual meaning, or (ii) is a ''dynamic'' interpretant, such as a state of agitation, or (iii) is a ''final'' or ''normal'' interpretant, a sum of the lessons which a sufficiently considered sign ''would'' have as effects on practice, and with which an actual interpretant may at most coincide.Some of the understanding needed by the mind depends on familiarity with the object.", "To know what a given sign denotes, the mind needs some experience of that sign's object, experience outside of, and collateral to, that sign or sign system.", "In that context Peirce speaks of collateral experience, collateral observation, collateral acquaintance, all in much the same terms.==== Classes of signs ====Among Peirce's many sign typologies, three stand out, interlocked.", "The first typology depends on the sign itself, the second on how the sign stands for its denoted object, and the third on how the sign stands for its object to its interpretant.", "Also, each of the three typologies is a three-way division, a trichotomy, via Peirce's three phenomenological categories: (1) quality of feeling, (2) reaction, resistance, and (3) representation, mediation.I.", "''Qualisign, sinsign, legisign'' (also called'' tone, token, type,'' and also called ''potisign, actisign, famisign''): This typology classifies every sign according to the sign's own phenomenological category—the qualisign is a quality, a possibility, a \"First\"; the sinsign is a reaction or resistance, a singular object, an actual event or fact, a \"Second\"; and the legisign is a habit, a rule, a representational relation, a \"Third\".II.", "''Icon, index, symbol'': This typology, the best known one, classifies every sign according to the category of the sign's way of denoting its object—the icon (also called semblance or likeness) by a quality of its own, the index by factual connection to its object, and the symbol by a habit or rule for its interpretant.III.", "''Rheme, dicisign, argument'' (also called ''sumisign, dicisign, suadisign,'' also ''seme, pheme, delome,'' and regarded as very broadened versions of the traditional ''term, proposition, argument''): This typology classifies every sign according to the category which the interpretant attributes to the sign's way of denoting its object—the rheme, for example a term, is a sign interpreted to represent its object in respect of quality; the dicisign, for example a proposition, is a sign interpreted to represent its object in respect of fact; and the argument is a sign interpreted to represent its object in respect of habit or law.", "This is the culminating typology of the three, where the sign is understood as a structural element of inference.Every sign belongs to one class or another within (I) ''and'' within (II) ''and'' within (III).", "Thus each of the three typologies is a three-valued parameter for every sign.", "The three parameters are not independent of each other; many co-classifications are absent, for reasons pertaining to the lack of either habit-taking or singular reaction in a quality, and the lack of habit-taking in a singular reaction.", "The result is not 27 but instead ten classes of signs fully specified at this level of analysis.=== Modes of inference ===Borrowing a brace of concepts from Aristotle, Peirce examined three basic modes of inference—''abduction'', ''deduction'', and ''induction''—in his \"critique of arguments\" or \"logic proper\".", "Peirce also called abduction \"retroduction\", \"presumption\", and, earliest of all, \"hypothesis\".", "He characterized it as guessing and as inference to an explanatory hypothesis.", "He sometimes expounded the modes of inference by transformations of the categorical syllogism Barbara (AAA), for example in \"Deduction, Induction, and Hypothesis\" (1878).", "He does this by rearranging the ''rule'' (Barbara's major premise), the ''case'' (Barbara's minor premise), and the ''result'' (Barbara's conclusion):Deduction.", "''Rule:'' All the beans from this bag are white.", "''Case:'' These beans are beans from this bag.", "''Result:'' These beans are white.Induction.", "''Case:'' These beans are randomly selected from this bag.", "''Result:'' These beans are white.", "''Rule:'' All the beans from this bag are white.Hypothesis (Abduction).", "''Rule:'' All the beans from this bag are white.", "''Result:'' These beans oddly are white.", "''Case:'' These beans are from this bag.Peirce 1883 in \"A Theory of Probable Inference\" (''Studies in Logic'') equated hypothetical inference with the induction of characters of objects (as he had done in effect before).", "Eventually dissatisfied, by 1900 he distinguished them once and for all and also wrote that he now took the syllogistic forms and the doctrine of logical extension and comprehension as being less basic than he had thought.", "In 1903 he presented the following logical form for abductive inference:The logical form does not also cover induction, since induction neither depends on surprise nor proposes a new idea for its conclusion.", "Induction seeks facts to test a hypothesis; abduction seeks a hypothesis to account for facts.", "\"Deduction proves that something ''must'' be; Induction shows that something ''actually is'' operative; Abduction merely suggests that something ''may be''.\"", "Peirce did not remain quite convinced that one logical form covers all abduction.", "In his methodeutic or theory of inquiry (see below), he portrayed abduction as an economic initiative to further inference and study, and portrayed all three modes as clarified by their coordination in essential roles in inquiry: hypothetical explanation, deductive prediction, inductive testing===Aesthetics and ethics===Peirce did not write extensively in aesthetics and ethics, but came by 1902 to hold that aesthetics, ethics, and logic, in that order, comprise the normative sciences.", "He characterized aesthetics as the study of the good (grasped as the admirable), and thus of the ends governing all conduct and thought.=== Metaphysics ===Some noted articles* The ''Monist'' Metaphysical Series (1891–1893)** The Architecture of Theories (1891)** The Doctrine of Necessity Examined (1892)** The Law of Mind (1892)** Man's Glassy Essence (1892)** Evolutionary Love (1893)* Immortality in the Light of Synechism (1893 MS)Peirce divided metaphysics into (1) ontology or general metaphysics, (2) psychical or religious metaphysics, and (3) physical metaphysics.==== Ontology ====On the issue of universals, Peirce was a scholastic realist, declaring the reality of generals as early as 1868.According to Peirce, his category he called \"thirdness\", the more general facts about the world, are extra-mental realities.", "Regarding modalities (possibility, necessity, etc.", "), he came in later years to regard himself as having wavered earlier as to just how positively real the modalities are.", "In his 1897 \"The Logic of Relatives\" he wrote:Peirce retained, as useful for some purposes, the definitions in terms of information states, but insisted that the pragmaticist is committed to a strong modal realism by conceiving of objects in terms of predictive general conditional propositions about how they ''would'' behave under certain circumstances.===== Continua =====Continuity and synechism are central in Peirce's philosophy: \"I did not at first suppose that it was, as I gradually came to find it, the master-Key of philosophy\".From a mathematical point of view, he embraced infinitesimals and worked long on the mathematics of continua.", "He long held that the real numbers constitute a pseudo-continuum; that a true continuum is the real subject matter of ''analysis situs'' (topology); and that a true continuum of instants exceeds—and within any lapse of time has room for—any Aleph number (any infinite ''multitude'' as he called it) of instants.In 1908 Peirce wrote that he found that a true continuum might have or lack such room.", "Jérôme Havenel (2008): \"It is on 26 May 1908, that Peirce finally gave up his idea that in every continuum there is room for whatever collection of any multitude.", "From now on, there are different kinds of continua, which have different properties.", "\"==== Psychical or religious metaphysics ====Peirce believed in God, and characterized such belief as founded in an instinct explorable in musing over the worlds of ideas, brute facts, and evolving habits—and it is a belief in God not as an ''actual'' or ''existent'' being (in Peirce's sense of those words), but all the same as a ''real'' being.", "In \"A Neglected Argument for the Reality of God\" (1908), Peirce sketches, for God's reality, an argument to a hypothesis of God as the Necessary Being, a hypothesis which he describes in terms of how it would tend to develop and become compelling in musement and inquiry by a normal person who is led, by the hypothesis, to consider as being purposed the features of the worlds of ideas, brute facts, and evolving habits (for example scientific progress), such that the thought of such purposefulness will \"stand or fall with the hypothesis\"; meanwhile, according to Peirce, the hypothesis, in supposing an \"infinitely incomprehensible\" being, starts off at odds with its own nature as a purportively true conception, and so, no matter how much the hypothesis grows, it both (A) inevitably regards itself as partly true, partly vague, and as continuing to define itself without limit, and (B) inevitably has God appearing likewise vague but growing, though God as the Necessary Being is not vague or growing; but the hypothesis will hold it to be ''more'' false to say the opposite, that God is purposeless.", "Peirce also argued that the will is free and (see Synechism) that there is at least an attenuated kind of immortality.==== Physical metaphysics ====Peirce held the view, which he called objective idealism, that \"matter is effete mind, inveterate habits becoming physical laws\".", "Peirce observed that \"Berkeley's metaphysical theories have at first sight an air of paradox and levity very unbecoming to a bishop\".", "Peirce asserted the reality of (1) absolute chance (his tychist view), (2) mechanical necessity (anancist view), and (3) that which he called the law of love (agapist view), echoing his categories Firstness, Secondness, and Thirdness, respectively.", "He held that fortuitous variation (which he also called \"sporting\"), mechanical necessity, and creative love are the three modes of evolution (modes called \"tychasm\", \"anancasm\", and \"agapasm\") of the cosmos and its parts.", "He found his conception of agapasm embodied in Lamarckian evolution; the overall idea in any case is that of evolution tending toward an end or goal, and it could also be the evolution of a mind or a society; it is the kind of evolution which manifests workings of mind in some general sense.", "He said that overall he was a synechist, holding with reality of continuity, especially of space, time, and law.=== Philosophy of science ===Peirce outlined two fields, \"Cenoscopy\" and \"Science of Review\", both of which he called philosophy.", "Both included philosophy about science.", "In 1903 he arranged them, from more to less theoretically basic, thus: # Science of Discovery.## Mathematics.## Cenoscopy (philosophy as discussed earlier in this article – categorial, normative, metaphysical), as First Philosophy, concerns positive phenomena in general, does not rely on findings from special sciences, and includes the ''general'' study of inquiry and scientific method.## Idioscopy, or the Special Sciences (of nature and mind).# Science of Review, as Ultimate Philosophy, arranges \"... the results of discovery, beginning with digests, and going on to endeavor to form a philosophy of science\".", "His examples included Humboldt's ''Cosmos'', Comte's ''Philosophie positive'', and Spencer's ''Synthetic Philosophy''.# Practical Science, or the Arts.Peirce placed, within Science of Review, the work and theory of classifying the sciences (including mathematics and philosophy).", "His classifications, on which he worked for many years, draw on argument and wide knowledge, and are of interest both as a map for navigating his philosophy and as an accomplished polymath's survey of research in his time.===Influence and legacy===Umberto Eco described Peirce as \"undoubtedly the greatest unpublished writer of our generation\" and by Karl Popper as \"one of the greatest philosophers of all time\".", "The Internet Encyclopedia of Philosophy says of Peirce that although \"long considered an eccentric figure whose contribution to pragmatism was to provide its name and whose importance was as an influence upon James and Dewey, Peirce’s significance in his own right is now largely accepted.\"" ], [ "See also", "* Howland will forgery trial* Hypostatic abstraction* * ''Laws of Form''* List of American philosophers* Logical machine* Logical matrix* Mathematical psychology* * Peircean realism* Pragmatics* * * Relation algebra* Truth table===Contemporaries associated with Peirce===* Oliver Wendell Holmes Jr.* George Herbert Mead" ], [ "Notes" ], [ "References" ], [ "External links", "* Arisbe: The Peirce Gateway , Joseph Ransdell, ed.", "Over 100 online writings by Peirce as of November 24, 2010, with annotations.", "Hundreds of online papers on Peirce.", "The peirce-l e-forum.", "Much else.", "* Center for Applied Semiotics (CAS) (1998–2003), Donald Cunningham & Jean Umiker-Sebeok, Indiana U.", "* and previously et al., Pontifical Catholic U. of (PUC-SP), Brazil.", "In Portuguese, some English.", "* Commens Digital Companion to C.S.", "Peirce, Mats Bergman, Sami Paavola, & , formerly Commens at Helsinki U.", "Includes Commens Dictionary of Peirce's Terms with Peirce's definitions, often many per term across the decades, and the Digital Encyclopedia of Charles S. Peirce (old edition still at old website).", "* Peirce , Carlo Sini, Rossella Fabbrichesi, et al., U. of Milan, Italy.", "In Italian and English.", "Part of Pragma.", "* Charles S. Peirce Foundation.", "Co-sponsoring the 2014 Peirce International Centennial Congress (100th anniversary of Peirce's death).", "* Charles S. Peirce Society'' Transactions of the Charles S. Peirce Society''.", "Quarterly journal of Peirce studies since spring 1965.Table of Contents of all issues.", "* Charles S. Peirce Studies, Brian Kariger, ed.", "* * Collegium for the Advanced Study of Picture Act and Embodiment: The Peirce Archive.", "Humboldt U, Berlin, Germany.", "Cataloguing Peirce's innumerable drawings & graphic materials.", "More info (Prof. Aud Sissel Hoel).", "* Digital Encyclopedia of Charles S. Peirce, ( now at UFJF) & Ricardo Gudwin ( at Unicamp), eds., Universidade Estadual de Campinas (Portuguese), Brazil, in English.", "84 authors listed, 51 papers online & more listed, as of January 31, 2009.Newer edition now at ''Commens Digital Companion to C.S.", "Peirce''.", "* Existential Graphs, Jay Zeman, ed., U. of Florida.", "Has 4 Peirce texts.", "* , ed., U. of Navarra, Spain.", "Big study site, Peirce & others in Spanish & English, bibliography, more.", "* Helsinki Peirce Research Center (HPRC), Ahti-Veikko Pietarinen et al., U. of Helsinki.", "* His Glassy Essence.", "Autobiographical Peirce.", "Kenneth Laine Ketner.", "* Institute for Studies in Pragmaticism, Kenneth Laine Ketner, Clyde Hendrick, et al., Texas Tech U. Peirce's life and works.", "* International Research Group on Abductive Inference, et al., eds., U., Frankfurt, Germany.", "Uses frames.", "Click on link at bottom of its home page for English.", "Moved to U. of Gießen, Germany, home page not in English but see Artikel section there.", "* L'I.R.S.C.E.", "(1974–2003) – , U. of , France.", "* Minute Semeiotic, , U. of , Brazil.", "English, Portuguese.", "* Peirce at ''Signo: Theoretical Semiotics on the Web'', Louis Hébert, director, supported by U. of Québec.", "Theory, application, exercises of Peirce's Semiotics and Esthetics.", "English, French.", "* Peirce Edition Project (PEP) , Indiana U.–Purdue U. Indianapolis (IUPUI).", "André De Tienne, Nathan Houser, et al.", "Editors of the ''Writings of Charles S. Peirce'' (W) and ''The Essential Peirce'' (EP) v. 2.Many study aids such as the Robin Catalog of Peirce's manuscripts & letters and:Biographical introductions to EP 1–2 and W 1–6 & 8 Most of ''Writings of Charles S. Peirce'', 2 readable online.", "PEP's branch at .", "Working on ''Writings of Charles S. Peirce'', 7: Peirce's work on the ''Century Dictionary''.", "Definition of the week.", "* Peirce's Existential Graphs, Frithjof Dau, Germany* Peirce Research Group, Department of Philosophy \"Piero Martinetti\" – University of Milan, Italy.", "* Pragmatism Cybrary, David Hildebrand & John Shook.", "* Research Group on Semiotic Epistemology and Mathematics Education (late 1990s), Germany).", "See ''Peirce Project Newsletter'' v. 3, n. 1, p.", "13.", "* Semiotics according to Robert Marty, with 76 definitions of the sign by C. S.", "Peirce.", "*" ] ]
wikipedia
[ [ "Carnot heat engine" ], [ "Introduction", "Axial cross section of Carnot's heat engine.", "In this diagram, ''abcd'' is a cylindrical vessel, ''cd'' is a movable piston, and ''A'' and ''B'' are constant–temperature bodies.", "The vessel may be placed in contact with either body or removed from both (as it is here).", "A '''Carnot heat engine''' is a theoretical heat engine that operates on the Carnot cycle.", "The basic model for this engine was developed by Nicolas Léonard Sadi Carnot in 1824.The Carnot engine model was graphically expanded by Benoît Paul Émile Clapeyron in 1834 and mathematically explored by Rudolf Clausius in 1857, work that led to the fundamental thermodynamic concept of entropy.", "The Carnot engine is the most efficient heat engine which is theoretically possible.", "The efficiency depends only upon the absolute temperatures of the hot and cold heat reservoirs between which it operates.A heat engine acts by transferring energy from a warm region to a cool region of space and, in the process, converting some of that energy to mechanical work.", "The cycle may also be reversed.", "The system may be worked upon by an external force, and in the process, it can transfer thermal energy from a cooler system to a warmer one, thereby acting as a refrigerator or heat pump rather than a heat engine.Every thermodynamic system exists in a particular state.", "A thermodynamic cycle occurs when a system is taken through a series of different states, and finally returned to its initial state.", "In the process of going through this cycle, the system may perform work on its surroundings, thereby acting as a heat engine.The Carnot engine is a theoretical construct, useful for exploring the efficiency limits of other heat engines.", "An actual Carnot engine, however, would be completely impractical to build." ], [ "Carnot's diagram", "In the adjacent diagram, from Carnot's 1824 work, ''Reflections on the Motive Power of Fire'', there are \"two bodies ''A'' and ''B'', kept each at a constant temperature, that of ''A'' being higher than that of ''B''.", "These two bodies to which we can give, or from which we can remove the heat without causing their temperatures to vary, exercise the functions of two unlimited reservoirs of caloric.", "We will call the first the furnace and the second the refrigerator.\"", "Carnot then explains how we can obtain motive power, i.e., \"work\", by carrying a certain quantity of heat from body ''A'' to body ''B''.It also acts as a cooler and hence can also act as a refrigerator." ], [ "Modern diagram", "Carnot engine diagram (modern) - where an amount of heat ''Q''H flows from a high temperature ''T''H furnace through the fluid of the \"working body\" (working substance) and the remaining heat ''Q''C flows into the cold sink ''T''C, thus forcing the working substance to do mechanical work ''W'' on the surroundings, via cycles of contractions and expansions.The previous image shows the original piston-and-cylinder diagram used by Carnot in discussing his ideal engine.", "The figure at right shows a block diagram of a generic heat engine, such as the Carnot engine.", "In the diagram, the \"working body\" (system), a term introduced by Clausius in 1850, can be any fluid or vapor body through which heat ''Q'' can be introduced or transmitted to produce work.", "Carnot had postulated that the fluid body could be any substance capable of expansion, such as vapor of water, vapor of alcohol, vapor of mercury, a permanent gas, air, etc.", "Although in those early years, engines came in a number of configurations, typically ''Q''H was supplied by a boiler, wherein water was boiled over a furnace; ''Q''C was typically removed by a stream of cold flowing water in the form of a condenser located on a separate part of the engine.", "The output work, ''W'', is transmitted by the movement of the piston as it is used to turn a crank-arm, which in turn was typically used to power a pulley so as to lift water out of flooded salt mines.", "Carnot defined work as \"weight lifted through a height\"." ], [ "Carnot cycle", "Figure 1: A Carnot cycle illustrated on a PV diagram to illustrate the work done.Figure 2: A Carnot cycle acting as a heat engine, illustrated on a temperature-entropy diagram.", "The cycle takes place between a hot reservoir at temperature and a cold reservoir at temperature .", "The vertical axis is temperature, the horizontal axis is entropy.The '''Carnot cycle''' when acting as a heat engine consists of the following steps:# '''Reversible isothermal expansion of the gas at the \"hot\" temperature, (isothermal heat addition or absorption).'''", "During this step ( to ) the gas is allowed to expand and it does work on the surroundings.", "The temperature of the gas (the system) does not change during the process, and thus the expansion is isothermic.", "The gas expansion is propelled by absorption of heat energy and of entropy from the high temperature reservoir.# '''Isentropic (reversible adiabatic) expansion of the gas (isentropic work output).'''", "For this step ( to ) the piston and cylinder are assumed to be thermally insulated, thus they neither gain nor lose heat.", "The gas continues to expand, doing work on the surroundings, and losing an equivalent amount of internal energy.", "The gas expansion causes it to cool to the \"cold\" temperature, .", "The entropy remains unchanged.# '''Reversible isothermal compression of the gas at the \"cold\" temperature, (isothermal heat rejection)''' ( to ).", "Now the gas is exposed to the cold temperature reservoir while the surroundings do work on the gas by compressing it (such as through the return compression of a piston), while causing an amount of waste heat (with the standard sign convention for heat) and of entropy to flow out of the gas to the low temperature reservoir.", "(In magnitude, this is the same amount of entropy absorbed in step 1.The entropy decreases in isothermal compression since the multiplicity of the system decreases with the volume.)", "In terms of magnitude, the recompression work performed by the surroundings in this step is less than the work performed on the surroundings in step 1 because it occurs at a lower pressure due to the lower temperature (i.e.", "the resistance to compression is lower under step 3 than the force of expansion under step 1).# '''Isentropic compression of the gas (isentropic work input)''' ( to ).", "Once again the piston and cylinder are assumed to be thermally insulated and the cold temperature reservoir is removed.", "During this step, the surroundings continue to do work to further compress the gas and both the temperature and pressure rise now that the heat sink has been removed.", "This additional work increases the internal energy of the gas, compressing it and causing the temperature to rise to .", "The entropy remains unchanged.", "At this point the gas is in the same state as at the start of step 1." ], [ "Carnot's theorem", "T–S diagram.", "For this figure, the curve indicates a vapor-liquid equilibrium (''See Rankine cycle'').", "Irreversible systems and losses of heat (for example, due to friction) prevent the ideal from taking place at every step.", "'''Carnot's theorem''' is a formal statement of this fact: ''No engine operating between two heat reservoirs can be more efficient than a Carnot engine operating between the same reservoirs.", "''===Explanation===This maximum efficiency is defined as above:* is the work done by the system (energy exiting the system as work),* is the heat put into the system (heat energy entering the system),* is the absolute temperature of the cold reservoir, and* is the absolute temperature of the hot reservoir.A corollary to Carnot's theorem states that: All reversible engines operating between the same heat reservoirs are equally efficient.It is easily shown that the efficiency is maximum when the entire cyclic process is a reversible process.", "This means the total entropy of system and surroundings (the entropies of the hot furnace, the \"working fluid\" of the heat engine, and the cold sink) remains constant when the \"working fluid\" completes one cycle and returns to its original state.", "(In the general and more realistic case of an irreversible process, the total entropy of this combined system would increase.", ")Since the \"working fluid\" comes back to the same state after one cycle, and entropy of the system is a state function, the change in entropy of the \"working fluid\" system is 0.Thus, it implies that the total entropy change of the furnace and sink is zero, for the process to be reversible and the efficiency of the engine to be maximum.", "This derivation is carried out in the next section.The coefficient of performance (COP) of the heat engine is the reciprocal of its efficiency." ], [ "Efficiency of real heat engines", "For a real heat engine, the total thermodynamic process is generally irreversible.", "The working fluid is brought back to its initial state after one cycle, and thus the change of entropy of the fluid system is 0, but the sum of the entropy changes in the hot and cold reservoir in this one cyclical process is greater than 0.The internal energy of the fluid is also a state variable, so its total change in one cycle is 0.So the total work done by the system is equal to the net heat put into the system, the sum of > 0 taken up and the waste heat < 0 given off:For real engines, stages 1 and 3 of the Carnot cycle, in which heat is absorbed by the \"working fluid\" from the hot reservoir, and released by it to the cold reservoir, respectively, no longer remain ideally reversible, and there is a temperature differential between the temperature of the reservoir and the temperature of the fluid while heat exchange takes place.During heat transfer from the hot reservoir at to the fluid, the fluid would have a slightly lower temperature than , and the process for the fluid may not necessarily remain isothermal.", "Let be the total entropy change of the fluid in the process of intake of heat.where the temperature of the fluid is always slightly lesser than , in this process.So, one would get:Similarly, at the time of heat injection from the fluid to the cold reservoir one would have, for the magnitude of total entropy change < 0 of the fluid in the process of expelling heat:where, during this process of transfer of heat to the cold reservoir, the temperature of the fluid is always slightly greater than .We have only considered the magnitude of the entropy change here.", "Since the total change of entropy of the fluid system for the cyclic process is 0, we must haveThe previous three equations, namely (3), (4), (5), substituted into (6) to give:For ΔSh ≥ (Qh/Th) +ΔSc ≥ (Qc/Tc) = 0ΔSh ≥ '''(Qh/Th)''' = - ΔSc ≥ (Qc/Tc)= -ΔSc ''≤'' '''(-Qc/Tc)'''it is at least '''(Qh/Th) ''≤'' (-Qc/Tc)'''Equations () and () combine to giveTo derive this step needs two adiabatic processes involved to show an isentropic process property for the ratio of the changing volumes of two isothermal processes are equal.", "Most importantly, since the two adiabatic processes are volume works without heat lost, and since the ratio of volume changes for this two processes are the same, so the works for these two adiabatic processes are the same with opposite direction to each other, namely, one direction is work done by the system and the other is work done on the system; therefore, heat efficiency only concerns the amount of work done by the heat absorbed comparing to the amount of heat absorbed by the system.Therefore, (W/Qh) = (Qh - Qc) / Qh= 1 - (Qc/Qh)= 1 - (Tc/Th)And, from (7)'''(Qh/Th) ''≤'' (-Qc/Tc)''' here Qc it is less than 0 (release heat) '''(Tc/Th) ''≤'' (-Qc/Qh)''''''-(Tc/Th) ≥ (Qc/Qh)''''''''1+''-(Tc/Th) ≥ ''1+''(Qc/Qh)''' 1 - (Tc/Th) '''≥ (Qh + Qc)/Qh''' here Qc<0, 1 - (Tc/Th) '''≥ (Qh - Qc)/Qh'''1 - (Tc/Th) '''≥ W/Qh'''Hence,where is the efficiency of the real engine, and is the efficiency of the Carnot engine working between the same two reservoirs at the temperatures and .", "For the Carnot engine, the entire process is 'reversible', and Equation () is an equality.", "Hence, the efficiency of the real engine is always less than the ideal Carnot engine.Equation () signifies that the total entropy of system and surroundings (the fluid and the two reservoirs) increases for the real engine, because (in a surroundings-based analysis) the entropy gain of the cold reservoir as flows into it at the fixed temperature , is greater than the entropy loss of the hot reservoir as leaves it at its fixed temperature .", "The inequality in Equation () is essentially the statement of the Clausius theorem.According to the second theorem, \"The efficiency of the Carnot engine is independent of the nature of the working substance\"." ], [ "The Carnot engine and Rudolf Diesel", "In 1892 Rudolf Diesel patented an internal combustion engine inspired by the Carnot engine.", "Diesel knew a Carnot engine is an ideal that cannot be built, but he thought he had invented a working approximation.", "His principle was unsound, but in his struggle to implement it he developed the practical engine that bears his name.The conceptual problem was how to achieve isothermal expansion in an internal combustion engine, since burning fuel at the highest temperature of the cycle would only raise the temperature further.", "Diesel's patented solution was: having achieved the highest temperature just by compressing the air, to add a small amount of fuel at a controlled rate, such that heating caused by burning the fuel would be counteracted by cooling caused by air expansion as the piston moved.", "Hence all the heat from the fuel would be transformed into work during the isothermal expansion, as required by Carnot's theorem.For the idea to work a small mass of fuel would have to be burnt in a huge mass of air.", "Diesel first proposed a working engine that would compress air to 250 atmospheres at , then cycle to one atmosphere at .", "However, this was well beyond the technological capabilities of the day, since it implied a compression ratio of 60:1.Such an engine, if it could have been built, would have had an efficiency of 73%.", "(In contrast, the best steam engines of his day achieved 7%.", ")Accordingly, Diesel sought to compromise.", "He calculated that, were he to reduce the peak pressure to a less ambitious 90 atmospheres, he would sacrifice only 5% of the thermal efficiency.", "Seeking financial support, he published the \"Theory and Construction of a Rational Heat Engine to Take the Place of the Steam Engine and All Presently Known Combustion Engines\" (1893).", "Endorsed by scientific opinion, including Lord Kelvin, he won the backing of Krupp and .", "He clung to the Carnot cycle as a symbol.", "But years of practical work failed to achieve an isothermal combustion engine, nor could have done, since it requires such an enormous quantity of air that it cannot develop enough power to compress it.", "Furthermore, controlled fuel injection turned out to be no easy matter.Even so, it slowly evolved over 25 years to become a practical high-compression air engine, its fuel injected near the end of the compression stroke and ignited by the heat of compression, the diesel engine.", "Today its efficiency is 40%." ], [ "Notes" ], [ "External links" ], [ "References", "** ( First Edition 1824) and ( Reissued Edition of 1878)* ( full text of 1897 ed.)", "( Archived HTML version)" ] ]
wikipedia
[ [ "Central America" ], [ "Introduction", "'''Central America''' is a subregion of the Americas.", "Its political boundaries are defined as bordering Mexico to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west.", "Central America is usually defined as consisting of seven countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama.", "Within Central America is the Mesoamerican biodiversity hotspot, which extends from northern Guatemala to central Panama.", "Due to the presence of several active geologic faults and the Central America Volcanic Arc, there is a high amount of seismic activity in the region, such as volcanic eruptions and earthquakes, which has resulted in death, injury, and property damage.In the pre-Columbian era, Central America was inhabited by the Indigenous peoples of Mesoamerica to the north and west and the Isthmo-Colombian peoples to the south and east.", "Following the Spanish expedition of Christopher Columbus' voyages to the Americas, Spain began to colonize the Americas.", "From 1609 to 1821, the majority of Central American territories (except for what would become Belize and Panama, and including the modern Mexican state of Chiapas) were governed by the viceroyalty of New Spain from Mexico City as the Captaincy General of Guatemala.", "On 24 August 1821, Spanish Viceroy Juan de O'Donojú signed the Treaty of Córdoba, which established New Spain's independence from Spain.", "On 15 September 1821, the Act of Independence of Central America was enacted to announce Central America's separation from the Spanish Empire and provide for the establishment of a new Central American state.", "Some of New Spain's provinces in the Central American region (i.e.", "what would become Guatemala, Honduras, El Salvador, Nicaragua and Costa Rica) were annexed to the First Mexican Empire; however in 1823 they seceded from Mexico to form the Federal Republic of Central America until 1838.In 1838, Costa Rica, Guatemala, Honduras, and Nicaragua became the first of Central America's seven states to become independent countries, followed by El Salvador in 1841, Panama in 1903, and Belize in 1981.Despite the dissolution of the Federal Republic of Central America, countries like Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua continue to maintain a Central American identity.", "The Belizeans are usually identified as culturally Caribbean rather than Central American, while the Panamanians identify themselves more broadly with their South American neighbors.The Spanish-speaking countries officially include both North America and South America as a single continent, , which is split into four subregions: North America (Northern America and Mexico), Central America, South America, and Insular America (the West Indies)." ], [ "Different definitions", "Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama are traditionally the seven Central American countries in political geography.", "\"Central America\" may mean different things to various people, based upon different contexts:* The non-official United Nations geoscheme for the Americas defines ''Central America'' as all states of mainland North America south of the United States, hence grouping Mexico as part of Central America for statistics purposes, but historically Mexico is considered North America.", "* Middle America is usually thought to comprise Mexico to the north of the 7 states of ''Central America'' as well as Colombia and Venezuela to the south.", "Usually, the whole of the Caribbean to the northeast, and sometimes the Guyanas, are also included.", "According to one source, the term \"Central America\" was used as a synonym for \"Middle America\" at least as recently as 1962.", "* In Ibero-America (Spanish and Portuguese speaking American countries), the Americas are considered a single continent (America), and Central America is considered a subregion of the continent comprising the seven countries south of Mexico and north of Colombia.", "* For the people living in the five countries, formerly part of the Federal Republic of Central America there is a distinction between the Spanish language terms \"América Central\" and \"Centroamérica\".", "While both can be translated into English as \"Central America\", \"América Central\" is generally used to refer to the geographical area of the seven countries between Mexico and Colombia, while \"Centroamérica\" is used when referring to the former members of the Federation emphasizing the shared culture and history of the region.", "* In Portuguese as a rule and occasionally in Spanish and other languages, the entirety of the Antilles is often included in the definition of Central America.", "Indeed, the Dominican Republic is a full member of the Central American Integration System." ], [ "History", "File:HuellasdeAcahualinca.jpg|Ancient footprints of Acahualinca, NicaraguaFile:Stone spheres of Costa Rica.", "Museo Nacional.jpg|Stone spheres of Costa RicaFile:Tazumal 10.jpg|Tazumal, El SalvadorFile:Tikal Temple1 2006 08 11.JPG|Tikal, GuatemalaFile:Copan HG-Treppe.jpg|Copan, HondurasFile:Altun Ha Belize.jpg|Altun Ha, BelizeCentral America, 1862Painting of the First Independence Movement celebration in San Salvador 1811Painting of the signing of the Declaration of Independence of Central America, Guatemala, 1821Central America was formed more than 3 million years ago, as part of the Isthmus of Panama, when its portion of land connected each side of water.In the Pre-Columbian era, the northern areas of Central America were inhabited by the indigenous peoples of Mesoamerica.", "Most notable among these were the Mayans, who had built numerous cities throughout the region, and the Aztecs, who had created a vast empire.", "The pre-Columbian cultures of eastern El Salvador, eastern Honduras, Caribbean Nicaragua, most of Costa Rica and Panama were predominantly speakers of the Chibchan languages at the time of European contact and are considered by some culturally different and grouped in the Isthmo-Colombian Area.Following the Spanish expedition of Christopher Columbus's voyages to the Americas, the Spanish sent many expeditions to the region, and they began their conquest of Maya territory in 1523.Soon after the conquest of the Aztec Empire, Spanish conquistador Pedro de Alvarado commenced the conquest of northern Central America for the Spanish Empire.", "Beginning with his arrival in Soconusco in 1523, Alvarado's forces systematically conquered and subjugated most of the major Maya kingdoms, including the K'iche', Tz'utujil, Pipil, and the Kaqchikel.", "By 1528, the conquest of Guatemala was nearly complete, with only the Petén Basin remaining outside the Spanish sphere of influence.", "The last independent Maya kingdoms – the Kowoj and the Itza people – were finally defeated in 1697, as part of the Spanish conquest of Petén.In 1538, Spain established the Real Audiencia of Panama, which had jurisdiction over all land from the Strait of Magellan to the Gulf of Fonseca.", "This entity was dissolved in 1543, and most of the territory within Central America then fell under the jurisdiction of the ''Audiencia Real de Guatemala''.", "This area included the current territories of Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and the Mexican state of Chiapas, but excluded the lands that would become Belize and Panama.", "The president of the Audiencia, which had its seat in Antigua Guatemala, was the governor of the entire area.", "In 1609 the area became a captaincy general and the governor was also granted the title of captain general.", "The Captaincy General of Guatemala encompassed most of Central America, with the exception of present-day Belize and Panama.The Captaincy General of Guatemala lasted for more than two centuries, but began to fray after a rebellion in 1811 which began in the Intendancy of San Salvador.", "The Captaincy General formally ended on 15 September 1821, with the signing of the Act of Independence of Central America.", "Mexican independence was achieved at virtually the same time with the signing of the Treaty of Córdoba and the Declaration of Independence of the Mexican Empire, and the entire region was finally independent from Spanish authority by 28 September 1821.===Historic flags of Central American Unions===File:Bandera de las Provincias Unidas del Centro de América.png|United Provinces of Central America (1823–1825)File:Bandera de Los Estados Unidos del Centro de América (1826).png|The United States of the Center of America (1826)File:Bandera República Federal de Centro América 1823 - 1841.jpg|Federal Republic of Central America (1827–1841)File:Republica Federal de Centro América 1842 -1845.jpg|Federal Republic of Central America (1842–1845)File:Central American Federation 1851.jpg|Central American Federation 1851–1853File:Flag of the Greater Republic of Central America 1896.jpg|Greater Republic of Central America (1896–1897)File:Flag of the Greater Republic of Central America (1898).svg|Greater Republic of Central America (1897–1898)File:Bandera de la República de Centro América 1921-1922.jpg|Republic of Central America (1921–1922)===Historic coat of arms of Central American Unions===File:Escudo de las Provincias Unidas del Centro de América.png|The United Provinces of Central America (1823–1825)File:Escudo de Los Estados Unidos del Centro de América (1826).png|United States of Central America (1826)File:Coat of Arms of the Federal Republic of Central America 1823 - 1841.jpg|Federal Republic of Central America (1827–1841)File:Escudo Republica Federal de Centro América 1842 -1845.jpg|Federal Republic of Central America (1842–1845) File:Central American Federation Coat of Arms 1851.jpg|Federation of Central America (1851–1853)File:The Greater Republic of Central America, 1896.jpg|The Greater Republic of Central America (1896–1897)File:Coat of arms of the Greater Republic of Central America (1898).svg|Greater Republic of Central America (1897–1898)File:Escudo República de Centro América 1921-1922.jpg|Republic of Central America (1921–1922)General Manuel José Arce; decorated Salvadoran General and president of the Federal Republic of Central America from 1825 to 1829The five rowed volcanos in the coat of arms of Central America was inspired by the Cordillera de Apaneca volcanic range of El Salvador, visible from the city of Sonsonate, which became the capital of the Federal Republic of Central America in 1834.Monument honoring the emblem of the United Provinces of Central AmericaThe historic military flag of the United Provinces of Central America with the national motto (God.", "Union.", "Liberty.)", "and the National Battalion initials (B.N.)", "in golden amber colorFrom its independence from Spain in 1821 until 1823, the former Captaincy General remained intact as part of the short-lived First Mexican Empire.", "When the Emperor of Mexico abdicated on 19 March 1823, Central America again became independent.", "On 1 July 1823, the Congress of Central America peacefully seceded from Mexico and declared absolute independence from all foreign nations, and the region formed the Federal Republic of Central America.The Federal Republic of Central America was a representative democracy with its capital at Guatemala City.", "This union consisted of the provinces of Costa Rica, El Salvador, Guatemala, Honduras, Los Altos, Mosquito Coast, and Nicaragua.", "The lowlands of southwest Chiapas, including Soconusco, initially belonged to the Republic until 1824, when Mexico annexed most of Chiapas and began its claims to Soconusco.", "The Republic lasted from 1823 to 1838, when it disintegrated as a result of civil wars.The territory that now makes up Belize was heavily contested in a dispute that continued for decades after Guatemala achieved independence.", "Spain, and later Guatemala, considered this land a Guatemalan department.", "In 1862, Britain formally declared it a British colony and named it British Honduras.", "It became independent as Belize in 1981.Panama, situated in the southernmost part of Central America on the Isthmus of Panama, has for most of its history been culturally and politically linked to South America.", "Panama was part of the Province of Tierra Firme from 1510 until 1538 when it came under the jurisdiction of the newly formed ''Audiencia Real de Panama''.", "Beginning in 1543, Panama was administered as part of the Viceroyalty of Peru, along with all other Spanish possessions in South America.", "Panama remained as part of the Viceroyalty of Peru until 1739, when it was transferred to the Viceroyalty of New Granada, the capital of which was located at Santa Fé de Bogotá.", "Panama remained as part of the Viceroyalty of New Granada until the disestablishment of that viceroyalty in 1819.A series of military and political struggles took place from that time until 1822, the result of which produced the republic of Gran Colombia.", "After the dissolution of Gran Colombia in 1830, Panama became part of a successor state, the Republic of New Granada.", "From 1855 until 1886, Panama existed as Panama State, first within the Republic of New Granada, then within the Granadine Confederation, and finally within the United States of Colombia.", "The United States of Colombia was replaced by the Republic of Colombia in 1886.As part of the Republic of Colombia, Panama State was abolished and it became the Isthmus Department.", "Despite the many political reorganizations, Colombia was still deeply plagued by conflict, which eventually led to the secession of Panama on 3 November 1903.Only after that time did some begin to regard Panama as a North or Central American entity.By the 1930s the United Fruit Company owned of land in Central America and the Caribbean and was the single largest land owner in Guatemala.", "Such holdings gave it great power over the governments of small countries.", "That was one of the factors that led to the coining of the phrase banana republic.After more than two hundred years of social unrest, violent conflict, and revolution, Central America today remains in a period of political transformation.", "Poverty, social injustice, and violence are still widespread.", "Nicaragua is the second poorest country in the western hemisphere (only Haiti is poorer).===Flags of modern Central America===File:Flag of Guatemala.svg|GuatemalaFile:Flag of El Salvador.svg|El SalvadorFile:Flag of Honduras.svg|HondurasFile:Flag of Nicaragua.svg|NicaraguaFile:Flag of Costa Rica.svg|Costa RicaFile:Flag of Panama.svg|PanamaFile:Flag of Belize.svg|Belize===Coat of arms of modern Central America===File:Coat of arms of Guatemala.svg|GuatemalaFile:Coat of arms of El Salvador.svg|El SalvadorFile:Coat of arms of Honduras.svg|HondurasFile:Coat of arms of Nicaragua.svg|NicaraguaFile:Coat of arms of Costa Rica.svg|Costa RicaFile:Coat of arms of Panama.svg|PanamaFile:Coat of arms of Belize.svg|Belize" ], [ "Geography", "The seven countries of Central America and their capitalsCentral America is a part of North America consisting of a tapering isthmus running from the southern extent of Mexico to the northwestern portion of South America.", "Central America has the Gulf of Mexico, a body of water within the Atlantic Ocean, to the north; the Caribbean Sea, also part of the Atlantic Ocean, to the northeast; and the Pacific Ocean to the southwest.", "Some physiographists define the Isthmus of Tehuantepec as the northern geographic border of Central America, while others use the northwestern borders of Belize and Guatemala.", "From there, the Central American land mass extends southeastward to the Atrato River, where it connects to the Pacific Lowlands in northwestern South America.Of the many mountain ranges within Central America, the longest are the Sierra Madre de Chiapas, the Cordillera Isabelia and the Cordillera de Talamanca.", "At , Volcán Tajumulco is the highest peak in Central America.", "Other high points of Central America are as listed in the table below:+High points in Central America Country Name Elevation RangeDoyle's DelightMaya MountainsCerro ChirripóCordillera de TalamancaCerro El PitalSierra Madre de ChiapasVolcán TajumulcoSierra Madre de ChiapasCerro Las MinasSierra Madre de ChiapasMogotónCordillera IsabeliaVolcán BarúCordillera de TalamancaCentral America geographyBetween the mountain ranges lie fertile valleys that are suitable for the raising of livestock and for the production of coffee, tobacco, beans and other crops.", "Most of the population of Honduras, Costa Rica and Guatemala lives in valleys.Trade winds have a significant effect upon the climate of Central America.", "Temperatures in Central America are highest just prior to the summer wet season, and are lowest during the winter dry season, when trade winds contribute to a cooler climate.", "The highest temperatures occur in April, due to higher levels of sunlight, lower cloud cover and a decrease in trade winds.=== Biodiversity ======Central American forests===File:Forest canopy in Belize (5344010084).jpg|Chiquibul Forest Reserve, BelizeFile:Zona de Acampar Parque Montecristo.jpg|Montecristo National Park, El SalvadorFile:Altagracia Volcan Maderas Bosque Nuboso.jpg|Maderas forest, NicaraguaFile:Small seepage pond near the top of Cerro El Chino - ZooKeys-298-077-g004B.jpg|Texiguat Wildlife Refuge HondurasFile:Monteverde bosque.jpg|Monteverde Cloud Forest Reserve, Costa Rica.File:DirkvdM cloudforest-jungle.jpg|Parque Internacional la Amistad, PanamaFile:Rain forest of Petén in Guatemala.jpg|Petén–Veracruz moist forests, GuatemalaEl Chorreron in El SalvadorCentral America is part of the Mesoamerican biodiversity hotspot, boasting 7% of the world's biodiversity.", "The Pacific Flyway is a major north–south flyway for migratory birds in the Americas, extending from Alaska to Tierra del Fuego.", "Due to the funnel-like shape of its land mass, migratory birds can be seen in very high concentrations in Central America, especially in the spring and autumn.", "As a bridge between North America and South America, Central America has many species from the Nearctic and the Neotropical realms.", "However the southern countries (Costa Rica and Panama) of the region have more biodiversity than the northern countries (Guatemala and Belize), meanwhile the central countries (Honduras, Nicaragua and El Salvador) have the least biodiversity.", "The table below shows recent statistics:+Biodiversity in Central America (numbers of different species of terrestrial vertebrate animals and vascular plants) Country Amphibian species Bird species Mammal species Reptile species Total terrestrial vertebrate species Vascular plants species BiodiversityBelize4654414714087728943771Costa Rica18383823225815111211913630El Salvador3043413710670729113618Guatemala133684193236124686819927Honduras101699201213121456806894Nicaragua61632181178105275908642Panama1829042412421569991511484Over 300 species of the region's flora and fauna are threatened, 107 of which are classified as critically endangered.", "The underlying problems are deforestation, which is estimated by FAO at 1.2% per year in Central America and Mexico combined, fragmentation of rainforests and the fact that 80% of the vegetation in Central America has already been converted to agriculture.Efforts to protect fauna and flora in the region are made by creating ecoregions and nature reserves.", "36% of Belize's land territory falls under some form of official protected status, giving Belize one of the most extensive systems of terrestrial protected areas in the Americas.", "In addition, 13% of Belize's marine territory are also protected.", "A large coral reef extends from Mexico to Honduras: the Mesoamerican Barrier Reef System.", "The Belize Barrier Reef is part of this.", "The Belize Barrier Reef is home to a large diversity of plants and animals, and is one of the most diverse ecosystems of the world.", "It is home to 70 hard coral species, 36 soft coral species, 500 species of fish and hundreds of invertebrate species.So far only about 10% of the species in the Belize barrier reef have been discovered.=== Flora ======National flowers of Central America===File:Lycaste virginalis forma Alba.jpg|''Lycaste skinneri'', GuatemalaFile:Yucca - ‘Daga española’ (7625319272).jpg|Izote flower, El SalvadorFile:Rhyncholaelia digbyana (16395522643).jpg|''Rhyncholaelia digbyana'', HondurasFile:Frangipani flower.jpg|''Plumeria'', NicaraguaFile:A and B Larsen orchids - Cattleya skinneri 574-24.jpg|''Guarianthe skinneri'', Costa RicaFile:Peristeria elata Orchi 11.jpg|''Peristeria elata'', PanamaFile:Encyclia cochleata - flower.jpg|''Prosthechea cochleata'', Belize===National trees of Central America===File:Enterolobium cyclocarpum in Guanacaste.jpg|''Enterolobium cyclocarpum'', Costa Rica File:Maquilishuat en flor.jpg|''Tabebuia rosea'', El Salvador File:Árbol Panamá - Sterculia apetala - Árbol Nacional de Panamá 01.JPG|''Sterculia apetala'', PanamaFile:Pinus oocarpa, San Rafael del Norte, Nicaragua.jpg|''Pinus oocarpa'', Honduras File:Calycophyllum candidissimum in Managua.jpg|''Calycophyllum candidissimum'', Nicaragua File:A big Mahogany tree.jpg|''Swietenia macrophylla'', Belize File:Ceiba, the Maya Tree of Life Laslovarga01.JPG|''Ceiba'', Guatemala One of the hanging bridges of the skywalk at the Monteverde Cloud Forest Reserve in Monteverde, Costa Rica disappearing into the cloudsFrom 2001 to 2010, of forest were lost in the region.", "In 2010 Belize had 63% of remaining forest cover, Costa Rica 46%, Panama 45%, Honduras 41%, Guatemala 37%, Nicaragua 29%, and El Salvador 21%.", "Most of the loss occurred in the moist forest biome, with .", "Woody vegetation loss was partially set off by a gain in the coniferous forest biome with , and a gain in the dry forest biome at .", "Mangroves and deserts contributed only 1% to the loss in forest vegetation.", "The bulk of the deforestation was located at the Caribbean slopes of Nicaragua with a loss of of forest in the period from 2001 to 2010.The most significant regrowth of of forest was seen in the coniferous woody vegetation of Honduras.===Montane forests===The Central American pine-oak forests ecoregion, in the tropical and subtropical coniferous forests biome, is found in Central America and southern Mexico.", "The Central American pine-oak forests occupy an area of , extending along the mountainous spine of Central America, extending from the Sierra Madre de Chiapas in Mexico's Chiapas state through the highlands of Guatemala, El Salvador, and Honduras to central Nicaragua.", "The pine-oak forests lie between elevation, and are surrounded at lower elevations by tropical moist forests and tropical dry forests.", "Higher elevations above are usually covered with Central American montane forests.", "The Central American pine-oak forests are composed of many species characteristic of temperate North America including oak, pine, fir, and cypress.Laurel forest is the most common type of Central American temperate evergreen cloud forest, found in almost all Central American countries, normally more than above sea level.", "Tree species include evergreen oaks, members of the laurel family, species of ''Weinmannia'' and ''Magnolia'', and ''Drimys granadensis''.", "The cloud forest of Sierra de las Minas, Guatemala, is the largest in Central America.", "In some areas of southeastern Honduras there are cloud forests, the largest located near the border with Nicaragua.", "In Nicaragua, cloud forests are situated near the border with Honduras, but many were cleared to grow coffee.", "There are still some temperate evergreen hills in the north.", "The only cloud forest in the Pacific coastal zone of Central America is on the Mombacho volcano in Nicaragua.", "In Costa Rica, there are laurel forests in the Cordillera de Tilarán and Volcán Arenal, called Monteverde, also in the Cordillera de Talamanca.The Central American montane forests are an ecoregion of the tropical and subtropical moist broadleaf forests biome, as defined by the World Wildlife Fund.", "These forests are of the moist deciduous and the semi-evergreen seasonal subtype of tropical and subtropical moist broadleaf forests and receive high overall rainfall with a warm summer wet season and a cooler winter dry season.", "Central American montane forests consist of forest patches located at altitudes ranging from , on the summits and slopes of the highest mountains in Central America ranging from Southern Mexico, through Guatemala, El Salvador, and Honduras, to northern Nicaragua.", "The entire ecoregion covers an area of and has a temperate climate with relatively high precipitation levels.=== Fauna ======Legendary National Birds of Central America===File:Male Resplendent Quetzal.jpg|Resplendent quetzal, GuatemalaFile:Eumomota superciliosa.jpg|Turquoise-browed motmot, El Salvador and NicaraguaFile:Keel-billed toucan.jpg|Keel-billed toucan, BelizeFile:Scarlet-Macaw.jpg|Scarlet macaw, HondurasFile:Turdus grayi 4zz.jpg|Clay-colored thrush, Costa RicaFile:Harpy Eagle.jpg|Harpy eagle, PanamaEcoregions are not only established to protect the forests themselves but also because they are habitats for an incomparably rich and often endemic fauna.", "Almost half of the bird population of the Talamancan montane forests in Costa Rica and Panama are endemic to this region.", "Several birds are listed as threatened, most notably the resplendent quetzal (Pharomacrus mocinno), three-wattled bellbird (Procnias tricarunculata), bare-necked umbrellabird (Cephalopterus glabricollis), and black guan (Chamaepetes unicolor).", "Many of the amphibians are endemic and depend on the existence of forest.", "The golden toad that once inhabited a small region in the Monteverde Reserve, which is part of the Talamancan montane forests, has not been seen alive since 1989 and is listed as extinct by IUCN.", "The exact causes for its extinction are unknown.", "Global warming may have played a role, because the development of that frog is typical for this area may have been compromised.", "Seven small mammals are endemic to the Costa Rica-Chiriqui highlands within the Talamancan montane forest region.", "Jaguars, cougars, spider monkeys, as well as tapirs, and anteaters live in the woods of Central America.", "The Central American red brocket is a brocket deer found in Central America's tropical forest.=== Geology ===Central America and the Caribbean PlateCentral America is geologically very active, with volcanic eruptions and earthquakes occurring frequently, and tsunamis occurring occasionally.", "Many thousands of people have died as a result of these natural disasters.Most of Central America rests atop the Caribbean Plate.", "This tectonic plate converges with the Cocos, Nazca, and North American plates to form the Middle America Trench, a major subduction zone.", "The Middle America Trench is situated some off the Pacific coast of Central America and runs roughly parallel to it.", "Many large earthquakes have occurred as a result of seismic activity at the Middle America Trench.", "For example, subduction of the Cocos Plate beneath the North American Plate at the Middle America Trench is believed to have caused the 1985 Mexico City earthquake that killed as many as 40,000 people.", "Seismic activity at the Middle America Trench is also responsible for earthquakes in 1902, 1942, 1956, 1982, 1992, January 2001, February 2001, 2007, 2012, 2014, and many other earthquakes throughout Central America.The Middle America Trench is not the only source of seismic activity in Central America.", "The Motagua Fault is an onshore continuation of the Cayman Trough which forms part of the tectonic boundary between the North American Plate and the Caribbean Plate.", "This transform fault cuts right across Guatemala and then continues offshore until it merges with the Middle America Trench along the Pacific coast of Mexico, near Acapulco.", "Seismic activity at the Motagua Fault has been responsible for earthquakes in 1717, 1773, 1902, 1976, 1980, and 2009.Another onshore continuation of the Cayman Trough is the Chixoy-Polochic Fault, which runs parallel to, and roughly to the north, of the Motagua Fault.", "Though less active than the Motagua Fault, seismic activity at the Chixoy-Polochic Fault is still thought to be capable of producing very large earthquakes, such as the 1816 earthquake of Guatemala.Managua, the capital of Nicaragua, was devastated by earthquakes in 1931 and 1972.Volcanic eruptions are also common in Central America.", "In 1968 the Arenal Volcano, in Costa Rica, erupted killing 87 people as the 3 villages of Tabacon, Pueblo Nuevo and San Luis were buried under pyroclastic flows and debris.", "Fertile soils from weathered volcanic lava have made it possible to sustain dense populations in the agriculturally productive highland areas." ], [ "Demographics", "===Life expectancy===List of countries by life expectancy at birth for 2021, according to the World Bank Group.", "List of Central American countries is expanded by Mexico and Colombia.Countries &territories2021Historical dataCOVID-19 impactAllMaleFemale200020142014→201920192019→202020202020→202120212014→2021 77.02 74.42 79.81 5.39 77.59 1.19 78.77 0.65 79.43 −0.15 79.28 −2.25 77.02 −2.40 −1.75 76.22 73.05 79.59 6.54 74.00 3.25 77.25 0.56 77.81 −1.15 76.66 −0.43 76.22 −1.59 −1.03 73.84 70.84 76.80 5.97 67.23 5.58 72.81 1.24 74.05 −2.26 71.80 2.04 73.84 −0.22 1.03 72.83 69.40 76.44 7.04 71.32 4.72 76.04 0.71 76.75 −1.98 74.77 −1.94 72.83 −3.92 −3.21 '''World''' '''71.33''' '''68.89''' '''73.95''' '''5.06''' '''67.70''' '''4.18''' '''71.88''' '''1.10''' '''72.98''' '''−0.74''' '''72.24''' '''−0.92''' '''71.33''' '''−1.65''' '''−0.55''' 70.75 66.08 75.15 9.07 69.86 1.88 71.75 0.81 72.56 −1.50 71.06 −0.31 70.75 −1.81 −1.00 70.47 67.12 74.33 7.21 68.56 4.75 73.31 0.62 73.93 −1.08 72.85 −2.38 70.47 −3.46 −2.84 70.21 66.06 74.86 8.81 73.57 1.23 74.80 −0.59 74.20 −4.07 70.13 0.08 70.21 −3.99 −4.58 70.12 67.89 72.53 4.64 68.66 3.60 72.26 0.62 72.88 −1.42 71.46 −1.34 70.12 −2.76 −2.14 69.24 66.00 72.65 6.65 67.45 4.52 71.96 1.17 73.13 −1.33 71.80 −2.56 69.24 −3.89 −2.73===Capital cities of Central America===File:Ciudad Cayala - Guatemala City.jpg|Guatemala CityFile:Panoramica del Centro Histórico de San Salvador.jpg|San SalvadorFile:Tegucigalpa view in october 2021.jpg|TegucigalpaFile:Panoramica De Managua.jpg|ManaguaFile:4- Vue San Jose.jpg|San Jose, Costa RicaFile:HDR of Panama City, Panama.jpg|Panama CityFile:Aerials Belize WHwy 02.jpg|BelmopanThe population of Central America is estimated at as of .", "With an area of , it has a population density of .", "Human Development Index values are from the estimates for 2017.+ Countries of Central America Country Area Population( est.)", "Populationdensity Capital Officiallanguage HumandevelopmentindexBelizeBelmopanEnglish0.708 '''High'''Costa RicaSan JoséSpanish0.794 '''High'''El SalvadorSan SalvadorSpanish0.674 '''Medium'''GuatemalaGuatemala CitySpanish0.650 '''Medium'''HondurasTegucigalpaSpanish0.617 '''Medium'''NicaraguaManaguaSpanish0.658 '''Medium'''PanamaPanama CitySpanish0.789 '''High''' Total0.699+ Largest metropolitan areas in Central America City Country Population Census Year % of NationalPopulationGuatemala CityGuatemala5,700,000201026%San SalvadorEl Salvador2,415,217200939%ManaguaNicaragua2,045,000201234%TegucigalpaHonduras1,819,000201024%San Pedro SulaHonduras1,600,000201021%+4Panama CityPanama1,400,000201037%San JoséCosta Rica1,275,000201330%=== Languages ===The official language majority in all Central American countries is Spanish, except in Belize, where the official language is English.", "Mayan languages constitute a language family consisting of about 26 related languages.", "Guatemala formally recognized 21 of these in 1996.Xinca, Miskito, and Garifuna are also present in Central America.+Languages in Central America (2010) RankCountry Population % Spanish% Mayanlanguages% English % Xinca % Garifuna1Guatemala17,284,00064.7%34.3%0.0%0.7%0.3%2Honduras8,447,00097.1%2.0%0.0%0.0%0.9%3El Salvador6,108,00099.0%1.0%0.0%0.0%0.0%4Nicaragua6,028,00087.4%7.1%5.5%0.0%0.0%5Costa Rica4,726,00097.2%1.8%1.0%0.0%0.0%6Panamá3,652,00086.8%0.0%4.0%0.0%0.0%7Belize408,86749.8%8.9%70.0%0.0%7.0%=== Ethnic groups ===Central America map of indigenous people before European contactCentral American womenThis region of the continent is very rich in terms of ethnic groups.", "The majority of the population is mestizo, with sizable Mayan and African descendent populations present, along with numerous other indigenous groups such as the Miskito people.", "The immigration of Arabs, Jews, Chinese, Europeans and others brought additional groups to the area.+Ethnic groups in Central America (2010)CountryPopulation% Amerindian% White% Mestizo/Mixed% Black% OtherBelize324,5286.3%5.0%49.6%32.0%4.1%Costa Rica4,301,7124.0%82.3%15.7%1.3%0.7%El Salvador6,340,8891.0%12.0%86.0%0.0%1.0%Guatemala15,700,00042.0%4.0%53.0%0.2%0.8%Honduras8,143,5646.0%5.5%82.0%6.0%0.5%Nicaragua5,815,5005.0%17.0%69.0%9.0%0.0%Panama3,474,5626.0%10.0%65.0%14.0%5.0%'''Total'''42,682,19010.04%17.04%59.77%9.77%2.91%=== Religious groups ======Cathedrals of Central America===File:CATEDRAL DE LA INMACULADA CONCEPCION, MANAGUA - panoramio.jpg|Immaculate Conception Cathedral, Managua Nicaragua File:Catedral Metropolitana de San Salvador.png|San Salvador Cathedral El Salvador File:CatedralGuatemala.jpg|Cathedral of Guatemala City GuatemalaFile:Metropolitan Cathedral in San Jose, Costa Rica.jpg|Metropolitan Cathedral of San José Costa Rica File:Iglesia Catedral de Panama.jpg|Metropolitan Cathedral of Panama City PanamaFile:CATEDRAL DE TEGUCIGALPA - panoramio.jpg|Tegucigalpa Cathedral Honduras File:HRrubenFromEast fixed.jpg|Holy Redeemer Cathedral Belize The predominant religion in Central America is Christianity (95.6%).", "Beginning with the Spanish colonization of Central America in the 16th century, Roman Catholicism became the most popular religion in the region until the first half of the 20th century.", "Since the 1960s, there has been an increase in other Christian groups, particularly Protestantism, as well as other religious organizations, and individuals identifying themselves as having no religion.+Proportions of the population by religion (2020)CountryRoman CatholicProtestantOther ChristianNon-AffiliatedOtherBelize47.4%34.5%7.1%6.8%3.2%Costa Rica72.5%19.5%2.4%4.5%1.1%El Salvador55.8%35.3%3.6%5.0%0.3%Guatemala55.4%25.9%14.3%4.0%0.4%Honduras64.9%29.1%2.2%3.1%0.7%Nicaragua58.3%36.7%1.4%3.4%0.1%Panama66.1%23.9%1.8%4.2%3.0%'''Source: Jason Mandrik, Operation World Statistics (2020).", "'''*Protestantism in Central America also include Independent Christian, most of total Protestants in this region (+80%) are Evangelicals, the rest follow traditional beliefs.", "*Other Christian include Other Traditional Churches (Orthodox, Episcopalian, etc.)", "and contemporary churches (Mormons, Adventists, Scientology, etc.", "), also include Non-denominational Christian who are the most numerous group, specially in Guatemala." ], [ "Culture", "===Central American art===File:JacaltecBrocade.jpg|Guatemalan textilesFile:KunaWomanWithMolas.jpg|Mola (art form), PanamaFile:Mercaditode Artesanias en el Centro Historico de Santa Ana.JPG|El Salvador La Plama art form===National dishes of Central America===File:Baleada.jpg|Baleada Honduras File:Pupusas El Salvador Centro America.JPG|Pupusa El Salvador File:SANCOCHO.jpg|Sancocho PanamaFile:Gallo Pinto at breakfast.jpg|Gallo pinto Costa Rica File:Nacatamal assembled.jpg|Nacatamal Nicaragua File:Rice and Beans, Stew Chicken and Potato Salad - Belize.jpg|Rice and beans BelizeFile:Cocinando El Pepian.jpg|Pepián Guatemala * Central American music* Central American cuisine* List of cuisines of the Americas – Central American cuisine=== Sport ===* Central American Games* Central American and Caribbean Games** 1926 Central American and Caribbean Games – the first time this event occurred* Central American Football Union* Surfing" ], [ "Politics", "===Leaders of Central America===File:Bernardo Arévalo, posesión 2024 (cropped).jpg|Bernardo Arévalo GuatemalaFile:Claudia Rodríguez de Guevara, Director of Municipal Works.png|Claudia Rodríguez de Guevara El Salvador File:Xiomara Castro 2022 (cropped).jpg|Xiomara Castro Honduras File:Daniel Ortega 2014 (cropped).jpg|Daniel Ortega NicaraguaFile:Rodrigo Chaves, discurso posesión (cropped).jpg|Rodrigo Chaves Robles Costa Rica File:Laurentino Cortizo at the Enthronement of Naruhito (1).jpg|Laurentino Cortizo PanamaFile:Johnny Briceño (52135383761) (cropped).jpg|Johnny Briceño Belize === Integration ===Central America is currently undergoing a process of political, economic and cultural transformation that started in 1907 with the creation of the Central American Court of Justice.In 1951 the integration process continued with the signature of the San Salvador Treaty, which created the ODECA, the Organization of Central American States.", "However, the unity of the ODECA was limited by conflicts between several member states.In 1991, the integration agenda was further advanced by the creation of the Central American Integration System (''Sistema para la Integración Centroamericana'', or SICA).", "SICA provides a clear legal basis to avoid disputes between the member states.", "SICA membership includes the 7 nations of Central America plus the Dominican Republic, a state that is traditionally considered part of the Caribbean.On 6 December 2008, SICA announced an agreement to pursue a common currency and common passport for the member nations.", "No timeline for implementation was discussed.Central America already has several supranational institutions such as the Central American Parliament, the Central American Bank for Economic Integration and the Central American Common Market.On 22 July 2011, President Mauricio Funes of El Salvador became the first president ''pro tempore'' to SICA.", "El Salvador also became the headquarters of SICA with the inauguration of a new building.=== Foreign relations ===Until recently, all Central American countries maintained diplomatic relations with Taiwan instead of China.", "President Óscar Arias of Costa Rica, however, established diplomatic relations with China in 2007, severing formal diplomatic ties with Taiwan.", "After breaking off relations with the Republic of China in 2017, Panama established diplomatic relations with the People's Republic of China.", "In August 2018, El Salvador also severed ties with Taiwan to formally start recognizing the People's Republic of China as sole China, a move many considered lacked transparency due to its abruptness and reports of the Chinese government's desires to invest in the department of La Union while also promising to fund the ruling party's reelection campaign.", "The President of El Salvador, Nayib Bukele, broke diplomatic relations with Taiwan and established ties with China.", "On 9 December 2021, Nicaragua resumed relations with the PRC.=== Parliament ===Emblem of the Central American ParliamentThe Central American Parliament (aka PARLACEN) is a political and parliamentary body of SICA.", "The parliament started around 1980, and its primary goal was to resolve conflicts in Nicaragua, Guatemala, and El Salvador.", "Although the group was disbanded in 1986, ideas of unity of Central Americans still remained, so a treaty was signed in 1987 to create the Central American Parliament and other political bodies.", "Its original members were Guatemala, El Salvador, Nicaragua and Honduras.", "The parliament is the political organ of Central America, and is part of SICA.", "New members have since then joined including Panama and the Dominican Republic.Costa Rica is not a member State of the Central American Parliament and its adhesion remains as a very unpopular topic at all levels of the Costa Rican society due to existing strong political criticism towards the regional parliament, since it is regarded by Costa Ricans as a menace to democratic accountability and effectiveness of integration efforts.", "Excessively high salaries for its members, legal immunity of jurisdiction from any member State, corruption, lack of a binding nature and effectiveness of the regional parliament's decisions, high operative costs and immediate membership of Central American Presidents once they leave their office and presidential terms, are the most common reasons invoked by Costa Ricans against the Central American Parliament." ], [ "Economy", "File:Banco deGuatemala.JPG|Central Bank of GuatemalaFile:World Trade Center San Salvador.jpg|World Trade Center San SalvadorFile:BCH.jpg|Central Bank of HondurasFile:Maqueta del Banco Central de Nicaragua.jpg|Central Bank of NicaraguaFile:Banco Central de Costa Rica.jpg|Central Bank of Costa RicaFile:Banco Nacional de Panamá, en vía España de la ciudad de Panamá.jpg|National Bank of PanamaFile:Belizean Central Bank 2015.jpg|Central Bank of Belize Federal Republic of Central America, 4 Escudos (1835).", "Struck in the San Jose, Costa Rica mint (697 were minted) Secretariat of Central American Economic IntegrationSigned in 2004, the Central American Free Trade Agreement (CAFTA) is an agreement between the United States, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and the Dominican Republic.", "The treaty is aimed at promoting free trade among its members.Guatemala has the largest economy in the region.", "Its main exports are coffee, sugar, bananas, petroleum, clothing, and cardamom.", "Of its 10.29 billion dollar annual exports, 40.2% go to the United States, 11.1% to neighboring El Salvador, 8% to Honduras, 5.5% to Mexico, 4.7% to Nicaragua, and 4.3% to Costa Rica.The region is particularly attractive for companies (especially clothing companies) because of its geographical proximity to the United States, very low wages and considerable tax advantages.", "In addition, the decline in the prices of coffee and other export products and the structural adjustment measures promoted by the international financial institutions have partly ruined agriculture, favouring the emergence of maquiladoras.", "This sector accounts for 42 per cent of total exports from El Salvador, 55 per cent from Guatemala, and 65 per cent from Honduras.", "However, its contribution to the economies of these countries is disputed; raw materials are imported, jobs are precarious and low-paid, and tax exemptions weaken public finances.They are also criticised for the working conditions of employees: insults and physical violence, abusive dismissals (especially of pregnant workers), working hours, non-payment of overtime.", "According to Lucrecia Bautista, coordinator of the ''maquilas'' sector of the audit firm Coverco, \"labour law regulations are regularly violated in maquilas and there is no political will to enforce their application.", "In the case of infringements, the labour inspectorate shows remarkable leniency.", "It is a question of not discouraging investors.\"", "Trade unionists are subject to pressure, and sometimes to kidnapping or murder.", "In some cases, business leaders have used the services of the maras.", "Finally, black lists containing the names of trade unionists or political activists are circulating in employers' circles.Economic growth in Central America is projected to slow slightly in 2014–15, as country-specific domestic factors offset the positive effects from stronger economic activity in the United States.+Gross Domestic Product (GDP) of Central American countriesCountryGDP(nominal)$ millionsGDP(nominalper capita)GDP(PPP)$ millionsBelize1,552$4,6022,914Costa Rica44,313 $10,43257,955El Salvador24,421 $3,87546,050Guatemala50,303 $3,51278,012Honduras18,320 $2,32337,408Nicaragua7,695 $1,83919,827Panama34,517 $10,83855,124=== Tourism ======Central American coast===File:Playa-blanca-885x500.jpg|Playa Blanca GuatemalaFile:Playa de Corral de Mulas, Usulután, El Salvador - panoramio.jpg|Jiquilisco Bay, El SalvadorFile:Roatan West End 95 we 006.jpg|Roatán, HondurasFile:Pink Pearl Island-5.jpg|Pink Pearl Island NicaraguaFile:Costa Rica Playa Tamarindo and Rivermouth 2007 Aerial Photograph Tamarindowiki 01.JPG|Tamarindo, Costa RicaFile:Insel Zapatilla Panama.jpg|Cayos Zapatilla, PanamaFile:Corozal Beach, Corozal, Belize.jpg|Corozal Beach, BelizeThe Great Blue Hole off the coast of Belize is a prime ecotourism destination.", "It is a UNESCO World Heritage SiteSemuc Champey, Guatemala.Tourism in Belize has grown considerably in more recent times, and it is now the second largest industry in the nation.", "Belizean Prime Minister Dean Barrow has stated his intention to use tourism to combat poverty throughout the country.", "The growth in tourism has positively affected the agricultural, commercial, and finance industries, as well as the construction industry.", "The results for Belize's tourism-driven economy have been significant, with the nation welcoming almost one million tourists in a calendar year for the first time in its history in 2012.Belize is also the only country in Central America with English as its official language, making this country a comfortable destination for English-speaking tourists.Costa Rica is the most visited nation in Central America.", "Tourism in Costa Rica is one of the fastest growing economic sectors of the country, having become the largest source of foreign revenue by 1995.Since 1999, tourism has earned more foreign exchange than bananas, pineapples and coffee exports combined.", "The tourism boom began in 1987, with the number of visitors up from 329,000 in 1988, through 1.03 million in 1999, to a historical record of 2.43 million foreign visitors and $1.92-billion in revenue in 2013.In 2012 tourism contributed with 12.5% of the country's GDP and it was responsible for 11.7% of direct and indirect employment.Tourism in Nicaragua has grown considerably recently, and it is now the second largest industry in the nation.", "Nicaraguan President Daniel Ortega has stated his intention to use tourism to combat poverty throughout the country.", "The growth in tourism has positively affected the agricultural, commercial, and finance industries, as well as the construction industry.", "The results for Nicaragua's tourism-driven economy have been significant, with the nation welcoming one million tourists in a calendar year for the first time in its history in 2010." ], [ "Transport", "=== Roads ===Central American license platesPan-American Highway slices through Central AmericaThe Inter-American Highway is the Central American section of the Pan-American Highway, and spans between Nuevo Laredo, Mexico, and Panama City, Panama.", "Because of the break in the highway known as the Darién Gap, it is not possible to cross between Central America and South America in an automobile.=== Waterways ====== Ports and harbors ====== Airports ====== Railways ===" ], [ "Education", "* List of architecture schools in Central America* List of universities in Belize* List of universities in Costa Rica* List of universities in El Salvador* List of universities in Guatemala* List of universities in Honduras* List of universities in Nicaragua* List of universities in Panama" ], [ "See also", "* Americas (terminology)* Central American Seaway* Index of Central America-related articles** Index of Belize-related articles** Index of Costa Rica-related articles** Index of El Salvador–related articles** Index of Guatemala-related articles** Index of Honduras-related articles** Index of Nicaragua-related articles** Index of Panama-related articles* List of largest cities in Central America** Cantons of Costa Rica** List of cities in Belize** List of cities in El Salvador** List of places in Guatemala** List of cities in Honduras** List of cities in Nicaragua** List of cities in Panama* West Indies" ], [ "Notes" ], [ "References" ], [ "Further reading", "* Berger, Mark T. ''Under northern eyes: Latin American studies and US hegemony in the Americas, 1898–1990.''", "(Indiana UP, 1995).", "* Biekart, Kees.", "\"Assessing the 'arrival of Democracy' in Central America.\"", "(2014): 117–126.online* Bowman, Kirk, Fabrice Lehoucq, and James Mahoney.", "\"Measuring political democracy: Case expertise, data adequacy, and Central America.\"", "''Comparative Political Studies'' 38.8 (2005): 939–970.online* Craig, Kern William.", "\"Public Policy in Central America: An Empirical Analysis.\"", "''Public Administration Research'' 2.2 (2013): 105+ online.", "* Dym, Jordana.", "''From sovereign villages to national states: city, state, and federation in Central America, 1759–1839'' (UNM Press, 2006).", "* von Feigenblatt, Otto Federico.", "\"Costa Rica's Neo-Realist Foreign Policy: Lifting the Veil Hiding the Discursive Co-Optation of Human Rights, Human Security, and Cosmopolitan Official Rhetoric.\"", "''International Journal of Arts & Sciences Conference,'' (2009).", "online* Krenn, Michael L. ''The Chains of Interdependence: US Policy Toward Central America, 1945–1954'' (ME Sharpe, 1996).", "* Kruijt, Dirk.", "''Guerrillas: war and peace in Central America'' (2013).", "* LaFeber, Walter.", "''Inevitable Revolutions: The United States in Central America'' (WW Norton & Company, 1993).", "* Leonard, Thomas M. \"Central America and the United States: Overlooked foreign policy objectives.\"", "''The Americas'' (1993): 1–30 online.", "* Oliva, Karen, and Chad Rector.", "\"Unbalanced Regional Political Integration Is Unstable: Evidence from the Federal Republic of Central America (1823–1838).\"", "Available at SSRN 2429123 (2014) online.", "* Pearcy, Thomas L. ''We answer only to God: Politics and the Military in Panama, 1903–1947'' (University of New Mexico Press, 1998).", "* Pérez, Orlando J.", "''Historical Dictionary of El Salvador'' (Rowman & Littlefield, 2016).", "* Perez-Brignoli, Hector.", "''A brief history of Central America'' (Univ of California Press, 1989).", "* Sola, Mauricio.", "''U.S.", "Intervention and Regime Change in Nicaragua'' (U of Nebraska Press, 2005).", "* Topik, Steven C., and Allen Wells, eds.", "''The second conquest of Latin America: coffee, henequen, and oil during the export boom, 1850–1930'' (U of Texas Press, 2010)." ], [ "External links", "* American Heritage Dictionaries, Central America (archived 14 March 2007)* Central America. ''", "Columbia Gazetteer of the World Online''.", "2006.New York: Columbia University Press.", "* Hernández, Consuelo (2009).", "Reconstruyendo a Centroamérica a través de la poesía.", "''Voces y perspectivas en la poesia latinoamericana del siglo XX''.", "Madrid: Visor.", "* Central America Video Links from the Dean Peter Krogh Foreign Affairs Digital Archives* Central America country pages* Teaching Central America" ] ]
wikipedia
[ [ "Continuous function" ], [ "Introduction", "In mathematics, a '''continuous function''' is a function such that a small variation of the argument induces a small variation of the value of the function.", "This implies there are no abrupt changes in value, known as ''discontinuities''.", "More precisely, a function is continuous if arbitrarily small changes in its value can be assured by restricting to sufficiently small changes of its argument.", "A '''discontinuous function''' is a function that is .", "Until the 19th century, mathematicians largely relied on intuitive notions of continuity and considered only continuous functions.", "The epsilon–delta definition of a limit was introduced to formalize the definition of continuity.Continuity is one of the core concepts of calculus and mathematical analysis, where arguments and values of functions are real and complex numbers.", "The concept has been generalized to functions between metric spaces and between topological spaces.", "The latter are the most general continuous functions, and their definition is the basis of topology.A stronger form of continuity is uniform continuity.", "In order theory, especially in domain theory, a related concept of continuity is Scott continuity.As an example, the function denoting the height of a growing flower at time would be considered continuous.", "In contrast, the function denoting the amount of money in a bank account at time would be considered discontinuous since it \"jumps\" at each point in time when money is deposited or withdrawn." ], [ "History", "A form of the epsilon–delta definition of continuity was first given by Bernard Bolzano in 1817.Augustin-Louis Cauchy defined continuity of as follows: an infinitely small increment of the independent variable ''x'' always produces an infinitely small change of the dependent variable ''y'' (see e.g.", "''Cours d'Analyse'', p. 34).", "Cauchy defined infinitely small quantities in terms of variable quantities, and his definition of continuity closely parallels the infinitesimal definition used today (see microcontinuity).", "The formal definition and the distinction between pointwise continuity and uniform continuity were first given by Bolzano in the 1830s, but the work wasn't published until the 1930s.", "Like Bolzano, Karl Weierstrass denied continuity of a function at a point ''c'' unless it was defined at and on both sides of ''c'', but Édouard Goursat allowed the function to be defined only at and on one side of ''c'', and Camille Jordan allowed it even if the function was defined only at ''c''.", "All three of those nonequivalent definitions of pointwise continuity are still in use.", "Eduard Heine provided the first published definition of uniform continuity in 1872, but based these ideas on lectures given by Peter Gustav Lejeune Dirichlet in 1854." ], [ "Real functions", "===Definition===The function is continuous on its domain (), but is discontinuous at when considered as a partial function defined on the reals..A real function that is a function from real numbers to real numbers can be represented by a graph in the Cartesian plane; such a function is continuous if, roughly speaking, the graph is a single unbroken curve whose domain is the entire real line.", "A more mathematically rigorous definition is given below.Continuity of real functions is usually defined in terms of limits.", "A function with variable is ''continuous at'' the real number , if the limit of as tends to , is equal to There are several different definitions of the (global) continuity of a function, which depend on the nature of its domain.", "A function is continuous on an open interval if the interval is contained in the function's domain and the function is continuous at every interval point.", "A function that is continuous on the interval (the whole real line) is often called simply a continuous function; one also says that such a function is ''continuous everywhere''.", "For example, all polynomial functions are continuous everywhere.A function is continuous on a semi-open or a closed interval; if the interval is contained in the domain of the function, the function is continuous at every interior point of the interval, and the value of the function at each endpoint that belongs to the interval is the limit of the values of the function when the variable tends to the endpoint from the interior of the interval.", "For example, the function is continuous on its whole domain, which is the closed interval Many commonly encountered functions are partial functions that have a domain formed by all real numbers, except some isolated points.", "Examples are the functions and When they are continuous on their domain, one says, in some contexts, that they are continuous, although they are not continuous everywhere.", "In other contexts, mainly when one is interested in their behavior near the exceptional points, one says they are discontinuous.A partial function is ''discontinuous'' at a point if the point belongs to the topological closure of its domain, and either the point does not belong to the domain of the function or the function is not continuous at the point.", "For example, the functions and are discontinuous at , and remain discontinuous whichever value is chosen for defining them at .", "A point where a function is discontinuous is called a ''discontinuity''.Using mathematical notation, several ways exist to define continuous functions in the three senses mentioned above.Let be a function defined on a subset of the set of real numbers.This subset is the domain of .", "Some possible choices include *: i.e., is the whole set of real numbers.", "or, for and real numbers,*: is a closed interval, or*: is an open interval.In the case of the domain being defined as an open interval, and do not belong to , and the values of and do not matter for continuity on .====Definition in terms of limits of functions====The function is ''continuous at some point'' of its domain if the limit of as ''x'' approaches ''c'' through the domain of ''f'', exists and is equal to In mathematical notation, this is written asIn detail this means three conditions: first, has to be defined at (guaranteed by the requirement that is in the domain of ).", "Second, the limit of that equation has to exist.", "Third, the value of this limit must equal (Here, we have assumed that the domain of ''f'' does not have any isolated points.", ")====Definition in terms of neighborhoods====A neighborhood of a point ''c'' is a set that contains, at least, all points within some fixed distance of ''c''.", "Intuitively, a function is continuous at a point ''c'' if the range of ''f'' over the neighborhood of ''c'' shrinks to a single point as the width of the neighborhood around ''c'' shrinks to zero.", "More precisely, a function ''f'' is continuous at a point ''c'' of its domain if, for any neighborhood there is a neighborhood in its domain such that whenever As neighborhoods are defined in any topological space, this definition of a continuous function applies not only for real functions but also when the domain and the codomain are topological spaces and is thus the most general definition.", "It follows that a function is automatically continuous at every isolated point of its domain.", "For example, every real-valued function on the integers is continuous.====Definition in terms of limits of sequences====The sequence converges to One can instead require that for any sequence of points in the domain which converges to ''c'', the corresponding sequence converges to In mathematical notation, ====Weierstrass and Jordan definitions (epsilon–delta) of continuous functions====Illustration of the --definition: at , any value satisfies the condition of the definition for .Explicitly including the definition of the limit of a function, we obtain a self-contained definition: Given a function as above and an element of the domain , is said to be continuous at the point when the following holds: For any positive real number however small, there exists some positive real number such that for all in the domain of with the value of satisfiesAlternatively written, continuity of at means that for every there exists a such that for all :More intuitively, we can say that if we want to get all the values to stay in some small neighborhood around we need to choose a small enough neighborhood for the values around If we can do that no matter how small the neighborhood is, then is continuous at In modern terms, this is generalized by the definition of continuity of a function with respect to a basis for the topology, here the metric topology.Weierstrass had required that the interval be entirely within the domain , but Jordan removed that restriction.====Definition in terms of control of the remainder====In proofs and numerical analysis, we often need to know how fast limits are converging, or in other words, control of the remainder.", "We can formalize this to a definition of continuity.", "A function is called a control function if* ''C'' is non-decreasing*A function is ''C''-continuous at if there exists such a neighbourhood that A function is continuous in if it is ''C''-continuous for some control function ''C''.This approach leads naturally to refining the notion of continuity by restricting the set of admissible control functions.", "For a given set of control functions a function is if it is for some For example, the Lipschitz and Hölder continuous functions of exponent below are defined by the set of control functions respectively ====Definition using oscillation====oscillation.Continuity can also be defined in terms of oscillation: a function ''f'' is continuous at a point if and only if its oscillation at that point is zero; in symbols, A benefit of this definition is that it discontinuity: the oscillation gives how the function is discontinuous at a point.This definition is helpful in descriptive set theory to study the set of discontinuities and continuous points – the continuous points are the intersection of the sets where the oscillation is less than (hence a set) – and gives a rapid proof of one direction of the Lebesgue integrability condition.The oscillation is equivalent to the definition by a simple re-arrangement and by using a limit (lim sup, lim inf) to define oscillation: if (at a given point) for a given there is no that satisfies the definition, then the oscillation is at least and conversely if for every there is a desired the oscillation is 0.The oscillation definition can be naturally generalized to maps from a topological space to a metric space.====Definition using the hyperreals====Cauchy defined the continuity of a function in the following intuitive terms: an infinitesimal change in the independent variable corresponds to an infinitesimal change of the dependent variable (see ''Cours d'analyse'', page 34).", "Non-standard analysis is a way of making this mathematically rigorous.", "The real line is augmented by adding infinite and infinitesimal numbers to form the hyperreal numbers.", "In nonstandard analysis, continuity can be defined as follows.", "(see microcontinuity).", "In other words, an infinitesimal increment of the independent variable always produces an infinitesimal change of the dependent variable, giving a modern expression to Augustin-Louis Cauchy's definition of continuity.===Construction of continuous functions===The graph of a cubic function has no jumps or holes.", "The function is continuous.Checking the continuity of a given function can be simplified by checking one of the above defining properties for the building blocks of the given function.", "It is straightforward to show that the sum of two functions, continuous on some domain, is also continuous on this domain.", "Giventhen the (defined by for all ) is continuous in The same holds for the ,(defined by for all )is continuous in Combining the above preservations of continuity and the continuity of constant functions and of the identity function one arrives at the continuity of all polynomial functions such as(pictured on the right).The graph of a continuous rational function.", "The function is not defined for The vertical and horizontal lines are asymptotes.In the same way, it can be shown that the (defined by for all such that )is continuous in This implies that, excluding the roots of the (defined by for all , such that )is also continuous on .For example, the function (pictured)is defined for all real numbers and is continuous at every such point.", "Thus, it is a continuous function.", "The question of continuity at does not arise since is not in the domain of There is no continuous function that agrees with for all The sinc and the cos functionsSince the function sine is continuous on all reals, the sinc function is defined and continuous for all real However, unlike the previous example, ''G'' be extended to a continuous function on real numbers, by the value to be 1, which is the limit of when ''x'' approaches 0, i.e.,Thus, by setting:the sinc-function becomes a continuous function on all real numbers.", "The term is used in such cases when (re)defining values of a function to coincide with the appropriate limits make a function continuous at specific points.A more involved construction of continuous functions is the function composition.", "Given two continuous functions their composition, denoted as and defined by is continuous.This construction allows stating, for example, that is continuous for all ===Examples of discontinuous functions===section 2.1.3).An example of a discontinuous function is the Heaviside step function , defined byPick for instance .", "Then there is no around , i.e.", "no open interval with that will force all the values to be within the of , i.e.", "within .", "Intuitively, we can think of this type of discontinuity as a sudden jump in function values.Similarly, the signum or sign functionis discontinuous at but continuous everywhere else.", "Yet another example: the functionis continuous everywhere apart from .Point plot of Thomae's function on the interval (0,1).", "The topmost point in the middle shows f(1/2) = 1/2.Besides plausible continuities and discontinuities like above, there are also functions with a behavior, often coined pathological, for example, Thomae's function,is continuous at all irrational numbers and discontinuous at all rational numbers.", "In a similar vein, Dirichlet's function, the indicator function for the set of rational numbers,is nowhere continuous.===Properties=======A useful lemma====Let be a function that is continuous at a point and be a value such Then throughout some neighbourhood of ''Proof:'' By the definition of continuity, take , then there exists such that Suppose there is a point in the neighbourhood for which then we have the contradiction====Intermediate value theorem====The intermediate value theorem is an existence theorem, based on the real number property of completeness, and states::If the real-valued function ''f'' is continuous on the closed interval and ''k'' is some number between and then there is some number such that For example, if a child grows from 1 m to 1.5 m between the ages of two and six years, then, at some time between two and six years of age, the child's height must have been 1.25 m.As a consequence, if ''f'' is continuous on and and differ in sign, then, at some point must equal zero.====Extreme value theorem====The extreme value theorem states that if a function ''f'' is defined on a closed interval (or any closed and bounded set) and is continuous there, then the function attains its maximum, i.e.", "there exists with for all The same is true of the minimum of ''f''.", "These statements are not, in general, true if the function is defined on an open interval (or any set that is not both closed and bounded), as, for example, the continuous function defined on the open interval (0,1), does not attain a maximum, being unbounded above.====Relation to differentiability and integrability====Every differentiable functionis continuous, as can be shown.", "The converse does not hold: for example, the absolute value function:is everywhere continuous.", "However, it is not differentiable at (but is so everywhere else).", "Weierstrass's function is also everywhere continuous but nowhere differentiable.The derivative ''f′''(''x'') of a differentiable function ''f''(''x'') need not be continuous.", "If ''f′''(''x'') is continuous, ''f''(''x'') is said to be ''continuously differentiable''.", "The set of such functions is denoted More generally, the set of functions(from an open interval (or open subset of ) to the reals) such that ''f'' is times differentiable and such that the -th derivative of ''f'' is continuous is denoted See differentiability class.", "In the field of computer graphics, properties related (but not identical) to are sometimes called (continuity of position), (continuity of tangency), and (continuity of curvature); see Smoothness of curves and surfaces.Every continuous functionis integrable (for example in the sense of the Riemann integral).", "The converse does not hold, as the (integrable but discontinuous) sign function shows.====Pointwise and uniform limits====thumbGiven a sequenceof functions such that the limitexists for all , the resulting function is referred to as the pointwise limit of the sequence of functions The pointwise limit function need not be continuous, even if all functions are continuous, as the animation at the right shows.", "However, ''f'' is continuous if all functions are continuous and the sequence converges uniformly, by the uniform convergence theorem.", "This theorem can be used to show that the exponential functions, logarithms, square root function, and trigonometric functions are continuous.===Directional and semi-continuity===Image:Right-continuous.svg|A right-continuous functionImage:Left-continuous.svg|A left-continuous functionDiscontinuous functions may be discontinuous in a restricted way, giving rise to the concept of directional continuity (or right and left continuous functions) and semi-continuity.", "Roughly speaking, a function is if no jump occurs when the limit point is approached from the right.", "Formally, ''f'' is said to be right-continuous at the point ''c'' if the following holds: For any number however small, there exists some number such that for all ''x'' in the domain with the value of will satisfyThis is the same condition as continuous functions, except it is required to hold for ''x'' strictly larger than ''c'' only.", "Requiring it instead for all ''x'' with yields the notion of functions.", "A function is continuous if and only if it is both right-continuous and left-continuous.A function ''f'' is if, roughly, any jumps that might occur only go down, but not up.", "That is, for any there exists some number such that for all ''x'' in the domain with the value of satisfiesThe reverse condition is .==Continuous functions between metric spaces== The concept of continuous real-valued functions can be generalized to functions between metric spaces.", "A metric space is a set equipped with a function (called metric) that can be thought of as a measurement of the distance of any two elements in ''X''.", "Formally, the metric is a functionthat satisfies a number of requirements, notably the triangle inequality.", "Given two metric spaces and and a functionthen is continuous at the point (with respect to the given metrics) if for any positive real number there exists a positive real number such that all satisfying will also satisfy As in the case of real functions above, this is equivalent to the condition that for every sequence in with limit we have The latter condition can be weakened as follows: is continuous at the point if and only if for every convergent sequence in with limit , the sequence is a Cauchy sequence, and is in the domain of .The set of points at which a function between metric spaces is continuous is a set – this follows from the definition of continuity.This notion of continuity is applied, for example, in functional analysis.", "A key statement in this area says that a linear operatorbetween normed vector spaces and (which are vector spaces equipped with a compatible norm, denoted ) is continuous if and only if it is bounded, that is, there is a constant such thatfor all ===Uniform, Hölder and Lipschitz continuity===For a Lipschitz continuous function, there is a double cone (shown in white) whose vertex can be translated along the graph so that the graph always remains entirely outside the cone.The concept of continuity for functions between metric spaces can be strengthened in various ways by limiting the way depends on and ''c'' in the definition above.", "Intuitively, a function ''f'' as above is uniformly continuous if the doesnot depend on the point ''c''.", "More precisely, it is required that for every real number there exists such that for every with we have that Thus, any uniformly continuous function is continuous.", "The converse does not generally hold but holds when the domain space ''X'' is compact.", "Uniformly continuous maps can be defined in the more general situation of uniform spaces.A function is Hölder continuous with exponent α (a real number) if there is a constant ''K'' such that for all the inequalityholds.", "Any Hölder continuous function is uniformly continuous.", "The particular case is referred to as Lipschitz continuity.", "That is, a function is Lipschitz continuous if there is a constant ''K'' such that the inequalityholds for any The Lipschitz condition occurs, for example, in the Picard–Lindelöf theorem concerning the solutions of ordinary differential equations." ], [ "{{anchor|Continuous map (topology)}}Continuous functions between topological spaces", "Another, more abstract, notion of continuity is the continuity of functions between topological spaces in which there generally is no formal notion of distance, as there is in the case of metric spaces.", "A topological space is a set ''X'' together with a topology on ''X'', which is a set of subsets of ''X'' satisfying a few requirements with respect to their unions and intersections that generalize the properties of the open balls in metric spaces while still allowing one to talk about the neighborhoods of a given point.", "The elements of a topology are called open subsets of ''X'' (with respect to the topology).A functionbetween two topological spaces ''X'' and ''Y'' is continuous if for every open set the inverse imageis an open subset of ''X''.", "That is, ''f'' is a function between the sets ''X'' and ''Y'' (not on the elements of the topology ), but the continuity of ''f'' depends on the topologies used on ''X'' and ''Y''.This is equivalent to the condition that the preimages of the closed sets (which are the complements of the open subsets) in ''Y'' are closed in ''X''.An extreme example: if a set ''X'' is given the discrete topology (in which every subset is open), all functionsto any topological space ''T'' are continuous.", "On the other hand, if ''X'' is equipped with the indiscrete topology (in which the only open subsets are the empty set and ''X'') and the space ''T'' set is at least T0, then the only continuous functions are the constant functions.", "Conversely, any function whose codomain is indiscrete is continuous.=== Continuity at a point ===Continuity at a point: For every neighborhood ''V'' of , there is a neighborhood ''U'' of ''x'' such that The translation in the language of neighborhoods of the -definition of continuity leads to the following definition of the continuity at a point:This definition is equivalent to the same statement with neighborhoods restricted to open neighborhoods and can be restated in several ways by using preimages rather than images.Also, as every set that contains a neighborhood is also a neighborhood, and is the largest subset of such that this definition may be simplified into:As an open set is a set that is a neighborhood of all its points, a function is continuous at every point of if and only if it is a continuous function.If ''X'' and ''Y'' are metric spaces, it is equivalent to consider the neighborhood system of open balls centered at ''x'' and ''f''(''x'') instead of all neighborhoods.", "This gives back the above definition of continuity in the context of metric spaces.", "In general topological spaces, there is no notion of nearness or distance.", "If, however, the target space is a Hausdorff space, it is still true that ''f'' is continuous at ''a'' if and only if the limit of ''f'' as ''x'' approaches ''a'' is ''f''(''a'').", "At an isolated point, every function is continuous.Given a map is continuous at if and only if whenever is a filter on that converges to in which is expressed by writing then necessarily in If denotes the neighborhood filter at then is continuous at if and only if in Moreover, this happens if and only if the prefilter is a filter base for the neighborhood filter of in === Alternative definitions ===Several equivalent definitions for a topological structure exist; thus, several equivalent ways exist to define a continuous function.==== Sequences and nets ====In several contexts, the topology of a space is conveniently specified in terms of limit points.", "This is often accomplished by specifying when a point is the limit of a sequence.", "Still, for some spaces that are too large in some sense, one specifies also when a point is the limit of more general sets of points indexed by a directed set, known as nets.", "A function is (Heine-)continuous only if it takes limits of sequences to limits of sequences.", "In the former case, preservation of limits is also sufficient; in the latter, a function may preserve all limits of sequences yet still fail to be continuous, and preservation of nets is a necessary and sufficient condition.In detail, a function is '''sequentially continuous''' if whenever a sequence in converges to a limit the sequence converges to Thus, sequentially continuous functions \"preserve sequential limits.\"", "Every continuous function is sequentially continuous.", "If is a first-countable space and countable choice holds, then the converse also holds: any function preserving sequential limits is continuous.", "In particular, if is a metric space, sequential continuity and continuity are equivalent.", "For non-first-countable spaces, sequential continuity might be strictly weaker than continuity.", "(The spaces for which the two properties are equivalent are called sequential spaces.)", "This motivates the consideration of nets instead of sequences in general topological spaces.", "Continuous functions preserve the limits of nets, and this property characterizes continuous functions.For instance, consider the case of real-valued functions of one real variable:''Proof.''", "Assume that is continuous at (in the sense of continuity).", "Let be a sequence converging at (such a sequence always exists, for example, ); since is continuous at For any such we can find a natural number such that for all since converges at ; combining this with we obtainAssume on the contrary that is sequentially continuous and proceed by contradiction: suppose is not continuous at then we can take and call the corresponding point : in this way we have defined a sequence such thatby construction but , which contradicts the hypothesis of sequentially continuity.", "==== Closure operator and interior operator definitions ====In terms of the interior operator, a function between topological spaces is continuous if and only if for every subset In terms of the closure operator, is continuous if and only if for every subset That is to say, given any element that belongs to the closure of a subset necessarily belongs to the closure of in If we declare that a point is a subset if then this terminology allows for a plain English description of continuity: is continuous if and only if for every subset maps points that are close to to points that are close to Similarly, is continuous at a fixed given point if and only if whenever is close to a subset then is close to Instead of specifying topological spaces by their open subsets, any topology on can alternatively be determined by a closure operator or by an interior operator.", "Specifically, the map that sends a subset of a topological space to its topological closure satisfies the Kuratowski closure axioms.", "Conversely, for any closure operator there exists a unique topology on (specifically, ) such that for every subset is equal to the topological closure of in If the sets and are each associated with closure operators (both denoted by ) then a map is continuous if and only if for every subset Similarly, the map that sends a subset of to its topological interior defines an interior operator.", "Conversely, any interior operator induces a unique topology on (specifically, ) such that for every is equal to the topological interior of in If the sets and are each associated with interior operators (both denoted by ) then a map is continuous if and only if for every subset ==== Filters and prefilters ====Continuity can also be characterized in terms of filters.", "A function is continuous if and only if whenever a filter on converges in to a point then the prefilter converges in to This characterization remains true if the word \"filter\" is replaced by \"prefilter.", "\"===Properties===If and are continuous, then so is the composition If is continuous and* ''X'' is compact, then ''f''(''X'') is compact.", "* ''X'' is connected, then ''f''(''X'') is connected.", "* ''X'' is path-connected, then ''f''(''X'') is path-connected.", "* ''X'' is Lindelöf, then ''f''(''X'') is Lindelöf.", "* ''X'' is separable, then ''f''(''X'') is separable.The possible topologies on a fixed set ''X'' are partially ordered: a topology is said to be coarser than another topology (notation: ) if every open subset with respect to is also open with respect to Then, the identity mapis continuous if and only if (see also comparison of topologies).", "More generally, a continuous functionstays continuous if the topology is replaced by a coarser topology and/or is replaced by a finer topology.===Homeomorphisms===Symmetric to the concept of a continuous map is an open map, for which of open sets are open.", "If an open map ''f'' has an inverse function, that inverse is continuous, and if a continuous map ''g'' has an inverse, that inverse is open.", "Given a bijective function ''f'' between two topological spaces, the inverse function need not be continuous.", "A bijective continuous function with a continuous inverse function is called a .If a continuous bijection has as its domain a compact space and its codomain is Hausdorff, then it is a homeomorphism.===Defining topologies via continuous functions===Given a functionwhere ''X'' is a topological space and ''S'' is a set (without a specified topology), the final topology on ''S'' is defined by letting the open sets of ''S'' be those subsets ''A'' of ''S'' for which is open in ''X''.", "If ''S'' has an existing topology, ''f'' is continuous with respect to this topology if and only if the existing topology is coarser than the final topology on ''S''.", "Thus, the final topology is the finest topology on ''S'' that makes ''f'' continuous.", "If ''f'' is surjective, this topology is canonically identified with the quotient topology under the equivalence relation defined by ''f''.Dually, for a function ''f'' from a set ''S'' to a topological space ''X'', the initial topology on ''S'' is defined by designating as an open set every subset ''A'' of ''S'' such that for some open subset ''U'' of ''X''.", "If ''S'' has an existing topology, ''f'' is continuous with respect to this topology if and only if the existing topology is finer than the initial topology on ''S''.", "Thus, the initial topology is the coarsest topology on ''S'' that makes ''f'' continuous.", "If ''f'' is injective, this topology is canonically identified with the subspace topology of ''S'', viewed as a subset of ''X''.A topology on a set ''S'' is uniquely determined by the class of all continuous functions into all topological spaces ''X''.", "Dually, a similar idea can be applied to maps" ], [ "Related notions", "If is a continuous function from some subset of a topological space then a of to is any continuous function such that for every which is a condition that often written as In words, it is any continuous function that restricts to on This notion is used, for example, in the Tietze extension theorem and the Hahn–Banach theorem.", "If is not continuous, then it could not possibly have a continuous extension.", "If is a Hausdorff space and is a dense subset of then a continuous extension of to if one exists, will be unique.", "The Blumberg theorem states that if is an arbitrary function then there exists a dense subset of such that the restriction is continuous; in other words, every function can be restricted to some dense subset on which it is continuous.", "Various other mathematical domains use the concept of continuity in different but related meanings.", "For example, in order theory, an order-preserving function between particular types of partially ordered sets and is continuous if for each directed subset of we have Here is the supremum with respect to the orderings in and respectively.", "This notion of continuity is the same as topological continuity when the partially ordered sets are given the Scott topology.In category theory, a functorbetween two categories is called if it commutes with small limits.", "That is to say,for any small (that is, indexed by a set as opposed to a class) diagram of objects in .A is a generalization of metric spaces and posets, which uses the concept of quantales, and that can be used to unify the notions of metric spaces and domains." ], [ "See also", "* Continuity (mathematics)* Absolute continuity* Dini continuity* Equicontinuity* Geometric continuity* Parametric continuity* Classification of discontinuities* Coarse function* Continuous function (set theory)* Continuous stochastic process* Normal function* Open and closed maps* Piecewise* Symmetrically continuous function* Direction-preserving function - an analog of a continuous function in discrete spaces." ], [ "References" ], [ "Bibliography", "* *" ] ]
wikipedia
[ [ "Curl (mathematics)" ], [ "Introduction", "Depiction of a two-dimensional vector field with a uniform curl.In vector calculus, the '''curl''', also known as '''rotor''', is a vector operator that describes the infinitesimal circulation of a vector field in three-dimensional Euclidean space.", "The curl at a point in the field is represented by a vector whose length and direction denote the magnitude and axis of the maximum circulation.", "The curl of a field is formally defined as the circulation density at each point of the field.A vector field whose curl is zero is called irrotational.", "The curl is a form of differentiation for vector fields.", "The corresponding form of the fundamental theorem of calculus is Stokes' theorem, which relates the surface integral of the curl of a vector field to the line integral of the vector field around the boundary curve.The notation is more common in North America.", "In the rest of the world, particularly in 20th century scientific literature, the alternative notation is traditionally used, which comes from the \"rate of rotation\" that it represents.", "To avoid confusion, modern authors tend to use the cross product notation with the del (nabla) operator, as in which also reveals the relation between curl (rotor), divergence, and gradient operators.Unlike the gradient and divergence, curl as formulated in vector calculus does not generalize simply to other dimensions; some generalizations are possible, but only in three dimensions is the geometrically defined curl of a vector field again a vector field.", "This deficiency is a direct consequence of the limitations of vector calculus; on the other hand, when expressed as an antisymmetric tensor field via the wedge operator of geometric calculus, the curl generalizes to all dimensions.", "The circumstance is similar to that attending the 3-dimensional cross product, and indeed the connection is reflected in the notation for the curl.", "The name \"curl\" was first suggested by James Clerk Maxwell in 1871 but the concept was apparently first used in the construction of an optical field theory by James MacCullagh in 1839." ], [ "Definition", "The curl of a vector field , denoted by , or , or , is an operator that maps functions in to functions in , and in particular, it maps continuously differentiable functions to continuous functions .", "It can be defined in several ways, to be mentioned below:One way to define the curl of a vector field at a point is implicitly through its projections onto various axes passing through the point: if is any unit vector, the projection of the curl of onto may be defined to be the limiting value of a closed line integral in a plane orthogonal to divided by the area enclosed, as the path of integration is contracted indefinitely around the point.More specifically, the curl is defined at a point aswhere the line integral is calculated along the boundary of the area in question, being the magnitude of the area.", "This equation defines the projection of the curl of onto .", "The infinitesimal surfaces bounded by have as their normal.", "is oriented via the right-hand rule.The above formula means that the projection of the curl of a vector field along a certain axis is the ''infinitesimal area density'' of the circulation of the field projected onto a plane perpendicular to that axis.", "This formula does not ''a priori'' define a legitimate vector field, for the individual circulation densities with respect to various axes ''a priori'' need not relate to each other in the same way as the components of a vector do; that they ''do'' indeed relate to each other in this precise manner must be proven separately.To this definition fits naturally the Kelvin–Stokes theorem, as a global formula corresponding to the definition.", "It equates the surface integral of the curl of a vector field to the above line integral taken around the boundary of the surface.Another way one can define the curl vector of a function at a point is explicitly as the limiting value of a vector-valued surface integral around a shell enclosing divided by the volume enclosed, as the shell is contracted indefinitely around .More specifically, the curl may be defined by the vector formulawhere the surface integral is calculated along the boundary of the volume , being the magnitude of the volume, and pointing outward from the surface perpendicularly at every point in .In this formula, the cross product in the integrand measures the tangential component of at each point on the surface , together with the orientation of these tangential components with respect to the surface .", "Thus, the surface integral measures the overall extent to which circulates around , together with the net orientation of this circulation in space.", "The ''curl'' of a vector field at a point is then the ''infinitesimal volume density'' of the net ''vector'' circulation (i.e., both magnitude and spatial orientation) of the field around the point.To this definition fits naturally another global formula (similar to the Kelvin-Stokes theorem) which equates the volume integral of the curl of a vector field to the above surface integral taken over the boundary of the volume.", "Whereas the above two definitions of the curl are coordinate free, there is another \"easy to memorize\" definition of the curl in curvilinear orthogonal coordinates, e.g.", "in Cartesian coordinates, spherical, cylindrical, or even elliptical or parabolic coordinates: The equation for each component can be obtained by exchanging each occurrence of a subscript 1, 2, 3 in cyclic permutation: 1 → 2, 2 → 3, and 3 → 1 (where the subscripts represent the relevant indices).If are the Cartesian coordinates and are the orthogonal coordinates, then is the length of the coordinate vector corresponding to .", "The remaining two components of curl result from cyclic permutation of indices: 3,1,2 → 1,2,3 → 2,3,1." ], [ "Usage", "In practice, the two coordinate-free definitions described above are rarely used because in virtually all cases, the curl operator can be applied using some set of curvilinear coordinates, for which simpler representations have been derived.The notation has its origins in the similarities to the 3-dimensional cross product, and it is useful as a mnemonic in Cartesian coordinates if is taken as a vector differential operator del.", "Such notation involving operators is common in physics and algebra.Expanded in 3-dimensional Cartesian coordinates (see ''Del in cylindrical and spherical coordinates'' for spherical and cylindrical coordinate representations), is, for composed of (where the subscripts indicate the components of the vector, not partial derivatives):where , , and are the unit vectors for the -, -, and -axes, respectively.", "This expands as follows:Although expressed in terms of coordinates, the result is invariant under proper rotations of the coordinate axes but the result inverts under reflection.In a general coordinate system, the curl is given bywhere denotes the Levi-Civita tensor, the covariant derivative, is the determinant of the metric tensor and the Einstein summation convention implies that repeated indices are summed over.", "Due to the symmetry of the Christoffel symbols participating in the covariant derivative, this expression reduces to the partial derivative:where are the local basis vectors.", "Equivalently, using the exterior derivative, the curl can be expressed as:Here and are the musical isomorphisms, and is the Hodge star operator.", "This formula shows how to calculate the curl of in any coordinate system, and how to extend the curl to any oriented three-dimensional Riemannian manifold.", "Since this depends on a choice of orientation, curl is a chiral operation.", "In other words, if the orientation is reversed, then the direction of the curl is also reversed." ], [ "Examples", "=== Example 0 ===Suppose the vector field describes the velocity field of a fluid flow (such as a large tank of liquid or gas) and a small ball is located within the fluid or gas (the center of the ball being fixed at a certain point).", "If the ball has a rough surface, the fluid flowing past it will make it rotate.", "The rotation axis (oriented according to the right hand rule) points in the direction of the curl of the field at the center of the ball, and the angular speed of the rotation is half the magnitude of the curl at this point.The curl of the vector field at any point is given by the rotation of an infinitesimal area in the ''xy''-plane (for ''z''-axis component of the curl), ''zx''-plane (for ''y''-axis component of the curl) and ''yz''-plane (for ''x''-axis component of the curl vector).", "This can be seen in the examples below.=== Example 1 ===The vector fieldcan be decomposed asUpon visual inspection, the field can be described as \"rotating\".", "If the vectors of the field were to represent a linear force acting on objects present at that point, and an object were to be placed inside the field, the object would start to rotate clockwise around itself.", "This is true regardless of where the object is placed.Calculating the curl:The resulting vector field describing the curl would at all points be pointing in the negative direction.", "The results of this equation align with what could have been predicted using the right-hand rule using a right-handed coordinate system.", "Being a uniform vector field, the object described before would have the same rotational intensity regardless of where it was placed.=== Example 2 ===For the vector fieldthe curl is not as obvious from the graph.", "However, taking the object in the previous example, and placing it anywhere on the line , the force exerted on the right side would be slightly greater than the force exerted on the left, causing it to rotate clockwise.", "Using the right-hand rule, it can be predicted that the resulting curl would be straight in the negative direction.", "Inversely, if placed on , the object would rotate counterclockwise and the right-hand rule would result in a positive direction.Calculating the curl:The curl points in the negative direction when is positive and vice versa.", "In this field, the intensity of rotation would be greater as the object moves away from the plane .===Further examples===* In a vector field describing the linear velocities of each part of a rotating disk in uniform circular motion, the curl has the same value at all points, and this value turns out to be exactly two times the vectorial angular velocity of the disk (oriented as usual by the right-hand rule).", "More generally, for any flowing mass, the linear velocity vector field at each point of the mass flow has a curl (the vorticity of the flow at that point) equal to exactly two times the ''local'' vectorial angular velocity of the mass about the point.", "* For any solid object subject to an external physical force (such as gravity or the electromagnetic force), one may consider the vector field representing the infinitesimal force-per-unit-volume contributions acting at each of the points of the object.", "This force field may create a net ''torque'' on the object about its center of mass, and this torque turns out to be directly proportional and vectorially parallel to the (vector-valued) integral of the ''curl'' of the force field over the whole volume.", "* Of the four Maxwell's equations, two—Faraday's law and Ampère's law—can be compactly expressed using curl.", "Faraday's law states that the curl of an electric field is equal to the opposite of the time rate of change of the magnetic field, while Ampère's law relates the curl of the magnetic field to the current and the time rate of change of the electric field." ], [ "Identities", "In general curvilinear coordinates (not only in Cartesian coordinates), the curl of a cross product of vector fields and can be shown to beInterchanging the vector field and operator, we arrive at the cross product of a vector field with curl of a vector field:where is the Feynman subscript notation, which considers only the variation due to the vector field (i.e., in this case, is treated as being constant in space).Another example is the curl of a curl of a vector field.", "It can be shown that in general coordinatesand this identity defines the vector Laplacian of , symbolized as .The curl of the gradient of ''any'' scalar field is always the zero vector fieldwhich follows from the antisymmetry in the definition of the curl, and the symmetry of second derivatives.The divergence of the curl of any vector field is equal to zero: If is a scalar valued function and is a vector field, then" ], [ "Generalizations", "The vector calculus operations of grad, curl, and div are most easily generalized in the context of differential forms, which involves a number of steps.", "In short, they correspond to the derivatives of 0-forms, 1-forms, and 2-forms, respectively.", "The geometric interpretation of curl as rotation corresponds to identifying bivectors (2-vectors) in 3 dimensions with the special orthogonal Lie algebra of infinitesimal rotations (in coordinates, skew-symmetric 3 × 3 matrices), while representing rotations by vectors corresponds to identifying 1-vectors (equivalently, 2-vectors) and these all being 3-dimensional spaces.=== Differential forms ===In 3 dimensions, a differential 0-form is a real-valued function ; a differential 1-form is the following expression, where the coefficients are functions:a differential 2-form is the formal sum, again with function coefficients:and a differential 3-form is defined by a single term with one function as coefficient:(Here the -coefficients are real functions of three variables; the \"wedge products\", e.g.", ", can be interpreted as some kind of oriented area elements, , etc.", ")The exterior derivative of a -form in is defined as the -form from above—and in if, e.g.,then the exterior derivative leads toThe exterior derivative of a 1-form is therefore a 2-form, and that of a 2-form is a 3-form.", "On the other hand, because of the interchangeability of mixed derivatives, and antisymmetry,the twofold application of the exterior derivative yields (the zero -form).Thus, denoting the space of -forms by and the exterior derivative by one gets a sequence:Here is the space of sections of the exterior algebra vector bundle over '''R'''''n'', whose dimension is the binomial coefficient ; note that for or .", "Writing only dimensions, one obtains a row of Pascal's triangle:the 1-dimensional fibers correspond to scalar fields, and the 3-dimensional fibers to vector fields, as described below.", "Modulo suitable identifications, the three nontrivial occurrences of the exterior derivative correspond to grad, curl, and div.Differential forms and the differential can be defined on any Euclidean space, or indeed any manifold, without any notion of a Riemannian metric.", "On a Riemannian manifold, or more generally pseudo-Riemannian manifold, -forms can be identified with -vector fields (-forms are -covector fields, and a pseudo-Riemannian metric gives an isomorphism between vectors and covectors), and on an ''oriented'' vector space with a nondegenerate form (an isomorphism between vectors and covectors), there is an isomorphism between -vectors and -vectors; in particular on (the tangent space of) an oriented pseudo-Riemannian manifold.", "Thus on an oriented pseudo-Riemannian manifold, one can interchange -forms, -vector fields, -forms, and -vector fields; this is known as Hodge duality.", "Concretely, on this is given by:* 1-forms and 1-vector fields: the 1-form corresponds to the vector field .", "* 1-forms and 2-forms: one replaces by the dual quantity (i.e., omit ), and likewise, taking care of orientation: corresponds to , and corresponds to .", "Thus the form corresponds to the \"dual form\" .Thus, identifying 0-forms and 3-forms with scalar fields, and 1-forms and 2-forms with vector fields:* grad takes a scalar field (0-form) to a vector field (1-form);* curl takes a vector field (1-form) to a pseudovector field (2-form);* div takes a pseudovector field (2-form) to a pseudoscalar field (3-form)On the other hand, the fact that corresponds to the identitiesfor any scalar field , andfor any vector field .Grad and div generalize to all oriented pseudo-Riemannian manifolds, with the same geometric interpretation, because the spaces of 0-forms and -forms at each point are always 1-dimensional and can be identified with scalar fields, while the spaces of 1-forms and -forms are always fiberwise -dimensional and can be identified with vector fields.Curl does not generalize in this way to 4 or more dimensions (or down to 2 or fewer dimensions); in 4 dimensions the dimensions areso the curl of a 1-vector field (fiberwise 4-dimensional) is a ''2-vector field'', which at each point belongs to 6-dimensional vector space, and so one haswhich yields a sum of six independent terms, and cannot be identified with a 1-vector field.", "Nor can one meaningfully go from a 1-vector field to a 2-vector field to a 3-vector field (4 → 6 → 4), as taking the differential twice yields zero ().", "Thus there is no curl function from vector fields to vector fields in other dimensions arising in this way.However, one can define a curl of a vector field as a ''2-vector field'' in general, as described below.=== Curl geometrically ===2-vectors correspond to the exterior power ; in the presence of an inner product, in coordinates these are the skew-symmetric matrices, which are geometrically considered as the special orthogonal Lie algebra of infinitesimal rotations.", "This has dimensions, and allows one to interpret the differential of a 1-vector field as its infinitesimal rotations.", "Only in 3 dimensions (or trivially in 0 dimensions) we have , which is the most elegant and common case.", "In 2 dimensions the curl of a vector field is not a vector field but a function, as 2-dimensional rotations are given by an angle (a scalar – an orientation is required to choose whether one counts clockwise or counterclockwise rotations as positive); this is not the div, but is rather perpendicular to it.", "In 3 dimensions the curl of a vector field is a vector field as is familiar (in 1 and 0 dimensions the curl of a vector field is 0, because there are no non-trivial 2-vectors), while in 4 dimensions the curl of a vector field is, geometrically, at each point an element of the 6-dimensional Lie algebra The curl of a 3-dimensional vector field which only depends on 2 coordinates (say and ) is simply a vertical vector field (in the direction) whose magnitude is the curl of the 2-dimensional vector field, as in the examples on this page.Considering curl as a 2-vector field (an antisymmetric 2-tensor) has been used to generalize vector calculus and associated physics to higher dimensions." ], [ "Inverse", "In the case where the divergence of a vector field is zero, a vector field exists such that .", "This is why the magnetic field, characterized by zero divergence, can be expressed as the curl of a magnetic vector potential.If is a vector field with , then adding any gradient vector field to will result in another vector field such that as well.", "This can be summarized by saying that the inverse curl of a three-dimensional vector field can be obtained up to an unknown irrotational field with the Biot–Savart law." ], [ "See also", "*Helmholtz decomposition*Del in cylindrical and spherical coordinates*Vorticity" ], [ "References" ], [ "Further reading", "* *" ], [ "External links", "* * *" ] ]
wikipedia
[ [ "Carl Friedrich Gauss" ], [ "Introduction", "'''Johann Carl Friedrich Gauss''' ( ; ; 30 April 177723 February 1855) was a German mathematician, geodesist, and physicist who made significant contributions to many fields in mathematics and science.", "Gauss ranks among history's most influential mathematicians and has been referred to as the \"Prince of Mathematicians\".", "He was director of the Göttingen Observatory and professor at the university for nearly half a century, from 1807 until his death in 1855.While still a student at the University of Göttingen, he propounded several mathematical theorems.", "Gauss completed his masterpieces ''Disquisitiones Arithmeticae'' and ''Theoria motus corporum coelestium'' as a private scholar.", "He published the second and third complete proofs of the fundamental theorem of algebra, made contributions to number theory, developed the theories of binary and ternary quadratic forms, and is credited with inventing the fast Fourier transform algorithm.", "He is considered one of the discoverers of non-Euclidean geometry alongside Nikolai Lobachevsky and János Bolyai and coined that term.Gauss was instrumental in the discovery of the dwarf planet Ceres.", "His work on the motion of planetoids disturbed by large planets led to the introduction of the Gaussian gravitational constant and the method of least squares, which he discovered before Adrien-Marie Legendre published on the method.Gauss was in charge of the extensive geodetic survey of the Kingdom of Hanover together with an arc measurement project from 1820 to 1844, did much of the fieldwork, and provided the complete scientific evaluation.Gauss is one of the founders of geophysics while formulating the fundamental principles of magnetism, and did basic practical research in this field.Gauss invented the heliotrope in 1821, a magnetometer in 1833 and, alongside Wilhelm Eduard Weber, the first electromagnetic telegraph in 1833.Gauss was a careful author and refused to publish incomplete work.", "Although he published extensively during his life, he left behind several works to be published posthumously.", "He believed that the act of learning, not possession of knowledge, provided the greatest enjoyment.", "Although Gauss was known to dislike teaching, some of his students became influential mathematicians." ], [ "Biography", "=== Youth and education ===House of birth in Brunswick (destroyed in World War II)Caricature of Abraham Gotthelf Kästner by Gauss (1795)Johann Carl Friedrich Gauss was born on 30 April 1777 in Brunswick (Braunschweig), in the Duchy of Brunswick-Wolfenbüttel (now part of Lower Saxony, Germany), to a family of lower social status.", "His father Gebhard Dietrich Gauss (1744–1808) worked in several jobs, as butcher, bricklayer, gardener, and as treasurer of a death-benefit fund.", "Gauss characterized his father as an honourable and respected man, but rough and dominating at home.", "He was experienced in writing and calculating, but his wife Dorothea (1743–1839), Carl Friedrich's mother, was nearly illiterate.", "Carl Friedrich was christened and confirmed in a church near the school that he attended as a child.", "He had one elder brother from his father's first marriage.Gauss was a child prodigy in the field of mathematics.", "When the elementary teachers noticed his intellectual abilities, they brought him to the attention of the Duke of Brunswick, who sent him to the local ''Collegium Carolinum'', which he attended from 1792 to 1795 with Eberhard August Wilhelm von Zimmermann as one of his teachers.", "Thereafter the Duke granted him the resources for studies of mathematics, sciences, and classical languages at the Hanoverian University of Göttingen until 1798.It is not known why Gauss went to Göttingen and not to the University of Helmstedt near his native Brunswick, but it is assumed that the large library of Göttingen, where students were allowed to borrow books and take them home, was the decisive reason.", "One of his professors in mathematics was Abraham Gotthelf Kästner, whom Gauss called \"the leading mathematician among poets, and the leading poet among mathematicians\" because of his epigrams.", "Gauss depicted him in a drawing showing a lecture scene where he produced errors in a simple calculation.", "Astronomy was taught by Karl Felix von Seyffer (1762–1822), with whom Gauss stayed in correspondence after graduation; Olbers and Gauss mocked him in their correspondence.", "On the other hand, he thought highly of Georg Christoph Lichtenberg, his teacher of physics, and of Christian Gottlob Heyne, whose lectures in classics Gauss attended with pleasure.", "Fellow students of this time were Johann Friedrich Benzenberg, Farkas Bolyai, and Heinrich Wilhelm Brandes.Though being a registered student at university, it is evident that he was a self-taught student in mathematics, since he independently rediscovered several theorems.", "He succeeded with a breakthrough in a geometrical problem that had occupied mathematicians since the days of the Ancient Greeks when he determined in 1796 which regular polygons can be constructed by compass and straightedge.", "This discovery was the subject of his first publication and ultimately led Gauss to choose mathematics instead of philology as a career.", "Gauss' mathematical diary shows that, in the same year, he was also productive in number theory.", "He made advanced discoveries in modular arithmetic, found the first proof of the quadratic reciprocity law, and dealt with the prime number theorem.", "Many ideas for his mathematical magnum opus ''Disquisitiones arithmeticae'', published in 1801, date from this time.=== Private scholar ===Gauss graduated as a Doctor of Philosophy in 1799.He did not graduate from Göttingen, as is sometimes stated, but rather, at the Duke of Brunswick's special request, from the University of Helmstedt, the only state university of the duchy.", "There, Johann Friedrich Pfaff assessed his doctoral thesis, and Gauss got the degree ''in absentia'' without the further oral examination that was usually requested.", "The Duke then granted him his cost of living as a private scholar in Brunswick.", "Gauss showed his gratitude and loyalty for this bequest when he refused several calls from the Russian Academy of Sciences in St. Peterburg and from Landshut University.", "Later, the Duke promised him the foundation of an observatory in Brunswick in 1804.Architect Peter Joseph Krahe made preliminary designs, but one of Napoleon's wars cancelled those plans: the Duke was mortally wounded in the battle of Jena in 1806.The duchy was abolished in the following year, and Gauss's financial support stopped.", "He then followed a call to the University of Göttingen, an institution of the newly founded Kingdom of Westphalia under Jérôme Bonaparte, as full professor and director of the astronomical observatory.Studying the calculation of asteroid orbits, Gauss established contact with the astronomical community of Bremen and Lilienthal, especially Wilhelm Olbers, Karl Ludwig Harding and Friedrich Wilhelm Bessel, as part of the informal group of astronomers known as the Celestial police.", "One of their aims was the discovery of further planets, and they assembled data on asteroids and comets as a basis for Gauss's research.", "Gauss was thereby able to develop new, powerful methods for the determination of orbits, which he later published in his astronomical magnum opus ''Theoria motus corporum coelestium'' (1809).=== Professor in Göttingen ===Old Göttingen observatory, circa 1800Gauss on his deathbed (1855)Gauss arrived at Göttingen in November 1807, and in the following years he was confronted with the demand for two thousand francs from the Westphalian government as a war contribution.", "Without having yet received his salary, he could not raise this enormous amount.", "Both Olbers and Laplace wanted to help him with the payment, but Gauss refused their assistance.", "Finally, an anonymous person from Frankfurt, later discovered to be Prince-primate Dalberg, paid the sum.Gauss took on the directorate of the 60-year-old observatory, founded in 1748 by Prince-elector George II and built on a converted fortification tower, with usable, but partly out-of-date instruments.", "The construction of a new observatory had been approved by Prince-elector George III in principle since 1802, and the Westphalian government continued the planning, but Gauss could move to his new place of work not until October 1816.He got new up-to-date instruments, for instance two meridian circles from Repsold and Reichenbach, and a heliometer from Fraunhofer.The scientific activity of Gauss, besides pure mathematics, can be roughly divided into three periods: in the first two decades of the 19th century astronomy was the main focus, in the third decade geodesy, and in the fourth decade he occupied himself with physics, mainly magnetism.Gauss remained mentally active into his old age, even while suffering from gout and general unhappiness.", "His last observation was the solar eclipse of July 28, 1851.On 23 February 1855, Gauss died of a heart attack in Göttingen; he is interred in the Albani Cemetery there.", "Heinrich Ewald, Gauss's son-in-law, and Wolfgang Sartorius von Waltershausen, Gauss's close friend and biographer, gave eulogies at his funeral.=== Gauss's brain ===The day after Gauss's death his brain was removed, preserved and studied by Rudolf Wagner, who found its mass to be slightly above average, at .", "The cerebral area was determined by Wagner's son Hermann in his doctoral thesis to be .", "Highly developed convolutions were also found, which in the early 20th century were suggested as the explanation for his genius.", "After various previous investigations, a magnetic resonance study of 1998, done at the Max Planck Institute for Biophysical Chemistry in Göttingen, gave no results which could be used to explain his mathematical abilities.In 2013, a neurobiologist at the same institute discovered that Gauss's brain had been mixed up, due to mislabelling, with that of the physician Conrad Heinrich Fuchs, who died in Göttingen a few months after Gauss.", "A further investigation showed no remarkable anomalies in the brains of either person.", "Thus, all investigations on Gauss's brain until 1998, except the first ones of Rudolf and Hermann Wagner, actually refer to the brain of Fuchs.=== Family ===Ludwig BeckerGauss married Johanna Osthoff (1780–1809) on 9 October 1805.They had two sons and a daughter: Joseph (1806–1873), Wilhelmina (1808–1840) and Louis (1809–1810).", "Johanna died on 11 October 1809 one month after the birth of Louis, who himself died a few months later.Gauss remarried within a year, on 4 August 1810, to Wilhelmine (Minna) Waldeck (1788–1831), a friend of his first wife.", "They had three more children: Eugen (later Eugene) (1811–1896), Wilhelm (later William) (1813–1879) and (1816–1864).", "Minna Gauss died on 12 September 1831 after being seriously ill for more than a decade.", "Therese then took over the household and cared for Gauss for the rest of his life; after her father's death she married the actor Constantin Staufenau.", "Her sister Wilhelmina married the orientalist Heinrich Ewald.", "Gauss' mother Dorothea lived in his house from 1817 until her death in 1839.The eldest son Joseph, whilst still a schoolboy, helped his father as an assistant during his survey campaign in summer 1821.After a short time at university, in 1824 Joseph joined the Hanoverian army and assisted in surveying again in 1829.In the 1830s he was responsible for the enlargement of the survey network to the western parts of the kingdom.", "With his geodetical qualifications he left the service and engaged in the construction of the railway network as director of the Royal Hanoverian State Railways.", "In 1836 he studied the railroad system in the US for some months.Eugen left Göttingen in September 1830 and emigrated to the United States, where he joined the army for five years.", "He then worked for the American Fur Company in the Midwest, where he learned the Sioux language.", "Later, he moved to Missouri and became a successful businessman.", "Wilhelm married a niece of the astronomer Bessel and also moved to Missouri in 1837, starting as a farmer and later becoming wealthy in the shoe business in St. Louis.", "Eugene and William have numerous descendants in America, but the descendants left in Germany all derive from Joseph, as the Gauss daughters had no children.=== Personality ======= The scholar ====sealAt the end of the 18th century, German academic mathematics was in a poor condition: the prolific mathematicians of that time worked in France and other European countries.", "The mathematical mainstream mainly dealt with solving practical problems in mechanics, astronomy, geodesy, etc.", "In this scientific environment, Gauss can be seen, following Felix Klein, as typical of both 18th and 19th-century mathematicians.", "His interest in practical applicability, for example in geodesy and astronomy, qualified Gauss to be taken as a typical applied mathematician of the century of enlightenment.", "On the other hand, he began research in numerous parts of mathematics without defined links to practical purposes, and thus showed himself as a pioneer of what was later called \"pure mathematics\".", "In contrast to earlier mathematicians, such as Leonhard Euler—who let their readers take part in their reasoning as they developed new ideas, and included certain erroneous deviations from the correct path—Gauss developed a new style of direct and complete explanation that did not attempt to show the reader the author's train of thought.", ":\"Gauss was the first to restore that ''rigor'' of demonstration which we admire in the ancients and which had been forced unduly into the background by the exclusive interest of preceding period in ''new'' developments.", "\"But for himself, he propagated a quite different ideal, given in a letter to Farkas Bolyai as follows:Gauss refused to publish work which he did not consider complete and above criticism.", "This perfectionism was in keeping with the motto of his personal seal (\"Few, but Ripe\").", "His personal diary indicates that he had made several mathematical discoveries years or decades before contemporaries published them.", "He put down new ideas in writing to his colleagues, who encouraged him to publish, and sometimes rebuked him if he hesitated too long, in their opinion.", "Gauss defended himself, claiming that the initial discovery of ideas was easy, but preparing a publishable elaboration was a demanding matter for him, for either lack of time or \"serenity of mind\".", "Nevertheless, he published many short communications of urgent content in various journals, but his \"Collected Works\" contain a considerable literary estate, too.", "Eric Temple Bell said that if Gauss had published all of his discoveries in a timely manner, he would have advanced mathematics by fifty years.On certain occasions, Gauss claimed that a finding published by another scholar had already been in his possession previously.", "Thus his concept of priority as \"the first to discover, not the first to publish\" differed from that of his scientific contemporaries.", "In contrast to his perfectionism in presenting mathematical ideas, he was criticized for his negligent way of quoting.", "He justified himself with a very special view of correct quoting: if he gave references, then only in a quite complete way, with respect to the previous authors of importance, which no one should ignore; but quoting in this way needed knowledge of the history of science and more time than he wished to spend.A sketch of Gauss by his student Johann Benedict Listing, 1830Though Gauss is seen as a master of axiomatic presentation, it became obvious from his posthumously published papers, his diary, and short glosses in his own textbooks, that he worked to a great extent in an empirical way.", "Gauss was a lifelong busy and enthusiastic calculator, who made his calculations with extraordinary rapidity, mostly without precis controlling, but checked the results by masterly estimation.", "Nevertheless, his calculations, especially in geodesy and astronomy, were not always free from mistakes.", "He coped with the enormous workload by using skillful tools.", "Gauss used a lot of mathematical tables, examined their exactness, and constructed new tables on various matters for personal use.", "He developed new tools for effective calculation, for example the Gaussian elimination.", "It has been taken as a curious feature of his working style that he carried out calculations with a high degree of precision, much more than required.", "Very likely, this method gave him a lot of material which he used in finding theorems in number theory.It was well known to his close colleagues that Gauss disliked giving academic lectures.", "He first stated this to Olbers in 1802, so this aversion was not the result of bad experience.", "Thus he refused to accept any academic position with teaching duties during his years as a private scholar.", "But from the start of his academic career at Göttingen in 1807, he continuously gave lectures until 1854.He often complained about the efforts of teaching, feeling that it was a waste of his time, but on the other hand he occasionally described one or other student as talented.", "In all these 47 years of teaching he gave only three lectures on subjects of pure mathematics, whereas most of his lectures dealt with astronomy, geodesy, and applied mathematics.", "However, many of Gauss' students went on to become renowned mathematicians, physicists, and astronomers: Moritz Cantor, Dedekind, Dirksen, Encke, Gould, Heine, Klinkerfues, Kupffer, Listing, Möbius, Nicolai, Riemann, Ritter, Schering, Scherk, Schumacher, Seeber, von Staudt, Stern, Ursin; as geoscientists Sartorius von Waltershausen and Wappäus.Gauss did not write any textbook, and (unlike his friends Bessel, Humboldt, and Olbers) he disliked the popularization of scientific matters.", "His only attempts at popularization were his works on the date of Easter and the essay ''Erdmagnetismus und Magnetometer'' of 1836.Gauss published his papers and books exclusively in Latin or in German.", "He wrote Latin in a merely classical style, but used some customary modifications set by contemporary mathematicians.The new Göttingen Observatory of 1816; Gauss' living rooms were in the western wing (right)At Göttingen University, Gauss was accompanied by a staff of other lecturers in his disciplines, who completed the educational program: for instance the brilliant Thibaut in mathematics, in physics Weber and Mayer, well known for his successful textbooks, and Harding, who took the main part of lectures in astronomy.", "When the observatory was completed, Gauss took his living accommodation in the western wing of the new observatory and Harding in the eastern one.", "Once they had been on friendly terms with another, but in the course of time they became alienated, possibly – as some biographers presume – because Gauss had wished the equal-ranked Harding to be no more than his assistant or observer.", "The years since 1820 were evaluated as a \"period of lower astronomical activity\".", "The new, well-equipped observatory did not work as effectively as others; Gauss' astronomical research had the character of a one-man enterprise, and the university established a place for an assistant only after Harding's death in 1834.But nevertheless Gauss twice refused the opportunity to solve the problem by accepting offers from Berlin in 1810 and 1825 to become a full member of the Prussian Academy, without no great lecturing duties, as well as from Leipzig University in 1810 and from Vienna University in 1842.Perhaps the reason was the difficult situation of his family.", "In his later years, Gauss was one of the best-paid professors of the university.When Gauss was asked for help by his colleague and friend Friedrich Wilhelm Bessel in 1810, who was in trouble at Königsberg University because of his lack of an academic title, Gauss provided a doctorate ''honoris causa'' for Bessel from the Philosophy Faculty of Göttingen in March 1811.Gauss gave another recommendation for an honorary degree for Sophie Germain, but only shortly before her death, so she never received it.", "He also gave successful support for the talented mathematician Gotthold Eisenstein in Berlin.Gauss took part in academic administration: three times he was elected as dean of the Philosophy Faculty.", "Being entrusted with the widow's pension fund of the university, he dealt with actuarial science and wrote a report on the strategy for stabilizing the benefits.", "He was appointed director of the Royal Academy of Sciences in Göttingen for nine years, even in his last year of life.==== The private man ====Soon after Gauss' death, his friend Sartorius published the first biography (1856), written in a rather enthusiastic style.", "Sartorius saw Gauss as a serene and forward-striving man with childlike modesty, but also of \"iron character\" with an unshakeable strength of mind.", "He was noted for a sense of justice and religious tolerance.", "Apart from his closer circle, others regarded him as reserved and unapproachable, \"like an Olympian sitting enthroned on the summit of science\".", "His close contemporaries agreed that Gauss was a man of difficult character.", "He often refused to accept compliments.", "His visitors were occasionally irritated by grumpy behaviour, but a short time later his mood could change, and he became a charming, open-minded host.Gauss' second wife Wilhelmine WaldeckGauss' life was overshadowed by severe problems in his family.", "When his first wife Johanna suddenly died shortly after the death of their third child, he plunged into a depression from which he never fully recovered.", "Soon after her death he wrote a last letter to her in the style of an ancient threnody, the most personal surviving document of Gauss'.", "The situation worsened when tuberculosis afflicted, and ultimately destroyed the health of, his second wife Minna over 13 years; both his daughters later suffered from the same disease.", "Both younger sons were educated for some years in Celle far from Göttingen.", "Gauss himself gave only slight hints of his personal distress: in a letter to Bessel dated December 1831 he described himself as \"the victim of the worst domestic sufferings\".Gauss grew to dominate his children and eventually had conflicts with his sons, because he did not want any of them to enter mathematics or science for \"fear of lowering the family name\", as he believed none of them would surpass his own achievements.", "The military career of his elder son Joseph ended after more than two decades with the rank of a poorly paid first lieutenant, although he had acquired a considerable knowledge of geodesy.", "He needed financial support from his father even after he was married.", "The second son Eugen shared a good measure of Gauss' talent in computation and languages, but had a vivacious and sometimes rebellious character.", "He wanted to study philology, whereas Gauss wanted him to become a lawyer.", "Having run up debts and caused a scandal in public, he suddenly left Göttingen under dramatic circumstances in September 1830 and emigrated via Bremen to the United States.", "He wasted the little money he had taken for starting, after which his father refused further financial support.", "The youngest son Wilhelm wanted to qualify for agricultural administration, but had difficulties to get an appropriate education, and emigrated as well.", "Only Gauss' youngest daughter Therese accompanied him in his last years of life.Collecting numerical data on very different things, useful or useless, became a habit in his later years, for example the number of paths from his home to certain places in Göttingen, or the numbers of living days of persons; he congratulated Humboldt in December 1851, when he had reached the same age as Isaac Newton at his death, calculated in days.Similar to his excellent knowledge of Latin he was also acquainted with modern languages.", "At the age of 62, he began to teach himself Russian, very likely to understand scientific writings from Russia, among them those of Lobachevsky on non-Euclidean geometry.", "Gauss read both classical and modern literature, the English and French in the original languages.", "His favorite English author was Walter Scott, his favorite German Jean Paul.", "Gauss liked singing and went to concerts.", "He was a busy newspaper reader, and in his last years he used to visit an academic press salon of the university every noon.", "Gauss did not care much for philosophy, and mocked the \"splitting hairs of the so-called metaphysicians\", by which he meant proponents of the contemporary school of ''Naturphilosophie''.Gauss had an \"aristocratic and through and through conservative nature\", with little respect for people's intelligence and morals, in accordance with the motto \"mundus vult decipi\".", "He disliked Napoleon and his system, and all kind of violence and revolution caused horror to him.", "Thus he condemned the methods of the Revolutions of 1848, though he agreed with some of their aims, such as the idea of a unified Germany.", "As far as the political system is concerned, he had a low estimation of the constitutional system; he criticized parliamentarians of his time for a lack of knowledge and logical errors.Gauss was loyal to the House of Hanover.", "After King William IV's death in 1837, the personal union between the kingdoms of Great Britain and Ireland and Hanover ceased.", "In the same year, the new Hanoverian King Ernest Augustus annulled the constitution given to the state by his brother in 1833.Seven prominent professors, later known as the \"Göttingen Seven\", protested against this, among them Gauss' friend and collaborator Wilhelm Weber and Gauss' son-in-law Heinrich Ewald.", "All of them were dismissed, three of them were expelled, but Ewald and Weber could stay in Göttingen.", "Ewald took a position the University of Tübingen in 1838, where Gauss' daughter Wilhelmina died soon afterwards in 1840, and Weber went to the University of Leipzig in 1843; but both of them returned to their Göttingen positions in 1849 as the only ones of the Göttingen Seven.", "Gauss was deeply affected by this quarrel, but saw no possibility to help them.Gauss' religious beliefs have been a subject of speculation by some of his biographers.", "He sometimes said: \"God is calculating.\"", "and: \"I succeeded - not on account of my hard efforts, but by the grace of the Lord.\"", "Gauss was a member of the Lutheran church, like most of the population in northern Germany, but it seems that he did not believe all dogmas or understand the Holy Bible to be true quite literally.", "Sartorius mentioned Gauss' religious tolerance, and estimated his \"insatiable thirst for truth\" and his sense of justice as motivated by religious convictions.Gauss was a successful investor and accumulated considerable wealth with stocks and securities, but he disapproved of the idea of paper money.", "After his death a great sum of money was found hidden in his rooms." ], [ "Scientific work", "=== Algebra and number theory ======= Fundamental theorem of algebra ====In his doctoral thesis from 1799 Gauss proved the fundamental theorem of algebra which states that every non-constant single-variable polynomial with complex coefficients has at least one complex root.", "Mathematicians including Jean le Rond d'Alembert had produced false proofs before him, and Gauss' dissertation contains a critique of d'Alembert's work.", "He subsequently produced three other proofs, the last one in 1849 being generally rigorous.", "His attempts clarified the concept of complex numbers considerably along the way.==== Disquisitiones Arithmeticae ====German stamp commemorating Gauss' 200th anniversary: the complex planeThe entries in Gauss' Mathematical diary indicate that he was busy with the subject of number theory at least since 1796.A detailed study of previous researches showed him that some of his findings had been already done by other scholars.", "In the years 1798 and 1799 Gauss wrote a voluminous compilation of all these results in the famous ''Disquisitiones Arithmeticae'', published in 1801, that was fundamental in consolidating number theory as a discipline and covered both elementary and algebraic number theory.", "Therein he introduces, among other things, the triple bar symbol () for congruence and uses it in a clean presentation of modular arithmetic.", "It deals with the unique factorization theorem and primitive roots modulo n. In the main chapters, Gauss presents the first two proofs of the law of quadratic reciprocity, which allows mathematicians to determine the solvability of any quadratic equation in modular arithmetic, and develops the theories of binary and ternary quadratic forms.Highlights of these theories include the remarkable Gauss composition law for binary quadratic forms, as well as his enumeration of the number of representations of an integer as sum of three squares.", "As an almost immediate corollary of his theorem on three squares, he proves the triangular case of the Fermat polygonal number theorem for ''n'' = 3.From several remarkable analytic results on class numbers that Gauss gives without proof towards the end of the fifth chapter, it appears that Gauss already knew the class number formula in 1801.In the last chapter Gauss gives his proof for the constructibility of a regular heptadecagon (17-sided polygon) with straightedge and compass by reducing this geometrical to an algebraic problem.", "He shows that a regular polygon is constructible if the number of its sides is a product of distinct Fermat primes and a power of 2.In the same chapter, he gives a result on the number of solutions of certain cubic polynomials with coefficients in finite fields, which amounts to counting integral points on an elliptic curve.", "Some 150 years later, Andre Weil remarked that this particular result, together with some other unpublished results of Gauss, led him to formulate what is now called Weil conjectures.Gauss intended to include an eighth chapter that would treat the topic of higher congruences modulo a prime number in its full generality, but the unfinished chapter was found among his papers only after his death, consisting of work done during the years 1797–1799.==== Further investigations ====In 1831, Ludwig August Seeber published a book on the theory of reduction of positive ternary quadratic forms, with accordance with the program outlined in Gauss's ''Disquisitiones''.", "However, he did not prove a central theorem of his theory, so it remained a mere conjecture.", "In his review of Seeber's book, Gauss simplified many of Seeber's lengthy arguments, proved this central conjecture, and remarked that this theorem is equivalent to Kepler conjecture for regular arrangements.Gauss proved Fermat's Last Theorem for ''n'' = 3 and sketchingly proved it for ''n'' = 5 in his unpublished writings.", "The particular case of ''n'' = 3 was proved much earlier by Leonhard Euler, but Gauss developed a more streamlined proof which made use of Eisenstein integers; though more general, the proof was simpler than in the real integers case.In his two important papers on biquadratic residues (published in 1828 and 1832) Gauss introduces the ring of Gaussian integers , and shows that this ring is a unique factorization domain.", "Furthermore, he generalizes into this ring many key arithmetic concepts, such as Fermat's little theorem and Gauss's lemma.", "The main objective of introducing this ring was to formulate the law of biquadratic reciprocity – as Gauss discovered, rings of complex integers are the natural setting for such higher reciprocity laws.In the second paper, he states the general law of biquadratic reciprocity and proves several special cases of it, but proof of the general theorem is lacking, despite Gauss's statements that he found such a proof around 1814.He promised a third paper with a general proof, but this never appeared.", "In an earlier publication from 1818 containing his fifth and sixth proofs of quadratic reciprocity, he claims the techniques of these proofs (Gauss sums) can be applied to prove higher reciprocity laws.Gauss's publications on biquadratic residues opened the way for boundless enlargement of the theory of numbers, and are memorable for the wealth of investigations in \"higher arithmetic\" that they led to.=== Analysis ===One of Gauss's first independent discoveries was the notion of the arithmetic-geometric mean (AGM) of two positive real numbers; his systematic investigations on the AGM led him to discover an unusually rich mathematical landscape, and to obtain plenty of new results associated with it.", "He discovered its relation to elliptic integrals in the years 1798-1799 through the so-called Landen's transformation, and in a diary entry recorded his discovery of the connection of Gauss's constant to lemniscatic elliptic functions, a result that Gauss stated that \"will surely open a new area of analysis\".", "He also made early inroads into the more formal issues of the foundations of complex analysis, and from a letter to Bessel in 1811 it is clear that he knew the so-called \"fundamental theorem of complex analysis\" - Cauchy's integral theorem - and understood the notion of complex residues when integrating around poles.Another source of inspiration for Gauss's early work in analysis was his acquaintance with Euler's pentagonal numbers theorem.", "This theorem together with his other researches on the AGM and lemniscatic functions led him to plenty of results on Jacobi theta functions, work which culminated with his discovery in 1808 of the later called Jacobi triple product identity, which includes Euler's theorem as a special case.", "In his publication from 1811 on the determination of the sign of quadratic Gauss sum, Gauss solved the problem by introducing Gaussian binomial coefficients and by using a line of reasoning that somehow \"hides\" its origin in theta function theory, as later mathematicians have shown.", "All this work was done several decades before the publication of Jacobi's \"Fundamenta nova\" in 1829; however, Gauss never found the time to systematically write and organize all his thoughts and theorems of this kind, and his contemporaries never knew the scope of his work.Several mathematical fragments in his Nachlass indicate that he knew quite well parts of the modern theory of modular forms of Felix Klein and Robert Fricke.", "In his work on the multivalued AGM of two complex numbers, he discovered a very deep connection between the infinitely many values of the AGM to its two \"simplest values\".", "His unpublished writings include several drawings that show he was quite aware of the geometric side of the theory; in the context of his work on the complex AGM he recognized and made a sketch of the key concept of fundamental domain for the modular group.", "One of Gauss's sketches of this kind was his drawing of a tessellation of the unit disk by \"equilateral\" hyperbolic triangles with all angles equal to .In his lifetime Gauss published almost nothing about those more modern theories of elliptic functions, but he did publish most of his results on the related theme of the hypergeometric function.", "In his work \"Disquisitiones generales circa series infinitam...\" (1812), he provided the first systematic treatment of the general hypergeometric function , and showed that many of the functions known to science at the time, such as the elementary functions and some special functions, are a special case of the hypergeometric function.", "This work was the first one with an exact inquiry of convergence of infinite series in the history of mathematics.", "Furthermore, it dealt with infinite continued fractions arising as ratios of hypergeometric functions.In 1822 Gauss published his prize winning essay on conformal mappings, which contains several developments that pertain to the field of complex analysis.", "In this essay, Gauss made explicit the insight that angle-preserving mappings in the complex plane must be complex analytic functions, and used the so-called Beltrami equation to prove the existence of isothermal coordinates on analytic surfaces.", "The essay concludes with examples of conformal mappings into a sphere and an ellipsoid of revolution.", "In addition, in unpublished fragments from the years 1834-1839 he investigated and solved the more difficult task of explicitly constructing a conformal mapping from the interior of an ellipse to the unit disk.", "His solution, which combined his early work on elliptic functions and his later ideas on potential theory, reveals his mastery of the theory of logarithmic potential, and his final results corresponded to the formula found by Hermann Schwarz in 1870.==== Numeric analysis ====Gauss often deduced theorems inductively from numerical data he had collected in an empirical way.", "As such, the use of efficient algorithms to facilitate calculations was vital to his researches, and he made many contributions to numeric analysis.", "In 1815, he published an article on numeric integration, in which he described his method of Gaussian quadrature, that greatly improved existing methods and inspired much of the work made by later mathematicians.In a private letter to Gerling from 1823, he described a solution of a certain 4X4 system of linear equations by using Gauss-Seidel method – an \"indirect\" iterative method for the solution of linear systems, that in some cases converges very rapidly to the exact solution.", "Gauss recommended it over the usual method (the so-called \"direct elimination\") for systems of more than 2 equations, stating that it can be done \"while half asleep, or while thinking about other things\".", "As such, it was an early contribution to numerical linear algebra.Gauss invented an algorithm for calculating what are now called discrete Fourier transforms, sometimes called \"the most important numerical algorithm of our lifetime\", when calculating the orbits of Pallas and Juno in 1805, 160 years before Cooley and Tukey published their similar Cooley–Tukey FFT algorithm.", "He developed it as a trigonometric interpolation method, but his paper ''Theoria Interpolationis Methodo Nova Tractata'' was published only posthumously in 1866, preceded by the first presentation by Joseph Fourier on the subject in 1807.=== Chronology ===The first publication following the doctoral thesis dealt with the determination of the date of Easter (1800), a very elementary matter of mathematics.", "Gauss aimed to present a most convenient algorithm for people without any knowledge in ecclesiastical or even astronomical chronology, and thus avoided the usually required terms of golden number, epact, solar cycle, domenical letter, and any religious connotations.", "Biographers speculated on the reason why Gauss dealt with this matter, but it is likely comprehensible by the historical background.", "The replacement of the Julian calendar by the Gregorian calendar had caused great confusion to the hundreds of states of the Holy Roman Empire since the 16th century, and was finished in Germany not until the year 1700, when the difference of eleven days was deleted, but the difference in calculating the date of Easter remained between Protestant and Catholic territories.", "A further agreement of 1776 equalized the confessional way of counting, thus in the Protestant states like the Duchy of Brunswick the Easter of 1777, five weeks before Gauss' birth, was the first one calculated in the new manner.", "The public difficulties of replacement may be the historical background for the confusion on this matter in the Gauss family (see chapter: Anecdotes).", "For being connected with the Easter regulations, an essay on the date of Pesach followed soon in 1802.Carl Friedrich Gauss 1803 by Johann Christian August Schwartz=== Astronomy ===On 1 January 1801, Italian astronomer Giuseppe Piazzi discovered the dwarf planet Ceres.", "Piazzi could track Ceres for only somewhat more than a month, following it for three degrees across the night sky, less than 1% of the total orbit, until it disappeared temporarily behind the glare of the Sun.", "Several months later, when Ceres should have reappeared, Piazzi could not locate it: the mathematical tools of the time were not able to extrapolate a position from such a scant amount of data.", "Gauss tackled the problem within three months of intense work, and predicted a position for Ceres in December 1801.This turned out to be accurate within a half-degree when it was rediscovered by Franz Xaver von Zach on 7/31 December at Gotha, and independently by Heinrich Olbers on 1/2 January in Bremen.", "This confirmation eventually led to the classification of Ceres as minor-planet designation 1 Ceres; that was taken as the predicted planet between Mars and Jupiter by the most speculative Titius–Bode law.Gauss's method involved determining a conic section in space, given one focus (the Sun) and the conic's intersection with three given lines (lines of sight from the Earth, which is itself moving on an ellipse, to the planet) and given the time it takes the planet to traverse the arcs determined by these lines (from which the lengths of the arcs can be calculated by Kepler's Second Law).", "This problem leads to an equation of the eighth degree, of which one solution, the Earth's orbit, is known.", "The solution sought is then separated from the remaining six based on physical conditions.", "In this work, Gauss used comprehensive approximation methods which he created for that purpose.", "Zach noted that \"without the intelligent work and calculations of Doctor Gauss we might not have found Ceres again\".The discovery of Ceres led Gauss to his work on a theory of the motion of planetoids disturbed by large planets, eventually published in 1809 as ''Theoria motus corporum coelestium in sectionibus conicis solem ambientum''.", "In the process, he so streamlined the cumbersome mathematics of 18th-century orbital prediction that his work remains a cornerstone of astronomical computation.", "It introduced the Gaussian gravitational constant.Since the new asteroids had been discovered, Gauss occupied himself with the perturbations of their orbital elements.", "Firstly he examined Ceres with analytical methods similar to those of Laplace, but his favorite object was Pallas, because of its great eccentricity and orbital inclination, whereby Laplace's method did not work.", "Gauss used his own tools : the arithmetic–geometric mean, the hypergeometric function, and his method of interpolation.", "He found an orbital resonance with Jupiter in proportion 18 : 7 in 1812; Gauss published this result as cipher, and gave the explicit meaning only in letters to Olbers and Bessel.", "However, after long years he finished his work in 1816 without a result that seemed sufficient to him.", "This marked the end of his activities in theoretical astronomy, too.One fruit of Gauss's research on Pallas perturbations was his article ''Determinatio Attractionis...'' (1818) on a method of theoretical astronomy that later became known as the \"elliptic ring method\".", "This method introduced a useful averaging conception in which a planet in orbit is replaced by a fictitious ring with mass density proportional to the time taking the planet to follow the corresponding orbital arcs.", "Gauss presents his method of evaluating the gravitational attraction of such an elliptic ring, which includes several complicated steps; one such step involves a direct application of the arithmetic-geometric mean (AGM) algorithm to calculate an elliptic integral.", "In the late 19th century Gauss's method was adapted by American astronomer George William Hill, who applied it directly to the problem of secular perturbation induced by Venus on Mercury orbit.While Gauss's contributions to theoretical astronomy came to a marked end in 1818, his more practical activities in observational astronomy continued and occupied him during his entire career.", "As early as 1799 he did some important work, recorded in entry 97 of his diary, on determining the lunar parallax in any place on Earth by reducing it to a collection of useful formulas, which improved the accuracy of the method of determining geographical location by observing the position of the Moon.", "Later on, he attached importance to revising the values of fundamental astronomical constants, and thereby worked on diverse topics such as the precession and nutation constants, the obliquity of the ecliptic, the proper motion of the Solar System, constructing better stellar aberration tables, as well as the evaluation of the effect of atmospheric refraction on apparent star positions.=== Theory of errors ===It is likely that Gauss used the method of least squares for calculating the orbit of Ceres to minimize the impact of measurement error.", "The method was published first by Adrien-Marie Legendre in 1805, but Gauss claimed in ''Theoria motus'' (1809) that he had been using it since 1794 or 1795.In the history of statistics, this disagreement is called the \"priority dispute over the discovery of the method of least squares\".", "Gauss proved the method under the assumption of normally distributed errors (Gauss–Markov theorem) in his paper ''Theoria combinationis observationum erroribus minimis obnoxiae'' from 1821.In this paper, which was relatively little known in the English speaking world in the first century after its publication, he stated and proved Gauss's inequality (a Chebyshev-type inequality) for unimodal distributions, and stated without proof another inequality for moments of the fourth order (a special case of Gauss-Winckler inequality).", "He derived lower and upper bounds for the variance of sample variance.", "In a supplement to this paper Gauss described recursive least squares methods that went unnoticed until 1950, when his work was rediscovered as a consequence of the growing demand of quick estimation for various new technologies.", "Gauss's work on the theory of errors was extended in several directions by the geodesist Friedrich Robert Helmert, and the Gauss-Helmert theory is considered today as the \"classical\" theory of errors.Gauss made several striking contributions to problems in probability theory that are not directly concerned with the theory of errors, but offer a glimpse into his broad minded view on the applicability of probabilistic thinking.", "One remarkable example appears as a note in his diary and is concerned with a very unusual problem that came to his mind: to describe the asymptotic distribution of entries in the continued fraction expansion of a random number uniformly distributed in ''(0,1)''.", "He derived this distribution, now known as the Gauss-Kuzmin distribution, as a by-product of his discovery of the ergodicity of the Gauss map for continued fractions.", "Gauss's solution is the first ever result in the metrical theory of continued fractions.Order of King George IV to the triangulation project=== Arc measurement and geodetic survey ===Gauss was busy with geodetic problems since 1799, when he helped Karl Ludwig von Lecoq with calculations during his survey in Westphalia.", "Later since 1804, he taught himself some geodetic practise with a sextant in Brunswick, and Göttingen.Since 1816, his former student Heinrich Christian Schumacher, then professor in Copenhagen, but living in Altona (Holstein) near Hamburg, made a triangulation of the Jutland peninsula from Skagen in the north to Lauenburg in the south.", "The aim was not only the foundation of map production, but also the determination of the geodetic arc of that distance.", "Schumacher asked Gauss to continue this work further to the south and said he could find support for this project directly from the government of Hanover.", "Finally in May 1820, King George IV gave the order to Gauss.Gauss and Schumacher had yet determined some angles between Lüneburg, Hamburg, and Lauenburg for the geodetic connection in October 1818.During the summers of 1821 until 1825 Gauss directed the triangulation personally, that reached from Thuringia in the south to the river Elbe in the north.", "The triangel between Hoher Hagen, Großer Inselsberg in the Thuringian Forest, and Brocken in the Harz mountains was the largest one Gauss had ever measured with a maximum side of .", "In the thin populated Lüneburg Heath, without significant natural summits or artificial buildings, he had great difficulties to find suitable triangulation points, sometimes cutting lanes through the vegetation was necessary or even the erection of signal towers.heliotropeTroughton sextant with additional mirrorFor pointing signals, Gauss invented a new instrument with movable mirrors and a small telescope that reflects the sunbeams to the triangulation points, and named it ''heliotrope''.", "Another suitable construction for the same purpose was a sextant with an additional mirror which he named ''vice heliotrope''.", "Gauss got assistance by soldiers of the Hanoveran army, among them his eldest son Joseph.", "Gauss took part in the baseline measurement (Braak Base Line) of Schumacher in the village Braake= near Hamburg in 1820, and used the result for the evaluation of his triangulation.The arc measurement needed a precise astronomical determination of two points in the network.", "Gauss and Schumacher used the favourite occasion that both observatories in Göttingen and in Altona, in the garden of Schumacher's house, laid nearly in the same longitude.", "The latitude was measured with both their own instruments and a zenith sector of Ramsden that was transported to both observatories.An additional result was a better value of flattening of the approximative earth ellipsoid.", "Gauss developed the universal transverse Mercator projection of the ellipsoidal shaped earth (what he named ''conform projection'') for representing geodetical data in plane charts.When the arc measurement was finished, Gauss intended the enlargement of the triangulation to the west to get a survey of the whole Kingdom of Hanover.", "The practical work was directed by three army officers, among them Lieutenant Joseph Gauss.", "The complete data evaluation laid in the hands of Carl Friedrich Gauss, who applied his mathematical inventions as the method of least squares and his elimination method to it.", "The project was finished in 1844, but Gauss did not publish a final report of the project and his method of projection; this work was not done until 1866.In 1828, when studying differences in latitude, Gauss first defined a physical approximation for the figure of the Earth as the surface everywhere perpendicular to the direction of gravity; later his doctoral student Johann Benedict Listing called this the ''geoid''.=== Differential geometry ===The geodetic survey of Hanover fueled Gauss' interest in differential geometry and topology, fields of mathematics dealing with curves and surfaces.", "This led him in 1828 to the publication of a memoir that marks the birth of modern differential geometry of surfaces, as it departed from the traditional ways of treating surfaces as cartesian graphs of functions of two variables, and instead pioneered a revolutionary approach that initiated the exploration of surfaces from the \"inner\" point of view of a two-dimensional being constrained to move on it.", "Its crowning result, the Theorema Egregium (''remarkable theorem''), established a property of the notion of Gaussian curvature.", "Informally, the theorem says that the curvature of a surface can be determined entirely by measuring angles and distances on the surface.", "That is, curvature does not depend on how the surface might be embedded in 3-dimensional space or 2-dimensional space.The Theorema Egregium leads to the abstraction of surfaces as doubly-extended manifolds - it makes clear the distinction between the intrinsic properties of the manifold (the metric) and its physical realization (the embedding) in ambient space.", "A consequence is the impossibility of an isometric transformation between surfaces of different Gaussian curvature.", "This means practically that a sphere or an ellipsoid cannot be transformed to a plane without distortion, what causes a fundamental problem in designing projections for geographical maps.An additional significant portion of his essay is dedicated to a profound study of geodesics.", "In particular, Gauss proves the local Gauss-Bonnet theorem on geodesic triangles, and generalizes Legendre's theorem on spherical triangles to geodesic triangles on arbitrary surfaces with continuous curvature; he found that the angles of a \"sufficiently small\" geodesic triangle deviate from that of a planar triangle of the same sides in a way that depends only on the values of the surface curvature at the vertices of the triangle - regardless of the behaviour of the surface in the triangle interior.One key differential geometric conception was lacking from Gauss's memoir, that of geodesic curvature.", "However, his posthumous papers show that this notion did not escape his mind, and in the years of composing his memoir he also wrote up a manuscript in which he introduced it and referred to it as \"side curvature\" (in German: \"Seitenkrümmung\").", "More importantly, he proved its invariance under isometric transformations, a result later obtained by Ferdinand Minding.", "Based on this evidence and the announcement in his memoir of further investigations on the curvature integral, it is very likely that he knew the more general version of the Gauss-Bonnet theorem proved by Pierre Ossian Bonnet in 1848, which is closer in spirit to the global version of this theorem.=== Non-Euclidean geometries===Lithography by Siegfried Bendixen (1828)In the lifetime of Gauss a vivid discussion on Euclid‘s parallel axiom was going on.", "Numerous mathematicians made efforts to prove it, whereas some of them discussed the possibility of geometrical systems without it.", "Gauss himself was only interested in the geometrical aspects of the physical space, but did not care about the philosophical aspects of an enlarged geometry.", "In 1816, he gave his first short public comment on this matter in a book review, and in the follwing time he occasionally made some remarks in letters to his correspondents.", "He is the one who coined the term \"non-Euclidean geometry\".Not until Lobachevsky (1829) and Janos Bolyai (1832) had published their ideas of a non-Euclidean geometry – for the first time in history of mathematics – , Gauss himself put down his ideas, but avoided any influence to the contemporary scientific discussion, because he did not publish about it.", "Gauss commended the ideas of Janos Bolyai in a letter to his father, claiming that these were congruent to his own thoughts since some decades.", "But it is not clear to what extent he preceded Lobachevsky and Bolyai, for he gave only vague and obscure remarks on it in his letters.Sartorius mentioned it first in 1856, but only the edition of left papers in Volume VIII of his Collected Works (1900) showed Gauss's own progress on that matter, at a time when Non-Euclidean geometry had yet grown out of controversial discussion.In 1854, Gauss selected the topic for Bernhard Riemann's inaugural lecture from three proposals.", "On the way home from Riemann's lecture, Weber reported that Gauss was full of praise and excitement.=== Early topology ===One of the lesser known aspects of Gauss's work is that he was also an early pioneer of topology, or as it was called in his lifetime, ''Geometria Situs''.", "His first proof of the fundamental theorem of the algebra contained an essentially topological argument; fifty years later, he further developed the topological argument in his fourth proof of this theorem (in 1849).His earliest \"serious\" encounter with topological notions occurred to him in the course of his astronomical work, and in a small article from 1804 he determined the limits of the region on the celestial sphere in which comets and asteroids might appear, region which he termed \"Zodiacus\".", "He determined this region, and observed that if the Earth's and comet's orbits are linked, then by topological reasons the Zodiacus is the entire sphere.", "In 1848, in the context of the discovery of the asteroid 7 Iris, he published another short article in which he further elaborated the qualitative discussion of the Zodiacus.From Gauss's letters during the period of 1820–1830, one can learn that he thought intensively on topics with close affinity to Geometria Situs, and became gradually conscious of semantic difficulty in this field.", "Fragments from this period reveal that he tried to classify \"Tractfigurens\", which are closed plane curves with a finite number of transverse self-intersections, that may also be planar projections of knots.", "To do so he devised a symbolical scheme, the so-called Gauss code, that in a sense captured the characteristic features of tract figures.In a fragment from 1833, Gauss defined the linking number of two space curves by a certain double integral, and in doing so provided for the first time an analytical formulation of a topological phenomenon.", "In the same note, he lamented on the little progress made in Geometria Situs, and remarked that one of its central problems will be \"to count the intertwinings of two closed or infinite curves\".", "His notebooks from that period reveal that he was also thinking about other topological objects such as braids and tangles.In his later years Gauss held the emerging field of topology in a very high esteem and expected great future developments for it, but since there is so few written material by Gauss from this period, his influence was made mainly through occasional remarks and oral communications.", "For example, an indirect report by Mobius referred to a surface constructed by Gauss, which Gauss called \"double ring\" and sayed something about its connectivity properties.", "This report is consistent with a fragment of Gauss, written around 1840, which sketched a theory of the order of connectivity of surfaces.", "Finally, it is worth mentioning that in the introduction to Listing's book \"''Vorstudien zur Topologie''\" (1847), Listing expressed his indebtness to Gauss's influence.Gauss bust by Heinrich Hesemann (1855)=== Minor mathematical accomplishments ===Gauss's work did not only initiate significant mathematical theories, as he was also the author of many little \"gems\" in mathematics, especially in elementary geometry and algebra.", "In his way, he helped spread the new mathematical ideas of his time by demonstrating how they illuminate and shorten the solution of small mathematical problems.For example, he was a vivid spirit in applying complex numbers to various problems, and used them in his work on perspective and projective geometry: in a short 1836 note on \"Projections of the Cube\", he stated the fundamental theorem of axonometry, which tells how to represent a 3D cube on a 2D plane with complete accuracy, via complex numbers.", "In an unpublished 1819 note entitled \"the Sphere\", he conceived of the complex plane extended by a point at infinity as the stereographic projection of a sphere (the Riemann sphere), and described rotations of this sphere as the action of certain linear fractional transformations on the extended complex plane.Under the context of Gauss's heading of extended algebraic systems, it must be mentioned that there is solid evidence that he had in his foresight the algebraic system of quaternions, the discovery of the great William Rowan Hamilton.", "In 1819, Gauss drafted an unpublished short treatise on \"Rotations of Space\", in which he elaborated on the use of quadruples of real numbers (of which he called \"scales\") to describe 3D rotations.In elementary geometry, he contributed his solution to the problem of constructing the largest-area ellipse that can be inscribed in a given quadrilateral, which was published in 1810 as an addition to Schumacher's translation of Lazare Carnot's treatise ''Géométrie de position''.", "He discovered a surprising result about the computation of area of pentagons.", "He made many contributions to spherical geometry, and in this context solved some practical problems about navigation by stars.One of his most remarkable investigations was concerned with John Napier's \"Pentagramma mirificum\" - a certain spherical pentagram whose properties intrigued and occupied Gauss's mind for several decades.", "In his studies of the Pentagramma he approached it from various points of view, and gradually gained a full understanding of its geometric, algebraic and analytic aspects.", "In particular, in 1843 he stated and proved several theorems connecting elliptic functions, Napier spherical pentagons and Poncelet pentagons in the plane.=== Magnetism and telegraphy ======= Geomagnetism ====Gauss-Weber monument in GöttingenThe Gauss-Weber magnetometerGauss' interest in magnetism is obvious since the first decennium of the 19th century.", "Since 1826, when Alexander von Humboldt visited him in Göttingen, both scientists began intensive research on geomagnetism, partly independent, partly in productive cooperation.", "In 1828, Gauss was Humboldt's personal guest during the conference of the Society of German Natural Scientists and Physicians in Berlin, where he got acquaintance with the physicist Wilhelm Weber.When Weber got the chair for physics in Göttingen as successor of Johann Tobias Mayer by Gauss' recommendation in 1831, both of them started a fruitful collaboration, leading to a new knowledge of magnetism with a representation for the unit of magnetism in terms of mass, charge, and time.", "They founded the ''Magnetic Association'' (German: \"Magnetischer Verein\"), an international working group of several observatories, which supported measurements of Earth's magnetic field in many regions of the world with equal methods at arranged dates in the years 1836 to 1841.In 1836, Humboldt was helpful to organize the worldwide spread of observatories including the British dominions with a letter to the Duke of Sussex, then president of the Royal Society, wherein he asked for support for a program of global research based on Gauss' methods.", "Together with other instigators, this led to a global programm known as \"Magnetical crusade\" under directory of Edward Sabine.", "The dates, times, and intervalls of observations were determined in advance, the ''Göttingen mean time'' was used as standard.", "Finally 61 stations participated in this global program.", "Gauss and Weber founded a series for the publication of the results, six volumes were edited between 1837 and 1843.Weber's departure to Leipzig in 1843 as late effect of the Göttingen Seven affair marked the end of Magnetic Assiciation activity.Following Humboldt's example, Gauss ordered a magnetic observatory to be built in the garden of his observatory, but both scientists differed over instrumental equipment; Gauss preferred stationary instruments, which he thought to give more precise results, whereas Humboldt was accustomed to movable instruments.", "Gauss was interested in the temporal and spatial variation of magnetic declination, inclination, and intensity, but discriminated Humboldt's concept of magnetic intensity to the terms of \"horizontal\" and \"vertical\" intensity.", "Together with Weber, he developed methods of measuring the components of intensity of the magnetic field, and constructed a suitable magnetometer to measure ''absolute values'' of the strength of the Earth's magnetic field, not more relative ones that depended on the apparatus.", "The precision of the magnetometer was about ten times higher than of previous instruments.", "With this work, Gauss was the first one who derived a non-mechanical quantity by basic mechanical quantities.Gauss carried out a \"General Theory of Terrestrial Magnetism\" (1839), in what he believed to describe the nature of magnetic Force; following Felix Klein, this work is actually a presentation of observations by use of spherical harmonics rather than a physical theory.", "The theory predicted the existence of exactly two magnetic poles on the earth, thus Hansteen's idea of four magnetic poles became obsolete, and the data allowed to determine their location with rather good precision.", "In his \"General theorems concerning the attractive and repulsive forces acting in reciprocal proportions of quadratic distances\" (1840) Gauss gave the baseline of a theory of the magnetic potential, based on Lagrange, Laplace, and Poisson; it seems rather unlikely that he had knowledge of the previous works of George Green on this subject.", "However, Gauss could never give any reasons for magnetism, nor a theory of magnetism similar to Newton's work on gravitation, that enabled scientists to predict geomagnetic effects in the future.Gauss got a remarkable influence on the begin of geophysics in Russia, when Adolph Theodor Kupffer, one of his former students, founded a magnetic observatory in St. Petersburg, following the eample of the observatory in Götttingen, and similar Ivan Simonov in Kazan.==== Electromagnetism ====Town plan of Göttingen with course of the telegraphic connectionThe discoveries of Hans Christian Ørsted on electromagnetism and Michael Faraday on electromagnetic induction drew Gauss' attention to these matters.", "Gauss and Weber found the rules for branched electric circuits, later benamed as Kirchhoff's circuit laws, and made inquiries on electromagnetism.", "They constructed the first electromechanical telegraph in 1833, and Weber himself connected the observatory with the institute for physics in the town centre of Göttingen, but they did not care for any further development of this invention with regard to commercial purposes.Gauss's main theoretical interests in electromagnetism were reflected in his attempts to formulate quantitive laws governing electromagnetic induction.", "In his notebooks from these years, he recorded several innovative formulations; he discovered the idea of vector potential function (independently rediscovered by Franz Ernst Neumann in 1845), and in January 1835 he wrote down an \"induction law\" equivalent to Faraday's law, which stated that the electromotive force at a given point in space is equal to the instantaneous rate of change (with respect to time) of this function.In the same year Gauss had an insightful speculative thought, according to which electromagnetic interaction between two electric charges propagates in space in finite speed, in a manner similar to light, and that the magnitude of this interaction might depend on their relative velocity.", "In this way, he refuted the notion of immediate action at a distance.", "In unpublished fragments and in an 1845 letter to Weber, Gauss attempted to unite electricity and magnetism by forming a single expression for the interaction between two charges in relative motion, from which both Coulomb's law and the effects of magnetism could be derived.His unpublished insights in these directions eventually merged into the so-called Weber electrodynamics, a theory that became obsolete today due to some essential difficulties to reconcile it with the undisputed Maxwell's theory.", "In retrospect, despite its incorrectness, the Gauss-Weber theory contained some of the germs of later ideas, such as the existence of an electromagnetic field that is in some sense independent of its point sources (Faraday's view), as well as the notion of retarded potential.=== Optics ===Instrument maker Johann Georg Repsold in Hamburg asked Gauss in 1807 for help to construct an achromatic lens system.", "Based on Gauss' calculations, Repsold succeeded with a new objective in 1810.A main problem, among other difficulties, was the non precise knowledge of the refractive index and dispersion of the used glass types.", "In a short article from 1817 Gauss dealt with the problem of removal of chromatic aberration in double lenses, and made calculations about adjustments of the shape and coefficients of refraction required to minimize it.", "His work was noted by the optician Carl August von Steinheil, who in 1860 indroduced the achromatic Steinheil doublet, based in part on Gauss's calculations.", "Many results in geometrical optics are scattered in Gauss's correspondences and handnotes.", "In his influential ''Dioptrical Investigations'' (1840), Gauss gave the first systematic analysis on the formation of images under a paraxial approximation (Gaussian optics).", "Gauss demonstrated, that under a paraxial approximation an optical system can be characterized by its cardinal points, and he derived the Gaussian lens formula, applicable without restrictions in respect to the thickness of the lenses.=== Mechanics ===Gauss' first and last business in mechanics concerned the earth's rotation.", "When his university friend Benzenberg carried out experiments to determine the deviation of falling masses from the perpendicular in 1802, what today is known as an effect of the Coriolis force, he asked Gauss for a theory based calculation of the values for comparison with the experimental ones.", "Gauss elaborated a system of fundamental equations for the motion, and his results correspondent sufficiently with Benzenberg's data, who published Gauss' considerations as appendix to his book on falling experiments.After Foucault had demonstrated his pendulum in public in 1851, Gerling questioned Gauss for further explanations.", "This instigated Gauss to design a new apparatus for demonstration with a much shorter length of pendulum than Foucault's one.", "The oscillations were observed with a reading telescope, with a vertical scale and a mirror fastened at the pendulum; the time of oscillation was 3.1 seconds.", "It is described in the Gauss–Gerling correspondence, and Weber made some experiments with this obviously working apparatus in 1853, but no data were published.Gauss's principle of least constraint of 1829 was established as a general concept to overcome the division of mechanics into statics and dynamics, combining D'Alembert's principle with Lagrange's principle of Virtual Work, and showing analogies to the method of least squares.=== Metrology ===In 1828, Gauss was appointed to head of a Board for weights and measures of the Kingdom of Hanover.", "He provided the creation of standards of length and measures.", "Gauss himself took care of the time-consuming measures and gave detailed orders for the mechanical preparation.", "In his correspondence with Schumacher, who was also working on this matter, he described new ideas for scales of high precision.", "He gave his final reports on the Hanoveran foot and pound to the government in 1841.This work got more than regional importance by the order of a law of 1836, that connected the Hanoveran measures with the English ones." ], [ "Anecdotes", "Parochial registration of Gauss' christening on 4 May 1777 with later added birth dateSeveral stories of his early genius have been reported.", "Carl Friedrich Gauss' mother had never recorded the date of his birth, remembering only that he had been born on a Wednesday, eight days before the Feast of the Ascension, which occurs 39 days after Easter.", "Gauss later solved this puzzle about his birthdate in the context of finding the date of Easter, deriving methods to compute the date in both past and future years.", "Gauss felt sorry for his new born daughter Wilhelmine, because she was born on the leap day in 1808 and thus would celebrate her birthday only every four years.In his memorial on Gauss, Wolfgang Sartorius von Waltershausen tells a story about the three-years-aged Gauss, who corrected a math error his father made.", "The most popular story, also told by Sartorius, tells of a school exercise: the teacher, J.G.", "Büttner, and his assistant, Martin Bartels, ordered students to add an arithmetic series.", "Out of about a hundred pupils, Gauss was the first to solve the problem correctly by a significant margin.", "Although (or because) Sartorius gave no details, in the course of time many versions of this story have been created, with more and more details regarding the nature of the seriesthe most frequent being the classical problem of adding together all the integers from 1 to 100and the circumstances in the classroom.Gauss' favorite English author was Walter Scott, but when he sometimes read the words \"the moon rises broad in the nord west\", he was very amused.Gauss referred to mathematics as \"the queen of sciences\" and arithmetics as \"the queen of mathematics\", and supposedly once espoused a belief in the necessity of immediately understanding Euler's identity as a benchmark pursuant to becoming a first-class mathematician." ], [ "Honours and awards", "Copley Medal for Gauss (1838)The first membership of a scientific society was given to Gauss in 1802 by the Russian Academy of Sciences.", "Further memberships (corresponding, foreign or full) were from the Academy of Sciences in Göttingen (1802/ 1807), the French Academy of Sciences (1804/ 1820), the Royal Society of London (1804), the Royal Prussian Academy in Berlin (1810), the National Academy of Science in Verona (1810), the Royal Society of Edinburgh (1820), the Bavarian Academy of Sciences of Munich (1820), the Royal Danish Academy in Copenhagen (1821), the Royal Astronomical Society in London (1821), the Royal Swedish Academy of Sciences (1821), the American Academy of Arts and Sciences in Boston (1822), the Royal Bohemian Society of Sciences in Prague (1833), the Royal Academy of Science, Letters and Fine Arts of Belgium (1841/ 1845), the Royal Society of Sciences in Uppsala (1843), the Royal Irish Academy in Dublin (1843), the Royal Institute of the Netherlands (1845/ 1851), the Spanish Royal Academy of Sciences in Madrid (1850), the Russian Geographical Society (1851), the Imperial Academy of Sciences in Vienna (1848), the American Philosophical Society (1853), the Cambridge Philosophical Society, and the Royal Hollandish Society of Sciences in Haarlem.Gauss was an honorary member of the University of Kazan and of the Philosophy Faculty of the University of Prague since 1849.Gauss received the Lalande Prize from the French Academy of Science in 1809 for the theory of planets and the means of determining their orbits from only three observations, the Danish Academy of Science prize in 1823 for \"his study of angle-preserving maps\", and the Copley Medal from the Royal Society in 1838 for \"his inventions and mathematical researches in magnetism\".Gauss was appointed Knight of the French Legion of Honour in 1837 and was one of the first members of the Prussian Order Pour le Merite (Civil class) when it was established in 1842.Furthermore, he received the Order of the Crown of Westphalia (1810), the Danish Order of the Dannebrog (1817), the Hanoverian Royal Guelphic Order (1815), the Swedish Order of the Polar Star (1844), the Order of Henry the Lion (1849), and the Bavarian Maximilian Order for Science and Art (1853).The Kings of Hanover appointed him the honorary titles \"Hofrath\" (1816) and \"Geheimer Hofrath\" (1845).", "On the occasion of his golden doctor degree jubilee he got the honorary citizenship of both towns of Brunswick and Göttingen in 1849.Soon after his death a medal was issued by order of King George V of Hanover with the back side inscription : ''GEORGIVS V REX HANNOVERAE MATHEMATICORVM PRINCIPI'' and the circumscription : ''ACADEMIAE SVAE GEORGIAE AVGVSTAE DECORI AETERNO''.The ″Gauss-Gesellschaft Göttingen″ (''Gauss Society'') was founded in 1964 for researches on life and work of Carl Friedrich Gauss and related persons and edits the ″Mitteilungen der Gauss-Gesellschaft″ (''Communications of the Gauss Society'')." ], [ "Writings", "=== Mathematics and astronomy ===Brunswick (1880), made by Hermann Heinrich Howaldt, designed by Fritz Schaper* 1799: (Doctoral thesis on the fundamental theorem of algebra, University of Helmstedt) Original book* 1816: * 1816: * 1850: ** (German)* 1800: (Calculation of the date of Easter)* 1801: ** * 1802: (Calculation of the date of Pesach)* 1808: (Introduces Gauss's lemma, uses it in the third proof of quadratic reciprocity)* 1809: } Original book** * 1811: (Orbit of Pallas)* 1811: (Determination of the sign of the quadratic Gauss sum, uses this to give the fourth proof of quadratic reciprocity)* 1812: * 1815: * 1818: (Fifth and sixth proofs of quadratic reciprocity)* 1818: * 1821: * 1823: * 1825: (Prize winnig essay from 1822 on conformal mapping)* 1828: (Three essays concerning the calculation of probabilities as the basis of the Gaussian law of error propagation)** * 1828: ** * 1828: * 1832: (Introduces the Gaussian integers, states (without proof) the law of biquadratic reciprocity, proves the supplementary law for 1 + ''i'')* 1845: * 1847: * Original book** === Physics ===* 1804: * 1813: * 1817: * 1829: * 1832: * 1841: ** The Intensity of the Earth's Magnetic Force Reduced to Absolute Measurement.", "Translated by Susan P.", "Johnson.", "* 1836: * 1840: * 1843: ==== together with Wilhelm Weber ====* 1837–1839: * 1840–1843: * 1840: === Collected works ===* === Correspondence ===* (letters from December 1804 to August 1844)* (letters to Boguslawski from February 1835 to January 1848)* (letters from February 1802 to October 1826)* (letters from September 1797 to February 1853; added letters of other correspondents)* (letters from June 1810 to June 1854)* (letters from June 1810 to June 1854)* (letters from July 1807 to December 1854; added letters of other correspondents)* (letters from 1835 to 1843)* (letters from February 1799 to September 1800)* * (letters from January 1802 to October 1819)* (letters from January 1820 to May 1839; added letters of other correspondents)* ** Volumes 1+2 (letters from April 1808 to March 1836)** Volumes 3+4 (letters from March 1836 to April 1845)** Volumes 5+6 (letters from April 1845 to November 1850)* (letters from 1795 to 1815)File:Disqvisitiones-800.jpg|Title page of Gauss' magnum opus, ''Disquisitiones Arithmeticae'' (1801)File:Gauss-12.jpg|Title of Theorema arithmetici demonstratio nova (1808)File:Gauss-5.jpg|alt=Title page of an 1890 copy of Carl Gauss' \"Theoria Motus Corporum Coelestium in sectionibus conicis solem ambientium.", "\"|Title page of ''Theoria Motus Corporum Coelestium in sectionibus conicis solem ambientium'' (1809)File:Gauss-9.jpg|alt=Title page of an 1857 copy of \"Theory of the Motion of the Heavenly Bodies Moving about the Sun in Conic Sections: A Translation of Gauss' \"Theoria Motus,\" translated to English by Charles Henry Davis|Title page to the English Translation of ''Theoria Motus'' by Charles Henry Davis (1857)File:Gauss-2.jpg|alt=Title page of an 1833 copy of \"Intensitas vis Magneticae Terrestris ad Mensuram Absolutam Revocata.", "\"|Title page of ''Intensitas vis Magneticae Terrestris ad Mensuram Absolutam Revocata'' (1833)File:Gauss-16.jpg|Volume II of \"''Carl Friedrich Gauss Werke'',\" 1876The Göttingen Academy of Sciences and Humanities provides a complete collection of the yet known letters from and to Carl Friedrich Gauss that is accessible online.", "The literary estate is kept and provided by the Göttingen State and University Library.", "Written estate from Carl Friedrich Gauss and family members can also be found in the municipal archive of Brunswick." ], [ "Names and Commemorations", "* List of things named after Carl Friedrich Gauss" ], [ "References", "=== Notes ======Citations====== Sources ===* * * First edition: ** With a critical view on Dunnington's style and appraisals* * * * * ** * * * * * === Further reading ===* * * * * ==== fictional ====* **" ], [ "External links", "* * Publications of C. F. Gauss in Astrophysics Data System* * * * * * * ''Carl Friedrich Gauss – Spuren seines Lebens'' (Places used as points for triangulation)" ] ]
wikipedia
[ [ "Cornish language" ], [ "Introduction", "'''Cornish''' (Standard Written Form: or ; ) is a Southwestern Brittonic language of the Celtic language family.", "It is a revived language, having become extinct as a living community language in Cornwall at the end of the 18th century.", "However, knowledge of Cornish, including speaking ability to a certain extent, continued to be passed on within families and by individuals, and a revival began in the early 20th century.", "The language has a growing number of second-language speakers, and a very small number of families now raise children to speak revived Cornish as a first language.", "Cornish is currently recognised under the European Charter for Regional or Minority Languages, and the language is often described as an important part of Cornish identity, culture and heritage.Along with Welsh and Breton, Cornish is descended from the Common Brittonic language spoken throughout much of Great Britain before the English language came to dominate.", "For centuries, until it was pushed westwards by English, it was the main language of Cornwall, maintaining close links with its sister language Breton, with which it was mutually intelligible, perhaps even as long as Cornish continued to be spoken as a vernacular.", "Cornish continued to function as a common community language in parts of Cornwall until the mid 18th century.", "There is some evidence of knowledge of the language persisting into the 19th century, possibly almost overlapping the beginning of revival efforts.A process to revive the language began in the early 20th century, and in 2010, UNESCO announced that its former classification of the language as \"extinct\" was \"no longer accurate.\"", "Since the revival of the language, some Cornish textbooks and works of literature have been published, and an increasing number of people are studying the language.", "Recent developments include Cornish music, independent films, and children's books.", "A small number of people in Cornwall have been brought up to be bilingual native speakers, and the language is taught in schools and appears on street nameplates.", "The first Cornish-language day care opened in 2010." ], [ "Classification", "Cornish is a Southwestern Brittonic language, a branch of the Insular Celtic section of the Celtic language family, which is a sub-family of the Indo-European language family.", "Brittonic also includes Welsh, Breton, Cumbric and possibly Pictish, the last two of which are extinct.", "Scottish Gaelic, Irish and Manx are part of the separate Goidelic branch of Insular Celtic.Joseph Loth viewed Cornish and Breton as being two dialects of the same language, claiming that \"Middle Cornish is without doubt closer to Breton as a whole than the modern Breton dialect of Quiberon is to that of Saint-Pol-de-Léon .\"", "Also, Kenneth Jackson argued that it is almost certain that Cornish and Breton would have been mutually intelligible as long as Cornish was a living language, and that Cornish and Breton are especially closely related to each other and less closely related to Welsh." ], [ "History", "A map showing the westward decline of Cornish, 1300–1750Cornish evolved from the Common Brittonic spoken throughout Britain south of the Firth of Forth during the British Iron Age and Roman period.", "As a result of westward Anglo-Saxon expansion, the Britons of the southwest were separated from those in modern-day Wales and Cumbria, which Jackson links to the defeat of the Britons at the Battle of Deorham in about 577.The western dialects eventually evolved into modern Welsh and the now extinct Cumbric, while Southwestern Brittonic developed into Cornish and Breton, the latter as a result of emigration to parts of the continent, known as Brittany over the following centuries.=== Old Cornish ===The area controlled by the southwestern Britons was progressively reduced by the expansion of Wessex over the next few centuries.", "During the Old Cornish () period (800–1200), the Cornish-speaking area was largely coterminous with modern-day Cornwall, after the Saxons had taken over Devon in their south-westward advance, which probably was facilitated by a second migration wave to Brittany that resulted in the partial depopulation of Devon.The first page of , a 12th-century Latin-Cornish glossaryThe earliest written record of the Cornish language comes from this period: a 9th-century gloss in a Latin manuscript of by Boethius, which used the words .", "The phrase may mean \"it the mind hated the gloomy places\", or alternatively, as Andrew Breeze suggests, \"she hated the land\".", "Other sources from this period include the ''Saints' List'', a list of almost fifty Cornish saints, the Bodmin manumissions, which is a list of manumittors and slaves, the latter with mostly Cornish names, and, more substantially, a Latin-Cornish glossary (the or Cottonian Vocabulary), a Cornish translation of Ælfric of Eynsham's Latin-Old English Glossary, which is thematically arranged into several groups, such as the Genesis creation narrative, anatomy, church hierarchy, the family, names for various kinds of artisans and their tools, flora, fauna, and household items.", "The manuscript was widely thought to be in Old Welsh until the 18th century when it was identified as Cornish by Edward Lhuyd.", "Some Brittonic glosses in the 9th-century colloquy were once identified as Old Cornish, but they are more likely Old Welsh, possibly influenced by a Cornish scribe.", "No single phonological feature distinguishes Cornish from both Welsh and Breton until the beginning of the assibilation of dental stops in Cornish, which is not found before the second half of the eleventh century, and it is not always possible to distinguish Old Cornish, Old Breton, and Old Welsh orthographically.=== Middle Cornish ===The opening verses of , the first play of the (the of medieval Cornish literature), written by an unknown monk in the late 14th century (The life of St. Meriasek) (f.56v.)", "Middle Cornish Saint's PlayThe Cornish language continued to flourish well through the Middle Cornish () period (1200–1600), reaching a peak of about 39,000 speakers in the 13th century, after which the number started to decline.", "This period provided the bulk of traditional Cornish literature, and was used to reconstruct the language during its revival.", "Most important is the , a cycle of three mystery plays, , and .", "Together these provide about 8,734 lines of text.", "The three plays exhibit a mixture of English and Brittonic influences, and, like other Cornish literature, may have been written at Glasney College near Penryn.", "From this period also are the hagiographical dramas (''The Life of Meriasek'') and (''The Life of Ke''), both of which feature as an antagonist the villainous and tyrannical King Tewdar (or Teudar), a historical medieval king in Armorica and Cornwall, who, in these plays, has been interpreted as a lampoon of either of the Tudor kings Henry VII or Henry VIII.Others are the ''Charter Fragment'', the earliest known continuous text in the Cornish language, apparently part of a play about a medieval marriage, and (''The Passion of Our Lord''), a poem probably intended for personal worship, were written during this period, probably in the second half of the 14th century.", "Another important text, the , was realized to be Cornish in 1949, having previously been incorrectly classified as Welsh.", "It is the longest text in the traditional Cornish language, consisting of around 30,000 words of continuous prose.", "This text is a late 16th century translation of twelve of Bishop Bonner's thirteen homilies by a certain John Tregear, tentatively identified as a vicar of St Allen from Crowan, and has an additional catena, Sacrament an Alter, added later by his fellow priest, Thomas Stephyn.", "In the reign of Henry VIII, an account was given by Andrew Boorde in his 1542 .", "He states, \"\"When Parliament passed the Act of Uniformity 1549, which established the 1549 edition of the English Book of Common Prayer as the sole legal form of worship in England, including Cornwall, people in many areas of Cornwall did not speak or understand English.", "The passing of this Act was one of the causes of the Prayer Book Rebellion (which may also have been influenced by the retaliation of the English after the failed Cornish Rebellion of 1497), with \"the commoners of Devonshyre and Cornwall\" producing a manifesto demanding a return to the old religious services and included an article that concluded, \"and so we the Cornyshe men (whereof certen of us understande no Englysh) utterly refuse thys newe Englysh.\"", "In response to their articles, the government spokesman (either Philip Nichols or Nicholas Udall) wondered why they did not just ask the king for a version of the liturgy in their own language.", "Archbishop Thomas Cranmer asked why the Cornishmen should be offended by holding the service in English, when they had before held it in Latin, which even fewer of them could understand.", "Anthony Fletcher points out that this rebellion was primarily motivated by religious and economic, rather than linguistic, concerns.", "The rebellion prompted a heavy-handed response from the government, and 5,500 people died during the fighting and the rebellion's aftermath.", "Government officials then directed troops under the command of Sir Anthony Kingston to carry out pacification operations throughout the West Country.", "Kingston subsequently ordered the executions of numerous individuals suspected of involvement with the rebellion as part of the post-rebellion reprisals.The rebellion eventually proved a turning-point for the Cornish language, as the authorities came to associate it with sedition and \"backwardness\".", "This proved to be one of the reasons why the Book of Common Prayer was never translated into Cornish (unlike Welsh), as proposals to do so were suppressed in the rebellion's aftermath.", "The failure to translate the Book of Common Prayer into Cornish led to the language's rapid decline during the 16th and 17th centuries.", "Peter Berresford Ellis cites the years 1550–1650 as a century of immense damage for the language, and its decline can be traced to this period.", "In 1680 William Scawen wrote an essay describing 16 reasons for the decline of Cornish, among them the lack of a distinctive Cornish alphabet, the loss of contact between Cornwall and Brittany, the cessation of the miracle plays, loss of records in the Civil War, lack of a Cornish Bible and immigration to Cornwall.", "Mark Stoyle, however, has argued that the 'glotticide' of the Cornish language was mainly a result of the Cornish gentry adopting English to dissociate themselves from the reputation for disloyalty and rebellion associated with the Cornish language since the 1497 uprising.=== Late Cornish ===William Bodinar's letter, dated 3 July 1776By the middle of the 17th century, the language had retreated to Penwith and Kerrier, and transmission of the language to new generations had almost entirely ceased.", "In his ''Survey of Cornwall'', published in 1602, Richard Carew writes:Most of the inhabitants can speak no word of Cornish, but very few are ignorant of the English; and yet some so affect their own, as to a stranger they will not speak it; for if meeting them by chance, you inquire the way, or any such matter, your answer shall be, \",\" \"I will speak no Saxonage.", "\"The Late Cornish () period from 1600 to about 1800 has a less substantial body of literature than the Middle Cornish period, but the sources are more varied in nature, including songs, poems about fishing and curing pilchards, and various translations of verses from the Bible, the Ten Commandments, the Lord's Prayer and the Creed.", "Edward Lhuyd's ''Archaeologia Britannica'', which was mainly recorded in the field from native speakers in the early 1700s, and his unpublished field notebook are seen as important sources of Cornish vocabulary, some of which are not found in any other source.", "''Archaeologia Britannica'' also features a complete version of a traditional folk tale, ''John of Chyanhor'', a short story about a man from St Levan who goes far to the east seeking work, eventually returning home after three years to find that his wife has borne him a child during his absence.In 1776, William Bodinar, who describes himself as having learned Cornish from old fishermen when he was a boy, wrote a letter to Daines Barrington in Cornish, with an English translation, which was probably the last prose written in the traditional language.", "In his letter, he describes the sociolinguistics of the Cornish language at the time, stating that there are no more than four or five old people in his village who can still speak Cornish, concluding with the remark that Cornish is no longer known by young people.", "However, the last recorded traditional Cornish literature may have been the ''Cranken Rhyme'', a corrupted version of a verse or song published in the late 19th century by John Hobson Matthews, recorded orally by John Davey (or Davy) of Boswednack, of uncertain date but probably originally composed during the last years of the traditional language.", "Davey had traditional knowledge of at least some Cornish.", "John Kelynack (1796–1885), a fisherman of Newlyn, was sought by philologists for old Cornish words and technical phrases in the 19th century.=== Decline of Cornish speakers between 1300 and 1800 ===alt=A black and white engraving of a woman in 18th century clothing with a bonnet.", "Fish, a crab, a crustacean and a jug are belowIt is difficult to state with certainty when Cornish ceased to be spoken, due to the fact that its last speakers were of relatively low social class and that the definition of what constitutes \"a living language\" is not clear cut.", "Peter Pool argues that by 1800 nobody was using Cornish as a daily language and no evidence exists of anyone capable of conversing in the language at that date.", "However, passive speakers, semi-speakers and rememberers, who retain some competence in the language despite not being fluent nor using the language in daily life, generally survive even longer.The traditional view that Dolly Pentreath (1692–1777) was the last native speaker of Cornish has been challenged, and in the 18th and 19th centuries there was academic interest in the language and in attempting to find the last speaker of Cornish.", "It has been suggested that, whereas Pentreath was probably the last ''monolingual'' speaker, the last ''native'' speaker may have been John Davey of Zennor, who died in 1891.However, although it is clear Davey possessed some traditional knowledge in addition to having read books on Cornish, accounts differ of his competence in the language.", "Some contemporaries stated he was able to converse on certain topics in Cornish whereas others affirmed they had never heard him claim to be able to do so.", "Robert Morton Nance, who reworked and translated Davey's Cranken Rhyme, remarked, \"There can be no doubt, after the evidence of this rhyme, of what there was to lose by neglecting John Davey.", "\"The search for the last speaker is hampered by a lack of transcriptions or audio recordings, so that it is impossible to tell from this distance whether the language these people were reported to be speaking was Cornish, or English with a heavy Cornish substratum, nor what their level of fluency was.", "Nevertheless this academic interest, along with the beginning of the Celtic Revival in the late 19th century, provided the groundwork for a Cornish language revival movement.Notwithstanding the uncertainty over who was the last speaker of Cornish, researchers have posited the following numbers for the prevalence of the language between 1050 and 1800.YearArea whereCornishwas spoken(in km2)Totalpopulationof CornwallNumber ofCornishspeakers105016,00015,000111021,00020,000115028,00026,00012003,27035,00030,000125043,00034,00013002,78052,00038,000135048,00032,00014002,36055,00034,00014502,36062,00033,00015001,89069,00033,000155076,00030,00016001,40084,00022,000165091093,00014,0001700530106,0005,0001750160140,000 \"Very few\"18000192,0000=== Revived Cornish ===In 1904, the Celtic language scholar and Cornish cultural activist Henry Jenner published ''A Handbook of the Cornish Language''.", "The publication of this book is often considered to be the point at which the revival movement started.", "Jenner wrote about the Cornish language in 1905, \"one may fairly say that most of what there was of it has been preserved, and that it has been continuously preserved, for there has never been a time when there were not some Cornishmen who knew some Cornish.", "\"The revival focused on reconstructing and standardising the language, including coining new words for modern concepts, and creating educational material in order to teach Cornish to others.", "In 1929 Robert Morton Nance published his Unified Cornish () system, based on the Middle Cornish literature while extending the attested vocabulary with neologisms and forms based on Celtic roots also found in Breton and Welsh, publishing a dictionary in 1938.Nance's work became the basis of revived Cornish () for most of the 20th century.", "During the 1970s, criticism of Nance's system, including the inconsistent orthography and unpredictable correspondence between spelling and pronunciation, as well as on other grounds such as the archaic basis of Unified and a lack of emphasis on the spoken language, resulted in the creation of several rival systems.", "In the 1980s, Ken George published a new system, ('Common Cornish'), based on a reconstruction of the phonological system of Middle Cornish, but with an approximately morphophonemic orthography.", "It was subsequently adopted by the Cornish Language Board and was the written form used by a reported 54.5% of all Cornish language users according to a survey in 2008, but was heavily criticised for a variety of reasons by Jon Mills and Nicholas Williams, including making phonological distinctions that they state were not made in the traditional language 1500, failing to make distinctions that they believe ''were'' made in the traditional language at this time, and the use of an orthography that deviated too far from the traditional texts and Unified Cornish.", "Also during this period, Richard Gendall created his Modern Cornish system (also known as Revived Late Cornish), which used Late Cornish as a basis, and Nicholas Williams published a revised version of Unified; however neither of these systems gained the popularity of Unified or Kemmyn.The revival entered a period of factionalism and public disputes, with each orthography attempting to push the others aside.", "By the time that Cornish was recognised by the UK government under the European Charter for Regional or Minority Languages in 2002, it had become recognised that the existence of multiple orthographies was unsustainable with regards to using the language in education and public life, as none had achieved a wide consensus.", "A process of unification was set about which resulted in the creation of the public-body Cornish Language Partnership in 2005 and agreement on a Standard Written Form in 2008.In 2010 a new milestone was reached when UNESCO altered its classification of Cornish, stating that its previous label of \"extinct\" was no longer accurate." ], [ "Geographic distribution and number of speakers", "Cornish can be seen in many places in Cornwall; this sign is at Penzance railway station.Speakers of Cornish reside primarily in Cornwall, which has a population of 563,600 (2017 estimate).", "There are also some speakers living outside Cornwall, particularly in the countries of the Cornish diaspora, as well as in other Celtic nations.", "Estimates of the number of Cornish speakers vary according to the definition of a speaker, and is difficult to determine accurately due to the individualised nature of language take-up.", "Nevertheless, there is recognition that the number of Cornish speakers is growing.", "From before the 1980s to the end of the 20th century there was a sixfold increase in the number of speakers to around 300.One figure for the number of people who know a few basic words, such as knowing that \"Kernow\" means \"Cornwall\", was 300,000; the same survey gave the number of people able to have simple conversations as 3,000.The Cornish Language Strategy project commissioned research to provide quantitative and qualitative evidence for the number of Cornish speakers: due to the success of the revival project it was estimated that 2,000 people were fluent (surveyed in spring 2008), an increase from the estimated 300 people who spoke Cornish fluently suggested in a study by Kenneth MacKinnon in 2000.Jenefer Lowe of the Cornish Language Partnership said in an interview with the BBC in 2010 that there were around 300 fluent speakers.", "Bert Biscoe, a councillor and bard, in a statement to the ''Western Morning News'' in 2014 said there were \"several hundred fluent speakers\".", "Cornwall Council estimated in 2015 that there were 300–400 fluent speakers who used the language regularly, with 5,000 people having a basic conversational ability in the language.A report on the 2011 Census published in 2013 by the Office for National Statistics placed the number of speakers at somewhere between 325 and 625.In 2017 the ONS released data based on the 2011 Census that placed the number of speakers at 557 people in England and Wales who declared Cornish to be their main language, 464 of whom lived in Cornwall.", "The 2021 census listed the number of Cornish speakers at 563.A study that appeared in 2018 established the number of people in Cornwall with at least minimal skills in Cornish, such as the use of some words and phrases, to be more than 3,000, including around 500 estimated to be fluent.The Institute of Cornish Studies at the University of Exeter is working with the Cornish Language Partnership to study the Cornish language revival of the 20th century, including the growth in number of speakers." ], [ "Legal status and recognition", "The view from Carn Brea beacon () in Penwith (), near Crows-an-Wra (), looking towards the village of Treave () with Porthcurno () in the distance.", "The Cornish language has had substantial influence on Cornwall's toponymy and nomenclature.In 2002, Cornish was recognized by the UK government under Part II of the European Charter for Regional or Minority Languages.", "UNESCO's ''Atlas of World Languages'' classifies Cornish as \"critically endangered\".", "UNESCO has said that a previous classification of 'extinct' \"does not reflect the current situation for Cornish\" and is \"no longer accurate\".===Within the UK===Cornwall Council's policy is to support the language, in line with the European Charter.", "A motion was passed in November 2009 in which the council promoted the inclusion of Cornish, as appropriate and where possible, in council publications and on signs.", "This plan has drawn some criticism.", "In October 2015, Cornwall Council announced that staff would be encouraged to use \"basic words and phrases\" in Cornish when dealing with the public.", "In 2021 Cornwall Council prohibited a marriage ceremony from being conducted in Cornish as the Marriage Act 1949 only allowed for marriage ceremonies in English or Welsh.In 2014, the Cornish people were recognised by the UK Government as a national minority under the Framework Convention for the Protection of National Minorities.", "The FCNM provides certain rights and protections to a national minority with regard to their minority language.In 2016, British government funding for the Cornish language ceased, and responsibility transferred to Cornwall Council." ], [ "Orthography", "'''Old Cornish'''Until around the middle of the 11th century, Old Cornish scribes used a traditional spelling system shared with Old Breton and Old Welsh, based on the pronunciation of British Latin.", "By the time of the Vocabularium Cornicum, usually dated to around 1100, Old English spelling conventions, such as the use of thorn (Þ, þ) and eth (Ð, ð) for dental fricatives, and wynn (Ƿ, ƿ) for /w/, had come into use, allowing documents written at this time to be distinguished from Old Welsh, which rarely uses these characters, and Old Breton, which does not use them at all.", "Old Cornish features include using initial ⟨ch⟩, ⟨c⟩, or ⟨k⟩ for /k/, and, in internal and final position, ⟨p⟩, ⟨t⟩, ⟨c⟩, ⟨b⟩, ⟨d⟩, and ⟨g⟩ are generally used for the phonemes /b/, /d/, /ɡ/, /β/, /ð/, and /ɣ/ respectively, meaning that the results of Brittonic lenition are not usually apparent from the orthography at this time.", "'''Middle Cornish'''Middle Cornish orthography has a significant level of variation, and shows influence from Middle English spelling practices.", "Yogh (Ȝ ȝ) is used in certain Middle Cornish texts, where it is used to represent a variety of sounds, including the dental fricatives /θ/ and /ð/, a usage which is unique to Middle Cornish and is never found in Middle English.", "Middle Cornish scribes tend to use ⟨c⟩ for /k/ before back vowels, and ⟨k⟩ for /k/ before front vowels, though this is not always true, and this rule is less consistent in certain texts.", "Middle Cornish scribes almost universally use ⟨wh⟩ to represent /ʍ/ (or /hw/), as in Middle English.", "Middle Cornish, especially towards the end of this period, tends to use orthographic ⟨g⟩ and ⟨b⟩ in word-final position in stressed monosyllables, and ⟨k⟩ and ⟨p⟩ in word-final position in unstressed final syllables, to represent the reflexes of late Brittonic /ɡ/ and /b/, respectively.", "'''Late Cornish'''Written sources from this period are often spelled following English spelling conventions since many of the writers of the time had not been exposed to Middle Cornish texts or the Cornish orthography within them.", "Around 1700, Edward Lhuyd visited Cornwall, introducing his own partly phonetic orthography that he used in his , which was adopted by some local writers, leading to the use of some Lhuydian features such as the use of circumflexes to denote long vowels, ⟨k⟩ before front vowels, word-final ⟨i⟩, and the use of ⟨dh⟩ to represent the voiced dental fricative /ð/.", "'''Revived Cornish'''After the publication of Jenner's ''Handbook of the Cornish Language'', the earliest revivalists used Jenner's orthography, which was influenced by Lhuyd's system.", "This system was abandoned following the development by Nance of a \"unified spelling\", later known as Unified Cornish, a system based on a standardization of the orthography of the early Middle Cornish texts.", "Nance's system was used by almost all Revived Cornish speakers and writers until the 1970s.", "Criticism of Nance's system, particularly the relationship of spelling to sounds and the phonological basis of Unified Cornish, resulted in rival orthographies appearing by the early 1980s, including Gendal's Modern Cornish, based on Late Cornish native writers and Lhuyd, and Ken George's Kernewek Kemmyn, a mainly morphophonemic orthography based on George's reconstruction of Middle Cornish , which features a number of orthographic, and phonological, distinctions not found in Unified Cornish.", "Kernewek Kemmyn is characterised by the use of universal ⟨k⟩ for /k/ (instead of ⟨c⟩ before back vowels as in Unified); ⟨hw⟩ for /hw/, instead of ⟨wh⟩ as in Unified; and ⟨y⟩, ⟨oe⟩, and ⟨eu⟩ to represent the phonemes /ɪ/, /o/, and /œ/ respectively, which are not found in Unified Cornish.", "Criticism of all of these systems, especially Kernewek Kemmyn, by Nicolas Williams, resulted in the creation of Unified Cornish Revised, a modified version of Nance's orthography, featuring: an additional phoneme not distinguished by Nance, \"ö in German schön\", represented in the UCR orthography by ⟨ue⟩; replacement of ⟨y⟩ with ⟨e⟩ in many words; internal ⟨h⟩ rather than ⟨gh⟩; and use of final ⟨b⟩, ⟨g⟩, and ⟨dh⟩ in stressed monosyllables.", "A Standard Written Form, intended as a compromise orthography for official and educational purposes, was introduced in 2008, although a number of previous orthographic systems remain in use and, in response to the publication of the SWF, another new orthography, Kernowek Standard, was created, mainly by Nicholas Williams and Michael Everson, which is proposed as an amended version of the Standard Written Form." ], [ "Phonology", "The phonological system of Old Cornish, inherited from Proto-Southwestern Brittonic and originally differing little from Old Breton and Old Welsh, underwent various changes during its Middle and Late phases, eventually resulting in several characteristics not found in the other Brittonic languages.", "The first sound change to distinguish Cornish from both Breton and Welsh, the assibilation of the dental stops and in medial and final position, had begun by the time of the Vocabularium Cornicum, c. 1100 or earlier.", "This change, and the subsequent, or perhaps dialectical, palatalization (or occasional rhotacization in a few words) of these sounds, results in orthographic forms such as Middle Cornish 'father', Late Cornish (Welsh ), Middle Cornish 'believe', Late Cornish (Welsh ), and Middle Cornish 'leave', Late Cornish (Welsh ).", "A further characteristic sound change, pre-occlusion, occurred during the sixteenth century, resulting in the nasals and being realised as and respectively in stressed syllables, and giving Late Cornish forms such as 'head' (Welsh ) and 'crooked' (Welsh ).As a revitalised language, the phonology of contemporary spoken Cornish is based on a number of sources, including various reconstructions of the sound system of middle and early modern Cornish based on an analysis of internal evidence such as the orthography and rhyme used in the historical texts, comparison with the other Brittonic languages Breton and Welsh, and the work of the linguist Edward Lhuyd, who visited Cornwall in 1700 and recorded the language in a partly phonetic orthography." ], [ "Vocabulary", "Cornish is a Celtic language, and the majority of its vocabulary, when usage frequency is taken into account, at every documented stage of its history is inherited direct from Proto-Celtic, either through the ancestral Proto-Indo-European language, or through vocabulary borrowed from unknown substrate language(s) at some point in the development of the Celtic proto-language from PIE.", "Examples of the PIE > PCelt.", "development are various terms related to kinship and people, including 'mother', 'aunt, mother's sister', 'sister', 'son', 'man', 'person, human', and 'people', and words for parts of the body, including 'hand' and 'tooth'.", "Inherited adjectives with an Indo-European etymology include 'new', 'broad, wide', 'red', 'old', 'young', and 'alive, living'.Several Celtic or Brittonic words cannot be reconstructed to Proto-Indo-European, and are suggested to have been borrowed from unknown substrate language(s) at an early stage, such as Proto-Celtic or Proto-Brittonic.", "Proposed examples in Cornish include 'beer' and 'badger'.Other words in Cornish inherited direct from Proto-Celtic include a number of toponyms, for example 'hill', 'fort', and 'land', and a variety of animal names such as 'mouse', 'wether', 'pigs', and 'bull'.During the Roman occupation of Britain a large number (around 800) of Latin loan words entered the vocabulary of Common Brittonic, which subsequently developed in a similar way to the inherited lexicon.", "These include 'arm' (from British Latin ), 'net' (from ), and 'cheese' (from ).A substantial number of loan words from English and to a lesser extent French entered the Cornish language throughout its history.", "Whereas only 5% of the vocabulary of the Old Cornish Vocabularium Cornicum is thought to be borrowed from English, and only 10% of the lexicon of the early modern Cornish writer William Rowe, around 42% of the vocabulary of the whole Cornish corpus is estimated to be English loan words, without taking frequency into account.", "(However when frequency ''is'' taken into account this figure for the entire corpus drops to 8%.)", "The many English loanwords, some of which were sufficiently well assimilated to acquire native Cornish verbal or plural suffixes or be affected by the mutation system, include 'to read', 'to understand', 'way', 'boot' and 'art'.Many Cornish words, such as mining and fishing terms, are specific to the culture of Cornwall.", "Examples include 'mine waste' and 'to mend fishing nets'.", "and are different types of pastries.", "is a 'traditional Cornish dance get-together' and is a specific kind of ceremonial dance that takes place in Cornwall.", "Certain Cornish words may have several translation equivalents in English, so for instance may be translated into English as either 'book' or 'volume' and can mean either 'hand' or 'fist'.As in other Celtic languages, Cornish lacks a number of verbs commonly found in other languages, including modals and psych-verbs; examples are 'have', 'like', 'hate', 'prefer', 'must/have to' and 'make/compel to'.", "These functions are instead fulfilled by periphrastic constructions involving a verb and various prepositional phrases." ], [ "Grammar", "The grammar of Cornish shares with other Celtic languages a number of features which, while not unique, are unusual in an Indo-European context.", "The grammatical features most unfamiliar to English speakers of the language are the initial consonant mutations, the verb–subject–object word order, inflected prepositions, fronting of emphasised syntactic elements and the use of two different forms for 'to be'.=== Morphology ======= Mutations ====Cornish has initial consonant mutation: The first sound of a Cornish word may change according to grammatical context.", "As in Breton, there are four types of mutation in Cornish (compared with three in Welsh, two in Irish and Manx and one in Scottish Gaelic).", "These changes apply to only certain letters (sounds) in particular grammatical contexts, some of which are given below:*Lenition or \"soft\" mutation:**Feminine singular nouns are lenited after 'the':*** 'cat' > 'the cat'*Spirantization or \"aspirate\" mutation:**Nouns are spirantized after 'my':*** 'father' > 'my father'*Provection or \"hard\" mutation:**Verbs are provected after the verbal particle (approximately English \"-ing\"):*** 'see' > 'seeing'*Lenition followed by provection (usually), or \"mixed\" mutation:**Type 1 mixed mutation:***Occurs after the affirmative particle :**** > 'I see'**Type 2 mixed mutation:***Occurs after 2nd person singular infixed pronoun :**** 'hand' > 'in thy hand'==== Articles ====Cornish has no indefinite article.", "can either mean 'harbour' or 'a harbour'.", "In certain contexts, can be used, with the meaning 'a certain, a particular', e.g.", "'a certain harbour'.", "There is, however, a definite article 'the', which is used for all nouns regardless of their gender or number, e.g.", "'the harbour'.==== Nouns ====Cornish nouns belong to one of two grammatical genders, masculine and feminine, but are not inflected for case.", "Nouns may be singular or plural.", "Plurals can be formed in various ways, depending on the noun:*Vowel change:** 'hole' > 'holes'*Addition of a specific plural suffix:** 'angel' > 'angels'** 'father' > 'fathers'** 'peddler' > 'peddlers'*Suppletion:** 'man' > 'men, people'Some nouns are collective or mass nouns.", "Singulatives can be formed from collective nouns by the addition of the suffix ⫽-enn⫽ (SWF ''-en''):* 'grass' > 'a blade of grass'* 'willow-trees' > 'a willow tree'==== Verbs ====Verbs are conjugated for person, number, tense and mood.", "For example, the verbal noun 'see' has derived forms such as 1st person singular present indicative 'I see', 3rd person plural imperfect indicative 'they saw', and 2nd person singular imperative 'see!'", "Grammatical categories can be indicated either by inflection of the main verb, or by the use of auxiliary verbs such as 'be' or 'do'.==== Prepositions ====Cornish uses inflected (or conjugated) prepositions: Prepositions are inflected for person and number.", "For example, (with, by) has derived forms such as 'with me', 'with him', and 'with you (plural)'.=== Syntax ===Word order in Cornish is somewhat fluid and varies depending on several factors such as the intended element to be emphasised and whether a statement is negative or affirmative.", "In a study on Cornish word order in the play Bewnans Meriasek (), Ken George has argued that the most common word order in main clauses in Middle Cornish was, in affirmative statements, SVO, with the verb in the third person singular:When affirmative statements are in the less common VSO order, they usually begin with an adverb or other element, followed by an affirmative particle, with the verb inflected for person and tense:In negative statements, the order was usually VSO, with an initial negative particle and the verb conjugated for person and tense:A similar structure is used for questions:Elements can be fronted for emphasis:Sentences can also be constructed periphrastically using auxiliary verbs such as 'be, exist':As Cornish lacks verbs such as 'to have', possession can also be indicated in this way:Enquiring about possession is similar, using a different interrogative form of :Nouns usually precede the adjective, unlike in English:Some adjectives usually precede the noun, however:" ], [ "Culture", "Michael Joseph the Smith () mounted on the north side of Blackheath common, south east London, near the south entrance to Greenwich ParkThe Celtic Congress and Celtic League are groups that advocate cooperation amongst the Celtic Nations in order to protect and promote Celtic languages and cultures, thus working in the interests of the Cornish language.There have been films such as , some televised, made entirely, or significantly, in the language.", "Some businesses use Cornish names.Cornish has significantly and durably affected Cornwall's place-names as well as Cornish surnames and knowledge of the language helps the understanding of these ancient meanings.", "Cornish names are adopted for children, pets, houses and boats.There is Cornish literature, including spoken poetry and song, as well as traditional Cornish chants historically performed in marketplaces during religious holidays and public festivals and gatherings.There are periodicals solely in the language, such as the monthly , and .", "BBC Radio Cornwall has a news broadcast in Cornish and sometimes has other programmes and features for learners and enthusiasts.", "Local newspapers such as the ''Western Morning News'' have articles in Cornish, and newspapers such as ''The Packet'', ''The West Briton'', and ''The Cornishman'' have also been known to have Cornish features.", "There is an online radio and TV service in Cornish called , publishing a one-hour podcast each week, based on a magazine format.", "It includes music in Cornish as well as interviews and features.The language has financial sponsorship from sources including the Millennium Commission.", "A number of language organisations exist in Cornwall: (Our Language), the Cornish sub-group of the European Bureau for Lesser-Used Languages, , (the Cornish Language Board) and (the Cornish Language Fellowship).There are ceremonies, some ancient, some modern, that use the language or are entirely in the language.Welcome sign at Truro Cathedral in several languages, including Cornish=== Cultural events ===Though estimates of the number of Cornish speakers vary, there are thought to be around five hundred today.", "Currently Cornish is spoken at home, outside the home, in the workplace and at ritual ceremonies.", "Cornish is also being used in the arts.Cornwall has had cultural events associated with the language, including the international Celtic Media Festival, hosted in St Ives in 1997.The Old Cornwall Society has promoted the use of the language at events and meetings.", "Two examples of ceremonies that are performed in both the English and Cornish languages are Crying the Neck and the annual mid-summer bonfires.Since 1969, there have been three full performances of the Ordinalia, originally written in the Cornish language, the most recent of which took place at the plen-an-gwary in St Just in September 2021.While significantly adapted from the original, as well as using mostly English-speaking actors, the plays used sizable amounts of Cornish, including a character who spoke only in Cornish and another who spoke both English and Cornish.", "The event drew thousands over two weeks, also serving as a celebration of Celtic culture.", "The next production, scheduled for 2024, could, in theory, be entirely in Cornish, without English, if assisted by a professional linguist.Outside of Cornwall, efforts to revive the Cornish language and culture through community events are occurring in Australia.", "A biennial festival, Kernewek Lowender, takes place in South Australia, where both cultural displays and language lessons are offered.=== Study and teaching ===Cornish is taught in some schools; it was previously taught at degree level at the University of Wales, though the only existing course in the language at university level is as part of a course in Cornish studies at the University of Exeter.", "In March 2008 a course in the language was started as part of the Celtic Studies curriculum at the University of Vienna, Austria.The University of Cambridge offers courses in Cornish through its John Trim Resources Centre, which is part of the university's Language Centre.", "In addition, the Department of Anglo-Saxon, Norse and Celtic (which is part of the Faculty of English) also carries out research into the Cornish language.In 2015 a university-level course aiming at encouraging and supporting practitioners working with young children to introduce the Cornish language into their settings was launched.", "The ''Cornish Language Practice Project (Early Years)'' is a level 4 course approved by Plymouth University and run at Cornwall College.", "The course is not a Cornish-language course but students will be assessed on their ability to use the Cornish language constructively in their work with young children.", "The course will cover such topics as ''Understanding Bilingualism'', ''Creating Resources'' and ''Integrating Language and Play'', but the focus of the language provision will be on Cornish.", "A non-accredited specialist Cornish-language course has been developed to run alongside the level 4 course for those who prefer tutor support to learn the language or develop their skills for use with young children.Cornwall's first Cornish-language crèche, , was established in 2010 at Cornwall College, Camborne.", "The nursery teaches children aged between two and five years alongside their parents to ensure the language is also spoken in the home.A number of dictionaries are available in the various orthographies, including ''A Learners' Cornish Dictionary in the Standard Written Form'' by Steve Harris (ed.", "), by Ken George, by Nicholas Williams and ''A Practical Dictionary of Modern Cornish'' by Richard Gendall.", "Course books include the three-part series, , and , as well as the more recent and .", "Several online dictionaries are now available, including one organised by An Akademi Kernewek in SWF.Classes and conversation groups for adults are available at several locations in Cornwall as well as in London, Cardiff and Bristol.", "Since the onset of the COVID-19 pandemic a number of conversation groups entitled have been held online, advertised through Facebook and other media.", "A surge in interest, not just from people in Cornwall but from all over the world, has meant that extra classes have been organised.=== Cornish studies ===William Scawen produced a manuscript on the declining Cornish language that continually evolved until he died in 1689, aged 89.He was one of the first to realise the language was dying out and wrote detailed manuscripts which he started working on when he was 78.The only version that was ever published was a short first draft but the final version, which he worked on until his death, is a few hundred pages long.", "At the same time a group of scholars led by John Keigwin (nephew of William Scawen) of Mousehole tried to preserve and further the Cornish language and chose to write in Cornish.", "One of their number, Nicholas Boson, tells how he had been discouraged from using Cornish to servants by his mother.", "This group left behind a large number of translations of parts of the Bible, proverbs and songs.", "They were contacted by the Welsh linguist Edward Lhuyd, who came to Cornwall to study the language.Early Modern Cornish was the subject of a study published by Lhuyd in 1707, and differs from the medieval language in having a considerably simpler structure and grammar.", "Such differences included sound changes and more frequent use of auxiliary verbs.", "The medieval language also possessed two additional tenses for expressing past events and an extended set of possessive suffixes.John Whitaker, the Manchester-born rector of Ruan Lanihorne, studied the decline of the Cornish language.", "In his 1804 work ''the Ancient Cathedral of Cornwall'' he concluded that: \"The English Liturgy, was not desired by the Cornish, but forced upon them by the tyranny of England, at a time when the English language was yet unknown in Cornwall.", "This act of tyranny was at once gross barbarity to the Cornish people, and a death blow to the Cornish language.", "\"Robert Williams published the first comprehensive Cornish dictionary in 1865, the .", "As a result of the discovery of additional ancient Cornish manuscripts, 2000 new words were added to the vocabulary by Whitley Stokes in ''A Cornish Glossary''.", "William C. Borlase published ''Proverbs and Rhymes in Cornish'' in 1866 while ''A Glossary of Cornish Names'' was produced by John Bannister in the same year.", "Frederick Jago published his ''English–Cornish Dictionary'' in 1882.In 2002, the Cornish language gained new recognition because of the European Charter for Regional and Minority Languages.", "Conversely, along with government provision was the governmental basis of \"New Public Management\", measuring quantifiable results as means of determining effectiveness.", "This put enormous pressure on finding a single orthography that could be used in unison.", "The revival of Cornish required extensive rebuilding.", "The Cornish orthographies that were reconstructed may be considered versions of Cornish because they are not traditional sociolinguistic variations.", "In the middle-to-late twentieth century, the debate over Cornish orthographies angered more people because several language groups received public funding.", "This caused other groups to sense favouritism as playing a role in the debate.A governmental policymaking structure called New Public Management (NPM) has helped the Cornish language by managing public life of the Cornish language and people.", "In 2007, the Cornish Language Partnership MAGA represents separate divisions of government and their purpose is to further enhance the Cornish Language Developmental Plan.", "MAGA established an Ad-Hoc Group, which resulted in three orthographies being presented.", "The relations for the Ad-Hoc Group were to obtain consensus among the three orthographies and then develop a \"single written form\".", "The result was creating a new form of Cornish, which had to be natural for both new learners and skilled speakers.=== Literature ======= Recent Modern Cornish literature ====In 1981, the Breton library edited (Passion of our lord), a 15th-century Cornish poem.", "The first complete translation of the Bible into Cornish, translated from English, was published in 2011.Another Bible translation project translating from original languages is underway.", "The New Testament and Psalms were posted on-line on YouVersion (Bible.com) and Bibles.org in July 2014 by the Bible Society.A few small publishers produce books in Cornish which are stocked in some local bookshops, as well as in Cornish branches of Waterstones and WH Smith, although publications are becoming increasingly available on the Internet.", "Printed copies of these may also be found from Amazon.", "The Truro Waterstones hosts the annual literary awards, established by to recognise publications relating to Cornwall or in the Cornish language.", "In recent years, a number of Cornish translations of literature have been published, including ''Alice's Adventures in Wonderland'' (2009), ''Around the World in Eighty Days'' (2009), ''Treasure Island'' (2010), ''The Railway Children'' (2012), ''Hound of the Baskervilles'' (2012), ''The War of the Worlds'' (2012), ''The Wind in the Willows'' (2013), ''Three Men in a Boat'' (2013), ''Alice in Wonderland and Through the Looking-Glass'' (2014), and ''A Christmas Carol'' (which won the 2012 award for Cornish Language books), as well as original Cornish literature such as '''' (''The Lyonesse Stone'') by Craig Weatherhill.", "Literature aimed at children is also available, such as (''Where's Spot?", "''), (''The Beast of Bodmin Moor''), three ''Topsy and Tim'' titles, two ''Tintin'' titles and (''Briallen and the Alien''), which won the 2015 award for Cornish Language books for children.", "In 2014 , Nicholas Williams's translation of J. R. R. Tolkien's ''The Hobbit'', was published.", "is a monthly magazine published entirely in the Cornish language.", "Members contribute articles on various subjects.", "The magazine is produced by Graham Sandercock who has been its editor since 1976.=== Media ===In 1983 BBC Radio Cornwall started broadcasting around two minutes of Cornish every week.", "In 1987, however, they gave over 15 minutes of airtime on Sunday mornings for a programme called ('Holdall'), presented by John King, running until the early 1990s.", "It was eventually replaced with a five-minute news bulletin called ('The News').", "The bulletin was presented every Sunday evening for many years by Rod Lyon, then Elizabeth Stewart, and currently a team presents in rotation.", "Pirate FM ran short bulletins on Saturday lunchtimes from 1998 to 1999.In 2006, Matthew Clarke who had presented the Pirate FM bulletin, launched a web-streamed news bulletin called ('Weekly News'), which in 2008 was merged into a new weekly magazine podcast (RanG).Cornish television shows have included a 1982 series by Westward Television with each episode containing a three-minute lesson in Cornish.", ", an eight-episode series produced by Television South West and broadcast between June and July 1984, later on S4C from May to July 1985, and as a schools programme in 1986.Also by Television South West were two bilingual programmes on Cornish Culture called .In 2016 Kelly's Ice Cream of Bodmin introduced a light hearted television commercial in the Cornish language and this was repeated in 2017.The first episode from the third season of the US television program ''Deadwood'' features a conversation between miners, purportedly in the Cornish language, but really in Irish.", "One of the miners is then shot by thugs working for businessman George Hearst who justify the murder by saying, \"He come at me with his foreign gibberish.", "\"A number of Cornish language films have been made, including ''Hwerow Hweg'', a 2002 drama film written and directed by Hungarian film-maker Antal Kovacs and ''Trengellick Rising'', a short film written and directed by Guy Potter.Screen Cornwall works with Cornwall Council to commission a short film in the Cornish language each year, with their FilmK competition.", "Their website states \"FylmK is an annual contemporary Cornish language short film competition, producing an imaginative and engaging film, in any genre, from distinctive and exciting filmmakers\".A monthly half-hour online TV show began in 2017 called (The Month).", "It contained news items about cultural events and more mainstream news stories all through Cornish.", "It also ran a cookery segment called \"\" ('Esther's Kitchen').", "The program has been out of production since March 2023.=== Music ===English composer Peter Warlock wrote a Christmas carol in Cornish (setting words by Henry Jenner).", "The Cornish electronic musician Aphex Twin has used Cornish names for track titles, most notably on his ''Drukqs'' album.Several traditional Cornish folk songs have been collected and can be sung to various tunes.", "These include \"\", \"\", and \"\".In 2018, the singer Gwenno Saunders released an album in Cornish, entitled , saying: \"I speak Cornish with my son: if you're comfortable expressing yourself in a language, you want to share it.", "\"=== Place-names and surnames ===SWFThe Cornish language features in the toponymy of Cornwall, with a significant contrast between English place-names prevalent in eastern Cornwall and Cornish place-names to the west of the Camel-Fowey river valleys, where English place-names are much less common.", "Hundreds of Cornish family names have an etymology in the Cornish language, the majority of which are derived from Cornish place-names.", "Long before the agreement of the Standard Written Form of Cornish in the 21st century, Late Cornish orthography in the Early Modern period usually followed Welsh to English transliteration, phonetically rendering C for K, I for Y, U for W, and Z for S. This meant that place names were adopted into English with spellings such as 'Porthcurno' and 'Penzance'; they are written and in the Standard Written Form of Cornish, agreed upon in 2008.Likewise words such as ('island') can be found spelled as '''' as at Ince Castle.", "These apparent mistransliterations can, however, reveal an insight into how names and places were actually pronounced, explaining, for example, how anglicised is still pronounced ˈlansǝn with emphasis on the first element, perhaps from Cornish , though the ''Concise Oxford Dictionary of English Place-Names'' considers this unlikely.The following tables present some examples of Cornish place names and surnames and their anglicised versions: English (anglicised)place-name Cornish place-name Translation Truro Three Roads Mouth of Fal Dunes of Pleustri Head Holy i.e.", "Holy Headland Ford Red Camm (crooked) Hill Saint Ostel Abode of Monks Court of the Crossroads Land of St Stephen English (anglicised) surname Cornish surname Translation 'The White' 'The Smith' Either a dialectal variant of Hilary (from Latin ),or from the parish of , meaning 'swan river'.", "'New house' 'Easter/Passion' 'Cornwall' 'Beautiful' Possibly 'Homestead of the doctor' From , literally meaning 'feast-acre'.", "'Mean/Middle town'" ], [ "Samples", "From the Universal Declaration of Human Rights: Cornish Translation All human beings are born free and equal in dignity and rights.", "They are endowed with reason and conscience and should act towards one another in a spirit of brotherhood.From , the Cornish anthem: Cornish Translation Old land of our fathers, your children love you, Dear country of the west, what land is your equal?", "Over all the world, we are spread far and wide, But our love is for you.", "Cornwall, Cornwall, we love Cornwall; For as long as the sea is a wall around you We are one and all for Cornwall!From the wrestler's oath: Cornish Translation On my honour and the honour of my country, I swear to wrestle without treachery or brutality And in token of my sincerity I offer my hand to my opponent.", "In the words of my forefathers: \"Fair play is sweet play\"." ], [ "See also", "* Anglo-Cornish, the Cornish dialect of the English language* Bible translations into Cornish* Cornish literature* List of Celtic-language media* Languages in the United Kingdom* List of topics related to Cornwall* Language revival* The Cornish Language Council ()* Manx, another Celtic language subject to revival efforts* European Charter for Regional or Minority Languages* Irish language revival* Breton language" ], [ "References" ], [ "Bibliography", "* Bruch, Benjamin; Bock, Albert (2008) ''An Outline of the Standard Written Form of Cornish''.", "Cornish Language Partnership* Hodge, Pol (2001) ''Cornish Names''.", "Truro: Dyllansow Fentenwynn * Jago, F. W. P., ''A Cornish Dictionary'' (1887) English Cornish dictionary* Jenner, Henry, A Handbook of the Cornish language: Chiefly in its latest stages with some account of its history and literature (1904) * Ellis, Peter B.", "(1971) ''The Story of the Cornish Language''.", "32 p. Truro: Tor Mark Press* Ellis, Peter B.", "(1974) ''The Cornish Language and its Literature''.", "ix, 230 p. London: Routledge & Kegan Paul* Everson, Michael (2007) ''A Proposed Standard Written Form of Cornish''.", "Cornish Language Partnership Process* Ferdinand, Siarl (2013).", "Brief History of the Cornish language, its Revival and its Current Situation.", "''E-Keltoi'', Vol.", "2, 2 Dec pp.", "199–227 * Jackson, Kenneth (1953) ''Language and History in Early Britain: A chronological survey of the Brittonic languages, first to twelfth century a.D.'' Edinburgh Uuniverty Ppress; 2nd ed.", "Dublin: Four Courts Press (1994) has a new introduction by William Gillies* Norris, Edwin, Sketch of Cornish grammar (1859) * Sandercock, Graham (1996) ''A Very Brief History of the Cornish Language''.", "Hayle: * Stokes, Whitley, = The Creation of the World: A Cornish Mystery (1863)* Weatherhill, Craig (1995) ''Cornish Place Names & Language''.", "Wilmslow: Sigma Press (reissued in 1998, 2000 ; second revised edition 2007 )* Weatherhill, Craig (2009) ''Concise Dictionary of Cornish Place-names''; edited by Michael Everson.", "Westport, Co. Mayo: Evertype * Williams, G. P, The preverbal particle Re in Cornish (1908)" ], [ "External links", "* A Handbook of the Cornish Language, by Henry Jenner A Project Gutenberg eBook* Cornish Language Partnership website* Endangered Languages Project: Cornish* A Cornish Internet radio station in nascent state featuring weekly podcasts in Cornish* Spellyans – Standard Written Form Cornish discussion list* UdnFormScrefys' site for the proposed compromise orthography, Kernowek Standard* List of localised software in Cornish* – A Taste of Cornish – basic Cornish lessons hosted by BBC Cornwall* Cornish Language Fellowship* Lyver Pysadow Kemyn (1980) Portions of the Book of Common Prayer in Cornish* Cornish today by Kenneth MacKinnon – from the BBC* Bibel Kernewek Cornish Bible Translation Project* An Index to the Historical Place Names of Cornwall* A review of the Cornish revival* Cornish language Sayings and Phrases=== Dictionaries ===* Gerlyver kernewek (Cornish dictionary)* An English-Cornish Glossary in the Standard Written Form – Cornish Language Partnership* '': a Dictionary of the Ancient Celtic Language of Cornwall'' by Robert Williams, Llandovery, 1865." ] ]
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[ [ "Complexity theory" ], [ "Introduction", "'''Complexity theory''' may refer to:" ], [ "Science and technology", "* Computational complexity theory, a field in theoretical computer science and mathematics* Complex systems theory, the study of the complexity in context of complex systems* Assembly theory, a way of characterizing extraterrestrial molecular complexity to assess the probability of the presence of life" ], [ "Other uses", "* Complexity economics, the application of complexity theory to economics* Complexity theory and organizations, the application of complexity theory to strategy" ], [ "See also", "* Computational complexity* Complexity (disambiguation)* Systems theory* Complex adaptive system, a special case of complex systems* Complex network" ] ]
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[ [ "Charybdis" ], [ "Introduction", "'''Charybdis''' (; , ; , ) is a sea monster in Greek mythology.", "She, with the sea monster Scylla, appears as a challenge to epic characters such as Odysseus, Jason, and Aeneas.", "Scholarship locates her in the Strait of Messina.The idiom \"between Scylla and Charybdis\" has come to mean being forced to choose between two similarly dangerous situations." ], [ "Description", "The Strait of Messina, with Scylla (underlined in red) and Charybdis on the opposite shoresThe sea monster Charybdis was believed to live under a small rock on one side of a narrow channel.", "Opposite her was Scylla, another sea monster, that lived inside a much larger rock.", "The sides of the strait were within an arrow-shot of each other, and sailors attempting to avoid one of them would come in reach of the other.", "To be \"between Scylla and Charybdis\" therefore means to be presented with two opposite dangers, the task being to find a route that avoids both.", "Three times a day, Charybdis swallowed a huge amount of water, before belching it back out again, creating large whirlpools capable of dragging a ship underwater.", "In some variations of the story, Charybdis was simply a large whirlpool instead of a sea monster.Through the descriptions of Greek mythical chroniclers and Greek historians such as Thucydides, modern scholars generally agree that Charybdis was said to have been located in the Strait of Messina, off the coast of Sicily and opposite a rock on the mainland identified with Scylla.", "A whirlpool does exist there, caused by currents meeting, but it is dangerous only to small craft in extreme conditions." ], [ "Family", "Another myth makes Charybdis the daughter of Poseidon and Gaia and living as a loyal servant to her father.The narrowest point of Strait of Messina as seen from the village of Torre Faro" ], [ "Mythology", "=== Origin ===Charybdis aided her father Poseidon in his feud with her paternal uncle Zeus and, as such, helped him engulf lands and islands in water.", "Zeus, angry over the land she stole from him, sent her to the bottom of the sea with a thunderbolt; from the sea bed, she drank the water from the sea thrice a day, creating whirlpools.", "She lingered on a rock with Scylla facing her directly on another rock, making a strait.In some myths, Charybdis was a voracious woman who stole oxen from Heracles, and was hurled by the thunderbolt of Zeus into the sea, where she retained her voracious nature.===The ''Odyssey''===A 19th-century engraving of the Strait of Messina, the site associated with Scylla and Charybdis Odysseus faced both Charybdis and Scylla while rowing through a narrow channel.", "He ordered his men to avoid Charybdis, thus forcing them to pass near Scylla, which resulted in the deaths of six of his men.", "Later, stranded on a raft, Odysseus was swept back through the strait and passed near Charybdis.", "His raft was sucked into her maw, but he survived by clinging to a fig tree growing on a rock over her lair.", "On the next outflow of water, when his raft was expelled, Odysseus recovered it and paddled away safely.===Jason and the Argonauts===The Argonauts were able to avoid both dangers because Hera ordered the Nereid Thetis to guide them through the perilous passage.===The ''Aeneid''===In the ''Aeneid'', the Trojans are warned by Helenus of Scylla and Charybdis, and are advised to avoid them by sailing around Pachynus point (Cape Passero) rather than risk the strait.", "Later, however, they find themselves passing Etna, and have to row for their lives to escape Charybdis.===Aesop===Aristotle mentions in his ''Meteorologica'' that Aesop once teased a ferryman by telling him a myth concerning Charybdis.", "With one gulp of the sea, she brought the mountains to view; islands appeared after the next.", "The third is yet to come and will dry the sea altogether, thus depriving the ferryman of his livelihood." ], [ "See also", "*Icefalls" ], [ "Notes" ], [ "References", "*Apollonius Rhodius, ''Argonautica'' translated by Robert Cooper Seaton (1853-1915), R. C. Loeb Classical Library Volume 001.London, William Heinemann Ltd, 1912.Online version at the Topos Text Project.", "*Apollonius Rhodius, ''Argonautica''.", "George W. Mooney.", "London.", "Longmans, Green.", "1912.Greek text available at the Perseus Digital Library.", "*Homer, ''The Odyssey'' with an English Translation by A.T. Murray, PH.D. in two volumes.", "Cambridge, MA., Harvard University Press; London, William Heinemann, Ltd. 1919.. Online version at the Perseus Digital Library.", "Greek text available from the same website.", "*Maurus Servius Honoratus, ''In Vergilii carmina comentarii.", "Servii Grammatici qui feruntur in Vergilii carmina commentarii;'' recensuerunt Georgius Thilo et Hermannus Hagen.", "Georgius Thilo.", "Leipzig.", "B. G. Teubner.", "1881.Online version at the Perseus Digital Library." ], [ "Further reading", "*Smith, William; ''Dictionary of Greek and Roman Biography and Mythology'', London (1873).", "\"Scylla\" 1." ], [ "External links", "**" ] ]
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[ [ "Carbon monoxide" ], [ "Introduction", "'''Carbon monoxide''' (chemical formula '''CO''') is a poisonous, flammable gas that is colorless, odorless, tasteless, and slightly less dense than air.", "Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond.", "It is the simplest carbon oxide.", "In coordination complexes, the carbon monoxide ligand is called ''carbonyl''.", "It is a key ingredient in many processes in industrial chemistry.The most common source of carbon monoxide is the partial combustion of carbon-containing compounds.", "Numerous environmental and biological sources generate carbon monoxide.", "In industry, carbon monoxide is important in the production of many compounds, including drugs, fragrances, and fuels.", "Upon emission into the atmosphere, carbon monoxide affects several processes that contribute to climate change.Carbon monoxide has important biological roles across phylogenetic kingdoms.", "It is produced by many organisms, including humans.", "In mammalian physiology, carbon monoxide is a classical example of hormesis where low concentrations serve as an endogenous neurotransmitter (gasotransmitter) and high concentrations are toxic resulting in carbon monoxide poisoning.", "It is isoelectronic with cyanide anion CN−." ], [ "History", "=== Prehistory ===Humans have maintained a complex relationship with carbon monoxide since first learning to control fire circa 800,000 BC.", "Early humans probably discovered the toxicity of carbon monoxide poisoning upon introducing fire into their dwellings.", "The early development of metallurgy and smelting technologies emerging circa 6,000 BC through the Bronze Age likewise plagued humankind from carbon monoxide exposure.", "Apart from the toxicity of carbon monoxide, indigenous Native Americans may have experienced the neuroactive properties of carbon monoxide through shamanistic fireside rituals.=== Ancient history ===Early civilizations developed mythological tales to explain the origin of fire, such as Prometheus from Greek mythology who shared fire with humans.", "Aristotle (384–322 BC) first recorded that burning coals produced toxic fumes.", "Greek physician Galen (129–199 AD) speculated that there was a change in the composition of the air that caused harm when inhaled, and many others of the era developed a basis of knowledge about carbon monoxide in the context of coal fume toxicity.", "Cleopatra may have died from carbon monoxide poisoning.=== Pre-industrial revolution===Georg Ernst Stahl mentioned ''carbonarii halitus'' in 1697 in reference to toxic vapors thought to be carbon monoxide.", "Friedrich Hoffmann conducted the first modern scientific investigation into carbon monoxide poisoning from coal in 1716.Herman Boerhaave conducted the first scientific experiments on the effect of carbon monoxide (coal fumes) on animals in the 1730s.Joseph Priestley is considered to have first synthesized carbon monoxide in 1772.Carl Wilhelm Scheele similarly isolated carbon monoxide from charcoal in 1773 and thought it could be the carbonic entity making fumes toxic.", "Torbern Bergman isolated carbon monoxide from oxalic acid in 1775.Later in 1776, the French chemist produced CO by heating zinc oxide with coke, but mistakenly concluded that the gaseous product was hydrogen, as it burned with a blue flame.", "In the presence of oxygen, including atmospheric concentrations, carbon monoxide burns with a blue flame, producing carbon dioxide.", "Antoine Lavoisier conducted similar inconclusive experiments to Lassone in 1777.The gas was identified as a compound containing carbon and oxygen by William Cruickshank in 1800.Thomas Beddoes and James Watt recognized carbon monoxide (as hydrocarbonate) to brighten venous blood in 1793.Watt suggested coal fumes could act as an antidote to the oxygen in blood, and Beddoes and Watt likewise suggested hydrocarbonate has a greater affinity for animal fiber than oxygen in 1796.In 1854, Adrien Chenot similarly suggested carbon monoxide to remove the oxygen from blood and then be oxidized by the body to carbon dioxide.", "The mechanism for carbon monoxide poisoning is widely credited to Claude Bernard whose memoirs beginning in 1846 and published in 1857 phrased, \"prevents arterials blood from becoming venous\".", "Felix Hoppe-Seyler independently published similar conclusions in the following year.===Advent of industrial chemistry===Carbon monoxide gained recognition as an essential reagent in the 1900s.", "Three industrial processes illustrate its evolution in industry.", "In the Fischer–Tropsch process, coal and related carbon-rich feedstocks are converted into liquid fuels via the intermediacy of CO.", "Originally developed as part of the German war effort to compensate for their lack of domestic petroleum, this technology continues today.", "Also in Germany, a mixture of CO and hydrogen was found to combine with olefins to give aldehydes.", "This process, called hydroformylation, is used to produce many large scale chemicals such as surfactants as well as specialty compounds that are popular fragrances and drugs.", "For example, CO is used in the production of vitamin A.", "In a third major process, attributed to researchers at Monsanto, CO combines with methanol to give acetic acid.", "Most acetic acid is produced by the Cativa process.", "Hydroformylation and the acetic acid syntheses are two of myriad carbonylation processes." ], [ "Physical and chemical properties", "Carbon monoxide is the simplest oxocarbon and is isoelectronic with other triply-bonded diatomic species possessing 10 valence electrons, including the cyanide anion, the nitrosonium cation, boron monofluoride and molecular nitrogen.", "It has a molar mass of 28.0, which, according to the ideal gas law, makes it slightly less dense than air, whose average molar mass is 28.8.The carbon and oxygen are connected by a triple bond that consists of a net two pi bonds and one sigma bond.", "The bond length between the carbon atom and the oxygen atom is 112.8 pm.", "This bond length is consistent with a triple bond, as in molecular nitrogen (N2), which has a similar bond length (109.76 pm) and nearly the same molecular mass.", "Carbon–oxygen double bonds are significantly longer, 120.8 pm in formaldehyde, for example.", "The boiling point (82 K) and melting point (68 K) are very similar to those of N2 (77 K and 63 K, respectively).", "The bond-dissociation energy of 1072 kJ/mol is stronger than that of N2 (942 kJ/mol) and represents the strongest chemical bond known.The ground electronic state of carbon monoxide is a singlet state since there are no unpaired electrons.+Thermal and physical properties of carbon monoxide (CO) at atmospheric pressureTemperature (°C) Temperature (K) Density (kg/m3) Specific heat (J/g °C) Dynamic viscosity (cg/m s) Kinematic viscosity (cm2/s) Thermal conductivity (cW/m °C) Thermal diffusivity (cm2/s) Prandtl number -73.152001.6888 1.0451.270.07521.7 0.09630.781 -53.152201.5341 1.0441.370.08931.9 0.119 0.753 -33.152401.4055 1.0431.470.105 2.060.141 0.744 -13.152601.2967 1.0431.570.121 2.210.163 0.7416.852801.2038 1.0421.660.138 2.360.188 0.73326.853001.1233 1.0431.750.156 2.5 0.213 0.7346.853201.0529 1.0431.840.175 2.630.239 0.7366.853400.9909 1.0441.930.195 2.780.269 0.72586.853600.9357 1.0452.020.216 2.910.298 0.725106.853800.8864 1.0472.1 0.237 3.050.329 0.729126.854000.8421 1.0492.180.259 3.180.36 0.719176.854500.7483 1.0552.370.317 3.5 0.443 0.714226.855000.673521.0652.540.377 3.810.531 0.71276.855500.612261.0762.710.443 4.110.624 0.71326.856000.561261.0882.860.51 4.4 0.721 0.707376.856500.518061.1013.010.581 4.7 0.824 0.705426.857000.481021.1143.150.655 5 0.933 0.702476.857500.448991.1273.290.733 5.281.04 0.702526.858000.420951.14 3.430.815 5.551.16 0.705===Bonding and dipole moment===Carbon and oxygen together have a total of 10 electrons in the valence shell.", "Following the octet rule for both carbon and oxygen, the two atoms form a triple bond, with six shared electrons in three bonding molecular orbitals, rather than the usual double bond found in organic carbonyl compounds.", "Since four of the shared electrons come from the oxygen atom and only two from carbon, one bonding orbital is occupied by two electrons from oxygen, forming a dative or dipolar bond.", "This causes a C←O polarization of the molecule, with a small negative charge on carbon and a small positive charge on oxygen.", "The other two bonding orbitals are each occupied by one electron from carbon and one from oxygen, forming (polar) covalent bonds with a reverse C→O polarization since oxygen is more electronegative than carbon.", "In the free carbon monoxide molecule, a net negative charge δ– remains at the carbon end and the molecule has a small dipole moment of 0.122 D.The molecule is therefore asymmetric: oxygen has more electron density than carbon and is also slightly positively charged compared to carbon being negative.", "By contrast, the isoelectronic dinitrogen molecule has no dipole moment.The most important resonance form of carbon monoxide is –C≡O+.", "An important minor resonance contributor is the non-octet carbenic structure :C=O.Carbon monoxide has a computed fractional bond order of 2.6, indicating that the \"third\" bond is important but constitutes somewhat less than a full bond.", "Thus, in valence bond terms, –C≡O+ is the most important structure, while :C=O is non-octet, but has a neutral formal charge on each atom and represents the second most important resonance contributor.", "Because of the lone pair and divalence of carbon in this resonance structure, carbon monoxide is often considered to be an extraordinarily stabilized carbene.", "Isocyanides are compounds in which the O is replaced by an NR (R = alkyl or aryl) group and have a similar bonding scheme.If carbon monoxide acts as a ligand, the polarity of the dipole may reverse with a net negative charge on the oxygen end, depending on the structure of the coordination complex.See also the section ''\"Coordination chemistry\"'' below.===Bond polarity and oxidation state===Theoretical and experimental studies show that, despite the greater electronegativity of oxygen, the dipole moment points from the more-negative carbon end to the more-positive oxygen end.", "The three bonds are in fact polar covalent bonds that are strongly polarized.", "The calculated polarization toward the oxygen atom is 71% for the σ-bond and 77% for both π-bonds.The oxidation state of carbon in carbon monoxide is +2 in each of these structures.", "It is calculated by counting all the bonding electrons as belonging to the more electronegative oxygen.", "Only the two non-bonding electrons on carbon are assigned to carbon.", "In this count, carbon then has only two valence electrons in the molecule compared to four in the free atom." ], [ "Occurrence", "Monthly averages of global concentrations of tropospheric carbon monoxide at an altitude of about 12,000 feet.", "Data were collected by the MOPITT (Measurements Of Pollution In The Troposphere) sensor on NASA's Terra satellite.Carbon monoxide occurs in various natural and artificial environments.", "Photochemical degradation of plant matter for example generates an estimated 60 million tons/year.", "Typical concentrations in parts per million are as follows:+'''Composition of dry atmosphere, by volume''' Concentration (ppmv) Source 0.1 Natural atmosphere level (MOPITT) 0.5–5 Average level in homes 5–15 Near properly-adjusted gas stoves in homes, modern vehicle exhaust emissions 17 Atmosphere of Venus 100–200 Exhaust from automobiles in the Mexico City central area in 1975 700 Atmosphere of Mars 12 kilograms per year.", "Other natural sources of CO include volcanoes, forest and bushfires, and other miscellaneous forms of combustion such as fossil fuels.", "Small amounts are also emitted from the ocean, and from geological activity because carbon monoxide occurs dissolved in molten volcanic rock at high pressures in the Earth's mantle.", "Because natural sources of carbon monoxide vary from year to year, it is difficult to accurately measure natural emissions of the gas.Carbon monoxide has an indirect effect on radiative forcing by elevating concentrations of direct greenhouse gases, including methane and tropospheric ozone.", "CO can react chemically with other atmospheric constituents (primarily the hydroxyl radical, •OH) that would otherwise destroy methane.", "Through natural processes in the atmosphere, it is oxidized to carbon dioxide and ozone.", "Carbon monoxide is short-lived in the atmosphere (with an average lifetime of about one to two months), and spatially variable in concentration.Due to its long lifetime in the mid-troposphere, carbon monoxide is also used as a tracer for pollutant plumes.==== Pollution =========Urban pollution=====Carbon monoxide is a temporary atmospheric pollutant in some urban areas, chiefly from the exhaust of internal combustion engines (including vehicles, portable and back-up generators, lawnmowers, power washers, etc.", "), but also from incomplete combustion of various other fuels (including wood, coal, charcoal, oil, paraffin, propane, natural gas, and trash).Large CO pollution events can be observed from space over cities.======Role in ground level ozone formation======Carbon monoxide is, along with aldehydes, part of the series of cycles of chemical reactions that form photochemical smog.", "It reacts with hydroxyl radical (•OH) to produce a radical intermediate •HOCO, which transfers rapidly its radical hydrogen to O2 to form peroxy radical (HO2•) and carbon dioxide ().", "Peroxy radical subsequently reacts with nitrogen oxide (NO) to form nitrogen dioxide (NO2) and hydroxyl radical.", "NO2 gives O(3P) via photolysis, thereby forming O3 following reaction with O2.Since hydroxyl radical is formed during the formation of NO2, the balance of the sequence of chemical reactions starting with carbon monoxide and leading to the formation of ozone is::CO + 2O2 + hν → + O3(where hν refers to the photon of light absorbed by the NO2 molecule in the sequence)Although the creation of NO2 is the critical step leading to low level ozone formation, it also increases this ozone in another, somewhat mutually exclusive way, by reducing the quantity of NO that is available to react with ozone.=====Indoor pollution=====In closed environments, the concentration of carbon monoxide can rise to lethal levels.", "On average, 170 people in the United States die every year from carbon monoxide produced by non-automotive consumer products.These products include malfunctioning fuel-burning appliances such as furnaces, ranges, water heaters, and gas and kerosene room heaters; engine-powered equipment such as portable generators (and cars left running in attached garages); fireplaces; and charcoal that is burned in homes and other enclosed areas.", "Many deaths have occurred during power outages due to severe weather such as Hurricane Katrina and the 2021 Texas power crisis.=== Mining ===Miners refer to carbon monoxide as \"whitedamp\" or the \"silent killer\".", "It can be found in confined areas of poor ventilation in both surface mines and underground mines.", "The most common sources of carbon monoxide in mining operations are the internal combustion engine and explosives; however, in coal mines, carbon monoxide can also be found due to the low-temperature oxidation of coal.", "The idiom \"Canary in the coal mine\" pertained to an early warning of a carbon monoxide presence.=== Astronomy ===Beyond Earth, carbon monoxide is the second-most common diatomic molecule in the interstellar medium, after molecular hydrogen.", "Because of its asymmetry, this polar molecule produces far brighter spectral lines than the hydrogen molecule, making CO much easier to detect.", "Interstellar CO was first detected with radio telescopes in 1970.It is now the most commonly used tracer of molecular gas in general in the interstellar medium of galaxies, as molecular hydrogen can only be detected using ultraviolet light, which requires space telescopes.", "Carbon monoxide observations provide much of the information about the molecular clouds in which most stars form.Beta Pictoris, the second brightest star in the constellation Pictor, shows an excess of infrared emission compared to normal stars of its type, which is caused by large quantities of dust and gas (including carbon monoxide) near the star.In the atmosphere of Venus carbon monoxide occurs as a result of the photodissociation of carbon dioxide by electromagnetic radiation of wavelengths shorter than 169 nm.", "It has also been identified spectroscopically on the surface of Neptune's moon Triton.Solid carbon monoxide is a component of comets.", "The volatile or \"ice\" component of Halley's Comet is about 15% CO. At room temperature and at atmospheric pressure, carbon monoxide is actually only metastable (see Boudouard reaction) and the same is true at low temperatures where CO and are solid, but nevertheless it can exist for billions of years in comets.", "There is very little CO in the atmosphere of Pluto, which seems to have been formed from comets.", "This may be because there is (or was) liquid water inside Pluto.Carbon monoxide can react with water to form carbon dioxide and hydrogen::CO + H2O → + This is called the water-gas shift reaction when occurring in the gas phase, but it can also take place (very slowly) in an aqueous solution.If the hydrogen partial pressure is high enough (for instance in an underground sea), formic acid will be formed::CO + H2O → HCOOHThese reactions can take place in a few million years even at temperatures such as found on Pluto." ], [ "Chemistry", "Carbon monoxide has a wide range of functions across all disciplines of chemistry.", "The four premier categories of reactivity involve metal-carbonyl catalysis, radical chemistry, cation and anion chemistries.===Coordination chemistry===Energy level scheme of the σ and π orbitals of carbon monoxideHOMO of CO is a σ MO.LUMO of CO is a π* antibonding MO.Most metals form coordination complexes containing covalently attached carbon monoxide.", "Only metals in lower oxidation states will complex with carbon monoxide ligands.", "This is because there must be sufficient electron density to facilitate back-donation from the metal dxz-orbital, to the π* molecular orbital from CO.", "The lone pair on the carbon atom in CO also donates electron density to the dx2−y2 on the metal to form a sigma bond.", "This electron donation is also exhibited with the cis effect, or the labilization of CO ligands in the cis position.", "Nickel carbonyl, for example, forms by the direct combination of carbon monoxide and nickel metal:: Ni + 4 CO → Ni(CO)4 (1 bar, 55 °C)For this reason, nickel in any tubing or part must not come into prolonged contact with carbon monoxide.", "Nickel carbonyl decomposes readily back to Ni and CO upon contact with hot surfaces, and this method is used for the industrial purification of nickel in the Mond process.In nickel carbonyl and other carbonyls, the electron pair on the carbon interacts with the metal; the carbon monoxide donates the electron pair to the metal.", "In these situations, carbon monoxide is called the '''carbonyl''' ligand.", "One of the most important metal carbonyls is iron pentacarbonyl, Fe(CO)5:Structure of iron pentacarbonyl.Iron pentacarbonyl.Many metal–CO complexes are prepared by decarbonylation of organic solvents, not from CO. For instance, iridium trichloride and triphenylphosphine react in boiling 2-methoxyethanol or DMF to afford IrCl(CO)(PPh3)2.Metal carbonyls in coordination chemistry are usually studied using infrared spectroscopy.===Organic and main group chemistry===In the presence of strong acids and water, carbon monoxide reacts with alkenes to form carboxylic acids in a process known as the Koch–Haaf reaction.", "In the Gattermann–Koch reaction, arenes are converted to benzaldehyde derivatives in the presence of CO, AlCl3 and HCl.", "Organolithium compounds (e.g.", "butyl lithium) react with carbon monoxide, but these reactions have little scientific use.Although CO reacts with carbocations and carbanions, it is relatively nonreactive toward organic compounds without the intervention of metal catalysts.With main group reagents, CO undergoes several noteworthy reactions.", "Chlorination of CO is the industrial route to the important compound phosgene.", "With borane CO forms the adduct H3BCO, which is isoelectronic with the acetylium cation H3CCO+.", "CO reacts with sodium to give products resulting from C−C coupling such as sodium acetylenediolate 2·.", "It reacts with molten potassium to give a mixture of an organometallic compound, potassium acetylenediolate 2·, potassium benzenehexolate 6, and potassium rhodizonate 2·.The compounds cyclohexanehexone or triquinoyl (C6O6) and cyclopentanepentone or leuconic acid (C5O5), which so far have been obtained only in trace amounts, can be regarded as polymers of carbon monoxide.", "At pressures exceeding 5 GPa, carbon monoxide converts to polycarbonyl, a solid polymer that is metastable at atmospheric pressure but is explosive.==== Laboratory preparation ====Carbon monoxide is conveniently produced in the laboratory by the dehydration of formic acid or oxalic acid, for example with concentrated sulfuric acid.", "Another method is heating an intimate mixture of powdered zinc metal and calcium carbonate, which releases CO and leaves behind zinc oxide and calcium oxide::Zn + CaCO3 → ZnO + CaO + COSilver nitrate and iodoform also afford carbon monoxide::CHI3 + 3AgNO3 + H2O → 3HNO3 + CO + 3AgIFinally, metal oxalate salts release CO upon heating, leaving a carbonate as byproduct:: → +" ], [ "Production", "Thermal combustion is the most common source for carbon monoxide.", "Carbon monoxide is produced from the partial oxidation of carbon-containing compounds; it forms when there is not enough oxygen to produce carbon dioxide (), such as when operating a stove or an internal combustion engine in an enclosed space.A large quantity of CO byproduct is formed during the oxidative processes for the production of chemicals.", "For this reason, the process off-gases have to be purified.Many methods have been developed for carbon monoxide production.===Industrial production===A major industrial source of CO is producer gas, a mixture containing mostly carbon monoxide and nitrogen, formed by combustion of carbon in air at high temperature when there is an excess of carbon.", "In an oven, air is passed through a bed of coke.", "The initially produced equilibrates with the remaining hot carbon to give CO.", "The reaction of with carbon to give CO is described as the Boudouard reaction.", "Above 800 °C, CO is the predominant product:: (g) + C (s) → 2 CO (g) (Δ''H''r = 170 kJ/mol)Another source is \"water gas\", a mixture of hydrogen and carbon monoxide produced via the endothermic reaction of steam and carbon::H2O (g) + C (s) → H2 (g) + CO (g) (Δ''H''r = 131 kJ/mol)Other similar \"synthesis gases\" can be obtained from natural gas and other fuels.Carbon monoxide can also be produced by high-temperature electrolysis of carbon dioxide with solid oxide electrolyzer cells.", "One method developed at DTU Energy uses a cerium oxide catalyst and does not have any issues of fouling of the catalyst.", ":2 → 2 CO + O2Carbon monoxide is also a byproduct of the reduction of metal oxide ores with carbon, shown in a simplified form as follows::MO + C → M + COCarbon monoxide is also produced by the direct oxidation of carbon in a limited supply of oxygen or air.", ":2 C + O2 → 2 COSince CO is a gas, the reduction process can be driven by heating, exploiting the positive (favorable) entropy of reaction.", "The Ellingham diagram shows that CO formation is favored over in high temperatures." ], [ "Use", "===Chemical industry===Carbon monoxide is an industrial gas that has many applications in bulk chemicals manufacturing.", "Large quantities of aldehydes are produced by the hydroformylation reaction of alkenes, carbon monoxide, and H2.Hydroformylation is coupled to the Shell higher olefin process to give precursors to detergents.Phosgene, useful for preparing isocyanates, polycarbonates, and polyurethanes, is produced by passing purified carbon monoxide and chlorine gas through a bed of porous activated carbon, which serves as a catalyst.", "World production of this compound was estimated to be 2.74 million tonnes in 1989.:CO + Cl2 → COCl2Methanol is produced by the hydrogenation of carbon monoxide.", "In a related reaction, the hydrogenation of carbon monoxide is coupled to C−C bond formation, as in the Fischer–Tropsch process where carbon monoxide is hydrogenated to liquid hydrocarbon fuels.", "This technology allows coal or biomass to be converted to diesel.In the Cativa process, carbon monoxide and methanol react in the presence of a homogeneous iridium catalyst and hydroiodic acid to give acetic acid.", "This process is responsible for most of the industrial production of acetic acid.===Metallurgy===Carbon monoxide is a strong reductive agent and has been used in pyrometallurgy to reduce metals from ores since ancient times.", "Carbon monoxide strips oxygen off metal oxides, reducing them to pure metal in high temperatures, forming carbon dioxide in the process.", "Carbon monoxide is not usually supplied as is, in the gaseous phase, in the reactor, but rather it is formed in high temperature in presence of oxygen-carrying ore, or a carboniferous agent such as coke, and high temperature.", "The blast furnace process is a typical example of a process of reduction of metal from ore with carbon monoxide.Likewise, blast furnace gas collected at the top of blast furnace, still contains some 10% to 30% of carbon monoxide, and is used as fuel on Cowper stoves and on Siemens-Martin furnaces on open hearth steelmaking.===Lasers===Carbon monoxide has also been used as a lasing medium in high-powered infrared lasers.===Proposed use as fuel on Mars===Carbon monoxide has been proposed for use as a fuel on Mars.", "Carbon monoxide/oxygen engines have been suggested for early surface transportation use as both carbon monoxide and oxygen can be straightforwardly produced from the carbon dioxide atmosphere of Mars by zirconia electrolysis, without using any Martian water resources to obtain hydrogen, which would be needed to make methane or any hydrogen-based fuel." ], [ "Biological and physiological properties", "===Physiology===Carbon monoxide is a bioactive molecule which acts as a gaseous signaling molecule.", "It is naturally produced by many enzymatic and non-enzymatic pathways, the best understood of which is the catabolic action of heme oxygenase on the heme derived from hemoproteins such as hemoglobin.", "Following the first report that carbon monoxide is a normal neurotransmitter in 1993, carbon monoxide has received significant clinical attention as a biological regulator.Because of carbon monoxide's role in the body, abnormalities in its metabolism have been linked to a variety of diseases, including neurodegenerations, hypertension, heart failure, and pathological inflammation.", "In many tissues, carbon monoxide acts as anti-inflammatory, vasodilatory, and encouragers of neovascular growth.", "In animal model studies, carbon monoxide reduced the severity of experimentally induced bacterial sepsis, pancreatitis, hepatic ischemia/reperfusion injury, colitis, osteoarthritis, lung injury, lung transplantation rejection, and neuropathic pain while promoting skin wound healing.", "Therefore, there is significant interest in the therapeutic potential of carbon monoxide becoming pharmaceutical agent and clinical standard of care.====Medicine====Studies involving carbon monoxide have been conducted in many laboratories throughout the world for its anti-inflammatory and cytoprotective properties.", "These properties have the potential to be used to prevent the development of a series of pathological conditions including ischemia reperfusion injury, transplant rejection, atherosclerosis, severe sepsis, severe malaria, or autoimmunity.", "Many pharmaceutical drug delivery initiatives have developed methods to safely administer carbon monoxide, and subsequent controlled clinical trials have evaluated the therapeutic effect of carbon monoxide.===Microbiology===Microbiota may also utilize carbon monoxide as a gasotransmitter.", "Carbon monoxide sensing is a signaling pathway facilitated by proteins such as CooA.", "The scope of the biological roles for carbon monoxide sensing is still unknown.The human microbiome produces, consumes, and responds to carbon monoxide.", "For example, in certain bacteria, carbon monoxide is produced via the reduction of carbon dioxide by the enzyme carbon monoxide dehydrogenase with favorable bioenergetics to power downstream cellular operations.", "In another example, carbon monoxide is a nutrient for methanogenic archaea which reduce it to methane using hydrogen.Carbon monoxide has certain antimicrobial properties which have been studied to treat against infectious diseases.====Food science====Carbon monoxide is used in modified atmosphere packaging systems in the US, mainly with fresh meat products such as beef, pork, and fish to keep them looking fresh.", "The benefit is two-fold, carbon monoxide protects against microbial spoilage and it enhances the meat color for consumer appeal.", "The carbon monoxide combines with myoglobin to form carboxymyoglobin, a bright-cherry-red pigment.", "Carboxymyoglobin is more stable than the oxygenated form of myoglobin, oxymyoglobin, which can become oxidized to the brown pigment metmyoglobin.", "This stable red color can persist much longer than in normally packaged meat.", "Typical levels of carbon monoxide used in the facilities that use this process are between 0.4% and 0.5%.The technology was first given \"generally recognized as safe\" (GRAS) status by the U.S. Food and Drug Administration (FDA) in 2002 for use as a secondary packaging system, and does not require labeling.", "In 2004, the FDA approved CO as primary packaging method, declaring that CO does not mask spoilage odor.", "The process is currently unauthorized in many other countries, including Japan, Singapore, and the European Union.===Toxicity===Carbon monoxide poisoning is the most common type of fatal air poisoning in many countries.", "The Centers for Disease Control and Prevention estimates that several thousand people go to hospital emergency rooms every year to be treated for carbon monoxide poisoning.", "According to the Florida Department of Health, \"every year more than 500 Americans die from accidental exposure to carbon monoxide and thousands more across the U.S. require emergency medical care for non-fatal carbon monoxide poisoning.\"", "The American Association of Poison Control Centers (AAPCC) reported 15,769 cases of carbon monoxide poisoning resulting in 39 deaths in 2007.In 2005, the CPSC reported 94 generator-related carbon monoxide poisoning deaths.Carbon monoxide is colorless, odorless, and tasteless.", "As such, it is relatively undetectable.", "It readily combines with hemoglobin to produce carboxyhemoglobin which potentially affects gas exchange; therefore exposure can be highly toxic.", "Concentrations as low as 667 ppm may cause up to 50% of the body's hemoglobin to convert to carboxyhemoglobin.", "A level of 50% carboxyhemoglobin may result in seizure, coma, and fatality.", "In the United States, the OSHA limits long-term workplace exposure levels above 50 ppm.In addition to affecting oxygen delivery, carbon monoxide also binds to other hemoproteins such as myoglobin and mitochondrial cytochrome oxidase, metallic and non-metallic cellular targets to affect many cell operations.==== Weaponization ====In ancient history, Hannibal executed Roman prisoners with coal fumes during the Second Punic War.Carbon monoxide had been used for genocide during the Holocaust at some extermination camps, the most notable by gas vans in Chełmno, and in the Action T4 \"euthanasia\" program." ], [ "See also", "****Hydrocarbonate (gas)***Smoker's paradox* – hyperbaric treatment for CO poisoning* research articles on CO poisoning" ], [ "References" ], [ "External links", "* Global map of carbon monoxide distribution* Explanation of the structure* International Chemical Safety Card 0023* CDC NIOSH Pocket Guide to Chemical Hazards: Carbon monoxide—National Institute for Occupational Safety and Health (NIOSH), US Centers for Disease Control and Prevention (CDC)** Carbon Monoxide—NIOSH Workplace Safety and Health Topic—CDC** Carbon Monoxide Poisoning—Frequently Asked Questions—CDC* External MSDS data sheet* Carbon Monoxide Detector Placement* Microscale Gas Chemistry Experiments with Carbon Monoxide*" ] ]
wikipedia
[ [ "Conjecture" ], [ "Introduction", "The real part (red) and imaginary part (blue) of the Riemann zeta function along the critical line Re(''s'') = 1/2.The first non-trivial zeros can be seen at Im(''s'') = ±14.135, ±21.022 and ±25.011.The Riemann hypothesis, a famous conjecture, says that all non-trivial zeros of the zeta function lie along the critical line.In mathematics, a '''conjecture''' is a conclusion or a proposition that is proffered on a tentative basis without proof.", "Some conjectures, such as the Riemann hypothesis (still a conjecture) or Fermat's Last Theorem (a conjecture until proven in 1995 by Andrew Wiles), have shaped much of mathematical history as new areas of mathematics are developed in order to prove them." ], [ "Resolution of conjectures", "===Proof===Formal mathematics is based on ''provable'' truth.", "In mathematics, any number of cases supporting a universally quantified conjecture, no matter how large, is insufficient for establishing the conjecture's veracity, since a single counterexample could immediately bring down the conjecture.", "Mathematical journals sometimes publish the minor results of research teams having extended the search for a counterexample farther than previously done.", "For instance, the Collatz conjecture, which concerns whether or not certain sequences of integers terminate, has been tested for all integers up to 1.2 × 1012 (over a trillion).", "However, the failure to find a counterexample after extensive search does not constitute a proof that the conjecture is true—because the conjecture might be false but with a very large minimal counterexample.Nevertheless, mathematicians often regard a conjecture as strongly supported by evidence even though not yet proved.", "That evidence may be of various kinds, such as verification of consequences of it or strong interconnections with known results.A conjecture is considered proven only when it has been shown that it is logically impossible for it to be false.", "There are various methods of doing so; see methods of mathematical proof for more details.One method of proof, applicable when there are only a finite number of cases that could lead to counterexamples, is known as \"brute force\": in this approach, all possible cases are considered and shown not to give counterexamples.", "In some occasions, the number of cases is quite large, in which case a brute-force proof may require as a practical matter the use of a computer algorithm to check all the cases.", "For example, the validity of the 1976 and 1997 brute-force proofs of the four color theorem by computer was initially doubted, but was eventually confirmed in 2005 by theorem-proving software.When a conjecture has been proven, it is no longer a conjecture but a theorem.", "Many important theorems were once conjectures, such as the Geometrization theorem (which resolved the Poincaré conjecture), Fermat's Last Theorem, and others.===Disproof===Conjectures disproven through counterexample are sometimes referred to as ''false conjectures'' (cf.", "the Pólya conjecture and Euler's sum of powers conjecture).", "In the case of the latter, the first counterexample found for the n=4 case involved numbers in the millions, although it has been subsequently found that the minimal counterexample is actually smaller.===Independent conjectures===Not every conjecture ends up being proven true or false.", "The continuum hypothesis, which tries to ascertain the relative cardinality of certain infinite sets, was eventually shown to be independent from the generally accepted set of Zermelo–Fraenkel axioms of set theory.", "It is therefore possible to adopt this statement, or its negation, as a new axiom in a consistent manner (much as Euclid's parallel postulate can be taken either as true or false in an axiomatic system for geometry).In this case, if a proof uses this statement, researchers will often look for a new proof that ''doesn't'' require the hypothesis (in the same way that it is desirable that statements in Euclidean geometry be proved using only the axioms of neutral geometry, i.e.", "without the parallel postulate).", "The one major exception to this in practice is the axiom of choice, as the majority of researchers usually do not worry whether a result requires it—unless they are studying this axiom in particular." ], [ "Conditional proofs", "Sometimes, a conjecture is called a ''hypothesis'' when it is used frequently and repeatedly as an assumption in proofs of other results.", "For example, the Riemann hypothesis is a conjecture from number theory that — amongst other things — makes predictions about the distribution of prime numbers.", "Few number theorists doubt that the Riemann hypothesis is true.", "In fact, in anticipation of its eventual proof, some have even proceeded to develop further proofs which are contingent on the truth of this conjecture.", "These are called ''conditional proofs'': the conjectures assumed appear in the hypotheses of the theorem, for the time being.These \"proofs\", however, would fall apart if it turned out that the hypothesis was false, so there is considerable interest in verifying the truth or falsity of conjectures of this type." ], [ "Important examples", "===Fermat's Last Theorem===In number theory, Fermat's Last Theorem (sometimes called '''Fermat's conjecture''', especially in older texts) states that no three positive integers , '''', and '''' can satisfy the equation '''' for any integer value of '''' greater than two.This theorem was first conjectured by Pierre de Fermat in 1637 in the margin of a copy of ''Arithmetica'', where he claimed that he had a proof that was too large to fit in the margin.", "The first successful proof was released in 1994 by Andrew Wiles, and formally published in 1995, after 358 years of effort by mathematicians.", "The unsolved problem stimulated the development of algebraic number theory in the 19th century, and the proof of the modularity theorem in the 20th century.", "It is among the most notable theorems in the history of mathematics, and prior to its proof it was in the ''Guinness Book of World Records'' for \"most difficult mathematical problems\".===Four color theorem===A four-coloring of a map of the states of the United States (ignoring lakes).In mathematics, the four color theorem, or the four color map theorem, states that given any separation of a plane into contiguous regions, producing a figure called a ''map'', no more than four colors are required to color the regions of the map—so that no two adjacent regions have the same color.", "Two regions are called ''adjacent'' if they share a common boundary that is not a corner, where corners are the points shared by three or more regions.", "For example, in the map of the United States of America, Utah and Arizona are adjacent, but Utah and New Mexico, which only share a point that also belongs to Arizona and Colorado, are not.Möbius mentioned the problem in his lectures as early as 1840.The conjecture was first proposed on October 23, 1852 when Francis Guthrie, while trying to color the map of counties of England, noticed that only four different colors were needed.", "The five color theorem, which has a short elementary proof, states that five colors suffice to color a map and was proven in the late 19th century; however, proving that four colors suffice turned out to be significantly harder.", "A number of false proofs and false counterexamples have appeared since the first statement of the four color theorem in 1852.The four color theorem was ultimately proven in 1976 by Kenneth Appel and Wolfgang Haken.", "It was the first major theorem to be proved using a computer.", "Appel and Haken's approach started by showing that there is a particular set of 1,936 maps, each of which cannot be part of a smallest-sized counterexample to the four color theorem (i.e., if they did appear, one could make a smaller counter-example).", "Appel and Haken used a special-purpose computer program to confirm that each of these maps had this property.", "Additionally, any map that could potentially be a counterexample must have a portion that looks like one of these 1,936 maps.", "Showing this with hundreds of pages of hand analysis, Appel and Haken concluded that no smallest counterexample exists because any must contain, yet do not contain, one of these 1,936 maps.", "This contradiction means there are no counterexamples at all and that the theorem is therefore true.", "Initially, their proof was not accepted by mathematicians at all because the computer-assisted proof was infeasible for a human to check by hand.", "However, the proof has since then gained wider acceptance, although doubts still remain.===Hauptvermutung===The Hauptvermutung (German for main conjecture) of geometric topology is the conjecture that any two triangulations of a triangulable space have a common refinement, a single triangulation that is a subdivision of both of them.", "It was originally formulated in 1908, by Steinitz and Tietze.This conjecture is now known to be false.", "The non-manifold version was disproved by John Milnor in 1961 using Reidemeister torsion.The manifold version is true in dimensions .", "The cases were proved by Tibor Radó and Edwin E. Moise in the 1920s and 1950s, respectively.===Weil conjectures===In mathematics, the Weil conjectures were some highly influential proposals by on the generating functions (known as local zeta-functions) derived from counting the number of points on algebraic varieties over finite fields.A variety ''V'' over a finite field with ''q'' elements has a finite number of rational points, as well as points over every finite field with ''q''''k'' elements containing that field.", "The generating function has coefficients derived from the numbers ''N''''k'' of points over the (essentially unique) field with ''q''''k'' elements.Weil conjectured that such ''zeta-functions'' should be rational functions, should satisfy a form of functional equation, and should have their zeroes in restricted places.", "The last two parts were quite consciously modeled on the Riemann zeta function and Riemann hypothesis.", "The rationality was proved by , the functional equation by , and the analogue of the Riemann hypothesis was proved by .===Poincaré conjecture=== In mathematics, the Poincaré conjecture is a theorem about the characterization of the 3-sphere, which is the hypersphere that bounds the unit ball in four-dimensional space.", "The conjecture states that: An equivalent form of the conjecture involves a coarser form of equivalence than homeomorphism called homotopy equivalence: if a 3-manifold is ''homotopy equivalent'' to the 3-sphere, then it is necessarily ''homeomorphic'' to it.Originally conjectured by Henri Poincaré in 1904, the theorem concerns a space that locally looks like ordinary three-dimensional space but is connected, finite in size, and lacks any boundary (a closed 3-manifold).", "The Poincaré conjecture claims that if such a space has the additional property that each loop in the space can be continuously tightened to a point, then it is necessarily a three-dimensional sphere.", "An analogous result has been known in higher dimensions for some time.After nearly a century of effort by mathematicians, Grigori Perelman presented a proof of the conjecture in three papers made available in 2002 and 2003 on arXiv.", "The proof followed on from the program of Richard S. Hamilton to use the Ricci flow to attempt to solve the problem.", "Hamilton later introduced a modification of the standard Ricci flow, called ''Ricci flow with surgery'' to systematically excise singular regions as they develop, in a controlled way, but was unable to prove this method \"converged\" in three dimensions.", "Perelman completed this portion of the proof.", "Several teams of mathematicians have verified that Perelman's proof is correct.The Poincaré conjecture, before being proven, was one of the most important open questions in topology.===Riemann hypothesis===In mathematics, the Riemann hypothesis, proposed by , is a conjecture that the non-trivial zeros of the Riemann zeta function all have real part 1/2.The name is also used for some closely related analogues, such as the Riemann hypothesis for curves over finite fields.The Riemann hypothesis implies results about the distribution of prime numbers.", "Along with suitable generalizations, some mathematicians consider it the most important unresolved problem in pure mathematics.", "The Riemann hypothesis, along with the Goldbach conjecture, is part of Hilbert's eighth problem in David Hilbert's list of 23 unsolved problems; it is also one of the Clay Mathematics Institute Millennium Prize Problems.===P versus NP problem===The P versus NP problem is a major unsolved problem in computer science.", "Informally, it asks whether every problem whose solution can be quickly verified by a computer can also be quickly solved by a computer; it is widely conjectured that the answer is no.", "It was essentially first mentioned in a 1956 letter written by Kurt Gödel to John von Neumann.", "Gödel asked whether a certain NP-complete problem could be solved in quadratic or linear time.", "The precise statement of the P=NP problem was introduced in 1971 by Stephen Cook in his seminal paper \"The complexity of theorem proving procedures\" and is considered by many to be the most important open problem in the field.", "It is one of the seven Millennium Prize Problems selected by the Clay Mathematics Institute to carry a US$1,000,000 prize for the first correct solution.===Other conjectures===* Goldbach's conjecture* The twin prime conjecture* The Collatz conjecture* The Manin conjecture* The Maldacena conjecture* The Euler conjecture, proposed by Euler in the 18th century but for which counterexamples for a number of exponents (starting with n=4) were found beginning in the mid 20th century* The Hardy-Littlewood conjectures are a pair of conjectures concerning the distribution of prime numbers, the first of which expands upon the aforementioned twin prime conjecture.", "Neither one has either been proven or disproven, but it ''has'' been proven that both cannot simultaneously be true (i.e., at least one must be false).", "It has not been proven which one is false, but it is widely believed that the first conjecture is true and the second one is false.", "* The Langlands program is a far-reaching web of these ideas of 'unifying conjectures' that link different subfields of mathematics (e.g.", "between number theory and representation theory of Lie groups).", "Some of these conjectures have since been proved." ], [ "In other sciences", "Karl Popper pioneered the use of the term \"conjecture\" in scientific philosophy.", "Conjecture is related to hypothesis, which in science refers to a testable conjecture." ], [ "See also", "* Bold hypothesis* Futures studies* Hypotheticals* List of conjectures* Ramanujan machine" ], [ "References", "===Works cited===***" ], [ "External links", "** Open Problem Garden* Unsolved Problems web site" ] ]
wikipedia
[ [ "Christoph Ludwig Agricola" ], [ "Introduction", "'''Christoph Ludwig Agricola''' (5 November 1665 – 8 August 1724) was a German landscape painter and etcher.", "He was born and died at Regensburg (Ratisbon)." ], [ "Life and career", "Christoph Ludwig Agricola was born on 5 November 1665 at Regensburg in Germany.", "He trained, as many painters of the period did, by studying nature.He spent a great part of his life in travel, visiting England, the Netherlands and France, and residing for a considerable period at Naples, where he may have been influenced by Nicolas Poussin.", "He also stayed for some years circa 1712 in Venice, where he painted many works for the patron Zaccaria Sagredo.He died in Regensburg in 1724." ], [ "Work", "Although he primarily worked in gouache and oils, documentary sources reveal that he also produced a small number of etchings.", "He was a good draughtsman, used warm lighting and exhibited a warm, masterly brushstroke.His numerous landscapes, chiefly cabinet pictures, are remarkable for fidelity to nature, and especially for their skilful representation of varied phases of climate, especially nocturnal scenes and weather anomalies such as thunderstorms.", "In composition his style shows the influence of Nicolas Poussin and his work often displays the idealistic scenes associated with Poussin.", "In light and colour he imitates Claude Lorrain.", "His compositions include ruins of ancient buildings in the foreground, but his favourite figure for the foreground was men dressed in Oriental attire.", "He also produced a series of etchings of birds.His pictures can be found in Dresden, Braunschweig, Vienna, Florence, Naples and many other towns of both Germany and Italy." ], [ "Legacy", "He probably tutored the artist, Johann Theile, and had an enormous influence on him.", "Art historians have also noted that the work of the landscape painter, Christian Johann Bendeler (1699–1728), was also influenced by Agricola." ], [ "Gallery", "File:Christoph Ludwig Agricola (zugeschr.)", "- Eine Flusslandschaft mit Anglern.jpg|''River landscape''File:Christoph Ludwig Agricola - Großer Hänfling und Schopfmeise.jpg|''Greater Redpole and crested titmous; Bluethroat''File:Christoph Ludwig Agricola (Umkreis) - Räuber schießen auf Reisende.jpg|''Bandits Shooting at Travellers''File:Christoph Ludwig Agricola - Trappe un Elster in exotischer Landschaft.jpg|''A bustard and a magpie in an exotic landscape''File:Christoph Ludwig Agricola - Ein Vogel auf einem Ast.jpg|''A bird seated on a branch''File:Wintergezicht met ijsvermaak, RP-T-1898-A-3549.jpg|''Winter face with ice entertainment''File:Christoph Ludwig Agricola - Singvogel auf einem Nadelbaum.jpg|''Songbird in an Evergreen''" ], [ "References" ], [ "Further reading", "*" ] ]
wikipedia
[ [ "Claudius" ], [ "Introduction", "'''Tiberius Claudius Caesar Augustus Germanicus''' (; ; 1 August 10 BC – 13 October AD 54) was Roman emperor, ruling from AD 41 to 54.A member of the Julio-Claudian dynasty, Claudius was born to Drusus and Antonia Minor at Lugdunum in Roman Gaul, where his father was stationed as a military legate.", "He was the first Roman emperor to be born outside Italy.As he had a limp and slight deafness due to sickness at a young age, he was ostracized by his family and was excluded from public office until his consulship (which was shared with his nephew, Caligula, in 37).", "Claudius's infirmity probably saved him from the fate of many other nobles during the purges throughout the reigns of Tiberius and Caligula, as potential enemies did not see him as a serious threat.", "His survival led to his being declared emperor by the Praetorian Guard after Caligula's assassination, at which point he was the last adult male of his family.Despite his lack of experience, Claudius was an able and efficient administrator.", "He expanded the imperial bureaucracy to include freedmen, and helped restore the empire's finances after the excesses of Caligula's reign.", "He was also an ambitious builder, constructing new roads, aqueducts, and canals across the Empire.", "During his reign, the Empire started its successful conquest of Britain.", "Having a personal interest in law, he presided at public trials, and issued edicts daily.", "He was seen as vulnerable throughout his reign, particularly by elements of the nobility.", "Claudius was constantly forced to shore up his position, which resulted in the deaths of many senators.", "Those events damaged his reputation among the ancient writers, though more recent historians have revised that opinion.", "Many authors contend that he was murdered by his own wife, Agrippina the Younger.", "After his death at the age of 63, his grandnephew and legally adopted step-son, Nero, succeeded him as emperor." ], [ "Family and youth", "=== Early life ===Bust of Claudius's mother, Antonia MinorClaudius was born on 1 August 10 BC at Lugdunum (modern Lyon, France).", "He had two older siblings, Germanicus and Livilla.", "His mother, Antonia Minor, may have had two other children who died young.", "Claudius's maternal grandparents were Mark Antony and Octavia Minor, Augustus's sister, and he was therefore the great-great-grandnephew of Gaius Julius Caesar.", "His paternal grandparents were Livia, Augustus's third wife, and Tiberius Claudius Nero.", "During his reign, Claudius revived the rumor that his father Nero Claudius Drusus was actually the illegitimate son of Augustus, to give the appearance that Augustus was Claudius's paternal grandfather.In 9 BC, Claudius's father Drusus died on campaign in Germania from a fall from a horse.", "Claudius was then raised by his mother, who never remarried.", "When his disability became evident, the relationship with his family turned sour.", "Antonia referred to him as a monster, and used him as a standard for stupidity.", "She seems to have passed her son off to his grandmother Livia for a number of years.Livia was a little kinder, but nevertheless sent Claudius short, angry letters of reproof.", "He was put under the care of a former mule-driver to keep him disciplined, under the logic that his condition was due to laziness and a lack of willpower.", "However, by the time he reached his teenage years, his symptoms apparently waned and his family began to take some notice of his scholarly interests.", "In AD 7, Livy was hired to tutor Claudius in history, with the assistance of Sulpicius Flavus.", "He spent a lot of his time with the latter, as well as the philosopher Athenodorus.", "Augustus, according to a letter, was surprised at the clarity of Claudius's oratory.=== Public life ===Claudius' work as an historian damaged his prospects for advancement in public life.", "According to Vincent Scramuzza and others, he began work on a history of the Civil Wars that was either too truthful or too critical of Octavian, then reigning as Caesar Augustus.", "In either case, it was far too early for such an account, and may have only served to remind Augustus that Claudius was Antony's descendant.", "His mother and grandmother quickly put a stop to it, and this may have convinced them that Claudius was not fit for public office, since he could not be trusted to toe the existing party line.When Claudius returned to the narrative later in life, he skipped over the wars of the Second Triumvirate altogether; but the damage was done, and his family pushed him into the background.", "When the Arch of Pavia was erected to honor the Imperial clan in AD 8, Claudius's name (now Tiberius Claudius Nero Germanicus after his elevation to ''pater familias'' of the Claudii Nerones on the adoption of his brother) was inscribed on the edge, past the deceased princes, Gaius and Lucius, and Germanicus's children.", "There is some speculation that the inscription was added by Claudius himself decades later, and that he originally did not appear at all.When Augustus died in AD 14, Claudius – then aged 23 – appealed to his uncle Tiberius to allow him to begin the ''cursus honorum''.", "Tiberius, the new Emperor, responded by granting Claudius consular ornaments.", "Claudius requested office once more and was snubbed.", "Since the new emperor was no more generous than the old, Claudius gave up hope of public office and retired to a scholarly, private life.Despite the disdain of the Imperial family, it seems that from very early on the general public respected Claudius.", "At Augustus's death, the ''equites'', or knights, chose Claudius to head their delegation.", "When his house burned down, the Senate demanded it be rebuilt at public expense.", "They also requested that Claudius be allowed to debate in the Senate.", "Tiberius turned down both motions, but the sentiment remained.During the period immediately after the death of Tiberius's son, Drusus, Claudius was pushed by some quarters as a potential heir to the throne.", "This again suggests the political nature of his exclusion from public life.", "However, as this was also the period during which the power and terror of the commander of the Praetorian Guard, Sejanus, was at its peak, Claudius chose to downplay this possibility.", "After the death of Tiberius, the new emperor Caligula (the son of Claudius's brother Germanicus) recognized Claudius to be of some use.", "He appointed Claudius his co-consul in 37 to emphasize the memory of Caligula's deceased father Germanicus.Despite this, Caligula tormented his uncle: playing practical jokes, charging him enormous sums of money, humiliating him before the Senate, and the like.", "According to Cassius Dio, Claudius became sickly and thin by the end of Caligula's reign, most likely due to stress.", "A possible surviving portrait of Claudius from this period may support this.===Assassination of Caligula (AD 41)===A coin of Herod of Chalcis, showing him with his brother Agrippa of Judaea crowning Claudius, AD 43.On 24 January 41, Caligula was assassinated in a conspiracy involving Cassius Chaerea – a military tribune in the Praetorian Guard – and several senators.", "There is no evidence that Claudius had a direct hand in the assassination, although it has been argued that he knew about the plot – particularly since he left the scene of the crime shortly before his nephew was murdered.", "However, after the deaths of Caligula's wife and daughter, it became apparent that Cassius intended to go beyond the terms of the conspiracy and wipe out the Imperial family.In the chaos following the murder, Claudius witnessed the German guard cut down several uninvolved noblemen, including many of his friends.", "He fled to the palace to hide.", "According to tradition, a Praetorian named Gratus found him hiding behind a curtain and suddenly declared him ''princeps''.", "Claudius was spirited away to the Praetorian camp and put under their protection.The Senate met and debated a change of government, but this devolved into an argument over which of them would be the new ''princeps''.", "When they heard of the Praetorians' claim, they demanded that Claudius be delivered to them for approval, but he refused, sensing the danger that would come with complying.", "Some historians, particularly Josephus, claim that Claudius was directed in his actions by the Judaean King Herod Agrippa.", "However, an earlier version of events by the same ancient author downplays Agrippa's role so it remains uncertain.", "Eventually the Senate was forced to give in.", "In return, Claudius granted a general amnesty, although he executed a few junior officers involved in the conspiracy.", "The actual assassins, including Cassius Chaerea and Julius Lupus, the murderer of Caligula's wife and daughter, were put to death to ensure Claudius's own safety and as a future deterrent." ], [ "As Emperor", "Claudius took several steps to legitimize his rule against potential usurpers, most of them emphasizing his place within the Julio-Claudian family.", "He adopted the name \"Caesar\" as a cognomen, as the name still carried great weight with the populace.", "To do so, he dropped the cognomen \"Nero\", which he had adopted as ''pater familias'' of the Claudii Nerones when his brother Germanicus was adopted.", "As Pharaoh of Egypt, Claudius adopted the royal titulary ''Tiberios Klaudios, Autokrator Heqaheqau Meryasetptah, Kanakht Djediakhshuemakhet'' (\"Tiberius Claudius, Emperor and ruler of rulers, beloved of Isis and Ptah, the strong bull of the stable moon on the horizon\").While Claudius had never been formally adopted either by Augustus or his successors, he was nevertheless the grandson of Augustus's sister Octavia, and so he felt that he had the right of family.", "He also adopted the name \"Augustus\" as the two previous emperors had done at their accessions.", "He kept the honorific \"Germanicus\" to display the connection with his heroic brother.", "He deified his paternal grandmother Livia to highlight her position as wife of the divine Augustus.", "Claudius frequently used the term \"filius Drusi\" (son of Drusus) in his titles, to remind the people of his legendary father and lay claim to his reputation.Since Claudius was the first emperor proclaimed on the initiative of the Praetorian Guard instead of the Senate, his repute suffered at the hands of commentators (such as Seneca).", "Moreover, he was the first emperor who resorted to bribery as a means to secure army loyalty and rewarded the soldiers of the Praetorian Guard that had elevated him with 15,000 sesterces.", "Tiberius and Augustus had both left gifts to the army and guard in their wills, and upon Caligula's death the same would have been expected, even if no will existed.", "Claudius remained grateful to the guard, issuing coins with tributes to the Praetorians in the early part of his reign.Pliny the Elder noted, according to the 1938 Loeb Classical Library translation by Harris Rackham, \"... many people do not allow any gems in a signet-ring, and seal with the gold itself; this was a fashion invented when Claudius Cæsar was emperor.", "\"Claudius restored the status of the peaceful Imperial Roman provinces of Macedonia and Achaea as senatorial provinces.===Expansion of the Empire===Bronze head of Claudius found in the River Alde at Rendham, near Saxmundham, Suffolk (British Museum).", "Potentially taken from the Temple of Claudius in Colonia Victricensis (now Colchester) during the Boudican revolt.Under Claudius, the Empire underwent its first major expansion since the reign of Augustus.", "The provinces of Thrace, Noricum, Lycia, and Judea were annexed (or put under direct rule) under various circumstances during his term.", "The annexation of Mauretania, begun under Caligula, was completed after the defeat of rebel forces, as well as the official division of the former client kingdom into two Imperial provinces.", "The most far-reaching conquest was that of Britannia.In 43, Claudius sent Aulus Plautius with four legions to Britain (''Britannia'') after an appeal from an ousted tribal ally.", "Britain was an attractive target for Rome because of its material wealth: mines and the potential of slave labor, as well as being a haven for Gallic rebels.", "Claudius himself traveled to the island after the completion of initial offensives, bringing with him reinforcements and elephants.", "The Roman ''colonia'' of ''Colonia Claudia Victricensis'' was established as the provincial capital of the newly established province of Britannia at Camulodunum, where a large temple was dedicated in his honour.He left Britain after 16 days, but remained in the provinces for some time.", "The Senate granted him a triumph for his efforts.", "Only members of the Imperial family were allowed such honours, but Claudius subsequently lifted this restriction for some of his conquering generals.", "He was granted the honorific \"Britannicus\" but only accepted it on behalf of his son, never using the title himself.", "When the British general Caractacus was captured in 50, Claudius granted him clemency.", "Caractacus lived out his days on land provided by the Roman state, an unusual end for an enemy commander.Claudius conducted a census in 48 that found 5,984,072 (adult male) Roman citizens (women, children, slaves, and free adult males without Roman citizenship were not counted), an increase of around a million since the census conducted at Augustus's death.", "He had helped increase this number through the foundation of Roman colonies that were granted blanket citizenship.", "These colonies were often made out of existing communities, especially those with elites who could rally the populace to the Roman cause.", "Several colonies were placed in new provinces or on the border of the Empire to secure Roman holdings as quickly as possible.===Judicial and legislative affairs===Claudius personally judged many of the legal cases tried during his reign.", "Ancient historians have many complaints about this, stating that his judgments were variable and sometimes did not follow the law.", "He was also easily swayed.", "Nevertheless, Claudius paid detailed attention to the operation of the judicial system.", "He extended the summer court session, as well as the winter term, by shortening the traditional breaks.", "Claudius also made a law requiring plaintiffs to remain in the city while their cases were pending, as defendants had previously been required to do.", "These measures had the effect of clearing out the docket.", "The minimum age for jurors was also raised to 25 to ensure a more experienced jury pool.Claudius also settled disputes in the provinces.", "He freed the island of Rhodes from Roman rule for their good faith and exempted Ilium (Troy) from taxes.", "Early in his reign, the Greeks and Jews of Alexandria each sent him embassies after riots broke out between the two communities.", "This resulted in the famous \"Letter to the Alexandrians\", which reaffirmed Jewish rights in the city but forbade them to move in more families en masse.", "According to Josephus, he then reaffirmed the rights and freedoms of all the Jews in the Empire.One of Claudius's investigators discovered that many old Roman citizens based in the city of Tridentum (modern Trento) were not in fact citizens.", "The Emperor issued a declaration, contained in the ''Tabula clesiana'', that they would be allowed to hold citizenship from then on, since to strip them of their status would cause major problems.", "However, in individual cases, Claudius punished the false assumption of citizenship harshly, making it a capital offense.", "Similarly, any freedmen found to be laying false claim to membership of the Roman equestrian order were sold back into slavery.Numerous edicts were issued throughout Claudius's reign.", "These were on a number of topics, everything from medical advice to moral judgments.", "A famous medical example is one promoting yew juice as a cure for snakebite.", "Suetonius wrote that he is even said to have thought of an edict allowing public flatulence for good health.", "One of the more famous edicts concerned the status of sick slaves.", "Masters had been abandoning ailing slaves at the temple of Aesculapius on Tiber Island to die instead of providing them with medical assistance and care, and then reclaiming them if they lived.", "Claudius ruled that slaves who were thus abandoned and recovered after such treatment would be free.", "Furthermore, masters who chose to kill slaves rather than take care of them were liable to be charged with murder.===Public works===The Porta Maggiore in Rome: remains of aqueducts Aqua Claudia and Aqua Anio NovusClaudius embarked on many public works throughout his reign, both in the capital and in the provinces.", "He built or finished two aqueducts, the Aqua Claudia, begun by Caligula, and the Aqua Anio Novus.", "These entered the city in 52 and met at the Porta Maggiore.", "He also restored a third, the Aqua Virgo.He paid special attention to transportation.", "Throughout Italy and the provinces he built roads and canals.", "Among these was a large canal leading from the Rhine to the sea, as well as a road from Italy to Germany – both begun by his father, Drusus.", "Closer to Rome, he built a navigable canal on the Tiber, leading to Portus, his new port just north of Ostia.", "This port was constructed in a semicircle with two moles and a lighthouse at its mouth, reducing flooding in Rome.The port at Ostia was part of Claudius's solution to the constant grain shortages that occurred in winter, after the Roman shipping season.", "The other part of his solution was to insure the ships of grain merchants who were willing to risk travelling to Egypt in the off-season.", "He also granted their sailors special privileges, including citizenship and exemption from the Lex Papia Poppaea, a law that regulated marriage.", "In addition, he repealed the taxes that Caligula had instituted on food, and further reduced taxes on communities suffering drought or famine.The last part of Claudius's plan to avoid famine was to increase the amount of arable land in Italy.", "This was to be achieved by draining the Fucine lake, also making the nearby river navigable year-round.", "A serious famine is mentioned in the book of Acts as taking place during Claudius' reign, and had been prophecied by a Christian called Agabus while visiting Antioch.A tunnel was dug through the lake bed, but the plan was a failure.", "The tunnel was crooked and not large enough to carry the water, which caused it to back up when opened.", "The resultant flood washed out a large gladiatorial exhibition held to commemorate the opening, causing Claudius to run for his life along with the other spectators.", "The draining of the lake continued to present a problem well into the Middle Ages.", "It was finally achieved by the Prince Torlonia in the 19th century, producing over of new arable land.", "He expanded the Claudian tunnel to three times its original size.===Senate===Because of the circumstances of his accession, Claudius took great pains to please the Senate.", "During regular sessions, the Emperor sat among the Senate body, speaking in turn.", "When introducing a law, he sat on a bench between the consuls in his position as holder of the power of Tribune, (the Emperor could not officially serve as a Tribune of the Plebes since he was a patrician, but this was a power taken by previous rulers, which he continued).", "He refused to accept all his predecessors' titles (including Imperator) at the beginning of his reign, preferring to earn them in due course.", "He allowed the Senate to issue its own bronze coinage for the first time since Augustus.", "He also put the Imperial provinces of Macedonia and Achaea back under Senate control.Claudius set about remodeling the Senate into a more efficient, representative body.", "He chided the senators about their reluctance to debate bills introduced by himself, as noted in the fragments of a surviving speech:In 47, he assumed the office of ''censor'' with Lucius Vitellius, which had been allowed to lapse for some time.", "He struck out the names of many senators and ''equites'' who no longer met qualifications, but showed respect by allowing them to resign in advance.", "At the same time, he sought to admit to the senate eligible men from the provinces.", "The Lyon Tablet preserves his speech on the admittance of Gallic senators, in which he addresses the Senate with reverence but also with criticism for their disdain of these men.", "He even joked about how the Senate had admitted members from beyond Gallia Narbonensis (Lyons), i.e.", "himself.", "He also increased the number of patricians by adding new families to the dwindling number of noble lines.", "Here he followed the precedent of Lucius Junius Brutus and Julius Caesar.Nevertheless, many in the Senate remained hostile to Claudius, and many plots were made on his life.", "This hostility carried over into the historical accounts.", "As a result, Claudius reduced the Senate's power for the sake of efficiency.", "The administration of Ostia was turned over to an Imperial procurator after construction of the port.", "Administration of many of the empire's financial concerns was turned over to Imperial appointees and freedmen.", "This led to further resentment and suggestions that these same freedmen were ruling the Emperor.==== Plots and coup attempts ====Several coup attempts were made during Claudius's reign, resulting in the deaths of many senators.", "Appius Silanus was executed early in Claudius's reign under questionable circumstances.", "Shortly after this, a large rebellion was undertaken by the Senator Vinicianus and Scribonianus - governor of Dalmatia - and gained quite a few senatorial supporters.", "It ultimately failed because of the reluctance of Scribonianus' troops, which led to the suicide of the main conspirators.Many other senators tried different conspiracies and were condemned.", "Claudius's son-in-law Pompeius Magnus was executed for his part in a conspiracy with his father Crassus Frugi.", "Another plot involved the consulars Lusius Saturninus, Cornelius Lupus, and Pompeius Pedo.In 46, Asinius Gallus, grandson of Asinius Pollio, and Titus Statilius Taurus Corvinus were exiled for a plot hatched with several of Claudius's own freedmen.", "Valerius Asiaticus was executed without public trial for unknown reasons.", "Ancient sources say the charge was adultery, and that Claudius was tricked into issuing the punishment.", "However, Claudius singles out Asiaticus for special damnation in his speech on the Gauls, which dates over a year later, suggesting that the charge must have been much more serious.Asiaticus had been a claimant to the throne in the chaos following Caligula's death and a co-consul with Titus Statilius Taurus Corvinus.", "Most of these conspiracies took place before Claudius's term as Censor, and may have induced him to review the Senatorial rolls.", "The conspiracy of Gaius Silius in the year after his Censorship, 48, is detailed in book 11 of Tacitus' Annal.", "This section of Tacitus' history narrates the alleged conspiracy of Claudius's third wife, Messalina.", "Suetonius states that a total of 35 senators and 300 knights were executed for offenses during Claudius's reign.", "Needless to say, the responses to these conspiracies could not have helped Senate–emperor relations.===Secretariat and centralization of powers===Claudius was hardly the first emperor to use freedmen to help with the day-to-day running of the Empire.", "He was, however, forced to increase their role as the powers of the ''princeps'' became more centralized and the burden of running the government became larger.", "Claudius did not want free-born magistrates to serve under him as if they were not peers.The secretariat was divided into bureaus, with each being placed under the leadership of one freedman.", "Narcissus was the secretary of correspondence.", "Pallas became the secretary of the treasury.", "Callistus became secretary of justice.", "There was a fourth bureau for miscellaneous issues, which was put under Polybius until his execution for treason.", "The freedmen could also officially speak for the Emperor, as when Narcissus addressed the troops in Claudius's stead before the conquest of Britain.Since these were important positions, the senators were aghast at their being placed in the hands of former slaves and \"well-known eunuchs\".", "If freedmen had total control of money, letters and law, it seemed it would not be hard for them to manipulate the Emperor.", "This is exactly the accusation put forth by ancient sources.", "However, these same sources admit that the freedmen were loyal to Claudius.He was similarly appreciative of them and gave them due credit for policies where he had used their advice.", "However, if they showed treasonous inclinations, the Emperor punished them with just force, as in the case of Polybius and Pallas's brother, Felix.", "There is no evidence that the character of Claudius's policies and edicts changed with the rise and fall of the various freedmen, suggesting that he was firmly in control throughout.Regardless of the extent of their political power, the freedmen did manage to amass wealth through their positions.", "Pliny the Elder notes that several of them were richer than Crassus, the richest man of the Republican era.===Religious reforms===Portrait of Claudius, Altes Museum, BerlinClaudius, as the author of a treatise on Augustus's religious reforms, felt himself in a good position to institute some of his own.", "He had strong opinions about the proper form for state religion.", "He refused the request of Alexandrian Greeks to dedicate a temple to his divinity, saying that only gods may choose new gods.", "He restored lost days to festivals and got rid of many extraneous celebrations added by Caligula.", "He re-instituted old observances and archaic language.Claudius was concerned with the spread of eastern mysteries within the city and searched for more Roman replacements.", "He emphasized the Eleusinian Mysteries, which had been practiced by so many during the Republic.", "He expelled foreign astrologers, and at the same time rehabilitated the old Roman soothsayers (known as haruspices) as a replacement.", "He was especially hard on Druidism, because of its incompatibility with the Roman state religion and its proselytizing activities.===Public games and entertainments===According to Suetonius, Claudius was extraordinarily fond of games.", "He is said to have risen with the crowd after gladiatorial matches and given unrestrained praise to the fighters.", "Claudius also presided over many new and original events.", "Soon after coming into power, Claudius instituted games to be held in honor of his father on the latter's birthday.", "Annual games were also held in honour of his accession, and took place at the Praetorian camp where Claudius had first been proclaimed Emperor.Claudius organised a performance of the Secular Games, marking the 800th anniversary of the founding of Rome.", "Augustus had performed the same games less than a century prior.", "Augustus's excuse was that the interval for the games was 110 years, not 100, but his date actually did not qualify under either reasoning.", "Claudius also presented staged naval battles to mark the attempted draining of the Fucine Lake, as well as many other public games and shows.At Ostia, in front of a crowd of spectators, Claudius fought an orca which was trapped in the harbour.", "The event was witnessed by Pliny the Elder:Claudius also restored and adorned many public venues in Rome.", "At the Circus Maximus, the turning posts and starting stalls were replaced in marble and embellished, and an embankment was probably added to prevent flooding of the track.", "Claudius also reinforced or extended the seating rules that reserved front seating at the Circus for senators.", "He rebuilt Pompey's Theatre after it had been destroyed by fire, organising special fights at the re-dedication, which he observed from a special platform in the orchestra box." ], [ "Marriages and personal life", "Suetonius and the other ancient authors accused Claudius of being dominated by women and wives, and of being a womanizer.Claudius married four times, after two failed betrothals.", "The first betrothal was to his distant cousin Aemilia Lepida, but was broken for political reasons.", "The second was to Livia Medullina Camilla, which ended with Medullina's sudden death on their wedding day.===Plautia Urgulanilla===Plautia Urgulanilla was the granddaughter of Livia's confidant Urgulania.", "During their marriage she gave birth to a son, Claudius Drusus.", "Drusus died of asphyxiation in his early teens, shortly after becoming engaged to Junilla, daughter of Sejanus.Claudius later divorced Urgulanilla for adultery and on suspicion of murdering her sister-in-law Apronia.", "When Urgulanilla gave birth after the divorce, Claudius repudiated the baby girl, Claudia, as the father was allegedly one of his own freedmen.", "Later, this action made him the target of criticism by his enemies.===Aelia Paetina===Soon after, (possibly in 28) Claudius married Aelia Paetina, a relative of Sejanus, if not Sejanus's adoptive sister.", "During their marriage, Claudius and Paetina had a daughter, Claudia Antonia.", "He later divorced her after the marriage became a political liability.", "One version suggests that it may have been due to emotional and mental abuse by Paetina.===Valeria Messalina===Messalina holding her son Britannicus, LouvreSome years after divorcing Aelia Paetina, in 38 or early 39, Claudius married Valeria Messalina, who was his first cousin once removed (Claudius's grandmother, Octavia the Younger, was Valeria's great-grandmother on both her mother and father's side) and closely allied with Caligula's circle.", "Shortly thereafter, she gave birth to a daughter, Claudia Octavia.", "A son, first named Tiberius Claudius Germanicus, and later known as Britannicus, was born just after Claudius's accession.This marriage ended in tragedy.", "The ancient historians allege that Messalina was a nymphomaniac who was regularly unfaithful to Claudius—Tacitus states she went so far as to compete with a prostitute to see who could have more sexual partners in a nightand manipulated his policies to amass wealth.", "In 48, Messalina married her lover Gaius Silius in a public ceremony while Claudius was at Ostia.", "''The Death of Messalina'' by Georges-Antoine Rochegrosse, 1916Sources disagree as to whether or not she divorced the Emperor first, and whether the intention was to usurp the throne.", "Under Roman law, the spouse needed to be informed that he or she had been divorced before a new marriage could take place; the sources state that Claudius was in total ignorance until after the marriage.", "Scramuzza, in his biography, suggests that Silius may have convinced Messalina that Claudius was doomed, and the union was her only hope of retaining her rank and protecting her children.", "The historian Tacitus suggests that Claudius's ongoing term as Censor may have prevented him from noticing the affair before it reached such a critical point, after which she was executed.===Agrippina the Younger===Claudius married once more.", "Ancient sources tell that his freedmen put forward three candidates, Caligula's third wife Lollia Paulina, Claudius's divorced second wife Aelia Paetina and Claudius's niece Agrippina the Younger.", "According to Suetonius, Agrippina won out through her feminine wiles.", "She gradually seized power from Claudius and successfully conspired to eliminate his son's rivals, opening the way for her son to become emperor.Sculpture of Agrippina crowning her young son Nero (c. AD 54–59)The truth is probably more political.", "The attempted coup d'état by Silius and Messalina probably made Claudius realize the weakness of his position as a member of the Claudian (but not the Julian) family.", "This weakness was compounded by the fact that he did not yet have an obvious adult heir, Britannicus being just a boy.", "Agrippina was one of the few remaining descendants of Augustus, and her son Lucius Domitius Ahenobarbus (the future Nero) was one of the last males of the Imperial family.", "Coup attempts might rally around the pair and Agrippina was already showing such ambition.", "It has been suggested that the Senate may have pushed for the marriage, an attempt to end the feud between the Julian and Claudian branches.This feud dated back to Agrippina's mother's actions against Tiberius after the death of her husband Germanicus (Claudius's brother), actions that Tiberius had punished.", "In any case, Claudius accepted Agrippina and later adopted the mature Ahenobarbus as his son, renaming him as 'Nero Claudius Caesar'.Nero was married to Claudius's daughter Octavia, made joint heir with the underage Britannicus, and promoted; Augustus had similarly named his grandson Postumus Agrippa and his stepson Tiberius as joint heirs, and Tiberius had named Caligula as his joint heir with his grandson Tiberius Gemellus.", "Adoption of adults or near adults was an old tradition in Rome when a suitable natural adult heir was unavailable, as was the case during Britannicus's minority.", "Claudius may have previously looked to adopt one of his sons-in-law to protect his own reign.Faustus Cornelius Sulla Felix, who was married to Claudius's daughter Claudia Antonia, was only descended from Octavia and Antony on one side – not close enough to the Imperial family insure his right to be Emperor (although that did not stop others from making him the object of a coup attempt against Nero a few years later), besides being the half-brother of Valeria Messalina, which told against him.", "Nero was more popular with the general public as both the grandson of Germanicus and the direct descendant of Augustus." ], [ "Affliction<!-- ! check for tone --> and personality", "The historian Suetonius describes the physical manifestations of Claudius's condition in relatively good detail.", "His knees were weak and gave way under him and his head shook.", "He stammered and his speech was confused.", "He slobbered and his nose ran when he was excited.", "The Stoic Seneca states in his ''Apocolocyntosis'' that Claudius's voice belonged to no land animal, and that his hands were weak as well.Roman god JupiterHowever, he showed no physical deformity, as Suetonius notes that when calm and seated he was a tall, well-built figure of ''dignitas''.", "When angered or stressed, his symptoms became worse.", "Historians agree that this condition improved upon his accession to the throne.", "Claudius himself claimed that he had exaggerated his ailments to save his life.Modern assessments of his health have changed several times in the past century.", "Prior to World War II, infantile paralysis (or polio) was widely accepted as the cause.", "This is the diagnosis used in Robert Graves's Claudius novels, first published in the 1930s.", "''The New York Times'' wrote in 1934 that Claudius suffered from infantile paralysis (which led to his limp state) and measles (which made him deaf) at seven months of age, among several other ailments.", "Polio does not explain many of the described symptoms, however, and a more recent theory implicates cerebral palsy as the cause.", "Tourette syndrome has also been considered a possibility.As a person, ancient historians described Claudius as generous and lowbrow, a man who sometimes lunched with the plebeians.", "They also paint him as bloodthirsty and cruel, over-fond of gladiatorial combat and executions, and very quick to anger; Claudius himself acknowledged the latter trait, and apologized publicly for his temper.", "According to the ancient historians he was also excessively trusting, and easily manipulated by his wives and freedmen, but at the same time they portray him as paranoid and apathetic, dull and easily confused.Claudius's extant works present a different view, painting a picture of an intelligent, scholarly, well-read, and conscientious administrator with an eye to detail and justice.", "Thus, Claudius becomes an enigma.", "Since the discovery of his \"Letter to the Alexandrians\", much work has been done to rehabilitate Claudius and determine the truth." ], [ "Scholarly works and their impact", "Claudius wrote copiously throughout his life.", "Arnaldo Momigliano states that during the reign of Tiberius, which covers the peak of Claudius's literary career, it became impolitic to speak of republican Rome.", "The trend among the young historians was either to write about the new empire or about obscure antiquarian topics.", "Claudius was the rare scholar who covered both.Besides his history of Augustus' reign that caused him so much grief, his major works included ''Tyrrhenika'', a twenty-book Etruscan history, and ''Carchedonica'', an eight-volume history of Carthage, as well as an Etruscan dictionary.", "He also wrote a book on dice-playing.", "Despite the general avoidance of the topic of the Republican era, he penned a defense of Cicero against the charges of Asinius Gallus.", "Modern historians have used this to determine the nature of his politics and of the aborted chapters of his civil war history.The Claudian lettersHe proposed a reform of the Latin alphabet by the addition of three new letters; he officially instituted the change during his censorship but they did not survive his reign.", "Claudius also tried to revive the old custom of putting dots between successive words (Classical Latin was written with no spacing).", "Finally, he wrote an eight-volume autobiography that Suetonius describes as lacking in taste.", "Claudius (like most of the members of his dynasty) harshly criticized his predecessors and relatives in surviving speeches.None of the works survived, but other sources' reference to him provide material for the surviving histories of the Julio-Claudian dynasty.", "Suetonius quotes Claudius's autobiography once and must have used it as a source numerous times.", "Tacitus uses Claudius's arguments for the orthographical innovations mentioned above and may have used him for some of the more antiquarian passages in his annals.", "Claudius is the source for numerous passages of Pliny's ''Natural History''.The influence of historical study on Claudius is obvious.", "In his speech on Gallic senators, he uses a version of the founding of Rome identical to that of Livy, his tutor in adolescence.", "The speech is meticulous in details, a common mark of all his extant works, and he goes into long digressions on related matters.", "This indicates a deep knowledge of a variety of historical subjects that he shared.", "Many of the public works instituted in his reign were based on plans first suggested by Julius Caesar.", "Levick believes this emulation of Caesar may have spread to all aspects of his policies.His censorship seems to have been based on those of his ancestors, particularly Appius Claudius Caecus, and he used the office to put into place many policies based on those of Republican times.", "This is when many of his religious reforms took effect; also, his building efforts greatly increased during his tenure.", "In fact, his assumption of the office of Censor may have been motivated by a desire to see his academic labors bear fruit.", "For example, he believed (as most Romans did) that Caecus had used the power of the censorship office to introduce the letter \"R\" and so used his own term to introduce his new letters." ], [ "Death", "A statue of Claudius at the Domvs Romana, MaltaAncient historians agree that Claudius was murdered by poison – possibly contained in mushrooms or on a feather (ostensibly put down his throat to induce vomiting) – and died in the early hours of 13 October 54.Nearly all implicate his final and powerful wife, Agrippina, as the instigator.", "Agrippina and Claudius had become more combative in the months leading up to his death.", "This carried on to the point where Claudius openly lamented his bad wives, and began to comment on Britannicus' approaching manhood with an eye towards restoring his status within the imperial family.", "Agrippina had motive in ensuring the succession of Nero before Britannicus could gain power.Some implicate either his taster Halotus, his doctor Xenophon, or the infamous poisoner Locusta as the administrator of the fatal substance.", "Some say he died after prolonged suffering following a single dose at dinner, and some have him recovering only to be poisoned again.", "Among his contemporary sources, Seneca the Younger ascribed the emperor's death to natural causes, while Josephus only spoke of rumors of his poisoning.Some historians have cast doubt on whether Claudius was murdered or merely died from illness or old age.", "Evidence against his murder include his serious illnesses in his last years, his unhealthy lifestyle and the fact that his taster Halotus continued to serve in the same position under Nero.", "Claudius had been so ill the year before that Nero vowed games for his recovery and the year of 54 seems to have been such an unhealthy year that one sitting member of each magistracy died within the span of a few months.", "He may even have died by eating a naturally poisonous mushroom, possibly Amanita muscaria.", "On the other hand, some modern scholars claim the near universality of the accusations in ancient texts lends credence to the crime.", "Claudius's ashes were interred in the Mausoleum of Augustus on 24 October 54, after a funeral similar to that of his great-uncle Augustus 40 years earlier." ], [ "Legacy", "===Divine honours===Already, while alive, he received the widespread private worship of a living ''princeps'' and was worshipped in Britannia in his own temple in Camulodunum.Claudius was deified by Nero and the Senate almost immediately.===Views of the new regime===Agrippina had sent Narcissus away shortly before Claudius's death, and now had the freedman murdered.The last act of this secretary of letters was to burn all of Claudius's correspondence – most likely so it could not be used against him and others in an already hostile new regime.", "Thus Claudius's private words about his own policies and motives were lost to history.", "Just as Claudius had criticized his predecessors in official edicts, Nero often criticized the deceased Emperor, and many Claudian laws and edicts were disregarded under the reasoning that he was too stupid and senile to have meant them.Seneca's Apocolocyntosis mocks the deification of Claudius and reinforces the view of Claudius as an unpleasant fool; this remained the official view for the duration of Nero's reign.", "Eventually Nero stopped referring to his deified adoptive father at all.", "Claudius's temple was left unfinished after only some of the foundation had been laid down.", "Eventually the site was overtaken by Nero's Golden House.===Flavian and later perspectives===The Flavians, who had risen to prominence under Claudius, took a different tack.", "They needed to shore up their legitimacy, but also justify the fall of the Julio-Claudians.", "They reached back to Claudius in contrast with Nero, to show that they were associated with a good regime.", "Commemorative coins were issued of Claudius and his son Britannicus, who had been a friend of Emperor Titus (Titus was born in 39, Britannicus was born in 41).", "When Nero's Golden House was burned, the Temple of Claudius was finally completed on the Caelian Hill.However, as the Flavians became established, they needed to emphasize their own credentials more, and their references to Claudius ceased.", "Instead, he was lumped with the other emperors of the fallen dynasty.", "His state-cult in Rome probably continued until the abolition of all cults of dead Emperors by Maximinus Thrax in 237–238.The ''Feriale Duranum'', probably identical to the festival calendars of every regular army unit, assigns him a sacrifice of a steer on his birthday, the Kalends of August.", "And such commemoration (and consequent feasting) probably continued until the Christianization and disintegration of the army in the late 4th century.===Views of ancient historians===The ancient historians Tacitus, Suetonius (in ''The Twelve Caesars''), and Cassius Dio all wrote after the last of the Flavians had gone.", "All three were senators or ''equites''.", "They took the side of the Senate in most conflicts with the Princeps, invariably viewing him as being in the wrong.", "This resulted in biases, both conscious and unconscious.", "Suetonius lost access to the official archives shortly after beginning his work.", "He was forced to rely on second-hand accounts when it came to Claudius (with the exception of Augustus's letters, which had been gathered earlier).", "Suetonius painted Claudius as a ridiculous figure, belittling many of his acts and crediting his good works to his retinue.Tacitus wrote a narrative for his fellow senators and fitted each of the emperors into a simple mold of his choosing.", "He wrote of Claudius as a passive pawn and an idiot in affairs relating to the palace and public life.", "During his Censorship of 47–48 Tacitus allows the reader a glimpse of a Claudius who is more statesmanlike (XI.23–25), but it is a mere glimpse.", "Tacitus is usually held to have 'hidden' his use of Claudius's writings and to have omitted Claudius's character from his works.", "Even his version of Claudius's Lyons tablet speech is edited to be devoid of the emperor's personality.", "Dio was less biased, but seems to have used Suetonius and Tacitus as sources.", "Thus, the conception of Claudius as a weak fool, controlled by those he supposedly ruled, was preserved for the ages.As time passed, Claudius was mostly forgotten outside of the historians' accounts.", "His books were lost first, as their antiquarian subjects became unfashionable.", "In the 2nd century, Pertinax, who shared his birthday, became emperor, overshadowing commemoration of Claudius." ], [ "In modern media", "* The best known fictional representation of the Emperor Claudius was contained in the books ''I, Claudius'' and ''Claudius the God'' (published in 1934 and 1935, respectively) by Robert Graves, both written in the first-person to give the reader the impression that they are Claudius's autobiography.", "Graves employed a fictive artifice to suggest that they were recently discovered, genuine translations of Claudius's writings.", "Claudius's extant letters, speeches, and sayings were incorporated into the text (mostly in the second book, ''Claudius the God''), to add authenticity.", "** In 1937, director Josef von Sternberg attempted a film version of ''I, Claudius'', with Charles Laughton as Claudius.", "However, the lead actress, Merle Oberon, had a near-fatal car accident and the movie was never finished.", "The surviving reels were featured in the BBC documentary ''The Epic That Never Was'' (1965).", "The motion picture rights for a new film eventually passed to producer Scott Rudin.", "** Graves's two books were the basis for a British television adaptation ''I, Claudius'', produced by the BBC.", "The series starred Derek Jacobi as Claudius and was broadcast in 1976 on BBC2.It was a substantial critical success, and won several BAFTA awards.", "The series was later broadcast in the United States on ''Masterpiece Theatre'' in 1977.The 1996 7-VHS release and the later DVD release of the television series, include ''The Epic That Never Was'' documentary.", "** A radio adaptation of the Graves novels by Robin Brooks and directed by Jonquil Panting, was broadcast in six one-hour episodes on BBC Radio 4 beginning 4 December 2010.The cast featured Tom Goodman-Hill as Claudius, Derek Jacobi as Augustus, Harriet Walter as Livia, Tim McInnerny as Tiberius and Samuel Barnett as Caligula.", "** In 2011, it was announced rights for a miniseries adaptation passed to HBO and BBC Two.", "Anne Thomopoulos and Jane Tranter, producers of the popular HBO–BBC2 ''Rome'' miniseries, were attached to the ''I, Claudius'' project.", "However, as of 2018, it has yet to be produced, and no release date is pending.", "* The 1954 film ''Demetrius and the Gladiators'' also portrayed him sympathetically, played by Barry Jones.", "* In the 1960 film ''Messalina'', Claudius is portrayed by Mino Doro.", "* On television, Freddie Jones portrayed Claudius in the 1968 British television series ''The Caesars''.", "* The 1975 TV Special ''Further Up Pompeii!''", "(based on the Frankie Howerd sit-com ''Up Pompeii!'')", "featured Cyril Appleton as Claudius.", "* In the 1979 motion picture ''Caligula'', where the role was performed by Giancarlo Badessi, Claudius is depicted as an idiot, in contrast to Robert Graves' portrait of Claudius as a cunning and deeply intelligent man, who is perceived by others to be an idiot.", "* In the 1981 Franco-Italian film ''Caligula and Messalina'', he was portrayed by Gino Turini (as John Turner).", "* The 1985 made-for-television miniseries ''A.D.''", "features actor Richard Kiley as Claudius.", "Kiley portrays him as thoughtful, but willing to cater to public opinion as well as being under the influence of Agrippina.", "* In the 2004 TV film ''Imperium: Nero'', Claudius is portrayed by Massimo Dapporto.", "* He is portrayed in Season 3 of the Netflix documentary series ''Roman Empire'', which focused on the reign of Caligula, by Kelson Henderson.", "The series concludes with Claudius's accession.", "* There is also a reference to Claudius's suppression of a coup in the movie ''Gladiator'', though that incident is entirely fictional.", "* In the series Britannia (2018), Claudius visits Britannia, played by Steve Pemberton as a fool who is drugged by Aulus Plautius.", "* He is portrayed by Derek Jacobi in the 2019 BBC film Horrible Histories: The Movie - Rotten RomansIn literature, Claudius and his contemporaries appear in the historical novel ''The Roman'' by Mika Waltari.", "Canadian-born science fiction writer A. E. van Vogt reimagined Robert Graves's Claudius story, in his two novels, ''Empire of the Atom'' and ''The Wizard of Linn''.The historical novel ''Chariot of the Soul'' by Linda Proud features Claudius as host and mentor of the young Togidubnus, son of King Verica of the Atrebates, during his ten-year stay in Rome.", "When Togidubnus returns to Britain in advance of the Roman army, it is with a mission given to him by Claudius." ], [ "See also", "* Julio-Claudian family tree* List of Roman emperors* Temple of Claudius" ], [ "Notes" ], [ "References" ], [ "Bibliography", "===Ancient sources===******===Modern sources===* * * * * * * * * * * * * * * * *" ], [ "External links", "* '''Works by Claudius'''** Claudius' Letter to the Alexandrians** Lyon Tablet*** Second half of the Lyons Tablet*** Tacitus' version of the Lyons Tablet speech** Edict confirming the rights of the people of Trent.", "Full Latin text here.", "* Biography from De Imperatoribus Romanis* Claudius Page* Claudius I at BBC History" ] ]
wikipedia
[ [ "Cardinal" ], [ "Introduction", "'''Cardinal''' or '''The Cardinal''' may refer to:" ], [ "Animals", "===Birds===* Cardinalidae, a family of North and South American birds**''Cardinalis'', genus of three species in the family Cardinalidae***Northern cardinal, ''Cardinalis cardinalis'', the common cardinal of eastern North America***Pyrrhuloxia or desert cardinal, ''Cardinalis sinuatus'', found in southwest North America ***Vermilion cardinal, ''Cardinalis phoeniceus'', found in Colombia and Venezuela* ''Paroaria'', a South American genus of birds in the family Thraupidae commonly called red-headed cardinals or cardinal-tanagers*Yellow cardinal, ''Gubernatrix cristata'' a South American bird in the family Thraupidae===Other animals===* ''Argynnis pandora'', a species of butterfly* Cardinal tetra, a freshwater fish" ], [ "Businesses", "* Cardinal Brewery, a brewery founded in 1788 by François Piller, located in Fribourg, Switzerland* Cardinal Health, a health care services company* Cardinal Technologies, a defunct modem manufacturer" ], [ "Christianity", "* Cardinal (Catholic Church), a senior official of the Catholic Church**Member of the College of Cardinals* Cardinal (Church of England), either of two members of the College of Minor Canons of St. Paul's Cathedral" ], [ "Entertainment", "===Films===* ''Cardinals'' (film), a 2017 Canadian film* ''The Cardinal'' (1936 film), a British historical drama* ''The Cardinal'', a 1963 American film===Games===* Cardinal (chess), a fairy chess piece, also known as the archbishop* Cardinal, a participant in the army drinking game Cardinal Puff===Music=======Groups====* Cardinal (band), indie pop duo formed in 1992* The Cardinals (rock band), a group formed in 2003* The Cardinals, a 1950s R&B group====Albums====* ''Cardinal'' (Cardinal album), 1994* ''Cardinal'' (Pinegrove album), 2016===Television===* ''Cardinal'' (TV series), a 2017 Canadian television series* \"Cardinal\" (''The Americans''), the second episode of the second season of the television series ''The Americans''===Other arts, entertainment, and media===* Cardinal (comics), a supervillain appearing in Marvel Comics* ''The Cardinal'' (1641 play), a Caroline era tragedy by James Shirley* ''The Cardinal'' (1901 play), a historical play by the British writer Louis N. Parker* The Cardinal System, a system appearing in the ''Sword Art Online'' series* Cardinal, a stormtrooper officer featured in ''Star Wars: Phasma'', a novel by Delilah S. Dawson" ], [ "Linguistics", "* Cardinal numeral, a part of speech for expressing numbers by name* Cardinal vowel, a concept in phonetics" ], [ "Mathematics", "* Cardinal number** Large cardinal" ], [ "Navigation", "* Cardinal direction, one of the four primary directions: north, south, east, and west* Cardinal mark, a sea mark used in navigation" ], [ "Places", "* Cardinal, Manitoba, Canada* Cardinal, Ontario, Canada* Cardinal High School (Middlefield, Ohio), a public high school in Middlefield, Ohio, Geauga County, United States* Cardinal Mountain, a summit in California* Cardinal Power Plant, a power plant in Jefferson County, Ohio* Cardinal, Virginia, United States* C/2008 T2 (Cardinal), a comet" ], [ "Plants", "* Cardinal (grape), a table grape first produced in California in 1939* ''Lobelia cardinalis'', also known as \"cardinal flower\"" ], [ "Sports", "* Arizona Cardinals, an American professional football team* Assindia Cardinals, an American football club from Essen, Germany* Ball State Cardinals, the athletic teams of Ball State University* Cardenales de Lara, a Venezuelan baseball team* Catholic University Cardinals, the athletic teams of the Catholic University of America* Front Royal Cardinals, an American baseball team*Incarnate Word Cardinals, the athletic teams of the University of the Incarnate Word* Lamar Cardinals, the athletic teams of Lamar University in Beaumont, Texas, USA* Louisville Cardinals, the athletic teams of University of Louisville* Mapúa Cardinals, the athletic teams of Mapúa University* North Central Cardinals, the athletic teams of North Central College* St. John Fisher Cardinals, the athletic teams of St. John Fisher College in Rochester, NY* St. Louis Cardinals, an American professional baseball team* Stanford Cardinal, the athletic teams of Stanford University; named for the color but not the bird* Wesleyan Cardinals, the athletic teams of Wesleyan University* West Perth Football Club, an Australian rules football club in Western Australia* Woking F.C., an English football team" ], [ "Transport", "===Aircraft===* Cessna 177 Cardinal, a single engine aircraft* St. Louis Cardinal C-2-110, a light aircraft built in 1928* NCSIST Cardinal, a family of small UAVs===Trains===* ''Cardinal'' (train)* ''The Cardinal'' (railcar)" ], [ "Other uses", "* Cardinal (color), a vivid red* Cardinal (name), a surname* Cardinal, a Ruby programming language implementation using for the Parrot virtual machine" ], [ "See also", "* Cardenal, a surname* Cardinal sin or cardinal syn* Cardinale, a surname" ] ]
wikipedia
[ [ "Cantor set" ], [ "Introduction", "In mathematics, the '''Cantor set''' is a set of points lying on a single line segment that has a number of unintuitive properties.", "It was discovered in 1874 by Henry John Stephen Smith and mentioned by German mathematician Georg Cantor in 1883.Through consideration of this set, Cantor and others helped lay the foundations of modern point-set topology.", "The most common construction is the '''Cantor ternary set''', built by removing the middle third of a line segment and then repeating the process with the remaining shorter segments.", "Cantor mentioned this ternary construction only in passing, as an example of a perfect set that is nowhere dense (, Anmerkungen zu §10, /p.590).More generally, in topology, ''a'' Cantor space is a topological space homeomorphic to the Cantor ternary set (equipped with its subspace topology).", "By a theorem of L. E. J. Brouwer, this is equivalent to being perfect, nonempty, compact, metrizable and zero dimensional.Expansion of a Cantor set.", "Each point in the set is represented here by a vertical line." ], [ "Construction and formula of the ternary set", "The Cantor ternary set is created by iteratively deleting the ''open'' middle third from a set of line segments.", "One starts by deleting the open middle third from the interval , leaving two line segments: .", "Next, the open middle third of each of these remaining segments is deleted, leaving four line segments: .The Cantor ternary set contains all points in the interval that are not deleted at any step in this infinite process.", "The same facts can be described recursively by setting: and: for , so that:   for any   .The first six steps of this process are illustrated below.Cantor ternary set, in seven iterationsUsing the idea of self-similar transformations, and the explicit closed formulas for the Cantor set are: where every middle third is removed as the open interval from the closed interval surrounding it, or: where the middle third of the foregoing closed interval is removed by intersecting with This process of removing middle thirds is a simple example of a finite subdivision rule.", "The complement of the Cantor ternary set is an example of a fractal string.400pxIn arithmetical terms, the Cantor set consists of all real numbers of the unit interval that do not require the digit 1 in order to be expressed as a ternary (base 3) fraction.", "As the above diagram illustrates, each point in the Cantor set is uniquely located by a path through an infinitely deep binary tree, where the path turns left or right at each level according to which side of a deleted segment the point lies on.", "Representing each left turn with 0 and each right turn with 2 yields the ternary fraction for a point.=== Mandelbrot's construction by \"curdling\" ===In The Fractal Geometry of Nature, mathematician Benoit Mandelbrot provides a whimsical thought experiment to assist non-mathematical readers in imagining the construction of .", "His narrative begins with imagining a bar, perhaps of lightweight metal, in which the bar's matter \"curdles\" by iteratively shifting towards its extremities.", "As the bar's segments become smaller, they become thin, dense slugs that eventually grow too small and faint to see.CURDLING: The construction of the Cantor bar results from the process I call curdling.", "It begins with a round bar.", "It is best to think of it as having a very low density.", "Then matter \"curdles\" out of this bar's middle third into the end thirds, so that the positions of the latter remain unchanged.", "Next matter curdles out of the middle third of each end third into its end thirds, and so on ad infinitum until one is left with an infinitely large number of infinitely thin slugs of infinitely high density.", "These slugs are spaced along the line in the very specific fashion induced by the generating process.", "In this illustration, curdling (which eventually requires hammering!)", "stops when both the printer's press and our eye cease to follow; the last line is indistinguishable from the last but one: each of its ultimate parts is seen as a gray slug rather than two parallel black slugs." ], [ "Composition", "Since the Cantor set is defined as the set of points not excluded, the proportion (i.e., measure) of the unit interval remaining can be found by total length removed.", "This total is the geometric progression:So that the proportion left is 1 − 1 = 0.This calculation suggests that the Cantor set cannot contain any interval of non-zero length.", "It may seem surprising that there should be anything left—after all, the sum of the lengths of the removed intervals is equal to the length of the original interval.", "However, a closer look at the process reveals that there must be something left, since removing the \"middle third\" of each interval involved removing open sets (sets that do not include their endpoints).", "So removing the line segment (, ) from the original interval 0, 1 leaves behind the points and .", "Subsequent steps do not remove these (or other) endpoints, since the intervals removed are always internal to the intervals remaining.", "So the Cantor set is not empty, and in fact contains an uncountably infinite number of points (as follows from the above description in terms of paths in an infinite binary tree).It may appear that ''only'' the endpoints of the construction segments are left, but that is not the case either.", "The number , for example, has the unique ternary form 0.020202... = .", "It is in the bottom third, and the top third of that third, and the bottom third of that top third, and so on.", "Since it is never in one of the middle segments, it is never removed.", "Yet it is also not an endpoint of any middle segment, because it is not a multiple of any power of 1/3.All endpoints of segments are ''terminating'' ternary fractions and are contained in the set:which is a countably infinite set.As to cardinality, almost all elements of the Cantor set are not endpoints of intervals, nor rational points like 1/4.The whole Cantor set is in fact not countable." ], [ "Properties", "=== Cardinality ===It can be shown that there are as many points left behind in this process as there were to begin with, and that therefore, the Cantor set is uncountable.", "To see this, we show that there is a function ''f'' from the Cantor set to the closed interval 0,1 that is surjective (i.e.", "''f'' maps from onto 0,1) so that the cardinality of is no less than that of 0,1.Since is a subset of 0,1, its cardinality is also no greater, so the two cardinalities must in fact be equal, by the Cantor–Bernstein–Schröder theorem.To construct this function, consider the points in the 0, 1 interval in terms of base 3 (or ternary) notation.", "Recall that the proper ternary fractions, more precisely: the elements of , admit more than one representation in this notation, as for example , that can be written as 0.13 = 3, but also as 0.0222...3 = 3, and , that can be written as 0.23 = 3 but also as 0.1222...3 = 3.When we remove the middle third, this contains the numbers with ternary numerals of the form 0.1xxxxx...3 where xxxxx...3 is strictly between 00000...3 and 22222...3.So the numbers remaining after the first step consist of* Numbers of the form 0.0xxxxx...3 (including 0.022222...3 = 1/3)* Numbers of the form 0.2xxxxx...3 (including 0.222222...3 = 1)This can be summarized by saying that those numbers with a ternary representation such that the first digit after the radix point is not 1 are the ones remaining after the first step.The second step removes numbers of the form 0.01xxxx...3 and 0.21xxxx...3, and (with appropriate care for the endpoints) it can be concluded that the remaining numbers are those with a ternary numeral where neither of the first ''two'' digits is 1.Continuing in this way, for a number not to be excluded at step ''n'', it must have a ternary representation whose ''n''th digit is not 1.For a number to be in the Cantor set, it must not be excluded at any step, it must admit a numeral representation consisting entirely of 0s and 2s.It is worth emphasizing that numbers like 1, = 0.13 and = 0.213 are in the Cantor set, as they have ternary numerals consisting entirely of 0s and 2s: 1 = 0.222...3 = 3, = 0.0222...3 = 3 and = 0.20222...3 = 3.All the latter numbers are \"endpoints\", and these examples are right limit points of .", "The same is true for the left limit points of , e.g.", "= 0.1222...3 = 3 = 3 and = 0.21222...3 = 3 = 3.All these endpoints are ''proper ternary'' fractions (elements of ) of the form , where denominator ''q'' is a power of 3 when the fraction is in its irreducible form.", "The ternary representation of these fractions terminates (i.e., is finite) or — recall from above that proper ternary fractions each have 2 representations — is infinite and \"ends\" in either infinitely many recurring 0s or infinitely many recurring 2s.", "Such a fraction is a left limit point of if its ternary representation contains no 1's and \"ends\" in infinitely many recurring 0s.", "Similarly, a proper ternary fraction is a right limit point of if it again its ternary expansion contains no 1's and \"ends\" in infinitely many recurring 2s.This set of endpoints is dense in (but not dense in 0, 1) and makes up a countably infinite set.", "The numbers in which are ''not'' endpoints also have only 0s and 2s in their ternary representation, but they cannot end in an infinite repetition of the digit 0, nor of the digit 2, because then it would be an endpoint.The function from to 0,1 is defined by taking the ternary numerals that do consist entirely of 0s and 2s, replacing all the 2s by 1s, and interpreting the sequence as a binary representation of a real number.", "In a formula,:   where   For any number ''y'' in 0,1, its binary representation can be translated into a ternary representation of a number ''x'' in by replacing all the 1s by 2s.", "With this, ''f''(''x'') = ''y'' so that ''y'' is in the range of ''f''.", "For instance if ''y'' = = 0.100110011001...2 = , we write ''x'' = = 0.200220022002...3 = .", "Consequently, ''f'' is surjective.", "However, ''f'' is ''not'' injective — the values for which ''f''(''x'') coincides are those at opposing ends of one of the ''middle thirds'' removed.", "For instance, take: = 3 (which is a right limit point of and a left limit point of the middle third , )  and: = 3 (which is a left limit point of and a right limit point of the middle third , )so:Thus there are as many points in the Cantor set as there are in the interval 0, 1 (which has the uncountable cardinality However, the set of endpoints of the removed intervals is countable, so there must be uncountably many numbers in the Cantor set which are not interval endpoints.", "As noted above, one example of such a number is , which can be written as 0.020202...3 = in ternary notation.", "In fact, given any , there exist such that .", "This was first demonstrated by Steinhaus in 1917, who proved, via a geometric argument, the equivalent assertion that for every .", "Since this construction provides an injection from to , we have as an immediate corollary.", "Assuming that for any infinite set (a statement shown to be equivalent to the axiom of choice by Tarski), this provides another demonstration that .The Cantor set contains as many points as the interval from which it is taken, yet itself contains no interval of nonzero length.", "The irrational numbers have the same property, but the Cantor set has the additional property of being closed, so it is not even dense in any interval, unlike the irrational numbers which are dense in every interval.It has been conjectured that all algebraic irrational numbers are normal.", "Since members of the Cantor set are not normal, this would imply that all members of the Cantor set are either rational or transcendental.=== Self-similarity ===The Cantor set is the prototype of a fractal.", "It is self-similar, because it is equal to two copies of itself, if each copy is shrunk by a factor of 3 and translated.", "More precisely, the Cantor set is equal to the union of two functions, the left and right self-similarity transformations of itself, and , which leave the Cantor set invariant up to homeomorphism: Repeated iteration of and can be visualized as an infinite binary tree.", "That is, at each node of the tree, one may consider the subtree to the left or to the right.", "Taking the set together with function composition forms a monoid, the dyadic monoid.The automorphisms of the binary tree are its hyperbolic rotations, and are given by the modular group.", "Thus, the Cantor set is a homogeneous space in the sense that for any two points and in the Cantor set , there exists a homeomorphism with .", "An explicit construction of can be described more easily if we see the Cantor set as a product space of countably many copies of the discrete space .", "Then the map defined by is an involutive homeomorphism exchanging and .=== Conservation law===It has been found that some form of conservation law is always responsible behind scaling and self-similarity.", "In the case of Cantor set it can be seen that the th moment (where is the fractal dimension) of all the surviving intervals at any stage of the construction process is equal to a constant which is one in the case of the Cantor set.We know that there are intervals of size present in the system at the th step of its construction.", "Then if we label the surviving intervals as then the th moment is since .The Hausdorff dimension of the Cantor set is equal to ln(2)/ln(3) ≈ 0.631.=== Topological and analytical properties ===Although \"the\" Cantor set typically refers to the original, middle-thirds Cantor set described above, topologists often talk about \"a\" Cantor set, which means any topological space that is homeomorphic (topologically equivalent) to it.As the above summation argument shows, the Cantor set is uncountable but has Lebesgue measure 0.Since the Cantor set is the complement of a union of open sets, it itself is a closed subset of the reals, and therefore a complete metric space.", "Since it is also totally bounded, the Heine–Borel theorem says that it must be compact.For any point in the Cantor set and any arbitrarily small neighborhood of the point, there is some other number with a ternary numeral of only 0s and 2s, as well as numbers whose ternary numerals contain 1s.", "Hence, every point in the Cantor set is an accumulation point (also called a cluster point or limit point) of the Cantor set, but none is an interior point.", "A closed set in which every point is an accumulation point is also called a perfect set in topology, while a closed subset of the interval with no interior points is nowhere dense in the interval.Every point of the Cantor set is also an accumulation point of the complement of the Cantor set.For any two points in the Cantor set, there will be some ternary digit where they differ — one will have 0 and the other 2.By splitting the Cantor set into \"halves\" depending on the value of this digit, one obtains a partition of the Cantor set into two closed sets that separate the original two points.", "In the relative topology on the Cantor set, the points have been separated by a clopen set.", "Consequently, the Cantor set is totally disconnected.", "As a compact totally disconnected Hausdorff space, the Cantor set is an example of a Stone space.As a topological space, the Cantor set is naturally homeomorphic to the product of countably many copies of the space , where each copy carries the discrete topology.", "This is the space of all sequences in two digits :which can also be identified with the set of 2-adic integers.", "The basis for the open sets of the product topology are cylinder sets; the homeomorphism maps these to the subspace topology that the Cantor set inherits from the natural topology on the real line.", "This characterization of the Cantor space as a product of compact spaces gives a second proof that Cantor space is compact, via Tychonoff's theorem.From the above characterization, the Cantor set is homeomorphic to the ''p''-adic integers, and, if one point is removed from it, to the ''p''-adic numbers.The Cantor set is a subset of the reals, which are a metric space with respect to the ordinary distance metric; therefore the Cantor set itself is a metric space, by using that same metric.", "Alternatively, one can use the ''p''-adic metric on : given two sequences , the distance between them is , where is the smallest index such that ; if there is no such index, then the two sequences are the same, and one defines the distance to be zero.", "These two metrics generate the same topology on the Cantor set.We have seen above that the Cantor set is a totally disconnected perfect compact metric space.", "Indeed, in a sense it is the only one: every nonempty totally disconnected perfect compact metric space is homeomorphic to the Cantor set.", "See Cantor space for more on spaces homeomorphic to the Cantor set.The Cantor set is sometimes regarded as \"universal\" in the category of compact metric spaces, since any compact metric space is a continuous image of the Cantor set; however this construction is not unique and so the Cantor set is not universal in the precise categorical sense.", "The \"universal\" property has important applications in functional analysis, where it is sometimes known as the ''representation theorem for compact metric spaces''.For any integer ''q'' ≥ 2, the topology on the group G = '''Z'''''q''ω (the countable direct sum) is discrete.", "Although the Pontrjagin dual Γ is also '''Z'''''q''ω, the topology of Γ is compact.", "One can see that Γ is totally disconnected and perfect - thus it is homeomorphic to the Cantor set.", "It is easiest to write out the homeomorphism explicitly in the case ''q'' = 2.", "(See Rudin 1962 p 40.", ")===Measure and probability===The Cantor set can be seen as the compact group of binary sequences, and as such, it is endowed with a natural Haar measure.", "When normalized so that the measure of the set is 1, it is a model of an infinite sequence of coin tosses.", "Furthermore, one can show that the usual Lebesgue measure on the interval is an image of the Haar measure on the Cantor set, while the natural injection into the ternary set is a canonical example of a singular measure.", "It can also be shown that the Haar measure is an image of any probability, making the Cantor set a universal probability space in some ways.In Lebesgue measure theory, the Cantor set is an example of a set which is uncountable and has zero measure.", "In contrast, the set has a Hausdorff measure of 1 in its dimension of log 2 / log 3.===Cantor numbers===If we define a Cantor number as a member of the Cantor set, then# Every real number in 0, 2 is the sum of two Cantor numbers.# Between any two Cantor numbers there is a number that is not a Cantor number.=== Descriptive set theory ===The Cantor set is a meagre set (or a set of first category) as a subset of 0,1 (although not as a subset of itself, since it is a Baire space).", "The Cantor set thus demonstrates that notions of \"size\" in terms of cardinality, measure, and (Baire) category need not coincide.", "Like the set , the Cantor set is \"small\" in the sense that it is a null set (a set of measure zero) and it is a meagre subset of 0,1.However, unlike , which is countable and has a \"small\" cardinality, , the cardinality of is the same as that of 0,1, the continuum , and is \"large\" in the sense of cardinality.", "In fact, it is also possible to construct a subset of 0,1 that is meagre but of positive measure and a subset that is non-meagre but of measure zero: By taking the countable union of \"fat\" Cantor sets of measure (see Smith–Volterra–Cantor set below for the construction), we obtain a set which has a positive measure (equal to 1) but is meagre in 0,1, since each is nowhere dense.", "Then consider the set .", "Since , cannot be meagre, but since , must have measure zero." ], [ "Variants", "Radial plot of the first ten steps===Smith–Volterra–Cantor set===Instead of repeatedly removing the middle third of every piece as in the Cantor set, we could also keep removing any other fixed percentage (other than 0% and 100%) from the middle.", "In the case where the middle of the interval is removed, we get a remarkably accessible case — the set consists of all numbers in 0,1 that can be written as a decimal consisting entirely of 0s and 9s.", "If a fixed percentage is removed at each stage, then the limiting set will have measure zero, since the length of the remainder as for any such that .On the other hand, \"fat Cantor sets\" of positive measure can be generated by removal of smaller fractions of the middle of the segment in each iteration.", "Thus, one can construct sets homeomorphic to the Cantor set that have positive Lebesgue measure while still being nowhere dense.", "If an interval of length () is removed from the middle of each segment at the ''n''th iteration, then the total length removed is , and the limiting set will have a Lebesgue measure of .", "Thus, in a sense, the middle-thirds Cantor set is a limiting case with .", "If , then the remainder will have positive measure with .", "The case is known as the Smith–Volterra–Cantor set, which has a Lebesgue measure of .===Stochastic Cantor set===One can modify the construction of the Cantor set by dividing randomly instead of equally.", "Besides, to incorporate time we can divide only one of the available intervals at each step instead of dividing all the available intervals.", "In the case of stochastic triadic Cantor set the resulting process can be described by the following rate equation:and for the stochastic dyadic Cantor set:where is the number of intervals of size between and .", "In the case of triadic Cantor set the fractal dimension is which is less than its deterministic counterpart .", "In the case of stochastic dyadic Cantor setthe fractal dimension is which is again less than that of its deterministic counterpart .", "In the case of stochastic dyadic Cantor set the solution for exhibits dynamic scaling as its solution in the long-time limit is where the fractal dimension of the stochastic dyadic Cantor set .", "In either case, like triadic Cantor set, the th moment () of stochastic triadic and dyadic Cantor set too are conserved quantities.=== Cantor dust ==='''Cantor dust''' is a multi-dimensional version of the Cantor set.", "It can be formed by taking a finite Cartesian product of the Cantor set with itself, making it a Cantor space.", "Like the Cantor set, Cantor dust has zero measure.Cantor cubes recursion progression towards Cantor dust'''Cantor dust''' (2D)'''Cantor dust''' (3D)A different 2D analogue of the Cantor set is the Sierpinski carpet, where a square is divided up into nine smaller squares, and the middle one removed.", "The remaining squares are then further divided into nine each and the middle removed, and so on ad infinitum.", "One 3D analogue of this is the Menger sponge." ], [ "Historical remarks", "an image of the 2nd iteration of Cantor dust in two dimensionsan image of the 4th iteration of Cantor dust in two dimensionsCantor introduced what we call today the Cantor ternary set as an example \"of a perfect point-set, which is not everywhere-dense in any interval, however small.\"", "Cantor described in terms of ternary expansions, as \"the set of all real numbers given by the formula: where the coefficients arbitrarily take the two values 0 and 2, and the series can consist of a finite number or an infinite number of elements.", "\"A topological space is perfect if all its points are limit points or, equivalently, if it coincides with its derived set .", "Subsets of the real line, like , can be seen as topological spaces under the induced subspace topology.Cantor was led to the study of derived sets by his results on uniqueness of trigonometric series.", "The latter did much to set him on the course for developing an abstract, general theory of infinite sets.Benoit Mandelbrot wrote much on Cantor dusts and their relation to natural fractals and statistical physics.", "He further reflected on the puzzling or even upsetting nature of such structures to those in the mathematics and physics community.", "In The Fractal geometry of Nature, he described how \"When I started on this topic in 1962, everyone was agreeing that Cantor dusts are at least as monstrous as the Koch and Peano curves,\" and added that \"every self-respecting physicist was automatically turned off by a mention of Cantor, ready to run a mile from anyone claiming to be interesting in science.\"" ], [ "See also", "*an image of the 6th iteration of Cantor dust in two dimensionsThe indicator function of the Cantor set*Smith–Volterra–Cantor set*Cantor function*Cantor cube*Antoine's necklace*Koch snowflake*Knaster–Kuratowski fan*List of fractals by Hausdorff dimension*Moser–de Bruijn sequenceColumn capital with pattern evocative of the Cantor set, but expressed in binary rather than ternary.", "Engraving of Île de Philae from ''Description d'Égypte'' by Jean-Baptiste Prosper Jollois and Édouard Devilliers, Imprimerie Impériale, Paris, 1809-1828" ], [ "Notes" ], [ "References", "* * * * * .", "*" ], [ "External links", "* * Cantor Sets and Cantor Set and Function at cut-the-knot* Cantor Set at Platonic Realms" ] ]
wikipedia
[ [ "Cardinal number" ], [ "Introduction", "A bijective function, ''f'': ''X'' → ''Y'', from set ''X'' to set ''Y '' demonstrates that the sets have the same cardinality, in this case equal to the cardinal number 4.Aleph-null, the smallest infinite cardinalIn mathematics, a '''cardinal number''', or '''cardinal''' for short, is what is commonly called the number of elements of a set.", "In the case of a finite set, its cardinal number, or cardinality is therefore a natural number.", "For dealing with the case of infinite sets, the infinite cardinal numbers have been introduced, which are often denoted with the Hebrew letter (aleph) marked with subscript indicating their rank among the infinite cardinals.Cardinality is defined in terms of bijective functions.", "Two sets have the same cardinality if, and only if, there is a one-to-one correspondence (bijection) between the elements of the two sets.", "In the case of finite sets, this agrees with the intuitive notion of number of elements.", "In the case of infinite sets, the behavior is more complex.", "A fundamental theorem due to Georg Cantor shows that it is possible for infinite sets to have different cardinalities, and in particular the cardinality of the set of real numbers is greater than the cardinality of the set of natural numbers.", "It is also possible for a proper subset of an infinite set to have the same cardinality as the original set—something that cannot happen with proper subsets of finite sets.There is a transfinite sequence of cardinal numbers::This sequence starts with the natural numbers including zero (finite cardinals), which are followed by the aleph numbers.", "The aleph numbers are indexed by ordinal numbers.", "If the axiom of choice is true, this transfinite sequence includes every cardinal number.", "If the axiom of choice is not true (see ), there are infinite cardinals that are not aleph numbers.Cardinality is studied for its own sake as part of set theory.", "It is also a tool used in branches of mathematics including model theory, combinatorics, abstract algebra and mathematical analysis.", "In category theory, the cardinal numbers form a skeleton of the category of sets." ], [ "History", "The notion of cardinality, as now understood, was formulated by Georg Cantor, the originator of set theory, in 1874–1884.Cardinality can be used to compare an aspect of finite sets.", "For example, the sets {1,2,3} and {4,5,6} are not ''equal'', but have the ''same cardinality'', namely three.", "This is established by the existence of a bijection (i.e., a one-to-one correspondence) between the two sets, such as the correspondence {1→4, 2→5, 3→6}.Cantor applied his concept of bijection to infinite sets (for example the set of natural numbers '''N''' = {0, 1, 2, 3, ...}).", "Thus, he called all sets having a bijection with '''N''' ''denumerable (countably infinite) sets'', which all share the same cardinal number.", "This cardinal number is called , aleph-null.", "He called the cardinal numbers of infinite sets transfinite cardinal numbers.Cantor proved that any unbounded subset of '''N''' has the same cardinality as '''N''', even though this might appear to run contrary to intuition.", "He also proved that the set of all ordered pairs of natural numbers is denumerable; this implies that the set of all rational numbers is also denumerable, since every rational can be represented by a pair of integers.", "He later proved that the set of all real algebraic numbers is also denumerable.", "Each real algebraic number ''z'' may be encoded as a finite sequence of integers, which are the coefficients in the polynomial equation of which it is a solution, i.e.", "the ordered n-tuple (''a''0, ''a''1, ..., ''an''), ''ai'' ∈ '''Z''' together with a pair of rationals (''b''0, ''b''1) such that ''z'' is the unique root of the polynomial with coefficients (''a''0, ''a''1, ..., ''an'') that lies in the interval (''b''0, ''b''1).In his 1874 paper \"On a Property of the Collection of All Real Algebraic Numbers\", Cantor proved that there exist higher-order cardinal numbers, by showing that the set of real numbers has cardinality greater than that of '''N'''.", "His proof used an argument with nested intervals, but in an 1891 paper, he proved the same result using his ingenious and much simpler diagonal argument.", "The new cardinal number of the set of real numbers is called the cardinality of the continuum and Cantor used the symbol for it.Cantor also developed a large portion of the general theory of cardinal numbers; he proved that there is a smallest transfinite cardinal number (, aleph-null), and that for every cardinal number there is a next-larger cardinal:His continuum hypothesis is the proposition that the cardinality of the set of real numbers is the same as .", "This hypothesis is independent of the standard axioms of mathematical set theory, that is, it can neither be proved nor disproved from them.", "This was shown in 1963 by Paul Cohen, complementing earlier work by Kurt Gödel in 1940." ], [ "Motivation", "In informal use, a cardinal number is what is normally referred to as a ''counting number'', provided that 0 is included: 0, 1, 2, ....", "They may be identified with the natural numbers beginning with 0.The counting numbers are exactly what can be defined formally as the finite cardinal numbers.", "Infinite cardinals only occur in higher-level mathematics and logic.More formally, a non-zero number can be used for two purposes: to describe the size of a set, or to describe the position of an element in a sequence.", "For finite sets and sequences it is easy to see that these two notions coincide, since for every number describing a position in a sequence we can construct a set that has exactly the right size.", "For example, 3 describes the position of 'c' in the sequence , and we can construct the set {a,b,c}, which has 3 elements.However, when dealing with infinite sets, it is essential to distinguish between the two, since the two notions are in fact different for infinite sets.", "Considering the position aspect leads to ordinal numbers, while the size aspect is generalized by the cardinal numbers described here.The intuition behind the formal definition of cardinal is the construction of a notion of the relative size or \"bigness\" of a set, without reference to the kind of members which it has.", "For finite sets this is easy; one simply counts the number of elements a set has.", "In order to compare the sizes of larger sets, it is necessary to appeal to more refined notions.A set ''Y'' is at least as big as a set ''X'' if there is an injective mapping from the elements of ''X'' to the elements of ''Y''.", "An injective mapping identifies each element of the set ''X'' with a unique element of the set ''Y''.", "This is most easily understood by an example; suppose we have the sets ''X'' = {1,2,3} and ''Y'' = {a,b,c,d}, then using this notion of size, we would observe that there is a mapping:: 1 → a: 2 → b: 3 → cwhich is injective, and hence conclude that ''Y'' has cardinality greater than or equal to ''X''.", "The element d has no element mapping to it, but this is permitted as we only require an injective mapping, and not necessarily a bijective mapping.", "The advantage of this notion is that it can be extended to infinite sets.We can then extend this to an equality-style relation.", "Two sets ''X'' and ''Y'' are said to have the same ''cardinality'' if there exists a bijection between ''X'' and ''Y''.", "By the Schroeder–Bernstein theorem, this is equivalent to there being ''both'' an injective mapping from ''X'' to ''Y'', ''and'' an injective mapping from ''Y'' to ''X''.", "We then write |''X''| = |''Y''|.", "The cardinal number of ''X'' itself is often defined as the least ordinal ''a'' with |''a''| = |''X''|.", "This is called the von Neumann cardinal assignment; for this definition to make sense, it must be proved that every set has the same cardinality as ''some'' ordinal; this statement is the well-ordering principle.", "It is however possible to discuss the relative cardinality of sets without explicitly assigning names to objects.The classic example used is that of the infinite hotel paradox, also called Hilbert's paradox of the Grand Hotel.", "Supposing there is an innkeeper at a hotel with an infinite number of rooms.", "The hotel is full, and then a new guest arrives.", "It is possible to fit the extra guest in by asking the guest who was in room 1 to move to room 2, the guest in room 2 to move to room 3, and so on, leaving room 1 vacant.", "We can explicitly write a segment of this mapping:: 1 → 2: 2 → 3: 3 → 4: ...: ''n'' → ''n'' + 1: ...With this assignment, we can see that the set {1,2,3,...} has the same cardinality as the set {2,3,4,...}, since a bijection between the first and the second has been shown.", "This motivates the definition of an infinite set being any set that has a proper subset of the same cardinality (i.e., a Dedekind-infinite set); in this case {2,3,4,...} is a proper subset of {1,2,3,...}.When considering these large objects, one might also want to see if the notion of counting order coincides with that of cardinal defined above for these infinite sets.", "It happens that it does not; by considering the above example we can see that if some object \"one greater than infinity\" exists, then it must have the same cardinality as the infinite set we started out with.", "It is possible to use a different formal notion for number, called ordinals, based on the ideas of counting and considering each number in turn, and we discover that the notions of cardinality and ordinality are divergent once we move out of the finite numbers.It can be proved that the cardinality of the real numbers is greater than that of the natural numbers just described.", "This can be visualized using Cantor's diagonal argument; classic questions of cardinality (for instance the continuum hypothesis) are concerned with discovering whether there is some cardinal between some pair of other infinite cardinals.", "In more recent times, mathematicians have been describing the properties of larger and larger cardinals.Since cardinality is such a common concept in mathematics, a variety of names are in use.", "Sameness of cardinality is sometimes referred to as ''equipotence'', ''equipollence'', or ''equinumerosity''.", "It is thus said that two sets with the same cardinality are, respectively, ''equipotent'', ''equipollent'', or ''equinumerous''." ], [ "Formal definition", "Formally, assuming the axiom of choice, the cardinality of a set ''X'' is the least ordinal number α such that there is a bijection between ''X'' and α.", "This definition is known as the von Neumann cardinal assignment.", "If the axiom of choice is not assumed, then a different approach is needed.", "The oldest definition of the cardinality of a set ''X'' (implicit in Cantor and explicit in Frege and ''Principia Mathematica'') is as the class ''X'' of all sets that are equinumerous with ''X''.", "This does not work in ZFC or other related systems of axiomatic set theory because if ''X'' is non-empty, this collection is too large to be a set.", "In fact, for ''X'' ≠ ∅ there is an injection from the universe into ''X'' by mapping a set ''m'' to {''m''} × ''X'', and so by the axiom of limitation of size, ''X'' is a proper class.", "The definition does work however in type theory and in New Foundations and related systems.", "However, if we restrict from this class to those equinumerous with ''X'' that have the least rank, then it will work (this is a trick due to Dana Scott: it works because the collection of objects with any given rank is a set).Von Neumann cardinal assignment implies that the cardinal number of a finite set is the common ordinal number of all possible well-orderings of that set, and cardinal and ordinal arithmetic (addition, multiplication, power, proper subtraction) then give the same answers for finite numbers.", "However, they differ for infinite numbers.", "For example, in ordinal arithmetic while in cardinal arithmetic, although the von Neumann assignment puts .", "On the other hand, Scott's trick implies that the cardinal number 0 is , which is also the ordinal number 1, and this may be confusing.", "A possible compromise (to take advantage of the alignment in finite arithmetic while avoiding reliance on the axiom of choice and confusion in infinite arithmetic) is to apply von Neumann assignment to the cardinal numbers of finite sets (those which can be well ordered and are not equipotent to proper subsets) and to use Scott's trick for the cardinal numbers of other sets.Formally, the order among cardinal numbers is defined as follows: |''X''| ≤ |''Y''| means that there exists an injective function from ''X'' to ''Y''.", "The Cantor–Bernstein–Schroeder theorem states that if |''X''| ≤ |''Y''| and |''Y''| ≤ |''X''| then |''X''| = |''Y''|.", "The axiom of choice is equivalent to the statement that given two sets ''X'' and ''Y'', either |''X''| ≤ |''Y''| or |''Y''| ≤ |''X''|.A set ''X'' is Dedekind-infinite if there exists a proper subset ''Y'' of ''X'' with |''X''| = |''Y''|, and Dedekind-finite if such a subset does not exist.", "The finite cardinals are just the natural numbers, in the sense that a set ''X'' is finite if and only if |''X''| = |''n''| = ''n'' for some natural number ''n''.", "Any other set is infinite.Assuming the axiom of choice, it can be proved that the Dedekind notions correspond to the standard ones.", "It can also be proved that the cardinal (aleph null or aleph-0, where aleph is the first letter in the Hebrew alphabet, represented ) of the set of natural numbers is the smallest infinite cardinal (i.e., any infinite set has a subset of cardinality ).", "The next larger cardinal is denoted by , and so on.", "For every ordinal α, there is a cardinal number and this list exhausts all infinite cardinal numbers." ], [ "Cardinal arithmetic", "We can define arithmetic operations on cardinal numbers that generalize the ordinary operations for natural numbers.", "It can be shown that for finite cardinals, these operations coincide with the usual operations for natural numbers.", "Furthermore, these operations share many properties with ordinary arithmetic.=== Successor cardinal ===If the axiom of choice holds, then every cardinal κ has a successor, denoted κ+, where κ+ > κ and there are no cardinals between κ and its successor.", "(Without the axiom of choice, using Hartogs' theorem, it can be shown that for any cardinal number κ, there is a minimal cardinal κ+ such that ) For finite cardinals, the successor is simply κ + 1.For infinite cardinals, the successor cardinal differs from the successor ordinal.=== Cardinal addition ===If ''X'' and ''Y'' are disjoint, addition is given by the union of ''X'' and ''Y''.", "If the two sets are not already disjoint, then they can be replaced by disjoint sets of the same cardinality (e.g., replace ''X'' by ''X''×{0} and ''Y'' by ''Y''×{1}).", ":Zero is an additive identity ''κ'' + 0 = 0 + ''κ'' = ''κ''.Addition is associative (''κ'' + ''μ'') + ''ν'' = ''κ'' + (''μ'' + ''ν'').Addition is commutative ''κ'' + ''μ'' = ''μ'' + ''κ''.Addition is non-decreasing in both arguments::Assuming the axiom of choice, addition of infinite cardinal numbers is easy.", "If either ''κ'' or ''μ'' is infinite, then:==== Subtraction ====Assuming the axiom of choice and, given an infinite cardinal ''σ'' and a cardinal ''μ'', there exists a cardinal ''κ'' such that ''μ'' + ''κ'' = ''σ'' if and only if ''μ'' ≤ ''σ''.", "It will be unique (and equal to ''σ'') if and only if ''μ'' Y'' is the set of all functions from ''Y'' to ''X''.", ":κ0 = 1 (in particular 00 = 1), see empty function.", ":If 1 ≤ ''μ'', then 0''μ'' = 0.:1''μ'' = 1.:''κ''1 = ''κ''.", ":''κ''''μ'' + ''ν'' = ''κ''''μ''·''κ''''ν''.", ":κ''μ'' · ''ν'' = (''κ''''μ'')''ν''.", ":(''κ''·''μ'')''ν'' = ''κ''''ν''·''μ''''ν''.Exponentiation is non-decreasing in both arguments::(1 ≤ ''ν'' and ''κ'' ≤ ''μ'') → (''ν''''κ'' ≤ ''ν''''μ'') and:(''κ'' ≤ ''μ'') → (''κ''''ν'' ≤ ''μ''''ν'').2|''X''| is the cardinality of the power set of the set ''X'' and Cantor's diagonal argument shows that 2|''X''| > |''X''| for any set ''X''.", "This proves that no largest cardinal exists (because for any cardinal ''κ'', we can always find a larger cardinal 2''κ'').", "In fact, the class of cardinals is a proper class.", "(This proof fails in some set theories, notably New Foundations.", ")All the remaining propositions in this section assume the axiom of choice::If ''κ'' and ''μ'' are both finite and greater than 1, and ''ν'' is infinite, then ''κ''''ν'' = ''μ''''ν''.", ":If ''κ'' is infinite and ''μ'' is finite and non-zero, then ''κ''''μ'' = ''κ''.If 2 ≤ ''κ'' and 1 ≤ ''μ'' and at least one of them is infinite, then::Max (''κ'', 2''μ'') ≤ ''κ''''μ'' ≤ Max (2''κ'', 2''μ'').Using König's theorem, one can prove ''κ'' cf(''κ'') and ''κ'' ''κ'') for any infinite cardinal ''κ'', where cf(''κ'') is the cofinality of ''κ''.==== Roots ====Assuming the axiom of choice and, given an infinite cardinal ''κ'' and a finite cardinal ''μ'' greater than 0, the cardinal ''ν'' satisfying will be .==== Logarithms ====Assuming the axiom of choice and, given an infinite cardinal ''κ'' and a finite cardinal ''μ'' greater than 1, there may or may not be a cardinal ''λ'' satisfying .", "However, if such a cardinal exists, it is infinite and less than ''κ'', and any finite cardinality ''ν'' greater than 1 will also satisfy .The logarithm of an infinite cardinal number ''κ'' is defined as the least cardinal number ''μ'' such that ''κ'' ≤ 2''μ''.", "Logarithms of infinite cardinals are useful in some fields of mathematics, for example in the study of cardinal invariants of topological spaces, though they lack some of the properties that logarithms of positive real numbers possess." ], [ "The continuum hypothesis", "The continuum hypothesis (CH) states that there are no cardinals strictly between and The latter cardinal number is also often denoted by ; it is the cardinality of the continuum (the set of real numbers).", "In this case Similarly, the generalized continuum hypothesis (GCH) states that for every infinite cardinal , there are no cardinals strictly between and .", "Both the continuum hypothesis and the generalized continuum hypothesis have been proved to be independent of the usual axioms of set theory, the Zermelo–Fraenkel axioms together with the axiom of choice (ZFC).Indeed, Easton's theorem shows that, for regular cardinals , the only restrictions ZFC places on the cardinality of are that , and that the exponential function is non-decreasing." ], [ "See also", "* Aleph number* Beth number* The paradox of the greatest cardinal* Cardinal number (linguistics)* Counting* Inclusion–exclusion principle* Large cardinal* Names of numbers in English* Nominal number* Ordinal number* Regular cardinal" ], [ "References", "'''Notes''''''Bibliography'''**Hahn, Hans, ''Infinity'', Part IX, Chapter 2, Volume 3 of ''The World of Mathematics''.", "New York: Simon and Schuster, 1956.", "*Halmos, Paul, ''Naive set theory''.", "Princeton, NJ: D. Van Nostrand Company, 1960.Reprinted by Springer-Verlag, New York, 1974.", "(Springer-Verlag edition).", "*" ], [ "External links", "*" ] ]
wikipedia
[ [ "Cardinality" ], [ "Introduction", "The set of all Platonic solids has 5 elements.", "Thus the cardinality of is 5 or, in symbols, .In mathematics, the '''cardinality''' of a set is a measure of the number of elements of the set.", "For example, the set contains 3 elements, and therefore has a cardinality of 3.Beginning in the late 19th century, this concept was generalized to infinite sets, which allows one to distinguish between different types of infinity, and to perform arithmetic on them.", "There are two approaches to cardinality: one which compares sets directly using bijections and injections, and another which uses cardinal numbers.The cardinality of a set may also be called its '''size''', when no confusion with other notions of size is possible.The cardinality of a set is usually denoted , with a vertical bar on each side; this is the same notation as absolute value, and the meaning depends on context.", "The cardinality of a set may alternatively be denoted by , , , or ." ], [ "History", "A crude sense of cardinality, an awareness that groups of things or events compare with other groups by containing more, fewer, or the same number of instances, is observed in a variety of present-day animal species, suggesting an origin millions of years ago.", "Human expression of cardinality is seen as early as years ago, with equating the size of a group with a group of recorded notches, or a representative collection of other things, such as sticks and shells.", "The abstraction of cardinality as a number is evident by 3000 BCE, in Sumerian mathematics and the manipulation of numbers without reference to a specific group of things or events.From the 6th century BCE, the writings of Greek philosophers show hints of the cardinality of infinite sets.", "While they considered the notion of infinity as an endless series of actions, such as adding 1 to a number repeatedly, they did not consider the size of an infinite set of numbers to be a thing.", "The ancient Greek notion of infinity also considered the division of things into parts repeated without limit.", "In Euclid's ''Elements'', commensurability was described as the ability to compare the length of two line segments, ''a'' and ''b'', as a ratio, as long as there were a third segment, no matter how small, that could be laid end-to-end a whole number of times into both ''a'' and ''b''.", "But with the discovery of irrational numbers, it was seen that even the infinite set of all rational numbers was not enough to describe the length of every possible line segment.", "Still, there was no concept of infinite sets as something that had cardinality.To better understand infinite sets, a notion of cardinality was formulated circa 1880 by Georg Cantor, the originator of set theory.", "He examined the process of equating two sets with bijection, a one-to-one correspondence between the elements of two sets based on a unique relationship.", "In 1891, with the publication of Cantor's diagonal argument, he demonstrated that there are sets of numbers that cannot be placed in one-to-one correspondence with the set of natural numbers, i.e.", "uncountable sets that contain more elements than there are in the infinite set of natural numbers." ], [ "Comparing sets", "Bijective function from '''N''' to the set ''E'' of even numbers.", "Although ''E'' is a proper subset of '''N''', both sets have the same cardinality.", "'''N''' does not have the same cardinality as its power set ''P''('''N'''): For every function ''f'' from '''N''' to ''P''('''N'''), the set ''T'' = {''n''∈'''N''': ''n''∉''f''(''n'')} disagrees with every set in the range of ''f'', hence ''f'' cannot be surjective.", "The picture shows an example ''f'' and the corresponding ''T''; : ''n''∈''f''(''n'')\\''T'', :''n''∈''T''\\''f''(''n'').While the cardinality of a finite set is just the number of its elements, extending the notion to infinite sets usually starts with defining the notion of comparison of arbitrary sets (some of which are possibly infinite).===Definition 1: = ===:Two sets ''A'' and ''B'' have the same cardinality if there exists a bijection (a.k.a., one-to-one correspondence) from ''A'' to ''B'', that is, a function from ''A'' to ''B'' that is both injective and surjective.", "Such sets are said to be ''equipotent'', ''equipollent'', or ''equinumerous''.", "This relationship can also be denoted ''A'' ≈ ''B'' or ''A'' ~ ''B''.", ":For example, the set ''E'' = {0, 2, 4, 6, ...} of non-negative even numbers has the same cardinality as the set '''N''' = {0, 1, 2, 3, ...} of natural numbers, since the function ''f''(''n'') = 2''n'' is a bijection from '''N''' to ''E'' (see picture).", ":For finite sets ''A'' and ''B'', if ''some'' bijection exists from ''A'' to ''B'', then ''each'' injective or surjective function from ''A'' to ''B'' is a bijection.", "This is no longer true for infinite ''A'' and ''B''.", "For example, the function ''g'' from '''N''' to ''E'', defined by ''g''(''n'') = 4''n'' is injective, but not surjective, and ''h'' from '''N''' to ''E'', defined by ''h''(''n'') = ''n'' - (''n'' mod 2) is surjective, but not injective.", "Neither ''g'' nor ''h'' can challenge = , which was established by the existence of ''f''.===Definition 2: ≤ ===:''A'' has cardinality less than or equal to the cardinality of ''B'', if there exists an injective function from ''A'' into ''B''.===Definition 3: < ===:''A'' has cardinality strictly less than the cardinality of ''B'', if there is an injective function, but no bijective function, from ''A'' to ''B''.", ":For example, the set '''N''' of all natural numbers has cardinality strictly less than its power set ''P''('''N'''), because ''g''(''n'') = { ''n'' } is an injective function from '''N''' to ''P''('''N'''), and it can be shown that no function from '''N''' to ''P''('''N''') can be bijective (see picture).", "By a similar argument, '''N''' has cardinality strictly less than the cardinality of the set '''R''' of all real numbers.", "For proofs, see Cantor's diagonal argument or Cantor's first uncountability proof.If ≤ and ≤ , then = (a fact known as Schröder–Bernstein theorem).", "The axiom of choice is equivalent to the statement that ≤ or ≤ for every ''A'', ''B''." ], [ "Cardinal numbers", "In the above section, \"cardinality\" of a set was defined functionally.", "In other words, it was not defined as a specific object itself.", "However, such an object can be defined as follows.The relation of having the same cardinality is called equinumerosity, and this is an equivalence relation on the class of all sets.", "The equivalence class of a set ''A'' under this relation, then, consists of all those sets which have the same cardinality as ''A''.", "There are two ways to define the \"cardinality of a set\":#The cardinality of a set ''A'' is defined as its equivalence class under equinumerosity.#A representative set is designated for each equivalence class.", "The most common choice is the initial ordinal in that class.", "This is usually taken as the definition of cardinal number in axiomatic set theory.Assuming the axiom of choice, the cardinalities of the infinite sets are denoted:For each ordinal , is the least cardinal number greater than .The cardinality of the natural numbers is denoted aleph-null (), while the cardinality of the real numbers is denoted by \"\" (a lowercase fraktur script \"c\"), and is also referred to as the cardinality of the continuum.", "Cantor showed, using the diagonal argument, that .", "We can show that , this also being the cardinality of the set of all subsets of the natural numbers.The continuum hypothesis says that , i.e.", "is the smallest cardinal number bigger than , i.e.", "there is no set whose cardinality is strictly between that of the integers and that of the real numbers.", "The continuum hypothesis is independent of ZFC, a standard axiomatization of set theory; that is, it is impossible to prove the continuum hypothesis or its negation from ZFC—provided that ZFC is consistent.", "For more detail, see § Cardinality of the continuum below." ], [ "Finite, countable and uncountable sets", "If the axiom of choice holds, the law of trichotomy holds for cardinality.", "Thus we can make the following definitions:*Any set ''X'' with cardinality less than that of the natural numbers, or | ''X'' | , is said to be uncountable." ], [ "Infinite sets", "Our intuition gained from finite sets breaks down when dealing with infinite sets.", "In the late 19th century Georg Cantor, Gottlob Frege, Richard Dedekind and others rejected the view that the whole cannot be the same size as the part.", "One example of this is Hilbert's paradox of the Grand Hotel.Indeed, Dedekind defined an infinite set as one that can be placed into a one-to-one correspondence with a strict subset (that is, having the same size in Cantor's sense); this notion of infinity is called Dedekind infinite.", "Cantor introduced the cardinal numbers, and showed—according to his bijection-based definition of size—that some infinite sets are greater than others.", "The smallest infinite cardinality is that of the natural numbers ().===Cardinality of the continuum===One of Cantor's most important results was that the cardinality of the continuum () is greater than that of the natural numbers (); that is, there are more real numbers '''R''' than natural numbers '''N'''.", "Namely, Cantor showed that (see Beth one) satisfies:::(see Cantor's diagonal argument or Cantor's first uncountability proof).The continuum hypothesis states that there is no cardinal number between the cardinality of the reals and the cardinality of the natural numbers, that is,:However, this hypothesis can neither be proved nor disproved within the widely accepted ZFC axiomatic set theory, if ZFC is consistent.Cardinal arithmetic can be used to show not only that the number of points in a real number line is equal to the number of points in any segment of that line, but that this is equal to the number of points on a plane and, indeed, in any finite-dimensional space.", "These results are highly counterintuitive, because they imply that there exist proper subsets and proper supersets of an infinite set ''S'' that have the same size as ''S'', although ''S'' contains elements that do not belong to its subsets, and the supersets of ''S'' contain elements that are not included in it.The first of these results is apparent by considering, for instance, the tangent function, which provides a one-to-one correspondence between the interval (−½π, ½π) and '''R''' (see also Hilbert's paradox of the Grand Hotel).The second result was first demonstrated by Cantor in 1878, but it became more apparent in 1890, when Giuseppe Peano introduced the space-filling curves, curved lines that twist and turn enough to fill the whole of any square, or cube, or hypercube, or finite-dimensional space.", "These curves are not a direct proof that a line has the same number of points as a finite-dimensional space, but they can be used to obtain such a proof.Cantor also showed that sets with cardinality strictly greater than exist (see his generalized diagonal argument and theorem).", "They include, for instance::* the set of all subsets of '''R''', i.e., the power set of '''R''', written ''P''('''R''') or 2'''R''':* the set '''R''''''R''' of all functions from '''R''' to '''R'''Both have cardinality::(see Beth two).The cardinal equalities and can be demonstrated using cardinal arithmetic::::" ], [ "Examples and properties", "* If ''X'' = {''a'', ''b'', ''c''} and ''Y'' = {apples, oranges, peaches}, where ''a'', ''b'', and ''c'' are distinct, then | ''X'' | = | ''Y'' | because { (''a'', apples), (''b'', oranges), (''c'', peaches)} is a bijection between the sets ''X'' and ''Y''.", "The cardinality of each of ''X'' and ''Y'' is 3.", "* If | ''X'' | ≤ | ''Y'' |, then there exists ''Z'' such that | ''X'' | = | ''Z'' | and ''Z'' ⊆ ''Y''.", "*If | ''X'' | ≤ | ''Y'' | and | ''Y'' | ≤ | ''X'' |, then | ''X'' | = | ''Y'' |.", "This holds even for infinite cardinals, and is known as Cantor–Bernstein–Schroeder theorem.", "* Sets with cardinality of the continuum include the set of all real numbers, the set of all irrational numbers and the interval ." ], [ "Union and intersection", "If ''A'' and ''B'' are disjoint sets, then:From this, one can show that in general, the cardinalities of unions and intersections are related by the following equation::" ], [ "See also", "* Aleph number* Beth number* Cantor's paradox* Cantor's theorem* Countable set* Counting* Ordinality* Pigeonhole principle" ], [ "References" ] ]
wikipedia
[ [ "Cecil B. DeMille" ], [ "Introduction", "'''Cecil Blount DeMille''' (; August 12, 1881January 21, 1959) was an American filmmaker and actor.", "Between 1914 and 1958, he made 70 features, both silent and sound films.", "He is acknowledged as a founding father of American cinema and the most commercially successful producer-director in film history.", "His films were distinguished by their epic scale and by his cinematic showmanship.", "His silent films included social dramas, comedies, Westerns, farces, morality plays, and historical pageants.DeMille was born in Ashfield, Massachusetts, and grew up in New York City.", "He began his career as a stage actor in 1900.He later moved to writing and directing stage productions, some with Jesse Lasky, who was then a vaudeville producer.", "DeMille's first film, ''The Squaw Man'' (1914), was also the first full-length feature film shot in Hollywood.", "Its interracial love story made it commercially successful, and it first publicized Hollywood as the home of the U.S. film industry.", "The continued success of his productions led to the founding of Paramount Pictures with Lasky and Adolph Zukor.", "His first biblical epic, ''The Ten Commandments'' (1923), was both a critical and commercial success; it held the Paramount revenue record for twenty-five years.DeMille directed ''The King of Kings'' (1927), a biography of Jesus, which gained approval for its sensitivity and reached more than 800 million viewers.", "''The Sign of the Cross'' (1932) is said to be the first sound film to integrate all aspects of cinematic technique.", "''Cleopatra'' (1934) was his first film to be nominated for the Academy Award for Best Picture.", "After more than thirty years in film production, DeMille reached a pinnacle in his career with ''Samson and Delilah'' (1949), a biblical epic that became the highest-grossing film of 1950.Along with biblical and historical narratives, he also directed films oriented toward \"neo-naturalism\", which tried to portray the laws of man fighting the forces of nature.He received his first nomination for the Academy Award for Best Director for his circus drama ''The Greatest Show on Earth'' (1952), which won both the Academy Award for Best Picture and the Golden Globe Award for Best Motion Picture – Drama.", "His last and best known film, ''The Ten Commandments'' (1956), also a Best Picture Academy Award nominee, is currently the eighth-highest-grossing film of all time, adjusted for inflation.", "In addition to his Best Picture Awards, he received an Academy Honorary Award for his film contributions, the Palme d'Or (posthumously) for ''Union Pacific'' (1939), a DGA Award for Lifetime Achievement, and the Irving G. Thalberg Memorial Award.", "He was the first recipient of the Golden Globe Cecil B. DeMille Award, which was named in his honor.", "DeMille's reputation had a renaissance in the 2010s, and his work has influenced numerous other films and directors." ], [ "Biography", "===1881–1899: early years===alt=A multi-leveled brick building with many whitepaned windows with skycraper visible in the top right cornerCecil Blount DeMille was born on August 12, 1881, in a boarding house on Main Street in Ashfield, Massachusetts, where his parents had been vacationing for the summer.", "On September 1, 1881, the family returned with the newborn DeMille to their flat in New York.", "DeMille was named after his grandmothers Cecelia Wolff and Margarete Blount.", "He was the second of three children of Henry Churchill de Mille (September 4, 1853 – February 10, 1893) and his wife, Matilda Beatrice deMille (née Samuel; January 30, 1853 – October 8, 1923), known as Beatrice.", "His brother, William C. DeMille, was born on July 25, 1878.Henry de Mille, whose ancestors were of English and Dutch-Belgian descent, was a North Carolina-born dramatist, actor, and lay reader in the Episcopal Church.", "DeMille's father was also an English teacher at Columbia College (now Columbia University).", "He worked as a playwright, administrator, and faculty member during the early years of the American Academy of Dramatic Arts, established in New York City in 1884.Henry deMille frequently collaborated with David Belasco in playwriting; their best-known collaborations included \"The Wife\", \"Lord Chumley\", \"The Charity Ball\", and \"Men and Women\".Cecil B. DeMille's mother, Beatrice, a literary agent and scriptwriter, was the daughter of German Jews.", "She had emigrated from England with her parents in 1871 when she was 18; the newly arrived family settled in Brooklyn, New York, where they maintained a middle-class, English-speaking household.DeMille's parents met as members of a music and literary society in New York.", "Henry was a tall, red-headed student.", "Beatrice was intelligent, educated, forthright, and strong-willed.", "The two were married on July 1, 1876, despite Beatrice's parents' objections because of the young couple's differing religions; Beatrice converted to Episcopalianism.DeMille was a brave and confident child.", "He gained his love of theater while watching his father and Belasco rehearse their plays.", "A lasting memory for DeMille was a lunch with his father and actor Edwin Booth.", "As a child, DeMille created an alter ego, Champion Driver, a Robin Hood-like character, evidence of his creativity and imagination.", "The family lived in Washington, North Carolina, until Henry built a three-story Victorian-style house for his family in Pompton Lakes, New Jersey; they named this estate \"Pamlico\".", "John Philip Sousa was a friend of the family, and DeMille recalled throwing mud balls in the air so neighbor Annie Oakley could practice her shooting.", "DeMille's sister, Agnes, was born on April 23, 1891; his mother nearly did not survive the birth.", "Agnes would die on February 11, 1894, at the age of three from spinal meningitis.", "DeMille's parents operated a private school in town and attended Christ Episcopal Church.", "DeMille recalled that this church was the place where he visualized the story of his 1923 version of ''The Ten Commandments''.DeMille as a young man, c. 1904On January 8, 1893, at age 40, Henry de Mille died suddenly from typhoid fever, leaving Beatrice with three children.", "To provide for her family, she opened the Henry C. de Mille School for Girls in her home in February 1893.The aim of the school was to teach young women to properly understand and fulfill the women's duty to herself, her home, and her country.", "Before Henry de Mille's death, Beatrice had \"enthusiastically supported\" her husband's theatrical aspirations.", "She later became the second female play broker on Broadway.", "On Henry de Mille's deathbed, he told his wife that he did not want his sons to become playwrights.", "DeMille's mother sent him to Pennsylvania Military College (now Widener University) in Chester, Pennsylvania, at age 15.He fled the school to join the Spanish–American War, but failed to meet the age requirement.", "At the military college, even though his grades were average, he reportedly excelled in personal conduct.", "DeMille attended the American Academy of Dramatic Arts (tuition-free due to his father's service to the Academy).", "He graduated in 1900, and for graduation, his performance was the play ''The Arcady Trail''.", "In the audience was Charles Frohman, who would cast DeMille in his play ''Hearts are Trumps'', DeMille's Broadway debut.===1900–1912: theater=======Charles Frohman, Constance Adams, and David Belasco====Cecil B. DeMille began his career as an actor on the stage in the theatrical company of Charles Frohman in 1900.He debuted as an actor on February 21, 1900, in the play ''Hearts Are Trumps'' at New York's Garden Theater.", "In 1901, DeMille starred in productions of ''A Repentance'', ''To Have and to Hold'', and ''Are You a Mason?''", "At the age of 21, Cecil B. DeMille married Constance Adams on August 16, 1902, at Adams's father's home in East Orange, New Jersey.", "The wedding party was small.", "Beatrice DeMille's family was not in attendance, and Simon Louvish suggests that this was to conceal DeMille's partial Jewish heritage.", "Adams was 29 years old at the time of their marriage, eight years older than DeMille.", "They had met in a theater in Washington D.C. while they were both acting in ''Hearts Are Trumps''.They were sexually incompatible; according to DeMille, Adams was too \"pure\" to \"feel such violent and evil passions\".", "DeMille had more violent sexual preferences and fetishes than his wife.", "Adams allowed DeMille to have several long-term mistresses during their marriage as an outlet while maintaining an outward appearance of a faithful marriage.", "One of DeMille's affairs was with his screenwriter Jeanie MacPherson.", "Despite his reputation for extramarital affairs, DeMille did not like to have affairs with his stars, as he believed it would cause him to lose control as a director.", "He related a story that he maintained his self-control when Gloria Swanson sat on his lap, refusing to touch her.In 1902, he played a small part in ''Hamlet''.", "Publicists wrote that he became an actor in order to learn how direct and produce, but DeMille admitted that he became an actor in order to pay the bills.", "From 1904 to 1905, DeMille attempted to make a living as a stock theatre actor with his wife, Constance.", "DeMille made a 1905 reprise in ''Hamlet'' as Osric.", "In the summer of 1905, DeMille joined the stock cast at the Elitch Theatre in Denver, Colorado.", "He appeared in eleven of the fifteen plays presented that season, although all were minor roles.", "Maude Fealy would appear as the featured actress in several productions that summer and would develop a lasting friendship with DeMille.", "(He would later cast her in ''The Ten Commandments''.)", "His brother, William, was establishing himself as a playwright and sometimes invited DeMille to collaborate.", "DeMille and William collaborated on ''The Genius'', ''The Royal Mounted'', and ''After Five''.", "However, none of these were very successful; William deMille was most successful when he worked alone.", "DeMille and his brother at times worked with the legendary impresario David Belasco, who had been a friend and collaborator of their father.", "DeMille would later adapt Belasco's ''The Girl of the Golden West'', ''Rose of the Rancho'', and ''The Warrens of Virginia'' into films.", "DeMille was credited with creating the premise of Belasco's ''The Return of Peter Grimm''.", "''The Return of Peter Grimm'' sparked controversy, because Belasco had taken DeMille's unnamed screenplay, changed the characters, and named it ''The Return of Peter Grimm'', producing and presenting it as his own work.", "DeMille was credited in small print as \"based on an idea by Cecil DeMille\".", "The play was successful, and DeMille was distraught that his childhood idol had plagiarized his work.====Losing interest in theatre====DeMille performed on stage with actors whom he would later direct in films: Charlotte Walker, Mary Pickford, and Pedro de Cordoba.", "DeMille also produced and directed plays.", "His 1905 performance in ''The Prince Chap'' as the Earl of Huntington was well received by audiences.", "DeMille wrote a few of his own plays in-between stage performances, but his playwriting was not as successful.", "His first play was ''The Pretender-A Play in a Prologue and 4 Acts'' set in seventeenth century Russia.", "Another unperformed play he wrote was ''Son of the Winds'', a mythological Native American story.", "Life was difficult for DeMille and his wife as traveling actors; however, traveling allowed him to experience part of the United States he had not yet seen.", "DeMille sometimes worked with the director E. H. Sothern, who influenced DeMille's later perfectionism in his work.", "In 1907, due to a scandal with one of Beatrice's students, Evelyn Nesbit, the Henry de Mille School lost students.", "The school closed, and Beatrice filed for bankruptcy.", "DeMille wrote another play originally called ''Sergeant Devil May Care'', which was renamed ''The Royal Mounted''.", "He also toured with the Standard Opera Company, but there are few records to indicate DeMille's singing ability.", "DeMille had a daughter, Cecilia, on November 5, 1908, who would be his only biological child.", "In the 1910s, DeMille began directing and producing other writer's plays.DeMille was poor and struggled to find work.", "Consequently, his mother hired him for her agency The DeMille Play Company, and taught him how to be an agent and a playwright.", "Eventually, he became manager of the agency and later, a junior partner with his mother.", "In 1911, DeMille became acquainted with vaudeville producer Jesse Lasky when Lasky was searching for a writer for his new musical.", "He initially sought out William deMille.", "William had been a successful playwright, but DeMille was suffering from the failure of his plays ''The Royal Mounted'' and ''The Genius''.", "However, Beatrice introduced Lasky to DeMille instead.", "The collaboration of DeMille and Lasky produced a successful musical called ''California'', which opened in New York in January 1912.Another DeMille-Lasky production that opened in January 1912 was ''The Antique Girl''.", "DeMille found success in the spring of 1913, producing ''Reckless Age'' by Lee Wilson, a play about a high society girl wrongly accused of manslaughter starring Frederick Burton and Sydney Shields.", "However, changes in the theater rendered DeMille's melodramas obsolete before they were produced, and true theatrical success eluded him.", "He produced many flops.", "Having become disinterested in working in theatre, DeMille's passion for film was ignited when he watched the 1912 French film ''Les Amours de la reine Élisabeth''.===1913–1914: entering films===The Squaw Man'' (1914) full filmDesiring a change of scene, Cecil B. DeMille, Jesse Lasky, Sam Goldfish (later Samuel Goldwyn), and a group of East Coast businessmen created the Jesse L. Lasky Feature Play Company in 1913, over which DeMille became director-general.", "Lasky and DeMille were said to have sketched out the organization of the company on the back of a restaurant menu.", "As director-general, DeMille's job was to make the films.", "In addition to directing, DeMille was the supervisor and consultant for the first year of films made by the Lasky Feature Play Company.", "Sometimes, he directed scenes for other directors at the Feature Play Company in order to release films on time.", "Moreover, when he was busy directing other films, he would co-author other Lasky Company scripts as well as create screen adaptations that others directed.The Lasky Play Company sought out William deMille to join the company, but he rejected the offer because he did not believe there was any promise in a film career.", "When William found out that DeMille had begun working in the motion picture industry, he wrote DeMille a letter, disappointed that he was willing \"to throw away his future\" when he was \"born and raised in the finest traditions of the theater\".", "The Lasky Company wanted to attract high-class audiences to their films, so they began producing films from literary works.", "The Lasky Company bought the rights to the play ''The Squaw Man'' by Edwin Milton Royle and cast Dustin Farnum in the lead role.", "They offered Farnum a choice to have a quarter stock in the company (similar to William deMille) or $250 per week as salary.", "Farnum chose $250 per week.", "Already $15,000 in debt to Royle for the screenplay of ''The Squaw Man'', Lasky's relatives bought the $5,000 stock to save the Lasky Company from bankruptcy.", "With no knowledge of filmmaking, DeMille was introduced to observe the process at film studios.", "He was eventually introduced to Oscar Apfel, a stage director who had been a director with the Edison Company.On December 12, 1913, DeMille, his cast, and crew boarded a Southern Pacific train bound for Flagstaff via New Orleans.", "His tentative plan was to shoot a film in Arizona, but he felt that Arizona did not typify the Western look they were searching for.", "They also learned that other filmmakers were successfully shooting in Los Angeles, even in winter.", "He continued to Los Angeles.", "Once there, he chose not to shoot in Edendale, where many studios were, but in Hollywood.", "DeMille rented a barn to function as their film studio.", "Filming began on December 29, 1913, and lasted three weeks.", "Apfel filmed most of ''The Squaw Man'' due to DeMille's inexperience; however, DeMille learned quickly and was particularly adept at impromptu screenwriting as necessary.", "He made his first film run sixty minutes, as long as a short play.", "''The Squaw Man'' (1914), co-directed by Oscar Apfel, was a sensation, and it established the Lasky Company.", "This was the first feature-length film made in Hollywood.", "There were problems with the perforation of the film stock, and it was discovered the DeMille had brought a cheap British film perforator, which had punched in sixty-five holes per foot instead of the industry-standard of sixty-four.", "Lasky and DeMille convinced film pioneer Siegmund Lubin of the Lubin Manufacturing Company of Philadelphia to have his experienced technicians reperforate the film This was also the first American feature film; however, only by release date, as D. W. Griffith's ''Judith of Bethulia'' was filmed earlier than ''The Squaw Man'', but released later.", "Additionally, this was the only film in which DeMille shared director's credit with Oscar C.", "Apfel.", "''The Squaw Man'' was a success, which led to the eventual founding of Paramount Pictures and Hollywood becoming the \"film capital of the world\".", "The film grossed over ten times its budget after its New York premiere in February 1914.DeMille's next project was to aid Oscar Apfel in directing ''Brewster's Millions'', which was wildly successful.", "In December 1914, Constance Adams brought home John DeMille, a fifteen-month-old, whom the couple legally adopted three years later.", "Biographer Scott Eyman suggested that this may have been a result of Adams's recent miscarriage.===1915–1928: silent era=======Westerns, Paradise, and World War I====alt=Five well-dressed men seated or standing at various levelsCecil B. DeMille's second film credited exclusively to him was ''The Virginian''.", "This is the earliest of DeMille's films available in a quality, color-tinted video format.", "However, this version is actually a 1918 re-release.", "The first few years of the Lasky Company were spent in making films nonstop, literally writing the language of film.", "DeMille himself directed twenty films by 1915.The most successful films during the beginning of the Lasky Company were ''Brewster's Millions'' (co-directed by DeMille), ''Rose of the Rancho'', and ''The Ghost Breaker''.", "DeMille adapted Belasco's dramatic lighting techniques to film technology, mimicking moonlight with U.S. cinema's first attempts at \"motivated lighting\" in ''The Warrens of Virginia''.", "This was the first of few film collaborations with his brother William.", "They struggled to adapt the play from the stage to the set.", "After the film was shown, viewers complained that the shadows and lighting prevented the audience from seeing the actors' full faces, complaining that they would only pay half price.", "However, Sam Goldwyn realized that if they called it \"Rembrandt\" lighting, the audience would pay double the price.", "Additionally, because of DeMille's cordiality after the ''Peter Grimm'' incident, DeMille was able to rekindle his partnership with Belasco.", "He adapted several of Belasco's screenplays into film.DeMille's most successful film was ''The Cheat''; DeMille's direction in the film was acclaimed.", "In 1916, exhausted from three years of nonstop filmmaking, DeMille purchased land in the Angeles National Forest for a ranch that would become his getaway.", "He called this place, \"Paradise\", declaring it a wildlife sanctuary; no shooting of animals besides snakes was allowed.", "His wife did not like Paradise, so DeMille often brought his mistresses there with him, including actress Julia Faye.", "In addition to his Paradise, DeMille purchased a yacht in 1921, which he called ''The Seaward''.While filming ''The Captive'' in 1915, an extra, Bob Fleming, died on set when another extra failed to heed DeMille's orders to unload all guns for rehearsal.", "DeMille instructed the guilty man to leave town and would never reveal his name.", "Lasky and DeMille maintained the widow Fleming on the payroll; however, according to leading actor House Peters Sr., DeMille refused to stop production for the funeral of Fleming.", "Peters claimed that he encouraged the cast to attend the funeral with him anyway since DeMille would not be able to shoot the film without him.", "On July 19, 1916, the Jesse Lasky Feature Play Company merged with Adolph Zukor's Famous Players Film Company, becoming Famous Players–Lasky.", "Zukor became president with Lasky as the vice president.", "DeMille was maintained as director-general, and Goldwyn became chairman of the board.", "Goldwyn was later fired from Famous Players–Lasky due to frequent clashes with Lasky, DeMille, and Zukor.", "While on a European vacation in 1921, DeMille contracted rheumatic fever in Paris.", "He was confined to bed and unable to eat.", "His poor physical condition upon his return home affected the production of his 1922 film ''Manslaughter''.", "According to Richard Birchard, DeMille's weakened state during production may have led to the film being received as uncharacteristically substandard.During World War I, the Famous Players–Lasky organized a military company underneath the National Guard called the ''Home Guard'' made up of film studio employees with DeMille as captain.", "Eventually, the Guard was enlarged to a battalion and recruited soldiers from other film studios.", "They took time off weekly from film production to practice military drills.", "Additionally, during the war, DeMille volunteered for the Justice Department's Intelligence Office, investigating friends, neighbors, and others he came in contact with in connection with the Famous Players–Lasky.", "He volunteered for the Intelligence Office during World War II as well.", "Although DeMille considered enlisting in World War I, he stayed in the United States and made films.", "However, he did take a few months to set up a movie theater for the French front.", "Famous Players–Lasky donated the films.", "DeMille and Adams adopted Katherine Lester in 1920, whom Adams had found in the orphanage over which she was the director.", "In 1922, the couple adopted Richard deMille.====Scandalous dramas, Biblical epics, and departure from Paramount====Film started becoming more sophisticated and the subsequent films of the Lasky company were criticized for primitive and unrealistic set design.", "Consequently, Beatrice deMille introduced the Famous Players–Lasky to Wilfred Buckland, who DeMille had known from his time at the American Academy of Dramatic Arts, and he became DeMille's art director.", "William deMille reluctantly became a story editor.", "William deMille would later convert from theater to Hollywood and would spend the rest of his career as a film director.", "Throughout his career, DeMille would frequently remake his own films.", "In his first instance, in 1917, he remade ''The Squaw Man'' (1918), only waiting four years from the 1914 original.", "Despite its quick turnaround, the film was fairly successful.", "However, DeMille's second remake at MGM in 1931 would be a failure.After five years and thirty hit films, DeMille became the American film industry's most successful director.", "In the silent era, he was renowned for ''Male and Female'' (1919), ''Manslaughter'' (1922), ''The Volga Boatman'' (1926), and ''The Godless Girl'' (1928).", "DeMille's trademark scenes included bathtubs, lion attacks, and Roman orgies.", "Many of his films featured scenes in two-color Technicolor.", "In 1923, DeMille released a modern melodrama ''The Ten Commandments'', which was a significant change from his previous stint of irreligious films.", "The film was produced on a large budget of $600,000, the most expensive production at Paramount.", "This concerned the executives at Paramount; however, the film turned out to be the studio's highest-grossing film.", "It held the Paramount record for twenty-five years until DeMille broke the record again.alt=Sepia toned advertisement for \"For Better, For Worse\" with a headshot of DeMille at the topIn the early 1920s, scandal surrounded Paramount; religious groups and the media opposed portrayals of immorality in films.", "A censorship board called the Hays Code was established.", "DeMille's film ''The Affairs of Anatol'' came under fire.", "Furthermore, DeMille argued with Zukor over his extravagant and over-budget production costs.", "Consequently, DeMille left Paramount in 1924 despite having helped establish it.", "He joined the Producers Distributing Corporation.", "His first film in the new production company, DeMille Pictures Corporation, was ''The Road to Yesterday'' in 1925.He directed and produced four films on his own, working with Producers Distributing Corporation because he found front office supervision too restricting.", "Aside from ''The King of Kings,'' none of DeMille's films away from Paramount were successful.", "''The King of Kings'' established DeMille as \"master of the grandiose and of biblical sagas\".", "Considered at the time to be the most successful Christian film of the silent era, DeMille calculated that it had been viewed over 800 million times around the world.", "After the release of DeMille's ''The Godless Girl'', silent films in America became obsolete, and DeMille was forced to shoot a shoddy final reel with the new sound production technique.", "Although this final reel looked so different from the previous eleven reels that it appeared to be from another movie, according to Simon Louvish, the film is one of DeMille's strangest and most \"DeMillean\" film.The immense popularity of DeMille's silent films enabled him to branch out into other areas.", "The Roaring Twenties were the boom years and DeMille took full advantage, opening the Mercury Aviation Company, one of America's first commercial airlines.", "He was also a real estate speculator, an underwriter of political campaigns, and vice president of Bank of America.", "He was additionally vice president of the Commercial National Trust and Savings Bank in Los Angeles where he approved loans for other filmmakers.", "In 1916, DeMille purchased a mansion in Hollywood.", "Charlie Chaplin lived next door for a time, and after he moved, DeMille purchased the other house and combined the estates.===1929–1956: sound era=======MGM and return to Paramount====When \"talking pictures\" were invented in 1928, Cecil B. DeMille made a successful transition, offering his own innovations to the painful process; he devised a microphone boom and a soundproof camera blimp.", "He also popularized the camera crane.", "His first three sound films were produced at Metro-Goldwyn-Mayer.", "These three films, ''Dynamite'', ''Madame Satan'', and his 1931 remake of ''The Squaw Man'' were critically and financially unsuccessful.", "He had completely adapted to the production of sound film despite the film's poor dialogue.", "After his contract ended at MGM, he left, but no production studios would hire him.", "He attempted to create a guild of a half a dozen directors with the same creative desires called the Director's Guild.", "However, the idea failed due to lack of funding and commitment.", "Moreover, DeMille was audited by the Internal Revenue Service due to issues with his production company.", "This was, according to DeMille, the lowest point of his career.", "DeMille traveled abroad to find employment until he was offered a deal at Paramount.In 1932, DeMille returned to Paramount at the request of Lasky, bringing with him his own production unit.", "His first film back at Paramount, ''The Sign of the Cross'', was also his first success since leaving Paramount besides ''The King of Kings''.", "DeMille's return was approved by Zukor under the condition that DeMille not exceed his production budget of $650,000 for ''The Sign of the Cross''.", "Produced in eight weeks without exceeding budget, the film was financially successful.", "''The Sign of the Cross'' was the first film to integrate all cinematic techniques.", "The film was considered a \"masterpiece\" and surpassed the quality of other sound films of the time.", "DeMille followed this epic uncharacteristically with two dramas released in 1933 and 1934.", "''This Day and Age'' and ''Four Frightened People'' were box office disappointments, though ''Four Frightened People'' received good reviews.", "DeMille would stick to his large-budget spectaculars for the rest of his career.====Politics and ''Lux Radio Theatre''====alt=Full body photograph of DeMille wearing a blakc suit, holding a top hat in one hand and the CBS radio microphone in the otherCecil B. DeMille was outspoken about his strong Episcopalian integrity, but his private life included mistresses and adultery.", "DeMille was a conservative Republican activist, becoming more conservative as he aged.", "He was known as anti-union and worked to prevent the unionizing of film production studios.", "However, according to DeMille himself, he was not anti-union and belonged to a few unions himself.", "He said he was rather against union leaders such as Walter Reuther and Harry Bridges, whom he compared to dictators.", "He supported Herbert Hoover and in 1928 made his largest campaign donation to Hoover.", "DeMille also liked Franklin D. Roosevelt, however, finding him charismatic, tenacious, and intelligent and agreeing with Roosevelt's abhorrence of Prohibition.", "DeMille lent Roosevelt a car for his campaign for the 1932 United States presidential election and voted for him.", "However, he would never again vote for a Democratic candidate in a presidential election.From June 1, 1936, until January 22, 1945, Cecil DeMille hosted and directed ''Lux Radio Theatre'', a weekly digest of current feature films.", "Broadcast on the Columbia Broadcasting System (CBS) from 1935 to 1954, the ''Lux Radio'' show was one of the most popular weekly shows in the history of radio.", "While DeMille was host, the show had forty million weekly listeners, gaining DeMille an annual salary of $100,000.From 1936 to 1945, he produced, hosted, and directed all shows with the occasional exception of a guest director.", "He resigned from the ''Lux Radio'' show because he refused to pay a dollar to the American Federation of Radio Artists (AFRA) because he did not believe that any organization had the right to \"levy a compulsory assessment upon any member.", "\"DeMille sued the union for reinstatement but lost.", "He then appealed to the California Supreme Court and lost again.", "When the AFRA expanded to television, DeMille was banned from television appearances.", "Consequently, he formed the DeMille Foundation for Political Freedom in order to campaign for the right to work.", "He began presenting speeches across the United States for the next few years.", "DeMille's primary criticism was of closed shops, but later included criticism of communism and unions in general.", "The United States Supreme Court declined to review his case.", "Despite his loss, DeMille continued to lobby for the Taft–Hartley Act, which passed.", "This prohibited denying anyone the right to work if they refuse to pay a political assessment, however, the law did not apply retroactively.", "Consequently, DeMille's television and radio appearance ban lasted for the remainder of his life, though he was permitted to appear on radio or television to publicize a movie.", "William Keighley was his replacement.", "DeMille would never again work on radio.", "====Adventure films and dramatic spectacles====In 1939, DeMille's ''Union Pacific'' was successful through DeMille's collaboration with the Union Pacific Railroad.", "The Union Pacific gave DeMille access to historical data, early period trains, and expert crews, adding to the authenticity of the film.", "During pre-production of ''Union Pacific'', DeMille was dealing with his first serious health issue.", "In March 1938, he underwent a major emergency prostatectomy.", "He suffered from a post-surgery infection from which he nearly did not recover, citing streptomycin as his saving grace.", "The surgery caused him to suffer from sexual dysfunction for the rest of his life, according to some family members.", "Following his surgery and the success of ''Union Pacific'', in 1940, DeMille first used three-strip Technicolor in ''North West Mounted Police''.", "DeMille wanted to film in Canada; however, due to budget constraints, the film was instead shot in Oregon and Hollywood.", "Critics were impressed with the visuals but found the scripts dull, calling it DeMille's \"poorest Western\".", "Despite the criticism, it was Paramount's highest-grossing film of the year.", "Audiences liked its highly saturated color, so DeMille made no further black-and-white features.", "DeMille was anti-communist and abandoned a project in 1940 to film Ernest Hemingway's ''For Whom the Bell Tolls'' due to its communist themes, despite the fact he had already paid $100,000 for the rights to the novel.", "He was so eager to produce the film that he hadn't yet read the novel.", "He claimed he abandoned the project in order to complete a different project, but in reality, it was to preserve his reputation and avoid appearing reactionary.", "While concurrently filmmaking, he served in World War II at the age of sixty as his neighborhood air-raid warden.In 1942, DeMille worked with Jeanie MacPherson and brother William deMille in order to produce a film called ''Queen of Queens'', which was intended to be about Mary, mother of Jesus.", "After reading the screenplay, Daniel A. Lord warned DeMille that Catholics would find the film too irreverent, while non-Catholics would have considered the film Catholic propaganda.", "Consequently, the film was never made.", "Jeanie MacPherson would work as a scriptwriter for many of DeMille's films.", "In 1938, DeMille supervised the compilation of film ''Land of Liberty'' to represent the contribution of the American film industry to the 1939 New York World's Fair.", "DeMille used clips from his own films in ''Land of Liberty''.", "Though the film was not high-grossing, it was well-received, and DeMille was asked to shorten its running time to allow for more showings per day.", "MGM distributed the film in 1941 and donated profits to World War II relief charities.The Greatest Show on Earth'' (1952), the film for which he won the Academy Award for Best Picture|alt=Closeup of DeMille leaning on a setpieceIn 1942, DeMille released Paramount's most successful film, ''Reap the Wild Wind''.", "It was produced with a large budget and contained many special effects including an electronically operated giant squid.", "After working on ''Reap the Wild Wind'', in 1944, he was the master of ceremonies at the rally organized by David O. Selznick in the Los Angeles Coliseum in support of the Dewey–Bricker ticket as well as Governor Earl Warren of California.", "DeMille's subsequent film ''Unconquered'' (1947) had the longest running time (146 minutes), longest filming schedule (102 days), and largest budget ($5 million).", "The sets and effects were so realistic that 30 extras needed to be hospitalized due to a scene with fireballs and flaming arrows.", "It was commercially very successful.DeMille's next film, ''Samson and Delilah'' in 1949, became Paramount's highest-grossing film up to that time.", "A Biblical epic with sex, it was a characteristically DeMille film.", "Again, 1952's ''The Greatest Show on Earth'' became Paramount's highest-grossing film to that point.", "Furthermore, DeMille's film won the Academy Award for Best Picture and the Academy Award for Best Story.", "The film began production in 1949, Ringling Brothers-Barnum and Bailey were paid $250,000 for use of the title and facilities.", "DeMille toured with the circus while helping write the script.", "Noisy and bright, it was not well-liked by critics, but was a favorite among audiences.", "DeMille signed a contract with Prentice Hall publishers in August 1953 to publish an autobiography.", "DeMille would reminisce into a voice recorder, the recording would be transcribed, and the information would be organized in the biography based on the topic.", "Art Arthur also interviewed people for the autobiography.", "DeMille did not like the first draft of the biography, saying that he thought the person portrayed in the biography was an \"SOB\"; he said it made him sound too egotistical.", "Besides filmmaking and finishing his autobiography, DeMille was involved in other projects.", "In the early 1950s, DeMille was recruited by Allen Dulles and Frank Wisner to serve on the board of the anti-communist National Committee for a Free Europe, the public face of the organization that oversaw the Radio Free Europe service.", "In 1954, Secretary of the Air Force Harold E. Talbott asked DeMille for help in designing the cadet uniforms at the newly established United States Air Force Academy.", "DeMille's designs, most notably his design of the distinctive cadet parade uniform, won praise from Air Force and Academy leadership, were ultimately adopted, and are still worn by cadets.====Final works and unrealized projects====In 1952, DeMille sought approval for a lavish remake of his 1923 silent film ''The Ten Commandments''.", "He went before the Paramount board of directors, which was mostly Jewish-American.", "The members rejected his proposal, even though his last two films, ''Samson and Delilah'' and ''The Greatest Show on Earth'', had been record-breaking hits.", "Adolph Zukor convinced the board to change their minds on the grounds of morality.", "DeMille did not have an exact budget proposal for the project, and it promised to be the most costly in U.S. film history.", "Still, the members unanimously approved it.", "''The Ten Commandments'', released in 1956, was DeMille's final film.", "It was the longest (3 hours, 39 minutes) and most expensive ($13 million) film in Paramount history.", "Production of ''The Ten Commandments'' began in October 1954.The Exodus scene was filmed on-site in Egypt with the use of four Technicolor-VistaVision camera filming 12,000 people.", "They continued filming in 1955 in Paris and Hollywood on 30 different sound stages.", "They were even required to expand to RKO sound studios for filming.", "Post-production lasted a year, and the film premiered in Salt Lake City.", "Nominated for an Academy Award for Best Picture, it grossed over $80 million, which surpassed the gross of ''The Greatest Show on Earth'' and every other film in history, except for ''Gone with the Wind''.", "A unique practice at the time, DeMille offered ten percent of his profit to the crew.On November 7, 1954, while in Egypt filming the Exodus sequence for ''The Ten Commandments'', DeMille (who was seventy-three) climbed a ladder to the top of the massive Per Rameses set and suffered a serious heart attack.", "Despite the urging of his associate producer, DeMille wanted to return to the set right away.", "DeMille developed a plan with his doctor to allow him to continue directing while reducing his physical stress.", "Although DeMille completed the film, his health was diminished by several more heart attacks.", "His daughter Cecilia took over as director as DeMille sat behind the camera with Loyal Griggs as the cinematographer.", "This film would be his last.", "Due to his frequent heart attacks, DeMille asked his son-in-law, actor Anthony Quinn, to direct a remake of his 1938 film ''The Buccaneer''.", "DeMille served as executive producer, overseeing producer Henry Wilcoxon.", "Despite a cast led by Charlton Heston and Yul Brynner, the 1958 film ''The Buccaneer'' was a disappointment.", "DeMille attended the Santa Barbara premiere of ''The Buccaneer'' in December 1958.DeMille was unable to attend the Los Angeles premiere of ''The Buccaneer''.", "In the months before his death, DeMille was researching a film biography of Robert Baden-Powell, the founder of the Scout Movement.", "DeMille asked David Niven to star in the film, but it was never made.", "DeMille also was planning a film about the space race as well as another biblical epic about the Book of Revelation.", "DeMille's autobiography was mostly completed by the time DeMille died and was published in November 1959.====Death====alt=Two large white crypts next to each other in a cememtery Cecil B. DeMille suffered a series of heart attacks from June 1958 to January 1959, and died on January 21, 1959, following an attack.", "DeMille's funeral was held on January 23 at St. Stephen's Episcopal Church.", "He was entombed at the Hollywood Memorial Cemetery (now known as Hollywood Forever).", "After his death, notable news outlets such as ''The New York Times'', the ''Los Angeles Times'', and ''The Guardian'' honored DeMille as \"pioneer of movies\", \"the greatest creator and showman of our industry\", and \"the founder of Hollywood\".", "DeMille left his multi-million dollar estate in Los Feliz, Los Angeles, in Laughlin Park to his daughter Cecilia because his wife had dementia and was unable to care for an estate.", "She would die one year later.", "His personal will drew a line between Cecilia and his three adopted children, with Cecilia receiving a majority of DeMille's inheritance and estate.", "The other three children were surprised by this, as DeMille did not treat the children differently in life.", "Cecilia lived in the house for many years until her death in 1984, but the house was auctioned by his granddaughter Cecilia DeMille Presley who also lived there in the late 1980s." ], [ "Filmmaking", "===Influences===DeMille believed his first influences to be his parents, Henry and Beatrice DeMille.", "His playwright father introduced him to the theater at a young age.", "Henry was heavily influenced by the work of Charles Kingsley, whose ideas trickled down to DeMille.", "DeMille noted that his mother had a \"high sense of the dramatic\" and was determined to continue the artistic legacy of her husband after he died.", "Beatrice became a play broker and author's agent, influencing DeMille's early life and career.", "DeMille's father worked with David Belasco who was a theatrical producer, impresario, and playwright.", "Belasco was known for adding realistic elements in his plays such as real flowers, food, and aromas that could transport his audiences into the scenes.", "While working in theatre, DeMille used real fruit trees in his play ''California'', as influenced by Belasco.", "Similar to Belasco, DeMille's theatre revolved around entertainment rather than artistry.", "Generally, Belasco's influence of DeMille's career can be seen in DeMille's showmanship and narration.", "E. H. Sothern's early influence on DeMille's work can be seen in DeMille's perfectionism.", "DeMille recalled that one of the most influential plays he saw was ''Hamlet'', directed by Sothern.===Method===bookplate from his libraryDeMille's filmmaking process always began with extensive research.", "Next, he would work with writers to develop the story that he was envisioning.", "Then, he would help writers construct a script.", "Finally, he would leave the script with artists and allow them to create artistic depictions and renderings of each scene.", "Plot and dialogue were not a strong point of DeMille's films.", "Consequently, he focused his efforts on his films' visuals.", "He worked with visual technicians, editors, art directors, costume designers, cinematographers, and set carpenters in order to perfect the visual aspects of his films.", "With his editor, Anne Bauchens, DeMille used editing techniques to allow the visual images to bring the plot to climax rather than dialogue.", "DeMille had large and frequent office conferences to discuss and examine all aspects of the working film including story-boards, props, and special effects.DeMille rarely gave direction to actors; he preferred to \"office-direct\", where he would work with actors in his office, going over characters and reading through scripts.", "Any problems on the set were often fixed by writers in the office rather than on the set.", "DeMille did not believe a large movie set was the place to discuss minor character or line issues.", "DeMille was particularly adept at directing and managing large crowds in his films.", "Martin Scorsese recalled that DeMille had the skill to maintain control of not only the lead actors in a frame but the many extras in the frame as well.", "DeMille was adept at directing \"thousands of extras\", and many of his pictures include spectacular set pieces: the toppling of the pagan temple in ''Samson and Delilah''; train wrecks in ''The Road to Yesterday'', ''Union Pacific'' and ''The Greatest Show on Earth''; the destruction of an airship in ''Madam Satan''; and the parting of the Red Sea in both versions of ''The Ten Commandments''.Samson and Delilah'' (1949)|alt=Large pagan temple film set with a large idol in the middle, and surrounded by hieroglyphics and red draperyIn his early films, DeMille experimented with photographic light and shade, which created dramatic shadows instead of glare.", "His specific use of lighting, influenced by his mentor David Belasco, was for the purpose of creating \"striking images\" and heightening \"dramatic situations\".", "DeMille was unique in using this technique.", "In addition to his use of volatile and abrupt film editing, his lighting and composition were innovative for the time period as filmmakers were primarily concerned with a clear, realistic image.", "Another important aspect of DeMille's editing technique was to put the film away for a week or two after an initial edit in order to re-edit the picture with a fresh mind.", "This allowed for the rapid production of his films in the early years of the Lasky Company.", "The cuts were sometimes rough, but the movies were always interesting.DeMille often edited in a manner that favored psychological space rather than physical space through his cuts.", "In this way, the characters' thoughts and desires are the visual focus rather than the circumstances regarding the physical scene.", "As DeMille's career progressed, he increasingly relied on artist Dan Sayre Groesbeck's concept, costume, and storyboard art.", "Groesbeck's art was circulated on set to give actors and crew members a better understanding of DeMille's vision.", "His art was even shown at Paramount meetings when pitching new films.", "DeMille adored the art of Groesbeck, even hanging it above his fireplace, but film staff found it difficult to convert his art into three-dimensional sets.", "As DeMille continued to rely on Groesbeck, the nervous energy of his early films transformed into more steady compositions of his later films.", "While visually appealing, this made the films appear more old-fashioned.Composer Elmer Bernstein described DeMille as \"sparing no effort\" when filmmaking.", "Bernstein recalled that DeMille would scream, yell, or flatter—whatever it took to achieve the perfection he required in his films.", "DeMille was painstakingly attentive to details on set and was as critical of himself as he was of his crew.", "Costume designer Dorothy Jeakins, who worked with DeMille on ''The Ten Commandments'' (1956), said that he was skilled in humiliating people.", "Jeakins admitted that she received quality training from him, but that it was necessary to become a perfectionist on a DeMille set to avoid being fired.", "DeMille had an authoritarian persona on set; he required absolute attention from the cast and crew.", "He had a band of assistants who catered to his needs.", "He would speak to the entire set, sometimes enormous with countless numbers of crew members and extras, via a microphone to maintain control of the set.", "He was disliked by many inside and outside of the film industry for his cold and controlling reputation.DeMille was known for autocratic behavior on the set, singling out and berating extras who were not paying attention.", "Many of these displays were thought to be staged, however, as an exercise in discipline.", "He despised actors who were unwilling to take physical risks, especially when he had first demonstrated that the required stunt would not harm them.", "This occurred with Victor Mature in ''Samson and Delilah''.", "Mature refused to wrestle Jackie the Lion, even though DeMille had just tussled with the lion, proving that he was tame.", "DeMille told the actor that he was \"one hundred percent yellow\".", "Paulette Goddard's refusal to risk personal injury in a scene involving fire in ''Unconquered'' cost her DeMille's favor and a role in ''The Greatest Show on Earth''.", "DeMille did receive help in his films, notably from Alvin Wyckoff, who shot forty-three of DeMille's films; brother William deMille who would occasionally serve as his screenwriter; and Jeanie Macpherson, who served as DeMille's exclusive screenwriter for fifteen years; and Eddie Salven, DeMille's favorite assistant director.DeMille made stars of unknown actors: Gloria Swanson, Bebe Daniels, Rod La Rocque, William Boyd, Claudette Colbert, and Charlton Heston.", "He also cast established stars such as Gary Cooper, Robert Preston, Paulette Goddard and Fredric March in multiple pictures.", "DeMille cast some of his performers repeatedly, including Henry Wilcoxon, Julia Faye, Joseph Schildkraut, Ian Keith, Charles Bickford, Theodore Roberts, Akim Tamiroff, and William Boyd.", "DeMille was credited by actor Edward G. Robinson with saving his career following his eclipse in the Hollywood blacklist.===Style and themes===Cecil B. DeMille's film production career evolved from critically significant silent films to financially significant sound films.", "He began his career with reserved yet brilliant melodramas; from there, his style developed into marital comedies with outrageously melodramatic plots.", "In order to attract a high-class audience, DeMille based many of his early films on stage melodramas, novels, and short stories.", "He began the production of epics earlier in his career until they began to solidify his career in the 1920s.", "By 1930, DeMille had perfected his film style of mass-interest spectacle films with Western, Roman, or Biblical themes.", "DeMille was often criticized for making his spectacles too colorful and for being too occupied with entertaining the audience rather than accessing the artistic and auteur possibilities that film could provide.", "However, others interpreted DeMille's work as visually impressive, thrilling, and nostalgic.", "Along the same lines, critics of DeMille often qualify him by his later spectacles and fail to consider several decades of ingenuity and energy that defined him during his generation.", "Throughout his career, he did not alter his films to better adhere to contemporary or popular styles.", "Actor Charlton Heston admitted DeMille was, \"terribly unfashionable\" and Sidney Lumet called DeMille, \"the cheap version of D.W. Griffith\", adding that DeMille, \"didn't have...an original thought in his head\", though Heston added that DeMille was much more than that.alt=DeMille posing on a chair with a pen in handAccording to Scott Eyman, DeMille's films were at the same time masculine and feminine due to his thematic adventurousness and his eye for the extravagant.", "DeMille's distinctive style can be seen through camera and lighting effects as early as ''The Squaw Man'' with the use of daydream images; moonlight and sunset on a mountain; and side-lighting through a tent flap.", "In the early age of cinema, DeMille differentiated the Lasky Company from other production companies due to the use of dramatic, low-key lighting they called \"Lasky lighting\" and marketed as \"Rembrandt lighting\" to appeal to the public.", "DeMille achieved international recognition for his unique use of lighting and color tint in his film ''The Cheat''.", "DeMille's 1956 version of ''The Ten Commandments'', according to director Martin Scorsese, is renowned for its level of production and the care and detail that went into creating the film.", "He stated that ''The Ten Commandments'' was the final culmination of DeMille's style.DeMille was interested in art and his favorite artist was Gustave Doré; DeMille based some of his most well-known scenes on the work of Doré.", "DeMille was the first director to connect art to filmmaking; he created the title of \"art director\" on the film set.", "DeMille was also known for his use of special effects without the use of digital technology.", "Notably, DeMille had cinematographer John P. Fulton create the parting of the Red Sea scene in his 1956 film ''The Ten Commandments'', which was one of the most expensive special effects in film history, and has been called by Steven Spielberg \"the greatest special effect in film history\".", "The actual parting of the sea was created by releasing 360,000 gallons of water into a huge water tank split by a U-shaped trough, overlaying it with a film of a giant waterfall that was built on the Paramount backlot, and playing the clip backward.Aside from his Biblical and historical epics, which are concerned with how man relates to God, some of DeMille's films contained themes of \"neo-naturalism\", which portray the conflict between the laws of man and the laws of nature.", "Although he is known for his later \"spectacular\" films, his early films are held in high regard by critics and film historians.", "DeMille discovered the possibilities of the \"bathroom\" or \"boudoir\" in the film without being \"vulgar\" or \"cheap\".", "DeMille's films ''Male and Female'', ''Why Change Your Wife?", "'', and ''The Affairs of Anatol'' can be retrospectively described as high camp and are categorized as \"early DeMille films\" due to their particular style of production and costume and set design.", "However, his earlier films ''The Captive'', ''Kindling'', ''Carmen'', and ''The Whispering Chorus'' are more serious films.", "It is difficult to typify DeMille's films into one specific genre.", "His first three films were Westerns, and he filmed many Westerns throughout his career.", "However, throughout his career, he filmed comedies, periodic and contemporary romances, dramas, fantasies, propaganda, Biblical spectacles, musical comedies, suspense, and war films.", "At least one DeMille film can represent each film genre.", "DeMille produced the majority of his films before the 1930s, and by the time sound films were invented, film critics saw DeMille as antiquated, with his best filmmaking years behind him.DeMille's films contained many similar themes throughout his career.", "However, the films of his silent era were often thematically different from the films of his sound era.", "His silent-era films often included the \"battle of the sexes\" theme due to the era of women's suffrage and the enlarging role of women in society.", "Moreover, before his religious-themed films, many of his silent era films revolved around \"husband-and-wife-divorce-and-remarry satires\", considerably more adult-themed.", "According to Simon Louvish, these films reflected DeMille's inner thoughts and opinions about marriage and human sexuality.", "Religion was a theme that DeMille returned to throughout his career.", "Of his seventy films, five revolved around stories of the Bible and the New Testament; however many others, while not direct retellings of Biblical stories, had themes of faith and religious fanaticism in films such as ''The Crusades'' and ''The Road to Yesterday''.", "Western and frontier American were also themes that DeMille returned to throughout his career.", "His first several films were Westerns, and he produced a chain of westerns during the sound era.", "Instead of portraying the danger and anarchy of the West, he portrayed the opportunity and redemption found in Western America.", "Another common theme in DeMille's films is the reversal of fortune and the portrayal of the rich and the poor, including the war of the classes and man versus society conflicts such as in ''The Golden Chance'' and ''The Cheat''.", "In relation to his own interests and sexual preferences, sadomasochism was a minor theme present in some of his films.", "Another minor characteristic of DeMille's films include train crashes, which can be found in several of his films." ], [ "Legacy", "alt=Actor playing Moses wearing a red robe and holding his arms out to the sides with dark clouds behind himKnown as the father of the Hollywood motion picture industry, Cecil B. DeMille made 70 films including several box-office hits.", "DeMille is one of the more commercially successful film directors in history, with his films before the release of ''The Ten Commandments'' estimated to have grossed $650  million worldwide.", "Adjusted for inflation, DeMille's remake of ''The Ten Commandments'' is the eighth highest-grossing film in the world.According to Sam Goldwyn, critics did not like DeMille's films, but the audiences did, and \"they have the final word\".", "Similarly, scholar David Blanke, argued that DeMille had lost the respect of his colleagues and film critics by his late film career.", "However, his final films maintained that DeMille was still respected by his audiences.", "Five of DeMille's films were the highest-grossing films at the year of their release, with only Spielberg topping him with six of his films as the highest-grossing films of the year.", "DeMille's highest-grossing films include: ''The Sign of the Cross'' (1932), ''Unconquered'' (1947), ''Samson and Delilah'' (1949), ''The Greatest Show on Earth'' (1952), and ''The Ten Commandments'' (1956).", "Director Ridley Scott has been called \"the Cecil B. DeMille of the digital era\" due to his classical and medieval epics.Despite his box-office success, awards, and artistic achievements, DeMille has been dismissed and ignored by critics both during his life and posthumously.", "He was consistently criticized for producing shallow films without talent or artistic care.", "Compared to other directors, few film scholars have taken the time to academically analyze his films and style.", "During the French New Wave, critics began to categorize certain filmmakers as auteurs such as Howard Hawks, John Ford, and Raoul Walsh.", "DeMille was omitted from the list, thought to be too unsophisticated and antiquated to be considered an auteur.", "However, Simon Louvish wrote \"he was the complete master and auteur of his films\", and Anton Kozlovic called him the \"unsung American auteur\".", "Andrew Sarris, a leading proponent of the auteur theory, ranked DeMille highly as an auteur in the \"Far Side of Paradise\", just below the \"Pantheon\".", "Sarris added that despite the influence of the styles of contemporary directors throughout his career, DeMille's style remained unchanged.", "Robert Birchard wrote that one could argue the auteurship of DeMille on the basis that DeMille's thematic and visual style remained consistent throughout his career.", "However, Birchard acknowledged that Sarris's point was more likely that DeMille's style was behind the development of film as an art form.", "Meanwhile, Sumiko Higashi sees DeMille as \"not only a figure who was shaped and influenced by the forces of his era but as a filmmaker who left his own signature on the culture industry.\"", "The critic Camille Paglia has called ''The Ten Commandments'' one of the ten greatest films of all time.alt=DeMille on a stand, holding a megaphone, giving commands to crew members which surround him and several film camerasDeMille was one of the first directors to become a celebrity in his own right.", "He cultivated the image of the omnipotent director, complete with megaphone, riding crop, and jodhpurs.", "He was known for his unique working wardrobe, which included riding boots, riding pants, and soft, open necked shirts.", "Joseph Henabery recalled that DeMille looked like \"a king on a throne surrounded by his court\" while directing films on a camera platform.DeMille was liked by some of his fellow directors and disliked by others, though his actual films were usually dismissed by his peers as a vapid spectacle.", "Director John Huston intensely disliked both DeMille and his films.", "\"He was a thoroughly bad director\", Huston said.", "\"A dreadful showoff.", "Terrible.", "To diseased proportions.\"", "Said fellow director William Wellman: \"Directorially, I think his pictures were the most horrible things I've ever seen in my life.", "But he put on pictures that made a fortune.", "In that respect, he was better than any of us.\"", "Producer David O. Selznick wrote: \"There has appeared only one Cecil B. DeMille.", "He is one of the most extraordinarily able showmen of modern times.", "However much I may dislike some of his pictures, it would be very silly of me, as a producer of commercial motion pictures, to demean for an instant his unparalleled skill as a maker of mass entertainment.\"", "Salvador Dalí wrote that DeMille, Walt Disney, and the Marx Brothers were \"the three great American Surrealists\".", "DeMille appeared as himself in numerous films, including the MGM comedy ''Free and Easy''.", "He often appeared in his coming-attraction trailers and narrated many of his later films, even stepping on screen to introduce ''The Ten Commandments''.", "DeMille was immortalized in Billy Wilder's ''Sunset Boulevard'' when Gloria Swanson spoke the line: \"All right, Mr. DeMille.", "I'm ready for my close-up.\"", "DeMille plays himself in the film.", "DeMille's reputation had a renaissance in the 2010s.As a filmmaker, DeMille was the aesthetic inspiration of many directors and films due to his early influence during the crucial development of the film industry.", "DeMille's early silent comedies influenced the comedies of Ernst Lubitsch and Charlie Chaplin's ''A Woman of Paris''.", "Additionally, DeMille's epics such as ''The Crusades'' influenced Sergei Eisenstein's ''Alexander Nevsky''.", "Moreover, DeMille's epics inspired directors such as Howard Hawks, Nicholas Ray, Joseph L. Mankiewicz, and George Stevens to try producing epics.", "Cecil B. DeMille has influenced the work of several well-known directors.", "Alfred Hitchcock cited DeMille's 1921 film ''Forbidden Fruit'' as an influence of his work and one of his top ten favorite films.", "DeMille has influenced the careers of many modern directors.", "Martin Scorsese cited ''Unconquered'', ''Samson and Delilah'', and ''The Greatest Show on Earth'' as DeMille films that have imparted lasting memories on him.", "Scorsese said he had viewed ''The Ten Commandments'' forty or fifty times.", "Famed director Steven Spielberg stated that DeMille's ''The Greatest Show on Earth'' was one of the films that influenced him to become a filmmaker.", "Furthermore, DeMille influenced about half of Spielberg's films, including ''War of the Worlds''.", "''The Ten Commandments'' inspired DreamWorks Animation's later film about Moses, ''The Prince of Egypt''.", "As one of the establishing members of Paramount Pictures and co-founder of Hollywood, DeMille had a role in the development of the film industry.", "Consequently, the name \"DeMille\" has become synonymous with filmmaking.Publicly Episcopalian, DeMille drew on his Christian and Jewish ancestors to convey a message of tolerance.", "DeMille received more than a dozen awards from Christian and Jewish religious and cultural groups, including B'nai B'rith.", "However, not everyone received DeMille's religious films favorably.", "DeMille was accused of antisemitism after the release of ''The King of Kings'', and director John Ford despised DeMille for what he saw as \"hollow\" biblical epics meant to promote DeMille's reputation during the politically turbulent 1950s.", "In response to the claims, DeMille donated some of the profits from ''The King of Kings'' to charity.", "In the 2012 ''Sight & Sound'' poll, both DeMille's ''Samson and Delilah'' and 1923 version of ''The Ten Commandments'' received votes, but did not make the top 100 films.", "Although many of DeMille's films are available on DVD and Blu-ray release, only 20 of his silent films are commercially available on DVD ===Commemoration and tributes===The Lasky-DeMille Barn was the place of origin of Paramount Pictures and the location in which ''The Squaw Man'' (1913) was filmed.", "It became the Hollywood Heritage Museum in 1985.|alt=Yellow, house-like barn with a large white museum signThe original Lasky-DeMille Barn in which ''The Squaw Man'' was filmed was converted into a museum named the \"Hollywood Heritage Museum\".", "It opened on December 13, 1985, and features some of DeMille's personal artifacts.", "The Lasky-DeMille Barn was dedicated as a California historical landmark in a ceremony on December 27, 1956; DeMille was the keynote speaker.", "It was listed on the National Register of Historic Places in 2014.The Dunes Center in Guadalupe, California, contains an exhibition of artifacts uncovered in the desert near Guadalupe from DeMille's set of his 1923 version of ''The Ten Commandments'', known as the \"Lost City of Cecil B. DeMille\".", "Donated by the Cecil B. DeMille Foundation in 2004, the moving image collection of Cecil B. DeMille is held at the Academy Film Archive and includes home movies, outtakes, and never-before-seen test footage.In summer 2019, The Friends of the Pompton Lakes Library hosted a Cecil B DeMille film festival to celebrate DeMille's achievements and connection to Pompton Lakes.", "They screened four of his films at Christ Church, where DeMille and his family attended church when they lived there.", "Two schools have been named after him: Cecil B. DeMille Middle School, in Long Beach, California, which was closed and demolished in 2010 to make way for a new high school; and Cecil B. DeMille Elementary School in Midway City, California.", "The former film building at Chapman University in Orange, California, is named in honor of DeMille.", "During the Apollo 11 mission, Buzz Aldrin referred to himself in one instance as \"Cecil B. DeAldrin\", as a humorous nod to DeMille.", "The title of the 2000 John Waters film ''Cecil B. Demented'' alludes to DeMille.DeMille's legacy is maintained by his granddaughter Cecilia DeMille Presley who serves as the president of the Cecil B. DeMille Foundation, which strives to support higher education, child welfare, and film in Southern California.", "In 1963, the Cecil B. DeMille Foundation donated the \"Paradise\" ranch to the Hathaway Foundation, which cares for emotionally disturbed and abused children.", "A large collection of DeMille's materials including scripts, storyboards, and films resides at Brigham Young University in L. Tom Perry Special Collections." ], [ "Awards and recognition", "Cecil B. DeMille received many awards and honors, especially later in his career.", "DeMille’s block in the forecourt of Grauman's Chinese Theatre.In August 1941, DeMille was honored with a block in the forecourt of Grauman's Chinese Theatre.The American Academy of Dramatic Arts honored DeMille with an Alumni Achievement Award in 1958.alt=DeMille standing at a graduation ceremony in graduation robes among others sitting and applaudingIn 1957, DeMille gave the commencement address for the graduation ceremony of Brigham Young University, wherein he received an honorary Doctorate of Letter degree.", "Additionally, in 1958, he received an honorary Doctorate of Law degree from Temple University.From the film industry, DeMille received the Irving G. Thalberg Memorial Award at the Academy Awards in 1953, and a Lifetime Achievement Award from the Directors Guild of America Award the same year.", "In the same ceremony, DeMille received a nomination from Directors Guild of America Award for Outstanding Directorial Achievement in Motion Pictures for ''The Greatest Show on Earth''.", "In 1952, DeMille was awarded the first Cecil B. DeMille Award at the Golden Globes.", "An annual award, the Golden Globe's Cecil B. DeMille Award recognizes lifetime achievement in the film industry.", "For his contribution to the motion picture and radio industry, DeMille has two stars on the Hollywood Walk of Fame.", "The first, for radio contributions, is located at 6240 Hollywood Blvd.", "The second star is located at 1725 Vine Street.DeMille received two Academy Awards: an Honorary Award for \"37 years of brilliant showmanship\" in 1950 and a Best Picture award in 1953 for ''The Greatest Show on Earth''.", "DeMille received a Golden Globe Award for Best Director and was additionally nominated for the Best Director category at the 1953 Academy Awards for the same film.", "He was further nominated in the Best Picture category for ''The Ten Commandments'' at the 1957 Academy Awards.", "DeMille's ''Union Pacific'' received a Palme d'Or in retrospect at the 2002 Cannes Film Festival.Two of DeMille's films have been selected for preservation in the National Film Registry by the United States Library of Congress: ''The Cheat'' (1915) and ''The Ten Commandments'' (1956)." ], [ "Filmography", "Cecil B. DeMille made 70 features.", "52 of his features are silent films.", "The first 24 of his silent films were made in the first three years of his career (1913–1916).", "Eight of his films were \"epics\" with five of those classified as \"Biblical\".", "Six of DeMille's films—''The Arab'', ''The Wild Goose Chase'', ''The Dream Girl'', ''The Devil-Stone'', ''We Can't Have Everything'', and ''The Squaw Man'' (1918)—were destroyed by nitrate decomposition, and are considered lost.", "''The Ten Commandments'' is broadcast every Saturday at Passover in the United States on the ABC Television Network.===Directed features===Filmography obtained from ''Fifty Hollywood Directors''.", "'''Silent films''''''Sound films'''===Directing or producing credit===These films represent those which DeMille produced or assisted in directing, credited or uncredited.", "* ''Brewster's Millions'' (1914, lost)* ''The Master Mind'' (1914)* ''The Only Son'' (1914, lost)* ''The Man on the Box'' (1914)* ''The Ghost Breaker'' (1914, lost)* ''After Five'' (1915)* ''Nan of Music Mountain'' (1917)* ''Chicago'' (1927, Producer)* ''When Worlds Collide'' (1951, executive producer)* ''The War of the Worlds'' (1953, executive producer)* ''The Buccaneer'' (1958, producer)===Acting and cameos===DeMille frequently made cameos as himself in other Paramount films.", "Additionally, he often starred in prologues and special trailers that he created for his films, having an opportunity to personally address the audience." ], [ "Explanatory notes" ], [ "Citations" ], [ "General sources", "* * * * * * * * * * * * * * * Orrison, Katherine.", "''Written in Stone: Making Cecil B. DeMille's Epic, The Ten Commandments''.", "New York: Vestal Press, 1990..* * * * *" ], [ "External links", "* by the Cecil B. DeMille Foundation* * * * * Cecil B. DeMille at Virtual History* Cecil B. DeMille's Early Films' Costs and Grosses by David Pierce* Silent Film Bookshelf===Archival materials===* Cecil B. DeMille papers, Vault MSS 1400, L. Tom Perry Special Collections, Harold B. Lee Library, Brigham Young University, DeMille's personal and business papers including correspondence, audio, and video recordings, financial ledgers, and memorabilia* Other collections related to DeMille at the L. Tom Perry Special Collections, Harold B. Lee Library, Brigham Young University* The Mary Roberts Rinehart Papers, Vault SC.1958.03, ULS Special Collections, University of Pittsburgh Library, includes conversations with DeMille about her plays" ] ]
wikipedia
[ [ "Chinese Islamic cuisine" ], [ "Introduction", "'''Chinese Islamic cuisine''' consists of variations of regionally popular foods that are typical of Han Chinese cuisine, in particular to make them halal.", "Dishes borrow ingredients from Middle Eastern, Turkic, and South Asian cuisines, notably mutton and spices.", "Much like other northern Chinese cuisines, Chinese Islamic cuisine uses wheat noodles as the staple, rather than rice.", "Chinese Islamic dishes include clear-broth beef noodle soup and ''chuanr''.The Hui (ethnic Chinese Muslims), Bonan, Dongxiang, Salar, and Uyghurs of China, as well as the Dungans of Central Asia and the Panthays of Burma, collectively contribute to Chinese Islamic cuisine." ], [ "History", "A halal meat store in Hankou, 1934 to 1935Due to the large Muslim population in Western China, many Chinese restaurants cater to or are run by Muslims.", "Northern Chinese Islamic cuisine originated in China proper.", "It is heavily influenced by Beijing cuisine, with nearly all cooking methods identical and differs only in material due to religious restrictions.", "As a result, northern Islamic cuisine is often included in home Beijing cuisine though seldom in east coast restaurants.During the Yuan dynasty, halal and kosher methods of slaughtering animals and preparing food was banned and forbidden by the Mongol emperors, starting with Genghis Khan who banned Muslims and Jews from slaughtering their animals their own way and made them follow the Mongol method.Among all the subject alien peoples only the Hui-hui say \"we do not eat Mongol food.\"", "Cinggis Qa'an replied: \"By the aid of heaven we have pacified you; you are our slaves.", "Yet you do not eat our food or drink.", "How can this be right?\"", "He thereupon made them eat.", "\"If you slaughter sheep, you will be considered guilty of a crime.\"", "He issued a regulation to that effect ...", "In 1279/1280 under Qubilai all the Muslims say: “if someone else slaughters the animal we do not eat.\"", "Because the poor people are upset by this, from now on, Musuluman Muslim Huihui and Zhuhu Jewish Huihui, no matter who kills the animal will eat it and must cease slaughtering sheep themselves, and cease the rite of circumcision.Traditionally, there is a distinction between Northern and Southern Chinese Islamic cuisine despite both using lamb and mutton.", "Northern Chinese Islamic cuisine relies heavily on beef, but rarely ducks, geese, shrimp or seafood, while southern Islamic cuisine is the reverse.", "The reason for this difference is due to availability of the ingredients.", "Oxen have been long used for farming and Chinese governments have frequently strictly prohibited the slaughter of oxen for food.", "However, due to the geographic proximity of the northern part of China to minority-dominated regions that were not subjected to such restrictions, beef could be easily purchased and transported to Northern China.", "At the same time, ducks, geese and shrimp are rare in comparison to Southern China due to the arid climate of Northern China.", "Shrimp is regarded as makruh (hated) for consumption in the Hanafi madhhab that Hui adhere to although Hanafis like Bengalis make exceptions and consume it regularly.An Islamic fast food restaurant at Shanghai ExpoA Chinese Islamic restaurant () can be similar to a Mandarin restaurant with the exception that there is no pork on the menu and the dishes are primarily noodle/soup based.In most major eastern cities in China, there are very limited Islamic/Halal restaurants, which are typically run by migrants from Western China (e.g., Uyghurs).", "They primarily offer inexpensive noodle soups only.", "These restaurants are typically decorated with Islamic motifs such as pictures of Islamic rugs and Arabic writing.Another difference is that lamb and mutton dishes are more commonly available than in other Chinese restaurants, due to the greater prevalence of these meats in the cuisine of Western Chinese regions.", "(Refer to image 1.", ")Other Muslim ethnic minorities like the Bonan, Dongxiang, Salar and Tibetan Muslims have their own cuisines as well.", "Dongxiang people operate their own restaurants serving their cuisine.Many cafeterias (canteens) at Chinese universities have separate sections or dining areas for Muslim students (Hui or Western Chinese minorities), typically labeled \"qingzhen\".", "Student ID cards sometimes indicate whether a student is Muslim and will allow access to these dining areas or will allow access on special occasions such as the Eid feast following Ramadan.Several Hui restaurants serving Chinese Islamic cuisine exist in Los Angeles.", "San Francisco, despite its huge number of Chinese restaurants, appears to have only one whose cuisine would qualify as halal.Many Chinese Hui Muslims who moved from Yunnan to Burma (Myanmar) are known as Panthays operate restaurants and stalls serving Chinese Islamic cuisine such as noodles.", "Chinese Hui Muslims from Yunnan who moved to Thailand are known as Chin Haw and they also own restaurants and stalls serving Chinese Islamic food.Restaurant in Bishkek, Kyrgyzstan, advertising Dungan cuisine.In Central Asia, Dungan people, descendants of Hui, operate restaurants serving Chinese Islamic cuisine, which is respectively referred to as ''Dungan cuisine'' there.", "They cater to Chinese businessmen.", "Chopsticks are used by Dungans.", "The cuisine of the Dungan resembles northwestern Chinese cuisine.Halal food is regulated and certified by local governments in China.", "Hui who migrated to Northeast China (Manchuria) after the Chuang Guandong opened many new inns and restaurants to cater to travelers.The Hui who migrated to Taiwan operate Qingzhen restaurants and stalls serving Chinese Islamic cuisine in Taipei and other big cities.The Thai Department of Export Promotion claims that \"China's halal food producers are small-scale entrepreneurs whose products have little value added and lack branding and technology to push their goods to international standards\" to encourage Thai private sector halal producers to market their products in China.A 1903-started franchise serving Muslim food is Dong Lai Shun in Hankou.400 meters have to be kept as a distance from each restaurant serving beef noodles to another of its type if they belong to Hui Muslims, since Hui have a pact between each other in Ningxia, Gansu and Shaanxi.Halal restaurants are checked up upon by clerics from mosques.Halal food manufacture has been sanctioned by the government of the Ningxia Autonomous Region." ], [ "Famous dishes", "Chinese halal restaurant in Taipei, TaiwanMelaka, Malaysia===Lamian==='''Lamian''' (, Dungan: Ламян) is a Chinese dish of hand-made noodles, usually served in a beef or mutton-flavored soup (湯麪, даңмян, tāngmiàn), but sometimes stir-fried (炒麪, Чаомян, chǎomiàn) and served with a tomato-based sauce.", "Literally, 拉, ла (lā) means to pull or stretch, while 麪, мян (miàn) means noodle.", "The hand-making process involves taking a lump of dough and repeatedly stretching it to produce a single very long noodle.Words that begin with L are not native to Turkic — läghmän is a loanword as stated by Uyghur linguist Abdlikim: It is of Chinese derivation and not originally Uyghur.The earliest description of making lamian noodles with the pulling technique is found in the ''Songshi Yangsheng Bu'' (宋氏養生部), a dietary manual written in 1504 by Song Xu (宋詡), an agriculturalist and gastronomer of the Ming dynasty.", "Lamian without beef was invented by Han Chinese, while the specific dish Lanzhou beef lamian was invented centuries later by Muslims, either Dongxiang or Hui.===Beef noodle soup==='''Beef noodle soup''' is a noodle soup dish composed of stewed beef, beef broth, vegetables and wheat noodles.", "It exists in various forms throughout East and Southeast Asia.", "It was created by either Hui or Dongxiang people in the late 18th-early 19th century of northwest China (Gansu, Qinghai, Ningxia) during the Qing dynasty.In the west, this food may be served in a small portion as a soup.", "In China, a large bowl of it is often taken as a whole meal with or without any side dish.===Chuanr==='''Chuanr''' (Chinese: 串儿, Dungan: Чўанр, Pinyin: chuànr (shortened from \"chuan er\"), \"''kebab''\"), originating in the Xinjiang (新疆) province of China and in recent years has been disseminated throughout the rest of that country, most notably in Beijing.", "It is a product of the Chinese Islamic cuisine of the Uyghur (维吾尔) people and other Chinese Muslims.", "Yang rou chuan or lamb kebabs, is particularly popular.===Suan cai==='''Suan cai''' is a traditional fermented vegetable dish, similar to Korean kimchi and German sauerkraut, used in a variety of ways.", "It consists of pickled Chinese cabbage.", "Suan cai is a unique form of pao cai due to the material used and the method of production.", "Although ''suan cai'' is not exclusive to Chinese Islamic cuisine, it is used in Chinese Islamic cuisine to top off noodle soups, especially beef noodle soup.===Nang===''Nang'' (Chinese: 馕, Dungan: Нәң) is a type of round unleavened bread, topped with sesame.", "It is similar to South and Central Asia naan." ], [ "Image gallery", "File:Beef noodle.JPG|Beef noodle servedFile:Peking Duck.jpg|Peking duck served at a halal restaurant in BeijingFile:5658-Linxia-City-niang-pi.jpg|''Niang pi'' (酿皮, Няң пы), a popular vegetarian noodle cold dish in Linxia" ], [ "See also", "* Chinese cuisine* Islam in China* Uyghur cuisine* Dali City* Gansu* Kunming* Lanzhou* Ningxia* Qinghai* Shaanxi* Xi'an* Yunnan" ], [ "References" ], [ "External links", "* article on a Chinese Islamic restaurant in the San Francisco Bay area, ''San Francisco Chronicle''.", "* chinaheritagequarterly.org* The Famous Dungan Noodles or Lyu Mian with Eight Seasoning Dishes!", "* More pictures of the Dungan Cuisine" ] ]
wikipedia
[ [ "Cantonese cuisine" ], [ "Introduction", "Map showing major regional cuisines of China'''Cantonese''' or '''Guangdong cuisine''', also known as '''Yue cuisine''' ( or ) is the cuisine of Guangdong province of China, particularly the provincial capital Guangzhou, and the surrounding regions in the Pearl River Delta including Hong Kong and Macau.", "Strictly speaking, Cantonese cuisine is the cuisine of Guangzhou or of Cantonese speakers, but it often includes the cooking styles of all the speakers of Yue Chinese languages in Guangdong.", "The Teochew cuisine and Hakka cuisine of Guangdong are considered their own styles.", "However, scholars may categorize Guangdong cuisine into three major groups based on the region's dialect: Cantonese, Hakka and Chaozhou cuisines.", "Neighboring Guangxi's cuisine is also considered separate despite eastern Guangxi being considered culturally Cantonese due to the presence of ethnic Zhuang influences in the rest of the province.", "Cantonese cuisine is one of the Eight Great Traditions of Chinese cuisine.", "Its prominence outside China is due to the large number of Cantonese emigrants.", "Chefs trained in Cantonese cuisine are highly sought after throughout China.", "Until the late 20th century, most Chinese restaurants in the West served largely Cantonese dishes." ], [ "Background", "Guangzhou (Canton) City, the provincial capital of Guangdong and the centre of Cantonese culture, has long been a trading hub and many imported foods and ingredients are used in Cantonese cuisine.", "Besides pork, beef and chicken, Cantonese cuisine incorporates almost all edible meats, including offal, chicken feet, duck's tongue, frog legs, snakes and snails.", "However, lamb and goat are less commonly used than in the cuisines of northern or western China.", "Many cooking methods are used, with steaming and stir-frying being the most favoured due to their convenience and rapidity.", "Other techniques include shallow frying, double steaming, braising and deep frying.Compared to other Chinese regional cuisines, the flavours of most traditional Cantonese dishes should be well-balanced and not greasy.", "Apart from that, spices should be used in modest amounts to avoid overwhelming the flavours of the primary ingredients, and these ingredients in turn should be at the peak of their freshness and quality.", "There is no widespread use of fresh herbs in Cantonese cooking, in contrast with their liberal use in other cuisines such as Sichuanese, Vietnamese, Lao, Thai and European.", "Garlic chives and coriander leaves are notable exceptions, although the former are often used as a vegetable and the latter are usually used as mere garnish in most dishes." ], [ "Foods", "=== Sauces and condiments ===In Cantonese cuisine, ingredients such as sugar, salt, soy sauce, rice wine, corn starch, vinegar, scallion and sesame oil suffice to enhance flavour, although garlic is heavily used in some dishes, especially those in which internal organs, such as entrails, may emit unpleasant odours.", "Ginger, chili peppers, five-spice powder, powdered black pepper, star anise and a few other spices are also used, but often sparingly.", "English Traditional Chinese Simplified Chinese Jyutping Pinyin Black bean sauce syun3 jung4 dau6 si6 zoeng3 suànróng dòuchǐjiàng Char siu sauce caa1 siu1 zoeng3 chāshāojiàng Chu hau paste cyu5 hau4 zoeng3 zhùhóujiàng Hoisin sauce hoi2 sin1 zoeng3 hǎixiānjiàng Master stock lou5 seoi2 lǔshuǐ Oyster sauce hou4 jau4 háoyóu Plum sauce syun1 mui4 zoeng3 sūméijiàng Red vinegar daai6 hung4 zit3 cou3 dàhóngzhècù Shrimp paste haam4 haa1 zoeng3 xiánxiājiàng Sweet and sour sauce tong4 cou3 zoeng3 tángcùjiàngFile:Macharsiew by daxiang stef.jpg|Char siu is often marinated with plum sauce and honey for sweet flavourFile:Steamed Oysters.jpg|Oysters steamed in two ways: with ginger and garlic, and in black bean sauce ===Dried and preserved ingredients===Although Cantonese cooks pay much attention to the freshness of their primary ingredients, Cantonese cuisine also uses a long list of preserved food items to add flavour to a dish.", "This may be influenced by Hakka cuisine, since the Hakkas were once a dominant group occupying imperial Hong Kong and other southern territories.Some items gain very intense flavours during the drying/preservation/oxidation process and some foods are preserved to increase their shelf life.", "Some chefs combine both dried and fresh varieties of the same items in a dish.", "Dried items are usually soaked in water to rehydrate before cooking.", "These ingredients are generally not served ''a la carte'', but rather with vegetables or other Cantonese dishes.", "Image English Traditional Chinese Simplified Chinese Jyutping Pinyin Notes120px Century egg pei4 daan2 pídàn Can be found served with roasted dishes, in congee with lean pork, and in a sweet pastry with lotus paste.", "120px Chinese sausage laap6 coeng2 làcháng Usually added to rice together with preserved-salted duck and pork.120pxDried cabbage coi3 gon1 càigān 120px Dried scallops gong1 jiu4 cyu5 jiāngyáozhù Usually added to clear soup.", "120px Dried shrimp haa1 gon1 xiāgān Usually de-shelled, sliced into half and added to vegetable dishes.120px Dried small shrimp haa1 mai5 xiāmǐ Usually mixed with stir-fried vegetables.120px Fermented tofu fu6 jyu5 fǔrǔ 120px Fermented black beans dau6 si6 dòuchǐ Usually added to pork and tofu dishes.120px Pickled Chinese cabbage mui4 coi3 méicài Usually cooked with pork or stir-fried with rice.120pxPickled diced radish coi3 pou2 càifǔ 120pxPreserved-salted duck laap6 aap2 làyā Usually eaten with rice in a family meal.120pxPreserved-salted pork laap6 juk6 làròu Usually eaten with rice in a family meal.120px Salted duck egg haam4 daan2 xiándàn May be eaten as it is or mixed with stir-fried vegetables and steam dishes or cooked with diced pork in congee.120px Salted fish haam4 jyu2 xiányú Usually paired with steamed pork or added to fried rice together with diced chicken.120px Suan cai haam4 syun1 coi3 xiánsuāncài 120pxTofu skin fu6 pei4 fǔpí Usually used as wrapping for ground pork dishes.", "It is fried in a similar manner as spring rolls.===Traditional dishes===A number of dishes have been part of Cantonese cuisine since the earliest territorial establishments of Guangdong.", "While many of these are on the menus of typical Cantonese restaurants, some simpler ones are more commonly found in Cantonese homes.", "Home-made Cantonese dishes are usually served with plain white rice.", "Name Image Traditional Chinese Simplified Chinese Jyutping Pinyin Cantonese style fried rice 100px gwong2 sik1 cau2 faan6 guǎng shì chǎofàn Choy sum in oyster sauce 100px hou4 jau4 coi3 sam1 háoyóu càixīn Congee with lean pork and century egg 100px pei4 daan2 sau3 juk6 zuk1 pídàn shòuròuzhōu Steamed egg 100px zing1 seoi2 daan2 zhēngshuǐdàn Steamed frog legs on lotus leaf | ho4 jip6 zing1 tin4 gai1 héyè zhēng tiánjī Steamed ground pork with salted duck egg 100px haam4 daan2 zing1 juk6 beng2 xiándàn zhēng ròubǐng Steamed spare ribs with fermented black beans and chilli pepper 100px si6 ziu1 paai4 gwat1 chǐjiāo páigǔ Stewed beef brisket 100px cyu5 hau4 ngau4 naam5 zhùhóu niú nǎn Stir-fried hairy gourd with dried shrimp and cellophane noodles | daai6 ji4 maa1 gaa3 neoi5 dàyímā jiànǚ Stir-fried water spinach with shredded chilli and fermented tofu 100px ziu1 si1 fu6 jyu5 tung1 coi3 jiāosī fǔrǔ tōngcài Sweet and sour pork 100px gu1 lou1 juk6 gūlūròu Shunde-style fish slices 100px seon6 dak1 jyu4 saang1 shùndé yú shēng===Deep fried dishes===There are a small number of deep-fried dishes in Cantonese cuisine, which can often be found as street food.", "They have been extensively documented in colonial Hong Kong records of the 19th and 20th centuries.", "A few are synonymous with Cantonese breakfast and lunch, even though these are also part of other cuisines.", "English Image Traditional Chinese Simplified Chinese Jyutping Pinyin Dace fish balls 100px leng4 jyu4 kau4 Chinese Donut 100px jau4 zaa3 gwai2 Zaa Leung 100px zaa3 loeng5 === Soups ===Old fire soup, or ''lou fo tong'' (), is a clear broth prepared by simmering meat and other ingredients over a low heat for several hours.", "Chinese herbs are often used as ingredients.", "There are basically two ways to make old fire soup – put ingredients and water in the pot and heat it directly on fire, which is called ''bou tong'' (); or put the ingredients in a small stew pot, and put it in a bigger pot filled with water, then heat the bigger pot on fire directly, which is called ''dun tong'' ().", "The latter way can keep the most original taste of the soup.Soup chain stores or delivery outlets in cities with significant Cantonese populations, such as Hong Kong, serve this dish due to the long preparation time required of slow-simmered soup.", "English Traditional Chinese Simplified Chinese Jyutping Pinyin Cantonese seafood soup hoi2 wong4 gang1 hǎihuáng gēng Night-blooming cereus soup baa3 wong4 faa1 bou1 tong1 bàwánghuā bāotāng Snow fungus soup ngan4 ji5 tong1 yín'ěr tāng Spare ribs soup with watercress and apricot kernels naam4 bak1 hang6 sai1 joeng4 coi3 zyu1 gwat1 tong1 nánběixìng xīyángcài zhūgǔ tāng Winter melon soup dung1 gwaa1 tong1 dōngguā tāng=== Seafood ===Seafood tanks in a Cantonese restaurantDue to Guangdong's location along the South China Sea coast, fresh seafood is prominent in Cantonese cuisine, and many Cantonese restaurants keep aquariums or seafood tanks on the premises.", "In Cantonese cuisine, as in cuisines from other parts of Asia, if seafood has a repugnant odour, strong spices and marinating juices are added; the freshest seafood is odourless and, in Cantonese culinary arts, is best cooked by steaming.", "For instance, in some recipes, only a small amount of soy sauce, ginger and spring onion is added to steamed fish.", "In Cantonese cuisine, the light seasoning is used only to bring out the natural sweetness of the seafood.", "As a rule of thumb, the spiciness of a dish is usually negatively correlated to the freshness of the ingredients.", "English Traditional Chinese Simplified Chinese Jyutping Pinyin Lobster with ginger and scallions goeng1 cung1 lung4 haa1 jiāngcōng lóngxiā Mantis shrimp laai6 niu6 haa1 làniàoxiā Steamed fish zing1 yu4 zhēngyú Steamed scallops with ginger and garlic syun3 jung4 zing1 sin3 bui3 suànróng zhēng shànbèi White boiled shrimp baak6 zoek3 haa1 báizhuóxiāFile:HK Hotpot foods Dec-2013 Ingredients 蟶子 Solenidae 蟹 Crabs 蝦 Prawn 雞肉腸仔 Sausage n 魚旦 Fishballs.jpg|Typical ingredients for Cantonese style hotpot are razor shell (), crab (), prawn (), chicken sausage () and dace fishball ()=== Noodle dishes ===Noodles are served either in soup broth or fried.", "These are available as home-cooked meals, on dim sum side menus, or as street food at dai pai dongs, where they can be served with a variety of toppings such as fish balls, beef balls, or fish slices.", "English Image Traditional Chinese Simplified Chinese Jyutping Pinyin Notes Beef brisket noodles 100px ngau4 laam5 min6 niú nǎn miàn May be served dry or in soup.", "Beef chow fun100px gon1 caau2 ngau4 ho2 gān chǎo niú hé Chow mein100px caau2 min6 chǎo miàn A generic term for various stir-fried noodle dishes.", "Hong Kong-style chow mein is made from pan-fried thin crispy noodles.", "Jook-sing noodles zuk1 sing1 min6 zhúshēngmiàn Bamboo log pressed noodles.", "Lo mein 100px lou1 min6 lāo miàn Rice noodle roll100px coeng2 fan2 chángfěn Also known as chee cheong fun.", "Rice noodles 100px ho4 fun2 héfěn Also known as hor-fun.", "Silver needle noodles100px ngan4 zam1 fun2 yín zhēn fěn Also known as rat noodles ().", "Yi mein100px ji1 min6 yī miàn Also known as e-fu noodles.", "Wonton noodles100px wan4 tan1 min6 yúntūn miàn Sometimes spelled as wanton noodles.===Siu mei===A roasted pig and char siu''Siu mei'' () is essentially the Chinese rotisserie style of cooking.", "Unlike most other Cantonese dishes, ''siu mei'' solely consists of meat, with no vegetables.", "English Image Traditional Chinese Simplified Chinese Jyutping Pinyin Char siu 100px caa1 siu1 chāshāo Roast duck 100px siu1 aap3 shāoyā Roast goose 100px siu1 ngo4 shāo'é Roast pig 100px siu1 yuk1 shāoròu Roast pigeon 100px siu1 jyu5 gap3 shāorǔgē===Lou mei==='''Lou mei''' () is the name given to dishes made from internal organs, entrails and other left-over parts of animals.", "It is widely available in southern Chinese regions.Image English Traditional Chinese Simplified Chinese Jyutping Pinyin120px Beef entrails ngau4 zaap6 niú zá120px Beef brisket ngau4 laam5 niú nǎn120px Chicken scraps gai1 zaap6 jī zá Duck gizzard aap3 san6 yā shèn Pig's tongue zyu1 lei6 zhū lì===Siu laap===Cantonese siu mei food stall in Hong KongAll Cantonese-style cooked meats, including siu mei, lou mei and preserved meat can be classified as '''siu laap''' ().", "''Siu laap'' also includes dishes such as: English Image Traditional Chinese Simplified Chinese Jyutping Pinyin Notes Chicken in soy sauce 100px si6 jau4 gai1 chǐ yóu jī Orange cuttlefish 100px lou5 seoi2 mak6 jyu4 lǔshuǐ mòyú Poached duck in master stock | lou5 seoi2 aap3 lǔ shuǐ yā White cut chicken 100px baak6 cit3 gai1 bái qiè jī Also known as white chopped chicken () in some places.A typical dish may consist of offal and half an order of multiple varieties of roasted meat.", "The majority of siu laap is white meat.", "English Image Traditional Chinese Simplified Chinese Jyutping Pinyin Rice with Chinese sausage and char siu 100px laap6 ceung4 caa1 siu1 faan6 làcháng chāshāo fàn Rice with roast goose and goose intestines siu1 ngo4 ngo4 coeng4 faan6 shāo é é cháng fàn Siu mei platter 100px siu1 mei6 ping6 poon4 shāowèi pīnpán Siu lap platter 100px siu1 laap6 ping6 pun4 shāolà pīnpán===Little pot rice===Little pot chicken rice with vegetable and Chinese sausageLittle pot rice () are dishes cooked and served in a flat-bottomed pot (as opposed to a round-bottomed wok).", "Usually this is a saucepan or braising pan (see clay pot cooking).", "Such dishes are cooked by covering and steaming, making the rice and ingredients very hot and soft.", "Usually the ingredients are layered on top of the rice with little or no mixing in between.", "Many standard combinations exist.", "English Traditional Chinese Simplified Chinese Jyutping Pinyin Rice with Chinese sausage and preserved meat laap6 coeng2 bou1 zai2 faan6 làwèi bāozǎifàn Rice with layered egg and beef wo1 daan2 ngaw4 juk6 faan6 wōdàn niúròu fàn Rice with minced beef patty juk6 beng2 bou1 zai2 faan6 ròubǐng bāozǎifàn Rice with spare ribs paai4 gwat1 bou1 zai2 faan6 páigǔ bāozǎifàn Rice with steamed chicken zing1 gai1 juk6 bou1 zai2 faan6 zhēng jīròu bāozǎifàn===Banquet/dinner dishes===A number of dishes are traditionally served in Cantonese restaurants only at dinner time.", "Dim sum restaurants stop serving bamboo-basket dishes after the yum cha period (equivalent to afternoon tea) and begin offering an entirely different menu in the evening.", "Some dishes are standard while others are regional.", "Some are customised for special purposes such as Chinese marriages or banquets.", "Salt and pepper dishes are one of the few spicy dishes.", "English Image Traditional Chinese Simplified Chinese Jyutping Pinyin Crispy fried chicken 100px zaa3 zi2 gai1 zhá zǐ jī Duck with taro can4 pei4 wu6 tau4 aap3 chén pí yùtóu yā Fried tofu with shrimp 100px haa1 joeng4 caau2 dau4 fu6 xiārén chǎo dòufǔ Roast pigeon 100px jyu5 gap3 rǔ gē Roast suckling pig 100px siu1 jyu5 zyu1 shāo rǔ zhū Seafood with bird's nest 100px hoi2 sin1 zoek3 caau4 hǎixiān quècháo Shrimp with salt and pepper 100px ziu1 jim4 haa1 jiāo yán xiā Sour spare ribs 100px saang1 cau2 paai4 gwat1 shēng chǎo páigǔ Spare ribs with salt and pepper 100px ziu1 jim4 paai4 gwat1 jiāo yán gǔ Squid with salt and pepper 100px ziu1 jim4 jau4 jyu2 jiāo yán yóuyú Yangzhou fried rice 100px Joeng4 zau1 cau2 faan6 Yángzhōu chǎofàn===Dessert===After the evening meal, most Cantonese restaurants offer ''tong sui'' (), a sweet soup.", "Many varieties of ''tong sui'' are also found in other Chinese cuisines.", "Some desserts are traditional, while others are recent innovations.", "The more expensive restaurants usually offer their specialty desserts.", "Sugar water is the general name of dessert in Guangdong province.", "It is cooked by adding water and sugar to some other cooking ingredients.", "English Image Traditional Chinese Simplified Chinese Jyutping Pinyin Black sesame soup 100px zi1 maa4 wu2 zhīmahú Coconut pudding 100px je4 zap1 gou1 yēzhīgāo Double skin milk 100px soeng1 pei4 naai5 shuāngpínǎi Mung bean soup 100px luk6 dau6 saa1 lǜdòushā Red bean soup 100px hong4 dau6 saa1 hóngdòushā Sago soup 100px sai1 mei5 lou6 xīmǐlù Shaved ice 100px paau4 bing1 bǎobīng Steamed egg custard dan6 daan2 dùndàn Steamed milk custard dan6 naai5 dùnnǎi Sweet Chinese pastry 100px gou1 dim2 gāodiǎn Sweet potato soup 100px faan1 syu4 tong4 seoi2 fānshǔ tángshuǐ Tofu flower pudding 100px dau6 fu6 faa1 dòufǔhuā Tortoise Jelly100px gwai1 ling4 gou1 guīlínggāo===Delicacies===Certain Cantonese delicacies consist of parts taken from rare or endangered animals, which raises controversy over animal rights and environmental issues.", "This is often due to alleged health benefits of certain animal products.", "For example, the continued spreading of the idea that shark cartilage can cure cancer has led to decreased shark populations even though scientific research has found no evidence to support the credibility of shark cartilage as a cancer cure.", "English Image Traditional Chinese Simplified Chinese Jyutping Pinyin Bird's nest soup 100px jin1 wo1 yànwō Braised abalone 100px mun6 baau1 jyu4 mèn bàoyú Jellyfish 100px hoi2 zit3 hǎizhé Sea cucumber 100px hoi2 saam1 hǎishēn Shark fin soup 100px jyu4 ci3 tong1 yúchì tāng" ], [ "See also", "* Cantonese culture* Chinese food therapy* Dim sum* Hong Kong cuisine* List of Chinese dishes* Macanese cuisine* Restaurant industry in Guangzhou" ], [ "References" ], [ "Further reading", "*''Eight Immortal Flavors: Secrets of Cantonese Cookery from San Francisco's Chinatown'', Johnny Kan and Charles L. Leong.", "Berkeley, California: Howell-North Books, 1963" ] ]
wikipedia
[ [ "Teochew cuisine" ], [ "Introduction", "'''Teochew cuisine''', also known as '''Chiuchow cuisine''', '''Chaozhou cuisine''' or '''Teo-swa cuisine''', originated from the Chaoshan region in the eastern part of China's Guangdong Province, which includes the cities of Chaozhou, Shantou and Jieyang.", "Teochew cuisine bears more similarities to that of Fujian cuisine, particularly Southern Min cuisine, due to the similarity of Teochew 's and Fujian's culture, language, and their geographic proximity to each other.", "However, Teochew cuisine is also influenced by Cantonese cuisine in its style and technique." ], [ "Background", "Teochew cuisine is well known for its seafood and vegetarian dishes.", "Its use of flavouring is much less heavy-handed than most other Chinese cuisines and depends much on the freshness and quality of the ingredients for taste and flavour.", "As a delicate cuisine, oil is not often used in large quantities and there is a relatively heavy emphasis on poaching, steaming and braising, as well as the common Chinese method of stir-frying.", "Teochew cuisine is also known for serving congee (; or ''mue''), in addition to steamed rice or noodles with meals.", "The Teochew '''' is rather different from the Cantonese counterpart, being very watery with the rice sitting loosely at the bottom of the bowl, while the Cantonese dish is more a thin gruel.Authentic Teochew restaurants serve very strong oolong tea called Tieguanyin in very tiny cups before and after the meal.", "Presented as ''gongfu'' tea, the tea has a thickly bittersweet taste, colloquially known as ''gam gam'' ().A condiment that is popular in Fujian and Taiwanese cuisine and commonly associated with cuisine of certain Teochew groups is shacha sauce ().", "It is made from soybean oil, garlic, shallots, chilies, brill fish and dried shrimp.", "The paste has a savoury and slightly spicy taste.", "As an ingredient, it has multiple uses: as a base for soups, as a rub for barbecued meats, as a seasoning for stir-fried dishes, or as a component for dipping sauces.In addition to soy sauce (widely used in all Chinese cuisines), the Teochew diaspora in Southeast Asia use fish sauce in their cooking.", "It is used as a flavouring agent in soups and sometimes as a dipping sauce, as in Vietnamese spring rolls.Teochew chefs often use a special stock called superior broth ().", "This stock remains on the stove and is continuously replenished.", "Portrayed in popular media, some Hong Kong chefs allegedly use the same superior broth that is preserved for decades.", "This stock can as well be seen on Chaozhou TV's cooking programmes.There is a notable feast in Teochew cuisine called '''' ().", "A myriad of dishes are often served, which include shark fin soup, bird's nest soup, lobster, steamed fish, roasted suckling pig and braised goose.Teochew chefs take pride in their skills of vegetable carving, and carved vegetables are used as garnishes on cold dishes and on the banquet table.Teochew cuisine is also known for a late night meal known as ''meh siao'' () or ''daa laang'' () among the Cantonese.", "Teochew people enjoy eating out close to midnight in restaurants or at roadside food stalls.", "Some dai pai dong-like eateries stay open till dawn.Unlike the typical menu selections of many other Chinese cuisines, Teochew restaurant menus often have a dessert section.Many people of Teochew origin, also known as Teochiu or Teochew people, have settled in Hong Kong and places in Southeast Asia like Malaysia, Singapore, Cambodia and Thailand.", "Influences they bring can be noted in Singaporean cuisine and that of other settlements.", "A large number of Teochew people have also settled in Taiwan, evident in Taiwanese cuisine.", "Other notable Teochew diaspora communities are in Vietnam, Cambodia and France.", "A popular noodle soup in both Vietnam and Cambodia, known as hu tieu, originated from the Teochew .", "There is also a large diaspora of Teochew people (most were from Southeast Asia) in the United States - particularly in California.", "There is a Teochew Chinese Association in Paris called L'Amicale des Teochews en France." ], [ "Notable dishes", " English Traditional Chinese Simplified Chinese Pinyin Chaoshan transliteration Description Bak chor mee bak chor mee Boiled noodles, dried and mixed with variety sauce such as soy sauce, chilli sauce and lard topped with vegetables, sliced onion, minced pork, mushrooms and fish balls or fishcakes.", "Bak kut teh bak kut A hearty soup that, at its simplest, consists of meaty pork ribs in a complex broth of herbs and spices (including star anise, cinnamon, cloves, danggui, fennel seeds and garlic), boiled together with pork bones for hours.", "Dark and light soy sauce may also be added to the soup during the cooking stages.", "Some Teochew families like to add extra Chinese herbs such as yuzhu (rhizome of Solomon's seal) and juzhi (buckthorn fruit) for a sweeter, slightly stronger flavoured soup.", "The dish is usually eaten with rice or noodles (sometimes as a noodle soup), and often served with youtiao.", "Garnish includes chopped coriander or green onions and a sprinkling of fried shallots.", "A variation of bak kut uses chicken instead of pork, which then becomes chik kut teh.", "Bak kut is particularly popular in Southeast Asian countries such as Singapore and Malaysia.", "Braised varieties lo bah Teochew cuisine is noted for its variety of braised dishes, which includes geese, duck, pork, bean curd and offal.", "Chai tau kueh chai tau kueh A savoury fried cake, made of white radish and rice flour.", "It is commonly stir-fried with soy sauce, eggs, garlic, spring onion and occasionally dried shrimp.", "Sichuan pepper chicken cuêng ziê goi A traditionally deep-fried chicken dish, usually accompanied with leafy green from ''lysimachia clethroides'', known as pearl vegetable ().", "However, ''lysimachia clethroides'''s leaves are unavailable to use in culinary outside of China, but basil, spinach, or other leafy green vegetables can be substitutes to them in preparation of the dish.", "Chwee kueh chwee kueh Cup-shaped steamed rice cakes topped with chopped preserved/salted radish.", "Crystal balls zhui jia bao A steamed dessert with a variety of fillings such as yellow milk (; ''ni ng''), yam paste (; ''or ni'') or bean paste made from mung beans or azuki beans.", "They are similar to mochi.", "Fish balls / fishcakes / fish dumplings her ee / her kueh / her kiaw This fish paste made into balls, cakes and dumplings can be cooked in many ways but are often served in Teochew-style noodle and soups.", "Flavored-potted goose lou zui gho A well-known braised goose dish, often accompanised by tofu.", "Fried bean curd za dao hu A simple deep fried tofu dish, and was later adopted by Guangzhou's residents.", "First, deep-fry slices of fresh firm tofu until they are golden, and then serve with salted water dip (ingredients are boiling water, salt, and chopped Chinese chives).", "In modern times, some Teochew people now use the air fryer to prepare them for convenience and reduction of the amount of fat and calories in the food.", "Fried beef balls za ghu bak ee A simple deep-fired beef ball dish serves with dipping sauce such as shacha sauce or salted water dip (ingredients are boiling water, salt, and chopped Chinese chives).", "In modern times, some Teochew people now use the air fryer to prepare them for convenience and reduction of the amount of fat and calories in the food.", "Fish ball noodle soup her ee mee Any of several kinds of egg and rice noodles may be served either in a light fish-flavoured broth or dry, along with fishballs, fishcakes, beansprouts and lettuce.", "Fun guo hung gue A type of steamed dumplings.", "This is usually filled with dried radish, garlic chives, ground pork, dried shrimp, shiitake mushrooms and peanuts.", "The dumpling wrapper is made from a mixture of flour or plant starches mixed together with water.", "In Cantonese, these are called ''chiu chow fun guo'' (), in which the Chinese character is replaced by .", "Head mustard with mushrooms gao gou dua gai cai A dish of ''brassica juncea'' (Chinese mustard) and shiitake (Chinese black mushrooms) in a soup.", "Originally a vegetarian soup, it often added with diced pork belly and other ingredients.", "Kway chap kueh chap A dish of flat, broad rice sheets in a soup made from dark soy sauce served with pig offal, braised duck meat, various kinds of bean curd, preserved salted vegetables and braised hard-boiled eggs.", "Mee pok mee pok A popular noodle dish served with minced pork, braised mushrooms, fishballs, dumplings, sauce and other garnish.", "Oolong tea Ou-leeng Tieguanyin is one of the most popular Teochew teas.", "However, the Teochew people prefer their own brand of Oolong tea, which is the ''hong wang dan cong teh'' ().", "Oyster omelette or lua A dish of omelette cooked with fresh raw oysters, tapioca starch and eggs.", "Teochew-style oyster omelette is usually deep fried and very crisp.", "Dip condiments are fish sauce and pepper or chili sauce.", "Pan-fried marinated fish pu iem he A pan-fried dish of marinated fish, typically using a larimichthys crocea as the main ingredient but can use other alternatives such as a white croaker, Japanese sea bass or other types of bass, or tilefish.", "Patriotic soup (Protect the Country Dish) hu gog chai Developed during the Mongol conquest of the Song dynasty and named by Song's last emperor Zhao Bing.", "A simple soup boiled with stir-fried leaf vegetable (commonly sweet potato leaves since the Ming dynasty but also can use amaranth, spinach, ipomoea aquatica or other leafy greens as alternatives) and edible mushrooms (preferably straw mushrooms) and broth (vegetable, chicken, or beef).", "Pig's organ soup ter zap terng Popiah po piah A fresh (non-fried) spring roll usually eaten during the Qingming Festival.", "The skin is a soft, thin paper-like crepe made from wheat flour.", "The filling is mainly finely grated and steamed or stir-fried turnip, yam bean (jicama), which has been cooked with a combination of other ingredients such as bean sprouts, French beans, and lettuce leaves, depending on the individual vendor, along with grated carrots, slices of Chinese sausage, thinly sliced fried tofu, chopped peanuts or peanut powder, fried shallots and shredded omelette.", "Other common variations of popiah include pork (lightly seasoned and stir-fried), shrimp or crab meat.", "It is eaten in accompaniment with a sweet sauce (often a bean sauce, a blended soy sauce or hoisin sauce or a shrimp paste sauce).", "Pork jelly ter ka dang Braised pig's leg made into jelly form, sliced and served cold.", "Prawns sautéed with olive vegetables lam cai ju he A dish of deep-fried prawnsRed peach cake紅桃粿红桃粿ng tao guooung toh kwayPink hue rice flour skin wrapped with flavorful glutinous rice.", "Pressed on a nicely designed peach shaped wooden mould, and then steam the dumpling to perfection.", "You can eat it freshly steamed, or pan-fried.", "Salted vegetable duck soup kiam cai ak terng A soup boiled with duck, preserved salted vegetable, tomatoes and preserved sour plum.", "Spring rolls with prawn or minced meat fillings heh gerng / sio gerng / ngo hiang Mixed pork and prawn paste (sometimes fish), seasoned with five-spice powder, wrapped and rolled in a bean curd skin and deep-fried or pan-fried.", "It is sometimes referred to as Teochew-style spring roll in restaurant menus.", "Steamed chives dumplings gu chai gue They are sometimes sautéed to give them a crispy texture.", "Steamed goose chue gho Taro paste orh ni / orh nee A traditional Teochew dessert made primarily from taro.", "The taro is steamed and then mashed into a thick paste, which forms the base of the dessert.", "Pumpkin is also added for sweetness and to create a smoother consistency.", "Lard or fried onion oil is then added for fragrance.", "The dessert is traditionally sweetened with water chestnut syrup, and served with ginkgo nuts.", "Modern versions of the dessert include the addition of coconut cream and sweet corn.", "The dessert is commonly served at traditional Teochew wedding banquet dinners as the last course, marking the end of the banquet.", "Teochew chicken Teochew koi A dish of sliced chicken Teochew cold crab Teochew ngang hoi The whole crab is first steamed then served chilled.", "The species of crab most commonly used is ''Charybdis cruciata''.", "Teochew hot pot / Teochew steamboat Teochew zuang lou A dish where fresh, thinly sliced ingredients are placed into a simmering flavourful broth to cook and then dipped into various mixed sauces, usually with Shacha and soy sauce as its main components.", "Ingredients often include leafy vegetables, yam, tofu, pomfret and other seafood, beef balls, fish balls, pork balls, mushrooms and Chinese noodles, among others.", "Teochew hot pot, like other Chinese hot pots, is served in a large communal metal pot at the center of the dining table.", "Teochew rice noodle soup Teochew kuay teow A quintessential Teochew-style noodle soup that is also particularly popular in Vietnam and Cambodia (known respectively as ''hu tieu'' and ''kuy teav''), through the influx of Teochew immigrants.", "It is a dish of yellow egg noodles and thin rice noodles served in a delicate, fragrant soup with meatballs, other various meats, seafood (such as shrimp), fried fishcake slices, quail eggs, blanched Chinese cabbage and sometimes offal.", "The soup base is typically made of pork or chicken bones and dried squid.", "Just before serving, the noodle soup is garnished with fried minced garlic, fried shallots, thinly sliced scallions and fresh cilantro (coriander) sprigs.", "For those who enjoy their noodle soup with added depth, the solid ingredients may be dipped into Shacha sauce or Teochew chilli oil.", "Teochew-style congee Teochew mue A rice soup that has a more watery texture as compared to the Cantonese congee.", "It is commonly served with various salty accompaniments such as salted vegetables (''kiam chai''), preserved radish (''chai por''), black olive(''烏橄欖''), olive grits (''橄欖糝''), boiled salted duck eggs, fried salted fish and fried peanuts.", "Teochew-style steamed pomfret Teochew chue chioh her Silver pomfret steamed with preserved salted vegetables, lard and sour plums.", "Yusheng her sae A raw fish salad whose typical ingredients include fresh salmon, white radish, carrot, red pepper (capsicum), ginger, kaffir lime leaves, Chinese parsley, chopped peanuts, toasted sesame seeds, Chinese shrimp crackers or fried dried shrimp, and five-spice powder, with the dressing primarily made from plum sauce.", "It is customarily served as an appetiser to bring good luck for the new year and is usually eaten on the seventh day of the Lunar New Year." ], [ "Gallery", "File:HK Wan Chai 春園街 Spring Garden Lane night Chiu Chow food shop window.jpg|\"Flavor potted\" goose ()File:Teochew Sweet Yam Paste - After Stirring.jpg|Taro paste ()File:Shui jing bao zz.JPG|Crystal balls ()File:Teochew pomfret.jpg|Steamed fish ()File:Oyster omelette.jpg|Oyster omelette ()File:Khanom kuichai.jpg|Fried chive dumplings ()File:Song dynasty's 'patriotic soup' (prepared in Clovis California) 宋朝的“護國菜”（在加利福尼亞克洛維斯市製備）。.jpg|Patriotic Soup (Protect the Country Dish ())File:Fried Tofu (炸豆腐).jpg|A dish of fried tofu () with dipping sauce.File:Teochew rice noodle soup (潮州粿條).jpg|Teochew rice noodle soup ().File:Sautéed Prawns with Olive Vegetables (欖菜焗蝦).jpg|Sautéed Prawns with olive vegetables () .File:Teochew Hotpot (prepared in Clovis California) 潮州火鍋（在加利福尼亞克洛維斯市製備）.jpg|Teochew hotpot ()File:Sichuan pepper chicken - air-fried version (川椒雞 - 氣炸版).jpg|Sichuan pepper chicken ()" ], [ "See also", "*List of Chinese dishes*Teochew porridge*Teochew people" ], [ "References" ], [ "External links", "* Yeo's Teochew Popiah Recipe* Jenius' Teochew peach shaped kueh Recipe" ] ]
wikipedia
[ [ "Co-NP" ], [ "Introduction", "In computational complexity theory, '''co-NP''' is a complexity class.", "A decision problem X is a member of co-NP if and only if its complement is in the complexity class NP.", "The class can be defined as follows: a decision problem is in co-NP if and only if for every ''no''-instance we have a polynomial-length \"certificate\" and there is a polynomial-time algorithm that can be used to verify any purported certificate.That is, '''co-NP''' is the set of decision problems where there exists a polynomial and a polynomial-time bounded Turing machine ''M'' such that for every instance ''x'', ''x'' is a ''no''-instance if and only if: for some possible certificate ''c'' of length bounded by , the Turing machine ''M'' accepts the pair ." ], [ "Complementary Problems", "While an NP problem asks whether a given instance is a ''yes''-instance, its ''complement'' asks whether an instance is a ''no''-instance, which means the complement is in co-NP.", "Any ''yes''-instance for the original NP problem becomes a ''no''-instance for its complement, and vice versa.===Unsatisfiability===An example of an NP-complete problem is the Boolean satisfiability problem: given a Boolean formula, is it ''satisfiable'' (is there a possible input for which the formula outputs true)?", "The complementary problem asks: \"given a Boolean formula, is it ''unsatisfiable'' (do all possible inputs to the formula output false)?\".", "Since this is the ''complement'' of the satisfiability problem, a certificate for a ''no''-instance is the same as for a ''yes''-instance from the original NP problem: a set of Boolean variable assignments which make the formula true.", "On the other hand, a certificate of a ''yes''-instance for the complementary problem would be equally as complex as the ''no''-instance of the original NP satisfiability problem." ], [ "Dual Problems" ], [ "co-NP-completeness", "A problem ''L'' is co-NP-complete if and only if ''L'' is in co-NP and for any problem in co-NP, there exists a polynomial-time reduction from that problem to ''L''.=== Tautology Reduction ===Determining if a formula in propositional logic is a tautology is co-NP-complete: that is, if the formula evaluates to true under every possible assignment to its variables." ], [ "Relationship to other classes", "P, NP, co-NP, BPP, P/poly, PH, and PSPACEP, the class of polynomial time solvable problems, is a subset of both NP and co-NP.", "P is thought to be a strict subset in both cases (and demonstrably cannot be strict in one case and not strict in the other).NP and co-NP are also thought to be unequal.", "If so, then no NP-complete problem can be in co-NP and no co-NP-complete problem can be in NP.", "This can be shown as follows.", "Suppose for the sake of contradiction there exists an NP-complete problem that is in co-NP.", "Since all problems in NP can be reduced to , it follows that for every problem in NP, we can construct a non-deterministic Turing machine that decides its complement in polynomial time; i.e., .", "From this, it follows that the set of complements of the problems in NP is a subset of the set of complements of the problems in co-NP; i.e., .", "Thus .", "The proof that no co-NP-complete problem can be in NP if is symmetrical.co-NP is a subset of PH, which itself is a subset of PSPACE.===Integer Factorization===An example of a problem that is known to belong to both NP and co-NP (but not known to be in P) is integer factorization: given positive integers ''m'' and ''n'', determine if ''m'' has a factor less than ''n'' and greater than one.", "Membership in NP is clear; if ''m'' does have such a factor, then the factor itself is a certificate.", "Membership in co-NP is also straightforward: one can just list the prime factors of ''m'', all greater or equal to ''n'', which the verifier can confirm to be valid by multiplication and the AKS primality test.", "It is presently not known whether there is a polynomial-time algorithm for factorization, equivalently that integer factorization is in P, and hence this example is interesting as one of the most natural problems known to be in NP and co-NP but not known to be in P." ], [ "References" ], [ "External links", "*" ] ]
wikipedia
[ [ "Chuck Yeager" ], [ "Introduction", "Brigadier General '''Charles Elwood Yeager''' ( , February 13, 1923December 7, 2020) was a United States Air Force officer, flying ace, and record-setting test pilot who in October 1947 became the first pilot in history confirmed to have exceeded the speed of sound in level flight.Yeager was raised in Hamlin, West Virginia.", "His career began in World War II as a private in the United States Army, assigned to the Army Air Forces in 1941.After serving as an aircraft mechanic, in September 1942, he entered enlisted pilot training and upon graduation was promoted to the rank of flight officer (the World War II Army Air Force version of the Army's warrant officer), later achieving most of his aerial victories as a P-51 Mustang fighter pilot on the Western Front, where he was credited with shooting down 11.5 enemy aircraft (the half credit is from a second pilot assisting him in a single shootdown).", "On October 12, 1944, he attained \"ace in a day\" status, shooting down five enemy aircraft in one mission.After the war, Yeager became a test pilot and flew many types of aircraft, including experimental rocket-powered aircraft for the National Advisory Committee for Aeronautics (NACA).", "Through the NACA program, he became the first human to officially break the sound barrier on October 14, 1947, when he flew the experimental Bell X-1 at Mach 1 at an altitude of , for which he won both the Collier and Mackay trophies in 1948.He then went on to break several other speed and altitude records in the following years.", "In 1962, he became the first commandant of the USAF Aerospace Research Pilot School, which trained and produced astronauts for NASA and the Air Force.Yeager later commanded fighter squadrons and wings in Germany, as well as in Southeast Asia during the Vietnam War.", "In recognition of his achievements and the outstanding performance ratings of those units, he was promoted to brigadier general in 1969 and inducted into the National Aviation Hall of Fame in 1973, retiring on March 1, 1975.His three-war active-duty flying career spanned more than 30 years and took him to many parts of the world, including the Korean War zone and the Soviet Union during the height of the Cold War.Yeager is referred to by many as one of the greatest pilots of all time, and was ranked fifth on ''Flying'' list of the 51 Heroes of Aviation in 2013.Throughout his life, he flew more than 360 different types of aircraft over a 70-year period, and continued to fly for two decades after retirement as a consultant pilot for the United States Air Force." ], [ "Early life and education", "Yeager was born February 13, 1923, in Myra, West Virginia, to farming parents Albert Hal Yeager (1896–1963) and Susie Mae Yeager (; 1898–1987).", "When he was five years old, his family moved to Hamlin, West Virginia.", "Yeager had two brothers, Roy and Hal Jr., and two sisters, Doris Ann (accidentally killed at age two by six-year-old Roy playing with a firearm) and Pansy Lee.He attended Hamlin High School, where he played basketball and football, receiving his best grades in geometry and typing.", "He graduated from high school in June 1941.His first experience with the military was as a teen at the Citizens Military Training Camp at Fort Benjamin Harrison, Indianapolis, Indiana, during the summers of 1939 and 1940.On February 26, 1945, Yeager married Glennis Dickhouse, and the couple had four children.", "Glennis Yeager died in 1990, predeceasing her husband by 30 years.His cousin, Steve Yeager, was a professional baseball catcher." ], [ "Career", "=== World War II ===Yeager enlisted as a private in the U.S. Army Air Forces (USAAF) on September 12, 1941, and became an aircraft mechanic at George Air Force Base, Victorville, California.", "At enlistment, Yeager was not eligible for flight training because of his age and educational background, but the entry of the U.S. into World War II less than three months later prompted the USAAF to alter its recruiting standards.", "Yeager had unusually sharp vision (a visual acuity rated 20/10), which once enabled him to shoot a deer at .At the time of his flight training acceptance, he was a crew chief on an AT-11.He received his pilot wings and a promotion to flight officer at Luke Field, Arizona, where he graduated from Class 43C on March 10, 1943.Assigned to the 357th Fighter Group at Tonopah, Nevada, he initially trained as a fighter pilot, flying Bell P-39 Airacobras (being grounded for seven days for clipping a farmer's tree during a training flight), and shipped overseas with the group on November 23, 1943.captain, c. 1944Stationed in the United Kingdom at RAF Leiston, Yeager flew P-51 Mustangs in combat with the 363d Fighter Squadron.", "He named his aircraft ''Glamorous Glen'' after his girlfriend, Glennis Faye Dickhouse, who became his wife in February 1945.Yeager had gained one victory before he was shot down over France in his first aircraft (P-51B-5-NA s/n 43-6763) on March 5, 1944, on his eighth mission.", "He escaped to Spain on March 30, 1944, with the help of the ''Maquis'' (French Resistance) and returned to England on May 15, 1944.During his stay with the ''Maquis'', Yeager assisted the guerrillas in duties that did not involve direct combat; he helped construct bombs for the group, a skill that he had learned from his father.", "He was awarded the Bronze Star for helping a navigator, Omar M. \"Pat\" Patterson, Jr., to cross the Pyrenees.Despite a regulation prohibiting \"evaders\" (escaped pilots) from flying over enemy territory again, the purpose of which was to prevent resistance groups from being compromised by giving the enemy a second chance to possibly capture him, Yeager was reinstated to flying combat.", "He had joined another evader, fellow P-51 pilot 1st Lt Fred Glover, in speaking directly to the Supreme Allied Commander, General Dwight D. Eisenhower, on June 12, 1944.", "\"I raised so much hell that General Eisenhower finally let me go back to my squadron\" Yeager said.", "\"He cleared me for combat after D Day, because all the free Frenchmen – Maquis and people like that – had surfaced\".", "Eisenhower, after gaining permission from the War Department to decide the requests, concurred with Yeager and Glover.", "In the meantime, Yeager shot down his second enemy aircraft, a German Junkers Ju 88 bomber, over the English Channel.P-51D-20NA, ''Glamorous Glen III'', is the aircraft in which Yeager achieved most of his aerial victories.Yeager demonstrated outstanding flying skills and combat leadership.", "On October 12, 1944, he became the first pilot in his group to make \"ace in a day,\" downing five enemy aircraft in a single mission.", "Two of these victories were scored without firing a single shot: when he flew into firing position against a Messerschmitt Bf 109, the pilot of the aircraft panicked, breaking to port and colliding with his wingman.", "Yeager said both pilots bailed out.", "He finished the war with 11.5 official victories, including one of the first air-to-air victories over a jet fighter, a German Messerschmitt Me 262 that he shot down as it was on final approach for landing.In his 1986 memoirs, Yeager recalled with disgust that \"atrocities were committed by both sides\", and said he went on a mission with orders from the Eighth Air Force to \"strafe anything that moved\".", "During the mission briefing, he whispered to Major Donald H. Bochkay, \"If we are going to do things like this, we sure as hell better make sure we are on the winning side\".", "Yeager said, \"I'm certainly not proud of that particular strafing mission against civilians.", "But it is there, on the record and in my memory\".", "He also expressed bitterness at his treatment in England during World War II, prompting descriptions of the British as \"arrogant\" and \"nasty\" on Twitter.Yeager was commissioned a second lieutenant while at Leiston, and was promoted to captain before the end of his tour.", "He flew his 61st and final mission on January 15, 1945, and returned to the United States in early February 1945.As an evader, he received his choice of assignments and, because his new wife was pregnant, chose Wright Field to be near his home in West Virginia.", "His high number of flight hours and maintenance experience qualified him to become a functional test pilot of repaired aircraft, which brought him under the command of Colonel Albert Boyd, head of the Aeronautical Systems Flight Test Division.=== Post-World War II ======= Test pilot – breaking the sound barrier ====Yeager broke the sound barrier on October 14, 1947, in the X-1.Yeager remained in the U.S. Army Air Forces after the war, becoming a test pilot at Muroc Army Air Field (now Edwards Air Force Base), following graduation from Air Materiel Command Flight Performance School (Class 46C).", "After Bell Aircraft test pilot Chalmers \"Slick\" Goodlin demanded to break the sound \"barrier\", the USAAF selected the 24-year-old Yeager to fly the rocket-powered Bell XS-1 in a NACA program to research high-speed flight.", "Under the National Security Act of 1947, the USAAF became the United States Air Force (USAF) on September 18.Yeager in front of the Bell X-1, which, as with all of the aircraft assigned to him, he named ''Glamorous Glennis'' (or some variation thereof) after his wife.Yeager in the Bell X-1 cockpitSuch was the difficulty of this task that the answer to many of the inherent challenges was along the lines of \"Yeager better have paid-up insurance\".", "Two nights before the scheduled date for the flight, Yeager broke two ribs when he fell from a horse.", "He was worried that the injury would remove him from the mission and reported that he went to a civilian doctor in nearby Rosamond, who taped his ribs.", "Besides his wife who was riding with him, Yeager told only his friend and fellow project pilot Jack Ridley about the accident.", "On the day of the flight, Yeager was in such pain that he could not seal the X-1's hatch by himself.", "Ridley rigged up a device, using the end of a broom handle as an extra lever, to allow Yeager to seal the hatch.Yeager broke the sound barrier on October 14, 1947, in level flight while piloting the X-1 ''Glamorous Glennis'' at Mach 1.05 at an altitude of over the Rogers Dry Lake of the Mojave Desert in California.", "The success of the mission was not announced to the public for nearly eight months, until June 10, 1948.Yeager was awarded the Mackay Trophy and the Collier Trophy in 1948 for his mach-transcending flight, and the Harmon International Trophy in 1954.The X-1 he flew that day was later put on permanent display at the Smithsonian Institution's National Air and Space Museum.", "During 1952, he attended the Air Command and Staff College.Yeager in 1950Yeager went on to break many other speed and altitude records.", "He was also one of the first American pilots to fly a Mikoyan-Gurevich MiG-15, after its pilot, No Kum-sok, defected to South Korea.", "Returning to Muroc, during the latter half of 1953, Yeager was involved with the USAF team that was working on the X-1A, an aircraft designed to surpass Mach 2 in level flight.", "That year, he flew a chase aircraft for the civilian pilot Jackie Cochran as she became the first woman to fly faster than sound.On November 20, 1953, the U.S. Navy program involving the D-558-II Skyrocket and its pilot, Scott Crossfield, became the first team to reach twice the speed of sound.", "After they were bested, Ridley and Yeager decided to beat rival Crossfield's speed record in a series of test flights that they dubbed \"Operation NACA Weep\".", "Not only did they beat Crossfield by setting a new record at Mach 2.44 on December 12, 1953, but they did it in time to spoil a celebration planned for the 50th anniversary of flight in which Crossfield was to be called \"the fastest man alive\".The new record flight, however, did not entirely go to plan, since shortly after reaching Mach 2.44, Yeager lost control of the X-1A at about due to inertia coupling, a phenomenon largely unknown at the time.", "With the aircraft simultaneously rolling, pitching, and yawing out of control, Yeager dropped in less than a minute before regaining control at around .", "He then managed to land without further incident.", "For this feat, Yeager was awarded the Distinguished Service Medal (DSM) in 1954.==== Military command ====Yeager, as Commandant of the USAF Aerospace Research Pilot School with a model of the North American X-15, 1959Yeager was foremost a fighter pilot and held several squadron and wing commands.", "From 1954 to 1957, he commanded the F-86H Sabre-equipped 417th Fighter-Bomber Squadron (50th Fighter-Bomber Wing) at Hahn AB, West Germany, and Toul-Rosieres Air Base, France; and from 1957 to 1960 the F-100D Super Sabre-equipped 1st Fighter Day Squadron at George Air Force Base, California, and Morón Air Base, Spain.Now a full colonel in 1962, after completion of a year's studies and final thesis on STOL aircraft at the Air War College, Yeager became the first commandant of the USAF Aerospace Research Pilot School, which produced astronauts for NASA and the USAF, after its redesignation from the USAF Flight Test Pilot School.", "(Yeager himself had only a high school education, so he was not eligible to become an astronaut like those he trained.)", "In April 1962, Yeager made his only flight with Neil Armstrong.", "Their job, flying a T-33, was to evaluate Smith Ranch Dry Lake in Nevada for use as an emergency landing site for the North American X-15.In his autobiography, Yeager wrote that he knew the lake bed was unsuitable for landings after recent rains, but Armstrong insisted on flying out anyway.", "As Armstrong suggested that they do a touch-and-go, Yeager advised against it, telling him \"You may touch, but you ain't gonna go!\"", "When Armstrong did touch down, the wheels became stuck in the mud, bringing the plane to a sudden stop and provoking Yeager to fits of laughter.", "They had to wait for rescue.Yeager's participation in the test pilot training program for NASA included controversial behavior.", "Yeager reportedly did not believe that Ed Dwight, the first African American pilot admitted into the program, should be a part of it.", "In the 2019 documentary series ''Chasing the Moon'', the filmmakers made the claim that Yeager instructed staff and participants at the school that \"Washington is trying to cram the nigger down our throats.", "President Kennedy is using this to make 'racial equality,' so do not speak to him, do not socialize with him, do not drink with him, do not invite him over to your house, and in six months he'll be gone.\"", "In his autobiography, Dwight details how Yeager's leadership led to discriminatory treatment throughout his training at Edwards Air Force Base.Between December 1963 and January 1964, Yeager completed five flights in the NASA M2-F1 lifting body.", "An accident during a December 1963 test flight in one of the school's NF-104s resulted in serious injuries.", "After climbing to a near-record altitude, the plane's controls became ineffective, and it entered a flat spin.", "After several turns, and an altitude loss of approximately 95,000 feet, Yeager ejected from the plane.", "During the ejection, the seat straps released normally, but the seat base slammed into Yeager, with the still-hot rocket motor breaking his helmet's plastic faceplate and causing his emergency oxygen supply to catch fire.", "The resulting burns to his face required extensive and agonizing medical care.", "This was Yeager's last attempt at setting test-flying records.In 1966, Yeager took command of the 405th Tactical Fighter Wing at Clark Air Base, the Philippines, whose squadrons were deployed on rotational temporary duty (TDY) in South Vietnam and elsewhere in Southeast Asia.", "There he flew 127 missions.", "In February 1968, Yeager was assigned command of the 4th Tactical Fighter Wing at Seymour Johnson Air Force Base, North Carolina, and led the McDonnell Douglas F-4 Phantom II wing in South Korea during the ''Pueblo'' crisis.Yeager was promoted to brigadier general and was assigned in July 1969 as the vice-commander of the Seventeenth Air Force.From 1971 to 1973, at the behest of Ambassador Joseph Farland, Yeager was assigned as the Air Attache in Pakistan to advise the Pakistan Air Force which was led by Abdur Rahim Khan (the first Pakistani to break the sound barrier).", "He arrived in Pakistan at a time when tensions with India were at a high level.", "One of Yeager's jobs during this time was to assist Pakistani technicians in installing AIM-9 Sidewinders on PAF's Shenyang F-6 fighters.", "He also had a keen interest in interacting with PAF personnel from various Pakistani Squadrons and helping them develop combat tactics.", "In one instance in 1972, while visiting the No.", "15 Squadron \"Cobras\" at Peshawar Airbase, the Squadron's OC Wing Commander Najeeb Khan escorted him to K2 in a pair of F-86Fs after Yeager requested a visit to the second highest mountain on Earth.", "After hostilities broke out in 1971, he decided to stay in West Pakistan and continued overseeing the PAF's operations.", "Yeager recalled \"the Pakistanis whipped the Indians' asses in the sky... the Pakistanis scored a three-to-one kill ratio, knocking out 102 Russian-made Indian jets and losing 34 airplanes of their own\".", "During the war, he flew around the western front in a helicopter documenting wreckages of Indian warplanes of Soviet origin which included Sukhoi Su-7s and MiG-21s; they were transported to the United States after the war for analysis.", "Yeager also flew around in his Beechcraft Queen Air, a small passenger aircraft that was assigned to him by the Pentagon, picking up shot-down Indian fighter pilots.", "The Beechcraft was later destroyed during an air raid by the Indian Air Force at a PAF airbase.", "Yeager was not present in the aircraft.", "Edward C. Ingraham, a U.S. diplomat who had served as political counselor to Ambassador Farland in Islamabad, recalled this incident in the ''Washington Monthly'' of October 1985: \"After Yeager's Beechcraft was destroyed during an Indian air raid, he raged to his cowering colleagues that the Indian pilot had been specifically instructed by Indira Gandhi to blast his plane.", "'It was', he later wrote, 'the Indian way of giving Uncle Sam the finger'\".", "Yeager was incensed over the incident and demanded U.S. retaliation.=== Post-retirement career ===Brigadier General Yeager in 2000On March 1, 1975, following assignments in West Germany and Pakistan, Yeager retired from the Air Force at Norton Air Force Base, California.Yeager made a cameo appearance in the movie ''The Right Stuff'' (1983).", "He played \"Fred\", a bartender at \"Pancho's Place\", which was most appropriate, as Yeager said, \"if all the hours were ever totaled, I reckon I spent more time at her place than in a cockpit over those years\".", "Sam Shepard portrayed Yeager in the film, which chronicles in part his famous 1947 record-breaking flight.", "Also in popular culture, Yeager has been referenced several times as being part of the shared ''Star Trek'' universe, including having a fictional type of starship named after him and appearing in archival footage within the opening title sequence for the series ''Star Trek: Enterprise'' (2001–2005).", "For that same series, executive producer Rick Berman said that he envisaged the lead character, Captain Jonathan Archer, as being \"halfway between Chuck Yeager and Han Solo.", "\"For several years in the 1980s, Yeager was connected to General Motors, publicizing ACDelco, the company's automotive parts division.", "In 1986, he was invited to drive the Chevrolet Corvette pace car for the 70th running of the Indianapolis 500.In 1988, Yeager was again invited to drive the pace car, this time at the wheel of an Oldsmobile Cutlass Supreme.", "In 1986, President Reagan appointed Yeager to the Rogers Commission that investigated the explosion of the Space Shuttle ''Challenger''.During this time, Yeager also served as a technical adviser for three Electronic Arts flight simulator video games.", "The games include ''Chuck Yeager's Advanced Flight Trainer'', ''Chuck Yeager's Advanced Flight Trainer 2.0'', and ''Chuck Yeager's Air Combat''.", "The game manuals featured quotes and anecdotes from Yeager and were well received by players.", "Missions featured several of Yeager's accomplishments and let players attempt to top his records.", "''Chuck Yeager's Advanced Flight Trainer'' was Electronic Art's top-selling game for 1987.In 2009, Yeager participated in the documentary ''The Legend of Pancho Barnes and the Happy Bottom Riding Club'', a profile of his friend Pancho Barnes.", "The documentary was screened at film festivals, aired on public television in the United States, and won an Emmy Award.On October 14, 1997, on the 50th anniversary of his historic flight past Mach 1, he flew a new ''Glamorous Glennis III'', an F-15D Eagle, past Mach 1.The chase plane for the flight was an F-16 Fighting Falcon piloted by Bob Hoover, a longtime test, fighter, and aerobatic pilot who had been Yeager's wingman for the first supersonic flight.", "At the end of his speech to the crowd in 1997, Yeager concluded, \"All that I am ...", "I owe to the Air Force\".", "Later that month, he was the recipient of the Tony Jannus Award for his achievements.On October 14, 2012, on the 65th anniversary of breaking the sound barrier, Yeager did it again at the age of 89, flying as co-pilot in a McDonnell Douglas F-15 Eagle piloted by Captain David Vincent out of Nellis Air Force Base." ], [ "Awards and decorations", "Special Congressional Silver Medal awarded to Yeager in 1976In 1973, Yeager was inducted into the National Aviation Hall of Fame, arguably aviation's highest honor.", "In 1974, Yeager received the Golden Plate Award of the American Academy of Achievement.", "In December 1975, the U.S. Congress awarded Yeager a silver medal \"equivalent to a noncombat Medal of Honor ... for contributing immeasurably to aerospace science by risking his life in piloting the X-1 research airplane faster than the speed of sound on October 14, 1947\".", "President Gerald Ford presented the medal to Yeager in a ceremony at the White House on December 8, 1976.Yeager, who never attended college and was often modest about his background, is considered by many, including ''Flying Magazine'', the California Hall of Fame, the State of West Virginia, National Aviation Hall of Fame, a few U.S. presidents, and the United States Army Air Force, to be one of the greatest pilots of all time.", "''Air & Space/Smithsonian'' magazine ranked him the fifth greatest pilot of all time in 2003.Despite his lack of higher education, West Virginia's Marshall University named its highest academic scholarship the Society of Yeager Scholars in his honor.", "Yeager was also the chairman of Experimental Aircraft Association (EAA)'s Young Eagle Program from 1994 to 2004, and was named the program's chairman emeritus.In 1966, Yeager was inducted into the International Air & Space Hall of Fame.", "He was inducted into the International Space Hall of Fame in 1981.He was inducted into the Aerospace Walk of Honor 1990 inaugural class.Yeager Airport in Charleston, West Virginia, is named in his honor.", "The Interstate 64/Interstate 77 bridge over the Kanawha River in Charleston is named in his honor.", "He also flew directly under the Kanawha Bridge and West Virginia named it the Chuck E. Yeager Bridge.", "On October 19, 2006, the state of West Virginia also honored Yeager with a marker along Corridor G (part of U.S. Highway 119) in his home Lincoln County, and also renamed part of the highway the ''Yeager Highway''.Yeager was an honorary board member of the humanitarian organization Wings of Hope.", "On August 25, 2009, Governor Arnold Schwarzenegger and Maria Shriver announced that Yeager would be one of 13 California Hall of Fame inductees in The California Museum's yearlong exhibit.", "The induction ceremony was on December 1, 2009, in Sacramento, California.", "''Flying Magazine'' ranked Yeager number 5 on its 2013 list of The 51 Heroes of Aviation; for many years, he was the highest-ranked living person on the list.The Civil Air Patrol, the volunteer auxiliary of the USAF, awards the Charles E. \"Chuck\" Yeager Award to its senior members as part of its Aerospace Education program.", "'''Badges, patches and tabs'''100pxU.S.", "Air Force Command Pilot Badge'''Personal decorations'''Air Force Distinguished Service Medal (retirement award in 1975)Distinguished Service Medal (Army design awarded in 1954)Silver Star with bronze oak leaf cluster (for shooting down five Messerschmitt Bf 109s in one day)Legion of Merit with bronze oak leaf clusterDistinguished Flying Cross with two bronze oak leaf clusters (for a Messerschmitt Me 262 kill and first to break the sound barrier)Bronze Star Medal with bronze valor device (for helping rescue a fellow airman from Occupied France)Purple HeartAir Medal with two silver oak leaf clustersAir Force Commendation MedalPresidential Medal of Freedom'''Unit awards'''Presidential Unit Citation with bronze oak leaf clusterAir Force Outstanding Unit Award'''Campaign and service medals'''American Defense Service MedalAmerican Campaign MedalEuropean-African-Middle Eastern Campaign Medal with silver and one bronze service starWorld War II Victory MedalArmy of Occupation Medal with \"Germany\" claspNational Defense Service Medal with starArmed Forces Expeditionary MedalVietnam Service Medal with two campaign starsAir Force Longevity Service Ribbon with one silver and one bronze oak leaf clustersAir Force Small Arms Expert Marksmanship Ribbon'''Foreign awards'''60pxTongil Medal of the South Korean Order of National Security Merit60pxChevalier of the French Legion of Honour60pxRepublic of Vietnam Gallantry Cross Unit Citation60pxRepublic of Vietnam Campaign Medal=== Other achievements ===Old emblem of the General Chuck Yeager Cadet Squadron (formerly of the Civil Air Patrol)* 1940–1949 – Harmon Trophy: Citation of Honorable Mention* 1947 – Collier Trophy and Mackay Trophy, for breaking the sound barrier for the first time.", "* 1953 – Harmon Trophy* 1976 – Congressional Silver Medal" ], [ "Dates of rank", " Insignia Rank Service and Component Dateno insignia at the time Private United States ArmyRegular Army(Army Air Corps) September 12, 194135px35px Private first class to corporal United States ArmyRegular Army(Army Air Forces) 1941 to March 9, 194315px Flight officer United States ArmyArmy of the United States(Army Air Forces) March 10, 194314px Second lieutenant United States ArmyArmy of the United States(Army Air Forces) July 6, 194415px First lieutenant United States ArmyArmy of the United States(Army Air Forces) September 4, 194435px Captain United States ArmyArmy of the United States(Army Air Forces) October 24, 194414px Second lieutenant United States ArmyRegular Army(Army Air Forces) February 10, 1947(accepted February 25, 1947, rank from July 6, 1944)15px First lieutenant United States ArmyRegular Army(Army Air Forces) July 6, 1947 Captain United States Air Force July 6, 1951 Major United States Air Force February 15, 1951 (temporary)July 6, 1958 (permanent) Lieutenant colonel United States Air Force March 22, 1956 (temporary)August 1, 1964 (permanent) Colonel United States Air Force March 14, 1961 (temporary)September 20, 1967 (permanent) Brigadier general United States Air Force June 22, 1969" ], [ "Aerial victory credits", "Date # Type Location Aircraft flown Unit AssignedMarch 4, 19441 Messerschmitt Bf 109Kassel, GermanyP-51363 FS, 357 FGSeptember 13, 19440.5 Bf 109Kassel, GermanyP-51363 FS, 357 FGOctober 12, 19445 Bf 109Hanover, GermanyP-51363 FS, 357 FGNovember 6, 19441 Messerschmitt Me 262Assen, GermanyP-51363 FS, 357 FGNovember 27, 19444 Focke-Wulf Fw 190Magdeburg, GermanyP-51363 FS, 357 FG::::SOURCES: ''Air Force Historical Study 85: USAF Credits for the Destruction of Enemy Aircraft, World War II''" ], [ "Personal life", "F-15D EagleYeager named his plane after his wife, Glennis, as a good-luck charm: \"You're my good-luck charm, hon.", "Any airplane I name after you always brings me home.\"", "Yeager and Glennis moved to Grass Valley, California, after his retirement from the Air Force in 1975.The couple prospered as a result of Yeager's best-selling autobiography, speaking engagements, and commercial ventures.", "Glennis Yeager died of ovarian cancer in 1990.They had four children (Susan, Don, Mickey, and Sharon).", "Yeager's son Mickey (Michael) died unexpectedly in Oregon, on March 26, 2011.Yeager appeared in a Texas advertisement for George H. W. Bush's 1988 presidential campaign.In 2000, Yeager met actress Victoria Scott D'Angelo on a hiking trail in Nevada County.", "The pair started dating shortly thereafter, and married in August 2003.Subsequent to the commencement of their relationship, a bitter dispute arose between Yeager, his children and D'Angelo.", "The children contended that D'Angelo, at least 35 years Yeager's junior, had married him for his fortune.", "Yeager and D'Angelo both denied the charge.", "Litigation ensued, in which his children accused D'Angelo of \"undue influence\" on Yeager, and Yeager accused his children of diverting millions of dollars from his assets.", "In August 2008, the California Court of Appeal ruled for Yeager, finding that his daughter Susan had breached her duty as trustee.Yeager lived in Grass Valley, Northern California and died in the afternoon of December 7, 2020 (National Pearl Harbor Remembrance Day), at age 97, in a Los Angeles hospital.", "Following his death, President Donald Trump issued a statement of condolences stating Yeager \"was one of the greatest pilots in history, a proud West Virginian, and an American original who relentlessly pushed the boundaries of human achievement.\"" ], [ "See also", "* History of aviation* List of firsts in aviation* Society of Experimental Test Pilots" ], [ "Notes" ], [ "References" ], [ "Further reading", "* * * Wolfe, Tom ''The Right Stuff'' New York: Farrar-Straus-Giroux, 1979 * Yeager, Chuck, Bob Cardenas, Bob Hoover, Jack Russell and James Young ''The Quest for Mach One: A First-Person Account of Breaking the Sound Barrier'' New York: Penguin Studio, 1997 * Yeager, Chuck and Leo Janos, ''Yeager: An Autobiography'' New York: Bantam, 1985" ], [ "External links", "* * Biography from ChuckYeager.org* U.S. Air Force: Chuck Yeager biography* Yeager in Biography.com* Biography in the National Aviation Hall of Fame * General Chuck Yeager, USAF, Biography and Interview with the American Academy of Achievement* * ''Airport Journals''' \"Chuck Yeager: Booming And Zooming\" Part 1 and Part 2* \"Chuck Yeager & the Sound Barrier\" in Aerospaceweb.org* Space.com: Chuck Yeager* * * Yeager obituary via ''The New York Times''" ] ]
wikipedia
[ [ "Cajun cuisine" ], [ "Introduction", "Cornbread is a staple Cajun starch.", "'''Cajun cuisine''' ( , ) is a style of cooking developed by the Cajun–Acadians who were deported from Acadia to Louisiana during the 18th century and who incorporated West African, French and Spanish cooking techniques into their original cuisine.", "Cajun cuisine is sometimes referred to as a 'rustic cuisine', meaning that it is based on locally available ingredients and that preparation is relatively simple.An authentic Cajun meal is usually a three-pot affair, with one pot dedicated to the main dish, one dedicated to steamed rice, specially made sausages, or some seafood dish, and the third containing whatever vegetable is plentiful or available.", "Crawfish, shrimp, and andouille sausage are staple meats used in a variety of dishes.The aromatic vegetables green bell pepper (), onion, and celery are called \"the trinity\" by chefs in Cajun and Louisiana Creole cuisines.", "Roughly diced and combined in cooking, the method is similar to the use of the ''mirepoix'' in traditional French cuisine which blends roughly diced carrot, onion, and celery.", "Additional characteristic aromatics for both the Creole and Cajun versions may include parsley, bay leaf, thyme, green onions, ground cayenne pepper, and ground black pepper.", "Cayenne and Louisiana-style hot sauce are the primary sources of spice in Cajun cuisine, which usually tends towards a moderate, well-balanced heat, despite the national \"Cajun hot\" craze of the 1980s and 1990s." ], [ "History", "The Acadians were a group of French colonists who lived in Acadia, what is today Eastern Canada.", "In the mid-18th century, they were deported from Acadia by the British during the French and Indian War in what they termed ''le Grand Dérangement'', and many of them ended up settling in Southern Louisiana.", "Due to the extreme change in climate, Acadians were unable to cook their original dishes.", "Soon, their former culinary traditions were adapted and, in time, incorporated not only Indigenous American traditions, but also African-American traditions—as is exemplified in the classic Cajun dish \"Gumbo\", which is named for its principal ingredient (Okra) using the West African name for that very ingredient: \"Gumbo,\" in West Africa, means \"Okra\".", "Many other meals developed along these lines, adapted in no small part from Haiti, to become what is now considered classic Cajun cuisine traditions (not to be confused with the more modern concept associated with Prudhomme's style).", "Up through the 20th century, the meals were not elaborate but instead, rather basic.", "The public's false perception of \"Cajun\" cuisine was based on Prudhomme's style of Cajun cooking, which was spicy, flavorful, and not true to the classic form of the cuisine.", "Cajun and Creole cuisine have been mistaken to be the same, but the origins of Creole cooking began in New Orleans, and Cajun cooking came 40 years after the establishment of New Orleans.", "Today, most restaurants serve dishes that consist of Cajun styles, which Paul Prudhomme dubbed \"Louisiana cooking\".", "In home-cooking, these individual styles are still kept separate.", "However, there are fewer and fewer people cooking the classic Cajun dishes that would have been eaten by the original settlers." ], [ "Cajun cooking methods", "*Barbecuing—similar to \"low and slow\" Southern barbecue traditions, but with Creole/Cajun seasoning.", "A classic example is Johnson's Boucaniere (\"smokehouse\") in Lafayette, which was named best barbecue in Louisiana by the Food Network in July 2022.In the Ville Platte area, a unique sauce is made from dried onions reconstituted in water and vegetable oil thick with ketchup, mustard, Worcestershire sauce, and seasonings.", "The flavorful oil that rises to the top is applied directly to meats being cooked as a baste.", "Two popular brands are Jack Miller's and Pig Stand, which are available online and in grocery stores across the state.", "This sauce is also commonly used on hamburgers, hot dogs, pork chops, chicken, and other grilled items.", "*Baking—direct and indirect dry heat in a furnace or oven, faster than smoking but slower than grilling*Grilling—direct heat on a shallow surface, fastest of all variants; sub-variants include:**Charbroiling—direct dry heat on a solid surface with wide raised ridges**Gridironing—direct dry heat on a solid or hollow surface with narrow raised ridges**Griddling—direct dry or moist heat along with the use of oils and butter on a flat surface*Braising—combining a direct dry heat charbroil-grill or gridiron-grill with a pot filled with broth for direct moist heat, faster than smoking but slower than regular grilling and baking; time starts fast, slows down, then speeds up again to finish*Boiling—as in boiling of crabs, crawfish, or shrimp, in seasoned liquid, often with side items like corn on the cob, whole new potatoes, and mushrooms cooked in the same boiling pot.", "A seafood boil is often a large outdoor social event.", "*Deep frying—lightly breaded and fried seafood including various fish, shrimp, oysters, and soft-shell crab is universally popular in Cajun cuisine, often on French bread po-boys in the New Orleans style, along with traditional Southern favorites like fried chicken, fried okra, and pork chops.", "*Smothering—cooking a vegetable or meat over low heat with the sauteed \"trinity,\" plus small amounts of water or stock, similar to braising.", "This forms a pan sauce or gravy, and the finished product is served over rice.", "''Étouffée'' is a popular variant done with crawfish or shrimp.", "A meatless version might feature mushrooms and eggplant.", "Two commonly smothered meats are pork chops and round steak; these heartier meats may sometimes have a bit of roux added to the gravy.", "*Pan-broiling or pan-frying*Injecting—using a large syringe-type setup to place seasoning deep inside large cuts of meat; this technique is much newer than the others on this list, but very common in Cajun cuisine*Stewing, also known as ; a whole chicken cut into pieces is a popular choice for this method, particularly an older hen.Deep-frying of turkeys or oven-roasted turduckens entered southern Louisiana cuisine more recently.", "Also, blackening of fish or chicken and barbecuing of shrimp in the shell are excluded because they were not prepared in traditional Cajun cuisine.", "Blackening was actually an invention by chef Paul Prudhomme in the 1970s, becoming associated with Cajun cooking, and presented as such by him, but is not a true historical or traditional Cajun cooking process." ], [ "Ingredients", "The following is a partial list of ingredients used in Cajun cuisine and some of the staple ingredients of the Acadian food culture.===Grains===*Corn*Rice*Scotch barley*Wheat—for baking bread===Fruits and vegetables===*Bell peppers (green or red)*Blackberries*Cayenne peppers*Celery (seed, leaf and stalk)*Collard greens*Cucumbers*Figs*Leek*Limes*Lemons*Mirlitons (chayotes or vegetable pears)*Muscadines*Okra*Onions*Parsnip*Parsley*Pecans*Satsuma oranges*Scallions (green onions or onion tops)*Squash*Strawberries*Sweet potatoes*Tabasco pepper*Tomatoes===Meat and seafood===Cajun foodways include many ways of preserving meat, some of which are waning due to the availability of refrigeration and mass-produced meat at the grocer.", "Smoking of meats remains a fairly common practice, but once-common preparations such as turkey or duck confit (preserved in poultry fat, with spices) are now seen even by Acadians as quaint rarities.Game (and hunting) are still uniformly popular in Acadiana.The recent increase of catfish farming in the Mississippi Delta has brought about an increase in its usage in Cajun cuisine in place of the more traditional wild-caught trout.", "'''Seafood'''*Freshwater **Bass **Catfish**Sac-à-lait (white perch or crappie)**Yellow perch*Saltwater or brackish water species**Trout**Redfish**Pompano**Drumfish**Flounder**Grouper**Perch—many varieties**Snapper—many varieties*Shellfish**Crawfish (''écrevisse'')—either wild swamp or farm-raised**Shrimp, or ''crevette'' (''chevrette'' in Louisiana French)**Oysters**Blue crabAlso included in the seafood mix are some so-called trash fish that would not sell at the market because of their high bone to meat ratio or required complicated cooking methods.", "These were brought home by fishermen to feed the family.", "Examples are garfish, black drum also called ''gaspergou'' or just \"goo\", croaker, and bream.", "'''Poultry'''*Farm-raised**Turkey (and turkey confit)**Chicken (and guinea hen)*Game birds**Dove**Duck (and duck confit)**Goose**Quail'''Pork'''*''Andouille''—a spicy smoked pork sausage, characterized by a coarse-ground texture and large-diameter casing.", "*''Boudin''—a cooked sausage made with green onions, pork, and rice, and usually a large amount of ground pork or chicken livers.", "Boudin may be thought of as \"dirty rice in a casing.\"", "Some locals prefer to eat the sausage with the casing on, while others squeeze the contents out.", "Boudin filling is completely cooked before being stuffed into casings and may be consumed immediately after purchase, although it is also popularly grilled at cookouts.", "Pork blood is sometimes added to produce ''boudin rouge''.", "Other versions can contain seafood, such as crawfish.", "*''Chaurice'', a sausage similar to Spanish ''chorizo''*''Chaudin'' or ''ponce''—a pig's stomach, stuffed with spiced pork & smoked.", "*Ham hocks*Wild boar or feral hog*Head cheese*Gratons—hog cracklings or pork rinds; fried, seasoned pork fat & skin, sometimes with small bits of meat attached.", "Similar to Spanish ''chicharrones''.", "* New Orleans hot sausage—a spiced pork or beef sausage characterized by a reddish color.", "*Pork sausage (fresh)—distinctively seasoned and usually smoked, this sausage is often used in gumbos as is andouille, but it may also be grilled or pan-cooked to produce a rice and gravy dish.", "The sausage itself does not include rice, separating it from ''boudin''.", "In Cajun country, a distinction exists between this sausage, which is simply called \"pork sausage,\" is finer ground, and uses smaller pork casings, and the similar andouille, which has a coarser grind and larger beef casings.", "*Salt pork*Tasso—a highly seasoned, smoked pork shoulder of the Choctaw'''Beef and dairy'''Though parts of Acadiana are well suited to cattle or dairy farming, beef is not often used in a pre-processed or uniquely Cajun form.", "It is usually prepared fairly simply as chops, stews, or steaks, taking a cue from Texas to the west.", "Ground beef is used as is traditional throughout the US, although seasoned differently.Dairy farming is not as prevalent as in the past, but there are still some farms in the business.", "There are no unique dairy items prepared in Cajun cuisine.", "Traditional Cajun and New Orleans Creole-influenced desserts are common.", "'''Other game meats'''*Alligator*Alligator gar, or gator gar*Frog, usually bullfrogs (not just the legs, but the entire creature)*''Gros bec'', commonly called night heron*Nutria*Squirrel*Rabbit*Skunk, or ''bête puante''*Turtle*Snake*Virginia opossum, or ''rat de bois''*VenisonCajun woman reaching for strings of garlic suspended from rafters.", "Near Crowley, Louisiana, 1938.===Seasonings===*Basil*Bay leaf*Black pepper*Cayenne pepper*Chili pepper*Chervil*Chives*Cloves*Dried shrimp*Garlic*Green mint*Marjoram*Onion (bell pepper, onion, and celery used together are known as the \"holy trinity\" of Cajun cuisine)*Oregano*Parsley, flat leaf*Sage*Sassafras leaves (dried & ground into the spice known as filé for gumbo of the Choctaw)*Sugarcane, also cane syrup, brown sugar and molasses*Summer savory*ThymeThyme, sage, mint, marjoram, savory, and basil are considered sweet herbs.", "In Colonial times a herbes de Provence would be several sweet herbs tied up in a muslin.====Blended====*\"Creole/Cajun spice\" blends such as Tony Chachere's are sometimes used in Cajun kitchens, but do not suit every cook's style because Creole- and Cajun-style seasoning is often achieved from scratch, even by taste.", ":Cajun seasonings consist of a blend of salt with a variety of spices, most common being cayenne pepper and garlic.", "The spicy heat comes from the cayenne pepper, while other flavors come from bell pepper, paprika, green onions, parsley and more.", "*Curry*Hot sauce, including Tabasco sauce, which by 1885 was well known in Louisiana and abroad.", "*Marinades made with olive oil, brown sugar, and citrus juices*Mushroom catsup*Persillade*Seafood boil mix*Various barbecue rubs similar to those in other states.", "*Vinegar seasoned with small, pickled, hot green peppers is a common condiment with many Cajun meals.", "*Walnut catsup*Worcestershire sauce===Cooking bases===*Dark roux—Cajuns inherited roux from the French.", "However, unlike the French, theirs is made with oil or bacon fat and more lately with olive oil, and not normally with butter.", "It is used as a thickening agent, especially in gumbo and ''étouffée''.", ":Preparation of a dark roux is probably the most involved or complicated procedure in Cajun cuisine, involving heating fat and flour very carefully, constantly stirring for about 15–45 minutes (depending on the color of the desired product), until the mixture has darkened in color and developed a nutty flavor.", "The temperature should not be too high, as a burnt roux renders a dish unpalatable.", "*Light roux—The secret to making a good gumbo is pairing the roux with the protein.", "A dark roux, with its strong (dense) nutty flavor will completely overpower a simple seafood gumbo, but is the perfect complement to a gumbo using chicken, sausage, crawfish or alligator.", ":A light roux, on the other hand, is better suited for strictly seafood dishes and unsuitable for meat gumbos for the reason that it does not support the heavier meat flavor as well.", "Pairing roux with protein follows the same orthodox philosophy as pairing wine with protein.", "*Stocks: Cajun stocks are more heavily seasoned than Continental counterparts, and the shellfish stock sometimes made with shrimp and crawfish heads is unique to Cajun cuisine.", "**Fish stock and Court-bouillon**Shellfish stock**Chicken stock" ], [ "Cajun dishes", "===Primary favorites===smokedSeafood gumbo'''Boudin'''—a type of sausage made from pork, pork liver, rice, garlic, green onions and other spices.", "It is widely available by the link or pound from butcher shops.", "''Boudin'' is typically stuffed in a natural casing and has a softer consistency than other, better-known sausage varieties.", "It is usually served with side dishes such as rice dressing, ''maque choux'' or bread.", "''Boudin'' balls are commonly served in southern Louisiana restaurants and are made by taking the ''boudin'' out of the case and frying it in spherical form.", "'''Gumbo'''—High on the list of favorites of Cajun cooking are the soups called gumbos.", "Contrary to non-Cajun or Continental beliefs, gumbo does not mean simply \"everything in the pot\".", "Gumbo exemplifies the influence of French, Spanish, African and Native American food cultures on Cajun cuisine.", "There are two theories as to the etymological origins of the name.", "\"Some believe that gumbo gets its name from the Choctaw word for filé powder, kombo; others suggest it's taken from the West African Bantu name for okra, ki ngombo.\"", "Both filé and okra can be used as thickening agents in gumbo.", "Historically, large amounts of filé were added directly to the pot when okra was out of season.", "While a distinction between filé gumbo and okra gumbo is still held by some, many people enjoy putting filé in okra gumbo simply as a flavoring.", "Regardless of which is the dominant thickener, filé is also provided at the table and added to taste.Many claim that gumbo is a Cajun dish, but gumbo was established long before the Acadian arrival.", "Its early existence came via the early French Creole culture in New Orleans, Louisiana, where French, Spanish and Africans frequented and also influenced by later waves of Italian, German and Irish settlers.The backbone of a gumbo is roux, as described above.", "Cajun gumbo typically favors darker roux, often approaching the color of chocolate or coffee beans.", "Since the starches in the flour break down more with longer cooking time, a dark roux has less thickening power than a lighter one.", "While the stovetop method is traditional, flour may also be dry-toasted in an oven for a fat-free roux, or a regular roux may be prepared in a microwave oven for a hands-off method.", "If the roux is for immediate use, the \"trinity\" may be sauteed in it, which stops the cooking process.A classic gumbo is made with chicken and andouille, especially in the colder months, but the ingredients vary according to what is available.", "Seafood gumbos are also very popular in Cajun country.", "'''Jambalaya'''—The only certain thing that can be said about jambalaya is that it contains rice, some sort of meat (often chicken, ham, sausage, or a combination), seafood (such as shrimp or crawfish), plus other items that may be available.", "Usually, it will include green peppers, onions, celery, tomatoes and hot chili peppers.", "This is also a great pre-Acadian dish, established by the Spanish in Louisiana.", "Jambalaya may be a tomato-rich New Orleans-style \"red\" jambalaya of Spanish Creole roots, or a Cajun-style \"brown\" jambalaya which draws its color and flavor from browned meat and caramelized onions.", "Historically, tomatoes were not as widely available in Acadiana as the area around New Orleans, but in modern times, both styles are popular across the state.", "Brown is the style served at the annual World Jambalaya Festival in Gonzales.", "'''Rice and gravy'''—Rice and gravy dishes are a staple of Cajun cuisine and is usually a brown gravy based on pan drippings, which are deglazed and simmered with extra seasonings and served over steamed or boiled rice.", "The dish is traditionally made from cheaper cuts of meat and cooked in a cast-iron pot, typically for an extended time period to let the tough cuts of meat become tender.", "Beef, pork, chicken or any of a large variety of game meats are used for its preparation.", "Popular local varieties include hamburger steak, smothered rabbit, turkey necks, and chicken fricassee.===Food as an event=======Crawfish boil====Louisiana-style crawfish boilThe crawfish boil is a celebratory event where Cajuns boil crawfish, potatoes, onions and corn in large pots over propane cookers.", "Lemons and small muslin bags containing a mixture of bay leaves, mustard seeds, cayenne pepper, and other spices, commonly known as \"crab boil\" or \"crawfish boil\" are added to the water for seasoning.", "The results are then dumped onto large, newspaper-draped tables and in some areas covered in Creole/Cajun spice blends, such as REX, Zatarain's, Louisiana Fish Fry, or Tony Chachere's.", "Also, cocktail sauce, mayonnaise, and hot sauce are sometimes used.", "The seafood is scooped onto large trays or plates and eaten by hand.", "During times when crawfish are not abundant, shrimp and crabs are prepared and served in the same manner.Attendees are encouraged to \"suck the head\" of a crawfish by separating the head from the abdomen of the crustacean and sucking out the fat and juices from the head.Often, newcomers to the crawfish boil or those unfamiliar with the traditions are jokingly warned \"not to eat the dead ones.\"", "This comes from the common belief that when live crawfish are boiled, their tails curl beneath themselves, but when dead crawfish are boiled, their tails are straight and limp.Seafood boils with crabs and shrimp are also popular.====Family ====A traditional near Eunice, LouisianaThe traditional Cajun outdoor food event is hosted by a farmer in the rural areas of Acadiana.", "Family and friends of the farmer gather to socialize, play games, dance, drink, and have a copious meal consisting of hog and other dishes.", "Men have the task of slaughtering a hog, cutting it into usable parts, and cooking the main pork dishes while women have the task of making boudin.========Similar to a family , the is a food event that revolves around pork but does not need to be hosted by a farmer.", "Traditionally, a suckling pig was purchased for the event, but in modern , adult pigs are used.Unlike the family , a hog is not butchered by the hosts and there are generally not as many guests or activities.", "The host and male guests have the task of roasting the pig (see pig roast) while female guests bring side dishes.====Rural Mardi Gras====The traditional Cajun Mardi Gras (see: ''Courir de Mardi Gras'') is a Mardi Gras celebration in rural Cajun Parishes.", "The tradition originated in the 18th century with the Cajuns of Louisiana, but it was abandoned in the early 20th century because of unwelcome violence associated with the event.", "In the early 1950s the tradition was revived in Mamou in Evangeline Parish.The event revolves around male maskers on horseback who ride into the countryside to collect food ingredients for the party later on.", "They entertain householders with Cajun music, dancing, and festive antics in return for the ingredients.", "The preferred ingredient is a live chicken in which the householder throws the chicken to allow the maskers to chase it down (symbolizing a hunt), but other ingredients include rice, sausage, vegetables, or frozen chicken.", "Unlike other Cajun events, men take no part in cooking the main course for the party, and women prepare the chicken and ingredients for the gumbo.", "Once the festivities begin, the Cajun community members eat and dance to Cajun music until midnight after which is the beginning of Lent.===Other dishes and sides===Boudin balls* Alligator meat* Andouille sausage* Boiled crawfish* ''Boudin'' balls—''Boudin'' sausage filling that is rolled into a ball, battered and deep fried, instead of being stuffed into pork casings.", "* Brochette* Creole rice* Catfish (or redfish) court-bouillon* Cochon de lait—suckling pig* Couche couche (Creole corn mush)* Crawfish bisque* Crawfish ''étouffée''* Crawfish pie* Dirty rice* ''Étouffée''* Fried frog legs* Gumbo z'herbes * Hog's head cheese* Maque choux* Pecan pralines* Pepper jelly* Potato salad—generally made with egg, potato, celery, onions, mayonnaise, mustard and sometimes bell pepper* Seafood-stuffed ''mirliton''* Tarte à la Bouillie—sweet-dough custard tarts* Tasso ham" ], [ "List of Cajun-influenced chefs", "* Frank Joseph Davis* John Folse* Emeril Lagasse* Paul Prudhomme* Justin Wilson* Isaac Toups" ], [ "In popular culture", "Three popular local dishes in Acadiana are noted in the Hank Williams song \"Jambalaya\", namely \"Jambalaya and-a crawfish pie and filé gumbo\"." ], [ "See also", "* Cuisine of New Orleans* Cuisine of the United States* List of festivals in Louisiana* Louisiana Creole cuisine*Acadian cuisine" ], [ "References" ], [ "External links" ] ]
wikipedia
[ [ "Cologne" ], [ "Introduction", "'''Cologne''' ( ; ; ) is the largest city of the German state of North Rhine-Westphalia and the fourth-most populous city of Germany with nearly 1.1 million inhabitants in the city proper and over 3.1 million people in the Cologne Bonn urban region.", "Cologne is also part of the Rhine-Ruhr metropolitan region, the second biggest metropolitan region by GDP in the European Union.", "Centered on the left (west) bank of the Rhine, Cologne is about southeast of the North Rhine-Westphalia state capital Düsseldorf and northwest of Bonn, the former capital of West Germany.The city's medieval Cologne Cathedral () is the third-tallest church and tallest cathedral in the world.", "It was constructed to house the Shrine of the Three Kings and is a globally recognized landmark and one of the most visited sights and pilgrimage destinations in Europe.", "The cityscape is further shaped by the Twelve Romanesque churches of Cologne.", "Cologne is famous for Eau de Cologne, which has been produced in the city since 1709; \"cologne\" has since come to be a generic term.Cologne was founded and established in Germanic Ubii territory in the 1st century CE as the Roman , hence its name.", "was later dropped (except in Latin), and became the name of the city in its own right, which developed into modern German as .", ", the French version of the city's name, has become standard in English as well.", "Cologne functioned as the capital of the Roman province of and as the headquarters of the Roman military in the region until occupied by the Franks in 462.During the Middle Ages the city flourished as being located on one of the most important major trade routes between east and western Europe (including the Brabant Road, Via Regia and Publica).", "Cologne was a free imperial city of the Holy Roman Empire and one of the major members of the trade union Hanseatic League.", "It was one of the largest European cities in medieval and renaissance times.Prior to World War II, the city had undergone occupations by the French (1794–1815) and the British (1918–1926), and was part of Prussia beginning in 1815.Cologne was one of the most heavily bombed cities in Germany during World War II.", "The bombing reduced the population by 93% mainly due to evacuation, and destroyed around 80% of the millennia-old city center.", "The post-war rebuilding has resulted in a mixed cityscape, restoring most major historic landmarks like city gates and churches (31 of them being Romanesque).", "The city boasts around 9,000 historic buildings.Cologne is a major cultural center for the Rhineland; it hosts more than 30 museums and hundreds of galleries.", "There are many institutions of higher education, most notably the University of Cologne, one of Europe's oldest and largest universities; the Technical University of Cologne, Germany's largest university of applied sciences; and the German Sport University Cologne.", "It hosts three Max Planck science institutes and is a major research hub for the aerospace industry, with the German Aerospace Center and the European Astronaut Centre headquarters.", "Lufthansa, Europe´s largest airline, have their main corporate headquarters in Cologne.", "It also has a significant chemical and automobile industry.", "Cologne Bonn Airport is a regional hub, the main airport for the region being Düsseldorf Airport.", "The Cologne Trade Fair hosts a number of trade shows." ], [ "History", "===Roman Cologne===Dionysian scenes from a Roman villa of Cologne, Germany (site of the ancient city Colonia Claudia Ara Agrippinensium), 3rd century CE, Romano-Germanic MuseumThe first urban settlement on the grounds of modern-day Cologne was ''Oppidum Ubiorum'', founded in 38 BCE by the Ubii, a Cisrhenian Germanic tribe.", "In 50 CE, the Romans founded Colonia Claudia Ara Agrippinensium (Cologne) on the river Rhine and the city became the provincial capital of Germania Inferior in 85 CE.", "It was also known as .", "Considerable Roman remains can be found in present-day Cologne, especially near the wharf area, where a 1,900-year-old Roman boat was discovered in late 2007.From 260 to 271, Cologne was the capital of the Gallic Empire under Postumus, Marius, and Victorinus.", "In 310, under emperor Constantine I, a bridge was built over the Rhine at Cologne.", "Roman imperial governors resided in the city and it became one of the most important trade and production centers in the Roman Empire north of the Alps.", "Cologne is shown on the 4th century Peutinger Map.Maternus, who was elected as bishop in 313, was the first known bishop of Cologne.", "The city was the capital of a Roman province until it was occupied by the Ripuarian Franks in 462.Parts of the original Roman sewers are preserved underneath the city, with the new sewerage system having opened in 1890.After the destruction of the Second Temple in the Siege of Jerusalem and the associated dispersion (diaspora) of the Jews, there is evidence of a Jewish community in Cologne.", "In 321 CE, Emperor Constantine approved the settlement of a Jewish community with all the freedoms of Roman citizens.", "It is assumed that it was located near the Marspforte within the city wall.", "The Edict of Constantine to the Jews is the oldest documented evidence in Germany.===Middle Ages===Early medieval Cologne was part of Austrasia within the Frankish Empire.", "Cunibert, made bishop of Cologne in 623, was an important advisor to the Merovingian King Dagobert I and served with domesticus Pepin of Landen as tutor to the king's son and heir Siegebert III, the future king of Austrasia.", "In 716, Charles Martel commanded an army for the first time and suffered the only defeat of his life when Chilperic II, King of Neustria, invaded Austrasia and the city fell to him in the Battle of Cologne.", "Charles fled to the Eifel mountains, rallied supporters and took the city back that same year after defeating Chilperic in the Battle of Amblève.", "Cologne had been the seat of a bishop since the Roman period; under Charlemagne, in 795, bishop Hildebold was promoted to archbishop.", "In the 843 Treaty of Verdun Cologne fell into the dominion of Lothair I's Middle Francia – later called Lotharingia (Lower Lorraine).In 953, the archbishops of Cologne first gained noteworthy secular power when bishop Bruno was appointed as duke by his brother Otto I, King of Germany.", "In order to weaken the secular nobility, who threatened his power, Otto endowed Bruno and his archiepiscopal successors with the prerogatives of secular princes, thus establishing the Electorate of Cologne, formed by the temporal possessions of the archbishopric and included in the end a strip of territory along the left Bank of the Rhine east of Jülich, as well as the Duchy of Westphalia on the other side of the Rhine, beyond Berg and Mark.", "By the end of the 12th century, the Archbishop of Cologne was one of the seven electors of the Holy Roman Emperor.", "Besides being prince elector, he was Archchancellor of Italy as well, technically from 1238 and permanently from 1263 until 1803.Following the Battle of Worringen in 1288, Cologne gained its independence from the archbishops and became a Free City.", "Archbishop Sigfried II von Westerburg was forced to reside in Bonn.", "The archbishop nevertheless preserved the right of capital punishment.", "Thus the municipal council (though in strict political opposition towards the archbishop) depended upon him in all matters concerning criminal justice.", "This included torture, the sentence for which was only allowed to be handed down by the episcopal judge known as the greve.", "This legal situation lasted until the French conquest of Cologne.Besides its economic and political significance Cologne also became an important centre of medieval pilgrimage, when Cologne's archbishop, Rainald of Dassel, gave the relics of the Three Wise Men to Cologne's cathedral in 1164 (after they had been taken from Milan).", "Besides the three magi Cologne preserves the relics of Saint Ursula and Albertus Magnus.Cologne's location on the river Rhine placed it at the intersection of the major trade routes between east and west as well as the main south–north Western Europe trade route, Venice to Netherlands; even by the mid-10th century, merchants in the town were already known for their prosperity and luxurious standard of living due to the availability of trade opportunities.", "The intersection of these trade routes was the basis of Cologne's growth.", "By the end of the 12th century, Archbishop Phillip von Heinsberg enclosed the entire city with walls.", "By 1300 the city population was 50,000–55,000.Cologne was a member of the Hanseatic League in 1475, when Frederick III confirmed the city's imperial immediacy.", "Cologne was so influential in regional commerce that its systems of weights and measurements (e.g.", "the Cologne mark) were used throughout Europe.Cologne ===Early modern history===Panorama of Cologne in 1530Deutz by the Swedish army during the Thirty Years' War in 1632Reconstruction of Cologne in the 17th century (German, English subtitles available)The economic structures of medieval and early modern Cologne were characterised by the city's status as a major harbour and transport hub on the Rhine.", "Craftsmanship was organised by self-administering guilds, some of which were exclusive to women.As a free imperial city, Cologne was a self-ruling state within the Holy Roman Empire, an imperial estate with seat and vote at the Imperial Diet, and as such had the right (and obligation) to contribute to the defense of the Empire and maintain its own military force.", "As they wore a red uniform, these troops were known as the ''Rote Funken'' (red sparks).", "These soldiers were part of the Army of the Holy Roman Empire (\"Reichskontingent\").", "They fought in the wars of the 17th and 18th century, including the wars against revolutionary France in which the small force was almost completely wiped out in combat.", "The tradition of these troops is preserved as a military persiflage by Cologne's most outstanding carnival society, the ''Rote Funken''.The Free Imperial City of Cologne must not be confused with the Electorate of Cologne, which was a state of its own within the Holy Roman Empire.", "Since the second half of the 16th century the majority of archbishops were drawn from the Bavarian Wittelsbach dynasty.", "Due to the free status of Cologne, the archbishops were usually not allowed to enter the city.", "Thus they took up residence in Bonn and later in Brühl on the Rhine.", "As members of an influential and powerful family, and supported by their outstanding status as electors, the archbishops of Cologne repeatedly challenged and threatened the free status of Cologne during the 17th and 18th centuries, resulting in complicated affairs, which were handled by diplomatic means and propaganda as well as by the supreme courts of the Holy Roman Empire.===From the 19th century until World War II===Hanging bridgeCologne lost its status as a free city during the French period.", "According to the Treaty of Lunéville (1801) all the territories of the Holy Roman Empire on the left bank of the Rhine were officially incorporated into the French Republic (which had already occupied Cologne in 1794).", "Thus this region later became part of Napoleon's Empire.", "Cologne was part of the French Département Roer (named after the river Roer, German: Rur) with Aachen (French: Aix-la-Chapelle) as its capital.", "The French modernised public life, for example by introducing the Napoleonic code and removing the old elites from power.", "The Napoleonic code remained in use on the left bank of the Rhine until 1900, when a unified civil code (the ''Bürgerliches Gesetzbuch'') was introduced in the German Empire.", "In 1815 at the Congress of Vienna, Cologne was made part of the Kingdom of Prussia, first in the Province of Jülich-Cleves-Berg and then the Rhine Province.The permanent tensions between the Catholic Rhineland and the overwhelmingly Protestant Prussian state repeatedly escalated with Cologne being in the focus of the conflict.", "In 1837 the archbishop of Cologne, Clemens August von Droste-Vischering, was arrested and imprisoned for two years after a dispute over the legal status of marriages between Catholics and Protestants (''Mischehenstreit'').", "In 1874, during the Kulturkampf, Archbishop Paul Melchers was imprisoned before taking asylum in the Netherlands.", "These conflicts alienated the Catholic population from Berlin and contributed to a deeply felt anti-Prussian resentment, which was still significant after World War II, when the former mayor of Cologne, Konrad Adenauer, became the first West German chancellor.During the 19th and 20th centuries, Cologne absorbed numerous surrounding towns, and by World War I had already grown to 700,000 inhabitants.", "Industrialisation changed the city and spurred its growth.", "Vehicle and engine manufacturing was especially successful, though the heavy industry was less ubiquitous than in the Ruhr area.", "The cathedral, started in 1248 but abandoned around 1560, was eventually finished in 1880 not just as a place of worship but also as a German national monument celebrating the newly founded German empire and the continuity of the German nation since the Middle Ages.", "Some of this urban growth occurred at the expense of the city's historic heritage with much being demolished (for example, the city walls or the area around the cathedral) and sometimes replaced by contemporary buildings.Cologne was designated as one of the Fortresses of the German Confederation.", "It was turned into a heavily armed fortress (opposing the French and Belgian fortresses of Verdun and Liège) with two fortified belts surrounding the city, the remains of which can be seen to this day.", "The military demands on what became Germany's largest fortress presented a significant obstacle to urban development, with forts, bunkers, and wide defensive dugouts completely encircling the city and preventing expansion; this resulted in a very densely built-up area within the city itself.During World War I Cologne was the target of several minor air raids but suffered no significant damage.", "Cologne was occupied by the British Army of the Rhine until 1926, under the terms of the Armistice and the subsequent Versailles Peace Treaty.", "In contrast with the harsh behaviour of the French occupation troops in Germany, the British forces were more lenient to the local population.", "Konrad Adenauer, the mayor of Cologne from 1917 until 1933 and later a West German chancellor, acknowledged the political impact of this approach, especially since Britain had opposed French demands for a permanent Allied occupation of the entire Rhineland.As part of the demilitarisation of the Rhineland, the city's fortifications had to be dismantled.", "This was an opportunity to create two green belts (''Grüngürtel'') around the city by converting the fortifications and their fields of fire into large public parks.", "This was not completed until 1933.In 1919 the University of Cologne, closed by the French in 1798, was reopened.", "This was considered to be a replacement for the loss of the University of Strasbourg on the west bank of the Rhine, which reverted to France with the rest of Alsace.", "Cologne prospered during the Weimar Republic (1919–33), and progress was made especially in public governance, city planning, housing and social affairs.", "Social housing projects were considered exemplary and were copied by other German cities.", "Cologne competed to host the Olympics, and a modern sports stadium was erected at Müngersdorf.", "When the British occupation ended, the prohibition of civil aviation was lifted and Cologne Butzweilerhof Airport soon became a hub for national and international air traffic, second in Germany only to Berlin Tempelhof Airport.The democratic parties lost the local elections in Cologne in March 1933 to the Nazi Party and other extreme-right parties.", "The Nazis then arrested the Communist and Social Democrats members of the city assembly, and Mayor Adenauer was dismissed.", "Compared to some other major cities, however, the Nazis never gained decisive support in Cologne.", "(Significantly, the number of votes cast for the Nazi Party in Reichstag elections had always been the national average.)", "By 1939, the population had risen to 772,221 inhabitants.===World War II===The devastation of Cologne, 1945During World War II, Cologne was a Military Area Command Headquarters () for Wehrkreis VI (headquartered at Münster).", "Cologne was under the command of Lieutenant-General Freiherr Roeder von Diersburg, who was responsible for military operations in Bonn, Siegburg, Aachen, Jülich, Düren, and Monschau.", "Cologne was home to the 211th Infantry Regiment and the 26th Artillery Regiment.The Allies dropped 44,923.2 tons of bombs on the city during World War II, destroying 61% of its built up area.", "During the Bombing of Cologne in World War II, Cologne endured 262 air raids by the Western Allies, which caused approximately 20,000 civilian casualties and almost completely wiped out the central part of the city.", "During the night of 31 May 1942, Cologne was the target of \"Operation Millennium\", the first 1,000 bomber raid by the Royal Air Force in World War II.", "1,046 heavy bombers attacked their target with 1,455 tons of explosives, approximately two-thirds of which were incendiary.", "This raid lasted about 75 minutes, destroyed of built-up area (61%), killed 486 civilians and made 59,000 people homeless.", "The devastation was recorded by Hermann Claasen from 1942 until the end of the war, and presented in his exhibition and book of 1947 ''Singing in the furnace.", "Cologne – Remains of an old city''.Cologne was taken by the American First Army in early March 1945 during the Invasion of Germany after a battle.", "By the end of the war, the population of Cologne had been reduced by 95%.", "This loss was mainly caused by a massive evacuation of the people to more rural areas.", "The same happened in many other German cities in the last two years of war.", "By the end of 1945, however, the population had already recovered to approximately 450,000.By the end of the war, essentially all of Cologne's pre-war Jewish population of 11,000 had been deported or killed by the Nazis.", "The six synagogues of the city were destroyed.", "The synagogue on Roonstraße was rebuilt in 1959.===Post-war and Cold War eras===Cologne, seen from ESA Sentinel-2Despite Cologne's status as the largest city in the region, nearby Düsseldorf was chosen as the political capital of the federated state of North Rhine-Westphalia.", "With Bonn being chosen as the provisional federal capital (''provisorische Bundeshauptstadt'') and seat of the government of the Federal Republic of Germany (then informally West Germany), Cologne benefited by being sandwiched between two important political centres.", "The city became–and still is–home to a number of federal agencies and organizations.", "After reunification in 1990, Berlin was made the capital of Germany.In 1945 architect and urban planner Rudolf Schwarz called Cologne the \"world's greatest heap of rubble\".", "Schwarz designed the master plan for reconstruction in 1947, which included the construction of several new thoroughfares through the city centre, especially the ''Nord-Süd-Fahrt'' (\"North-South-Drive\").", "The master plan took into consideration the fact that even shortly after the war a large increase in automobile traffic could be anticipated.", "Plans for new roads had already, to a certain degree, evolved under the Nazi administration, but the actual construction became easier when most of the city centre was in ruins.The destruction of 95% of the city centre, including the famous Twelve Romanesque churches such as St. Gereon, Great St. Martin, St. Maria im Kapitol and several other monuments in World War II, meant a tremendous loss of cultural treasures.", "The rebuilding of those churches and other landmarks such as the Gürzenich event hall was not undisputed among leading architects and art historians at that time, but in most cases, civil intention prevailed.", "The reconstruction lasted until the 1990s, when the Romanesque church of St. Kunibert was finished.In 1959, the city's population reached pre-war numbers again.", "It then grew steadily, exceeding 1 million for about one year from 1975.It remained just below that until mid-2010, when it exceeded 1 million again.Cologne in 2013===Post-reunification===Soviet letter's envelope in honor of the Internationale Philatelic Exhibition ''LUPOSTA'' in Cologne in 1983In the 1980s and 1990s Cologne's economy prospered for two main reasons.", "The first was the growth in the number of media companies, both in the private and public sectors; they are especially catered for in the newly developed Media Park, which creates a strong visual focal point in Cologne's city centre and includes the ''KölnTurm'', one of Cologne's most prominent high-rise buildings.", "The second was the permanent improvement of the diverse traffic infrastructure, which made Cologne one of the most easily accessible metropolitan areas in Central Europe.Due to the economic success of the Cologne Trade Fair, the city arranged a large extension to the fair site in 2005.At the same time the original buildings, which date back to the 1920s, were rented out to RTL, Germany's largest private broadcaster, as their new corporate headquarters.Cologne was the focus of the 2015-16 New Year's Eve sexual assaults in Germany, with over 500 women reporting that they were sexually assaulted by persons of African and Arab appearance." ], [ "Geography", "The metropolitan area encompasses over , extending around a central point that lies at 50° 56' 33 latitude and 6° 57' 32 longitude.", "The city's highest point is above sea level (the Monte Troodelöh) and its lowest point is above sea level (the Worringer Bruch).", "The city of Cologne lies within the larger area of the Cologne Lowland, a cone-shaped area of the central Rhineland that lies between Bonn, Aachen and Düsseldorf.===Districts===Cologne is divided into 9 boroughs (''Stadtbezirke'') and 85 districts (''Stadtteile''):; Innenstadt (Stadtbezirk 1): Altstadt-Nord, Altstadt-Süd, Neustadt-Nord, Neustadt-Süd, Deutz; Rodenkirchen (Stadtbezirk 2): Bayenthal, Godorf, Hahnwald, Immendorf, Marienburg, Meschenich, Raderberg, Raderthal, Rodenkirchen, Rondorf, Sürth, Weiß, Zollstock; Lindenthal (Stadtbezirk 3): Braunsfeld, Junkersdorf, Klettenberg, Lindenthal, Lövenich, Müngersdorf, Sülz, Weiden, Widdersdorf; Ehrenfeld (Stadtbezirk 4): Bickendorf, Bocklemünd/Mengenich, Ehrenfeld, Neuehrenfeld, Ossendorf, Vogelsang; Nippes (Stadtbezirk 5): Bilderstöckchen, Longerich, Mauenheim, Niehl, Nippes, Riehl, Weidenpesch 300px; Chorweiler (Stadtbezirk 6): Blumenberg, Chorweiler, Esch/Auweiler, Fühlingen, Heimersdorf, Lindweiler, Merkenich, Pesch, Roggendorf/Thenhoven, Seeberg, Volkhoven/Weiler, Worringen; Porz (Stadtbezirk 7): Eil, Elsdorf, Ensen, Finkenberg, Gremberghoven, Grengel, Langel, Libur, Lind, Poll, Porz, Urbach, Wahn, Wahnheide, Westhoven, Zündorf; Kalk (Stadtbezirk 8): Brück, Höhenberg, Humboldt/Gremberg, Kalk, Merheim, Neubrück, Ostheim, Rath/Heumar, Vingst; Mülheim (Stadtbezirk 9): Buchforst, Buchheim, Dellbrück, Dünnwald, Flittard, Höhenhaus, Holweide, Mülheim, Stammheim===Climate===Located in the Rhine-Ruhr area, Cologne is one of the warmest cities in Germany.", "It has a temperate–oceanic climate (Köppen: ''Cfb'') with cool winters and warm summers.", "It is also one of the cloudiest cities in Germany, with just 1,567.5 hours of sun a year.", "Its average annual temperature is : during the day and at night.", "In January, the mean temperature is , while the mean temperature in July is .", "The record high temperature of happened on 25 July 2019 during the July 2019 European heat wave in which Cologne saw three consecutive days over .", "Especially the inner urban neighbourhoods experience a greater number of hot days, as well as significantly higher temperatures during nighttime compared to the surrounding area (including the airport, where temperatures are classified).", "Still temperatures can vary noticeably over the course of a month with warmer and colder weather.", "Precipitation is spread evenly throughout the year with a light peak in summer due to showers and thunderstorms.===Flood protection===The 1930 flood in CologneCologne is regularly affected by flooding from the Rhine and is considered the most flood-prone European city.", "A city agency (''Stadtentwässerungsbetriebe Köln'', \"Cologne Urban Drainage Operations\") manages an extensive flood control system which includes both permanent and mobile flood walls, protection from rising waters for buildings close to the river banks, monitoring and forecasting systems, pumping stations and programmes to create or protect floodplains, and river embankments.", "The system was redesigned after a 1993 flood, which resulted in heavy damage." ], [ "Demographics", "'''Largest groups of foreign residents''' Population (2022) 57,135 21,351 12,634 9,766 8,631 8,074 7,916 5,841 4,910 4,837 4,786 4,651 3,954 3,830 3,539 3,263 3,043 2,586 2,523 2,418 2,394 2,328 2,287In the Roman Empire, the city was large and rich with a population of 40,000 in 100–200 AD.", "The city was home to around 20,000 people in 1000 AD, growing to 50,000 in 1200 AD.", "The Rhineland metropolis still had 50,000 residents in 1300 AD.Cologne is the fourth-largest city in Germany after Berlin, Hamburg and Munich.", "As of 31 December 2021, there were 1,079,301 people registered as living in Cologne in an area of , which makes Cologne the third largest city by area.", "The population density was .", "Cologne first reached the population of 1,000,000 in 1975 due to the incorporation of Wesseling, however this was reversed after public opposition.", "In 2009 Cologne's population again reached 1,000,000 and it became one of the four cities in Germany with a population exceeding 1 Million.", "The metropolitan area of the Cologne Bonn Region is home to 3,573,500 living on .", "It is part of the polycentric megacity region Rhine-Ruhr with a population of over 11,000,000 people.There were 551,528 women and 527,773 men in Cologne.", "In 2021, there were 11,127 births in Cologne; 5,844 marriages and 1,808 divorces, and 10,536 deaths.", "In the city, the population was spread out, with 16.3% under the age of 18, and 17.8% were 65 years of age or older.", "203 people in Cologne were over the age of 100.According to the Statistical Office of the City of Cologne, the number of people with a migrant background is at 40.5% (436,660).", "2,254 people acquired German citizenship in 2021.In 2021, there were 559,854 households, of which 18.4% had children under the age of 18; 51% of all households were made up of singles.", "8% of all households were single-parent households.", "The average household size was 1.88.===Residents with foreign citizenship===Cologne residents with a foreign citizenship as of 31 December 2021 is as follows:CitizenshipNumber% Total436,660100%Europe283,96065%European Union138,96131.8%Asian78,23517.9%African29,5526.8%American13,7863.2%Australian and Oceanian6660.2%===Turkish community===Cologne is home to 90,000 people of Turkish origin and is the second largest German city with Turkish population after Berlin.", "Cologne has a Little Istanbul in Keupstraße that has many Turkish restaurants and markets.", "Famous Turkish-German people like rapper Eko Fresh and TV presenter Nazan Eckes were born in Cologne.===Language==='''Colognian''' or '''Kölsch''' () (natively ''Kölsch Platt'') is a small set of very closely related dialects, or variants, of the Ripuarian Central German group of languages.", "These dialects are spoken in the area covered by the Archdiocese and former Electorate of Cologne reaching from Neuss in the north to just south of Bonn, west to Düren and east to Olpe in the North-West of Germany.", "Kölsch is one of the very few city dialects in Germany, which also include the dialect spoken in Berlin, for example.===Religion===As of 2015, 35.5% of the population belonged to the Catholic Church, the largest religious body, and 15.5% to the Protestant Church.", "Irenaeus of Lyons claimed that Christianity was brought to Cologne by Roman soldiers and traders at an unknown early date.", "It is known that in the early second century it was a bishop's seat.", "The first historical Bishop of Cologne was Saint Maternus.", "Thomas Aquinas studied in Cologne in 1244 under Albertus Magnus.", "Cologne is the seat of the Archdiocese of Cologne.According to the 2011 census, 2.1% of the population was Eastern Orthodox, 0.5% belonged of an Evangelical Free Church and 4.2% belonged to further religious communities officially recognized by the state of North Rhine-Westphalia (such as Jehovah's Witnesses).There are several mosques, including the Cologne Central Mosque run by the Turkish-Islamic Union for Religious Affairs.", "In 2011, about 11.2% of the population was Muslim.Cologne also has one of the oldest and largest Jewish communities in Germany.", "In 2011, 0.3% of Cologne's population was Jewish.On 11 October 2021, the Mayor of Cologne, Henriette Reker, announced that all of Cologne's 35 mosques would be allowed to broadcast the Adhan (prayer call) for up to five minutes on Fridays between noon and 3 p.m. She commented that the move \"shows that diversity is appreciated and loved in Cologne\"." ], [ "Government and politics", "The city's administration is headed by the mayor and the three deputy mayors.===Political traditions and developments===The long tradition of a free imperial city, which long dominated an exclusively Catholic population and the age-old conflict between the church and the bourgeoisie (and within it between the patricians and craftsmen) have created its own political climate in Cologne.", "Various interest groups often form networks beyond party boundaries.", "The resulting web of relationships, with political, economic, and cultural links with each other in a system of mutual favours, obligations and dependencies, is called the 'Cologne coterie'.", "This has often led to an unusual proportional distribution in the city government and degenerated at times into corruption: in 1999, a \"waste scandal\" over kickbacks and illegal campaign contributions came to light, which led not only to the imprisonment of the entrepreneur Hellmut Trienekens, but also to the downfall of almost the entire leadership of the ruling Social Democrats.===Mayor===Results of the second round of the 2020 mayoral electionThe current Lord Mayor of Cologne is Henriette Reker.", "She received 52.66% of the vote at the municipal election on 17 October 2015, running as an independent with the support of the CDU, FDP, and Greens.", "She took office on 15 December 2015.Reker was re-elected to a second term in a runoff election on 27 September 2020, in which she received 59.27% of the vote.The most recent mayoral election was held on 13 September 2020, with a runoff held on 27 September, and the results were as follows: Candidate Party First round Second round Votes % Votes % Henriette Reker Independent (Green/CDU) 187,389 45.1 174,263 59.3 Andreas Kossiski Social Democratic Party 111,353 26.8 119,753 40.7 Jörg Detjen The Left 29,810 7.2 Olivier Fuchs Volt Germany 18,520 4.5 Christer Cremer Alternative for Germany 17,441 4.2 Nicolin Gabrysch Climate Friends 14,370 3.5 Roberto Campione Independent 14,122 3.4 Thor Zimmermann Good Cologne 8,613 2.1 Dagmar Langel We Are Cologne 4,464 1.1 Robert Nussholz Independent 4,044 1.0 Sabine Neumeyer Independent 2,547 0.6 Rüdiger-René Keune Ecological Democratic Party 2,336 0.6 Martin Przybylski Independent 924 0.2 Valid votes 415,933 98.7 294,016 99.1 Invalid votes 5,633 1.3 2,727 0.9 Total 421,566 100.0 296,743 100.0 Electorate/voter turnout 820,527 51.4 818,731 36.2 Source: City of Cologne ( 1st round, 2nd round)===City council===Results of the 2020 city council electionThe Cologne city council (''Kölner Stadtrat'') governs the city alongside the Mayor.", "It serves a term of five years.", "The most recent city council election was held on 13 September 2020, and the results were as follows: Party Votes % +/- Seats +/- Alliance 90/The Greens (Grüne) 118,997 28.5 9.0 26 8 Social Democratic Party (SPD) 90,040 21.6 7.8 19 7 Christian Democratic Union (CDU) 89,659 21.5 5.7 19 6 The Left (Die Linke) 27,044 6.5 0.4 6 ±0 Free Democratic Party (FDP) 21,965 5.3 0.2 5 ±0 Volt Germany (Volt) 20,783 5.0 New 4 New Alternative for Germany (AfD) 18,272 4.4 0.8 4 1 Die PARTEI (PARTEI) 10,261 2.5 2.4 2 2 Climate Friends (Klima Freunde) 8,383 2.0 0.0 2 ±0 Good Cologne (GUT) 8,298 2.0 0.6 2 ±0 Free Voters Cologne (FWK) 2,501 0.6 0.2 1 ±0 Ecological Democratic Party (ÖDP) 374 0.1 New 0 New We Are Cologne 2020 (Wir Sind Köln) 265 0.1 New 0 New Independent A. Krause 107 0.0 New 0 New Independent Neumeyer 72 0.0 New 0 New Independent Weber 72 0.0 New 0 New Independent R. Krause 71 0.0 New 0 New Independent Schidlowsky 32 0.0 New 0 New Party of Progress (PdF) 31 0.0 New 0 New Valid votes 417,227 98.9 Invalid votes 4,596 1.1 Total 421,823 100.0 90 ±0 Electorate/voter turnout 820,526 51.4 1.8 Source: City of Cologne===State Landtag===2022 state election in CologneIn the Landtag of North Rhine-Westphalia, Cologne is divided between seven constituencies.", "After the 2022 North Rhine-Westphalia state election, the composition and representation of each was as follows: Constituency Area Party Member 13 Köln I Rodenkirchen and part of Innenstadt Grüne Eileen Woestmann 14 Köln II Lindenthal Grüne Frank Jablonski 15 Köln III Ehrenfeld and part of Nippes Grüne Arndt Klocke 16 Köln IV Chorweiler and most of Nippes SPD Lena Teschlade 17 Köln V Porz and the east of Kalk CDU Florian Braun 18 Köln VI Most of Innenstadt and the west of Kalk Grüne Berivan Aymaz 19 Köln VII Mülheim SPD Carolin Kirsch=== Federal parliament ===In the Bundestag, Cologne is divided between four constituencies.", "In the 20th Bundestag, the composition and representation of each was as follows: Constituency Area Party Member 93 Cologne I Porz, Kalk, and part of Innenstadt SPD Sanae Abdi 94 Cologne II Rodenkirchen, Lindenthal, and part of Innenstadt Grüne Sven Lehmann 95 Cologne III Ehrenfeld, Nippes, and Chorweiler SPD Rolf Mützenich 101 Leverkusen – Cologne IV Mülheim (and the city of Leverkusen) SPD Karl Lauterbach" ], [ "Cityscape", "The inner city of Cologne was largely destroyed during World War II.", "The reconstruction of the city followed the style of the 1950s, while respecting the old layout and naming of the streets.", "Thus, the city centre today is characterized by modern architecture, with a few interspersed pre-war buildings which were reconstructed due to their historical importance.", "Some buildings of the \"Wiederaufbauzeit\" (era of reconstruction), for example, the opera house by Wilhelm Riphahn, are nowadays regarded as classics of modern architecture.", "Nevertheless, the uncompromising style of the Cologne Opera house and other modern buildings has remained controversial.Green areas account for over a quarter of Cologne, which is approximately of public green space for every inhabitant." ], [ "Wildlife", "The dominant wildlife of Cologne is insects, small rodents, and several species of birds.", "Pigeons are the most often seen animals in Cologne, although the number of birds is augmented each year by a growing population of feral exotics, most visibly parrots such as the rose-ringed parakeet.", "The sheltered climate in southeast Northrhine-Westphalia allows these birds to survive through the winter, and in some cases, they are displacing native species.", "The plumage of Cologne's green parrots is highly visible even from a distance, and contrasts starkly with the otherwise muted colours of the cityscape.Hedgehogs, rabbits and squirrels are common in parks and the greener parts of town.", "In the outer suburbs foxes and wild boar can be seen, even during the day." ], [ "Tourism", "Cologne had 5.8 million overnight stays booked and 3.35 million arrivals in 2016.Köln Cathedral on the banks of Rhine===Landmarks=======Churches====* Cologne Cathedral (German: ''Kölner Dom'') is the city's most famous monument and the Cologne residents' most loved landmark.", "It is a Gothic church, started in 1248, and completed in 1880.In 1996, it was designated a World Heritage Site; it houses the Shrine of the Three Kings, which supposedly contains the relics of the Three Magi (see also).", "Residents of Cologne sometimes refer to the cathedral as \"the eternal construction site\" (''die ewige Baustelle'').", "* Twelve Romanesque churches: These buildings are outstanding examples of medieval church architecture.", "The origins of some of the churches go back as far as Roman times, for example St. Gereon, which was originally a chapel in a Roman graveyard.", "With the exception of St. Maria Lyskirchen all of these churches were very badly damaged during World War II.", "Reconstruction was only finished in the 1990s.Kdom.jpg|Cologne CathedralKöln - Groß St. Martin vom Dom.jpg|Great St. Martin ChurchSevereinskirche aus Severinstorburg 2009.jpg|Basilica of St. SeverinKoeln mariae himmelfahrt 001.jpg|Church of the AssumptionTrinitatiskirche Koeln2007.jpg|Trinity Church====Medieval houses====The Cologne City Hall (''Kölner Rathaus''), founded in the 12th century, is the oldest city hall in Germany still in use.", "The Renaissance-style loggia and tower were added in the 15th century.", "Other famous buildings include the Gürzenich, Haus Saaleck and the Overstolzenhaus.File:Keoln Maerz 2009 PD 20090327 028.JPG|Cologne City HallFile:Köln gürzenich.jpg|GürzenichFile:Overstolzenhaus-Rheingasse-Köln.JPG|Overstolzenhaus====Medieval city gates==== A plan published in 1800 shows the medieval city wall still intact, locating 16 gates (Nr.", "36–51 in the legend), e.g., 47: Eigelsteintor, 43: Hahnentor, 39: Severinstor.Of the twelve medieval city gates that once existed, only the Eigelsteintorburg at Ebertplatz, the Hahnentor at Rudolfplatz and the Severinstorburg at Chlodwigplatz still stand today.File:Köln eigelsteintorburg.jpg|EigelsteintorFile:Hahnentorburg.jpg|HahnentorFile:Severinstorburg Köln-0410.jpg|Severinstor===Streets===* The Cologne Ring boulevards (such as ''Hohenzollernring'', ''Kaiser-Wilhelm-Ring'', ''Hansaring'') with their medieval city gates (such as ''Hahnentorburg'' on ''Rudolfplatz'') are also known for their night life.", "* Hohe Straße (literally: ''High Street'') is one of the main shopping areas and extends past the cathedral in an approximately southerly direction.", "The street contains many gift shops, clothing stores, fast food restaurants and electronic goods dealers.", "* Schildergasse – connects ''Neumarkt'' square at its western end to the ''Hohe Strasse'' shopping street at its eastern end and has been named the busiest shopping street in Europe with 13,000 people passing through every hour, according to a 2008 study by GfK.", "* Ehrenstraße – the shopping area around ''Apostelnstrasse'', ''Ehrenstrasse'', and ''Rudolfplatz'' is a little more on the quirky and stylish side.===Bridges===Bridge in Cologne over the Rhine River Rhine River at CologneSeveral bridges cross the Rhine in Cologne.", "They are (from south to north): the Cologne Rodenkirchen Bridge, South Bridge (railway), Severin Bridge, Deutz Bridge, Hohenzollern Bridge (railway), Zoo Bridge (''Zoobrücke'') and Cologne Mülheim Bridge.", "In particular the iron tied arch Hohenzollern Bridge (''Hohenzollernbrücke'') is a dominant landmark along the river embankment.", "A Rhine crossing of a special kind is provided by the Cologne Cable Car (German: ''Kölner Seilbahn''), a cableway that runs across the Rhine between the Cologne Zoological Garden in Riehl and the Rheinpark in Deutz.===High-rise structures===Cologne's tallest structure is the Colonius telecommunication tower at .", "The observation deck has been closed since 1992.A selection of the tallest buildings in Cologne is listed below.", "Other tall structures include the Hansahochhaus (designed by architect Jacob Koerfer and completed in 1925 – it was at one time Europe's tallest office building), the Kranhaus buildings at Rheinauhafen, and the Messeturm Köln (\"trade fair tower\").", "Skyscraper Image Height in metres Floors Year Address Notes KölnTurm 60px 148.5 43 2001 MediaPark 8, Neustadt-Nord (literally: ''Cologne Tower''), Cologne's second tallest building at in height, second only to the Colonius telecommunication tower.", "The 30th floor of the building has a restaurant and a terrace with 360° views of the city.", "Colonia-Hochhaus 60px 147 45 1973 An der Schanz 2, Riehl tallest building in Germany from 1973 to 1976.Today, it is still the country's second tallest residential building.Rheintower 60px 138 34 1980 Raderberggürtel, Marienburg former headquarters of Deutsche Welle, since 2007 under renovation with the new name ''Rheintower Köln-Marienburg''.", "Uni-Center 60px 133 45 1973 Luxemburger Straße, Sülz TÜV Rheinland 60px 112 22 1974 Am Grauen Stein, Poll Ringturm 60px 109 26 1973 Ebertplatz, Neustadt-Nord Justizzentrum Köln 60px 105 25 1981 Luxemburger Straße, Sülz KölnTriangle 60px 103 29 2006 Ottoplatz 1, Deutz opposite to the cathedral with a high viewing platform and a view of the cathedral over the Rhine.", "Herkules-Hochhaus 60px 102 31 1969 Graeffstraße 1, Ehrenfeld Deutschlandfunk-Turm 60px 102 19 1975 Raderberggürtel, Marienburg" ], [ "Culture", "Courtyard of the Kolumba museum in 2007, designed by Peter Zumthor''Tauzieher'', a limestone sculpture by Nikolaus Friedrich, 1911Cologne has several museums.", "The famous Roman-Germanic Museum features art and architecture from the city's distant past; the Museum Ludwig houses one of the most important collections of modern art in Europe, including a Picasso collection matched only by the museums in Barcelona and Paris.", "The Museum Schnütgen of religious art is partly housed in St. Cecilia, one of Cologne's Twelve Romanesque churches.", "Many art galleries in Cologne enjoy a worldwide reputation like e.g.", "Galerie Karsten Greve, one of the leading galleries for postwar and contemporary art.Cologne has more than 60 music venues and the third-highest density of music venues of Germany's four largest cities, after Munich and Hamburg and ahead of Berlin.Several orchestras are active in the city, among them the Gürzenich Orchestra, which is also the orchestra of the Cologne Opera and the WDR Symphony Orchestra Cologne (''German State Radio Orchestra''), both based at the Cologne Philharmonic Orchestra Building (Kölner Philharmonie).", "Other orchestras are the Musica Antiqua Köln, the WDR Rundfunkorchester Köln and WDR Big Band, and several choirs, including the WDR Rundfunkchor Köln.", "Cologne was also an important hotbed for electronic music in the 1950s (Studio für elektronische Musik, Karlheinz Stockhausen) and again from the 1990s onward.", "The public radio and TV station WDR was involved in promoting musical movements such as Krautrock in the 1970s; the influential Can was formed there in 1968.There are several centres of nightlife, among them the ''Kwartier Latäng'' (the student quarter around the Zülpicher Straße) and the nightclub-studded areas around Hohenzollernring, Friesenplatz and Rudolfplatz.Water feature in Cologne, summer 2017The large annual literary festival with its features regional and international authors.", "The main literary figure connected with Cologne is the writer Heinrich Böll, winner of the Nobel Prize for Literature.", "Since 2012, there is also an annual international festival of philosophy called .The city also has the most pubs per capita in Germany.", "Cologne is well known for its beer, called Kölsch.", "Kölsch is also the name of the local dialect.", "This has led to the common joke of Kölsch being the only language one can drink.Cologne is also famous for Eau de Cologne (German: ''Kölnisch Wasser''; lit: \"Water of Cologne\"), a perfume created by Italian expatriate Johann Maria Farina at the beginning of the 18th century.", "During the 18th century, this perfume became increasingly popular, was exported all over Europe by the Farina family and ''Farina'' became a household name for ''Eau de Cologne''.", "In 1803 Wilhelm Mülhens entered into a contract with an unrelated person from Italy named Carlo Francesco Farina who granted him the right to use his family name and Mühlens opened a small factory at Cologne's Glockengasse.", "In later years, and after various court battles, his grandson Ferdinand Mülhens was forced to abandon the name ''Farina'' for the company and their product.", "He decided to use the house number given to the factory at Glockengasse during the French occupation in the early 19th century, 4711.Today, original Eau de Cologne is still produced in Cologne by both the Farina family, currently in the eighth generation, and by Mäurer & Wirtz who bought the 4711 brand in 2006.===Carnival===The Cologne carnival is one of the largest street festivals in Europe.", "In Cologne, the carnival season officially starts on 11 November at 11 minutes past 11 a.m. with the proclamation of the new Carnival Season, and continues until Ash Wednesday.", "However, the so-called \"Tolle Tage\" (crazy days) do not start until ''Weiberfastnacht'' (Women's Carnival) or, in dialect, ''Wieverfastelovend'', the Thursday before Ash Wednesday, which is the beginning of the street carnival.", "Zülpicher Strasse and its surroundings, Neumarkt square, Heumarkt and all bars and pubs in the city are crowded with people in costumes dancing and drinking in the streets.", "Hundreds of thousands of visitors flock to Cologne during this time.", "Generally, around a million people celebrate in the streets on the Thursday before Ash Wednesday.===Rivalry with Düsseldorf===Cologne and Düsseldorf have a \"fierce regional rivalry\", which includes carnival parades, football, and beer.", "People in Cologne prefer Kölsch while people in Düsseldorf prefer Altbier (\"Alt\").", "Waiters and patrons will \"scorn\" and make a \"mockery\" of people who order Alt beer in Cologne or Kölsch in Düsseldorf.", "The rivalry has been described as a \"love–hate relationship\".", "The Köln Guild of Brewers was established in 1396.The Kölsch beer style first appeared in the 1800s and in 1986 the breweries established an appellation under which only breweries in the city are allowed to use the term Kölsch.===Museums===The Museum Ludwig houses one of the most important collections of modern art.excavation in Cologne: Dionysus Mosaic on display at Römisch-Germanisches Museum* Farina Fragrance Museum – birthplace of Eau de Cologne* Römisch-Germanisches Museum (Roman-Germanic Museum) – ancient Roman and Germanic culture* Wallraf-Richartz Museum – European painting from the 13th to the early 20th century* Museum Ludwig – modern art* Museum Schnütgen – medieval art* Museum für Angewandte Kunst – applied art* Kolumba Kunstmuseum des Erzbistums Köln (art museum of the Archbishopric of Cologne) – modern art museum built around medieval ruins of St. Kolumba, Cologne, completed 2007* Cathedral Treasury \"Domschatzkammer\" – historic underground vaults of the Cathedral* EL-DE Haus – former local headquarters of the Gestapo houses a museum documenting Nazi rule in Cologne with a special focus on the persecution of political dissenters and minorities* German Sports and Olympic Museum – exhibitions about sports from antiquity until the present* Imhoff-Schokoladenmuseum – Chocolate Museum* Geomuseum of the University of Cologne – the exhibition includes fossils (such as dinosaur bones and the skeleton of an Eryops), stones and minerals* Forum for Internet Technology in Contemporary Art – collections of Internet-based art, corporate part of (NewMediaArtProjectNetwork):cologne, the experimental platform for art and New Media* Flora und Botanischer Garten Köln – the city's formal park and main botanical garden* Forstbotanischer Garten Köln – an arboretum and woodland botanical garden===Music fairs and festivals===The city was home to the internationally famous Ringfest, and now to the C/o pop festival.In addition, Cologne enjoys a thriving Christmas Market (''Weihnachtsmarkt'') presence with several locations in the city." ], [ "Economy", "North entrance to Koelnmesse, 2008Modern office building at Rheinauhafen, EA Games headquartersAs the largest city in the Rhine-Ruhr metropolitan region, Cologne benefits from a large market structure.", "In competition with Düsseldorf, the economy of Cologne is primarily based on insurance and media industries, while the city is also an important cultural and research centre and home to a number of corporate headquarters.Among the largest media companies based in Cologne are Westdeutscher Rundfunk, RTL Television (with subsidiaries), n-tv, Deutschlandradio, Brainpool TV and publishing houses like J. P. Bachem, Taschen, Tandem Verlag, and M. DuMont Schauberg.", "Several clusters of media, arts and communications agencies, TV production studios, and state agencies work partly with private and government-funded cultural institutions.", "Among the insurance companies based in Cologne are Central, DEVK, DKV, Generali Deutschland, Gen Re, Gothaer, HDI Gerling and national headquarters of Axa Insurance, Mitsui Sumitomo Insurance Group and Zurich Financial Services.The German flag carrier Lufthansa and its subsidiary Lufthansa CityLine have their main corporate headquarters in Cologne.", "The largest employer in Cologne is Ford Europe, which has its European headquarters and a factory in Niehl (Ford-Werke GmbH).", "Toyota Motorsport GmbH (TMG), Toyota's official motorsports team, responsible for Toyota rally cars, and then Formula One cars, has its headquarters and workshops in Cologne.", "Other large companies based in Cologne include the REWE Group, TÜV Rheinland, Deutz AG and a number of Kölsch breweries.", "The largest three Kölsch breweries of Cologne are Reissdorf, Gaffel, and Früh.", "Brewery Established Annual output ''in hectoliters'' Heinrich Reissdorf 1894 650,000 Gaffel Becker & Co 1908 500,000 Cölner Hofbräu Früh 1904 440,000Historically, Cologne has always been an important trade city, with land, air, and sea connections.", "The city has five Rhine ports, the second largest inland port in Germany and one of the largest in Europe.", "Cologne Bonn Airport is the second largest freight terminal in Germany.", "Today, the Cologne trade fair (''Koelnmesse'') ranks as a major European trade fair location with over 50 trade fairs and other large cultural and sports events.", "In 2008 Cologne had 4.31 million overnight stays booked and 2.38 million arrivals.", "Cologne's largest daily newspaper is the ''Kölner Stadt-Anzeiger''.Cologne shows a significant increase in startup companies, especially when considering digital business.Cologne has also become the first German city with a population of more than a million people to declare climate emergency." ], [ "Transport", "===Road transport===roads through and around CologneRoad building had been a major issue in the 1920s under the leadership of mayor Konrad Adenauer.", "The first German limited-access road was constructed after 1929 between Cologne and Bonn.", "Today, this is the Bundesautobahn 555.In 1965, Cologne became the first German city to be fully encircled by a motorway ring road.", "Roughly at the same time, a city centre bypass (''Stadtautobahn'') was planned, but only partially put into effect, due to opposition by environmental groups.", "The completed section became ''Bundesstraße (\"Federal Road\") B 55a'', which begins at the ''Zoobrücke'' (\"Zoo Bridge\") and meets with A 4 and A 3 at the interchange Cologne East.", "Nevertheless, it is referred to as ''Stadtautobahn'' by most locals.", "In contrast to this, the ''Nord-Süd-Fahrt'' (\"North-South-Drive\") was actually completed, a new four/six-lane city centre through-route, which had already been anticipated by planners such as Fritz Schumacher in the 1920s.", "The last section south of ''Ebertplatz'' was completed in 1972.In 2005, the first stretch of an eight-lane motorway in North Rhine-Westphalia was opened to traffic on Bundesautobahn 3, part of the eastern section of the Cologne Beltway between the interchanges Cologne East and Heumar.===Cycling===Bensberg stationTrain at Köln HauptbahnhofCompared to other German cities, Cologne has a traffic layout that is not very bicycle-friendly.", "It has repeatedly ranked among the worst in an independent evaluation conducted by the Allgemeiner Deutscher Fahrrad-Club.", "In 2014, it ranked 36th out of 39 German cities with a population greater than 200,000.===Rail transport===Cologne has a railway service with InterCity and ICE-trains stopping at Köln Hauptbahnhof (Cologne Main Station), Köln Messe/Deutz and Cologne/Bonn Airport.", "ICE and TGV Thalys high-speed trains link Cologne with Amsterdam, Brussels (in 1h47, 9 departures/day) and Paris (in 3h14, 6 departures/day).", "There are frequent ICE trains to other German cities, including Frankfurt am Main and Berlin.", "ICE Trains to London via the Channel Tunnel were planned for 2013.The Cologne Stadtbahn operated by Kölner Verkehrsbetriebe (KVB) is an extensive light rail system that is partially underground and serves Cologne and a number of neighbouring cities.", "It evolved from the tram system.", "Nearby Bonn is linked by both the Stadtbahn and main line railway trains, and occasional recreational boats on the Rhine.", "Düsseldorf is also linked by S-Bahn trains, which are operated by .The Rhine-Ruhr S-Bahn has 5 lines which cross Cologne.", "The S13/S19 runs 24/7 between Cologne Hbf and Cologne/Bonn airport.There are also frequent buses covering most of the city and surrounding suburbs, and Eurolines coaches to London via Brussels.===Water transport===Häfen und Güterverkehr Köln (Ports and Goods traffic Cologne, HGK) is one of the largest operators of inland ports in Germany.", "Ports include Köln-Deutz, Köln-Godorf, and Köln-Niehl I and II.===Air transport===Cologne's international airport is Cologne/Bonn Airport (CGN).", "It is also called Konrad Adenauer Airport after Germany's first post-war Chancellor Konrad Adenauer, who was born in the city and was mayor of Cologne from 1917 until 1933.The airport is shared with the neighbouring city of Bonn.", "Cologne is headquarters to the European Aviation Safety Agency (EASA)." ], [ "Education", "Cologne is home to numerous universities and colleges, and host to some 72,000 students.", "Its oldest university, the University of Cologne (founded in 1388) is the largest university in Germany, as the Cologne University of Applied Sciences is the largest university of Applied Sciences in the country.", "The Cologne University of Music and Dance is the largest conservatory in Europe.", "Foreigners can have German lessons in the VHS (Adult Education Centre).", "* Public and state universities:** University of Cologne (''Universität zu Köln'');** German Sport University Cologne (''Deutsche Sporthochschule Köln'').", "* Public and state colleges:** Cologne University of Applied Sciences (''\"Technology, Arts, Sciences TH KöLN\" Technische Hochschule Köln'');** Köln International School of Design;** Cologne University of Music and Dance ();** Academy of Media Arts Cologne (''Kunsthochschule für Medien Köln'');* Private colleges:** Catholic University of Applied Sciences (''Katholische Hochschule Nordrhein-Westfalen'');** Cologne Business School;** international filmschool cologne (''internationale filmschule köln'');** Rhenish University of Applied Sciences (''Rheinische Fachhochschule Köln'')** University of Applied Sciences Fresenius (''Hochschule Fresenius'')* Research institutes:** German Aerospace Centre (''Deutsches Zentrum für Luft- und Raumfahrt'');** European Astronaut Centre (''EAC'') of the European Space Agency;** European College of Sport Science (''ECSS'');** Max Planck Institute for the Biology of Ageing (''Max-Planck-Institut für die Biologie des Alterns'');** Max Planck Institute for the Study of Societies (''Max-Planck-Institut für Gesellschaftsforschung'');** Max Planck Institute for Neurological Research (''Max-Planck-Institut für neurologische Forschung'');** Max Planck Institute for Plant Breeding Research (''Max-Planck-Institut für Züchtungsforschung'').", "** CologneAMS – Centre for Accelerator Mass Spectrometry, Institute for Nuclear Physics, University of CologneFormer colleges include:* The Cologne Art and Crafts Schools (''Kölner Werkschulen'');* The Cologne Institute for Religious Art (''Kölner Institut für religiöse Kunst'')Lauder Morijah School (), a Jewish school in Cologne, previously closed.", "After Russian immigration increased the Jewish population, the school reopened in 2002." ], [ "Media", "Within Germany, Cologne is known as an important media centre.", "Several radio and television stations, including Westdeutscher Rundfunk (WDR), RTL and VOX, have their headquarters in the city.", "Film and TV production is also important.", "The city is \"Germany's capital of TV crime stories\".", "A third of all German TV productions are made in the Cologne region.", "Furthermore, the city hosts the Cologne Comedy Festival, which is considered to be the largest comedy festival in mainland Europe." ], [ "Sports", "RheinEnergieStadion is the stadium of 1.Bundesliga club 1.FC Köln.Cologne hosts the football club 1.FC Köln, who play in the 1.Bundesliga (first division).", "They play their home matches in RheinEnergieStadion which also hosted five matches of the 2006 FIFA World Cup.", "The International Olympic Committee and the International Association of Sports and Leisure Facilities gave RheinEnergieStadion a bronze medal for \"being one of the best sporting venues in the world\".", "The city also hosts the two football clubs FC Viktoria Köln and SC Fortuna Köln, who currently play in the 3.Liga (third division) and the Regionalliga West (fourth division) respectively.", "Cologne's oldest football club 1.FSV Köln 1899 is playing with its amateur team in the Verbandsliga (sixth division).Cologne also is home of the ice hockey team Kölner Haie, which is playing in the highest ice hockey league in Germany, the Deutsche Eishockey Liga.", "They are based at Lanxess Arena.Several horse races per year are held at Cologne-Weidenpesch Racecourse since 1897, the annual Cologne Marathon was started in 1997 and the classic cycling race Rund um Köln is organised in Cologne since 1908.The city also has a long tradition in rowing, being home of some of Germany's oldest regatta courses and boat clubs, such as the Kölner Rudergesellschaft 1891 or the Kölner Ruderverein von 1877 in the Rodenkirchen district.Japanese automotive manufacturer Toyota has their major motorsport facility known by the name Toyota Motorsport GmbH, which is located in the Marsdorf district, and is responsible for Toyota's major motorsport development and operations, which in the past included the FIA Formula One World Championship, the FIA World Rally Championship and the Le Mans Series.", "Currently they are working on Toyota's team Toyota Gazoo Racing which competes in the FIA World Endurance Championship.Cologne is considered \"the secret golf capital of Germany\".", "The first golf club in North Rhine-Westphalia was founded in Cologne in 1906.The city offers the most options and top events in Germany.The city has hosted several athletic events which includes the 2005 FIFA Confederations Cup, 2006 FIFA World Cup, 2007 World Men's Handball Championship, 2010 and 2017 Ice Hockey World Championships and 2010 Gay Games.Since 2014, the city has hosted ESL One Cologne, one of the biggest CS GO tournaments held annually in July/August at Lanxess Arena.Furthermore Cologne is home of the Sport-Club Colonia 1906, Germany's oldest boxing club, and the Kölner Athleten-Club 1882, the world's oldest active weightlifting club." ], [ "Notable people", "* Paul-Jürgen Weber, visual artist and photographer" ], [ "Twin towns – sister cities", "Cologne is twinned with:* Barcelona, Spain (1984)* Beijing, China (1987)* Bethlehem, Palestine (1996)* Cluj-Napoca, Romania (1976)* Corinto, Nicaragua (1988)* Cork, Ireland (1988)* Esch-sur-Alzette, Luxembourg (1958)* Indianapolis, United States (1988)* Istanbul, Turkey (1997)* Katowice, Poland (1991)* Kyoto, Japan (1963)* Liège, Belgium (1958)* Lille, France (1958)* Liverpool, England, United Kingdom (1952)* Neukölln (Berlin), Germany (1967)* El Realejo, Nicaragua (1988)* Rio de Janeiro, Brazil (2011)* Rotterdam, Netherlands (1958)* Tel Aviv, Israel (1979)* Thessaloniki, Greece (1988)* Treptow-Köpenick (Berlin), Germany (1990)* Tunis, Tunisia (1964)* Turin, Italy (1958)* Turku, Finland (1967)Cologne also cooperates with:* Dnipro, Ukraine (2022)===Former twin towns===* Volgograd, Russia (1988) - suspended in 2022" ], [ "See also", "* Stadtwerke Köln, the municipal infrastructure company, operator of the city's railways, ports, and other utilities* New Year's Eve sexual assaults in Germany* Hänneschen-Theater" ], [ "References" ], [ "External links", "*" ] ]
wikipedia
[ [ "Buddhist cuisine" ], [ "Introduction", "'''Buddhist cuisine''' is an Asian cuisine that is followed by monks and many believers from areas historically influenced by Mahayana Buddhism.", "It is vegetarian or vegan, and it is based on the Dharmic concept of ahimsa (non-violence).", "Vegetarianism is common in other Dharmic faiths such as Hinduism, Jainism and Sikhism, as well as East Asian religions like Taoism.", "While monks, nuns and a minority of believers are vegetarian year-round, many believers follow the Buddhist vegetarian diet for celebrations.Buddhists believe that cooking is seen as a spiritual practice that produces the nourishment which the body needs to work hard and meditate.", "The origin of \"Buddhist food\" as a distinct sub-style of cuisine is tied to monasteries, where one member of the community would have the duty of being the head cook and supplying meals that paid respect to the strictures of Buddhist precepts.", "Temples that were open to visitors from the general public might also serve meals to them and a few temples effectively run functioning restaurants on the premises.", "In Japan, this culinary custom, recognized as ''shōjin ryōri'' (精進料理) or devotion cuisine, is commonly offered at numerous temples, notably in Kyoto.", "This centuries-old culinary tradition, primarily associated with religious contexts, is seldom encountered beyond places like temples, religious festivals, and funerals.", "A more recent version, more Chinese in style, is prepared by the Ōbaku school of zen, and known as ; this is served at the head temple of Manpuku-ji, as well as various subtemples.", "In modern times, commercial restaurants have also latched on to the style, catering both to practicing and non-practicing lay people." ], [ "Philosophies governing food", "=== Vegetarianism ===Most of the dishes considered to be uniquely Buddhist are vegetarian, but not all Buddhist traditions require vegetarianism of lay followers or clergy.", "Vegetarian eating is primarily associated with the East and Southeast Asian tradition in China, Vietnam, Japan, and Korea where it is commonly practiced by clergy and may be observed by laity on holidays or as a devotional practice.In the Mahayana tradition, several sutras of the Mahayana canon contain explicit prohibitions against consuming meat, including sections of the Lankavatara Sutra and Surangama Sutra.", "The monastic community in Chinese Buddhism, Vietnamese Buddhism and most of Korean Buddhism strictly adhere to vegetarianism.", "Theravada Buddhist monks and nuns consume food by gathering alms themselves, and generally must eat whatever foods are offered to them, including meat.", "The exception to this alms rule is when monks and nuns have seen, heard or known that animal(s) have been specifically killed to feed the alms-seeker, in which case consumption of such meat would be karmically negative, as well as meat from certain animals, such as dogs and snakes, that were regarded as impure in ancient India.", "The same restriction is also followed by some lay Buddhists and is known as the consumption of \"triply clean meat\" (三净肉).", "The Pāli Scriptures also indicated that Lord Buddha refusing a proposal by his traitor disciple Devadatta to mandate vegetarianism in the monastic precepts.Tibetan Buddhism has long accepted that the practical difficulties in obtaining vegetables and grains within most of Tibet make it impossible to insist upon vegetarianism; however, many leading Tibetan Buddhist teachers agree upon the great worth of practicing vegetarianism whenever and wherever possible, such as Chatral Rinpoche, a lifelong advocate of vegetarianism who famously released large numbers of fish caught for food back into the ocean once a year, and who wrote about the practice of saving lives.Both Mahayana and Theravada Buddhists consider that one may practice vegetarianism as part of cultivating Bodhisattvas's paramita.=== Other restrictions ===Shōjin-ryōri served at Mount Koya, JapanIn addition to the ban on garlic, practically all Mahayana monastics in China, Korea, Vietnam and Japan specifically avoid eating strong-smelling plants, traditionally asafoetida, shallot, mountain leek and ''Allium chinense'', which together with garlic are referred to as ''wǔ hūn'' (五葷, or 'Five Acrid and Strong-smelling Vegetables') or ''wǔ xīn'' (五辛 or 'Five Spices') as they tend to excite senses.", "This is based on teachings found in the Brahamajala Sutra, the Surangama Sutra and the Lankavatara Sutra.", "In modern times this rule is often interpreted to include other vegetables of the onion genus, as well as coriander.", "The origin of this additional restriction is from the Indic region and can still be found among some believers of Hinduism and Jainism.The consumption of non-vegetarian food by strict Buddhists is also subject to various restrictions.", "As well as the aforementioned \"triply clean meat\" rule followed by Theravada monks, nuns, and some lay Buddhists, many Chinese Buddhists avoid the consumption of beef, large animals, and exotic species.", "Some Buddhists abstain from eating offal (organ meat), known as ''xiàshui'' (下水).Alcohol and other drugs are also avoided by many Buddhists because of their effects on the mind and \"mindfulness\".", "It is part of the Five Precepts which dictate that one is not to consume \"addictive materials\".", "Caffeinated drinks are not included under this restriction.=== Simple and natural ===In theory and practice, many regional styles of cooking may be adapted to be \"Buddhist\" as long as the cook, with the above restrictions in mind, prepares the food, generally in simple preparations, with expert attention to its quality, wholesomeness and flavor.", "Often working on a tight budget, the monastery cook would have to make the most of whatever ingredients were available.In ''Tenzo kyokun'' (\"Instructions for the Zen Cook\"), Soto Zen founder Eihei Dogen wrote:In preparing food, it is essential to be sincere and to respect each ingredient regardless of how coarse or fine it is.", "(...) A rich buttery soup is not better as such than a broth of wild herbs.", "In handling and preparing wild herbs, do so as you would the ingredients for a rich feast, wholeheartedly, sincerely, clearly.", "When you serve the monastic assembly, they and you should taste only the flavour of the Ocean of Reality, the Ocean of unobscured Awake Awareness, not whether or not the soup is creamy or made only of wild herbs.", "In nourishing the seeds of living in the Way, rich food and wild grass are not separate." ], [ "Ingredients", "Vegetarian dishes at a Buddhist restaurant in Ho Chi Minh cityFollowing its dominant status in most parts of East Asia where Buddhism is most practiced, rice features heavily as a staple in the Buddhist meal, especially in the form of rice porridge or congee as the usual morning meal.", "Noodles and other grains may often be served as well.", "Vegetables of all sorts are generally either stir-fried or cooked in vegetarian broth with seasonings and may be eaten with various sauces.", "Traditionally eggs and dairy are not permitted.", "Seasonings will be informed by whatever is common in the local region; for example, soy sauce and vegan dashi figure strongly in Japanese monastery food while curry and tương (as a vegetarian replacement for fish sauce) may be prominent in Southeast Asia.", "Sweets and desserts are not often consumed, but are permitted in moderation and may be served at special occasions, such as in the context of a tea ceremony in the Zen tradition.Buddhist vegetarian chefs have become extremely creative in imitating meat using prepared wheat gluten, also known as seitan, kao fu (烤麸) or wheat meat, soy (such as tofu or tempeh), agar, konnyaku and other plant products.", "Some of their recipes are the oldest and most-refined meat analogues in the world.", "Soy and wheat gluten are very versatile materials, because they can be manufactured into various shapes and textures, and they absorb flavorings (including, but not limited to, meat-like flavorings), while having very little flavor of their own.", "With the proper seasonings, they can mimic various kinds of meat quite closely.Some of these Buddhist vegetarian chefs are in the many monasteries and temples which serve allium-free and mock-meat (also known as 'meat analogues') dishes to the monks and visitors (including non-Buddhists who often stay for a few hours or days, to Buddhists who are not monks, but staying overnight for anywhere up to weeks or months).", "Many Buddhist restaurants also serve vegetarian, vegan, non-alcoholic or allium-free dishes.Some Buddhists eat vegetarian on the 1st and 15th of the lunar calendar (lenten days), on Chinese New Year eve, and on saint and ancestral holy days.", "To cater to this type of customer, as well as full-time vegetarians, the menu of a Buddhist vegetarian restaurant usually shows no difference from a typical Chinese or East Asian restaurant, except that in recipes originally made to contain meat, a soy chicken substitute might be served instead." ], [ "Variations by sect or region", "According to cookbooks published in English, formal monastery meals in the Zen tradition generally follow a pattern of \"three bowls\" in descending size.", "The first and largest bowl is a grain-based dish such as rice, noodles or congee; the second contains the protein dish which is often some form of stew or soup; the third and smallest bowl is a vegetable dish or a salad." ], [ "See also", "* Buddha's delight* Buddhist ethics* Buddhist vegetarianism* Cultural elements of Buddhism* Index of Buddhism-related articles* List of diets* Secular Buddhism* Vegetarian cuisine* Vegetarianism and religion* Korean temple cuisine* Kaiseki" ], [ "References" ], [ "External links", "* Shabkar.org: Vegetarianism as a way of life for Buddhists* Shojin Ryori: Vegetarian Cooking* Tantras on Buddhist food* Sutras on vegetarianism* Return To The Middle Kingdom: Chinese Vegetarian Eating in East Asia* Toshio Tanahashi* vegetarian-china.info* Daigo: a MICHELIN Guide Restaurant" ] ]
wikipedia
[ [ "Charles V" ], [ "Introduction", "'''Charles V''' may refer to:* Charles V, Holy Roman Emperor (1500–1558)* Charles V of Naples (1661–1700), better known as Charles II of Spain* Charles V of France (1338–1380), called the Wise* Charles V, Duke of Lorraine (1643–1690)* Infante Carlos of Spain, Count of Molina (1788–1855), first Carlist pretender to the throne of Spain (as Charles V)" ], [ "See also", "* Karl V (opera)* Carlos V (chocolate bar)* King Charles (disambiguation)* Charles" ] ]
wikipedia
[ [ "Constantin von Tischendorf" ], [ "Introduction", "'''Lobegott Friedrich Constantin (von) Tischendorf''' (18 January 18157 December 1874) was a German biblical scholar.", "In 1844, he discovered the world's oldest and most complete Bible dated to around the mid-4th century and called Codex Sinaiticus after Saint Catherine's Monastery at Mount Sinai.Tischendorf was made an honorary doctor by the University of Oxford on 16 March 1865, and by the University of Cambridge on 9 March 1865 following his discovery.", "While a student gaining his academic degree in the 1840s, he earned international recognition when he deciphered the ''Codex Ephraemi Rescriptus'', a 5th-century Greek manuscript of the New Testament." ], [ "Early life and education", "Title page from Tischendorf's facsimile edition of the Codex Sinaiticus, published in 1862Tischendorf was born in Lengenfeld, Saxony, the son of a forensic physician.", "After attending primary school in Lengenfield, he went to grammar school in nearby Plauen.", "From Easter 1834, having achieved excellent marks at school, he studied theology and philosophy at the University of Leipzig.", "At Leipzig he was mainly influenced by JGB Winer, and he began to take special interest in New Testament criticism.", "Winer's influence gave him the desire to use the oldest manuscripts in order to compile the text of the New Testament as close to the original as possible.", "Despite his father's death in 1835 and his mother just a year later, he was still able to achieve his doctorate in 1838, before accepting a tutoring job in the home of Reverend Ferdinand Leberecht Zehme in Grossstadeln where he met and fell in love with the clergyman's daughter Angelika.", "He published a volume of poetry in 1838, Maiknospen (Buds of May) and Der junge Mystiker (The Young Mystic) was published under a pseudonym in 1839.At this time he also began his first critical edition of the NewTestament in Greek which was to become his life's work.After a journey through southern Germany and Switzerland, and a visit to Strassburg, he returned to Leipzig to begin work on a critical study of the New Testament text." ], [ "Career", "In 1840, he qualified as university lecturer in theology with a dissertation on the recensions of the New Testament text, the main part of which reappeared the following year in the prolegomena to his first edition of the Greek New Testament.", "These early textual studies convinced him of the absolute necessity of new and more exact collations of manuscripts.From October 1840 until January 1843 he was in Paris, busy with the treasures of the Bibliothèque Nationale, eking out his scanty means by making collations for other scholars, and producing for the publisher, Firmin Didot, several editions of the Greek New Testament, one of them exhibiting the form of the text corresponding most closely to the Vulgate.", "His second edition retracted the more precarious readings of the first, and included a statement of critical principles that is a landmark for evolving critical studies of Biblical texts.A great triumph of these laborious months was the decipherment of the palimpsest ''Codex Ephraemi Syri Rescriptus'', of which the New Testament part was printed before he left Paris, and the Old Testament in 1845.His success in dealing with a manuscript that, having been over-written with other works of Ephrem the Syrian, had been mostly illegible to earlier collators, made him more well known, and gained support for more extended critical expeditions.", "He now became ''professor extraordinarius'' at Leipzig, where he was married in 1845.He also began to publish ''Reise in den Orient'', an account of his travels in the east (in 2 vols., 1845–46, translated as ''Travels in the East'' in 1847).", "Even though he was an expert in reading the text of a palimpsest (this is a document where the original writing has been removed and new writing added), he was not able to identify the value or meaning of the ''Archimedes Palimpsest'', a torn leaf of which he held and after his death was sold to the Cambridge University Library.Tischendorf briefly visited the Netherlands in 1841 and England in 1842.In 1843 he visited Italy for thirteen months, before continuing on to Egypt, Sinai, and the Levant, returning via Vienna and Munich.=== Discovery of the Codex Sinaiticus Bible manuscripts ===In 1844 Tischendorf travelled the first time to Saint Catherine's Monastery at the foot of Mount Sinai in Egypt, where he found a portion of what would later be hailed as the oldest complete known New Testament.", "Of the many pages which were contained in an old wicker basket (the kind that the monastery hauled in its visitors as customary in unsafe territories) he was given 43 pages containing a part of the Old Testament as a present.", "He donated those 43 pages to King Frederick Augustus II of Saxony (reigned 1836–1854), to honour him and to recognise his patronage as the funder of Tischendorf's journey.", "(Tischendorf held a position as Theological Professor at Leipzig University, also under the patronage of Frederick Augustus II.)", "Leipzig University put two of the leaves on display in 2011.Tischendorf reported in his 1865 book ''Wann Wurden Unsere Evangelen Verfasst'', translated to English in 1866 as ''When Were Our Gospels Written'' in the section \"The Discovery of the Sinaitic Manuscript\" that he found, in a trash basket, forty-three sheets of parchment of an ancient copy of the Greek Old Testament, reporting that the monks were using the trash to start fires.", "And Tischendorf, horrified, asked if he could have them.", "He deposited them at the University of Leipzig, under the title of the ''Codex Friderico-Augustanus'', a name given in honour of his patron, Frederick Augustus II of Saxony, king of Saxony.", "The fragments were published in 1846, although Tischendorf kept the place of discovery a secret.Many have expressed skepticism at the historical accuracy of this report of saving a 1500-year-old parchment from the flames.", "J. Rendel Harris referred to the story as a ''myth''.", "The Tischendorf Lesebuch (see References) quotes that the Librarian Kyrillos mentioned to Tischendorf that the contents of the basket had already twice been submitted to the fire.", "The contents of the baskets were damaged scriptures, the third filling apparently, so cited by Tischendorf himself.see Tischendorf Lesebuch, Tischendorf's own account.", "In 1853 Tischendorf made a second trip to the Syrian monastery but made no new discoveries.", "He returned a third time in January 1859 under the patronage of Tsar Alexander II of Russia with the active aid of the Russian government to find more of the ''Codex Frederico-Augustanus'' or similar ancient Biblical texts.", "On 4 February, the last day of his visit, he was shown a text which he recognized as significant – the ''Codex Sinaiticus'' – a Greek manuscript of the complete New Testament and parts of the Old Testament dating to the 4th century.Tischendorf persuaded the monks to present the manuscript to Tsar Alexander II of Russia, at the cost of the Tsar it was published in 1862 (in four folio volumes).", "Those ignorant of the details of his discovery of the ''Codex Sinaiticus'' accused Tischendorf of buying manuscripts from ignorant monastery librarians at low prices.", "Indeed, he was never rich, but he staunchly defended the rights of the monks at Saint Catherine's Monastery when he persuaded them eventually to send the manuscript to the Tsar.", "This took approximately 10 years because the abbot of St Catherines had to be re-elected and confirmed in office in Cairo and in Jerusalem, and during those 10 years no one in the monastery had the authority to hand over any documents.", "However the documents were handed over in due course following a signed and sealed letter to the Tsar Alexander II (Schenkungsurkunde).", "Even so, the monks of Mt.", "Sinai still display a receipt-letter from Tischendorf promising to return the manuscript to them in the case that the donation can not be done.", "This token-letter had to be destroyed, following the late issue of a \"Schenkungsurkunde\".", "This donation act regulated the Codex exchange with the Tsar, against 9000 Rubels and Rumanian estate protection.", "The Tsar was seen as the protector of Greek-Orthodox Christians.", "Thought lost since the Russian revolution, the document (Schenkungsurkunde) has now resurfaced in St Petersburg 2003, and has also been long before commented upon by other scholars like Kurt Aland.", "The monastery has disputed the existence of the gift certificate (Schenkungsurkunde) since the British Library was named as the new owner of the Codex.", "Now following the late find of the gift certificate by the National Russian Library the existence cannot be disputed in earnest.", "In 1869 the Tsar awarded Tischendorf the style of \"von\" Tischendorf as a Russian noble.", "327 facsimile editions of the Codex were printed in Leipzig for the Tsar (instead of a salary for the three-year work of Tischendorf the Tsar gave him 100 copies for reselling) in order to celebrate the 1000th anniversary of the traditional foundation of the Rus' state in 862 with the publication of this most amazing find.", "Supporting the production of the facsimile, all made with special print characters for each of the 4 scribes of the Codex Sinaiticus, was shift work and contributed to Tischendorf's early demise due to exhausting work for months also during nights.", "Thus the Codex found its way to the Imperial Library at St. Petersburg.When the 4-volume luxury edition of the Sinai Bible was completed in 1862, C. Tischendorf presented the original ancient manuscript to Emperor Alexander II.", "Meanwhile, the question of transferring the manuscript to the full possession of the Russian Sovereign remained unresolved for some years.", "In 1869, the new Archbishop of Sinai, Callistratus, and the monastic community, signed the official certificate presenting the manuscript to the Tsar.", "The Russian Government, in turn, bestowed the Monastery with 9000 rubles and decorated the Archbishop and some of the brethren with orders.", "In 1933 the Soviet Government sold the Codex Sinaiticus for 100,000 pounds to the British Museum in London, England.", "The official certificate with signatures in Russian/ French/ Greek sections has been refound in St Petersburg.=== Novum Testamentum Graece – publication with 21 editions ===In the winter of 1849 the first edition of his great work now titled ''Novum Testamentum Graece.", "Ad antiquos testes recensuit.", "Apparatum criticum multis modis'' appeared (translated as ''Greek New Testament.", "The ancient witnesses reviewed.", "Preparations critical in many ways''), containing canons of criticism, adding examples of their application that are applicable to students today:Basic rule: \"The text is only to be sought from ancient evidence, and especially from Greek manuscripts, but without neglecting the testimonies of versions and fathers.", "\"#\"A reading altogether peculiar to one or another ancient document is suspicious; as also is any, even if supported by a class of documents, which seems to evince that it has originated in the revision of a learned man.", "\"#\"Readings, however well supported by evidence, are to be rejected, when it is manifest (or very probable) that they have proceeded from the errors of copyists.", "\"#\"In parallel passages, whether of the New or Old Testament, especially in the Synoptic Gospels, which ancient copyists continually brought into increased accordance, those testimonies are preferable, in which precise accordance of such parallel passages is not found; unless, indeed, there are important reasons to the contrary.", "\"#\"In discrepant readings, that should be preferred which may have given occasion to the rest, or which appears to comprise the elements of the others.", "\"#\"Those readings must be maintained which accord with New Testament Greek, or with the particular style of each individual writer.", "\"These were partly the result of the tireless travels he had begun in 1839 in search of unread manuscripts of the New Testament, \"to clear up in this way,\" he wrote, \"the history of the sacred text, and to recover if possible the genuine apostolic text which is the foundation of our faith.", "\"In 1850 appeared his edition of the ''Codex Amiatinus'' (in 1854 corrected) and of the Septuagint version of the Old Testament (7th ed., 1887); in 1852, amongst other works, his edition of the ''Codex Claromontanus''.", "In 1859, he was named ''professor ordinarius'' of theology and of Biblical paleography, this latter professorship being specially created for him; and another book of travel, ''Aus dem heiligen Lande'', appeared in 1862.Tischendorf's Eastern journeys were rich enough in other discoveries to merit the highest praise.Besides his fame as a scholar, he was a friend of both Robert Schumann, with whom he corresponded, and Felix Mendelssohn, who dedicated a song to him.", "His colleague Samuel Prideaux Tregelles wrote warmly of their mutual interest in textual scholarship.", "His personal library, purchased after his death, eventually came to the University of Glasgow, where a commemorative exhibition of books from his library was held in 1974 and can be accessed by the public." ], [ "Death", "Lobegott Friedrich Constantin (von) Tischendorf died in Leipzig on 7 December 1874, aged 59." ], [ "Codex Sinaiticus", "The ''Codex Sinaiticus'' contains a 4th-century manuscript of New Testament texts.", "Two other Bibles of similar age exist, though they are less complete: Codex Vaticanus in the Vatican Library and Codex Alexandrinus, currently owned by the British Library.", "The Codex Sinaiticus is deemed by some to be the most important surviving New Testament manuscript, as no older manuscript is as nearly complete as the Codex.", "The codex can be viewed in the British Library in London, or as a digitized version on the Internet." ], [ "Tischendorf's motivation", "Throughout his life Tischendorf sought old biblical manuscripts, as he saw it as his task to give theology a Greek New Testament which was based on the oldest possible scriptures.", "He intended to be as close as possible to the original sources.", "Tischendorf's greatest discovery was in the monastery of Saint Catherine on the Sinai Peninsula, which he visited in May 1844, and again in 1853 and 1859 (as Russian envoy).In 1862 Tischendorf published the text of the Codex Sinaiticus for the 1000th Anniversary of the Russian Monarchy in both an illustrious four-volume facsimile edition and in a less costly text edition, to enable all scholars to have access to the Codex.Tischendorf pursued a constant course of editorial labours, mainly on the New Testament, until he was broken down by overwork in 1873.His motive, as explained in a publication on Tischendorf's Letter by Prof. Christfried Boettrich (Leibzig University, Prof. of Theology), was to prove scientifically that the words of the Bible were trustfully transmitted over centuries.", ":de:Christfried Böttrich" ], [ "Works", "Matthew 26:52–69 in Tischendorf's facsimile edition (1843)His ''magnum opus'' was the \"Critical Edition of the New Testament.", "\"The great edition, of which the text and apparatus appeared in 1869 and 1872, was called by himself ''editio viii''; but this number is raised to twenty or twenty-one, if mere reprints from stereotype plates and the minor editions of his great critical texts are included; posthumous prints bring the total to forty-one.", "Four main recensions of Tischendorf's text may be distinguished, dating respectively from his editions of 1841, 1849, 1859 (ed.", "vii), and 1869–72 (ed.", "viii).", "The edition of 1849 may be regarded as historically the most important, from the mass of new critical material it used; that of 1859 is distinguished from Tischendorf's other editions by coming nearer to the received text; in the eighth edition, the testimony of the Sinaitic manuscript received great (probably too great) weight.", "The readings of the Vatican manuscript were given with more exactness and certainty than had been possible in the earlier editions, and the editor had also the advantage of using the published labours of his colleague and friend Samuel Prideaux Tregelles.Of relatively lesser importance was Tischendorf's work on the Greek Old Testament.", "His edition of the Roman text, with the variants of the Alexandrian manuscript, the ''Codex Ephraemi'', and the ''Friderico-Augustanus'', was of service when it appeared in 1850, but, being stereotyped, was not greatly improved in subsequent issues.", "Its imperfections, even within the limited field it covers, may be judged by the aid of Eberhard Nestle's appendix to the 6th issue (1880).Besides this may be mentioned editions of the New Testament apocrypha, ''De Evangeliorum apocryphorum origine et usu'' (1851); ''Acta Apostolorum apocrypha'' (1851); ''Evangelia apocrypha'' (1853; 2nd ed., 1876); ''Apocalypses apocryphae'' (1866), and various minor writings, partly of an apologetic character, such as ''Wann wurden unsere Evangelien verfasst?''", "(''When Were Our Gospels Written?", "''; 1865; 4th ed., 1866, digitized by Google and available for e-readers), ''Haben wir den echten Schrifttext der Evangelisten und Apostel?''", "(1873), and ''Synopsis evangelica'' (7th ed., 1898).=== Facsimile of manuscripts ===* ''Codex Ephraemi Syri rescriptus, sive Fragmenta Novi Testamenti'', Lipsiae 1843* ''Codex Ephraemi Syri rescriptus, sive Fragmenta Veteris Testamenti'', Lipsiae 1845* Notitia editionis codicis Bibliorum Sinaitici (Leipzig 1860)* ''Anecdota sacra et profana'' (Leipzig 1861)=== Editions of Novum Testamentum Graece ===* ''Novum Testamentum Graece.", "Editio stereotypa secunda'', (Lipsiae 1862)* ''Novum Testamentum Graece''.", "Editio Quinta, Lipsiae 1878* ''Novum Testamentum Graece''.", "Editio Septima, Lipsiae 1859=== Editio Octava ===* Gospels: ''Novum Testamentum Graece: ad antiquissimos testes denuo recensuit, apparatum criticum omni studio perfectum'', vol.", "I (1869)* Acts–Revelation: ''Novum Testamentum Graece.", "Editio Octava Critica Maior'', vol.", "II (1872)* Prolegomena I–VI: ''Novum Testamentum Graece.", "Editio Octava Critica Maior'', vol.", "III, Part 1 (1884)* Prolegomena VII–VIII: ''Novum Testamentum Graece.", "Editio Octava Critica Maior'', vol.", "III, Part 2 (1890)* Prolegomena IX–XIII: ''Novum Testamentum Graece.", "Editio Octava Critica Maior'', vol.", "III, Part 3 (1894)* Novum Testamentum graece: recensionis Tischendorfianae ultimae textum.", "Lipsiae 1881=== LXX ===* Vetus Testamentum Graece iuxta LXX interpretes: Vetus Testamentum Graece iuxta LXX (Volume 1)* Vetus Testamentum Graece iuxta LXX interpretes: Vetus Testamentum Graece iuxta LXX (Volume 2)===His publications continued===* Doctrina Pauli apostoli de vi mortis Christi satisfactoria.", "Leipzig, 1837 Google* Fritz der junge Mystiker, oder die drei letzten Festzeiten aus seinem Leben...: eine biographische Skizze.", "Leipzig, 1839* Disputatio de Christo, pane vitae, sive de loco Evang.", "Ioann.", "c. VI.", "vv.", "5159 Leipzig, 1839* Die Geissler: namentlich die große Geißelfahrt nach Straßburg im Jahre 1349.Leipzig, 1840* De ev.", "Matth.", "c. 19.v.", "16 et 39.Leipzig, 1840* De recensionibus quas dicunt textus Novi Testamenti ratione potissimum habita Scholzii: dissertatio historica exegetica critica.", "Leipzig, 1840 Hochschulschrift* Novum Testamentum Graece / Ad Antiquos Testes Recensuit Lectionesque Variantes Elzeviriorum Stephani Griesbachii Notavit Constantinus Tischendorf.", "Paris, 1842* Hē Kainē Diathēkē / In Antiquis Testibus Textum Versionis Vulgatae Latinae Indagavit Lectionesque Variantes Stephani Et Griesbachii Notavit V. S. Venerabili Jager in Consilium Adhibito Constantinus Tischendorf.", "Paris, 1842* Codex Ephraemi Syri rescriptus sive fragmenta utriusque testamenti.", "T.1.Fragmenta Veteris testamenti, T. 2.Fragmenta Novi testamenti.", "Leipzig, 1843* Weihnachtspredigt ... in Lengefeld.", "Leipzig, 1845* Monumenta sacra inedita sive reliquiae antiquissimae textus Novi testamenti Graeci: ex novum plus mille annorum codicibus per Europam dispersis.", "Leipzig, 1846* Codex Friderico-Augustanus sive fragmenta Veteris Testamenti: e codice Graeco, omnium qui in Europa supersunt facile antiquissimo; in Oriente detexit, in patriam attulit.", "Leipzig, 1846* De Israelitarum per mare rubrum transitu: cum tabula.", "Leipzig, 1847* Evangelium Palatinum ineditum sive reliquiae textus Evangeliorum Latini ante Hieronymum versi: ex Codice Palatino Purpureo quarti vel quinti p. Chr.", "saeculi.", "Leipzig, 1847* Der Geist der Wahrheit: Zeitpredigt am Sonntag Cantate den 6.Mai 1849 in der Universitätskirche zu Leipzig gehalten.", "Leipzig, 1849* Novum Testamentum: Latine interprete Hieronymo; ex celeberrimo codice Amiatino omnium et antiquissimo et praestantissimo.", "Leipzig, 1850* Acta apostolorum apocrypha.", "Leipzig, 1851 Google* Synopsis evangelica: ex quattuor evangeliis ordine chronologico concinnavit.", "Leipzig, 1851 Google-USA* (5.Aufl.", "1884)* De evangeliorum apocryphorum origine et usu.", "In: Verhandelingen / uitg.", "door het Haagsche Genootschap tot Verdediging van de christelijke Godsdienst, Bd.", "12, Den Haag, 1851* Codex Claromontanus sive Epistulae Pauli omnes Graece et Latine: ex Codice Parisiensi celeberrimo nomine Claromontani plerumque dicto sexti ut videtur post Christum saeculi.", "Leipzig, 1852* Evangelia apocrypha: adhibitis plurimis codicibus graecis et latinis maximam partem nunc primum consultis atque ineditorum copia insignibus.", "Leipzig, 1853 Google Editio Altera 1874: Google-USA** Novum Testamentum Triglottum: graece, latine, germanice; graecum textum addito lectionum variarum delectu recensuit, latinum Hieronymi notata Clementina lectione ex auctoritate codicum restituit, germanicum ad pristinam lutheranae editionis veritatem revocavit.", "Leipzig, 1854* Anecdota sacra et profana ex oriente et occidente allata sive notitia codicum Graecorum, Arabicorum, Syriacorum, Copticorum, Hebraicorum, Aethiopicorum, Latinorum: cum excerptis multis maximam partem Graecis et 35 scripturarum antiquissimarum speciminibus.", "Leipzig, 1855 Google Editio repetita 1861: Michigan, Google, Google* Pastor: Graece; ex fragmentis Lipsiensibus.", "Leipzig, 1856* Novum Testamentum Graece et Latine: Graecum textum addito lectionum variarum delectu rec.", "; Latinum Hieronymi notata Clementina lectione ex auct.", "codicum.", "Leipzig, 1858* Notitia editionis Codicis Bibliorum Sinaitici auspiciis imperatoris Alexandri II.", "susceptae.", "Leipzig, 1860* Aus dem heiligen Lande: nebst fünf Abbildungen in Holzschnitt und einer lithographirten Tafel.", "Leipzig, 1862* Vorworte zur sinaitischen Bibelhandschrift zu St. Petersburg : unter den Auspicien seiner Kaiserlichen Maiestät Alexander II.", "dem Dunkel entzogen, nach Europa überbracht, zur Hebung und Verherrlichung christlicher Wissenschaft.", "Leipzig, 1862* Novum Testamentum Sinaiticum sive Novum Testamentum cum Epistola Barnabae et Fragmentis Pastoris : ex codice Sinaitico ... Leipzig, 1863* Die Anfechtungen der Sinai-Bibel.", "Leipzig, 1865 Google* Aus Dem Heiligen Lande.", "Leipzig, 1865 Google* Wann wurden unsere Evangelien verfasst?", "Leipzig, 1865 Google, 2.Expl.", "Google* Novum Testamentum Graece: ex sinaitico codice omnium antiquissimo vaticana itemque Elzeviriana lectione notata.", "Leipzig, 1865* Apocalypses apocryphae Mosis, Esdrae, Pauli, Johannis, item Mariae Dormitio: additis Evangeliorum et actuum Apocryphorum supplementis.", "Leipzig, 1866 Internet Archive Internet Archive* Appendix Codicum celeberrimorum Sinaitici, Vaticani, Alexandrini cum imitatione ipsorum antiqua manu scriptorum.", "Leipzig, 1867* Philonea: inedita altera, altera nunc demum recte ex vetere scriptura eruta.", "Leipzig, 1868 Internet Archive* Responsa ad calumnias romanas: item supplementum novi testamenti ex sinaitico codice anno 1865 editi.", "Leipzig, 1870* Novum Testamentum graece: ad antiquissimos testes denuo recensuit, apparatum.", "Leipzig, 1869–1872.1.Band 1869 Google-USA*, 2.Band 1872 Google-USA** Die Sinaibibel, ihre Entdeckung, Herausgabe und Erwerbung.", "Leipzig, 1871 Google-USA** Die evangelische Alliance-Deputation an Kaiser Alexander zu Friedrichshafen: zur Abwehr der groben Entstellungen und Verleumdungen des Herrn von Wurstemberger (zu Bach bei Bern).", "Leipzig, 1872* Clementis Romani epistulae.", "Ad ipsius codicis alexandrini fidem ac modum repetitis curis edidit Constantinus de Tischendorf.", "Leipzig, 1873.Internet Archive* Haben wir den ächten Schrifttext der Evangelisten und Apostel?", "Leipzig, 1873 Google-USA* (2.Aufl.", ")* Liber Psalmorum: hebraicus atque latinus ab Hieronymo ex hebraeo conversus.", "Leipzig, 1874===Cooperation===* Textum ... recensuit, brevem apparatum criticum una cum variis lectionibus Elzevirorum, Knapii, Scholzii, Lachmanni subjunxit, argumenta et locos parallelos indicavit, commentationem ... edd.", "Stephanicae tertiae atque Millianae, Matthaeianae, Griesbachianae praemisit Aenoth.", "Frid.", "Const.", "Tischendorf.", "Leipzig, 1841* Clementinorum Epitomae duae: altera edita correctior, inedita altera nunc primum integra ex codicibus Romanis et excerptis Tischendorfianis, cura Alberti Rud.", "Max.", "Dressel.", "Accedunt Friderici Wieseleri Adnotationes criticae ad Clementis Romani quae feruntur homilias.", "Leipzig, 1859 Internet Archive* Ad Vetus Testamentum Graecum ex auctoritate Sixti V. Pont.", "Max.", "a.", "1587 editum a Leandro van Ess quoad textum accuratissime recusum trecentis annis post editionem originalem novis curis iteratum prolegomena et epilegomena.", "Bredt, 1887* Novum Testamentum : Constantin Tischendorf: griechisch, lateinisch, englisch, Ostervald: französisch, Martin Luther, DeWette, Richard Nagel: deutsch ... Hrsg.", "Eugen Niethe Berlin, 1891===Second Author===* Ezra Abbot: The late Professor Tischendorf.", "Aus: The Unitarian Review and Religious Magazine.", "März 1875 (Festschrift Konstantin von Tischendorf)* Caspar René Gregory: Tischendorf, Lobegott Friedrich Constantin.", "In: Allgemeine Deutsche Biographie.", "Band 38.Duncker & Humblot, Leipzig 1894, S. 371–373" ], [ "See also", "* List of New Testament papyri* List of New Testament uncials* Agnes and Margaret Smith* Editio Octava Critica Maior" ], [ "Footnotes" ], [ "References", "* Black, Matthew, and Robert Davidson, ''Constantin von Tischendorf and the Greek New Testament'' Glasgow: University of Glasgow Press, 1981.", "* * Christfried Böttrich: ''\"One Story – Different Perspectives.", "The Case of the Codex Sinaiticus\"'', in: Codex Sinaiticus - New Perspectives on the Ancient Biblical Manuscript, Scot McKendrick, David Parker, Amy David Myshrall, Cillian O'Hogan (Hg.", "), London 2015 (Papers from the Sinaticus-Conference July 2009 in the British Library London).", "* * * In addition to the handbooks on New Testament criticism, Carl Bertheau's article on Tischendorf in Herzog-Hauck, ''Realencyklopädie'' (3rd ed., 1907)* * THE HISTORY OF THE ACQUISITION OF THE SINAI BIBLE BY THE RUSSIAN GOVERNMENT IN THE CONTEXT OF RECENT FINDINGS IN RUSSIAN ARCHIVES1, A.V.", "Zakharova* Bibliographie Konstantin von Tischendorf (1815–1874), Christfried Bőttrich* Tischendorf Lesebuch, Christfried Bőttrich, 1999* Tischendorf Erinnerungen, Ludwig Schneller, Verlag der St-Johannis Druckerei, Schweickhardt, Lahr-Dinglingen, 1991* Various Tischendorf publications from Christfried Bőttrich" ], [ "External links", "* Tischendorf.", "V. Various Works.", "Codices, Synoptics, Testaments, Anecdotes, Criticism.", "12 vols.", "1845–1880* Monumenta sacra inedita.", "Nova Collectio, 1–6 volumes (1857–1870) at the Internert Archive* Tischendorf Internet Archive=== Sortable articles ===* Works by Von Tischendorf in English at CCEL* Tischendorf's eighth Greek New Testament with morphological tags and lemmas* Comparison of Tischendorf's 8th GNT text with other manuscript editions on the Manuscript Comparator* A digital edition of the Evangelia Apocrypha document written in Latin and Greek, in pdf format.", "* Novum Testamentum graece (1859)* Complete Apparatus, 8th Version in pdf –" ] ]
wikipedia
[ [ "Calvin Coolidge" ], [ "Introduction", "'''Calvin Coolidge''' (born '''John Calvin Coolidge Jr.'''; ; July 4, 1872January 5, 1933) was an American attorney and politician who served as the 30th president of the United States from 1923 to 1929.Born in Vermont, Coolidge was a Republican lawyer from New England who climbed the ladder of Massachusetts politics, becoming the state's 48th governor.", "His response to the Boston police strike of 1919 thrust him into the national spotlight as a man of decisive action.", "The next year, Coolidge was elected the country's 29th vice president and succeeded the presidency upon the sudden death of President Warren G. Harding in 1923.Elected in his own right in 1924, Coolidge gained a reputation as a small-government conservative with a taciturn personality and dry sense of humor that earned him the nickname \"Silent Cal\".", "Though his widespread popularity enabled him to run for a second full term, Coolidge chose not to run again in 1928, remarking that ten years as president would be \"longer than any other man has had ittoo long!", "\"Throughout his gubernatorial career, Coolidge ran on the record of fiscal conservatism, strong support for women's suffrage, and a vague opposition to Prohibition.", "During his presidency, he restored public confidence in the White House after the many scandals of the Harding administration.", "He signed into law the Indian Citizenship Act of 1924, which granted U.S. citizenship to all Native Americans, and oversaw a period of rapid and expansive economic growth known as the \"Roaring Twenties\", leaving office with considerable popularity.", "He was known for his hands-off governing approach and pro-business stances; as biographer Claude Fuess wrote: \"He embodied the spirit and hopes of the middle class, could interpret their longings and express their opinions.", "That he did represent the genius of the average is the most convincing proof of his strength.", "\"Scholars have ranked Coolidge in the lower half of U.S. presidents.", "He gains nearly universal praise for his stalwart support of racial equality during a period of heightened racial tension in the United States, and is highly praised by advocates of smaller government and ''laissez-faire'' economics, while supporters of an active central government generally view him far less favorably.", "His critics argue that he failed to use the country's economic boom to help struggling farmers and workers in other flailing industries, and there is still much debate among historians as to the extent to which Coolidge's economic policies contributed to the onset of the Great Depression." ], [ "Early life and family history", "John Calvin Coolidge Jr. was born on July 4, 1872, in Plymouth Notch, Vermont—the only U.S. president to be born on Independence Day.", "He was the elder of the two children of John Calvin Coolidge Sr. (1845–1926) and Victoria Josephine Moor (1846–1885).", "Although named for his father, from early childhood Coolidge was addressed by his middle name.", "The name Calvin was used in multiple generations of the Coolidge family, apparently selected in honor of John Calvin, the Protestant Reformer.Coolidge Senior engaged in many occupations and developed a statewide reputation as a prosperous farmer, storekeeper, and public servant.", "He held various local offices, including justice of the peace and tax collector and served in both houses of the Vermont General Assembly.", "When Coolidge was 12 years old, his chronically ill mother died at the age of 39, perhaps from tuberculosis.", "His younger sister, Abigail Grace Coolidge (1875–1890), died at the age of 15, probably of appendicitis, when Coolidge was 18.Coolidge's father married a Plymouth schoolteacher in 1891, and lived to the age of 80.Coolidge's family had deep roots in New England.", "His earliest American ancestor, John Coolidge emigrated from Cottenham, Cambridgeshire, England, around 1630 and settled in Watertown, Massachusetts.", "Coolidge's great-great-grandfather, also named John Coolidge, was an American military officer in the Revolutionary War and one of the first selectmen of the town of Plymouth.", "His grandfather Calvin Galusha Coolidge served in the Vermont House of Representatives.", "His cousin Park Pollard was a businessman in Cavendish, Vermont and the longtime chair of the Vermont Democratic Party.", "Coolidge was also a descendant of Samuel Appleton, who settled in Ipswich and led the Massachusetts Bay Colony during King Philip's War.", "Coolidge's mother was the daughter of Hiram Dunlap Moor, a Plymouth Notch farmer, and Abigail Franklin.File:PlymouthVT_CalvinCoolidgeHouse.jpg|The Coolidge Homestead in Plymouth Notch, VermontFile:CoolidgeAmherst.png|Coolidge as an Amherst College undergraduate" ], [ "Early career and marriage", "===Education and law practice===Coolidge attended the Black River Academy and then St. Johnsbury Academy before enrolling at Amherst College, where he distinguished himself in the debating class.", "As a senior, he joined the Phi Gamma Delta fraternity and graduated ''cum laude''.", "While at Amherst, Coolidge was profoundly influenced by philosophy professor Charles Edward Garman, a Congregational mystic who had a neo-Hegelian philosophy.Coolidge explained Garman's ethics forty years later:There is a standard of righteousness that might does not make right, that the end does not justify the means, and that expediency as a working principle is bound to fail.", "The only hope of perfecting human relationships is in accordance with the law of service under which men are not so solicitous about what they shall get as they are about what they shall give.", "Yet people are entitled to the rewards of their industry.", "What they earn is theirs, no matter how small or how great.", "But the possession of property carries the obligation to use it in a larger service...At his father's urging after graduation, Coolidge moved to Northampton, Massachusetts, to become a lawyer.", "Coolidge followed the common practice of apprenticing with a local law firm, Hammond & Field, and reading law with them.", "John C. Hammond and Henry P. Field, both Amherst graduates, introduced Coolidge to practicing law in the county seat of Hampshire County, Massachusetts.", "In 1897, Coolidge was admitted to the Massachusetts bar, becoming a country lawyer.", "With his savings and a small inheritance from his grandfather, Coolidge opened his own law office in Northampton in 1898.He practiced commercial law, believing that he served his clients best by staying out of court.", "As his reputation as a hard-working and diligent attorney grew, local banks and other businesses began to retain his services.===Marriage and family===Coolidge with his family, In 1903, Coolidge met Grace Goodhue, a graduate of the University of Vermont and a teacher at Northampton's Clarke School for the Deaf.", "They married on October 4, 1905, at 2:30 p.m. in a small ceremony which took place in the parlor of Grace's family's house, having overcome her mother's objections to the marriage.", "The newlyweds went on a honeymoon trip to Montreal, originally planned for two weeks but cut short by a week at Coolidge's request.", "After 25 years he wrote of Grace, \"for almost a quarter of a century she has borne with my infirmities and I have rejoiced in her graces\".The Coolidges had two sons: John (1906–2000) and Calvin Jr. (1908–1924).", "On June 30, 1924, Calvin Jr. had played tennis with his brother on the White House tennis courts without putting on socks and developed a blister on one of his toes.", "The blister subsequently degenerated into sepsis.", "Calvin Jr. died a little over a week later at the age of 16.The President never forgave himself for Calvin Jr's death.", "His eldest son John said it \"hurt Coolidge terribly\", and psychiatric biographer Robert E. Gilbert, author of'' The Tormented President: Calvin Coolidge, Death, and Clinical Depression'', said that Coolidge \"ceased to function as President after the death of his sixteen-year-old son\".", "Gilbert explains in his book how Coolidge displayed all ten of the symptoms listed by the American Psychiatric Association as evidence of major depressive disorder following Calvin Jr.'s sudden death.", "John later became a railroad executive, helped to start the Coolidge Foundation, and was instrumental in creating the President Calvin Coolidge State Historic Site.Coolidge was frugal, and when it came to securing a home, he insisted upon renting.", "He and his wife attended Northampton's Edwards Congregational Church before and after his presidency." ], [ "Local political office (1898−1915)", "===City offices===The Republican Party was dominant in New England at the time, and Coolidge followed the example of Hammond and Field by becoming active in local politics.", "In 1896, Coolidge campaigned for Republican presidential candidate William McKinley, and was selected to be a member of the Republican City Committee the next year.", "In 1898, he won election to the City Council of Northampton, placing second in a ward where the top three candidates were elected.", "The position offered no salary but provided Coolidge with valuable political experience.", "In 1899, he was chosen City Solicitor by the City Council.", "He was elected for a one-year term in 1900, and reelected in 1901.This position gave Coolidge more experience as a lawyer and paid a salary of $600 ().", "In 1902, the city council selected a Democrat for city solicitor, and Coolidge returned to private practice.", "Soon thereafter, however, the clerk of courts for the county died, and Coolidge was chosen to replace him.", "The position paid well, but it barred him from practicing law, so he remained at the job for only one year.", "In 1904, Coolidge suffered his sole defeat at the ballot box, losing an election to the Northampton school board.", "When told that some of his neighbors voted against him because he had no children in the schools he would govern, the recently married Coolidge replied, \"Might give me time!", "\"===Massachusetts state legislator and mayor===Coolidge as a state representative in 1908In 1906, the local Republican committee nominated Coolidge for election to the Massachusetts House of Representatives.", "He won a close victory over the incumbent Democrat, and reported to Boston for the 1907 session of the Massachusetts General Court.", "In his freshman term, Coolidge served on minor committees and, although he usually voted with the party, was known as a Progressive Republican, voting in favor of such measures as women's suffrage and the direct election of Senators.", "While in Boston, Coolidge became an ally, and then a liegeman, of then U.S.", "Senator Winthrop Murray Crane who controlled the western faction of the Massachusetts Republican Party; Crane's party rival in the east of the commonwealth was U.S.", "Senator Henry Cabot Lodge.", "Coolidge forged another key strategic alliance with Guy Currier, who had served in both state houses and had the social distinction, wealth, personal charm and broad circle of friends which Coolidge lacked, and which would have a lasting impact on his political career.", "In 1907, he was elected to a second term, and in the 1908 session Coolidge was more outspoken, though not in a leadership position.Instead of vying for another term in the State House, Coolidge returned home to his growing family and ran for mayor of Northampton when the incumbent Democrat retired.", "He was well liked in the town, and defeated his challenger by a vote of 1,597 to 1,409.During his first term (1910 to 1911), he increased teachers' salaries and retired some of the city's debt while still managing to effect a slight tax decrease.", "He was renominated in 1911, and defeated the same opponent by a slightly larger margin.In 1911, the State Senator for the Hampshire County area retired and successfully encouraged Coolidge to run for his seat for the 1912 session; Coolidge defeated his Democratic opponent by a large margin.", "At the start of that term, he became chairman of a committee to arbitrate the \"Bread and Roses\" strike by the workers of the American Woolen Company in Lawrence, Massachusetts.", "After two tense months, the company agreed to the workers' demands, in a settlement proposed by the committee.", "A major issue affecting Massachusetts Republicans that year was the party split between the progressive wing, which favored Theodore Roosevelt, and the conservative wing, which favored William Howard Taft.", "Although he favored some progressive measures, Coolidge refused to leave the Republican party.", "When the new Progressive Party declined to run a candidate in his state senate district, Coolidge won reelection against his Democratic opponent by an increased margin.", "\"Do the day's work.", "If it be to protect the rights of the weak, whoever objects, do it.", "If it be to help a powerful corporation better to serve the people, whatever the opposition, do that.", "Expect to be called a stand-patter, but don't be a stand-patter.", "Expect to be called a demagogue, but don't be a demagogue.", "Don't hesitate to be as revolutionary as science.", "Don't hesitate to be as reactionary as the multiplication table.", "Don't expect to build up the weak by pulling down the strong.", "Don't hurry to legislate.", "Give administration a chance to catch up with legislation.\"", "\"Have Faith in Massachusetts\" as delivered by Calvin Coolidge to the Massachusetts State Senate, 1914In the 1913 session, Coolidge enjoyed renowned success in arduously navigating to passage the Western Trolley Act, which connected Northampton with a dozen similar industrial communities in Western Massachusetts.", "Coolidge intended to retire after his second term as was the custom, but when the president of the state senate, Levi H. Greenwood, considered running for lieutenant governor, Coolidge decided to run again for the Senate in the hopes of being elected as its presiding officer.", "Although Greenwood later decided to run for reelection to the Senate, he was defeated primarily due to his opposition to women's suffrage; Coolidge was in favor of the women's vote, won his re-election, and with Crane's help, assumed the presidency of a closely divided Senate.", "After his election in January 1914, Coolidge delivered a published and frequently quoted speech entitled ''Have Faith in Massachusetts'', which summarized his philosophy of government.Coolidge's speech was well received, and he attracted some admirers on its account; towards the end of the term, many of them were proposing his name for nomination to lieutenant governor.", "After winning reelection to the Senate by an increased margin in the 1914 elections, Coolidge was reelected unanimously to be President of the Senate.", "Coolidge's supporters, led by fellow Amherst alumnus Frank Stearns, encouraged him again to run for lieutenant governor.", "Stearns, an executive with the Boston department store R. H. Stearns, became another key ally, and began a publicity campaign on Coolidge's behalf before he announced his candidacy at the end of the 1915 legislative session." ], [ "Lieutenant Governor and Governor of Massachusetts (1916−1921)", "Coolidge entered the primary election for lieutenant governor and was nominated to run alongside gubernatorial candidate Samuel W. McCall.", "Coolidge was the leading vote-getter in the Republican primary, and balanced the Republican ticket by adding a western presence to McCall's eastern base of support.", "McCall and Coolidge won the 1915 election to their respective one-year terms, with Coolidge defeating his opponent by more than 50,000 votes.In Massachusetts, the lieutenant governor does not preside over the state Senate, as is the case in many other states; nevertheless, as lieutenant governor, Coolidge was a deputy governor functioning as an administrative inspector and was a member of the governor's council.", "He was also chairman of the finance committee and the pardons committee.", "As a full-time elected official, Coolidge discontinued his law practice in 1916, though his family continued to live in Northampton.", "McCall and Coolidge were both reelected in 1916 and again in 1917.When McCall decided that he would not stand for a fourth term, Coolidge announced his intention to run for governor.===1918 election===Coolidge was unopposed for the Republican nomination for Governor of Massachusetts in 1918.He and his running mate, Channing Cox, a Boston lawyer and Speaker of the Massachusetts House of Representatives, ran on the previous administration's record: fiscal conservatism, a vague opposition to Prohibition, support for women's suffrage, and support for American involvement in World War I.", "The issue of the war proved divisive, especially among Irish and German Americans.", "Coolidge was elected by a margin of 16,773 votes over his opponent, Richard H. Long, in the smallest margin of victory of any of his statewide campaigns.===Boston police strike===Coolidge inspects militia in Boston police strikeIn 1919, in reaction to a plan of the policemen of the Boston Police Department to register with a union, Police Commissioner Edwin U. Curtis announced that such an act would not be tolerated.", "In August of that year, the American Federation of Labor issued a charter to the Boston Police Union.", "Curtis declared the union's leaders were guilty of insubordination and would be relieved of duty, but indicated he would cancel their suspension if the union was dissolved by September 4.The mayor of Boston, Andrew Peters, convinced Curtis to delay his action for a few days, but with no results, and Curtis suspended the union leaders on September 8.The following day, about three-quarters of the policemen in Boston went on strike.", "Coolidge, tacitly but fully in support of Curtis' position, closely monitored the situation but initially deferred to the local authorities.", "He anticipated that only a resulting measure of lawlessness could sufficiently prompt the public to understand and appreciate the controlling principlethat a policeman does not strike.", "That night and the next, there was sporadic violence and rioting in the unruly city.", "Peters, concerned about sympathy strikes by the firemen and others, called up some units of the Massachusetts National Guard stationed in the Boston area pursuant to an old and obscure legal authority, and relieved Curtis of duty.", "\"Your assertion that the Commissioner was wrong cannot justify the wrong of leaving the city unguarded.", "That furnished the opportunity; the criminal element furnished the action.", "There is no right to strike against the public safety by anyone, anywhere, any time.", "...", "I am equally determined to defend the sovereignty of Massachusetts and to maintain the authority and jurisdiction over her public officers where it has been placed by the Constitution and laws of her people.\"", "\"Telegram from Governor Calvin Coolidge to Samuel Gompers\", September 14, 1919Coolidge, sensing the severity of circumstances were then in need of his intervention, conferred with Crane's operative, William Butler, and then acted.", "He called up more units of the National Guard, restored Curtis to office, and took personal control of the police force.", "Curtis proclaimed that all of the strikers were fired from their jobs, and Coolidge called for a new police force to be recruited.That night Coolidge received a telegram from AFL leader Samuel Gompers.", "\"Whatever disorder has occurred\", Gompers wrote, \"is due to Curtis's order in which the right of the policemen has been denied…\" Coolidge publicly answered Gompers's telegram, denying any justification whatsoever for the strikeand his response launched him into the national consciousness.", "Newspapers across the nation picked up on Coolidge's statement and he became the newest hero to opponents of the strike.", "Amid of the First Red Scare, many Americans were terrified of the spread of communist revolutions, like those that had taken place in Russia, Hungary, and Germany.", "While Coolidge had lost some friends among organized labor, conservatives across the nation had seen a rising star.", "Although he usually acted with deliberation, the Boston police strike gave him a national reputation as a decisive leader, and as a strict enforcer of law and order.===1919 election===Coolidge and Cox were renominated for their respective offices in 1919.By this time Coolidge's supporters (especially Stearns) had publicized his actions in the Police Strike around the state and the nation and some of Coolidge's speeches were published in book form.", "He faced the same opponent as in 1918, Richard Long, but this time Coolidge defeated him by 125,101 votes, more than seven times his margin of victory from a year earlier.", "His actions in the police strike, combined with the massive electoral victory, led to suggestions that Coolidge run for president in 1920.===Legislation and vetoes as governor===By the time Coolidge was inaugurated on January 2, 1919, the First World War had ended, and Coolidge pushed the legislature to give a $100 bonus () to Massachusetts veterans.", "He also signed a bill reducing the work week for women and children from fifty-four hours to forty-eight, saying, \"We must humanize the industry, or the system will break down.\"", "He signed into law a budget that kept the tax rates the same, while trimming $4 million from expenditures, thus allowing the state to retire some of its debt.Coolidge also wielded the veto pen as governor.", "His most publicized veto prevented an increase in legislators' pay by 50%.", "Although he was personally opposed to Prohibition, he vetoed a bill in May 1920 that would have allowed the sale of beer or wine of 2.75% alcohol or less, in Massachusetts in violation of the Eighteenth Amendment to the United States Constitution.", "\"Opinions and instructions do not outmatch the Constitution,\" he said in his veto message.", "\"Against it, they are void.\"" ], [ "Vice presidency (1921–1923)", "===1920 election===At the 1920 Republican National Convention, most of the delegates were selected by state party caucuses, not primaries.", "As such, the field was divided among many local favorites.", "Coolidge was one such candidate, and while he placed as high as sixth in the voting, the powerful party bosses running the convention, primarily the party's U.S.", "Senators, never considered him seriously.", "After ten ballots, the bosses and then the delegates settled on Senator Warren G. Harding of Ohio as their nominee for president.", "When the time came to select a vice presidential nominee, the bosses also made and announced their decision on whom they wantedSen.", "Irvine Lenroot of Wisconsinand then prematurely departed after his name was put forth, relying on the rank and file to confirm their decision.", "A delegate from Oregon, Wallace McCamant, having read ''Have Faith in Massachusetts'', proposed Coolidge for vice president instead.", "The suggestion caught on quickly with the masses starving for an act of independence from the absent bosses, and Coolidge was unexpectedly nominated.The Democrats nominated another Ohioan, James M. Cox, for president and the Assistant Secretary of the Navy, Franklin D. Roosevelt, for vice president.", "The question of the United States joining the League of Nations was a major issue in the campaign, as was the unfinished legacy of Progressivism.", "Harding ran a \"front-porch\" campaign from his home in Marion, Ohio, but Coolidge took to the campaign trail in the Upper South, New York, and New Englandhis audiences carefully limited to those familiar with Coolidge and those placing a premium upon concise and short speeches.", "On November 2, 1920, Harding and Coolidge were victorious in a landslide, winning more than 60 percent of the popular vote, including every state outside the South.", "They also won in Tennessee, the first time a Republican ticket had won a Southern state since Reconstruction.===\"Silent Cal\"===President Harding and Vice President Coolidge with their wivesThe U.S. vice-presidency did not carry many official duties, but Coolidge was invited by President Harding to attend cabinet meetings, making him the first vice president to do so.", "He gave a number of unremarkable speeches around the country.As vice president, Coolidge and his vivacious wife Grace were invited to quite a few parties, where the legend of \"Silent Cal\" was born.", "It is from this time that most of the jokes and anecdotes involving Coolidge originate, such as Coolidge being \"silent in five languages\".", "Although Coolidge was known to be a skilled and effective public speaker, in private he was a man of few words and was commonly referred to as \"Silent Cal\".", "An apocryphal story has it that a person seated next to him at a dinner said to him, \"I made a bet today that I could get more than two words out of you.\"", "He replied, \"You lose.\"", "However, on April 22, 1924, Coolidge himself said that the \"You lose\" quotation never occurred.", "The story about it was related by Frank B. Noyes, President of the Associated Press, to their membership at their annual luncheon at the Waldorf Astoria Hotel, when toasting and introducing Coolidge, who was the invited speaker.", "After the introduction and before his prepared remarks, Coolidge said to the membership, \"Your President referring to Noyes has given you a perfect example of one of those rumors now current in Washington which is without any foundation.", "\"Coolidge often seemed uncomfortable among fashionable Washington society; when asked why he continued to attend so many of their dinner parties, he replied, \"Got to eat somewhere.\"", "Alice Roosevelt Longworth, a leading Republican wit, underscored Coolidge's silence and his dour personality: \"When he wished he were elsewhere, he pursed his lips, folded his arms, and said nothing.", "He looked then precisely as though he had been weaned on a pickle.\"", "Coolidge and his wife, Grace, who was a great baseball fan, once attended a Washington Senators game and sat through all nine innings without saying a word, except once when he asked her the time.As president, Coolidge's reputation as a quiet man continued.", "\"The words of a President have an enormous weight,\" he would later write, \"and ought not to be used indiscriminately.\"", "Coolidge was aware of his stiff reputation; indeed, he cultivated it.", "\"I think the American people want a solemn ass as a President,\" he once told Ethel Barrymore, \"and I think I will go along with them.\"", "Some historians suggest that Coolidge's image was created deliberately as a campaign tactic, while others believe his withdrawn and quiet behavior to be natural, deepening after the death of his son in 1924.Dorothy Parker, upon learning that Coolidge had died, reportedly remarked, \"How can they tell?\"" ], [ "Presidency (1923–1929)", "On August 2, 1923, President Harding died unexpectedly from a heart attack in San Francisco while on a speaking tour of the western United States.", "Vice President Coolidge was in Vermont visiting his family home, which had neither electricity nor a telephone, when he received word by messenger of Harding's death.", "Coolidge dressed, said a prayer, and came downstairs to greet the reporters who had assembled.", "His father, a notary public and justice of the peace, administered the oath of office in the family's parlor by the light of a kerosene lamp at 2:47 a.m. on August 3, 1923, whereupon the new President of the United States returned to bed.Coolidge returned to Washington the next day, and was sworn in again by Justice Adolph A. Hoehling Jr. of the Supreme Court of the District of Columbia, to forestall any questions about the authority of a state official to administer a federal oath.", "This second oath-taking remained a secret until it was revealed by Harry M. Daugherty in 1932, and confirmed by Hoehling.", "When Hoehling confirmed Daugherty's story, he indicated that Daugherty, then serving as United States Attorney General, asked him to administer the oath without fanfare at the Willard Hotel.", "According to Hoehling, he did not question Daugherty's reason for requesting a second oath-taking but assumed it was to resolve any doubt about whether the first swearing-in was valid.President Coolidge signing appropriation bills for the Veterans Bureau, June 1924The nation initially did not know what to make of Coolidge, who had maintained a low profile in the Harding administration; many had even expected him to be replaced on the ballot in 1924.Coolidge believed that those of Harding's men under suspicion were entitled to every presumption of innocence, taking a methodical approach to the scandals, principally the Teapot Dome scandal, while others clamored for rapid punishment of those they presumed guilty.", "Coolidge thought the Senate investigations of the scandals would suffice; this was affirmed by the resulting resignations of those involved.", "He personally intervened in demanding the resignation of Attorney General Harry M. Daugherty after he refused to cooperate with the congressional probe.", "He then set about to confirm that no loose ends remained in the administration, arranging for a full briefing on the wrongdoing.", "Harry A. Slattery reviewed the facts with him, Harlan F. Stone analyzed the legal aspects for him and Senator William E. Borah assessed and presented the political factors.Coolidge addressed Congress when it reconvened on December 6, 1923, giving a speech that supported many of Harding's policies, including Harding's formal budgeting process, the enforcement of immigration restrictions and arbitration of coal strikes ongoing in Pennsylvania.", "The address to Congress was the first presidential speech to be broadcast over the radio.", "The Washington Naval Treaty was proclaimed just one month into Coolidge's term, and was generally well received in the country.", "In May 1924, the World War I veterans' World War Adjusted Compensation Act or \"Bonus Bill\" was passed over his veto.", "Coolidge signed the Immigration Act later that year, which was aimed at restricting southern and eastern European immigration, but appended a signing statement expressing his unhappiness with the bill's specific exclusion of Japanese immigrants.", "Just before the Republican Convention began, Coolidge signed into law the Revenue Act of 1924, which reduced the top marginal tax rate from 58 percent to 46 percent, as well as personal income tax rates across the board, increased the estate tax and bolstered it with a new gift tax.On June 2, 1924, Coolidge signed the act granting citizenship to all Native Americans born in the United States.", "By that time, two-thirds of them were already citizens, having gained it through marriage, military service (veterans of World War I were granted citizenship in 1919), or the land allotments that had earlier taken place.===1924 election===1924 electoral vote resultsThe Republican Convention was held from June 10 to 12, 1924, in Cleveland, Ohio; Coolidge was nominated on the first ballot.", "The convention nominated Frank Lowden of Illinois for vice president on the second ballot, but he declined; former Brigadier General Charles G. Dawes was nominated on the third ballot and accepted.The Democrats held their convention the next month in New York City.", "The convention soon deadlocked, and after 103 ballots, the delegates finally agreed on a compromise candidate, John W. Davis, with Charles W. Bryan nominated for vice president.", "The Democrats' hopes were buoyed when Robert M. La Follette, a Republican senator from Wisconsin, split from the GOP to form a new Progressive Party.", "Many believed that the split in the Republican Party, like the one in 1912, would allow a Democrat to win the presidency.After the conventions and the death of his younger son Calvin, Coolidge became withdrawn; he later said that \"when he the son died, the power and glory of the Presidency went with him.\"", "Even as he mourned, Coolidge ran his standard campaign, not mentioning his opponents by name or maligning them, and delivering speeches on his theory of government, including several that were broadcast over the radio.", "It was the most subdued campaign since 1896, partly because of Coolidge's grief, but also because of his naturally non-confrontational style.", "The other candidates campaigned in a more modern fashion, but despite the split in the Republican party, the results were similar to those of 1920.Coolidge and Dawes won every state outside the South except Wisconsin, La Follette's home state.", "Coolidge won the election with 382 electoral votes and the popular vote by 2.5 million over his opponents' combined total.===Industry and trade===\"It is probable that a press which maintains an intimate touch with the business currents of the nation is likely to be more reliable than it would be if it were a stranger to these influences.", "After all, '''the chief business of the American people is business'''.", "They are profoundly concerned with buying, selling, investing and prospering in the world.\"", "\"President Calvin Coolidge's address to the American Society of Newspaper Editors\", Washington D.C., January 25, 1925During Coolidge's presidency, the United States experienced a period of rapid economic growth known as the \"Roaring Twenties\".", "He left the administration's industrial policy in the hands of his activist Secretary of Commerce, Herbert Hoover, who energetically used government auspices to promote business efficiency and develop airlines and radio.", "Coolidge disdained regulation and demonstrated this by appointing commissioners to the Federal Trade Commission and the Interstate Commerce Commission who did little to restrict the activities of businesses under their jurisdiction.", "The regulatory state under Coolidge was, as one biographer described it, \"thin to the point of invisibility\".Historian Robert Sobel offers some context of Coolidge's ''laissez-faire'' ideology, based on the prevailing understanding of federalism during his presidency: \"As Governor of Massachusetts, Coolidge supported wages and hours legislation, opposed child labor, imposed economic controls during World War I, favored safety measures in factories, and even worker representation on corporate boards.", "Did he support these measures while president?", "No, because in the 1920s, such matters were considered the responsibilities of state and local governments.\"", "However, Coolidge did sign the Radio Act of 1927 into law that established the Federal Radio Commission (1927–1934), the equal-time rule for radio broadcasters in the United States, and restricted radio broadcasting licenses to stations that demonstrated that they served \"the public interest, convenience, or necessity\".===Taxation and government spending===Coolidge adopted the taxation policies of his Secretary of the Treasury, Andrew Mellon, who advocated \"scientific taxation\"the notion that lowering taxes will increase, rather than decrease, government receipts.", "Congress agreed, and tax rates were reduced in Coolidge's term.", "In addition to federal tax cuts, Coolidge proposed reductions in federal expenditures and retiring of the federal debt.", "Coolidge's ideas were shared by the Republicans in Congress, and in 1924, Congress passed the Revenue Act of 1924, which reduced income tax rates and eliminated all income taxation for some two million people.", "They reduced taxes again by passing the Revenue Acts of 1926 and 1928, all the while continuing to keep spending down so as to reduce the overall federal debt.", "By 1927, only the wealthiest 2% of taxpayers paid any federal income tax.", "Federal spending remained flat during Coolidge's administration, allowing one-fourth of the federal debt to be retired in total.", "State and local governments saw considerable growth, however, surpassing the federal budget in 1927.By 1929, after Coolidge's series of tax rate reductions had cut the tax rate to 24 percent on those making over $100,000, the federal government collected more than a billion dollars in income taxes, of which 65 percent was collected from those making over $100,000.In 1921, when the tax rate on people making over $100,000 a year was 73 percent, the federal government collected a little over $700 million in income taxes, of which 30 percent was paid by those making over $100,000.===Opposition to farm subsidies===Coolidge with his vice president, Charles G. DawesPerhaps the most contentious issue of Coolidge's presidency was relief for farmers.", "Some in Congress proposed a bill designed to fight falling agricultural prices by allowing the federal government to purchase crops to sell abroad at lower prices.", "Agriculture Secretary Henry C. Wallace and other administration officials favored the bill when it was introduced in 1924, but rising prices convinced many in Congress that the bill was unnecessary, and it was defeated just before the elections that year.", "In 1926, with farm prices falling once more, Senator Charles L. McNary and Representative Gilbert N. Haugenboth Republicansproposed the McNary–Haugen Farm Relief Bill.", "The bill proposed a federal farm board that would purchase surplus production in high-yield years and hold it (when feasible) for later sale or sell it abroad.", "Coolidge opposed McNary-Haugen, declaring that agriculture must stand \"on an independent business basis\", and said that \"government control cannot be divorced from political control.\"", "Instead of manipulating prices, he favored instead Herbert Hoover's proposal to increase profitability by modernizing agriculture.", "Secretary Mellon wrote a letter denouncing the McNary-Haugen measure as unsound and likely to cause inflation, and it was defeated.After McNary-Haugen's defeat, Coolidge supported a less radical measure, the Curtis-Crisp Act, which would have created a federal board to lend money to farm co-operatives in times of surplus; the bill did not pass.", "In February 1927, Congress took up the McNary-Haugen bill again, this time narrowly passing it, and Coolidge vetoed it.", "In his veto message, he expressed the belief that the bill would do nothing to help farmers, benefiting only exporters and expanding the federal bureaucracy.", "Congress did not override the veto, but it passed the bill again in May 1928 by an increased majority; again, Coolidge vetoed it.", "\"Farmers never have made much money,\" said Coolidge, the Vermont farmer's son.", "\"I do not believe we can do much about it.", "\"===Flood control===Coolidge has often been criticized for his actions during the Great Mississippi Flood of 1927, the worst natural disaster to hit the Gulf Coast until Hurricane Katrina in 2005.Although he did eventually name Secretary Hoover to a commission in charge of flood relief, scholars argue that Coolidge overall showed a lack of interest in federal flood control.", "Coolidge did not believe that personally visiting the region after the floods would accomplish anything, and that it would be seen as mere political grandstanding.", "He also did not want to incur the federal spending that flood control would require; he believed property owners should bear much of the cost.", "On the other hand, Congress wanted a bill that would place the federal government completely in charge of flood mitigation.", "When Congress passed a compromise measure in 1928, Coolidge declined to take credit for it and signed the bill in private on May 15.===Civil rights===Osage men with Coolidge after he signed the bill granting Native Americans U.S. citizenshipAccording to one biographer, Coolidge was \"devoid of racial prejudice\", but rarely took the lead on civil rights.", "Coolidge disliked the Ku Klux Klan and no Klansman is known to have received an appointment from him.", "In the 1924 presidential election his opponents (Robert La Follette and John Davis), and his running mate Charles Dawes, often attacked the Klan but Coolidge avoided the subject.", "During his administration, lynchings of African-Americans decreased and millions of people left the Ku Klux Klan.Coolidge spoke in favor of the civil rights of African Americans, saying in his first State of the Union address that their rights were \"just as sacred as those of any other citizen\" under the U.S. Constitution and that it was a \"public and a private duty to protect those rights.", "\"Coolidge repeatedly called for laws to make lynching a federal crime (it was already a state crime, though not always enforced).", "Congress refused to pass any such legislation.", "On June 2, 1924, Coolidge signed the Indian Citizenship Act, which granted U.S. citizenship to all Native Americans living on reservations.", "(Those off reservations had long been citizens.)", "On June 6, 1924, Coolidge delivered a commencement address at historically black, non-segregated Howard University, in which he thanked and commended African Americans for their rapid advances in education and their contributions to U.S. society over the years, as well as their eagerness to render their services as soldiers in the World War, all while being faced with discrimination and prejudices at home.In a speech in October 1924, Coolidge stressed tolerance of differences as an American value and thanked immigrants for their contributions to U.S. society, saying that they have \"contributed much to making our country what it is.\"", "He stated that although the diversity of peoples was a detrimental source of conflict and tension in Europe, it was peculiar for the United States that it was a \"harmonious\" benefit for the country.", "Coolidge further stated the United States should assist and help immigrants who come to the country and urged immigrants to reject \"race hatreds\" and \"prejudices\".===Foreign policy===Coolidge was neither well versed nor very interested in world affairs.", "His focus was directed mainly at American business, especially pertaining to trade, and \"Maintaining the Status Quo\".", "Although not an isolationist, he was reluctant to enter into European involvements.", "While Coolidge believed strongly in a non-interventionist foreign policy, he did believe that the United States was exceptional.Coolidge considered the 1920 Republican victory as a rejection of the Wilsonian position that the United States should join the League of Nations.", "Coolidge believed the League did not serve American interests.", "However, he spoke in favor of joining the Permanent Court of International Justice (World Court), provided that the nation would not be bound by advisory decisions.", "In 1926, the Senate eventually approved joining the Court (with reservations).", "The League of Nations accepted the reservations, but it suggested some modifications of its own.", "The Senate failed to act and so the United States did not join the World Court.In 1924 the Coolidge administration nominated Charles Dawes to head the multi-national committee that produced the Dawes Plan.", "It set fixed annual amounts for Germany's World War I reparations payments and authorized a large loan, mostly from American banks, to help stabilize and stimulate the German economy.", "Additionally, Coolidge attempted to pursue further curbs on naval strength following the early successes of Harding's Washington Naval Conference by sponsoring the Geneva Naval Conference in 1927, which failed owing to a French and Italian boycott and ultimate failure of Great Britain and the United States to agree on cruiser tonnages.", "As a result, the conference was a failure and Congress eventually authorized for increased American naval spending in 1928.The Kellogg–Briand Pact of 1928, named for Coolidge's Secretary of State, Frank B. Kellogg, and French foreign minister Aristide Briand, was also a key peacekeeping initiative.", "The treaty, ratified in 1929, committed signatoriesthe United States, the United Kingdom, France, Germany, Italy, and Japanto \"renounce war, as an instrument of national policy in their relations with one another\".", "The treaty did not achieve its intended resultthe outlawry of warbut it did provide the founding principle for international law after World War II.", "Coolidge also continued the previous administration's policy of withholding recognition of the Soviet Union.Efforts were made to normalize ties with post-Revolution Mexico.", "Coolidge recognized Mexico's new governments under Álvaro Obregón and Plutarco Elías Calles, and continued American support for the elected Mexican government against the National League for the Defense of Religious Liberty during the Cristero War, lifting the arms embargo on that country; he also appointed Dwight Morrow as Ambassador to Mexico with the successful objective to avoid further American conflict with Mexico.Coolidge's administration would see continuity in the occupation of Nicaragua and Haiti, and an end to the occupation of the Dominican Republic in 1924 as a result of withdrawal agreements finalized during Harding's administration.", "In 1925, Coolidge ordered the withdrawal of Marines stationed in Nicaragua following perceived stability after the 1924 Nicaraguan general election, but redeployed them there in January 1927 following failed attempts to peacefully resolve the rapid deterioration of political stability and avert the ensuing Constitutionalist War; Henry L. Stimson was later sent by Coolidge to mediate a peace deal that would end the civil war and extend American military presence in Nicaragua beyond Coolidge's term in office.To extend an olive branch to Latin American leaders embittered over America's interventionist policies in Central America and the Caribbean, Coolidge led the U.S. delegation to the Sixth International Conference of American States, January 15–17, 1928, in Havana, Cuba, the only international trip Coolidge made during his presidency.", "He would be the last sitting American president to visit Cuba until Barack Obama in 2016.For Canada, Coolidge authorized the St. Lawrence Seaway, a system of locks and canals that would provide large vessels passage between the Atlantic Ocean and the Great Lakes.===Cabinet===Coolidge's cabinet in 1924, outside the White House.Front row, left to right: Harry Stewart New, John W. Weeks, Charles Evans Hughes, Coolidge, Andrew Mellon, Harlan F. Stone, Curtis D. Wilbur.Back row, left to right: James J. Davis, Henry C. Wallace, Herbert Hoover, Hubert Work.|271x271pxAlthough a few of Harding's cabinet appointees were scandal-tarred, Coolidge initially retained all of them, out of an ardent conviction that as successor to a deceased elected president he was obligated to retain Harding's counselors and policies until the next election.", "He kept Harding's able speechwriter Judson T. Welliver; Stuart Crawford replaced Welliver in November 1925.Coolidge appointed C. Bascom Slemp, a Virginia Congressman and experienced federal politician, to work jointly with Edward T. Clark, a Massachusetts Republican organizer whom he retained from his vice-presidential staff, as Secretaries to the President (a position equivalent to the modern White House Chief of Staff).Perhaps the most powerful person in Coolidge's Cabinet was Secretary of the Treasury Andrew Mellon, who controlled the administration's financial policies and was regarded by many, including House Minority Leader John Nance Garner, as more powerful than Coolidge himself.", "Secretary of Commerce Herbert Hoover also held a prominent place in Coolidge's Cabinet, in part because Coolidge found value in Hoover's ability to win positive publicity with his pro-business proposals.", "Secretary of State Charles Evans Hughes directed Coolidge's foreign policy until he resigned in 1925 following Coolidge's re-election.", "He was replaced by Frank B. Kellogg, who had previously served as a senator and as the ambassador to Great Britain.", "Coolidge made two other appointments following his re-election, with William M. Jardine taking the position of Secretary of Agriculture and John G. Sargent becoming Attorney General.", "Coolidge did not have a vice president during his first term, but Charles Dawes became vice president during Coolidge's second term, and Dawes and Coolidge clashed over farm policy and other issues.", "'''OFFICE''''''NAME''''''TERM'''President'''Calvin Coolidge'''1923–1929Vice President''None''1923–1925 '''Charles G. Dawes'''1925–1929Secretary of State'''Charles Evans Hughes'''1923–1925 '''Frank B. Kellogg'''1925–1929Secretary of the Treasury'''Andrew Mellon'''1923–1929Secretary of War'''John W. Weeks'''1923–1925 '''Dwight F. Davis'''1925–1929Attorney General'''Harry M. Daugherty'''1923–1924 '''Harlan F. Stone'''1924–1925 '''John G. Sargent'''1925–1929Postmaster General'''Harry S. New'''1923–1929Secretary of the Navy'''Edwin C. Denby'''1923–1924 '''Curtis D. Wilbur'''1924–1929Secretary of the Interior'''Hubert Work'''1923–1928 '''Roy O.", "West'''1928–1929Secretary of Agriculture'''Henry C. Wallace'''1923–1924 '''Howard M. Gore'''1924–1925 '''William M. Jardine'''1925–1929Secretary of Commerce'''Herbert Hoover'''1923–1928 '''William F. Whiting'''1928–1929Secretary of Labor'''James J. Davis'''1923–1929===Judicial appointments===Coolidge appointed Harlan F. Stone first as attorney general and then as a Supreme Court justice.Coolidge appointed one justice to the Supreme Court of the United States, Harlan F. Stone in 1925.Stone was Coolidge's fellow Amherst alumnus, a Wall Street lawyer and conservative Republican.", "Stone was serving as dean of Columbia Law School when Coolidge appointed him to be attorney general in 1924 to restore the reputation tarnished by Harding's Attorney General, Harry M. Daugherty.", "It does not appear that Coolidge considered appointing anyone other than Stone, although Stone himself had urged Coolidge to appoint Benjamin N. Cardozo.", "Stone proved to be a firm believer in judicial restraint and was regarded as one of the court's three liberal justices who would often vote to uphold New Deal legislation.", "President Franklin D. Roosevelt later appointed Stone to be chief justice.Coolidge nominated 17 judges to the United States Courts of Appeals and 61 judges to the United States district courts.", "He appointed judges to various specialty courts as well, including Genevieve R. Cline, who became the first woman named to the federal judiciary when Coolidge placed her on the United States Customs Court in 1928.Coolidge also signed the Judiciary Act of 1925 into law, allowing the Supreme Court more discretion over its workload.===1928 election===In the summer of 1927, Coolidge vacationed in the Black Hills of South Dakota.", "While on vacation, Coolidge surprisingly issued a terse statement that he would not seek a second full term as president: \"I do not choose to run for President in 1928.\"", "After allowing the reporters to take that in, Coolidge elaborated.", "\"If I take another term, I will be in the White House till 1933 … Ten years in Washington is longer than any other man has had ittoo long!\"", "In his memoirs, Coolidge explained his decision not to run: \"The Presidential office takes a heavy toll of those who occupy it and those who are dear to them.", "While we should not refuse to spend and be spent in the service of our country, it is hazardous to attempt what we feel is beyond our strength to accomplish.\"", "After leaving office, he and Grace returned to Northampton, where he wrote his memoirs.", "The Republicans retained the White House in 1928 with a landslide by Herbert Hoover.", "Coolidge had been reluctant to endorse Hoover as his successor; on one occasion he remarked that \"for six years that man has given me unsolicited adviceall of it bad.\"", "Even so, Coolidge had no desire to split the party by publicly opposing the nomination of the popular commerce secretary." ], [ "Post-presidency (1929–1933)", "Coolidge receiving grapefruit at the Florida Orange Festival in 1930After his presidency, Coolidge retired to a spacious home in Northampton, \"The Beeches\".", "He kept a Hacker runabout boat on the Connecticut River and was often observed on the water by local boating enthusiasts.", "During this period, he also served as chairman of the Non-Partisan Railroad Commission, an entity created by several banks and corporations to survey the country's long-term transportation needs and make recommendations for improvements.", "He was an honorary president of the American Foundation for the Blind, a director of New York Life Insurance Company, president of the American Antiquarian Society, and a trustee of Amherst College.Coolidge published his autobiography in 1929 and wrote a syndicated newspaper column, \"Calvin Coolidge Says\", from 1930 to 1931.Faced with a Democratic landslide in the 1932 presidential election, some Republicans spoke of rejecting Hoover as their party's nominee, and instead drafting Coolidge to run.", "Coolidge made it clear that he was not interested in running again, and that he would publicly repudiate any effort to draft him.", "Hoover was renominated, and Coolidge made several radio addresses in support of him.", "Hoover then lost the general election to Coolidge's 1920 vice presidential Democratic opponent Franklin D. Roosevelt in a landslide." ], [ "Death", "Coolidge died suddenly from coronary thrombosis at \"The Beeches\" on January 5, 1933, at 12:45 p.m., aged 60.Shortly before his death, Coolidge confided to an old friend: \"I feel I no longer fit in with these times.\"", "Coolidge is buried in Plymouth Notch Cemetery, Plymouth Notch, Vermont.", "The nearby family home is maintained as one of the original buildings on the Calvin Coolidge Homestead District site.", "The State of Vermont dedicated a new visitors' center nearby to mark Coolidge's 100th birthday on July 4, 1972." ], [ "Radio, film, and commemorations", "Despite his reputation as a quiet and even reclusive politician, Coolidge made use of the new medium of radio and made radio history several times while president.", "He made himself available to reporters, giving 520 press conferences, meeting with reporters more regularly than any president before or since.", "Coolidge's second inauguration was the first presidential inauguration broadcast on radio.", "On December 6, 1923, his speech to Congress was broadcast on radio, the first presidential radio address.", "Coolidge signed the Radio Act of 1927, which assigned regulation of radio to the newly created Federal Radio Commission.", "On August 11, 1924, Theodore W. Case, using the Phonofilm sound-on-film process he developed for Lee de Forest, filmed Coolidge on the White House lawn, making \"Silent Cal\" the first president to appear in a sound film.", "The title of the DeForest film was ''President Coolidge, Taken on the White House Grounds''.", "When Charles Lindbergh arrived in Washington on a U.S. Navy ship after his celebrated 1927 trans-Atlantic flight, President Coolidge welcomed him back to the U.S. and presented him with the Medal of Honor; the event was captured on film.File:Ccoolidge.jpeg|Official presidential portrait of Coolidge, 1932File:Sesquicentennial american independence half dollar commemorative obverse.jpg|The Sesquicentennial of American Independence Half Dollar, minted in 1926File:Calvin Coolidge 1938 Issue-$5.jpg|Coolidge on a 1938 postage stampFile:Coolidge with press.jpg|Coolidge with reporters and cameramen, 1924File:Calvin Coolidge video montage.ogg|Collection of video clips of President Coolidge" ], [ "See also", "* * Coolidge, Arizona* Coolidge Dam* List of things named after Calvin Coolidge* Presidency of Calvin Coolidge" ], [ "Notes" ], [ "References" ], [ "Works cited", "===About Coolidge and his era===* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ===By Coolidge===* * * *" ], [ "Further reading", "* * * * * Postell, Joseph W. \"Roaring Against Progressivism: The Principled Conservatism of Calvin Coolidge,\" in Joseph W. Postell and Johnathan O'Neill, eds.", "''Toward an American Conservatism: Constitutional Conservatism during the Progressive Era'' (2013) pp. 181–208.", "* Russell, Francis.", "\"Coolidge and the Boston Police Strike.\"", "''Antioch Review'' 16#4 (1956), pp.", "403–15.online* Tacoma, Thomas J.", "''The Political Thought of Calvin Coolidge: Burkean Americanist'' (Lexington Books, 2020).", "* Tacoma, Thomas.", "\"Calvin Coolidge and the Great Depression: A New Assessment.\"", "''Independent Review'' 24.3 (2019): 361–380.online* Zibel, Howard J.", "\"The Role of Calvin Coolidge in the Boston Police Strike of 1919,\" ''Industrial and Labor Relations Forum'' 6, no.", "3 (November 1969): 299–318===Primary sources===* *" ], [ "External links", "* White House biography* * Calvin Coolidge Presidential Library & Museum* Calvin Coolidge Presidential Foundation* Text of a number of Coolidge speeches, Miller Center of Public Affairs* * Calvin Coolidge: A Resource Guide, Library of Congress* * * '' President Coolidge, Taken on the White House Ground'', the first presidential film with sound recording* * \"Life Portrait of Calvin Coolidge\", from C-SPAN's ''American Presidents: Life Portraits'', September 27, 1999* Calvin Coolidge Personal Manuscripts* * *" ] ]
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[ [ "Convention on Biological Diversity" ], [ "Introduction", "The '''Convention on Biological Diversity''' ('''CBD'''), known informally as the '''Biodiversity Convention''', is a multilateral treaty.", "The Convention has three main goals: the conservation of biological diversity (or biodiversity); the sustainable use of its components; and the fair and equitable sharing of benefits arising from genetic resources.", "Its objective is to develop national strategies for the conservation and sustainable use of biological diversity, and it is often seen as the key document regarding sustainable development.The Convention was opened for signature at the Earth Summit in Rio de Janeiro on 5 June 1992 and entered into force on 29 December 1993.The United States is the only UN member state which has not ratified the Convention.", "It has two supplementary agreements, the Cartagena Protocol and Nagoya Protocol.The Cartagena Protocol on Biosafety to the Convention on Biological Diversity is an international treaty governing the movements of living modified organisms (LMOs) resulting from modern biotechnology from one country to another.", "It was adopted on 29 January 2000 as a supplementary agreement to the CBD and entered into force on 11 September 2003.The Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization (ABS) to the Convention on Biological Diversity is another supplementary agreement to the CBD.", "It provides a transparent legal framework for the effective implementation of one of the three objectives of the CBD: the fair and equitable sharing of benefits arising out of the utilization of genetic resources.", "The Nagoya Protocol was adopted on 29 October 2010 in Nagoya, Japan, and entered into force on 12 October 2014.2010 was also the International Year of Biodiversity, and the Secretariat of the CBD was its focal point.", "Following a recommendation of CBD signatories at Nagoya, the UN declared 2011 to 2020 as the United Nations Decade on Biodiversity in December 2010.The Convention's ''Strategic Plan for Biodiversity 2011-2020'', created in 2010, include the Aichi Biodiversity Targets.The meetings of the Parties to the Convention are known as Conferences of the Parties (COP), with the first one (COP 1) held in Nassau, Bahamas, in 1994 and the most recent one (COP 15) in 2021/2022 in Kunming, China and Montreal, Canada.In the area of marine and coastal biodiversity CBD's focus at present is to identify Ecologically or Biologically Significant Marine Areas (EBSAs) in specific ocean locations based on scientific criteria.", "The aim is to create an international legally binding instrument (ILBI) involving area-based planning and decision-making under UNCLOS to support the conservation and sustainable use of marine biological diversity beyond areas of national jurisdiction (BBNJ)." ], [ "Origin and scope", "The notion of an international convention on biodiversity was conceived at a United Nations Environment Programme (UNEP) Ad Hoc Working Group of Experts on Biological Diversity in November 1988.The subsequent year, the Ad Hoc Working Group of Technical and Legal Experts was established for the drafting of a legal text which addressed the conservation and sustainable use of biological diversity, as well as the sharing of benefits arising from their utilization with sovereign states and local communities.In 1991, an intergovernmental negotiating committee was established, tasked with finalizing the Convention's text.A Conference for the Adoption of the Agreed Text of the Convention on Biological Diversity was held in Nairobi, Kenya, in 1992, and its conclusions were distilled in the Nairobi Final Act.", "The Convention's text was opened for signature on 5 June 1992 at the United Nations Conference on Environment and Development (the Rio \"Earth Summit\").", "By its closing date, 4 June 1993, the Convention had received 168 signatures.", "It entered into force on 29 December 1993.The Convention recognized for the first time in international law that the conservation of biodiversity is \"a common concern of humankind\" and is an integral part of the development process.", "The agreement covers all ecosystems, species, and genetic resources.", "It links traditional conservation efforts to the economic goal of using biological resources sustainably.", "It sets principles for the fair and equitable sharing of the benefits arising from the use of genetic resources, notably those destined for commercial use.", "It also covers the rapidly expanding field of biotechnology through its Cartagena Protocol on Biosafety, addressing technology development and transfer, benefit-sharing and biosafety issues.", "Importantly, the Convention is legally binding; countries that join it ('Parties') are obliged to implement its provisions.The Convention reminds decision-makers that natural resources are not infinite and sets out a philosophy of sustainable use.", "While past conservation efforts were aimed at protecting particular species and habitats, the Convention recognizes that ecosystems, species and genes must be used for the benefit of humans.", "However, this should be done in a way and at a rate that does not lead to the long-term decline of biological diversity.The Convention also offers decision-makers guidance based on the precautionary principle which demands that where there is a threat of significant reduction or loss of biological diversity, lack of full scientific certainty should not be used as a reason for postponing measures to avoid or minimize such a threat.", "The Convention acknowledges that substantial investments are required to conserve biological diversity.", "It argues, however, that conservation will bring us significant environmental, economic and social benefits in return.The Convention on Biological Diversity of 2010 banned some forms of geoengineering." ], [ "Executive secretary", "As of 1 December 2019, the acting executive secretary is Elizabeth Maruma Mrema.The previous executive secretaries were::pl:Cristiana Pașca Palmer (2017–2019), Braulio Ferreira de Souza Dias (2012–2017), Ahmed Djoghlaf (2006–2012), Hamdallah Zedan (1998–2005), Calestous Juma (1995–1998), and Angela Cropper (1993–1995)." ], [ "Issues", "Some of the many issues dealt with under the Convention include:* Measures the incentives for the conservation and sustainable use of biological diversity.", "* Regulated access to genetic resources and traditional knowledge, including Prior Informed Consent of the party providing resources.", "* Sharing, in a fair and equitable way, the results of research and development and the benefits arising from the commercial and other utilization of genetic resources with the Contracting Party providing such resources (governments and/or local communities that provided the traditional knowledge or biodiversity resources utilized).", "* Access to and transfer of technology, including biotechnology, to the governments and/or local communities that provided traditional knowledge and/or biodiversity resources.", "* Technical and scientific cooperation.", "* Coordination of a global directory of taxonomic expertise (Global Taxonomy Initiative).", "* Impact assessment.", "* Education and public awareness.", "* Provision of financial resources.", "* National reporting on efforts to implement treaty commitments." ], [ "International bodies established", "===Conference of the Parties (COP)===The Convention's governing body is the Conference of the Parties (COP), consisting of all governments (and regional economic integration organizations) that have ratified the treaty.", "This ultimate authority reviews progress under the Convention, identifies new priorities, and sets work plans for members.", "The COP can also make amendments to the Convention, create expert advisory bodies, review progress reports by member nations, and collaborate with other international organizations and agreements.The Conference of the Parties uses expertise and support from several other bodies that are established by the Convention.", "In addition to committees or mechanisms established on an ad hoc basis, the main organs are:===CBD Secretariat===The CBD Secretariat, based in Montreal, Quebec, Canada, operates under UNEP, the United Nations Environment Programme.", "Its main functions are to organize meetings, draft documents, assist member governments in the implementation of the programme of work, coordinate with other international organizations, and collect and disseminate information.===Subsidiary Body for Scientific, Technical and Technological Advice (SBSTTA)===The SBSTTA is a committee composed of experts from member governments competent in relevant fields.", "It plays a key role in making recommendations to the COP on scientific and technical issues.", "It provides assessments of the status of biological diversity and of various measures taken in accordance with Convention, and also gives recommendations to the Conference of the Parties, which may be endorsed in whole, in part or in modified form by the COPs.", "SBSTTA had met 23 times, with a 24th meeting taking place in Geneva, Switzerland in 2022.===Subsidiary Body on Implementation (SBI)===In 2014, the Conference of the Parties to the Convention on Biological Diversity established the Subsidiary Body on Implementation (SBI) to replace the Ad Hoc Open-ended Working Group on Review of Implementation of the Convention.", "The four functions and core areas of work of SBI are: (a) review of progress in implementation; (b) strategic actions to enhance implementation; (c) strengthening means of implementation; and (d) operations of the Convention and the Protocols.", "The first meeting of the SBI was held on 2–6 May 2016 and the second meeting was held on 9–13 July 2018, both in Montreal, Canada.", "The third meeting of the SBI will be held in March 2022 in Geneva, Switzerland.", "The Bureau of the Conference of the Parties serves as the Bureau of the SBI.", "The current chair of the SBI is Ms. Charlotta Sörqvist of Sweden." ], [ "Parties", "As of 2016, the Convention has 196 Parties, which includes 195 states and the European Union.", "All UN member states—with the exception of the United States—have ratified the treaty.", "Non-UN member states that have ratified are the Cook Islands, Niue, and the State of Palestine.", "The Holy See and the states with limited recognition are non-Parties.", "The US has signed but not ratified the treaty, because ratification requires a two-thirds majority in the Senate and is blocked by Republican Party senators.The European Union created the Cartagena Protocol (see below) in 2000 to enhance biosafety regulation and propagate the \"precautionary principle\" over the \"sound science principle\" defended by the United States.", "Whereas the impact of the Cartagena Protocol on domestic regulations has been substantial, its impact on international trade law remains uncertain.", "In 2006, the World Trade Organization (WTO) ruled that the European Union had violated international trade law between 1999 and 2003 by imposing a moratorium on the approval of genetically modified organisms (GMO) imports.", "Disappointing the United States, the panel nevertheless \"decided not to decide\" by not invalidating the stringent European biosafety regulations.Implementation by the Parties to the Convention is achieved using two means:===National Biodiversity Strategies and Action Plans (NBSAP)==='''National Biodiversity Strategies and Action Plans''' ('''NBSAP''') are the principal instruments for implementing the Convention at the national level.", "The Convention requires that countries prepare a national biodiversity strategy and to ensure that this strategy is included in planning for activities in all sectors where diversity may be impacted.", "As of early 2012, 173 Parties had developed NBSAPs.The United Kingdom, New Zealand and Tanzania carried out elaborate responses to conserve individual species and specific habitats.", "The United States of America, a signatory who had not yet ratified the treaty by 2010, produced one of the most thorough implementation programs through species recovery programs and other mechanisms long in place in the US for species conservation.Singapore established a detailed ''National Biodiversity Strategy and Action Plan''.", "The ''National Biodiversity Centre'' of Singapore represents Singapore in the Convention for Biological Diversity.===National Reports===In accordance with Article 26 of the Convention, Parties prepare national reports on the status of implementation of the Convention." ], [ "Protocols and plans developed by CBD", "===Cartagena Protocol (2000)===The Cartagena Protocol on Biosafety, also known as the Biosafety Protocol, was adopted in January 2000, after a CBD Open-ended Ad Hoc Working Group on Biosafety had met six times between July 1996 and February 1999.The Working Group submitted a draft text of the Protocol for consideration by Conference of the Parties at its first extraordinary meeting, which was convened for the express purpose of adopting a protocol on biosafety to the Convention on Biological Diversity.", "After a few delays, the Cartagena Protocol was eventually adopted on 29 January 2000.The Biosafety Protocol seeks to protect biological diversity from the potential risks posed by living modified organisms resulting from modern biotechnology.The Biosafety Protocol makes clear that products from new technologies must be based on the precautionary principle and allow developing nations to balance public health against economic benefits.", "It will, for example, let countries ban imports of a genetically modified organism if they feel there is not enough scientific evidence the product is safe and requires exporters to label shipments containing genetically modified commodities such as corn or cotton.The required number of 50 instruments of ratification/accession/approval/acceptance by countries was reached in May 2003.In accordance with the provisions of its Article 37, the Protocol entered into force on 11 September 2003.=== Global Strategy for Plant Conservation (2002) ===In April 2002, the Parties of the UN CBD adopted the recommendations of the Gran Canaria Declaration Calling for a Global Plant Conservation Strategy, and adopted a 16-point plan aiming to slow the rate of plant extinctions around the world by 2010.===Nagoya Protocol (2010)===The Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization to the Convention on Biological Diversity was adopted on 29 October 2010 in Nagoya, Aichi Prefecture, Japan, at the tenth meeting of the Conference of the Parties, and entered into force on 12 October 2014.The protocol is a supplementary agreement to the Convention on Biological Diversity, and provides a transparent legal framework for the effective implementation of one of the three objectives of the CBD: the fair and equitable sharing of benefits arising out of the utilization of genetic resources.", "It thereby contributes to the conservation and sustainable use of biodiversity.===Strategic Plan for Biodiversity 2011-2020===Also at the tenth meeting of the Conference of the Parties, held from 18 to 29 October 2010 in Nagoya, a revised and updated \"Strategic Plan for Biodiversity, 2011-2020\" was agreed and published.", "This document included the \"Aichi Biodiversity Targets\", comprising 20 targets that address each of five strategic goals defined in the plan.", "The strategic plan includes the following strategic goals:* Strategic Goal A: Address the underlying causes of biodiversity loss by mainstreaming biodiversity across government and society* Strategic Goal B: Reduce the direct pressures on biodiversity and promote sustainable use* Strategic Goal C: To improve the status of biodiversity by safeguarding ecosystems, species and genetic diversity* Strategic Goal D: Enhance the benefits to all from biodiversity and ecosystem services* Strategic Goal E: Enhance implementation through participatory planning, knowledge management and capacity buildingUpon the launch of Agenda 2030, CBD released a technical note mapping and identifying synergies between the 17 Sustainable Development Goals (SDGs) and the 20 Aichi Biodiversity Targets.", "This helps to understand the contributions of biodiversity to achieving the SDGs.=== Post-2020 Global Biodiversity Framework ===A new plan, known as the post-2020 Global Biodiversity Framework (GBF) was developed to guide action through 2030.A first draft of this framework was released in July 2021, and its final content was discussed and negotiated as part of the COP 15 meetings.", "Reducing agricultural pollution and sharing the benefits of digital sequence information arose as key points of contention among Parties during development of the framework.", "A final version was adopted by the Convention on 19 December 2022.The framework includes a number of ambitious goals, including a commitment to designate at least 30 percent of global land and sea as protected areas (known as the \"30 by 30\" initiative).=== Marine and coastal biodiversity ===The CBD has a significant focus on marine and coastal biodiversity.", "A series of expert workshops have been held (2018–2022) to identify options for modifying the description of Ecologically or Biologically Significant Marine Areas (EBSAs) and describing new areas.", "These have focused on the North-East, North-West and South-Eastern Atlantic Ocean, Baltic Sea, Caspian Sea, Black Sea, Seas of East Asia, North-West Indian Ocean and Adjacent Gulf Areas, Southern and North-East Indian Ocean, Mediterranean Sea, North and South Pacific, Eastern Tropical and Temperate Pacific, Wider Caribbean and Western Mid-Atlantic.", "The workshop meetings have followed the EBSA process based on internationally agreed scientific criteria.", "This is aimed at creating an international legally binding instrument (ILBI) under UNCLOS to support the conservation and sustainable use of marine biological diversity beyond areas of national jurisdiction (BBNJ).", "The central mechanism is area-based planning and decision-making.", "It integrates EBSAs, Vulnerable Marine Ecosystems (VMEs) and High Seas (Marine Protected Areas) with Blue Growth scenarios.", "There is also linkage with the EU Marine Strategy Framework Directive." ], [ "Criticism", "There have been criticisms against CBD that its implementation has been weakened due to resistance of Western countries to the implementation of pro-South provisions of the Convention.", "CBD is also regarded as a case of a hard treaty gone soft in the implementation trajectory.", "The argument to enforce the treaty as a legally binding multilateral instrument with the Conference of Parties reviewing the infractions and non-compliance is also gaining strength.Although the Convention explicitly states that all forms of life are covered by its provisions, examination of reports and of national biodiversity strategies and action plans submitted by participating countries shows that in practice this is not happening.", "The fifth report of the European Union, for example, makes frequent reference to animals (particularly fish) and plants, but does not mention bacteria, fungi or protists at all.", "The International Society for Fungal Conservation has assessed more than 100 of these CBD documents for their coverage of fungi using defined criteria to place each in one of six categories.", "No documents were assessed as good or adequate, less than 10% as nearly adequate or poor, and the rest as deficient, seriously deficient or totally deficient.Scientists working with biodiversity and medical research are expressing fears that the Nagoya Protocol is counterproductive, and will hamper disease prevention and conservation efforts, and that the threat of imprisonment of scientists will have a chilling effect on research.", "Non-commercial researchers and institutions such as natural history museums fear maintaining biological reference collections and exchanging material between institutions will become difficult, and medical researchers have expressed alarm at plans to expand the protocol to make it illegal to publicly share genetic information, e.g.", "via GenBank.William Yancey Brown, when with the Brookings Institution, suggested that the Convention on Biological Diversity should include the preservation of intact genomes and viable cells for every known species and for new species as they are discovered." ], [ "Meetings of the Parties", "A Conference of the Parties (COP) was held annually for three years after 1994, and thence biennially on even-numbered years.===1994 COP 1===The first ordinary meeting of the Parties to the Convention took place in November and December 1994, in Nassau, Bahamas.===1995 COP 2===The second ordinary meeting of the Parties to the Convention took place in November 1995, in Jakarta, Indonesia.===1996 COP 3===The third ordinary meeting of the Parties to the Convention took place in November 1996, in Buenos Aires, Argentina.===1998 COP 4===The fourth ordinary meeting of the Parties to the Convention took place in May 1998, in Bratislava, Slovakia.===1999 EX-COP 1 (Cartagena)===The First Extraordinary Meeting of the Conference of the Parties took place in February 1999, in Cartagena, Colombia.", "A series of meetings led to the adoption of the Cartagena Protocol on Biosafety in January 2000, effective from 2003.===2000 COP 5===The fifth ordinary meeting of the Parties to the Convention took place in May 2000, in Nairobi, Kenya.===2002 COP 6===The sixth ordinary meeting of the Parties to the Convention took place in April 2002, in The Hague, Netherlands.===2004 COP 7===The seventh ordinary meeting of the Parties to the Convention took place in February 2004, in Kuala Lumpur, Malaysia.===2006 COP 8===The eighth ordinary meeting of the Parties to the Convention took place in March 2006, in Curitiba, Brazil.===2008 COP 9===The ninth ordinary meeting of the Parties to the Convention took place in May 2008, in Bonn, Germany.===2010 COP 10 (Nagoya)===The tenth ordinary meeting of the Parties to the Convention took place in October 2010, in Nagoya, Japan.", "It was at this meeting that the Nagoya Protocol was ratified.2010 was the International Year of Biodiversity and the Secretariat of the CBD was its focal point.", "Following a recommendation of CBD signatories during COP 10 at Nagoya, the UN, on 22 December 2010, declared 2011 to 2020 as the United Nations Decade on Biodiversity.===2012 COP 11===Leading up to the Conference of the Parties (COP 11) meeting on biodiversity in Hyderabad, India, 2012, preparations for a World Wide Views on Biodiversity has begun, involving old and new partners and building on the experiences from the World Wide Views on Global Warming.===2014 COP 12===Under the theme, \"Biodiversity for Sustainable Development\", thousands of representatives of governments, NGOs, indigenous peoples, scientists and the private sector gathered in Pyeongchang, Republic of Korea in October 2014 for the 12th meeting of the Conference of the Parties to the Convention on Biological Diversity (COP 12).From 6–17 October 2014, Parties discussed the implementation of the Strategic Plan for Biodiversity 2011-2020 and its Aichi Biodiversity Targets, which are to be achieved by the end of this decade.", "The results of Global Biodiversity Outlook 4, the flagship assessment report of the CBD informed the discussions.The conference gave a mid-term evaluation to the UN Decade on Biodiversity (2011–2020) initiative, which aims to promote the conservation and sustainable use of nature.", "The meeting achieved a total of 35 decisions, including a decision on \"Mainstreaming gender considerations\", to incorporate gender perspective to the analysis of biodiversity.At the end of the meeting, the meeting adopted the \"Pyeongchang Road Map\", which addresses ways to achieve biodiversity through technology cooperation, funding and strengthening the capacity of developing countries.===2016 COP 13===COP13 Mexico meetingThe thirteenth ordinary meeting of the Parties to the Convention took place between 2 and 17 December 2016 in Cancún, Mexico.===2018 COP 14===The 14th ordinary meeting of the Parties to the Convention took place on 17–29 November 2018, in Sharm El-Sheikh, Egypt.", "The 2018 UN Biodiversity Conference closed on 29 November 2018 with broad international agreement on reversing the global destruction of nature and biodiversity loss threatening all forms of life on Earth.", "Parties adopted the Voluntary Guidelines for the design and effective implementation of ecosystem-based approaches to climate change adaptation and disaster risk reduction.", "Governments also agreed to accelerate action to achieve the Aichi Biodiversity Targets, agreed in 2010, until 2020.Work to achieve these targets would take place at the global, regional, national and subnational levels.===2021/2022 COP 15===COP15 Canada meetingThe 15th meeting of the Parties was originally scheduled to take place in Kunming, China in 2020, but was postponed several times due to the COVID-19 pandemic.", "After the start date was delayed for a third time, the Convention was split into two sessions.", "A mostly online event took place in October 2021, where over 100 nations signed the Kunming declaration on biodiversity.", "The theme of the declaration was \"Ecological Civilization: Building a Shared Future for All Life on Earth\".", "Twenty-one action-oriented draft targets were provisionally agreed in the October meeting, to be further discussed in the second session: an in-person event that was originally scheduled to start in April 2022, but was rescheduled to occur later in 2022.The second part of COP 15 ultimately took place in Montreal, Canada, from 5–17 December 2022.At the meeting, the Parties to the Convention adopted a new action plan, the Kunming-Montreal Global Biodiversity Framework.===2024 COP 16===The 16th meeting of the Parties is scheduled to be held in Colombia in 2024.Originally, Turkey was going to host it but after a series of earthquakes in February 2023 they had to withdraw." ], [ "See also", "* 2010 Biodiversity Indicators Partnership* 2010 Biodiversity Target* 30 by 30* Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPs)* Biodiversity banking* Biological Diversity Act, 2002* Biopiracy* Bioprospecting* Biosphere Reserve* Convention on the Conservation of Migratory Species of Wild Animals* Convention on the International Trade in Endangered Species of Wild Flora and Fauna* Convention on Wetlands of International Importance, especially as Waterfowl Habitat* Ecotourism* Endangered species* Endangered Species Recovery Plan* Environmental agreements* Environmental Modification Convention, another ban on weather modification / climate engineering.", "* Globally Important Agricultural Heritage Systems (GIAHS)* Green Development Initiative (GDI)* Holocene extinction* Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services* International Cooperative Biodiversity Groups* International Organization for Biological Control* International Treaty on Plant Genetic Resources for Food and Agriculture* International Day for Biological Diversity* International Year of Biodiversity* Kunming-Montreal Global Biodiversity Framework* Migratory Bird Treaty Act of 1918* Red Data Book of Singapore* Red Data Book of the Russian Federation* Satoyama* Sustainable forest management* United Nations Convention to Combat Desertification* United Nations Decade on Biodiversity* United Nations Framework Convention on Climate Change* World Conservation Monitoring Centre" ], [ "References", "*" ], [ "Further reading", "* Davis, K. 2008.A CBD manual for botanic gardens English version, Italian version Botanic Gardens Conservation International (BGCI)" ], [ "External links", "* The Convention on Biological Diversity (CBD) website* Text of the Convention from CBD website* Ratifications at depositary* Case studies on the implementation of the Convention from BGCI website with links to relevant articles* Introductory note by Laurence Boisson de Chazournes, procedural history note and audiovisual material on the ''Convention on Biological Diversity'' in the Historic Archives of the United Nations Audiovisual Library of International Law" ] ]
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[ [ "Convention on Fishing and Conservation of the Living Resources of the High Seas" ], [ "Introduction", "The '''Convention on Fishing and Conservation of Living Resources of the High Seas''' is an agreement that was designed to solve through international cooperation the problems involved in the conservation of living resources of the high seas, considering that because of the development of modern technology some of these resources are in danger of being overexploited.", "The convention opened for signature on 29 April 1958 and entered into force on 20 March 1966." ], [ "Participation", "''Parties'' – (39): Australia, Belgium, Bosnia and Herzegovina, Burkina Faso, Cambodia, Colombia, Republic of the Congo, Denmark, Dominican Republic, Fiji, Finland, France, Haiti, Jamaica, Kenya, Lesotho, Madagascar, Malawi, Malaysia, Mauritius, Mexico, Montenegro, Netherlands, Nigeria, Portugal, Senegal, Serbia, Sierra Leone, Solomon Islands, South Africa, Spain, Switzerland, Thailand, Tonga, Trinidad and Tobago, Uganda, United Kingdom, United States, Venezuela.", "''Countries that have signed, but not yet ratified'' – (21): Afghanistan, Argentina, Bolivia, Canada, Costa Rica, Cuba, Ghana, Iceland, Indonesia, Iran, Ireland, Israel, Lebanon, Liberia, Nepal, New Zealand, Pakistan, Panama, Sri Lanka, Tunisia, Uruguay." ], [ "See also", "*Environmental effects of fishing*United Nations Convention on the Law of the Sea*Convention on the High Seas" ], [ "References", "* CIA World Factbook, edition* Indonesian Law #19/1961" ], [ "External links", "* Indonesian Law #19/1961* Convention of the High Seas (1958) * Convention on Fishing and Conservation of Living Resources of the High Seas (1958)" ] ]
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[ [ "Convention on Long-Range Transboundary Air Pollution" ], [ "Introduction", "Map showing Convention on Long-Range Transboundary Air Pollution signatories (green) and ratifications (dark green) as of July 2007The '''Convention on Long-Range Transboundary Air Pollution''', often abbreviated as '''Air Convention''' or '''CLRTAP''', is intended to protect the human environment against air pollution and to gradually reduce and prevent air pollution, including long-range transboundary air pollution.", "It is implemented by the European Monitoring and Evaluation Programme (EMEP), directed by the United Nations Economic Commission for Europe (UNECE).The convention opened for signature on , and entered into force on ." ], [ "Secretariat", "The Convention, which now has 51 Parties, identifies the Executive Secretary of the United Nations Economic Commission for Europe (UNECE) as its secretariat.", "The current parties to the Convention are shown on the map.The Convention is implemented by the European Monitoring and Evaluation Programme (EMEP) (short for ''Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe'').", "Results of the EMEP programme are published on the EMEP website, www.emep.int." ], [ "Procedure", "The aim of the Convention is that Parties shall endeavour to limit and, as far as possible, gradually reduce and prevent air pollution including long-range transboundary air pollution.", "Parties develop policies and strategies to combat the discharge of air pollutants through exchanges of information, consultation, research and monitoring.The Parties meet annually at sessions of the Executive Body to review ongoing work and plan future activities including a workplan for the coming year.", "The three main subsidiary bodies – the Working Group on Effects, the Steering Body to EMEP and the Working Group on Strategies and Review – as well as the Convention's Implementation Committee, report to the Executive Body each year.Currently, the Convention's priority activities include review and possible revision of its most recent protocols, implementation of the Convention and its protocols across the entire UNECE region (with special focus on Eastern Europe, the Caucasus and Central Asia and South-East Europe) and sharing its knowledge and information with other regions of the world." ], [ "Protocols", "Since 1979 the Convention on Long-range Transboundary Air Pollution has addressed some of the major environmental problems of the UNECE region through scientific collaboration and policy negotiation.", "The Convention has been extended by eight protocols that identify specific measures to be taken by Parties to cut their emissions of air pollutants:* Protocol on Long-Term Financing of the Cooperative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (EMEP) (1984)* 1985 Helsinki Protocol on the Reduction of Sulphur Emissions* Nitrogen Oxide Protocol (1988)* Volatile Organic Compounds Protocol (1991)* 1994 Oslo Protocol on Further Reduction of Sulphur Emissions* Protocol on Heavy Metals (1998)* Aarhus Protocol on Persistent Organic Pollutants (1998)* 1999 Gothenburg Protocol to Abate Acidification, Eutrophication and Ground-level Ozone (1999)" ], [ "See also", "* Aarhus Protocol on Persistent Organic Pollutants* Protocol on Heavy Metals* Critical load*International environmental agreements* Gothenburg (Multi-effect) Protocol*1985 Helsinki Protocol on the Reduction of Sulphur Emissions*1994 Oslo Protocol on Further Reduction of Sulphur Emissions*Volatile Organic Compounds Protocol* CIA World Factbook, edition" ], [ "References" ], [ "External links", "* Convention on Long-Range Transboundary Air Pollution* Ratifications, at depositary" ] ]
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[ [ "CITES" ], [ "Introduction", "'''CITES''' (shorter name for the '''Convention on International Trade in Endangered Species of Wild Fauna and Flora''', also known as the '''Washington Convention''') is a multilateral treaty to protect endangered plants and animals from the threats of international trade.", "It was drafted as a result of a resolution adopted in 1963 at a meeting of members of the International Union for Conservation of Nature (IUCN).", "The convention was opened for signature in 1973 and CITES entered into force on 1 July 1975.Its aim is to ensure that international trade (import/export) in specimens of animals and plants included under CITES, does not threaten the survival of the species in the wild.", "This is achieved via a system of permits and certificates.", "CITES affords varying degrees of protection to more than 38,000 species., the Secretary-General of CITES is Ivonne Higuero." ], [ "Background", "CITES is one of the largest and oldest conservation and sustainable use agreements in existence.", "There are three working languages of the Convention (English, French and Spanish) in which all documents are made available.", "Participation is voluntary and countries that have agreed to be bound by the convention are known as Parties.", "Although CITES is legally binding on the Parties, it does not take the place of national laws.", "Rather it provides a framework respected by each Party, which must adopt their own domestic legislation to implement CITES at the national level.Originally, CITES addressed depletion resulting from demand for luxury goods such as furs in Western countries, but with the rising wealth of Asia, particularly in China, the focus changed to products demanded there, particularly those used for luxury goods such as elephant ivory or rhinoceros horn.", "As of 2022, CITES has expanded to include thousands of species previously considered unremarkable and in no danger of extinction such as manta rays or pangolins.===Ratifications===Parties to the treaty.", "Greenland is covered by CITES regulations through Denmark.The text of the convention was finalized at a meeting of representatives of 80 countries in Washington, D.C., United States, on 3 March 1973.It was then open for signature until 31 December 1974.It entered into force after the 10th ratification by a signatory country, on 1 July 1975.Countries that signed the Convention become Parties by ratifying, accepting or approving it.", "By the end of 2003, all signatory countries had become Parties.", "States that were not signatories may become Parties by acceding to the convention.", ", the convention has 184 parties, including 183 states and the European Union.The CITES Convention includes provisions and rules for trade with non-Parties.", "All member states of the United Nations are party to the treaty, with the exception of North Korea, Federated States of Micronesia, Haiti, Kiribati, Marshall Islands, Nauru, South Sudan, East Timor, Turkmenistan, and Tuvalu.", "UN observer the Holy See is also not a member.", "The Faroe Islands, an autonomous region in the Kingdom of Denmark, is also treated as a non-Party to CITES (both the Danish mainland and Greenland are part of CITES).An amendment to the text of the convention, known as the Gaborone Amendment allows regional economic integration organizations (REIO), such as the European Union, to have the status of a member state and to be a Party to the convention.", "The REIO can vote at CITES meetings with the number of votes representing the number of members in the REIO, but it does not have an additional vote.In accordance with Article XVII, paragraph 3, of the CITES Convention, the Gaborone Amendment entered into force on 29 November 2013, 60 days after 54 (two-thirds) of the 80 States that were party to CITES on 30 April 1983 deposited their instrument of acceptance of the amendment.", "At that time it entered into force only for those States that had accepted the amendment.", "The amended text of the convention will apply automatically to any State that becomes a Party after 29 November 2013.For States that became party to the convention before that date and have not accepted the amendment, it will enter into force 60 days after they accept it." ], [ "Regulation of trade", "CITES works by subjecting international trade in specimens of listed taxa to controls as they move across international borders.", "CITES specimens can include a wide range of items including the whole animal/plant (whether alive or dead), or a product that contains a part or derivative of the listed taxa such as cosmetics or traditional medicines.Four types of trade are recognised by CITES - import, export, re-export (export of any specimen that has previously been imported) and introduction from the sea (transportation into a state of specimens of any species which were taken in the marine environment not under the jurisdiction of any state).", "The CITES definition of \"trade\" does not require a financial transaction to be occurring.", "All trade in specimens of species covered by CITES must be authorized through a system of permits and certificates prior to the trade taking place.", "CITES permits and certificates are issued by one or more Management Authorities in charge of administering the CITES system in each country.", "Management Authorities are advised by one or more Scientific Authorities on the effects of trade of the specimen on the status of CITES-listed species.", "CITES permits and certificates must be presented to relevant border authorities in each country in order to authorise the trade.Each party must enact their own domestic legislation to bring the provisions of CITES into effect in their territories.", "Parties may choose to take stricter domestic measures than CITES provides (for example by requiring permits/certificates in cases where they would not normally be needed or by prohibiting trade in some specimens).Illegally traded wildlife items seized by HM Revenue and Customs in the United Kingdom===Appendices===Over 40,900 species, subspecies and populations are protected under CITES.", "Each protected taxa or population is included in one of three lists called Appendices.", "The Appendix that lists a taxa or population reflects the level of the threat posed by international trade and the CITES controls that apply.Taxa may be split-listed meaning that some populations of a species are on one Appendix, while some are on another.", "The African bush elephant (''Loxodonta africana'') is currently split-listed, with all populations except those of Botswana, Namibia, South Africa and Zimbabwe listed in Appendix I.", "Those of Botswana, Namibia, South Africa and Zimbabwe are listed in Appendix II.", "There are also species that have only some populations listed in an Appendix.", "One example is the pronghorn (''Antilocapra americana''), a ruminant native to North America.", "Its Mexican population is listed in Appendix I, but its U.S. and Canadian populations are not listed (though certain U.S. populations in Arizona are nonetheless protected under other domestic legislation, in this case the Endangered Species Act).Taxa are proposed for inclusion, amendment or deletion in Appendices I and II at meetings of the Conference of the Parties (CoP), which are held approximately once every three years.", "Amendments to listing in Appendix III may be made unilaterally by individual parties.====Appendix I====Appendix I taxa are those that are threatened with extinction and to which the highest level of CITES protection is afforded.", "Commercial trade in wild-sourced specimens of these taxa is not permitted and non-commercial trade is strictly controlled by requiring an import permit and export permit to be granted by the relevant Management Authorities in each country before the trade occurs.Notable taxa listed in Appendix I include the red panda (''Ailurus fulgens''), western gorilla (''Gorilla gorilla''), the chimpanzee species (''Pan spp.", "''), tigers (''Panthera tigris'' subspecies), Asian elephant (''Elephas maximus''), some populations of African bush elephant (''Loxodonta africana''), and the monkey puzzle tree (''Araucaria araucana'').====Appendix II====Appendix II taxa are those that are not necessarily threatened with extinction, but trade must be controlled in order to avoid utilization incompatible with their survival.", "Appendix II taxa may also include species similar in appearance to species already listed in the Appendices.", "The vast majority of taxa listed under CITES are listed in Appendix II.", "Any trade in Appendix II taxa standardly requires a CITES export permit or re-export certificate to be granted by the Management Authority of the exporting country before the trade occurs.Examples of taxa listed on Appendix II are the great white shark (''Carcharodon carcharias''), the American black bear (''Ursus americanus''), Hartmann's mountain zebra (''Equus zebra hartmannae''), green iguana (''Iguana iguana''), queen conch (''Strombus gigas''), emperor scorpion (''Pandinus imperator''), Mertens' water monitor (''Varanus mertensi''), bigleaf mahogany (''Swietenia macrophylla''), lignum vitae (''Guaiacum officinale''), the chambered nautilus (''Nautilus pompilius''), all stony corals (''Scleractinia'' spp.", "), and American ginseng (''Panax quinquefolius'').====Appendix III====Appendix III species are those that are protected in at least one country, and that country has asked other CITES Parties for assistance in controlling the trade.Any trade in Appendix III species standardly requires a CITES export permit (if sourced from the country that listed the species) or a certificate of origin (from any other country) to be granted before the trade occurs.Examples of species listed on Appendix III and the countries that listed them are the Hoffmann's two-toed sloth (''Choloepus hoffmanni'') by Costa Rica, sitatunga (''Tragelaphus spekii'') by Ghana and African civet (''Civettictis civetta'') by Botswana.===Exemptions and special procedures===Under Article VII, the Convention allows for certain exceptions to the general trade requirements described above.====Pre-Convention specimens====CITES provides for a special process for specimens that were acquired before the provisions of the Convention applied to that specimen.", "These are known as \"pre-Convention\" specimens and must be granted a CITES pre-Convention certificate before the trade occurs.", "Only specimens legally acquired before the date on which the species concerned was first included in the Appendices qualify for this exemption.====Personal and household effects====CITES provides that the standard permit/certificate requirements for trade in CITES specimens do not generally apply if a specimen is a personal or household effect.", "However there are a number of situations where permits/certificates for personal or household effects are required and some countries choose to take stricter domestic measures by requiring permits/certificates for some or all personal or household effects.====Captive bred or artificially propagated specimens====CITES allows trade in specimens to follow special procedures if Management Authorities are satisfied that they are sourced from captive bred animals or artificially propagated plants.", "In the case of commercial trade of Appendix I taxa, captive bred or artificially propagated specimens may be traded as if they were Appendix II.", "This reduces the permit requirements from two permits (import/export) to one (export only).", "In the case of non-commercial trade, specimens may be traded with a certificate of captive breeding/artificial propagation issued by the Management Authority of the state of export in lieu of standard permits.====Scientific exchange====Standard CITES permit and certificates are not required for the non-commercial loan, donation or exchange between scientific or forensic institutions that have been registered by a Management Authority of their State.", "Consignments containing the specimens must carry a label issued or approved by that Management Authority (in some cases Customs Declaration labels may be used).", "Specimens that may be included under this provision include museum, herbarium, diagnostic and forensic research specimens.", "Registered institutions are listed on the CITES website." ], [ "Amendments and reservations", "Amendments to the Convention must be supported by a two-thirds majority who are \"present and voting\" and can be made during an extraordinary meeting of the COP if one-third of the Parties are interested in such a meeting.", "The Gaborone Amendment (1983) allows regional economic blocs to accede to the treaty.", "Trade with non-Party states is allowed, although permits and certificates are recommended to be issued by exporters and sought by importers.Species in the Appendices may be proposed for addition, change of Appendix, or de-listing (i.e., deletion) by any Party, whether or not it is a range State and changes may be made despite objections by range States if there is sufficient (2/3 majority) support for the listing.", "Species listings are made at the Conference of Parties.Upon acceding to the Convention or within 90 days of a species listing being amended, Parties may make reservations.", "In these cases, the party is treated as being a state that is not a Party to CITES with respect to trade in the species concerned.", "Notable reservations include those by Iceland, Japan, and Norway on various baleen whale species and those on Falconiformes by Saudi Arabia." ], [ "Shortcomings and concerns", "===Implementation===As of 2002, 50% of Parties lacked one or more of the four major CITES requirements - designation of Management and Scientific Authorities; laws prohibiting the trade in violation of CITES; penalties for such trade and laws providing for the confiscation of specimens.Although the Convention itself does not provide for arbitration or dispute in the case of noncompliance, 36 years of CITES in practice has resulted in several strategies to deal with infractions by Parties.", "The Secretariat, when informed of an infraction by a Party, will notify all other parties.", "The Secretariat will give the Party time to respond to the allegations and may provide technical assistance to prevent further infractions.", "Other actions the Convention itself does not provide for but that derive from subsequent COP resolutions may be taken against the offending Party.", "These include:*Mandatory confirmation of all permits by the Secretariat*Suspension of cooperation from the Secretariat*A formal warning*A visit by the Secretariat to verify capacity*Recommendations to all Parties to suspend CITES related trade with the offending party*Dictation of corrective measures to be taken by the offending Party before the Secretariat will resume cooperation or recommend resumption of tradeBilateral sanctions have been imposed on the basis of national legislation (e.g.", "the USA used certification under the Pelly Amendment to get Japan to revoke its reservation to hawksbill turtle products in 1991, thus reducing the volume of its exports).Infractions may include negligence with respect to permit issuing, excessive trade, lax enforcement, and failing to produce annual reports (the most common).===Approach to biodiversity conservation===General limitations about the structure and philosophy of CITES include: by design and intent it focuses on trade at the species level and does not address habitat loss, ecosystem approaches to conservation, or poverty; it seeks to prevent unsustainable use rather than promote sustainable use (which generally conflicts with the Convention on Biological Diversity), although this has been changing (see Nile crocodile, African elephant, South African white rhino case studies in Hutton and Dickinson 2000).", "It does not explicitly address market demand.", "In fact, CITES listings have been demonstrated to increase financial speculation in certain markets for high value species.", "Funding does not provide for increased on-the-ground enforcement (it must apply for bilateral aid for most projects of this nature).There has been increasing willingness within the Parties to allow for trade in products from well-managed populations.", "For instance, sales of the South African white rhino have generated revenues that helped pay for protection.", "Listing the species on Appendix I increased the price of rhino horn (which fueled more poaching), but the species survived wherever there was adequate on-the-ground protection.", "Thus field protection may be the primary mechanism that saved the population, but it is likely that field protection would not have been increased without CITES protection.", "In another instance, the United States initially stopped exports of bobcat and lynx hides in 1977 when it first implemented CITES for lack of data to support no detriment findings.", "However, in this Federal Register notice, issued by William Yancey Brown, the U.S.", "Endangered Species Scientific Authority (ESSA) established a framework of no detriment findings for each state and the Navajo nation and indicated that approval would be forthcoming if the states and Navajo nation provided evidence that their furbearer management programs assured the species would be conserved.", "Management programs for these species expanded rapidly, including tagging for export, and are currently recognized in program approvals under regulations of the U.S.", "Fish and Wildlife Service.===Drafting===By design, CITES regulates and monitors trade in the manner of a \"negative list\" such that trade in all species is permitted and unregulated ''unless'' the species in question appears on the Appendices or looks very much like one of those taxa.", "Then and only then, trade is regulated or constrained.", "Because the remit of the Convention covers millions of species of plants and animals, and tens of thousands of these taxa are potentially of economic value, in practice this negative list approach effectively forces CITES signatories to expend limited resources on just a select few, leaving many species to be traded with neither constraint nor review.", "For example, recently several bird classified as threatened with extinction appeared in the legal wild bird trade because the CITES process never considered their status.", "If a \"positive list\" approach were taken, only species evaluated and approved for the positive list would be permitted in trade, thus lightening the review burden for member states and the Secretariat, and also preventing inadvertent legal trade threats to poorly known species.Specific weaknesses in the text include: it does not stipulate guidelines for the 'non-detriment' finding required of national Scientific Authorities; non-detriment findings require copious amounts of information; the 'household effects' clause is often not rigid enough/specific enough to prevent CITES violations by means of this Article (VII); non-reporting from Parties means Secretariat monitoring is incomplete; and it has no capacity to address domestic trade in listed species.In order to ensure that the General Agreement on Tariffs and Trade (GATT) was not violated, the Secretariat of GATT was consulted during the drafting process.===Animal sourced pathogens===During the coronavirus pandemic in 2020 CEO Ivonne Higuero noted that illegal wildlife trade not only helps to destroy habitats, but these habitats create a safety barrier for humans that can prevent pathogens from animals passing themselves on to people.===Reform suggestions===Suggestions for improvement in the operation of CITES include: more regular missions by the Secretariat (not reserved just for high-profile species); improvement of national legislation and enforcement; better reporting by Parties (and the consolidation of information from all sources-NGOs, TRAFFIC, the wildlife trade monitoring network and Parties); more emphasis on enforcement-including a technical committee enforcement officer; the development of CITES Action Plans (akin to Biodiversity Action Plans related to the Convention on Biological Diversity) including: designation of Scientific/Management Authorities and national enforcement strategies; incentives for reporting and timelines for both Action Plans and reporting.", "CITES would benefit from access to Global Environment Facility (GEF), funds-although this is difficult given the GEFs more ecosystem approach-or other more regular funds.", "Development of a future mechanism similar to that of the Montreal Protocol (developed nations contribute to a fund for developing nations) could allow more funds for non-Secretariat activities.=== TRAFFIC Data ===From 2005 to 2009 the legal trade corresponded with these numbers:* 317,000 live birds* More than 2 million live reptiles* 2.5 million crocodile skins* 2.1 million snake skins* 73 tons of caviar* 1.1 million beaver skins* Millions of pieces of coral* 20,000 mammalian hunting trophiesIn the 1990s the annual trade of legal animal products was $160 billion annually.", "In 2009 the estimated value almost doubled to $300 billion.Additional information about the documented trade can be extracted through queries on the CITES website." ], [ "Meetings", "The Conference of the Parties (CoP) is held once every three years.", "The location of the next CoP is chosen at the close of each CoP by a secret ballot vote.The CITES Committees (Animals Committee, Plants Committee and Standing Committee) hold meetings during each year that does not have a CoP, while the Standing committee meets also in years with a CoP.", "The Committee meetings take place in Geneva, Switzerland (where the Secretariat of the CITES Convention is located), unless another country offers to host the meeting.", "The Secretariat is administered by UNEP.", "The Animals and Plants Committees have sometimes held joint meetings.", "The previous joint meeting was held in March 2012 in Dublin, Ireland, and the latest one was held in Veracruz, Mexico, in May 2014.MeetingCityCountryDurationCoP 1Bern 2–6 November 1976CoP 2San José 19–30 March 1979CoP 3New Delhi 25 February – 8 March 1981CoP 4Gaborone 19 – 30 April 1983CoP 5Buenos Aires 22 April – 3 May 1985CoP 6Ottawa 12–24 July 1987CoP 7Lausanne 9–20 October 1989CoP 8Kyoto 2–13 March 1992CoP 9Fort Lauderdale 7–18 November 1994CoP 10Harare 9–20 June 1997CoP 11Nairobi 10–20 April 2000CoP 12Santiago de Chile 3–15 November 2002CoP 13Bangkok 2–14 October 2004CoP 14The Hague 3–15 June 2007CoP 15Doha 13–25 March 2010CoP 16Bangkok 3–14 March 2013CoP 17Johannesburg 24 September – 5 October 2016CoP 18Geneva 17–28 August 2019CoP 19Panama City 14–25 November 2022A current list of upcoming meetings appears on the CITES calendar.At the seventeenth Conference of the Parties (CoP 17), Namibia and Zimbabwe introduced proposals to amend their listing of elephant populations in Appendix II.", "Instead, they wished to establish controlled trade in all elephant specimens, including ivory.", "They argue that revenue from regulated trade could be used for elephant conservation and rural communities' development.", "However, both proposals were opposed by the US and other countries." ], [ "See also", "*Environmental agreements*Illegal logging *IUCN Red List*Ivory trade*Lacey Act*List of species protected by CITES Appendix I*List of species protected by CITES Appendix II*List of species protected by CITES Appendix III*Shark finning*Wildlife conservation*Wildlife Enforcement Monitoring System*Wildlife management*Wildlife smuggling*World Wildlife Day" ], [ "Footnotes" ], [ "References" ], [ "Further reading", "*Oldfield, S. and McGough, N.", "(Comp.)", "2007.A CITES manual for botanic gardens English version, Spanish version, Italian version Botanic Gardens Conservation International (BGCI)" ], [ "External links", "* * CITES Profile on database of market governance mechanisms (archived 13 March 2016);Member countries (Parties)* Chronological list of Parties* Alphabetical list of Parties at CITES and at the depositary (PDF)* National contacts (archived 20 January 2011);Lists of species included in Appendices I, II and III (i.e.", "species protected by CITES)* Explanation of the Appendices* Number of species on the Appendices* Species lists (Appendices I, II and III)" ] ]
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[ [ "Environmental Modification Convention" ], [ "Introduction", "The '''Environmental Modification Convention''' ('''ENMOD'''), formally the '''Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques''', is an international treaty prohibiting the military or other hostile use of environmental modification techniques having widespread, long-lasting or severe effects.", "It opened for signature on 18 May 1977 in Geneva and entered into force on 5 October 1978.The Convention bans weather warfare, which is the use of weather modification techniques for the purposes of inducing damage or destruction.", "The Convention on Biological Diversity of 2010 would also ban some forms of weather modification or geoengineering.Many states do not regard this as a complete ban on the use of herbicides in warfare, such as Agent Orange, but it does require case-by-case consideration." ], [ "Parties", "The convention was signed by 48 states; 16 of the signatories have not ratified.", "As of 2022 the convention has 78 state parties." ], [ "History", "The problem of artificial modification of the environment for military or other hostile purposes was brought to the international agenda in the early 1970s.", "Following the US decision of July 1972 to renounce the use of climate modification techniques for hostile purposes, the 1973 resolution by the US Senate calling for an international agreement \"prohibiting the use of any environmental or geophysical modification activity as a weapon of war\", and an in-depth review by the Department of Defense of the military aspects of weather and other environmental modification techniques, US decided to seek agreement with the Soviet Union to explore the possibilities of an international agreement.In July 1974, US and USSR agreed to hold bilateral discussions on measures to overcome the danger of the use of environmental modification techniques for military purposes and three subsequent rounds of discussions in 1974 and 1975.In August 1975, US and USSR tabled identical draft texts of a convention at the Conference of the Committee on Disarmament (CCD), Conference on Disarmament, where intensive negotiations resulted in a modified text and understandings regarding four articles of this Convention in 1976.The convention was approved by Resolution 31/72 of the General Assembly of the United Nations on 10 December 1976, by 96 to 8 votes with 30 abstentions." ], [ "Environmental Modification Technique", "Environmental Modification Technique includes any technique for changing – through the deliberate manipulation of natural processes – the dynamics, composition or structure of the earth, including its biota, lithosphere, hydrosphere and atmosphere, or of outer space." ], [ "Structure of ENMOD", "The Convention contains ten articles and one Annex on the Consultative Committee of Experts.", "Integral part of the convention are also the Understandings relating to articles I, II, III and VIII.", "These Understandings are not incorporated into the convention but are part of the negotiating record and were included in the report transmitted by the Conference of the Committee on Disarmament to the United Nations General Assembly in September 1976 Report of the Conference of the Committee on Disarmament, Volume I, General Assembly Official records: Thirty-first session, Supplement No.", "27 (A/31/27), New York, United Nations, 1976, pp.", "91–92." ], [ "Anthropogenic climate change", "ENMOD treaty members are responsible for 83% of carbon dioxide emissions since the treaty entered into force in 1978.The ENMOD treaty could potentially be used by ENMOD member states seeking climate-change loss and damage compensation from other ENMOD member states at the International Court of Justice.", "With the knowledge that carbon dioxide emissions can enhance extreme weather events, the continued unmitigated greenhouse gas emissions from some ENMOD member states could be viewed as ‘reckless’ in the context of deliberately declining emissions from other ENMOD member states.", "It is unclear whether the International Court of Justice will consider the ENMOD treaty when it issues a legal opinion on international climate change obligations requested by the United Nations General Assembly on 29 March 2023." ], [ "See also", "* Arms control agreements* Environmental agreements* Climate engineering* Operation Popeye* United Nations Convention on Environmental Modification" ], [ "References", "* Welcome!", "| UN GENEVA" ], [ "External links", "* The text of the agreement compiled by the NGO Committee on Education* Ratifications* A Political Primer on the ENMOD Convention from the Sunshine Project." ] ]
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[ [ "Chaitin's constant" ], [ "Introduction", "In the computer science subfield of algorithmic information theory, a '''Chaitin constant''' ('''Chaitin omega number''') or '''halting probability''' is a real number that, informally speaking, represents the probability that a randomly constructed program will halt.", "These numbers are formed from a construction due to Gregory Chaitin.Although there are infinitely many halting probabilities, one for each method of encoding programs, it is common to use the letter Ω to refer to them as if there were only one.", "Because Ω depends on the program encoding used, it is sometimes called '''Chaitin's construction''' when not referring to any specific encoding.Each halting probability is a normal and transcendental real number that is not computable, which means that there is no algorithm to compute its digits.", "Each halting probability is Martin-Löf random, meaning there is not even any algorithm which can reliably guess its digits." ], [ "Background", "The definition of a halting probability relies on the existence of a '''prefix-free universal computable function.'''", "Such a function, intuitively, represents a programming language with the property that no valid program can be obtained as a proper extension of another valid program.Suppose that ''F'' is a partial function that takes one argument, a finite binary string, and possibly returns a single binary string as output.", "The function ''F'' is called '''computable''' if there is a Turing machine that computes it, in the sense that for any finite binary strings ''x'' and ''y,'' ''F(x) = y'' if and only if the Turing machine halts with ''y'' on its tape when given the input ''x''.The function ''F'' is called '''universal''' if the following property holds: for every computable function ''f'' of a single variable there is a string ''w'' such that for all ''x'', ''F''(''w'' ''x'') = ''f''(''x''); here ''w'' ''x'' represents the concatenation of the two strings ''w'' and ''x''.", "This means that ''F'' can be used to simulate any computable function of one variable.", "Informally, ''w'' represents a \"script\" for the computable function ''f'', and ''F'' represents an \"interpreter\" that parses the script as a prefix of its input and then executes it on the remainder of input.The '''domain''' of ''F'' is the set of all inputs ''p'' on which it is defined.", "For ''F'' that are universal, such a ''p'' can generally be seen both as the concatenation of a program part and a data part, and as a single program for the function ''F''.The function ''F'' is called '''prefix-free''' if there are no two elements ''p'', ''p′'' in its domain such that ''p′'' is a proper extension of ''p''.", "This can be rephrased as: the domain of ''F'' is a prefix-free code (instantaneous code) on the set of finite binary strings.", "A simple way to enforce prefix-free-ness is to use machines whose means of input is a binary stream from which bits can be read one at a time.", "There is no end-of-stream marker; the end of input is determined by when the universal machine decides to stop reading more bits, and the remaining bits are not considered part of the accepted string.", "Here, the difference between the two notions of program mentioned in the last paragraph becomes clear; one is easily recognized by some grammar, while the other requires arbitrary computation to recognize.The domain of any universal computable function is a computably enumerable set but never a computable set.", "The domain is always Turing equivalent to the halting problem." ], [ "Definition", "Let ''P''F be the domain of a prefix-free universal computable function ''F''.", "The constant ΩF is then defined as:,where denotes the length of a string ''p''.", "This is an infinite sum which has one summand for every ''p'' in the domain of ''F''.", "The requirement that the domain be prefix-free, together with Kraft's inequality, ensures that this sum converges to a real number between 0 and 1.If ''F'' is clear from context then ΩF may be denoted simply Ω, although different prefix-free universal computable functions lead to different values of Ω." ], [ "Relationship to the halting problem", "Knowing the first ''N'' bits of Ω, one could calculate the halting problem for all programs of a size up to ''N''.", "Let the program ''p'' for which the halting problem is to be solved be ''N'' bits long.", "In dovetailing fashion, all programs of all lengths are run, until enough have halted to jointly contribute enough probability to match these first ''N'' bits.", "If the program ''p'' hasn't halted yet, then it never will, since its contribution to the halting probability would affect the first ''N'' bits.", "Thus, the halting problem would be solved for ''p''.Because many outstanding problems in number theory, such as Goldbach's conjecture, are equivalent to solving the halting problem for special programs (which would basically search for counter-examples and halt if one is found), knowing enough bits of Chaitin's constant would also imply knowing the answer to these problems.", "But as the halting problem is not generally solvable, and therefore calculating any but the first few bits of Chaitin's constant is not possible, this just reduces hard problems to impossible ones, much like trying to build an oracle machine for the halting problem would be." ], [ "Interpretation as a probability", "The Cantor space is the collection of all infinite sequences of 0s and 1s.", "A halting probability can be interpreted as the measure of a certain subset of Cantor space under the usual probability measure on Cantor space.", "It is from this interpretation that halting probabilities take their name.The probability measure on Cantor space, sometimes called the fair-coin measure, is defined so that for any binary string ''x'' the set of sequences that begin with ''x'' has measure 2−|''x''|.", "This implies that for each natural number ''n'', the set of sequences ''f'' in Cantor space such that ''f''(''n'') = 1 has measure 1/2, and the set of sequences whose ''n''th element is 0 also has measure 1/2.Let ''F'' be a prefix-free universal computable function.", "The domain ''P'' of ''F'' consists of an infinite set of binary strings:.Each of these strings ''p''''i'' determines a subset ''S''''i'' of Cantor space; the set ''S''''i'' contains all sequences in cantor space that begin with ''p''''i''.", "These sets are disjoint because ''P'' is a prefix-free set.", "The sum:represents the measure of the set :.In this way, Ω''F'' represents the probability that a randomly selected infinite sequence of 0s and 1s begins with a bit string (of some finite length) that is in the domain of ''F''.", "It is for this reason that Ω''F'' is called a halting probability." ], [ "Properties", "Each Chaitin constant Ω has the following properties:* It is algorithmically random (also known as Martin-Löf random or 1-random).", "This means that the shortest program to output the first ''n'' bits of Ω must be of size at least ''n'' − O(1).", "This is because, as in the Goldbach example, those ''n'' bits enable us to find out exactly which programs halt among all those of length at most ''n''.", "* As a consequence, it is a normal number, which means that its digits are equidistributed as if they were generated by tossing a fair coin.", "* It is not a computable number; there is no computable function that enumerates its binary expansion, as discussed below.", "* The set of rational numbers ''q'' such that ''q'' Ω is not computably enumerable.", "(Reason: every left-c.e.", "real with this property is computable, which Ω isn't.", ")* Ω is an arithmetical number.", "* It is Turing equivalent to the halting problem and thus at level of the arithmetical hierarchy.Not every set that is Turing equivalent to the halting problem is a halting probability.", "A finer equivalence relation, '''Solovay equivalence''', can be used to characterize the halting probabilities among the left-c.e.", "reals.", "One can show that a real number in 0,1 is a Chaitin constant (i.e.", "the halting probability of some prefix-free universal computable function) if and only if it is left-c.e.", "and algorithmically random.", "Ω is among the few definable algorithmically random numbers and is the best-known algorithmically random number, but it is not at all typical of all algorithmically random numbers." ], [ "Uncomputability", "A real number is called computable if there is an algorithm which, given ''n'', returns the first ''n'' digits of the number.", "This is equivalent to the existence of a program that enumerates the digits of the real number.No halting probability is computable.", "The proof of this fact relies on an algorithm which, given the first ''n'' digits of Ω, solves Turing's halting problem for programs of length up to ''n''.", "Since the halting problem is undecidable, Ω cannot be computed.The algorithm proceeds as follows.", "Given the first ''n'' digits of Ω and a ''k'' ≤ ''n'', the algorithm enumerates the domain of ''F'' until enough elements of the domain have been found so that the probability they represent is within 2−(''k''+1) of Ω.", "After this point, no additional program of length ''k'' can be in the domain, because each of these would add 2−''k'' to the measure, which is impossible.", "Thus the set of strings of length ''k'' in the domain is exactly the set of such strings already enumerated." ], [ "Algorithmic randomness", "A real number is random if the binary sequence representing the real number is an algorithmically random sequence.", "Calude, Hertling, Khoussainov, and Wang showed that a recursively enumerable real number is an algorithmically random sequence if and only if it is a Chaitin's Ω number." ], [ "Incompleteness theorem for halting probabilities", "For each specific consistent effectively represented axiomatic system for the natural numbers, such as Peano arithmetic, there exists a constant ''N'' such that no bit of Ω after the ''N''th can be proven to be 1 or 0 within that system.", "The constant ''N'' depends on how the formal system is effectively represented, and thus does not directly reflect the complexity of the axiomatic system.", "This incompleteness result is similar to Gödel's incompleteness theorem in that it shows that no consistent formal theory for arithmetic can be complete." ], [ "Super Omega", "As mentioned above, the first n bits of Gregory Chaitin's constant Ω are random or incompressible in the sense that we cannot compute them by a halting algorithm with fewer than n-O(1) bits.", "However, consider the short but never halting algorithm which systematically lists and runs all possible programs; whenever one of them halts its probability gets added to the output (initialized by zero).", "After finite time the first n bits of the output will never change any more (it does not matter that this time itself is not computable by a halting program).", "So there is a short non-halting algorithm whose output converges (after finite time) onto the first n bits of Ω.", "In other words, the enumerable first n bits of Ω are highly compressible in the sense that they are limit-computable by a very short algorithm; they are not random with respect to the set of enumerating algorithms.", "Jürgen Schmidhuber (2000) constructed a limit-computable \"Super Ω\" which in a sense is much more random than the original limit-computable Ω, as one cannot significantly compress the Super Ω by any enumerating non-halting algorithm.For an alternative \"Super Ω\", the universality probability of a prefix-free Universal Turing Machine (UTM) namely, the probability that it remains universal even when every input of it (as a binary string) is prefixed by a random binary string can be seen as the non-halting probability of a machine with oracle the third iteration of the halting problem (i.e., using Turing Jump notation)." ], [ "See also", "* Gödel's incompleteness theorems* Kolmogorov complexity" ], [ "References", "===Works cited===* * * Introduction chapter full-text.", "* Preprint: Algorithmic Theories of Everything (arXiv: quant-ph/ 0011122)" ], [ "External links", "* Aspects of Chaitin's Omega Survey article discussing recent advances in the study of Chaitin's Omega.", "* Omega and why maths has no TOEs article based on one written by Gregory Chaitin which appeared in the August 2004 edition of Mathematics Today, on the occasion of the 50th anniversary of Alan Turing's death.", "* ''The Limits of Reason'', Gregory Chaitin, originally appeared in Scientific American, March 2006.", "* Limit-computable Super Omega more random than Omega and generalizations of algorithmic information, by Jürgen Schmidhuber" ] ]
wikipedia
[ [ "Computable number" ], [ "Introduction", "π can be computed to arbitrary precision, while almost every real number is not computable.In mathematics, '''computable numbers''' are the real numbers that can be computed to within any desired precision by a finite, terminating algorithm.", "They are also known as the '''recursive numbers''', '''effective numbers''' or the '''computable reals''' or '''recursive reals'''.", "The concept of a computable real number was introduced by Emile Borel in 1912, using the intuitive notion of computability available at the time.Equivalent definitions can be given using μ-recursive functions, Turing machines, or λ-calculus as the formal representation of algorithms.", "The computable numbers form a real closed field and can be used in the place of real numbers for many, but not all, mathematical purposes." ], [ "Informal definition using a Turing machine as example", "In the following, Marvin Minsky defines the numbers to be computed in a manner similar to those defined by Alan Turing in 1936; i.e., as \"sequences of digits interpreted as decimal fractions\" between 0 and 1: The key notions in the definition are (1) that some ''n'' is specified at the start, (2) for any ''n'' the computation only takes a finite number of steps, after which the machine produces the desired output and terminates.An alternate form of (2) – the machine successively prints all ''n'' of the digits on its tape, halting after printing the ''n''th – emphasizes Minsky's observation: (3) That by use of a Turing machine, a ''finite'' definition – in the form of the machine's state table – is being used to define what is a potentially ''infinite'' string of decimal digits.This is however not the modern definition which only requires the result be accurate to within any given accuracy.", "The informal definition above is subject to a rounding problem called the table-maker's dilemma whereas the modern definition is not." ], [ "Formal definition", "A real number ''a'' is '''computable''' if it can be approximated by some computable function in the following manner: given any positive integer ''n'', the function produces an integer ''f''(''n'') such that::There are two similar definitions that are equivalent:*There exists a computable function which, given any positive rational error bound , produces a rational number ''r'' such that *There is a computable sequence of rational numbers converging to such that for each ''i''.There is another equivalent definition of computable numbers via computable Dedekind cuts.", "A '''computable Dedekind cut''' is a computable function which when provided with a rational number as input returns or , satisfying the following conditions:::::An example is given by a program ''D'' that defines the cube root of 3.Assuming this is defined by:::A real number is computable if and only if there is a computable Dedekind cut ''D'' corresponding to it.", "The function ''D'' is unique for each computable number (although of course two different programs may provide the same function).A complex number is called computable if its real and imaginary parts are computable." ], [ "Properties", "===Not computably enumerable===Assigning a Gödel number to each Turing machine definition produces a subset of the natural numbers corresponding to the computable numbers and identifies a surjection from to the computable numbers.", "There are only countably many Turing machines, showing that the computable numbers are subcountable.", "The set of these Gödel numbers, however, is not computably enumerable (and consequently, neither are subsets of that are defined in terms of it).", "This is because there is no algorithm to determine which Gödel numbers correspond to Turing machines that produce computable reals.", "In order to produce a computable real, a Turing machine must compute a total function, but the corresponding decision problem is in Turing degree '''0′′'''.", "Consequently, there is no surjective computable function from the natural numbers to the set of machines representing computable reals, and Cantor's diagonal argument cannot be used constructively to demonstrate uncountably many of them.While the set of real numbers is uncountable, the set of computable numbers is classically countable and thus almost all real numbers are not computable.", "Here, for any given computable number the well ordering principle provides that there is a minimal element in which corresponds to , and therefore there exists a subset consisting of the minimal elements, on which the map is a bijection.", "The inverse of this bijection is an injection into the natural numbers of the computable numbers, proving that they are countable.", "But, again, this subset is not computable, even though the computable reals are themselves ordered.===Properties as a field===The arithmetical operations on computable numbers are themselves computable in the sense that whenever real numbers ''a'' and ''b'' are computable then the following real numbers are also computable: ''a + b'', ''a - b'', ''ab'', and ''a/b'' if ''b'' is nonzero.These operations are actually ''uniformly computable''; for example, there is a Turing machine which on input (''A'',''B'',) produces output ''r'', where ''A'' is the description of a Turing machine approximating ''a'', ''B'' is the description of a Turing machine approximating ''b'', and ''r'' is an approximation of ''a''+''b''.The fact that computable real numbers form a field was first proved by Henry Gordon Rice in 1954.Computable reals however do not form a computable field, because the definition of a computable field requires effective equality.===Non-computability of the ordering===The order relation on the computable numbers is not computable.", "Let ''A'' be the description of a Turing machine approximating the number .", "Then there is no Turing machine which on input ''A'' outputs \"YES\" if and \"NO\" if To see why, suppose the machine described by ''A'' keeps outputting 0 as approximations.", "It is not clear how long to wait before deciding that the machine will ''never'' output an approximation which forces ''a'' to be positive.", "Thus the machine will eventually have to guess that the number will equal 0, in order to produce an output; the sequence may later become different from 0.This idea can be used to show that the machine is incorrect on some sequences if it computes a total function.", "A similar problem occurs when the computable reals are represented as Dedekind cuts.", "The same holds for the equality relation : the equality test is not computable.While the full order relation is not computable, the restriction of it to pairs of unequal numbers is computable.", "That is, there is a program that takes as input two Turing machines ''A'' and ''B'' approximating numbers and , where , and outputs whether or It is sufficient to use -approximations where so by taking increasingly small (approaching 0), one eventually can decide whether or ===Other properties===The computable real numbers do not share all the properties of the real numbers used in analysis.", "For example, the least upper bound of a bounded increasing computable sequence of computable real numbers need not be a computable real number.", "A sequence with this property is known as a Specker sequence, as the first construction is due to Ernst Specker in 1949.Despite the existence of counterexamples such as these, parts of calculus and real analysis can be developed in the field of computable numbers, leading to the study of computable analysis.Every computable number is arithmetically definable, but not vice versa.", "There are many arithmetically definable, noncomputable real numbers, including:*any number that encodes the solution of the halting problem (or any other undecidable problem) according to a chosen encoding scheme.", "*Chaitin's constant, , which is a type of real number that is Turing equivalent to the halting problem.Both of these examples in fact define an infinite set of definable, uncomputable numbers, one for each Universal Turing machine.A real number is computable if and only if the set of natural numbers it represents (when written in binary and viewed as a characteristic function) is computable.The set of computable real numbers (as well as every countable, densely ordered subset of computable reals without ends) is order-isomorphic to the set of rational numbers." ], [ "Digit strings and the Cantor and Baire spaces", "Turing's original paper defined computable numbers as follows:(The decimal expansion of ''a'' only refers to the digits following the decimal point.", ")Turing was aware that this definition is equivalent to the -approximation definition given above.", "The argument proceeds as follows: if a number is computable in the Turing sense, then it is also computable in the sense: if , then the first ''n'' digits of the decimal expansion for ''a'' provide an approximation of ''a''.", "For the converse, we pick an computable real number ''a'' and generate increasingly precise approximations until the ''n''th digit after the decimal point is certain.", "This always generates a decimal expansion equal to ''a'' but it may improperly end in an infinite sequence of 9's in which case it must have a finite (and thus computable) proper decimal expansion.Unless certain topological properties of the real numbers are relevant, it is often more convenient to deal with elements of (total 0,1 valued functions) instead of reals numbers in .", "The members of can be identified with binary decimal expansions, but since the decimal expansions and denote the same real number, the interval can only be bijectively (and homeomorphically under the subset topology) identified with the subset of not ending in all 1's.Note that this property of decimal expansions means that it is impossible to effectively identify the computable real numbers defined in terms of a decimal expansion and those defined in the approximation sense.", "Hirst has shown that there is no algorithm which takes as input the description of a Turing machine which produces approximations for the computable number ''a'', and produces as output a Turing machine which enumerates the digits of ''a'' in the sense of Turing's definition.", "Similarly, it means that the arithmetic operations on the computable reals are not effective on their decimal representations as when adding decimal numbers.", "In order to produce one digit, it may be necessary to look arbitrarily far to the right to determine if there is a carry to the current location.", "This lack of uniformity is one reason why the contemporary definition of computable numbers uses approximations rather than decimal expansions.However, from a computability theoretic or measure theoretic perspective, the two structures and are essentially identical.", "Thus, computability theorists often refer to members of as reals.", "While is totally disconnected, for questions about classes or randomness it is easier to work in .Elements of are sometimes called reals as well and though containing a homeomorphic image of , isn't even locally compact (in addition to being totally disconnected).", "This leads to genuine differences in the computational properties.", "For instance the satisfying , with quantifier free, must be computable while the unique satisfying a universal formula may have an arbitrarily high position in the hyperarithmetic hierarchy." ], [ "Use in place of the reals", "The computable numbers include the specific real numbers which appear in practice, including all real algebraic numbers, as well as ''e'', ''π'', and many other transcendental numbers.", "Though the computable reals exhaust those reals we can calculate or approximate, the assumption that all reals are computable leads to substantially different conclusions about the real numbers.", "The question naturally arises of whether it is possible to dispose of the full set of reals and use computable numbers for all of mathematics.", "This idea is appealing from a constructivist point of view, and has been pursued by what Errett Bishop and Fred Richman call the ''Russian school'' of constructive mathematics.", "To actually develop analysis over computable numbers, some care must be taken.", "For example, if one uses the classical definition of a sequence, the set of computable numbers is not closed under the basic operation of taking the supremum of a bounded sequence (for example, consider a Specker sequence, see the section above).", "This difficulty is addressed by considering only sequences which have a computable modulus of convergence.", "The resulting mathematical theory is called computable analysis." ], [ "Implementations of exact arithmetic", "Computer packages representing real numbers as programs computing approximations have been proposed as early as 1985, under the name \"exact arithmetic\".", "Modern examples include the CoRN library (Coq), and the RealLib package (C++).", "A related line of work is based on taking a real RAM program and running it with rational or floating-point numbers of sufficient precision, such as the package." ], [ "See also", "*Constructible number*Definable number*Semicomputable function*Transcomputational problem" ], [ "Notes" ], [ "References", "******* Computable numbers (and Turing's a-machines) were introduced in this paper; the definition of computable numbers uses infinite decimal sequences.", "*" ], [ "Further reading", "* This paper describes the development of the calculus over the computable number field.", "*** §1.3.2 introduces the definition by nested sequences of intervals converging to the singleton real.", "Other representations are discussed in §4.1.", "*" ] ]
wikipedia
[ [ "Electric current" ], [ "Introduction", "An '''electric current''' is a flow of charged particles, such as electrons or ions, moving through an electrical conductor or space.", "It is defined as the net rate of flow of electric charge through a surface.", "The moving particles are called charge carriers, which may be one of several types of particles, depending on the conductor.", "In electric circuits the charge carriers are often electrons moving through a wire.", "In semiconductors they can be electrons or holes.", "In an electrolyte the charge carriers are ions, while in plasma, an ionized gas, they are ions and electrons.In the International System of Units (SI), electric current is expressed in units of ampere (sometimes called an \"amp\", symbol A), which is equivalent to one coulomb per second.", "The ampere is an SI base unit and electric current is a base quantity in the International System of Quantities (ISQ).", "Electric current is also known as '''amperage''' and is measured using a device called an ''ammeter''.Electric currents create magnetic fields, which are used in motors, generators, inductors, and transformers.", "In ordinary conductors, they cause Joule heating, which creates light in incandescent light bulbs.", "Time-varying currents emit electromagnetic waves, which are used in telecommunications to broadcast information." ], [ "Symbol", "The conventional symbol for current is , which originates from the French phrase , (current intensity).", "Current intensity is often referred to simply as ''current''.", "The symbol was used by André-Marie Ampère, after whom the unit of electric current is named, in formulating Ampère's force law (1820).", "The notation travelled from France to Great Britain, where it became standard, although at least one journal did not change from using to until 1896.==Conventions==The electrons, the charge carriers in an electrical circuit, flow in the opposite direction of the conventional electric current.symbol for a battery in a circuit diagram.The conventional direction of current, also known as ''conventional current'', is arbitrarily defined as the direction in which charges flow.", "In a conductive material, the moving charged particles that constitute the electric current are called charge carriers.", "In metals, which make up the wires and other conductors in most electrical circuits, the positively charged atomic nuclei of the atoms are held in a fixed position, and the negatively charged electrons are the charge carriers, free to move about in the metal.", "In other materials, notably the semiconductors, the charge carriers can be positive ''or'' negative, depending on the dopant used.", "Positive and negative charge carriers may even be present at the same time, as happens in an electrolyte in an electrochemical cell.A flow of positive charges gives the same electric current, and has the same effect in a circuit, as an equal flow of negative charges in the opposite direction.", "Since current can be the flow of either positive or negative charges, or both, a convention is needed for the direction of current that is independent of the type of charge carriers.", "Negatively charged carriers, such as the electrons (the charge carriers in metal wires and many other electronic circuit components), therefore flow in the opposite direction of conventional current flow in an electrical circuit.===Reference direction===A current in a wire or circuit element can flow in either of two directions.", "When defining a variable to represent the current, the direction representing positive current must be specified, usually by an arrow on the circuit schematic diagram.", "This is called the ''reference direction'' of the current .", "When analyzing electrical circuits, the actual direction of current through a specific circuit element is usually unknown until the analysis is completed.", "Consequently, the reference directions of currents are often assigned arbitrarily.", "When the circuit is solved, a negative value for the current implies the actual direction of current through that circuit element is opposite that of the chosen reference direction." ], [ "Ohm's law", "Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points.", "Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship:where ''I'' is the current through the conductor in units of amperes, ''V'' is the potential difference measured ''across'' the conductor in units of volts, and ''R'' is the resistance of the conductor in units of ohms.", "More specifically, Ohm's law states that the ''R'' in this relation is constant, independent of the current." ], [ "Alternating and direct current", "In alternating current (AC) systems, the movement of electric charge periodically reverses direction.", "AC is the form of electric power most commonly delivered to businesses and residences.", "The usual waveform of an AC power circuit is a sine wave, though certain applications use alternative waveforms, such as triangular or square waves.", "Audio and radio signals carried on electrical wires are also examples of alternating current.", "An important goal in these applications is recovery of information encoded (or ''modulated'') onto the AC signal.In contrast, direct current (DC) refers to a system in which the movement of electric charge in only one direction (sometimes called unidirectional flow).", "Direct current is produced by sources such as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type.", "Alternating current can also be converted to direct current through use of a rectifier.", "Direct current may flow in a conductor such as a wire, but can also flow through semiconductors, insulators, or even through a vacuum as in electron or ion beams.", "An old name for direct current was ''galvanic current''." ], [ "Occurrences", "Natural observable examples of electric current include lightning, static electric discharge, and the solar wind, the source of the polar auroras.Man-made occurrences of electric current include the flow of conduction electrons in metal wires such as the overhead power lines that deliver electrical energy across long distances and the smaller wires within electrical and electronic equipment.", "Eddy currents are electric currents that occur in conductors exposed to changing magnetic fields.", "Similarly, electric currents occur, particularly in the surface, of conductors exposed to electromagnetic waves.", "When oscillating electric currents flow at the correct voltages within radio antennas, radio waves are generated.In electronics, other forms of electric current include the flow of electrons through resistors or through the vacuum in a vacuum tube, the flow of ions inside a battery, and the flow of holes within metals and semiconductors.", "A biological example of current is the flow of ions in neurons and nerves, responsible for both thought and sensory perception." ], [ "Measurement", "Current can be measured using an ammeter.Electric current can be directly measured with a galvanometer, but this method involves breaking the electrical circuit, which is sometimes inconvenient.", "Current can also be measured without breaking the circuit by detecting the magnetic field associated with the current.", "Devices, at the circuit level, use various techniques to measure current:* Shunt resistors* Hall effect current sensor transducers* Transformers (however DC cannot be measured)* Magnetoresistive field sensors* Rogowski coils* Current clamps" ], [ "Resistive heating", "Joule heating, also known as ''ohmic heating'' and ''resistive heating'', is the process of power dissipation by which the passage of an electric current through a conductor increases the internal energy of the conductor, converting thermodynamic work into heat.", "The phenomenon was first studied by James Prescott Joule in 1841.Joule immersed a length of wire in a fixed mass of water and measured the temperature rise due to a known current through the wire for a 30 minute period.", "By varying the current and the length of the wire he deduced that the heat produced was proportional to the square of the current multiplied by the electrical resistance of the wire.This relationship is known as Joule's Law.", "The SI unit of energy was subsequently named the joule and given the symbol ''J''.", "The commonly known SI unit of power, the watt (symbol: W), is equivalent to one joule per second." ], [ "Electromagnetism", "===Electromagnet===Magnetic field is produced by an electric current in a solenoid.In an electromagnet a coil of wires behaves like a magnet when an electric current flows through it.", "When the current is switched off, the coil loses its magnetism immediately.Electric current produces a magnetic field.", "The magnetic field can be visualized as a pattern of circular field lines surrounding the wire that persists as long as there is current.===Electromagnetic induction===Alternating electric current flows through the solenoid, producing a changing magnetic field.", "This field causes an electric current to flow in the wire loop by electromagnetic induction.Magnetic fields can also be used to make electric currents.", "When a changing magnetic field is applied to a conductor, an electromotive force (EMF) is induced, which starts an electric current, when there is a suitable path.===Radio waves===When an electric current flows in a suitably shaped conductor at radio frequencies, radio waves can be generated.", "These travel at the speed of light and can cause electric currents in distant conductors." ], [ "Conduction mechanisms in various media", "In metallic solids, electric charge flows by means of electrons, from lower to higher electrical potential.", "In other media, any stream of charged objects (ions, for example) may constitute an electric current.", "To provide a definition of current independent of the type of charge carriers, ''conventional current'' is defined as moving in the same direction as the positive charge flow.", "So, in metals where the charge carriers (electrons) are negative, conventional current is in the opposite direction to the overall electron movement.", "In conductors where the charge carriers are positive, conventional current is in the same direction as the charge carriers.In a vacuum, a beam of ions or electrons may be formed.", "In other conductive materials, the electric current is due to the flow of both positively and negatively charged particles at the same time.", "In still others, the current is entirely due to positive charge flow.", "For example, the electric currents in electrolytes are flows of positively and negatively charged ions.", "In a common lead-acid electrochemical cell, electric currents are composed of positive hydronium ions flowing in one direction, and negative sulfate ions flowing in the other.", "Electric currents in sparks or plasma are flows of electrons as well as positive and negative ions.", "In ice and in certain solid electrolytes, the electric current is entirely composed of flowing ions.=== Metals ===In a metal, some of the outer electrons in each atom are not bound to the individual molecules as they are in molecular solids, or in full bands as they are in insulating materials, but are free to move within the metal lattice.", "These conduction electrons can serve as charge carriers, carrying a current.", "Metals are particularly conductive because there are many of these free electrons.", "With no external electric field applied, these electrons move about randomly due to thermal energy but, on average, there is zero net current within the metal.", "At room temperature, the average speed of these random motions is 106 metres per second.", "Given a surface through which a metal wire passes, electrons move in both directions across the surface at an equal rate.", "As George Gamow wrote in his popular science book, ''One, Two, Three...Infinity'' (1947), \"The metallic substances differ from all other materials by the fact that the outer shells of their atoms are bound rather loosely, and often let one of their electrons go free.", "Thus the interior of a metal is filled up with a large number of unattached electrons that travel aimlessly around like a crowd of displaced persons.", "When a metal wire is subjected to electric force applied on its opposite ends, these free electrons rush in the direction of the force, thus forming what we call an electric current.", "\"When a metal wire is connected across the two terminals of a DC voltage source such as a battery, the source places an electric field across the conductor.", "The moment contact is made, the free electrons of the conductor are forced to drift toward the positive terminal under the influence of this field.", "The free electrons are therefore the charge carrier in a typical solid conductor.For a steady flow of charge through a surface, the current ''I'' (in amperes) can be calculated with the following equation:where ''Q'' is the electric charge transferred through the surface over a time ''t''.", "If ''Q'' and ''t'' are measured in coulombs and seconds respectively, ''I'' is in amperes.More generally, electric current can be represented as the rate at which charge flows through a given surface as:===Electrolytes===A proton conductor in a static electric field.Electric currents in electrolytes are flows of electrically charged particles (ions).", "For example, if an electric field is placed across a solution of Na+ and Cl− (and conditions are right) the sodium ions move towards the negative electrode (cathode), while the chloride ions move towards the positive electrode (anode).", "Reactions take place at both electrode surfaces, neutralizing each ion.Water-ice and certain solid electrolytes called proton conductors contain positive hydrogen ions (\"protons\") that are mobile.", "In these materials, electric currents are composed of moving protons, as opposed to the moving electrons in metals.In certain electrolyte mixtures, brightly coloured ions are the moving electric charges.", "The slow progress of the colour makes the current visible.===Gases and plasmas===In air and other ordinary gases below the breakdown field, the dominant source of electrical conduction is via relatively few mobile ions produced by radioactive gases, ultraviolet light, or cosmic rays.", "Since the electrical conductivity is low, gases are dielectrics or insulators.", "However, once the applied electric field approaches the breakdown value, free electrons become sufficiently accelerated by the electric field to create additional free electrons by colliding, and ionizing, neutral gas atoms or molecules in a process called avalanche breakdown.", "The breakdown process forms a plasma that contains enough mobile electrons and positive ions to make it an electrical conductor.", "In the process, it forms a light emitting conductive path, such as a spark, arc or lightning.Plasma is the state of matter where some of the electrons in a gas are stripped or \"ionized\" from their molecules or atoms.", "A plasma can be formed by high temperature, or by application of a high electric or alternating magnetic field as noted above.", "Due to their lower mass, the electrons in a plasma accelerate more quickly in response to an electric field than the heavier positive ions, and hence carry the bulk of the current.", "The free ions recombine to create new chemical compounds (for example, breaking atmospheric oxygen into single oxygen O2 → 2O, which then recombine creating ozone O3).===Vacuum===Since a \"perfect vacuum\" contains no charged particles, it normally behaves as a perfect insulator.", "However, metal electrode surfaces can cause a region of the vacuum to become conductive by injecting free electrons or ions through either field electron emission or thermionic emission.", "Thermionic emission occurs when the thermal energy exceeds the metal's work function, while field electron emission occurs when the electric field at the surface of the metal is high enough to cause tunneling, which results in the ejection of free electrons from the metal into the vacuum.", "Externally heated electrodes are often used to generate an electron cloud as in the filament or indirectly heated cathode of vacuum tubes.", "Cold electrodes can also spontaneously produce electron clouds via thermionic emission when small incandescent regions (called ''cathode spots'' or ''anode spots'') are formed.", "These are incandescent regions of the electrode surface that are created by a localized high current.", "These regions may be initiated by field electron emission, but are then sustained by localized thermionic emission once a vacuum arc forms.", "These small electron-emitting regions can form quite rapidly, even explosively, on a metal surface subjected to a high electrical field.", "Vacuum tubes and sprytrons are some of the electronic switching and amplifying devices based on vacuum conductivity.===Superconductivity===Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature.", "It was discovered by Heike Kamerlingh Onnes on April 8, 1911 in Leiden.", "Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon.", "It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor as it transitions into the superconducting state.", "The occurrence of the Meissner effect indicates that superconductivity cannot be understood simply as the idealization of ''perfect conductivity'' in classical physics.===Semiconductor===In a semiconductor it is sometimes useful to think of the current as due to the flow of positive \"holes\" (the mobile positive charge carriers that are places where the semiconductor crystal is missing a valence electron).", "This is the case in a p-type semiconductor.", "A semiconductor has electrical conductivity intermediate in magnitude between that of a conductor and an insulator.", "This means a conductivity roughly in the range of 10−2 to 104 siemens per centimeter (S⋅cm−1).In the classic crystalline semiconductors, electrons can have energies only within certain bands (i.e.", "ranges of levels of energy).", "Energetically, these bands are located between the energy of the ground state, the state in which electrons are tightly bound to the atomic nuclei of the material, and the free electron energy, the latter describing the energy required for an electron to escape entirely from the material.", "The energy bands each correspond to many discrete quantum states of the electrons, and most of the states with low energy (closer to the nucleus) are occupied, up to a particular band called the ''valence band''.", "Semiconductors and insulators are distinguished from metals because the valence band in any given metal is nearly filled with electrons under usual operating conditions, while very few (semiconductor) or virtually none (insulator) of them are available in the ''conduction band'', the band immediately above the valence band.The ease of exciting electrons in the semiconductor from the valence band to the conduction band depends on the band gap between the bands.", "The size of this energy band gap serves as an arbitrary dividing line (roughly 4 eV) between semiconductors and insulators.With covalent bonds, an electron moves by hopping to a neighboring bond.", "The Pauli exclusion principle requires that the electron be lifted into the higher anti-bonding state of that bond.", "For delocalized states, for example in one dimensionthat is in a nanowire, for every energy there is a state with electrons flowing in one direction and another state with the electrons flowing in the other.", "For a net current to flow, more states for one direction than for the other direction must be occupied.", "For this to occur, energy is required, as in the semiconductor the next higher states lie above the band gap.", "Often this is stated as: full bands do not contribute to the electrical conductivity.", "However, as a semiconductor's temperature rises above absolute zero, there is more energy in the semiconductor to spend on lattice vibration and on exciting electrons into the conduction band.", "The current-carrying electrons in the conduction band are known as ''free electrons'', though they are often simply called ''electrons'' if that is clear in context." ], [ "Current density and Ohm's law", "Current density is the rate at which charge passes through a chosen unit area.", "It is defined as a vector whose magnitude is the current per unit cross-sectional area.", "As discussed in Reference direction, the direction is arbitrary.", "Conventionally, if the moving charges are positive, then the current density has the same sign as the velocity of the charges.", "For negative charges, the sign of the current density is opposite to the velocity of the charges.", "In SI units, current density (symbol: j) is expressed in the SI base units of amperes per square metre.In linear materials such as metals, and under low frequencies, the current density across the conductor surface is uniform.", "In such conditions, Ohm's law states that the current is directly proportional to the potential difference between two ends (across) of that metal (ideal) resistor (or other ohmic device):where is the current, measured in amperes; is the potential difference, measured in volts; and is the resistance, measured in ohms.", "For alternating currents, especially at higher frequencies, skin effect causes the current to spread unevenly across the conductor cross-section, with higher density near the surface, thus increasing the apparent resistance." ], [ "Drift speed", "The mobile charged particles within a conductor move constantly in random directions, like the particles of a gas.", "(More accurately, a Fermi gas.)", "To create a net flow of charge, the particles must also move together with an average drift rate.", "Electrons are the charge carriers in most metals and they follow an erratic path, bouncing from atom to atom, but generally drifting in the opposite direction of the electric field.", "The speed they drift at can be calculated from the equation:where* is the electric current* is number of charged particles per unit volume (or charge carrier density)* is the cross-sectional area of the conductor* is the drift velocity, and* is the charge on each particle.Typically, electric charges in solids flow slowly.", "For example, in a copper wire of cross-section 0.5 mm2, carrying a current of 5 A, the drift velocity of the electrons is on the order of a millimetre per second.", "To take a different example, in the near-vacuum inside a cathode-ray tube, the electrons travel in near-straight lines at about a tenth of the speed of light.Any accelerating electric charge, and therefore any changing electric current, gives rise to an electromagnetic wave that propagates at very high speed outside the surface of the conductor.", "This speed is usually a significant fraction of the speed of light, as can be deduced from Maxwell's equations, and is therefore many times faster than the drift velocity of the electrons.", "For example, in AC power lines, the waves of electromagnetic energy propagate through the space between the wires, moving from a source to a distant load, even though the electrons in the wires only move back and forth over a tiny distance.The ratio of the speed of the electromagnetic wave to the speed of light in free space is called the velocity factor, and depends on the electromagnetic properties of the conductor and the insulating materials surrounding it, and on their shape and size.The magnitudes (not the natures) of these three velocities can be illustrated by an analogy with the three similar velocities associated with gases.", "(See also hydraulic analogy.", ")* The low drift velocity of charge carriers is analogous to air motion; in other words, winds.", "* The high speed of electromagnetic waves is roughly analogous to the speed of sound in a gas (sound waves move through air much faster than large-scale motions such as convection)* The random motion of charges is analogous to heatthe thermal velocity of randomly vibrating gas particles." ], [ "See also", "* Current density* Displacement current (electric) and * Electric shock* Electrical measurements* History of electrical engineering* Polarity symbols* International System of Quantities* SI electromagnetism units* Single-phase electric power* Static electricity* Three-phase electric power* Two-phase electric power" ], [ "Notes" ], [ "References" ] ]
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[ [ "Charles Ancillon" ], [ "Introduction", "'''Charles Ancillon''' (28 July 16595 July 1715) was a French jurist and diplomat." ], [ "Life", "Ancillon was born in Metz into a distinguished family of Huguenots.", "His father, David Ancillon (1617–1692), was obliged to leave France on the revocation of the Edict of Nantes, and became pastor of the French Protestant community in Berlin.Ancillon studied law at Marburg, Geneva and Paris, where he was called to the bar.", "At the request of the Huguenots at Metz, he pleaded its cause at the court of King Louis XIV, urging that it should be excepted in the revocation of the Edict of Nantes, but his efforts were unsuccessful, and he joined his father in Berlin.", "He was at once appointed by Elector Frederick III \"''juge et directeur de colonie de Berlin''.\"", "He also became the first headmaster of Französisches Gymnasium Berlin.", "Before this, he had published several works on the revocation of the Edict of Nantes and its consequences, but his literary capacity was mediocre, his style stiff and cold, and it was his personal character rather than his reputation as a writer that earned him the confidence of the elector.In 1687 Ancillon was appointed head of the so-called ''Academie des nobles,'' the principal educational establishment of the state; later on, as councillor of embassy, he took part in the negotiations which led to the assumption of the title of \"King in Prussia\" by the elector.", "In 1699 he succeeded Samuel Pufendorf as historiographer to the elector, and the same year replaced his uncle Joseph Ancillon as judge of all the French refugees in the Margraviate of Brandenburg.Ancillon is mainly remembered for what he did for education in Brandenburg-Prussia, and the share he took, in co-operation with Gottfried Leibniz, in founding the Academy of Berlin.", "Of his fairly numerous works the one of the most value is the \"''Histoire de l'etablissement des Francais refugies dans les etats de Brandebourg''\" published in Berlin in 1690." ], [ "Family", "* Friedrich Ancillon, his grandson, a Prussian historian and statesman" ], [ "References" ], [ "External links", "* *" ] ]
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[ [ "Clark Ashton Smith" ], [ "Introduction", "'''Clark Ashton Smith''' (January 13, 1893 – August 14, 1961) was an American writer and artist.", "He achieved early local recognition, largely through the enthusiasm of George Sterling, for traditional verse in the vein of Swinburne.", "As a poet, Smith is grouped with the West Coast Romantics alongside Joaquin Miller, Sterling, and Nora May French and remembered as \"The Last of the Great Romantics\" and \"The Bard of Auburn\".", "Smith's work was praised by his contemporaries.", "H. P. Lovecraft stated that \"in sheer daemonic strangeness and fertility of conception, Clark Ashton Smith is perhaps unexcelled\", and Ray Bradbury said that Smith \"filled my mind with incredible worlds, impossibly beautiful cities, and still more fantastic creatures\".Smith was one of \"the big three of ''Weird Tales'', with Robert E. Howard and H. P. Lovecraft\", though some readers objected to his morbidness and violation of pulp traditions.", "The fantasy writer and critic L. Sprague de Camp said of him that \"nobody since Poe has so loved a well-rotted corpse\".", "Smith was a member of the Lovecraft circle, and his literary friendship with Lovecraft lasted from 1922 until Lovecraft's death in 1937.His work is marked by an extraordinarily rich and ornate vocabulary, a cosmic perspective and a vein of sardonic and sometimes ribald humor.Of his writing style, Smith stated: \"My own conscious ideal has been to delude the reader into accepting an impossibility, or series of impossibilities, by means of a sort of verbal black magic, in the achievement of which I make use of prose-rhythm, metaphor, simile, tone-color, counter-point, and other stylistic resources, like a sort of incantation.\"" ], [ "Biography", "===Early life and education===Smith was born January 13, 1893, in Long Valley, Placer County, California, into a family of English and New England heritage.", "He spent most of his life in the small town of Auburn, California, living in a cabin built by his parents, Fanny and Timeus Smith.", "Smith professed to hate the town's provincialism but rarely left it until he married late in life.His formal education was limited: he suffered from psychological disorders including intense agoraphobia, and although he was accepted to high school after attending eight years of grammar school, his parents decided it was better for him to be taught at home.", "An insatiable reader with an extraordinary eidetic memory, Smith appeared to retain most or all of whatever he read.", "After leaving formal education, he embarked upon a self-directed course of literature, including ''Robinson Crusoe'', ''Gulliver's Travels'', the fairy tales of Hans Christian Andersen and Madame d'Aulnoy, the ''Arabian Nights'' and the poems of Edgar Allan Poe.", "He read an unabridged dictionary word for word, studying not only the definitions of the words but also their etymology.The other main course in Smith's self-education was to read the complete 11th edition of the ''Encyclopædia Britannica'' at least twice.", "Smith later taught himself French and Spanish to translate verse out of those languages, including works by Gérard de Nerval, Paul Verlaine, Amado Nervo, Gustavo Adolfo Bécquer and all but 6 of Charles Baudelaire's 157 poems in ''The Flowers of Evil''.===Early writing ===Smith as depicted in ''Wonder Stories'' in 1930His first literary efforts, at the age of 11, took the form of fairy tales and imitations of the Arabian Nights.", "Later, he wrote long adventure novels dealing with Oriental life.", "By 14 he had already written a short adventure novel called ''The Black Diamonds'' which was lost for years until published in 2002.Another juvenile novel was written in his teenaged years: ''The Sword of Zagan'' (unpublished until 2004).", "Like ''The Black Diamonds'', it uses a medieval, ''Arabian Nights''-like setting, and the ''Arabian Nights'', like the fairy tales of the Brothers Grimm and the works of Edgar Allan Poe, are known to have strongly influenced Smith's early writing, as did William Beckford's ''Vathek''.At age 17, he sold several tales to ''The Black Cat'', a magazine which specialized in unusual tales.", "He also published some tales in the ''Overland Monthly'' in this brief foray into fiction which preceded his poetic career.However, it was primarily poetry that motivated the young Smith and he confined his efforts to poetry for more than a decade.", "In his later youth, Smith made the acquaintance of the San Francisco poet George Sterling through a member of the local Auburn Monday Night Club, where he read several of his poems with considerable success.", "On a month-long visit to Sterling in Carmel, California, Smith was introduced by Sterling to the poetry of Charles Baudelaire.He became Sterling's protégé and Sterling helped him to publish his first volume of poems, ''The Star-Treader and Other Poems'', at the age of 19.Smith received international acclaim for the collection.", "''The Star-Treader'' was received very favorably by American critics, one of whom named Smith \"the Keats of the Pacific\".", "Smith briefly moved among the circle that included Ambrose Bierce and Jack London, but his early fame soon faded away.===Health breakdown period===A little later, Smith's health broke down and for eight years his literary production was intermittent, though he produced his best poetry during this period.", "A small volume, ''Odes and Sonnets'', was brought out in 1918.Smith came into contact with literary figures who would later form part of H.P.", "Lovecraft's circle of correspondents; Smith knew them far earlier than Lovecraft.", "These figures include poet Samuel Loveman and bookman George Kirk.", "It was Smith who in fact later introduced Donald Wandrei to Lovecraft.", "For this reason, it has been suggested that Lovecraft might as well be referred to as a member of a \"Smith\" circle as Smith was a member of a Lovecraft one.In 1920 Smith composed a celebrated long poem in blank verse, ''The Hashish Eater, or The Apocalypse of Evil'' which was published in ''Ebony and Crystal'' (1922).", "This was followed by a fan letter from H. P. Lovecraft, which was the beginning of 15 years of friendship and correspondence.", "With studied playfulness, Smith and Lovecraft borrowed each other's coinages of place names and the names of strange gods for their stories, though so different is Smith's treatment of the Lovecraft theme that it has been dubbed the \"Clark Ashton Smythos.", "\"In 1925 Smith published ''Sandalwood'', which was partly funded by a gift of $50 from Donald Wandrei.", "He wrote little fiction in this period with the exception of some imaginative vignettes or prose poems.", "Smith was poor for most of his life and often did hard manual jobs such as fruit picking and woodcutting to support himself and his parents.", "He was an able cook and made many kinds of wine.", "He also did well digging, typing and journalism, as well as contributing a column to ''The Auburn Journal'' and sometimes worked as its night editor.One of Smith's artistic patrons and frequent correspondents was San Francisco businessman Albert Bender.===Prolific fiction-writing period===At the beginning of the Depression in 1929, with his aged parents' health weakening, Smith resumed fiction writing and turned out more than a hundred short stories between 1929 and 1934, nearly all of which can be classed as weird horror or science fiction.", "Like Lovecraft, he drew upon the nightmares that had plagued him during youthful spells of sickness.", "Brian Stableford has written that the stories written during this brief phase of hectic productivity \"constitute one of the most remarkable oeuvres in imaginative literature\".He published at his own expense a volume containing six of his best stories, ''The Double Shadow and Other Fantasies'', in an edition of 1000 copies printed by the ''Auburn Journal''.", "The theme of much of his work is egotism and its supernatural punishment; his weird fiction is generally macabre in subject matter, gloatingly preoccupied with images of death, decay and abnormality.Most of Smith's weird fiction falls into four series set variously in Hyperborea, Poseidonis, Averoigne and Zothique.", "Hyperborea, which is a lost continent of the Miocene period, and Poseidonis, which is a remnant of Atlantis, are much the same, with a magical culture characterized by bizarreness, cruelty, death and postmortem horrors.", "Averoigne is Smith's version of pre-modern France, comparable to James Branch Cabell's Poictesme.", "Zothique exists millions of years in the future.", "It is \"the last continent of earth, when the sun is dim and tarnished\".", "These tales have been compared to the ''Dying Earth'' sequence of Jack Vance.In 1933 Smith began corresponding with Robert E. Howard, the Texan creator of Conan the Barbarian.", "From 1933 to 1936, Smith, Howard and Lovecraft were the leaders of the Weird Tales school of fiction and corresponded frequently, although they never met.", "The writer of oriental fantasies E. Hoffmann Price is the only man known to have met all three in the flesh.Critic Steve Behrends has suggested that the frequent theme of 'loss' in Smith's fiction (many of his characters attempt to recapture a long-vanished youth, early love, or picturesque past) may reflect Smith's own feeling that his career had suffered a \"fall from grace\":===Mid-late career: return to poetry and sculpture===In September 1935, Smith's mother Fanny died.", "Smith spent the next two years nursing his father through his last illness.", "Timeus died in December 1937.Aged 44, Smith now virtually ceased writing fiction.", "He had been severely affected by several tragedies occurring in a short period of time: Robert E. Howard's death by suicide (1936), Lovecraft's death from cancer (1937) and the deaths of his parents, which left him exhausted.", "As a result, he withdrew from the scene, marking the end of ''Weird Tales''s Golden Age.", "He began sculpting and resumed the writing of poetry.", "However, Smith was visited by many writers at his cabin, including Fritz Leiber, Rah Hoffman, Francis T. Laney and others.In 1942, three years after August Derleth founded Arkham House for the purpose of preserving the work of H.P.", "Lovecraft, Derleth published the first of several major collections of Smith's fiction, ''Out of Space and Time'' (1942).", "This was followed by ''Lost Worlds'' (1944).", "The books sold slowly, went out of print and became costly rarities.", "Derleth published five more volumes of Smith's prose and two of his verse, and at his death in 1971 had a large volume of Smith's poems in press.===Later life, marriage and death===In 1953, Smith suffered a coronary attack.", "Aged 61, he married Carol(yn) Jones Dorman on November 10, 1954.Dorman had much experience in Hollywood and radio public relations.", "After honeymooning at the Smith cabin, they moved to Pacific Grove, California, where he set up a household including her three children from a previous marriage.", "For several years he alternated between the house on Indian Ridge and their house in Pacific Grove.", "Smith having sold most of his father's tract, in 1957 the old house burned – the Smiths believed by arson, others said by accident.Smith now reluctantly did gardening for other residents at Pacific Grove, and grew a goatee.", "He spent much time shopping and walking near the seafront but despite Derleth's badgering, resisted the writing of more fiction.", "In 1961 he suffered a series of strokes and in August 1961 he quietly died in his sleep, aged 68.After Smith's death, Carol remarried (becoming Carolyn Wakefield) and subsequently died of cancer.The poet's ashes were buried beside, or beneath, a boulder to the immediate west of where his childhood home (destroyed by fire in 1957) stood; some were also scattered in a stand of blue oaks near the boulder.", "There was no marker.", "Plaques recognizing Smith have been erected at the Auburn Placer County Library in 1985 and in Bicentennial Park in Auburn in 2003.Bookseller Roy A. Squires was appointed Smith's \"west coast executor\", with Jack L. Chalker as his \"east coast executor\".", "Squires published many letterpress editions of individual Smith poems.Smith's literary estate is represented by his stepson, Prof William Dorman, director of CASiana Literary Enterprises.", "Arkham House owns the copyright to many Smith stories, though some are now in the public domain.For 'posthumous collaborations' of Smith (stories completed by Lin Carter), see the entry on Lin Carter." ], [ "Artistic periods", "While Smith was always an artist who worked in several very different media, it is possible to identify three distinct periods in which one form of art had precedence over the others.===Poetry: until 1925===Smith published most of his volumes of poetry in this period, including the aforementioned ''The Star-Treader and Other Poems'', as well as ''Odes and Sonnets'' (1918), ''Ebony and Crystal'' (1922) and ''Sandalwood'' (1925).", "His long poem ''The Hashish-Eater; Or, the Apocalypse of Evil'' was written in 1920.===Weird fiction: 1926–1935===Strange Tales''.Smith wrote most of his weird fiction and Cthulhu Mythos stories, inspired by H. P. Lovecraft.", "Creatures of his invention include Aforgomon, Rlim-Shaikorth, Mordiggian, Tsathoggua, the wizard Eibon, and various others.", "In an homage to his friend, Lovecraft referred in \"The Whisperer in Darkness\" and \"The Battle That Ended the Century\" (written in collaboration with R. H. Barlow) to an Atlantean high-priest, \"Klarkash-Ton\".Smith's weird stories form several cycles, called after the lands in which they are set: Averoigne, Hyperborea, Mars, Poseidonis, Zothique.", "To some extent Smith was influenced in his vision of such lost worlds by the teachings of Theosophy and the writings of Helena Blavatsky.", "Stories set in Zothique belong to the Dying Earth subgenre.", "Amongst Smith's science fiction tales are stories set on Mars and the invented planet of Xiccarph.His short stories originally appeared in the magazines ''Weird Tales'', ''Strange Tales'', ''Astounding Stories'', ''Stirring Science Stories'' and ''Wonder Stories''.Clark Ashton Smith was the third member of the great triumvirate of ''Weird Tales'', with Lovecraft and Robert E. Howard.Many of Smith's stories were published in six hardcover volumes by August Derleth under his Arkham House imprint.", "For a full bibliography to 1978, see Sidney-Fryer, ''Emperor of Dreams'' (cited below).", "S. T. Joshi is working with other scholars to produce an updated bibliography of Smith's work.A selection of Smith's best-known tales includes:*\"The Last Incantation\" — ''Weird Tales'', June 1930 LW2*\"A Voyage to Sfanomoe\" — ''Weird Tales'', August 1931 LW2*\"The Tale of Satampra Zeiros\" — ''Weird Tales'' November 1931 LW2*\"The Door to Saturn\" — ''Strange Tales'', January 1932 LW2*\"The Planet of the Dead\" — ''Weird Tales'', March 1932 LW2*\"The Gorgon\" — ''Weird Tales'', April 1932 LW2*\"The Letter from Mohaun Los\" (under the title of \"Flight into Super-Time\") — ''Wonder Stories'', August 1932 LW1*\"The Empire of the Necromancers\" — ''Weird Tales'', September 1932 LW1*\"The Hunters from Beyond\" — ''Strange Tales'', October 1932 LW1*\"The Isle of the Torturers\" — ''Weird Tales'', March 1933 LW1*\"The Light from Beyond\" — ''Wonder Stories'', April 1933 LW1*\"The Beast of Averoigne\" — ''Weird Tales'', May 1933 LW1*\"The Holiness of Azedarac\" — ''Weird Tales'', November 1933 LW1*\"The Demon of the Flower\" — ''Astounding Stories'', December 1933 LW2*\"The Death of Malygris\" — ''Weird Tales'', April 1934 LW2*\"The Plutonium Drug\" — ''Amazing Stories'', September 1934 LW2*\"The Seven Geases\" — ''Weird Tales'', October 1934 LW2*\"Xeethra\" — ''Weird Tales'', December 1934 LW1*\"The Flower-Women\" — ''Weird Tales'', May 1935 LW2*\"The Treader of the Dust\" — ''Weird Tales'', August 1935 LW1*\"Necromancy in Naat\" — ''Weird Tales'', July 1936 LW1*\"The Maze of Maal Dweb\" — ''Weird Tales'', October 1938 LW2*\"The Coming of the White Worm\" — ''Stirring Science Stories'', April 1941 LW2===Visual art: 1935–1961===By this time his interest in writing fiction began to lessen and he turned to creating sculptures from soft rock such as soapstone.", "Smith also made hundreds of fantastic paintings and drawings." ], [ "Bibliography", "The authoritative bibliography on Smith's work is S. T. Joshi, David E. Schultz, and Scott Conners' ''Clark Ashton Smith: A Comprehensive Bibliography.''", "NY: Hippocampus Press, 2020.The first Smith bibliography, which focused on his short fiction, was ''The Tales Of Clark Ashton Smith,'' published by Thomas G L Cockcroft in New Zealand in 1951.===Books published in Smith's lifetime===First editionFirst edition*1912: ''The Star-Treader and Other Poems''.", "San Francisco: A.M. Robertson, Nov 1912.100 pages.", "2000 copies.", "Some copies have a frontispiece photo by Bianca Conti; others lack it.", "*1918: ''Odes and Sonnets''.", "San Francisco: The Book Club of California, June 1918.28 pages.", "300 copies.", "*1922: ''Ebony and Crystal: Poems in Verse and Prose''.", "Auburn CA: The Auburn Journal Press, Oct 1925.43 pages.", "Limited to 500 copies signed by Smith.", "Some copies are found with corrections in Smith's hand to typos in the text.", "*1925: ''Sandalwood''.", "Auburn CA: The Auburn Journal Press, Oct 1925.Verse.", "43 pages.", "Limited to 250 (i.e.", "225) numbered copies signed by Smith.", "Some copies are found with corrections in Smith's hand to typos in the text.", "*1933: ''The Double Shadow and Other Fantasies''.", "Auburn, CA: The Auburn Journal Press, 1933.Short stories.", "Limited to 1000 copies in grey paper wrappers.", "*1937: ''Nero and Other Poems''.", "Lakeport CA: The Futile Press, May 1937.24 pages.", "c.250 copies.", "The poems herein were revised by Smith from their first appearances in ''The Star-Treader and Other Poems.''", "Some copies have laid in the three page essay \"The Price of Poetry\", on Smith's verse, by David Warren Ryder, which was printed to accompany the book.", "According to the official Smith bibliography,the volume was also issued with a broadside, \"Outlanders\" - a 1934 sonnet which made its first appearance in print here.", "Roy A. Squires purchased spare sheets of the volume from Groo Beck of Futile Press, sufficient to produce a 'second state' of 13 copies,which was specially bound by Kristina Etchison and published by bookdealer Terence McVicker.", "(This 2nd state not noted in the official bibliography.", ")*1951: ''The Dark Chateau and Other Poems''.", "Sauk City, WI: Arkham House, Dec 1951.63 pages.", "563 copies.", "*1958: ''Spells and Philtres''.", "Sauk City: Arkham House, March 1958.Verse.", "54 pages.", "519 copies.===Books published posthumously===*1962: ''The Hill of Dionysus – A Selection''.", "Pacific Grove, CA: Roy A. Squires and Clyde Beck.", "Verse.", "This volume was prepared while Smith was still living but he died before it could see print.", "It was published 'In memoriam'.", "*1971: ''Selected Poems''.", "Sauk City, WI: Arkham House, Nov 1971.This volume was delivered by the author to Arkham House in December 1949 but remained unpublished until 1971.===Night Shade Books===* ''The Collected Fantasies of Clark Ashton Smith'' 5-volume work*'' Miscellaneous Writings''.", "Originally announced as ''Tales of India and Irony'' (a collection of non-fantasy/science fiction/horror tales, planned to be available only to subscribers of above collection).", "Now commercially available.", "*'' Red World of Polaris'' (complete tales of Captain Volmar)===Hippocampus Press===* ''The Complete Poetry and Translations of Clark Ashton Smith'' (3 vols)* ''The Black Diamonds''.", "A juvenile Oriental fantasy.", "* ''The Last Oblivion: Best Fantastic Poems of Clark Ashton Smith''* ''The Sword of Zagan and Other Writings''.", "Juvenile Oriental fantasy.", "* ''The Shadow of the Unattained: Letters of George Sterling and Clark Ashton Smith''* ''The Freedom of Fantastic Things: Selected Criticism on Clark Ashton Smith''* ''The Hashish-Eater''.", "(2008).", "Edited with notes etc.", "by Donald Sidney-Fryer.", "Introduction by Ron Hilger.", "Includes a CD audio recording of Sidney-Fryer reading \"The Hashish-Eater\" and (on a hidden track) a selection of other poems by Smith.", "* ''The Averoigne Chronicles: The Complete Averoigne Stories of Clark Ashton Smith''* ''Zothique: The Final Cycle by Clark Ashton Smith''===Arkham House===*''Out of Space and Time''*''Lost Worlds''*''Genius Loci and Other Tales''*''The Dark Chateau''*''Spells and Philtres''*''The Abominations of Yondo''*''Tales of Science and Sorcery''*''Poems in Prose''*''Other Dimensions'' (o.o.p.", ")*''Selected Poems''*''The Black Book of Clark Ashton Smith''*''A Rendezvous in Averoigne''*''Selected Letters of Clark Ashton Smith''====Spearman (reprinted from Arkham House)====*''Lost Worlds'' hardcover 1971 *''Out of Space and Time'' 1971 *''Genius Loci and Other Tales'' hardcover 1972 *''The Abominations of Yondo'' 1972 ====Panther (reprinted from Arkham House)====*''Lost Worlds'' (published in 2 volumes, , )*''Genius Loci'' *''The Abominations of Yondo'' *''Other Dimensions'' (published in 2 volumes, , )*''Out of Space and Time'' (published in 2 volumes, , )*''Tales of Science and Sorcery'' ===Ballantine Adult Fantasy series===*''Zothique'' 1970 *''Hyperborea'' 1971 *''Xiccarph'' 1972 *''Poseidonis'' 1973 *''Averoigne'' (reportedly compiled by series editor Lin Carter, but never released)===Roy A. Squires===* Roy A. Squires, California-based bookman and letterpress printer, issued many limited edition pamphlets consisting of individual Smith poems and prose poems during the 1970s.===Wildside Press===*''The Double Shadow''*''The Maker of Gargoyles and Other Stories''*''The White Sybil and Other Stories''===Timescape Books===*''The City of the Singing Flame'' 1981 *''The Last Incantation'' 1982 *''The Monster of the Prophecy'' 1983 ===Gollancz===* ''The Emperor of Dreams''.", "Ed, Stephen Jones.", "2002.An omnibus edition in paperback of Smith's best tales.===Bancroft Library===*''In the Line of the Grotesque and Monstrous.''", "Introduction by D.S.", "Black.", "Berkeley: The Bancroft Library, 2004.Prints the text of three letters by Smith to Samuel Loveman.", "50 copies only printed, in burnt orange wrappers.", "Printed on the Bancroft library's 1856 Albion handpress.===The RAS Press===* ''The Black Abbot of Puthuum''.", "Glendale, CA: The RAS Press, Oct 2007.Limited to 250 numbered copies.", "(This press was founded by Roy.", "A. Squires and is currently run by bookseller Terence McVicker).===HIH Art Studios===*''Shadows Seen and Unseen: Poetry from the Shadows''.", "Edited by Raymond L.F. Johnson and Ardath W. Winterowd and signed by both editors.", "San Jose, CA: HIH Art Studios, 2007.===Penguin Books===*''The Dark Eidolon and Other Fantasies''.", "Ed, S. T. Joshi.", "2014.===Other (essays, letters, etc)===* Smith, Clark Ashton.", "''Planets and Dimensions: Collected Essays''.", "Edited by Charles K. Wolfe.", "Baltimore MD: Mirage Press, 1973.", "* David E. Schultz and S. T. Joshi (eds).", "''The Shadow of the Unattained: The Letters of George Sterling and Clark Ashton Smith'' NY: Hippocampus Press, 2005.", "* David E. Schultz and S. T. Joshi (eds).", "''Dawnward Spire, Lonely Hill: The Letters of H. P. Lovecraft and Clark Ashton Smith.''", "NY: Hippocampus Press, 2017.", "* David E. Schultz and S.T.", "Joshi (eds).", "''Eccentric, Impractical Devils: The Letters of August Derleth and Clark Ashton Smith.''", "NY: Hippocampus Press, 2020.", "* S.T.", "Joshi and David E. Schultz (eds).", "''Born Under Saturn: The Letters of Samuel Loveman and Clark Ashton Smith'' NY: Hippocampus Press, 2021, an expanded edition of Samuel Loveman's ''Out of the Immortal Night'' (2004) Scholars S.T.", "Joshi and David E. Schultz are preparing various additional volumes of Smith's letters to such of his individual correspondents as Donald Wandrei and R. H. Barlow." ], [ "Media adaptations", "===Visual===*\"The Double Shadow\" was filmed by Azathoth Productions, Newcastle, Australia, on Super 8 film in 1975, with a script by Leigh Blackmore.", "*\"The Return of the Sorcerer\" was adapted for an episode of the television series ''Night Gallery'', starring Vincent Price and Bill Bixby.", "*\"The Seed from the Sepulcher\", \"The Vaults of Yoh Vombis\" and \"The Return of the Sorcerer\" were adapted as ten-page comics by Richard Corben, published in DenSaga 1, 2 and 3 respectively (Fantagor Press 1992–1993).", "* \"Mother of Toads\" was adapted as segment one of the six-segment horror anthology film ''The Theatre Bizarre'' (2011).===Audio===* ''Clark Ashton Smith: Live from Auburn: The Elder Tapes''.", "In the late 1950s Smith recorded a number of his poems on the tape-recorder of his friend Robert B.", "Elder.", "Elder chose the 11 poems at random from Smith's books ''The Dark Chateau'' and \"Spells and Philtres\".", "(Elder had first met Smith when reporting on his 1954 wedding to the former Carol Dorman for ''The Auburn Courier'' and they became friends when Smith praised Elder's novel ''Whom the Gods Destroy''.)", "In 1995 Necronomicon Press released the audiocassette ''Clark Ashton Smith: Live from Auburn: The Elder Tapes'', which includes an introduction by Elder and then Smith reading his poems.", "The recording was produced by Wayne Haigh.", "The cassette was accompanied by a booklet featuring a c.1960 photo of Smith and reprints all 11 poems.", "Gahan Wilson provided the cover art for the cassette and booklet.", "The recording has not been released on CD.", "* ''The Hashish-Eater and Other Poems.''", "Nampa, Idaho: Fedogan and Bremer, 2018.Running time 68 mins.", "Includes Donald Sidney-Fryer's readings of \"The Hashish-Eater\" and a selection of other Smith poems, identical to the selection on the CD which accompanied the 2008 Hippocampus Press volume \"The Hashish-Eater\"; here, however, an orchestral soundtrack by Graham Plowman has been added.", "Booklet notes by Ron Hilger." ], [ "See also", "* Cordwainer Smith Rediscovery Award* \"A Wine of Wizardry\"" ], [ "References", "===Citations====== General and cited sources ===* * Herron, Don (October 2000).", "\"Collecting Clark Ashton Smith\".", "''Firsts''.", "* Joshi, S. T. (2008).", "\"Clark Ashton Smith: Beauty Is for the Few,\" chapter 2 in ''Emperors of Dreams: Some Notes on Weird Poetry''.", "Sydney: P'rea Press.", "(pbk) and (hbk).", "* Murray, Will.", "\"The Clark Ashton Smythos\" in Price, Robert M.", "(ed.).", "''The Horror of It All: Encrusted Gems from the Crypt of Cthulhu''.", "Mercer Island WA: Starmont House, 1990.." ], [ "Further reading", "===Bibliographies===* Cockcroft, Thomas G. L. ''The Tales of Clark Ashton Smith: A Bibliography''.", "Lower Hutt, New Zealand: Cockcroft, Nov 1961 (500 copies).", "The first published bibliography on Smith; superseded by Donald Sidney-Fryer's ''Emperor of Dreams'' (1978) – see below.", "* Joshi, S. T., David E. Schultz and Scott Connors.", "''Clark Ashton Smith: A Comprehensive Bibliography.''", "NY: NY: Hippocampus Press, 2020.", "* Sidney-Fryer, Donald.", "''Emperor of Dreams: A Clark Ashton Smith Bibliography''.", "West Kingston, RI: Donald M. Grant Publishers, 1978.A substantial work of scholarship which remains valuable for its critical appreciations but is now over thirty years out of date.", "A quantity of more recent bibliographical information can be found at the Bibliography section of the Eldritch Dark site online (see External Links).", "Both are completely superseded bibliographically by the Joshi, Schultz and Connors bibliography of 2020.===Journals devoted to Smith's life and work===* Behrends, Steve.", "''Klarkash-Ton: The Journal of Smith Studies'' No 1 (June 1988), Cryptic Publications.", "This journal was retitled by the new publisher as from Issue 2, thus the first issue of ''The Dark Eidolon: The Journal of Smith Studies,'' (Necronomicon Press) is numbered \"2\" (it appeared June 1989).", "There were only 3 issues in total.", "No 3 appeared in Dec 2002.", "* Connors, Scott and Ronald S. Hilger (eds).", "''Lost Worlds: The Journal of Clark Ashton Smith Studies'', Seele Brennt Publications.", "Issued annually, five numbers (2003–2008).", "* Morris, Harry O.", "(ed).", "''Nyctalops'' magazine.", "Special Clark Ashton Smith issue, 96 pp.", "(1973)===Essays and standalone critical works===* Behrends, Steve.", "''Clark Ashton Smith''.", "Starmont Reader's Guide 49.Mercer Island, WA: Starmont House, 1990.", "* Behrends, Steve.", "\"The Song of the Necromancer: 'Loss' in Clark Ashton Smith's Fiction.\"", "''Studies in Weird Fiction,'' 1, No 1 (Summer 1986): 3–12.", "* Connors, Scott.", "''The Freedom of Fantastic Things: Selected Criticism on Clark Ashton Smith''.", "NY: Hippocampus Press, 2006.", "* de Camp, L. Sprague.", "\"Sierra Shaman: Clark Ashton Smith,\" in Literary Swordsmen and Sorcerers: The Makers of Heroic Fantasy.", "Sauk City,.", "WI: Arkham House, 1976, 211–12.", "* Fait, Eleanor.", "\"Auburn Artist-Poet Utilizes Native Rock in Sculptures.\".", "''Sacramento Union'' (Dec 21, 1941), 4C.", "* Haefele, John D. \"Far from Time: Clark Ashton Smith, August Derleth, and Arkham House.\"", "''Weird Fiction Review'' No 1 (Fall 2010), 154–189.", "* Hilger, Ronald.", "''One Hundred Years of Klarkash-Ton''.", "Averon Press, 1996.", "* Schultz, David E. and Scott Connors (ed).", "''Selected Letters of Clark Ashton Smith''.", "Sauk City, WI: Arkham House, 2003.", "* Schultz, David E and S.T.", "Joshi.", "''The Shadow of the Unattained: The Letters of George Sterling and Clark Ashton Smith''.", "NY: Hippocampus Press, 2005.", "* Sidney-Fryer, Donald.", "''The Last of the Great Romantic Poets''.", "Albuquerque NM: Silver Scarab Press, 1973.", "* Sidney-Fryer, Donald.", "''Clark Ashton Smith: The Sorcerer Departs''.", "West Hills, CA: Tsathoggua Press, Jan 1997.Dole: Silver Key Press, 2007.An updated/revised version of Sidney-Fryer's essay in the Special CAS Issue of ''Nyctalops'' (see above under Morris).", "An uncredited extract from this work, as \"A Biography of Clark Ashton Smith,\" may be found online at" ], [ "External links", "* The Eldritch Dark – This website contains almost all of Clark Ashton Smith's written work, as well as a comprehensive selection of his art, biographies, a bibliography, a discussion board, readings, fiction tributes and more.", "* Eldonejo 'Mistera Sturno' – A growing collection of authorized translations into Esperanto for free distribution as ebooks.", "* Smith's poem \"A Chant to Sirius\" read by Leigh Blackmore* * * * * * * Clark Ashton Smith: Poems – A collection of Clark Ashton Smith's early poetry.", "* Clark Ashton Smith at the ''Encyclopedia of Science Fiction''* Clark Ashton Smith at the ''Encyclopedia of Fantasy''" ] ]
wikipedia
[ [ "Context-sensitive grammar" ], [ "Introduction", "A '''context-sensitive grammar''' ('''CSG''') is a formal grammar in which the left-hand sides and right-hand sides of any production rules may be surrounded by a context of terminal and nonterminal symbols.", "Context-sensitive grammars are more general than context-free grammars, in the sense that there are languages that can be described by a CSG but not by a context-free grammar.", "Context-sensitive grammars are less general (in the same sense) than unrestricted grammars.", "Thus, CSGs are positioned between context-free and unrestricted grammars in the Chomsky hierarchy.A formal language that can be described by a context-sensitive grammar, or, equivalently, by a noncontracting grammar or a linear bounded automaton, is called a context-sensitive language.", "Some textbooks actually define CSGs as non-contracting, although this is not how Noam Chomsky defined them in 1959.This choice of definition makes no difference in terms of the languages generated (i.e.", "the two definitions are weakly equivalent), but it does make a difference in terms of what grammars are structurally considered context-sensitive; the latter issue was analyzed by Chomsky in 1963.Chomsky introduced context-sensitive grammars as a way to describe the syntax of natural language where it is often the case that a word may or may not be appropriate in a certain place depending on the context.", "Walter Savitch has criticized the terminology \"context-sensitive\" as misleading and proposed \"non-erasing\" as better explaining the distinction between a CSG and an unrestricted grammar.Although it is well known that certain features of languages (e.g.", "cross-serial dependency) are not context-free, it is an open question how much of CSGs' expressive power is needed to capture the context sensitivity found in natural languages.", "Subsequent research in this area has focused on the more computationally tractable mildly context-sensitive languages.", "The syntaxes of some visual programming languages can be described by context-sensitive graph grammars." ], [ "Formal definition", "=== Formal grammar ===Let us notate a formal grammar as , with a set of nonterminal symbols, a set of terminal symbols, a set of production rules, and the start symbol.A string ''directly yields'', or ''directly derives to'', a string , denoted as , if ''v'' can be obtained from ''u'' by an application of some production rule in ''P'', that is, if and , where is a production rule, and is the unaffected left and right part of the string, respectively.More generally, ''u'' is said to ''yield'', or ''derive to'', ''v'', denoted as , if ''v'' can be obtained from ''u'' by repeated application of production rules, that is, if for some ''n'' ≥ 0 and some strings .", "In other words, the relation is the reflexive transitive closure of the relation .The '''language''' of the grammar ''G'' is the set of all terminal-symbol strings derivable from its start symbol, formally: .Derivations that do not end in a string composed of terminal symbols only are possible, but do not contribute to ''L''(''G'').=== Context-sensitive grammar ===A formal grammar is '''context-sensitive''' if each rule in ''P'' is either of the form where is the empty string, or of the form: α''A''β → αγβwith ''A'' ∈ ''N'', , and .The name ''context-sensitive'' is explained by the α and β that form the context of ''A'' and determine whether ''A'' can be replaced with γ or not.By contrast, in a context-free grammar, no context is present: the left hand side of every production rule is just a nonterminal.The string γ is not allowed to be empty.", "Without this restriction, the resulting grammars become equal in power to unrestricted grammars.=== (Weakly) equivalent definitions ===A noncontracting grammar is a grammar in which for any production rule, of the form ''u'' → ''v'', the length of ''u'' is less than or equal to the length of ''v''.Every context-sensitive grammar is noncontracting, while every noncontracting grammar can be converted into an equivalent context-sensitive grammar; the two classes are weakly equivalent.Some authors use the term ''context-sensitive grammar'' to refer to noncontracting grammars in general.The '''left-context'''- and '''right-context'''-sensitive grammars are defined by restricting the rules to just the form α''A'' → αγ and to just ''A''β → γβ, respectively.", "The languages generated by these grammars are also the full class of context-sensitive languages.", "The equivalence was established by Penttonen normal form." ], [ "Examples", "=== ''anbncn'' ===The following context-sensitive grammar, with start symbol ''S'', generates the canonical non-context-free language { ''anbncn'' | ''n'' ≥ 1 } : 1.", "''S''     →     ''a'' ''B'' ''C'' 2.", "''S'' → ''a'' ''S'' ''B'' ''C'' 3.", "''C'' ''B'' → ''C'' ''Z'' 4.", "''C'' ''Z'' → ''W'' ''Z'' 5.", "''W'' ''Z'' → ''W'' ''C'' 6.", "''W'' ''C'' → ''B'' ''C'' 7.", "''a'' ''B'' → ''a'' ''b'' 8.", "''b'' ''B'' → ''b'' ''b'' 9.", "''b'' ''C'' → ''b'' ''c''10.", "''c'' ''C'' → ''c'' ''c''Rules 1 and 2 allow for blowing-up ''S'' to ''a''''n''''BC''(''BC'')''n''−1; rules 3 to 6 allow for successively exchanging each ''CB'' to ''BC'' (four rules are needed for that since a rule ''CB'' → ''BC'' wouldn't fit into the scheme α''A''β → αγβ); rules 7–10 allow replacing a non-terminals ''B'' and ''C'' with its corresponding terminals ''b'' and ''c'' respectively, provided it is in the right place.A generation chain for '''' is:: ''S'': →2 : →2 : →1 : →3 : →4 : →5 : →6 : →3 : →4 : →5 : →6 : →3 : →4 : →5 : →6 : →7 : →8 : →8 : →9 : →10 : →10 :=== ''anbncndn'', etc.", "===More complicated grammars can be used to parse { ''anbncndn'' | ''n'' ≥ 1 }, and other languages with even more letters.", "Here we show a simpler approach using non-contracting grammars:Start with a kernel of regular productions generating the sentential forms and then include the non contracting productions,,,,,,,,,.=== ''ambncmdn'' ===A non contracting grammar (for which there is an equivalent CSG) for the language is defined by:,:,:,:,:, :, :, and:.With these definitions, a derivation for is:.=== ''a''2''i'' ===A noncontracting grammar for the language { ''a''2''i'' | ''i'' ≥ 1 } is constructed in Example 9.5 (p. 224) of (Hopcroft, Ullman, 1979):# # # # # # # #" ], [ "Kuroda normal form", "Every context-sensitive grammar which does not generate the empty string can be transformed into a weakly equivalent one in Kuroda normal form.", "\"Weakly equivalent\" here means that the two grammars generate the same language.", "The normal form will not in general be context-sensitive, but will be a noncontracting grammar.The Kuroda normal form is an actual normal form for non-contracting grammars." ], [ "Properties and uses", "=== Equivalence to linear bounded automaton ===A formal language can be described by a context-sensitive grammar if and only if it is accepted by some linear bounded automaton (LBA).", "In some textbooks this result is attributed solely to Landweber and Kuroda.", "Others call it the Myhill–Landweber–Kuroda theorem.", "(Myhill introduced the concept of deterministic LBA in 1960.Peter S. Landweber published in 1963 that the language accepted by a deterministic LBA is context sensitive.", "Kuroda introduced the notion of non-deterministic LBA and the equivalence between LBA and CSGs in 1964.)", "it is still an open question whether every context-sensitive language can be accepted by a ''deterministic'' LBA.=== Closure properties ===Context-sensitive languages are closed under complement.", "This 1988 result is known as the Immerman–Szelepcsényi theorem.Moreover, they are closed under union, intersection, concatenation, substitution, inverse homomorphism, and Kleene plus.Every recursively enumerable language ''L'' can be written as ''h''(''L'') for some context-sensitive language ''L'' and some string homomorphism ''h''.=== Computational problems ===The decision problem that asks whether a certain string ''s'' belongs to the language of a given context-sensitive grammar ''G'', is PSPACE-complete.", "Moreover, there are context-sensitive grammars whose languages are PSPACE-complete.", "In other words, there is a context-sensitive grammar ''G'' such that deciding whether a certain string ''s'' belongs to the language of ''G'' is PSPACE-complete (so ''G'' is fixed and only ''s'' is part of the input of the problem).The emptiness problem for context-sensitive grammars (given a context-sensitive grammar ''G'', is ''L''(''G'')=∅ ?)", "is undecidable.=== As model of natural languages ===Savitch has proven the following theoretical result, on which he bases his criticism of CSGs as basis for natural language: for any recursively enumerable set ''R'', there exists a context-sensitive language/grammar ''G'' which can be used as a sort of proxy to test membership in ''R'' in the following way: given a string ''s'', ''s'' is in ''R'' if and only if there exists a positive integer ''n'' for which ''scn'' is in G, where ''c'' is an arbitrary symbol not part of ''R''.It has been shown that nearly all natural languages may in general be characterized by context-sensitive grammars, but the whole class of CSGs seems to be much bigger than natural languages.", "Worse yet, since the aforementioned decision problem for CSGs is PSPACE-complete, that makes them totally unworkable for practical use, as a polynomial-time algorithm for a PSPACE-complete problem would imply P=NP.It was proven that some natural languages are not context-free, based on identifying so-called cross-serial dependencies and unbounded scrambling phenomena.", "However this does not necessarily imply that the class of CSGs is necessary to capture \"context sensitivity\" in the colloquial sense of these terms in natural languages.", "For example, linear context-free rewriting systems (LCFRSs) are strictly weaker than CSGs but can account for the phenomenon of cross-serial dependencies; one can write a LCFRS grammar for {''anbncndn'' | ''n'' ≥ 1} for example.Ongoing research on computational linguistics has focused on formulating other classes of languages that are \"mildly context-sensitive\" whose decision problems are feasible, such as tree-adjoining grammars, combinatory categorial grammars, coupled context-free languages, and linear context-free rewriting systems.", "The languages generated by these formalisms properly lie between the context-free and context-sensitive languages.More recently, the class PTIME has been identified with range concatenation grammars, which are now considered to be the most expressive of the mild-context sensitive language classes." ], [ "See also", "* Chomsky hierarchy* Growing context-sensitive grammar* Definite clause grammar#Non-context-free grammars* List of parser generators for context-sensitive grammars" ], [ "Notes" ], [ "References" ], [ "Further reading", "*" ], [ "External links", "* Earley Parsing for Context-Sensitive Grammars" ] ]
wikipedia
[ [ "Context-sensitive language" ], [ "Introduction", "In formal language theory, a '''context-sensitive language''' is a language that can be defined by a context-sensitive grammar (and equivalently by a noncontracting grammar).", "Context-sensitive is one of the four types of grammars in the Chomsky hierarchy." ], [ "Computational properties", "Computationally, a context-sensitive language is equivalent to a linear bounded nondeterministic Turing machine, also called a linear bounded automaton.", "That is a non-deterministic Turing machine with a tape of only cells, where is the size of the input and is a constant associated with the machine.", "This means that every formal language that can be decided by such a machine is a context-sensitive language, and every context-sensitive language can be decided by such a machine.This set of languages is also known as '''NLINSPACE''' or '''NSPACE'''(''O''(''n'')), because they can be accepted using linear space on a non-deterministic Turing machine.", "The class '''LINSPACE''' (or '''DSPACE'''(''O''(''n''))) is defined the same, except using a deterministic Turing machine.", "Clearly '''LINSPACE''' is a subset of '''NLINSPACE''', but it is not known whether '''LINSPACE''' = '''NLINSPACE'''." ], [ "Examples", "One of the simplest context-sensitive but not context-free languages is : the language of all strings consisting of occurrences of the symbol \"a\", then \"b\"s, then \"c\"s (abc, , , etc.).", "A superset of this language, called the Bach language, is defined as the set of all strings where \"a\", \"b\" and \"c\" (or any other set of three symbols) occurs equally often (, , etc.)", "and is also context-sensitive.", "can be shown to be a context-sensitive language by constructing a linear bounded automaton which accepts .", "The language can easily be shown to be neither regular nor context-free by applying the respective pumping lemmas for each of the language classes to .Similarly: is another context-sensitive language; the corresponding context-sensitive grammar can be easily projected starting with two context-free grammars generating sentential forms in the formatsandand then supplementing them with a permutation production like , a new starting symbol and standard syntactic sugar.", "is another context-sensitive language (the \"3\" in the name of this language is intended to mean a ternary alphabet); that is, the \"product\" operation defines a context-sensitive language (but the \"sum\" defines only a context-free language as the grammar and shows).", "Because of the commutative property of the product, the most intuitive grammar for is ambiguous.", "This problem can be avoided considering a somehow more restrictive definition of the language, e.g.", ".", "This can be specialized to and, from this, to , , etc.", "is a context-sensitive language.", "The corresponding context-sensitive grammar can be obtained as a generalization of the context-sensitive grammars for , , etc.", "is a context-sensitive language.", "is a context-sensitive language (the \"2\" in the name of this language is intended to mean a binary alphabet).", "This was proved by Hartmanis using pumping lemmas for regular and context-free languages over a binary alphabet and, after that, sketching a linear bounded multitape automaton accepting .", "is a context-sensitive language (the \"1\" in the name of this language is intended to mean an unary alphabet).", "This was credited by A. Salomaa to Matti Soittola by means of a linear bounded automaton over an unary alphabet (pages 213-214, exercise 6.8) and also to Marti Penttonen by means of a context-sensitive grammar also over an unary alphabet (See: Formal Languages by A. Salomaa, page 14, Example 2.5).An example of recursive language that is not context-sensitive is any recursive language whose decision is an EXPSPACE-hard problem, say, the set of pairs of equivalent regular expressions with exponentiation." ], [ "Properties of context-sensitive languages", "* The union, intersection, concatenation of two context-sensitive languages is context-sensitive, also the Kleene plus of a context-sensitive language is context-sensitive.", "* The complement of a context-sensitive language is itself context-sensitive a result known as the Immerman–Szelepcsényi theorem.", "* Membership of a string in a language defined by an arbitrary context-sensitive grammar, or by an arbitrary deterministic context-sensitive grammar, is a PSPACE-complete problem." ], [ "See also", "* Linear bounded automaton* List of parser generators for context-sensitive languages* Chomsky hierarchy* Indexed languages – a strict subset of the context-sensitive languages* Weir hierarchy" ], [ "References", "* Sipser, M. (1996), ''Introduction to the Theory of Computation'', PWS Publishing Co." ] ]
wikipedia
[ [ "Chinese room" ], [ "Introduction", "The '''Chinese room argument''' holds that a digital computer executing a program cannot have a \"mind\", \"understanding\", or \"consciousness\", regardless of how intelligently or human-like the program may make the computer behave.", "The argument was presented by philosopher John Searle in his paper \"Minds, Brains, and Programs\", published in ''Behavioral and Brain Sciences'' in 1980.Similar arguments were presented by Gottfried Leibniz (1714), Anatoly Dneprov (1961), Lawrence Davis (1974) and Ned Block (1978).", "Searle's version has been widely discussed in the years since.", "The centerpiece of Searle's argument is a thought experiment known as the '''Chinese room'''.The argument is directed against the philosophical positions of functionalism and computationalism which hold that the mind may be viewed as an information-processing system operating on formal symbols, and that simulation of a given mental state is sufficient for its presence.", "Specifically, the argument is intended to refute a position Searle calls the '''strong AI hypothesis''': \"The appropriately programmed computer with the right inputs and outputs would thereby have a mind in exactly the same sense human beings have minds.", "\"Although it was originally presented in reaction to the statements of artificial intelligence (AI) researchers, it is not an argument against the goals of mainstream AI research because it does not show a limit in the amount of \"intelligent\" behavior a machine can display.", "The argument applies only to digital computers running programs and does not apply to machines in general." ], [ "Chinese room thought experiment", "Searle's thought experiment begins with this hypothetical premise: suppose that artificial intelligence research has succeeded in constructing a computer that behaves as if it understands Chinese.", "It takes Chinese characters as input and, by following the instructions of a computer program, produces other Chinese characters, which it presents as output.", "Suppose, says Searle, that this computer performs its task so convincingly that it comfortably passes the Turing test: it convinces a human Chinese speaker that the program is itself a live Chinese speaker.", "To all of the questions that the person asks, it makes appropriate responses, such that any Chinese speaker would be convinced that they are talking to another Chinese-speaking human being.The question Searle wants to answer is this: does the machine ''literally'' \"understand\" Chinese?", "Or is it merely ''simulating'' the ability to understand Chinese?", "Searle calls the first position \"strong AI\" and the latter \"weak AI\".Searle then supposes that he is in a closed room and has a book with an English version of the computer program, along with sufficient papers, pencils, erasers, and filing cabinets.", "Searle could receive Chinese characters through a slot in the door, process them according to the program's instructions, and produce Chinese characters as output, without understanding any of the content of the Chinese writing.", "If the computer had passed the Turing test this way, it follows, says Searle, that he would do so as well, simply by running the program manually.Searle asserts that there is no essential difference between the roles of the computer and himself in the experiment.", "Each simply follows a program, step-by-step, producing behavior that is then interpreted by the user as demonstrating intelligent conversation.", "However, Searle himself would not be able to understand the conversation.", "(\"I don't speak a word of Chinese\", he points out.)", "Therefore, he argues, it follows that the computer would not be able to understand the conversation either.Searle argues that, without \"understanding\" (or \"intentionality\"), we cannot describe what the machine is doing as \"thinking\" and, since it does not think, it does not have a \"mind\" in anything like the normal sense of the word.", "Therefore, he concludes that the \"strong AI\" hypothesis is false." ], [ "History", "Gottfried Leibniz made a similar argument in 1714 against mechanism (the idea that everything that makes up a human being could, in principle, be explained in mechanical terms.", "In other words that a person, including their mind, is merely a very complex machine).", "Leibniz used the thought experiment of expanding the brain until it was the size of a mill.", "Leibniz found it difficult to imagine that a \"mind\" capable of \"perception\" could be constructed using only mechanical processes.", "Soviet cyberneticist Anatoly Dneprov made an essentially identical argument in 1961, in the form of the short story \"The Game\".", "In it, a stadium of people act as switches and memory cells implementing a program to translate a sentence of Portuguese, a language that none of them know.", "The game was organized by a \"Professor Zarubin\" to answer the question \"Can mathematical machines think?\"", "Speaking through Zarubin, Dneprov writes \"the only way to prove that machines can think is to turn yourself into a machine and examine your thinking process\" and he concludes, as Searle does, \"We've proven that even the most perfect simulation of machine thinking is not the thinking process itself.\"", "In 1974, Lawrence Davis imagined duplicating the brain using telephone lines and offices staffed by people, and in 1978 Ned Block envisioned the entire population of China involved in such a brain simulation.", "This thought experiment is called the China brain, also the \"Chinese Nation\" or the \"Chinese Gym\".", "John Searle in December 2005Searle's version appeared in his 1980 paper \"Minds, Brains, and Programs\", published in ''Behavioral and Brain Sciences''.", "It eventually became the journal's \"most influential target article\", generating an enormous number of commentaries and responses in the ensuing decades, and Searle has continued to defend and refine the argument in many papers, popular articles and books.", "David Cole writes that \"the Chinese Room argument has probably been the most widely discussed philosophical argument in cognitive science to appear in the past 25 years\".Most of the discussion consists of attempts to refute it.", "\"The overwhelming majority\", notes ''BBS'' editor Stevan Harnad, \"still think that the Chinese Room Argument is dead wrong\".", "The sheer volume of the literature that has grown up around it inspired Pat Hayes to comment that the field of cognitive science ought to be redefined as \"the ongoing research program of showing Searle's Chinese Room Argument to be false\".Searle's argument has become \"something of a classic in cognitive science\", according to Harnad.", "Varol Akman agrees, and has described the original paper as \"an exemplar of philosophical clarity and purity\"." ], [ "Philosophy", "Although the Chinese Room argument was originally presented in reaction to the statements of artificial intelligence researchers, philosophers have come to consider it as an important part of the philosophy of mind.", "It is a challenge to functionalism and the computational theory of mind, and is related to such questions as the mind–body problem, the problem of other minds, the symbol-grounding problem, and the hard problem of consciousness.===Strong AI===Searle identified a philosophical position he calls \"strong AI\":The definition depends on the distinction between ''simulating'' a mind and ''actually having'' a mind.", "Searle writes that \"according to Strong AI, the correct simulation really is a mind.", "According to Weak AI, the correct simulation is a model of the mind.", "\"The claim is implicit in some of the statements of early AI researchers and analysts.", "For example, in 1955, AI founder Herbert A. Simon declared that \"there are now in the world machines that think, that learn and create\".", "Simon, together with Allen Newell and Cliff Shaw, after having completed the first \"AI\" program, the Logic Theorist, claimed that they had \"solved the venerable mind–body problem, explaining how a system composed of matter can have the properties of mind.\"", "John Haugeland wrote that \"AI wants only the genuine article: ''machines with minds'', in the full and literal sense.", "This is not science fiction, but real science, based on a theoretical conception as deep as it is daring: namely, we are, at root, ''computers ourselves''.", "\"Searle also ascribes the following claims to advocates of strong AI:* AI systems can be used to explain the mind;* The study of the brain is irrelevant to the study of the mind; and* The Turing test is adequate for establishing the existence of mental states.===Strong AI as computationalism or functionalism===In more recent presentations of the Chinese room argument, Searle has identified \"strong AI\" as \"computer functionalism\" (a term he attributes to Daniel Dennett).", "Functionalism is a position in modern philosophy of mind that holds that we can define mental phenomena (such as beliefs, desires, and perceptions) by describing their functions in relation to each other and to the outside world.", "Because a computer program can accurately represent functional relationships as relationships between symbols, a computer can have mental phenomena if it runs the right program, according to functionalism.Stevan Harnad argues that Searle's depictions of strong AI can be reformulated as \"recognizable tenets of ''computationalism'', a position (unlike \"strong AI\") that is actually held by many thinkers, and hence one worth refuting.\"", "Computationalism is the position in the philosophy of mind which argues that the mind can be accurately described as an information-processing system.Each of the following, according to Harnad, is a \"tenet\" of computationalism:* Mental states are computational states (which is why computers can have mental states and help to explain the mind);* Computational states are implementation-independent—in other words, it is the software that determines the computational state, not the hardware (which is why the brain, being hardware, is irrelevant); and that* Since implementation is unimportant, the only empirical data that matters is how the system functions; hence the Turing test is definitive.===Strong AI vs. biological naturalism===Searle holds a philosophical position he calls \"biological naturalism\": that consciousness and understanding require specific biological machinery that are found in brains.", "He writes \"brains cause minds\" and that \"actual human mental phenomena are dependent on actual physical–chemical properties of actual human brains\".", "Searle argues that this machinery (known to neuroscience as the \"neural correlates of consciousness\") must have some causal powers that permit the human experience of consciousness.", "Searle's belief in the existence of these powers has been criticized.Searle does not disagree with the notion that machines can have consciousness and understanding, because, as he writes, \"we are precisely such machines\".", "Searle holds that the brain is, in fact, a machine, but that the brain gives rise to consciousness and understanding using specific machinery.", "If neuroscience is able to isolate the mechanical process that gives rise to consciousness, then Searle grants that it may be possible to create machines that have consciousness and understanding.", "However, without the specific machinery required, Searle does not believe that consciousness can occur.Biological naturalism implies that one cannot determine if the experience of consciousness is occurring merely by examining how a system functions, because the specific machinery of the brain is essential.", "Thus, biological naturalism is directly opposed to both behaviorism and functionalism (including \"computer functionalism\" or \"strong AI\").", "Biological naturalism is similar to identity theory (the position that mental states are \"identical to\" or \"composed of\" neurological events); however, Searle has specific technical objections to identity theory.", "Searle's biological naturalism and strong AI are both opposed to Cartesian dualism, the classical idea that the brain and mind are made of different \"substances\".", "Indeed, Searle accuses strong AI of dualism, writing that \"strong AI only makes sense given the dualistic assumption that, where the mind is concerned, the brain doesn't matter.", "\"===Consciousness===Searle's original presentation emphasized \"understanding\"—that is, mental states with what philosophers call \"intentionality\"—and did not directly address other closely related ideas such as \"consciousness\".", "However, in more recent presentations, Searle has included consciousness as the real target of the argument.David Chalmers writes, \"it is fairly clear that consciousness is at the root of the matter\" of the Chinese room.Colin McGinn argues that the Chinese room provides strong evidence that the hard problem of consciousness is fundamentally insoluble.", "The argument, to be clear, is not about whether a machine can be conscious, but about whether it (or anything else for that matter) can be shown to be conscious.", "It is plain that any other method of probing the occupant of a Chinese room has the same difficulties in principle as exchanging questions and answers in Chinese.", "It is simply not possible to divine whether a conscious agency or some clever simulation inhabits the room.Searle argues that this is only true for an observer ''outside'' of the room.", "The whole point of the thought experiment is to put someone ''inside'' the room, where they can directly observe the operations of consciousness.", "Searle claims that from his vantage point within the room there is nothing he can see that could imaginably give rise to consciousness, other than himself, and clearly he does not have a mind that can speak Chinese.===Applied ethics===a warship—proposed as a real-life analog to the Chinese roomPatrick Hew used the Chinese Room argument to deduce requirements from military command and control systems if they are to preserve a commander's moral agency.", "He drew an analogy between a commander in their command center and the person in the Chinese Room, and analyzed it under a reading of Aristotle's notions of \"compulsory\" and \"ignorance\".", "Information could be \"down converted\" from meaning to symbols, and manipulated symbolically, but moral agency could be undermined if there was inadequate 'up conversion' into meaning.", "Hew cited examples from the USS ''Vincennes'' incident." ], [ "Computer science", "The Chinese room argument is primarily an argument in the philosophy of mind, and both major computer scientists and artificial intelligence researchers consider it irrelevant to their fields.", "However, several concepts developed by computer scientists are essential to understanding the argument, including symbol processing, Turing machines, Turing completeness, and the Turing test.===Strong AI vs. AI research===Searle's arguments are not usually considered an issue for AI research.", "The primary mission of artificial intelligence research is only to create useful systems that ''act'' intelligently and it does not matter if the intelligence is \"merely\" a simulation.", "AI researchers Stuart Russell and Peter Norvig wrote in 2021: \"We are interested in programs that behave intelligently.", "Individual aspects of consciousness -- awareness, self-awareness, attention -- can be programmed and can be part of an intelligent machine.", "The additional project making a machine conscious in exactly the way humans are is not one that we are equipped to take on.", "\"Searle does not disagree that AI research can create machines that are capable of highly intelligent behavior.", "The Chinese room argument leaves open the possibility that a digital machine could be built that ''acts'' more intelligently than a person, but does not have a mind or intentionality in the same way that brains do.Searle's \"strong AI hypothesis\" should not be confused with \"strong AI\" as defined by Ray Kurzweil and other futurists, who use the term to describe machine intelligence that rivals or exceeds human intelligence -- that is, artificial general intelligence, human level AI or superintelligence.", "Kurzweil is referring primarily to the ''amount'' of intelligence displayed by the machine, whereas Searle's argument sets no limit on this.", "Searle argues that a superintelligent machine would not necessarily have a mind and consciousness.===Turing test===The \"standard interpretation\" of the Turing Test, in which player C, the interrogator, is given the task of trying to determine which player—A or B—is a computer and which is a human.", "The interrogator is limited to using the responses to written questions to make the determination.", "Image adapted from Saygin, et al.", "2000.The Chinese room implements a version of the Turing test.", "Alan Turing introduced the test in 1950 to help answer the question \"can machines think?\"", "In the standard version, a human judge engages in a natural language conversation with a human and a machine designed to generate performance indistinguishable from that of a human being.", "All participants are separated from one another.", "If the judge cannot reliably tell the machine from the human, the machine is said to have passed the test.Turing then considered each possible objection to the proposal \"machines can think\", and found that there are simple, obvious answers if the question is de-mystified in this way.", "He did not, however, intend for the test to measure for the presence of \"consciousness\" or \"understanding\".", "He did not believe this was relevant to the issues that he was addressing.", "He wrote:To Searle, as a philosopher investigating in the nature of mind and consciousness, these are the relevant mysteries.", "The Chinese room is designed to show that the Turing test is insufficient to detect the presence of consciousness, even if the room can behave or function as a conscious mind would.===Symbol processing===The Chinese room (and all modern computers) manipulate physical objects in order to carry out calculations and do simulations.", "AI researchers Allen Newell and Herbert A. Simon called this kind of machine a physical symbol system.", "It is also equivalent to the formal systems used in the field of mathematical logic.Searle emphasizes the fact that this kind of symbol manipulation is syntactic (borrowing a term from the study of grammar).", "The computer manipulates the symbols using a form of syntax rules, without any knowledge of the symbol's semantics (that is, their meaning).Newell and Simon had conjectured that a physical symbol system (such as a digital computer) had all the necessary machinery for \"general intelligent action\", or, as it is known today, artificial general intelligence.", "They framed this as a philosophical position, the physical symbol system hypothesis: \"A physical symbol system has the necessary and sufficient means for general intelligent action.\"", "The Chinese room argument does not refute this, because it is framed in terms of \"intelligent action\", i.e.", "the external behavior of the machine, rather than the presence or absence of understanding, consciousness and mind.Twenty-first century AI programs (such as \"deep learning\") do mathematical operations on huge matrixes of unidentified numbers and bear little resemblance to the symbolic processing used by AI programs at the time Searle wrote his critique in 1980.Nils Nilsson describes systems like these as \"dynamic\" rather than \"symbolic\".", "Nilsson notes that these are essentially digitized representations of ''dynamic'' systems -- the individual numbers do not have a specific semantics, but are instead samples or data points from a dynamic signal, and it is the signal being approximated which would have semantics.", "Nilsson argues it is not reasonable to consider these signals as \"symbol processing\" in the same sense as the physical symbol systems hypothesis.===Chinese room and Turing completeness===The Chinese room has a design analogous to that of a modern computer.", "It has a Von Neumann architecture, which consists of a program (the book of instructions), some memory (the papers and file cabinets), a CPU that follows the instructions (the man), and a means to write symbols in memory (the pencil and eraser).", "A machine with this design is known in theoretical computer science as \"Turing complete\", because it has the necessary machinery to carry out any computation that a Turing machine can do, and therefore it is capable of doing a step-by-step simulation of any other digital machine, given enough memory and time.", "Alan Turing writes, \"all digital computers are in a sense equivalent.\"", "The widely accepted Church–Turing thesis holds that any function computable by an effective procedure is computable by a Turing machine.The Turing completeness of the Chinese room implies that it can do whatever any other digital computer can do (albeit much, much more slowly).", "Thus, if the Chinese room does not or can not contain a Chinese-speaking mind, then no other digital computer can contain a mind.", "Some replies to Searle begin by arguing that the room, as described, cannot have a Chinese-speaking mind.", "Arguments of this form, according to Stevan Harnad, are \"no refutation (but rather an affirmation)\" of the Chinese room argument, because these arguments actually imply that ''no'' digital computers can have a mind.There are some critics, such as Hanoch Ben-Yami, who argue that the Chinese room cannot simulate all the abilities of a digital computer, such as being able to determine the current time." ], [ "Complete argument", "Searle has produced a more formal version of the argument of which the Chinese Room forms a part.", "He presented the first version in 1984.The version given below is from 1990.The Chinese room thought experiment is intended to prove point A3.He begins with three axioms::(A1) \"Programs are formal (syntactic).", "\"::A program uses syntax to manipulate symbols and pays no attention to the semantics of the symbols.", "It knows where to put the symbols and how to move them around, but it does not know what they stand for or what they mean.", "For the program, the symbols are just physical objects like any others.", ":(A2) \"Minds have mental contents (semantics).", "\"::Unlike the symbols used by a program, our thoughts have meaning: they represent things and we know what it is they represent.", ":(A3) \"Syntax by itself is neither constitutive of nor sufficient for semantics.", "\"::This is what the Chinese room thought experiment is intended to prove: the Chinese room has syntax (because there is a man in there moving symbols around).", "The Chinese room has no semantics (because, according to Searle, there is no one or nothing in the room that understands what the symbols mean).", "Therefore, having syntax is not enough to generate semantics.Searle posits that these lead directly to this conclusion::(C1) Programs are neither constitutive of nor sufficient for minds.", "::This should follow without controversy from the first three: Programs don't have semantics.", "Programs have only syntax, and syntax is insufficient for semantics.", "Every mind has semantics.", "Therefore no programs are minds.This much of the argument is intended to show that artificial intelligence can never produce a machine with a mind by writing programs that manipulate symbols.", "The remainder of the argument addresses a different issue.", "Is the human brain running a program?", "In other words, is the computational theory of mind correct?", "He begins with an axiom that is intended to express the basic modern scientific consensus about brains and minds::(A4) Brains cause minds.Searle claims that we can derive \"immediately\" and \"trivially\" that::(C2) Any other system capable of causing minds would have to have causal powers (at least) equivalent to those of brains.", "::Brains must have something that causes a mind to exist.", "Science has yet to determine exactly what it is, but it must exist, because minds exist.", "Searle calls it \"causal powers\".", "\"Causal powers\" is whatever the brain uses to create a mind.", "If anything else can cause a mind to exist, it must have \"equivalent causal powers\".", "\"Equivalent causal powers\" is whatever ''else'' that could be used to make a mind.And from this he derives the further conclusions::(C3) Any artifact that produced mental phenomena, any artificial brain, would have to be able to duplicate the specific causal powers of brains, and it could not do that just by running a formal program.", "::This follows from C1 and C2: Since no program can produce a mind, and \"equivalent causal powers\" produce minds, it follows that programs do not have \"equivalent causal powers.", "\":(C4) The way that human brains actually produce mental phenomena cannot be solely by virtue of running a computer program.", "::Since programs do not have \"equivalent causal powers\", \"equivalent causal powers\" produce minds, and brains produce minds, it follows that brains do not use programs to produce minds.Refutations of Searle's argument take many different forms (see below).", "Computationalists and functionalists reject A3, arguing that \"syntax\" (as Searle describes it) ''can'' have \"semantics\" if the syntax has the right functional structure.", "Eliminative materialists reject A2, arguing that minds don't actually have \"semantics\" -- that thoughts and other mental phenomena are inherently meaningless but nevertheless function as if they had meaning." ], [ "Replies", "Replies to Searle's argument may be classified according to what they claim to show:* Those which identify ''who'' speaks Chinese* Those which demonstrate how meaningless symbols can become meaningful* Those which suggest that the Chinese room should be redesigned in some way* Those which contend that Searle's argument is misleading* Those which argue that the argument makes false assumptions about subjective conscious experience and therefore proves nothingSome of the arguments (robot and brain simulation, for example) fall into multiple categories.===Systems and virtual mind replies: finding the mind===These replies attempt to answer the question: since the man in the room does not speak Chinese, ''where'' is the \"mind\" that does?", "These replies address the key ontological issues of mind vs. body and simulation vs. reality.", "All of the replies that identify the mind in the room are versions of \"the system reply\".==== System reply ====:The basic version of the system reply argues that it is the \"whole system\" that understands Chinese.", "While the man understands only English, when he is combined with the program, scratch paper, pencils and file cabinets, they form a system that can understand Chinese.", "\"Here, understanding is not being ascribed to the mere individual; rather it is being ascribed to this whole system of which he is a part\" Searle explains.", ":Searle notes that (in this simple version of the reply) the \"system\" is nothing more than a collection of ordinary physical objects; it grants the power of understanding and consciousness to \"the conjunction of that person and bits of paper\" without making any effort to explain how this pile of objects has become a conscious, thinking being.", "Searle argues that no reasonable person should be satisfied with the reply, unless they are \"under the grip of an ideology;\" In order for this reply to be remotely plausible, one must take it for granted that consciousness can be the product of an information processing \"system\", and does not require anything resembling the actual biology of the brain.", ":Searle then responds by simplifying this list of physical objects: he asks what happens if the man memorizes the rules and keeps track of everything in his head?", "Then the whole system consists of just one object: the man himself.", "Searle argues that if the man does not understand Chinese then the system does not understand Chinese either because now \"the system\" and \"the man\" both describe exactly the same object.", ":Critics of Searle's response argue that the program has allowed the man to have two minds in one head.", "If we assume a \"mind\" is a form of information processing, then the theory of computation can account for two computations occurring at once, namely (1) the computation for universal programmability (which is the function instantiated by the person and note-taking materials ''independently'' from any particular program contents) and (2) the computation of the Turing machine that is described by the program (which is instantiated by everything ''including'' the specific program).", "The theory of computation thus formally explains the open possibility that the second computation in the Chinese Room could entail a human-equivalent semantic understanding of the Chinese inputs.", "The focus belongs on the program's Turing machine rather than on the person's.", "However, from Searle's perspective, this argument is circular.", "The question at issue is whether consciousness is a form of information processing, and this reply requires that we make that assumption.More sophisticated versions of the systems reply try to identify more precisely what \"the system\" is and they differ in exactly how they describe it.", "According to these replies, the \"mind that speaks Chinese\" could be such things as: the \"software\", a \"program\", a \"running program\", a simulation of the \"neural correlates of consciousness\", the \"functional system\", a \"simulated mind\", an \"emergent property\", or \"a virtual mind\" (described below).==== Virtual mind reply ====:Marvin Minsky suggested a version of the system reply known as the \"virtual mind reply\".", "The term \"virtual\" is used in computer science to describe an object that appears to exist \"in\" a computer (or computer network) only because software makes it appear to exist.", "The objects \"inside\" computers (including files, folders, and so on) are all \"virtual\", except for the computer's electronic components.", "Similarly, Minsky argues, a computer may contain a \"mind\" that is virtual in the same sense as virtual machines, virtual communities and virtual reality.", ":To clarify the distinction between the simple systems reply given above and virtual mind reply, David Cole notes that two simulations could be running on one system at the same time: one speaking Chinese and one speaking Korean.", "While there is only one system, there can be multiple \"virtual minds,\" thus the \"system\" cannot be the \"mind\".", ":Searle responds that such a mind is, at best, a simulation, and writes: \"No one supposes that computer simulations of a five-alarm fire will burn the neighborhood down or that a computer simulation of a rainstorm will leave us all drenched.\"", "Nicholas Fearn responds that, for some things, simulation is as good as the real thing.", "\"When we call up the pocket calculator function on a desktop computer, the image of a pocket calculator appears on the screen.", "We don't complain that 'it isn't ''really'' a calculator', because the physical attributes of the device do not matter.\"", "The question is, is the human mind like the pocket calculator, essentially composed of information, where a perfect simulation of the thing just ''is'' the thing?", "Or is the mind like the rainstorm, a thing in the world that is more than just its simulation, and not realizable in full by a computer simulation?", "For decades, this question of simulation has led AI researchers and philosophers to consider whether the term \"synthetic intelligence\" is more appropriate than the common description of such intelligences as \"artificial.", "\"These replies provide an explanation of exactly who it is that understands Chinese.", "If there is something ''besides'' the man in the room that can understand Chinese, Searle cannot argue that (1) the man does not understand Chinese, therefore (2) nothing in the room understands Chinese.", "This, according to those who make this reply, shows that Searle's argument fails to prove that \"strong AI\" is false.These replies, by themselves, do not provide any evidence that strong AI is ''true'', however.", "They do not show that the system (or the virtual mind) understands Chinese, other than the hypothetical premise that it passes the Turing Test.", "Searle argues that, if we are to consider Strong AI remotely plausible, the Chinese Room is an example that requires explanation, and it is difficult or impossible to explain how consciousness might \"emerge\" from the room or how the system would have consciousness.", "As Searle writes \"the systems reply simply begs the question by insisting that the system must understand Chinese\" and thus is dodging the question or hopelessly circular.===Robot and semantics replies: finding the meaning===As far as the person in the room is concerned, the symbols are just meaningless \"squiggles.\"", "But if the Chinese room really \"understands\" what it is saying, then the symbols must get their meaning from somewhere.", "These arguments attempt to connect the symbols to the things they symbolize.", "These replies address Searle's concerns about intentionality, symbol grounding and syntax vs. semantics.====Robot reply====:Suppose that instead of a room, the program was placed into a robot that could wander around and interact with its environment.", "This would allow a \"causal connection\" between the symbols and things they represent.", "Hans Moravec comments: \"If we could graft a robot to a reasoning program, we wouldn't need a person to provide the meaning anymore: it would come from the physical world.", "\":Searle's reply is to suppose that, unbeknownst to the individual in the Chinese room, some of the inputs came directly from a camera mounted on a robot, and some of the outputs were used to manipulate the arms and legs of the robot.", "Nevertheless, the person in the room is still just following the rules, and ''does not know what the symbols mean.''", "Searle writes \"he doesn't ''see'' what comes into the robot's eyes.\"", "(See Mary's room for a similar thought experiment.", ")====Derived meaning====: Some respond that the room, as Searle describes it, ''is'' connected to the world: through the Chinese speakers that it is \"talking\" to and through the programmers who designed the knowledge base in his file cabinet.", "The symbols Searle manipulates ''are already meaningful'', they're just not meaningful to ''him''.", ":Searle says that the symbols only have a \"derived\" meaning, like the meaning of words in books.", "The meaning of the symbols depends on the conscious understanding of the Chinese speakers and the programmers outside the room.", "The room, like a book, has no understanding of its own.====Commonsense knowledge / contextualist reply====:Some have argued that the meanings of the symbols would come from a vast \"background\" of commonsense knowledge encoded in the program and the filing cabinets.", "This would provide a \"context\" that would give the symbols their meaning.", ":Searle agrees that this background exists, but he does not agree that it can be built into programs.", "Hubert Dreyfus has also criticized the idea that the \"background\" can be represented symbolically.To each of these suggestions, Searle's response is the same: no matter how much knowledge is written into the program and no matter how the program is connected to the world, he is still in the room manipulating symbols according to rules.", "His actions are syntactic and this can never explain to him what the symbols stand for.", "Searle writes \"syntax is insufficient for semantics.", "\"However, for those who accept that Searle's actions simulate a mind, separate from his own, the important question is not what the symbols mean ''to Searle'', what is important is what they mean ''to the virtual mind.''", "While Searle is trapped in the room, the virtual mind is not: it is connected to the outside world through the Chinese speakers it speaks to, through the programmers who gave it world knowledge, and through the cameras and other sensors that roboticists can supply.===Brain simulation and connectionist replies: redesigning the room===These arguments are all versions of the systems reply that identify a particular ''kind'' of system as being important; they identify some special technology that would create conscious understanding in a machine.", "(The \"robot\" and \"commonsense knowledge\" replies above also specify a certain kind of system as being important.", ")====Brain simulator reply====:Suppose that the program simulated in fine detail the action of every neuron in the brain of a Chinese speaker.", "This strengthens the intuition that there would be no significant difference between the operation of the program and the operation of a live human brain.", ":Searle replies that such a simulation does not reproduce the important features of the brain—its causal and intentional states.", "Searle is adamant that \"human mental phenomena are dependent on actual physical–chemical properties of actual human brains.\"", "Moreover, he argues:Two variations on the brain simulator reply are the China brain and the brain-replacement scenario.=====China brain=====:What if we ask each citizen of China to simulate one neuron, using the telephone system to simulate the connections between axons and dendrites?", "In this version, it seems obvious that no individual would have any understanding of what the brain might be saying.", "It is also obvious that this system would be functionally equivalent to a brain, so if consciousness is a function, this system would be conscious.=====Brain replacement scenario=====:In this, we are asked to imagine that engineers have invented a tiny computer that simulates the action of an individual neuron.", "What would happen if we replaced one neuron at a time?", "Replacing one would clearly do nothing to change conscious awareness.", "Replacing all of them would create a digital computer that simulates a brain.", "If Searle is right, then conscious awareness must disappear during the procedure (either gradually or all at once).", "Searle's critics argue that there would be no point during the procedure when he can claim that conscious awareness ends and mindless simulation begins.", "(See Ship of Theseus for a similar thought experiment.", ")====Connectionist replies====:Closely related to the brain simulator reply, this claims that a massively parallel connectionist architecture would be capable of understanding.", "Modern deep learning is massively parallel and has successfully displayed intelligent behavior in many domains.", "Nils Nilsson argues that modern AI is using digitized \"dynamic signals\" rather than \"symbols\" of the kind used by AI in 1980.Here it is the sampled ''signal'' which would have the semantics, not the individual numbers manipulated by the program.", "This is a different kind of machine than the one that Searle visualized.====Combination reply====:This response combines the robot reply with the brain simulation reply, arguing that a brain simulation connected to the world through a robot body could have a mind.====Many mansions / wait till next year reply====:Better technology in the future will allow computers to understand.", "Searle agrees that this is possible, but considers this point irrelevant.", "Searle agrees that there may be other hardware besides brains that have conscious understanding.These arguments (and the robot or commonsense knowledge replies) identify some special technology that would help create conscious understanding in a machine.", "They may be interpreted in two ways: either they claim (1) this technology is required for consciousness, the Chinese room does not or cannot implement this technology, and therefore the Chinese room cannot pass the Turing test or (even if it did) it would not have conscious understanding.", "Or they may be claiming that (2) it is easier to see that the Chinese room has a mind if we visualize this technology as being used to create it.In the first case, where features like a robot body or a connectionist architecture are required, Searle claims that strong AI (as he understands it) has been abandoned.", "The Chinese room has all the elements of a Turing complete machine, and thus is capable of simulating any digital computation whatsoever.", "If Searle's room cannot pass the Turing test then there is no other digital technology that could pass the Turing test.", "If Searle's room ''could'' pass the Turing test, but still does not have a mind, then the Turing test is not sufficient to determine if the room has a \"mind\".", "Either way, it denies one or the other of the positions Searle thinks of as \"strong AI\", proving his argument.The brain arguments in particular deny strong AI if they assume that there is no simpler way to describe the mind than to create a program that is just as mysterious as the brain was.", "He writes \"I thought the whole idea of strong AI was that we don't need to know how the brain works to know how the mind works.\"", "If computation does not provide an ''explanation'' of the human mind, then strong AI has failed, according to Searle.Other critics hold that the room as Searle described it does, in fact, have a mind, however they argue that it is difficult to see—Searle's description is correct, but ''misleading.''", "By redesigning the room more realistically they hope to make this more obvious.", "In this case, these arguments are being used as appeals to intuition (see next section).In fact, the room can just as easily be redesigned to ''weaken'' our intuitions.", "Ned Block's Blockhead argument suggests that the program could, in theory, be rewritten into a simple lookup table of rules of the form \"if the user writes ''S'', reply with ''P'' and goto X\".", "At least in principle, any program can be rewritten (or \"refactored\") into this form, even a brain simulation.", "In the blockhead scenario, the entire mental state is hidden in the letter X, which represents a memory address—a number associated with the next rule.", "It is hard to visualize that an instant of one's conscious experience can be captured in a single large number, yet this is exactly what \"strong AI\" claims.", "On the other hand, such a lookup table would be ridiculously large (to the point of being physically impossible), and the states could therefore be ''extremely'' specific.Searle argues that however the program is written or however the machine is connected to the world, the mind is being ''simulated'' by a simple step-by-step digital machine (or machines).", "These machines are always just like the man in the room: they understand nothing and do not speak Chinese.", "They are merely manipulating symbols without knowing what they mean.", "Searle writes: \"I can have any formal program you like, but I still understand nothing.", "\"===Speed and complexity: appeals to intuition===The following arguments (and the intuitive interpretations of the arguments above) do not directly explain how a Chinese speaking mind could exist in Searle's room, or how the symbols he manipulates could become meaningful.", "However, by raising doubts about Searle's intuitions they support other positions, such as the system and robot replies.", "These arguments, if accepted, prevent Searle from claiming that his conclusion is obvious by undermining the intuitions that his certainty requires.Several critics believe that Searle's argument relies entirely on intuitions.", "Ned Block writes \"Searle's argument depends for its force on intuitions that certain entities do not think.\"", "Daniel Dennett describes the Chinese room argument as a misleading \"intuition pump\" and writes \"Searle's thought experiment depends, illicitly, on your imagining too simple a case, an irrelevant case, and drawing the 'obvious' conclusion from it.", "\"Some of the arguments above also function as appeals to intuition, especially those that are intended to make it seem more plausible that the Chinese room contains a mind, which can include the robot, commonsense knowledge, brain simulation and connectionist replies.", "Several of the replies above also address the specific issue of complexity.", "The connectionist reply emphasizes that a working artificial intelligence system would have to be as complex and as interconnected as the human brain.", "The commonsense knowledge reply emphasizes that any program that passed a Turing test would have to be \"an extraordinarily supple, sophisticated, and multilayered system, brimming with 'world knowledge' and meta-knowledge and meta-meta-knowledge\", as Daniel Dennett explains.==== Speed and complexity replies ====:Many of these critiques emphasize speed and complexity of the human brain, which processes information at 100 billion operations per second (by some estimates).", "Several critics point out that the man in the room would probably take millions of years to respond to a simple question, and would require \"filing cabinets\" of astronomical proportions.", "This brings the clarity of Searle's intuition into doubt.", ":An especially vivid version of the speed and complexity reply is from Paul and Patricia Churchland.", "They propose this analogous thought experiment: \"Consider a dark room containing a man holding a bar magnet or charged object.", "If the man pumps the magnet up and down, then, according to Maxwell's theory of artificial luminance (AL), it will initiate a spreading circle of electromagnetic waves and will thus be luminous.", "But as all of us who have toyed with magnets or charged balls well know, their forces (or any other forces for that matter), even when set in motion produce no luminance at all.", "It is inconceivable that you might constitute real luminance just by moving forces around!\"", "Churchland's point is that the problem is that he would have to wave the magnet up and down something like 450 trillion times per second in order to see anything.", ":Stevan Harnad is critical of speed and complexity replies when they stray beyond addressing our intuitions.", "He writes \"Some have made a cult of speed and timing, holding that, when accelerated to the right speed, the computational may make a phase transition into the mental.", "It should be clear that is not a counterargument but merely an ''ad hoc'' speculation (as is the view that it is all just a matter of ratcheting up to the right degree of 'complexity.", "')\"Searle argues that his critics are also relying on intuitions, however his opponents' intuitions have no empirical basis.", "He writes that, in order to consider the \"system reply\" as remotely plausible, a person must be \"under the grip of an ideology\".", "The system reply only makes sense (to Searle) if one assumes that any \"system\" can have consciousness, just by virtue of being a system with the right behavior and functional parts.", "This assumption, he argues, is not tenable given our experience of consciousness.===Other minds and zombies: meaninglessness===Several replies argue that Searle's argument is irrelevant because his assumptions about the mind and consciousness are faulty.", "Searle believes that human beings directly experience their consciousness, intentionality and the nature of the mind every day, and that this experience of consciousness is not open to question.", "He writes that we must \"presuppose the reality and knowability of the mental.\"", "The replies below question whether Searle is justified in using his own experience of consciousness to determine that it is more than mechanical symbol processing.", "In particular, the other minds reply argues that we cannot use our experience of consciousness to answer questions about other minds (even the mind of a computer), the epiphenoma replies question whether we can make any argument at all about something like consciousness which can not, by definition, be detected by any experiment, and the eliminative materialist reply argues that Searle's own personal consciousness does not \"exist\" in the sense that Searle thinks it does.====Other minds reply==== :The \"Other Minds Reply\" points out that Searle's argument is a version of the problem of other minds, applied to machines.", "There is no way we can determine if other people's subjective experience is the same as our own.", "We can only study their behavior (i.e., by giving them our own Turing test).", "Critics of Searle argue that he is holding the Chinese room to a higher standard than we would hold an ordinary person.", ":Nils Nilsson writes \"If a program behaves ''as if'' it were multiplying, most of us would say that it is, in fact, multiplying.", "For all I know, Searle may only be behaving ''as if'' he were thinking deeply about these matters.", "But, even though I disagree with him, his simulation is pretty good, so I'm willing to credit him with real thought.", "\":Alan Turing anticipated Searle's line of argument (which he called \"The Argument from Consciousness\") in 1950 and makes the other minds reply.", "He noted that people never consider the problem of other minds when dealing with each other.", "He writes that \"instead of arguing continually over this point it is usual to have the polite convention that everyone thinks.\"", "The Turing test simply extends this \"polite convention\" to machines.", "He does not intend to solve the problem of other minds (for machines or people) and he does not think we need to.====Replies considering that Searle's \"consciousness\" is undetectable====:If we accept Searle's description of intentionality, consciousness, and the mind, we are forced to accept that consciousness is epiphenomenal: that it \"casts no shadow\" i.e.", "is undetectable in the outside world.", "Searle's \"causal properties\" cannot be detected by anyone outside the mind, otherwise the Chinese Room could not pass the Turing test—the people outside would be able to tell there was not a Chinese speaker in the room by detecting their causal properties.", "Since they cannot detect causal properties, they cannot detect the existence of the mental.", "Thus, Searle's \"causal properties\" and consciousness itself is undetectable, and anything that cannot be detected either does not exist or does not matter.", ":Mike Alder calls this the \"Newton's Flaming Laser Sword Reply\".", "He argues that the entire argument is frivolous, because it is non-verificationist: not only is the distinction between ''simulating'' a mind and ''having'' a mind ill-defined, but it is also irrelevant because no experiments were, or even can be, proposed to distinguish between the two.", ":Daniel Dennett provides this illustration: suppose that, by some mutation, a human being is born that does not have Searle's \"causal properties\" but nevertheless acts exactly like a human being.", "(This sort of animal is called a \"zombie\" in thought experiments in the philosophy of mind).", "This new animal would reproduce just as any other human and eventually there would be more of these zombies.", "Natural selection would favor the zombies, since their design is (we could suppose) a bit simpler.", "Eventually the humans would die out.", "So therefore, if Searle is right, it is most likely that human beings (as we see them today) are actually \"zombies\", who nevertheless insist they are conscious.", "It is impossible to know whether we are all zombies or not.", "Even if we are all zombies, we would still believe that we are not.====Eliminative materialist reply====:Several philosophers argue that consciousness, as Searle describes it, does not exist.", "Daniel Dennett describes consciousness as a \"user illusion\".", ":This position is sometimes referred to as eliminative materialism: the view that consciousness is not a concept that can \"enjoy reduction\" to a strictly mechanical (i.e.", "material) description, but rather is a concept that will be simply ''eliminated'' once the way the ''material'' brain works is fully understood, in just the same way as the concept of a demon has already been eliminated from science rather than enjoying reduction to a strictly mechanical description.", "Other mental properties, such as original intentionality (also called “meaning”, “content”, and “semantic character”), are also commonly regarded as special properties related to beliefs and other propositional attitudes.", "Eliminative materialism maintains that propositional attitudes such as beliefs and desires, among other intentional mental states that have content, do not exist.", "If eliminative materialism is the correct scientific account of human cognition then the assumption of the Chinese room argument that \"minds have mental contents (semantics)\" must be rejected.Searle disagrees with this analysis and argues that \"the study of the mind starts with such facts as that humans have beliefs, while thermostats, telephones, and adding machines don't ... what we wanted to know is what distinguishes the mind from thermostats and livers.\"", "He takes it as obvious that we can detect the presence of consciousness and dismisses these replies as being off the point.=== Other replies ===Margaret Boden argued in her paper \"Escaping from the Chinese Room\" that even if the person in the room does not understand the Chinese, it does not mean there is no understanding in the room.", "The person in the room at least understands the rule book used to provide output responses." ], [ "In popular culture", "The Chinese room argument is a central concept in Peter Watts's novels ''Blindsight'' and (to a lesser extent) ''Echopraxia''.", "Greg Egan illustrates the concept succinctly (and somewhat horrifically) in his 1990 short story ''Learning to Be Me,'' in his collection ''Axiomatic''.It is a central theme in the video game ''Zero Escape: Virtue's Last Reward'', and ties into the game's narrative.", "A similar human computer is imagined in Liu Cixin's novel ''The Three-Body Problem'', described thus by Philip Steiner: \"a massive human-computer by instrumentalizing millions of soldiers who take the role of signal input and signal output and are instructed to perform different logical circuits, like an AND gate and an OR gate\"." ], [ "See also", "* Computational models of language acquisition* Emergence* ''I Am a Strange Loop''* Knowledge argument* Large language model* Philosophical zombie* Stochastic parrot* Synthetic intelligence* Knowledge argument* Leibniz's gap" ], [ "Notes" ], [ "Citations" ], [ "References", "* * Also available at * * * * * :''Page numbers above refer to a standard PDF print of the article.", "''* * * * * :''Page numbers above refer to a standard PDF print of the article.", "''* :''Page numbers above refer to a standard PDF print of the article.", "''* * * :''Page numbers above refer to a standard PDF print of the article.", "''* * * * * * * * * * * ** * * * * * * * .", "Reprinted in .", "* :''Page numbers above refer to a standard PDF print of the article.", "See also Searle's original draft.", "''* * paperback: .", "* * * * * * * * * :''Page numbers above refer to a standard PDF print of the article.", "''* * :''Page numbers above and diagram contents refer to the Lyceum PDF print of the article.''" ], [ "Further reading", "* General presentations of the argument :**** The Chinese Room Argument.", "''Stanford Encyclopedia of Philosophy''** Understanding the Chinese Room, Mark Rosenfelder* Sources involving John Searle :** Chinese room argument by John Searle on Scholarpedia** The Chinese Room Argument, part 4 of the September 2, 1999 interview with Searle Philosophy and the Habits of Critical Thinking in the Conversations With History series**John R. Searle, “What Your Computer Can’t Know” (review of Luciano Floridi, ''The Fourth Revolution: How the Infosphere Is Reshaping Human Reality'', Oxford University Press, 2014; and Nick Bostrom, ''Superintelligence: Paths, Dangers, Strategies'', Oxford University Press, 2014), ''The New York Review of Books'', vol.", "LXI, no.", "15 (October 9, 2014), pp. 52–55.", "*Criticism of the argument :** A Refutation of John Searle's \"Chinese Room Argument\" , by Bob Murphy**, PDF at author's homepage , critical paper based on the assumption that the CR cannot use its inputs (which are in Chinese) to change its program (which is in English).", "**** John Preston and Mark Bishop, \"Views into the Chinese Room\", Oxford University Press, 2002.Includes chapters by John Searle, Roger Penrose, Stevan Harnad and Kevin Warwick.", "**Margaret Boden, \"Escaping from the Chinese room\", Cognitive Science Research Papers No.", "CSRP 092, University of Sussex, School of Cognitive Sciences, 1987, , online PDF, \"an excerpt from a chapter\" in the then unpublished \"Computer Models of Mind: : Computational Approaches in Theoretical Psychology\", (1988); reprinted in Boden (ed.)", "\"The Philosophy of Artificial Intelligence\" (1989) and (1990); Boden \"Artificial Intelligence in Psychology: Interdisciplinary Essays\" , MIT Press, 1989, chapter 6; reprinted in Heil, pp.", "253–266 (1988) (possibly abridged); J. Heil (ed.)", "\"Philosophy of Mind: A Guide and Anthology\", Oxford University Press, 2004, pages 253–266 (same version as in \"Artificial Intelligence in Psychology\")" ] ]
wikipedia
[ [ "Charon (disambiguation)" ], [ "Introduction", "'''Charon''', in Greek mythology, is the ferryman who carried the souls of the dead to the underworld.", "'''Charon''' may also refer to:" ], [ "Arts, entertainment, and media", "*''Caronte'' (album) (''Charon''), a 1971 album by Italian band The Trip*Charon (band), a Finnish gothic metal band*Charon (CrossGen), a comic book character from CrossGen Entertainment's Sigilverse*Charon (''Dungeons & Dragons''), a lord of the Yugoloths whose primary function is to provide passage across the River Styx for a steep price*Charon (Marvel Comics), a villainous wizard*Charon (The Three Worlds), a fictional human species from Ian Irvine's arc of novels, ''The Three Worlds Cycle''*Charon, an ''Eve Online'' freighter*Charon, a summon from a password-enhanced ''Golden Sun: The Lost Age'' and ''Golden Sun: Dark Dawn''* ''Charon V'', a fictional submarine in Michael Crichton's novel ''Sphere''*Commander Charon, one of the Galactic Commanders from ''Pokémon Platinum''" ], [ "People with the name", "*Charon, a Theban military commander (''fl.''", "mid-4th century BC); see Androcydes*Charon of Naucratis, a historian *Charon of Carthage, a historian*Charon of Lampsacus, a historian *Alexios Charon, early 11th-century Byzantine official*Charon Asetoyer (born 1951), Comanche activist and women's health advocate*Carl Charon (born 1940), former American football player*Jacques Charon (1920–1975), French actor and film director*Jean-Émile Charon (1920–1998), French nuclear physicist, philosopher and writer.", "*Joel M. Charon (1939–2018), professor emeritus of sociology at Minnesota State University at Moorhead *Rita Charon (born 1949), physician and literary scholar *Viala Charon (1794–1880), French soldier, Governor General of Algeria, Senator of France" ], [ "Places", "*Charon (moon), a moon of the dwarf planet Pluto*Charon, Louisiana, United States, an unincorporated community in Vermilion Parish" ], [ "Science and technology", "*Charon (gun), an open source 3D-printable gun*''Charon'' (arachnid), a genus of whipspider*Charon (software), a legacy hardware emulator for VAX, Alpha, HP 3000, PDP-11, and SPARC systems*Charon (web browser), a web browser for the Inferno operating system*''Blue Origin Charon'', the first flight test vehicle of Blue Origin" ], [ "Other uses", "*Charon (horse), a racehorse*HMS ''Charon'', several ships of the British Royal Navy" ], [ "See also", "*Caron (disambiguation)*Eugenie Margeurite Honoree Charen (1786–1855), French painter*Mona Charen (born 1957), American columnist, political analyst and writer*Charron (disambiguation)*Charun (disambiguation)*Chaeron (disambiguation)" ] ]
wikipedia
[ [ "Circle" ], [ "Introduction", "A '''circle''' is a shape consisting of all points in a plane that are at a given distance from a given point, the centre.", "The distance between any point of the circle and the centre is called the radius.", "The circle has been known since before the beginning of recorded history.", "Natural circles are common, such as the full moon or a slice of round fruit.", "The circle is the basis for the wheel, which, with related inventions such as gears, makes much of modern machinery possible.", "In mathematics, the study of the circle has helped inspire the development of geometry, astronomy and calculus." ], [ "Terminology", "* Annulus: a ring-shaped object, the region bounded by two concentric circles.", "* Arc: any connected part of a circle.", "Specifying two end points of an arc and a centre allows for two arcs that together make up a full circle.", "* Centre: the point equidistant from all points on the circle.", "* Chord: a line segment whose endpoints lie on the circle, thus dividing a circle into two segments.", "* Circumference: the length of one circuit along the circle, or the distance around the circle.", "* Diameter: a line segment whose endpoints lie on the circle and that passes through the centre; or the length of such a line segment.", "This is the largest distance between any two points on the circle.", "It is a special case of a chord, namely the longest chord for a given circle, and its length is twice the length of a radius.", "* Disc: the region of the plane bounded by a circle.", "In strict mathematical usage, a circle is only the boundary of the disc, while in everyday the terms \"circle\" and \"disc\" may be used interchangeably.", "* Lens: the region common to (the intersection of) two overlapping discs.", "* Radius: a line segment joining the centre of a circle with any single point on the circle itself; or the length of such a segment, which is half (the length of) a diameter.", "Usually, the radius is denoted and required to be a positive number.", "A circle with is a degenerate case consisting of a single point.", "* Sector: a region bounded by two radii of equal length with a common centre and either of the two possible arcs, determined by this centre and the endpoints of the radii.", "* Segment: a region bounded by a chord and one of the arcs connecting the chord's endpoints.", "The length of the chord imposes a lower boundary on the diameter of possible arcs.", "Sometimes the term ''segment'' is used only for regions not containing the centre of the circle to which their arc belongs to.", "* Secant: an extended chord, a coplanar straight line, intersecting a circle in two points.", "* Semicircle: one of the two possible arcs determined by the endpoints of a diameter, taking its midpoint as centre.", "In non-technical common usage it may mean the interior of the two-dimensional region bounded by a diameter and one of its arcs, that is technically called a half-disc.", "A half-disc is a special case of a segment, namely the largest one.", "* Tangent: a coplanar straight line that has one single point in common with a circle (\"touches the circle at this point\").All of the specified regions may be considered as ''open'', that is, not containing their boundaries, or as ''closed'', including their respective boundaries.Chord, secant, tangent, radius, and diameterArc, sector, and segment" ], [ "Etymology", "The word ''circle'' derives from the Greek κίρκος/κύκλος (''kirkos/kuklos''), itself a metathesis of the Homeric Greek κρίκος (''krikos''), meaning \"hoop\" or \"ring\".", "The origins of the words ''circus'' and ''circuit'' are closely related." ], [ "History", "Circular cave paintings in Santa Barbara County, CaliforniaCircles in an old Arabic astronomical drawing.Prehistoric people made stone circles and timber circles, and circular elements are common in petroglyphs and cave paintings.", "Disc-shaped prehistoric artifacts include the Nebra sky disc and jade discs called Bi.The Egyptian Rhind papyrus, dated to 1700 BCE, gives a method to find the area of a circle.", "The result corresponds to (3.16049...) as an approximate value of .Book 3 of Euclid's ''Elements'' deals with the properties of circles.", "Euclid's definition of a circle is:In Plato's Seventh Letter there is a detailed definition and explanation of the circle.", "Plato explains the perfect circle, and how it is different from any drawing, words, definition or explanation.", "Early science, particularly geometry and astrology and astronomy, was connected to the divine for most medieval scholars, and many believed that there was something intrinsically \"divine\" or \"perfect\" that could be found in circles.In 1880 CE, Ferdinand von Lindemann proved that is transcendental, proving that the millennia-old problem of squaring the circle cannot be performed with straightedge and compass.With the advent of abstract art in the early 20th century, geometric objects became an artistic subject in their own right.", "Wassily Kandinsky in particular often used circles as an element of his compositions.===Symbolism and religious use===compass in this 13th-century manuscript is a symbol of God's act of Creation.", "Notice also the circular shape of the halo.From the time of the earliest known civilisations – such as the Assyrians and ancient Egyptians, those in the Indus Valley and along the Yellow River in China, and the Western civilisations of ancient Greece and Rome during classical Antiquity – the circle has been used directly or indirectly in visual art to convey the artist's message and to express certain ideas.However, differences in worldview (beliefs and culture) had a great impact on artists' perceptions.", "While some emphasised the circle's perimeter to demonstrate their democratic manifestation, others focused on its centre to symbolise the concept of cosmic unity.", "In mystical doctrines, the circle mainly symbolises the infinite and cyclical nature of existence, but in religious traditions it represents heavenly bodies and divine spirits.The circle signifies many sacred and spiritual concepts, including unity, infinity, wholeness, the universe, divinity, balance, stability and perfection, among others.", "Such concepts have been conveyed in cultures worldwide through the use of symbols, for example, a compass, a halo, the vesica piscis and its derivatives (fish, eye, aureole, mandorla, etc.", "), the ouroboros, the Dharma wheel, a rainbow, mandalas, rose windows and so forth.", "Magic circles are part of some traditions of Western esotericism." ], [ "Analytic results", "===Circumference===The ratio of a circle's circumference to its diameter is (pi), an irrational constant approximately equal to 3.141592654.Thus the circumference ''C'' is related to the radius ''r'' and diameter ''d'' by:===Area enclosed===Area enclosed by a circle = × area of the shaded squareAs proved by Archimedes, in his Measurement of a Circle, the area enclosed by a circle is equal to that of a triangle whose base has the length of the circle's circumference and whose height equals the circle's radius, which comes to multiplied by the radius squared:Equivalently, denoting diameter by ''d'',that is, approximately 79% of the circumscribing square (whose side is of length ''d'').The circle is the plane curve enclosing the maximum area for a given arc length.", "This relates the circle to a problem in the calculus of variations, namely the isoperimetric inequality.===Equations======= Cartesian coordinates ====Circle of radius ''r'' = 1, centre (''a'', ''b'') = (1.2, −0.5)===== Equation of a circle =====In an ''x''–''y'' Cartesian coordinate system, the circle with centre coordinates (''a'', ''b'') and radius ''r'' is the set of all points (''x'', ''y'') such thatThis equation, known as the ''equation of the circle'', follows from the Pythagorean theorem applied to any point on the circle: as shown in the adjacent diagram, the radius is the hypotenuse of a right-angled triangle whose other sides are of length |''x'' − ''a''| and |''y'' − ''b''|.", "If the circle is centred at the origin (0, 0), then the equation simplifies to===== Parametric form =====The equation can be written in parametric form using the trigonometric functions sine and cosine aswhere ''t'' is a parametric variable in the range 0 to 2, interpreted geometrically as the angle that the ray from (''a'', ''b'') to (''x'', ''y'') makes with the positive ''x'' axis.An alternative parametrisation of the circle isIn this parameterisation, the ratio of ''t'' to ''r'' can be interpreted geometrically as the stereographic projection of the line passing through the centre parallel to the ''x'' axis (see Tangent half-angle substitution).", "However, this parameterisation works only if ''t'' is made to range not only through all reals but also to a point at infinity; otherwise, the leftmost point of the circle would be omitted.===== 3-point form =====The equation of the circle determined by three points not on a line is obtained by a conversion of the ''3-point form of a circle equation'':===== Homogeneous form =====In homogeneous coordinates, each conic section with the equation of a circle has the formIt can be proven that a conic section is a circle exactly when it contains (when extended to the complex projective plane) the points ''I''(1: ''i'': 0) and ''J''(1: −''i'': 0).", "These points are called the circular points at infinity.====Polar coordinates====In polar coordinates, the equation of a circle iswhere ''a'' is the radius of the circle, are the polar coordinates of a generic point on the circle, and are the polar coordinates of the centre of the circle (i.e., ''r''0 is the distance from the origin to the centre of the circle, and ''φ'' is the anticlockwise angle from the positive ''x'' axis to the line connecting the origin to the centre of the circle).", "For a circle centred on the origin, i.e.", ", this reduces to .", "When , or when the origin lies on the circle, the equation becomesIn the general case, the equation can be solved for ''r'', givingWithout the ± sign, the equation would in some cases describe only half a circle.====Complex plane====In the complex plane, a circle with a centre at ''c'' and radius ''r'' has the equationIn parametric form, this can be written asThe slightly generalised equationfor real ''p'', ''q'' and complex ''g'' is sometimes called a generalised circle.", "This becomes the above equation for a circle with , since .", "Not all generalised circles are actually circles: a generalised circle is either a (true) circle or a line.===Tangent lines===The tangent line through a point ''P'' on the circle is perpendicular to the diameter passing through ''P''.", "If and the circle has centre (''a'', ''b'') and radius ''r'', then the tangent line is perpendicular to the line from (''a'', ''b'') to (''x''1, ''y''1), so it has the form .", "Evaluating at (''x''1, ''y''1) determines the value of ''c'', and the result is that the equation of the tangent isorIf , then the slope of this line isThis can also be found using implicit differentiation.When the centre of the circle is at the origin, then the equation of the tangent line becomesand its slope is" ], [ "Properties", "* The circle is the shape with the largest area for a given length of perimeter (see Isoperimetric inequality).", "* The circle is a highly symmetric shape: every line through the centre forms a line of reflection symmetry, and it has rotational symmetry around the centre for every angle.", "Its symmetry group is the orthogonal group O(2,''R'').", "The group of rotations alone is the circle group '''T'''.", "* All circles are similar.", "** A circle circumference and radius are proportional.", "** The area enclosed and the square of its radius are proportional.", "** The constants of proportionality are 2 and respectively.", "* The circle that is centred at the origin with radius 1 is called the unit circle.", "** Thought of as a great circle of the unit sphere, it becomes the Riemannian circle.", "* Through any three points, not all on the same line, there lies a unique circle.", "In Cartesian coordinates, it is possible to give explicit formulae for the coordinates of the centre of the circle and the radius in terms of the coordinates of the three given points.", "See circumcircle.===Chord===* Chords are equidistant from the centre of a circle if and only if they are equal in length.", "* The perpendicular bisector of a chord passes through the centre of a circle; equivalent statements stemming from the uniqueness of the perpendicular bisector are:** A perpendicular line from the centre of a circle bisects the chord.", "** The line segment through the centre bisecting a chord is perpendicular to the chord.", "* If a central angle and an inscribed angle of a circle are subtended by the same chord and on the same side of the chord, then the central angle is twice the inscribed angle.", "* If two angles are inscribed on the same chord and on the same side of the chord, then they are equal.", "* If two angles are inscribed on the same chord and on opposite sides of the chord, then they are supplementary.", "** For a cyclic quadrilateral, the exterior angle is equal to the interior opposite angle.", "* An inscribed angle subtended by a diameter is a right angle (see Thales' theorem).", "* The diameter is the longest chord of the circle.", "** Among all the circles with a chord AB in common, the circle with minimal radius is the one with diameter AB.", "* If the intersection of any two chords divides one chord into lengths ''a'' and ''b'' and divides the other chord into lengths ''c'' and ''d'', then .", "* If the intersection of any two perpendicular chords divides one chord into lengths ''a'' and ''b'' and divides the other chord into lengths ''c'' and ''d'', then equals the square of the diameter.", "* The sum of the squared lengths of any two chords intersecting at right angles at a given point is the same as that of any other two perpendicular chords intersecting at the same point and is given by 8''r''2 − 4''p''2, where ''r'' is the circle radius, and ''p'' is the distance from the centre point to the point of intersection.", "* The distance from a point on the circle to a given chord times the diameter of the circle equals the product of the distances from the point to the ends of the chord.===Tangent===* A line drawn perpendicular to a radius through the end point of the radius lying on the circle is a tangent to the circle.", "* A line drawn perpendicular to a tangent through the point of contact with a circle passes through the centre of the circle.", "* Two tangents can always be drawn to a circle from any point outside the circle, and these tangents are equal in length.", "* If a tangent at ''A'' and a tangent at ''B'' intersect at the exterior point ''P'', then denoting the centre as ''O'', the angles ∠''BOA'' and ∠''BPA'' are supplementary.", "* If ''AD'' is tangent to the circle at ''A'' and if ''AQ'' is a chord of the circle, then .===Theorems===Secant–secant theorem* The chord theorem states that if two chords, ''CD'' and ''EB'', intersect at ''A'', then .", "* If two secants, ''AE'' and ''AD'', also cut the circle at ''B'' and ''C'' respectively, then (corollary of the chord theorem).", "* A tangent can be considered a limiting case of a secant whose ends are coincident.", "If a tangent from an external point ''A'' meets the circle at ''F'' and a secant from the external point ''A'' meets the circle at ''C'' and ''D'' respectively, then (tangent–secant theorem).", "* The angle between a chord and the tangent at one of its endpoints is equal to one half the angle subtended at the centre of the circle, on the opposite side of the chord (tangent chord angle).", "* If the angle subtended by the chord at the centre is 90°, then , where ''ℓ'' is the length of the chord, and ''r'' is the radius of the circle.", "* If two secants are inscribed in the circle as shown at right, then the measurement of angle ''A'' is equal to one half the difference of the measurements of the enclosed arcs ( and ).", "That is, , where ''O'' is the centre of the circle (secant–secant theorem).===Inscribed angles===Inscribed-angle theoremAn inscribed angle (examples are the blue and green angles in the figure) is exactly half the corresponding central angle (red).", "Hence, all inscribed angles that subtend the same arc (pink) are equal.", "Angles inscribed on the arc (brown) are supplementary.", "In particular, every inscribed angle that subtends a diameter is a right angle (since the central angle is 180°).===Sagitta===The sagitta is the vertical segment.The sagitta (also known as the versine) is a line segment drawn perpendicular to a chord, between the midpoint of that chord and the arc of the circle.Given the length ''y'' of a chord and the length ''x'' of the sagitta, the Pythagorean theorem can be used to calculate the radius of the unique circle that will fit around the two lines:Another proof of this result, which relies only on two chord properties given above, is as follows.", "Given a chord of length ''y'' and with sagitta of length ''x'', since the sagitta intersects the midpoint of the chord, we know that it is a part of a diameter of the circle.", "Since the diameter is twice the radius, the \"missing\" part of the diameter is () in length.", "Using the fact that one part of one chord times the other part is equal to the same product taken along a chord intersecting the first chord, we find that (.", "Solving for ''r'', we find the required result." ], [ "Compass and straightedge constructions", "There are many compass-and-straightedge constructions resulting in circles.The simplest and most basic is the construction given the centre of the circle and a point on the circle.", "Place the fixed leg of the compass on the centre point, the movable leg on the point on the circle and rotate the compass.===Construction with given diameter===* Construct the midpoint of the diameter.", "* Construct the circle with centre passing through one of the endpoints of the diameter (it will also pass through the other endpoint).Construct a circle through points A, B and C by finding the perpendicular bisectors (red) of the sides of the triangle (blue).", "Only two of the three bisectors are needed to find the centre.===Construction through three noncollinear points===* Name the points , and ,* Construct the perpendicular bisector of the segment .", "* Construct the perpendicular bisector of the segment .", "* Label the point of intersection of these two perpendicular bisectors .", "(They meet because the points are not collinear).", "* Construct the circle with centre passing through one of the points , or (it will also pass through the other two points)." ], [ "Circle of Apollonius", "Apollonius' definition of a circle: constantApollonius of Perga showed that a circle may also be defined as the set of points in a plane having a constant ''ratio'' (other than 1) of distances to two fixed foci, ''A'' and ''B''.", "(The set of points where the distances are equal is the perpendicular bisector of segment ''AB'', a line.)", "That circle is sometimes said to be drawn ''about'' two points.The proof is in two parts.", "First, one must prove that, given two foci ''A'' and ''B'' and a ratio of distances, any point ''P'' satisfying the ratio of distances must fall on a particular circle.", "Let ''C'' be another point, also satisfying the ratio and lying on segment ''AB''.", "By the angle bisector theorem the line segment ''PC'' will bisect the interior angle ''APB'', since the segments are similar:Analogously, a line segment ''PD'' through some point ''D'' on ''AB'' extended bisects the corresponding exterior angle ''BPQ'' where ''Q'' is on ''AP'' extended.", "Since the interior and exterior angles sum to 180 degrees, the angle ''CPD'' is exactly 90 degrees; that is, a right angle.", "The set of points ''P'' such that angle ''CPD'' is a right angle forms a circle, of which ''CD'' is a diameter.Second, see for a proof that every point on the indicated circle satisfies the given ratio.===Cross-ratios===A closely related property of circles involves the geometry of the cross-ratio of points in the complex plane.", "If ''A'', ''B'', and ''C'' are as above, then the circle of Apollonius for these three points is the collection of points ''P'' for which the absolute value of the cross-ratio is equal to one:Stated another way, ''P'' is a point on the circle of Apollonius if and only if the cross-ratio is on the unit circle in the complex plane.=== Generalised circles===If ''C'' is the midpoint of the segment ''AB'', then the collection of points ''P'' satisfying the Apollonius conditionis not a circle, but rather a line.Thus, if ''A'', ''B'', and ''C'' are given distinct points in the plane, then the locus of points ''P'' satisfying the above equation is called a \"generalised circle.\"", "It may either be a true circle or a line.", "In this sense a line is a generalised circle of infinite radius." ], [ "Inscription in or circumscription about other figures", "In every triangle a unique circle, called the incircle, can be inscribed such that it is tangent to each of the three sides of the triangle.About every triangle a unique circle, called the circumcircle, can be circumscribed such that it goes through each of the triangle's three vertices.A tangential polygon, such as a tangential quadrilateral, is any convex polygon within which a circle can be inscribed that is tangent to each side of the polygon.", "Every regular polygon and every triangle is a tangential polygon.A cyclic polygon is any convex polygon about which a circle can be circumscribed, passing through each vertex.", "A well-studied example is the cyclic quadrilateral.", "Every regular polygon and every triangle is a cyclic polygon.", "A polygon that is both cyclic and tangential is called a bicentric polygon.A hypocycloid is a curve that is inscribed in a given circle by tracing a fixed point on a smaller circle that rolls within and tangent to the given circle." ], [ "Limiting case of other figures", "The circle can be viewed as a limiting case of various other figures:* The series of regular polygons with ''n'' sides has the circle as its limit as ''n'' approaches infinity.", "This fact was applied by Archimedes to approximate π.", "* A Cartesian oval is a set of points such that a weighted sum of the distances from any of its points to two fixed points (foci) is a constant.", "An ellipse is the case in which the weights are equal.", "A circle is an ellipse with an eccentricity of zero, meaning that the two foci coincide with each other as the centre of the circle.", "A circle is also a different special case of a Cartesian oval in which one of the weights is zero.", "* A superellipse has an equation of the form for positive ''a'', ''b'', and ''n''.", "A supercircle has .", "A circle is the special case of a supercircle in which .", "* A Cassini oval is a set of points such that the product of the distances from any of its points to two fixed points is a constant.", "When the two fixed points coincide, a circle results.", "* A curve of constant width is a figure whose width, defined as the perpendicular distance between two distinct parallel lines each intersecting its boundary in a single point, is the same regardless of the direction of those two parallel lines.", "The circle is the simplest example of this type of figure." ], [ "Locus of constant sum", "Consider a finite set of points in the plane.", "The locus of points such that the sum of the squares of the distances to the given points is constant is a circle, whose centre is at the centroid of the given points.A generalization for higher powers of distances is obtained if under points the vertices of the regular polygon are taken.", "The locus of points such that the sum of the -th power of distances to the vertices of a given regular polygon with circumradius is constant is a circle, ifwhose centre is the centroid of the .In the case of the equilateral triangle, the loci of the constant sums of the second and fourth powers are circles, whereas for the square, the loci are circles for the constant sums of the second, fourth, and sixth powers.", "For the regular pentagon the constant sum of the eighth powers of the distances will be added and so forth." ], [ "Squaring the circle", "Squaring the circle is the problem, proposed by ancient geometers, of constructing a square with the same area as a given circle by using only a finite number of steps with compass and straightedge.In 1882, the task was proven to be impossible, as a consequence of the Lindemann–Weierstrass theorem, which proves that pi () is a transcendental number, rather than an algebraic irrational number; that is, it is not the root of any polynomial with rational coefficients.", "Despite the impossibility, this topic continues to be of interest for pseudomath enthusiasts." ], [ "Generalizations", "===In other ''p''-norms===Illustrations of unit circles (see also superellipse) in different -norms (every vector from the origin to the unit circle has a length of one, the length being calculated with length-formula of the corresponding ).Defining a circle as the set of points with a fixed distance from a point, different shapes can be considered circles under different definitions of distance.", "In ''p''-norm, distance is determined byIn Euclidean geometry, ''p'' = 2, giving the familiarIn taxicab geometry, ''p'' = 1.Taxicab circles are squares with sides oriented at a 45° angle to the coordinate axes.", "While each side would have length using a Euclidean metric, where ''r'' is the circle's radius, its length in taxicab geometry is 2''r''.", "Thus, a circle's circumference is 8''r''.", "Thus, the value of a geometric analog to is 4 in this geometry.", "The formula for the unit circle in taxicab geometry is in Cartesian coordinates andin polar coordinates.A circle of radius 1 (using this distance) is the von Neumann neighborhood of its centre.A circle of radius ''r'' for the Chebyshev distance (''L''∞ metric) on a plane is also a square with side length 2''r'' parallel to the coordinate axes, so planar Chebyshev distance can be viewed as equivalent by rotation and scaling to planar taxicab distance.", "However, this equivalence between ''L''1 and ''L''∞ metrics does not generalize to higher dimensions.===Topological definition===The circle is the one-dimensional hypersphere (the 1-sphere).In topology, a circle is not limited to the geometric concept, but to all of its homeomorphisms.", "Two topological circles are equivalent if one can be transformed into the other via a deformation of '''R'''3 upon itself (known as an ambient isotopy)." ], [ "Specially named circles", "* Apollonian circles* Archimedean circle* Archimedes' twin circles* Bankoff circle* Carlyle circle* Chromatic circle* Circle of antisimilitude* Ford circle* Geodesic circle* Johnson circles* Schoch circles* Woo circles===Of a triangle===* Apollonius circle of the excircles* Brocard circle* Excircle* Incircle* Lemoine circle* Lester circle* Malfatti circles* Mandart circle* Nine-point circle* Orthocentroidal circle* Parry circle* Polar circle (geometry)* Spieker circle* Van Lamoen circle===Of certain quadrilaterals===* Eight-point circle of an orthodiagonal quadrilateral===Of a conic section===* Director circle* Directrix circle===Of a torus===* Villarceau circles" ], [ "See also", "* Affine sphere* Apeirogon* Circle fitting* Gauss circle problem* Inversion in a circle* Line–circle intersection* List of circle topics* Sphere* Three points determine a circle* Translation of axes" ], [ "References" ], [ "Further reading", "* * \"Circle\" in The MacTutor History of Mathematics archive" ], [ "External links", "* * * * * *" ] ]
wikipedia
[ [ "Cardinal (Catholic Church)" ], [ "Introduction", "The coat of arms of a cardinal (who is a bishop or archbishop) is indicated by a red galero (wide-brimmed hat) with 15 tassels on each side (the motto and escutcheon are proper to the individual cardinal).A '''cardinal''' (; ) is a senior member of the clergy of the Catholic Church.", "Cardinals are created by the pope and typically hold the title for life.", "Collectively, they constitute the College of Cardinals.The most solemn responsibility of the cardinals is to elect a new pope in a conclave, almost always from among themselves (with a few historical exceptions), when the Holy See is vacant.", "During the period between a pope's death or resignation and the election of his successor, the day-to-day governance of the Holy See is in the hands of the College of Cardinals.", "The right to participate in a conclave is limited to cardinals who have not reached the age of 80 years by the day the vacancy occurs.", "In addition, cardinals collectively participate in papal consistories (which generally take place annually), in which matters of importance to the Church are considered and new cardinals may be created.", "Cardinals of working age are also appointed to roles overseeing dicasteries of the Roman Curia, the central administration of the Catholic Church.Cardinals are drawn from a variety of backgrounds, being appointed as cardinals ''in addition'' to their existing roles within the Church.", "Most cardinals are bishops and archbishops leading dioceses and archdioceses around the world – often the most prominent diocese or archdiocese in their country.", "Others are titular bishops who are current or former officials within the Roman Curia (generally the heads of dicasteries and other bodies linked to the Curia).", "A very small number are priests recognised by the pope for their service to the Church; as canon law requires them to be generally consecrated as bishops before they are made cardinals, but some are granted a papal dispensation.", "There are no strict criteria for elevation to the College of Cardinals.", "Since 1917, a potential cardinal must already be at least a priest, but laymen have been cardinals in the past.", "The selection is entirely up to the pope and tradition is his only guide.", "there are serving cardinals, of whom are eligible to vote in a conclave to elect a new pope." ], [ "History", "Cardinal Richelieu, chief minister of FranceThere is general disagreement about the origin of the term, but a chief consensus that \"''cardinalis''\" is etymologically from the Latin word (meaning \"pivot\" or \"hinge\") was first used in late antiquity to designate a bishop or priest who was incorporated into a church for which he had not originally been ordained.", "In Rome the first persons to be called cardinals were the deacons of the seven regions of the city at the beginning of the 6th century, when the word began to mean \"principal\", \"eminent\", or \"superior\".", "The name was also given to the senior priest in each of the \"title\" churches (the parish churches) of Rome and to the bishops of the seven sees surrounding the city.", "By the 8th century the Roman cardinals constituted a privileged class among the Roman clergy.", "They took part in the administration of the church of Rome and in the papal liturgy.", "By decree of a synod of 769, only a cardinal was eligible to become Bishop of Rome.", "Cardinals were granted the privilege of wearing the red hat by Pope Innocent IV in 1244.In cities other than Rome, the name cardinal began to be applied to certain church men as a mark of honour.", "The earliest example of this occurs in a letter sent by Pope Zacharias in 747 to Pippin the Younger, ruler of the Franks, in which Zacharias applied the title to the priests of Paris to distinguish them from country clergy.", "This meaning of the word spread rapidly, and from the 9th century various episcopal cities had a special class among the clergy known as cardinals.", "The use of the title was reserved for the cardinals of Rome in 1567 by Pius V.In 1059 (five years after the East-West Schism), the right of electing the pope was reserved to the principal clergy of Rome and the bishops of the seven suburbicarian sees.", "In the 12th century the practice of appointing ecclesiastics from outside Rome as cardinals began, with each of them assigned a church in Rome as his titular church or linked with one of the suburbicarian dioceses, while still being incardinated in a diocese other than that of Rome.The term ''cardinal'' at one time applied to any priest permanently assigned or incardinated to a church, or specifically to the senior priest of an important church, based on the Latin ''cardo'' (hinge), meaning \"pivotal\" as in \"principal\" or \"chief\".", "The term was applied in this sense as early as the 9th century to the priests of the ''tituli'' (parishes) of the diocese of Rome.In the year 1563, the Ecumenical Council of Trent, headed by Pope Pius IV, wrote about the importance of selecting good cardinals: \"nothing is more necessary to the Church of God than that the holy Roman pontiff apply that solicitude which by the duty of his office he owes the universal Church in a very special way by associating with himself as cardinals the most select persons only, and appoint to each church most eminently upright and competent shepherds; and this the more so, because our Lord Jesus Christ will require at his hands the blood of the sheep of Christ that perish through the evil government of shepherds who are negligent and forgetful of their office.", "\"The earlier influence of temporal rulers, notably the kings of France, reasserted itself through the influence of cardinals of certain nationalities or politically significant movements.", "Traditions even developed entitling certain monarchs, including those of Austria, Spain, and France, to nominate one of their trusted clerical subjects to be created cardinal, a so-called \"crown-cardinal\".In early modern times, cardinals often had important roles in secular affairs.", "In some cases, they took on powerful positions in government.", "In Henry VIII's England, his chief minister was for some time Cardinal Wolsey.", "Cardinal Richelieu's power was so great that he was for many years effectively the ruler of France.", "Richelieu's successor was also a cardinal, Jules Mazarin.", "Guillaume Dubois and André-Hercule de Fleury complete the list of the four great cardinals to have ruled France.", "In Portugal, due to a succession crisis, one cardinal, Henry of Portugal, was crowned king, the only example of a cardinal-king.While the incumbents of some sees are regularly made cardinals, and some countries are entitled to at least one cardinal by concordat (usually earning either its primate or the metropolitan of the capital city the cardinal's hat), almost no see carries an actual right to the cardinalate, not even if its bishop is a patriarch: the notable exception is the Patriarch of Lisbon who, by Pope Clement XII's 1737 bull ''Inter praecipuas apostolici ministerii'', is accorded the right to be elevated to the rank of cardinal in the consistory following his appointment." ], [ "Papal elections", "In 1059, Pope Nicholas II gave cardinals the right to elect the Bishop of Rome in the papal bull .", "For a time this power was assigned exclusively to the cardinal bishops, but in 1179 the Third Lateran Council restored the right to the whole body of cardinals." ], [ "Numbers", "In 1586, Pope Sixtus V limited the number of cardinals to 70: six cardinal bishops, 50 cardinal priests, and 14 cardinal deacons.", "Pope John XXIII exceeded that limit citing the need to staff Church offices.", "In November 1970 in ''Ingravescentem aetatem'', Pope Paul VI established that electors would be under the age of eighty years.", "When it took effect on 1 January 1971, it deprived 25 cardinals of the right to participate in a conclave.", "In October 1975 in ''Romano Pontifici eligendo'', he set the maximum number of electors at 120, while establishing no limit on the overall size of the college.Popes can set aside church laws and they have regularly brought the number of cardinals under the age of 80 to more than 120, twice reaching as high as 135 with Pope John Paul II's consistories of February 2001 and October 2003.No more than 120 electors have ever participated in a conclave, but most canon lawyers believe that if their number exceeded 120 they would all participate.Pope Paul VI also increased the number of cardinal bishops by assigning that rank, in 1965, to patriarchs of the Eastern Catholic Churches when named cardinals.", "In 2018, Pope Francis expanded the cardinal bishops of Roman title, because this had not been done despite recent decades' expansion in the two lower orders of cardinals, besides having all six such cardinals being over the age limit for a conclave." ], [ "Titular churches", "Cardinal Innitzer, Archbishop of Vienna and Cardinal-Priest of San CrisogonoEach cardinal is assigned a titular church upon his creation, which is always a church in the city of Rome.", "Through the process of opting (''optazione''), a cardinal can raise through the ranks from cardinal deacon to priest, and from cardinal priest to that of cardinal bishop - in which case he obtains one of the suburbicarian sees located around the city of Rome.", "The only exception is for patriarchs of the Eastern Catholic Churches.", "Nevertheless, cardinals possess no power of governance nor are they to intervene in any way in matters which pertain to the administration of goods, discipline, or the service of their titular churches.", "They are allowed to celebrate Mass and hear confessions and lead visits and pilgrimages to their titular churches, in coordination with the staff of the church.", "They often support their churches monetarily, and many cardinals do keep in contact with the pastoral staffs of their titular churches.", "The term cardinal is from the Latin word \"cardo\" meaning a hinge.", "Here it means a \"door\", an example of synecdoche, a figure of speech whereby the part refers to the whole.", "The \"door\" is the address of the titular church from which the cardinal derives his membership of the Roman clergy, who elect the pope.The Dean of the College of Cardinals in addition to such a titular church also receives the titular bishopric of Ostia, the primary suburbicarian see.", "Cardinals governing a particular church retain that church." ], [ "Title and reference style", "In 1630, Pope Urban VIII decreed their title to be ''Eminence'' (previously, it had been \"illustrissimo\" and \"reverendissimo\") and decreed that their secular rank would equate to Prince, making them second only to the pope and crowned monarchs.In accordance with tradition, they sign by placing the title \"Cardinal\" (abbreviated ''Card.'')", "after their personal name and before their surname as, for instance, \"John Card(inal) Doe\" or, in Latin, \"Ioannes Card(inalis) Doe\".", "Some writers, such as James-Charles Noonan, hold that, in the case of cardinals, the form used for signatures should be used also when referring to them in English.", "However, official sources, such as the Catholic News Service, say that the correct form for referring to a cardinal in English is normally as \"Cardinal First name Surname\".", "This is the rule given also in stylebooks not associated with the church.", "This style is also generally followed on the websites of the Holy See and episcopal conferences.", "Oriental patriarchs who are created cardinals customarily use \"Sanctae Ecclesiae Cardinalis\" as their full title, probably because they do not belong to the Roman clergy.The First name Cardinal Surname order is used in the Latin proclamation of the election of a new pope by the cardinal protodeacon, if the new pope is a cardinal, as has been the case since 1378.The term '''Prince of the Church''' has historically been applied to cardinals of the Catholic church, and sometimes more broadly to senior members of the church hierarchy.", "It has been rejected by Pope Francis, who stated to a group of newly created cardinals \"He (Jesus) does not call you to become 'princes' of the Church, to 'sit on his right or on his left.'", "He calls you to serve like Him and with Him.\"", "The term is still applied, both seriously and as a criticism of the perceived attitudes of some cardinals." ], [ "Orders and their chief offices", "Choir dress of a cardinal=== Cardinal bishops ===Angelo Sodano was Dean of the College of Cardinals from 2005 to 2019.Cardinal bishops (cardinals of the episcopal order; ) are the senior order of cardinals.", "Though in modern times the vast majority of cardinals are also bishops or archbishops, few are \"cardinal bishops\".", "For most of the second millennium there were six cardinal bishops, each presiding over one of the seven suburbicarian sees around Rome: Ostia, Albano, Porto and Santa Rufina, Palestrina, Sabina and Mentana, Frascati, and Velletri.", "Velletri was united with Ostia from 1150 until 1914, when Pope Pius X separated them again, but decreed that whichever cardinal bishop became Dean of the College of Cardinals would keep the suburbicarian see he already held, adding to it that of Ostia, with the result that there continued to be only six cardinal bishops.", "Since 1962, the cardinal bishops have only a titular relationship with the suburbicarian sees, each of which is governed by a separate ordinary.Until 1961, membership in the order of cardinal bishops was achieved through precedence in the College of Cardinals.", "When a suburbicarian see fell vacant, the most senior cardinal by precedence could exercise his option to claim the see and be promoted to the order of cardinal bishops.", "Pope John XXIII abolished that privilege on 10 March 1961 and made the right to promote someone to the order of cardinal bishops the sole prerogative of the pope.In 1965, Pope Paul VI decreed in his ''motu proprio'' ''Ad purpuratorum Patrum Collegium'' that patriarchs of the Eastern Catholic Churches who were named cardinals (i.e.", "\"cardinal patriarchs\") would also be cardinal bishops, ranking after the six Roman rite cardinal bishops of the suburbicarian sees.", "(Latin Church patriarchs who become cardinals are cardinal priests, not cardinal bishops: for example Angelo Scola was made Patriarch of Venice in 2002 and cardinal priest of Santi XII Apostoli in 2003.)", "Those of cardinal patriarch rank continue to hold their patriarchal see and are not assigned any Roman title (suburbicarian see or title or deaconry).At the June 2018 consistory, Pope Francis increased the number of Latin Church cardinal bishops to match the expansion in cardinal priests and cardinal deacons in recent decades.", "He elevated four cardinals to this rank granting their titular churches and deaconries suburbicarian rank ''pro hac vice'' (temporarily) and making them equivalent to suburbicarian see titles.", "At the time of the announcement, all six cardinal bishops of suburbicarian see titles, as well as two of the three cardinal patriarchs, were non-electors as they had reached the age of 80.Pope Francis created another cardinal bishop in the same way on 1 May 2020, bringing the number of Latin Church cardinal bishops to eleven.The Dean of the College of Cardinals, the highest ranking cardinal, was formerly the longest serving cardinal bishop, but since 1965 is elected by the Latin Church cardinal bishops from among their number, subject to papal approval.", "Likewise the Vice-Dean, formerly the second longest serving, is also elected.", "Seniority of the remaining Latin Church cardinal bishops is still by date of appointment to the rank.=== Cardinal priests ===Cardinal priests () are the most numerous of the three orders of cardinals in the Catholic Church, ranking above the cardinal deacons and below the cardinal bishops.", "Those who are named cardinal priests today are generally also bishops of important dioceses throughout the world, though some hold Curial positions.In modern times, the term \"cardinal priest\" is interpreted as meaning a cardinal who is of the order of priests.", "Originally, however, this referred to certain key priests of important churches of the Diocese of Rome, who were recognized as the ''cardinal'' priests, the important priests chosen by the pope to advise him in his duties as Bishop of Rome (the Latin ''cardo'' means \"hinge\").", "Certain clerics in many dioceses at the time, not just that of Rome, were said to be the key personnel—the term gradually became exclusive to Rome to indicate those entrusted with electing the Bishop of Rome, the pope.Cardinal-priest Thomas WolseyWhile the cardinalate has long been expanded beyond the Roman pastoral clergy and Roman Curia, every cardinal priest has a titular church in Rome, though they may be bishops or archbishops elsewhere, just as cardinal bishops were given one of the suburbicarian dioceses around Rome.", "Pope Paul VI abolished all administrative rights cardinals had with regard to their titular churches, though the cardinal's name and coat of arms are still posted in the church, and they are expected to celebrate Mass and preach there if convenient when they are in Rome.While the number of cardinals was small from the times of the Roman Empire to the Renaissance, and frequently smaller than the number of recognized churches entitled to a cardinal priest, in the 16th century the college expanded markedly.", "In 1587, Pope Sixtus V sought to arrest this growth by fixing the maximum size of the college at 70, including 50 cardinal priests, about twice the historical number.", "This limit was respected until 1958, and the list of titular churches modified only on rare occasions, generally when a building fell into disrepair.", "When Pope John XXIII abolished the limit, he began to add new churches to the list, which Popes Paul VI and John Paul II continued to do.", "Today there are close to 150 titular churches, out of over 300 churches in Rome.The cardinal who is the longest-serving member of the order of cardinal priests is titled ''cardinal protopriest''.", "He had certain ceremonial duties in the conclave that have effectively ceased because he would generally have already reached age 80, at which cardinals are barred from the conclave.", "The current cardinal protopriest is Michael Michai Kitbunchu of Thailand.=== Cardinal deacons ===The cardinal deacons () are the lowest-ranking cardinals.", "Cardinals elevated to the diaconal order are either officials of the Roman Curia or priests elevated after their 80th birthday.", "Bishops with diocesan responsibilities, however, are created cardinal priests.Cardinal deacons derive originally from the seven deacons in the Papal Household who supervised the Church's works in the seven districts of Rome during the early Middle Ages, when church administration was effectively the government of Rome and provided all social services.", "They came to be called \"cardinal deacons\" by the late eighth century, and they were granted active rights in papal elections and made eligible for the election as pope by the decree of 769.Cardinals elevated to the diaconal order are mainly officials of the Roman Curia holding various posts in the church administration.", "Their number and influence has varied through the years.", "While historically predominantly Italian the group has become much more internationally diverse in later years.", "While in 1939 about half were Italian, by 1994 the number was reduced to one third.", "Their influence in the election of the pope has been considered important.", "They are better informed and connected than the dislocated cardinals but their level of unity has been varied.", "Under the 1587 decree of Pope Sixtus V, which fixed the maximum size of the College of Cardinals, there were 14 cardinal deacons.", "Later the number increased.", "As late as 1939 almost half of the cardinals were members of the Curia.", "Pius XII reduced this percentage to 24 percent.", "John XXIII brought it back up to 37 percent but Paul VI brought it down to 27 percent.", "John Paul II maintained this ratio.As of 2005, there were over 50 churches recognized as cardinalatial deaconries, though there were only 30 cardinals of the order of deacons.", "Cardinal deacons have long enjoyed the right to \"opt for the order of cardinal priests\" (''optazione'') after they have been cardinal deacons for 10 years.", "They may on such elevation take a vacant \"title\" (a church allotted to a cardinal priest as the church in Rome with which he is associated) or their diaconal church may be temporarily elevated to a cardinal priest's \"title\" for that occasion.", "When elevated to cardinal priests, they take their precedence according to the day they were first made cardinal deacons (thus ranking above cardinal priests who were elevated to the college after them, regardless of order).When not celebrating Mass but still serving a liturgical function, such as the semiannual ''Urbi et Orbi'' papal blessing, some Papal Masses and some events at Ecumenical Councils, cardinal deacons can be recognized by the dalmatics they would don with the simple white mitre (so called ''mitra simplex'').==== Cardinal protodeacon ====The cardinal protodeacon is the senior cardinal deacon in order of appointment to the College of Cardinals.", "If he is a cardinal elector and participates in a conclave, he announces a new pope's election and name from the central balcony of St. Peter's Basilica in Vatican City.", "The protodeacon also bestows the pallium on the new pope and crowns him with the papal tiara, although the crowning has not been celebrated since Pope John Paul I opted for a simpler papal inauguration ceremony in 1978.The current cardinal protodeacon is Renato Raffaele Martino.==== Cardinal protodeacons since 1887 ====Cardinal Martino, current Cardinal Protodeacon* Giuseppe Pecci, S.J.", "(20 December 1887 – 8 February 1890)* John Henry Newman, C.O.", "(8 February 1890 – 11 August 1890)* Joseph Hergenröther (11 August 1890 – 3 October 1890)* Tommaso Maria Zigliara, O.P.", "(3 October 1890 – 1 June 1891)* Isidoro Verga (1 June 1891 – 22 June 1896)* Luigi Macchi (22 June 1896 – 29 March 1907); announced election of Pope Pius X (1903)* Andreas Steinhuber, S.J.", "(29 March 1907 – 15 October 1907)* Francesco Segna (15 October 1907 – 4 January 1911)* Francesco Salesio Della Volpe (4 January 1911 – 5 November 1916†); announced election of Pope Benedict XV (1914)* Gaetano Bisleti (5 November 1916 – 17 December 1928*); announced election of Pope Pius XI (1922)* Camillo Laurenti (17 December 1928 – 16 December 1935*)* Camillo Caccia-Dominioni (16 December 1935 – 12 November 1946†); announced election of Pope Pius XII (1939)* Nicola Canali (12 November 1946 – 3 August 1961†); announced election of Pope John XXIII (1958)* Alfredo Ottaviani (3 August 1961 – 26 June 1967*); announced election of Pope Paul VI (1963)* Arcadio Larraona Saralegui, CMF (26 June 1967 – 28 April 1969*)* William Theodore Heard (28 April 1969 – 18 May 1970*)* Antonio Bacci (18 May 1970 – 20 January 1971†)* Michael Browne, OP (20 January 1971 – 31 March 1971†)* Federico Callori di Vignale (31 March 1971 – 8 August 1971†)* Charles Journet (8 August 1971 – 5 March 1973*)* Pericle Felici (5 March 1973 – 30 June 1979*); announced elections of Pope John Paul I (1978) and Pope John Paul II (1978)* Sergio Pignedoli (30 June 1979 – 15 June 1980†)* Umberto Mozzoni (15 June 1980 – 2 February 1983*)* Opilio Rossi (2 February 1983 – 22 June 1987*)* Giuseppe Caprio (22 June 1987 – 26 November 1990*)* Aurelio Sabattani (26 November 1990 – 5 April 1993*)* Duraisamy Simon Lourdusamy (5 April 1993 – 29 January 1996*)* Eduardo Martínez Somalo (29 January 1996 – 9 January 1999*)* Pio Laghi (9 January 1999 – 26 February 2002*)* Luigi Poggi (26 February 2002 – 24 February 2005*)* Jorge Medina (24 February 2005 – 23 February 2007*); announced election of Pope Benedict XVI (2005)* Darío Castrillón Hoyos (23 February 2007 – 1 March 2008*)* Agostino Cacciavillan (1 March 2008 – 21 February 2011*)* Jean-Louis Tauran (21 February 2011 – 12 June 2014*); announced election of Pope Francis (2013)* Renato Raffaele Martino (12 June 2014 –)Ceased to be protodeacon upon being raised to the order of cardinal-priest† Was protodeacon at time of death" ], [ "Special types of cardinals", "===Camerlengo===The Cardinal Camerlengo of the Holy Roman Church, assisted by the Vice-Camerlengo and the other prelates of the office known as the Apostolic Camera, has functions that in essence are limited to a period of ''sede vacante'' of the papacy.", "He is to collate information about the financial situation of all administrations dependent on the Holy See and present the results to the College of Cardinals, as they gather for the papal conclave.===Cardinals who are not bishops===Reginald Pole was a cardinal for 18 years before he was ordained a priest.Until 1918, any cleric, even one only in minor orders, could be created a cardinal (see \"lay cardinals\", below), but enrolled only in the order of cardinal deacons.", "For example, in the 16th century, Reginald Pole was a cardinal for 18 years before he was ordained a priest.", "The 1917 Code of Canon Law mandated that all cardinals, even cardinal deacons, had to be priests, and, in 1962, Pope John XXIII set the norm that all cardinals be consecrated as bishops, even if they are only priests at the time of appointment.", "As a consequence of these two changes, canon 351 of the 1983 Code of Canon Law requires that a cardinal be at least in the order of priesthood at his appointment, and that those who are not already bishops must receive episcopal consecration.", "Several cardinals near to or over the age of 80 when appointed have obtained dispensation from the rule of having to be a bishop.", "These were all appointed cardinal-deacons, but Roberto Tucci and Albert Vanhoye lived long enough to exercise the right of option and be promoted to the rank of cardinal-priest.", "No cardinal who was not a bishop has participated in a papal conclave since the 1962 rule change.", "However, as of Ángel Fernández Artime, Rector Major of the Salesians, who was created a cardinal by Pope Francis on 30 September 2023, has not been consecrated a bishop and is aged , is a cardinal elector.A cardinal who is not a bishop is entitled to wear and use the episcopal vestments and other pontificalia (episcopal regalia: mitre, crozier, zucchetto, pectoral cross, and ring).", "He has both actual and honorary precedence over archbishops, and bishops who are not cardinals.", "However, he cannot perform the sacrament of ordination or other rites reserved solely to bishops.===\"Lay cardinals\"===At various times, there have been cardinals who had only received first tonsure and minor orders but not yet been ordained as deacons or priests.", "Though clerics, they were inaccurately called \"lay cardinals\".", "Teodolfo Mertel was among the last of the lay cardinals.", "When he died in 1899 he was the last surviving cardinal who was not at least ordained a priest.", "With the revision of the Code of Canon Law promulgated in 1917 by Pope Benedict XV, only those who are already priests or bishops may be appointed cardinals.", "Since the time of Pope John XXIII a priest who is appointed a cardinal must be consecrated a bishop, unless he obtains a dispensation." ], [ "Cardinals ''in pectore'' or secret cardinals", "In addition to the named cardinals, the pope may name secret cardinals or cardinals (Latin for ''in the breast'').", "During the Western Schism, many cardinals were created by the contending popes.", "Beginning with the reign of Pope Martin V, cardinals were created without publishing their names until later, a practice termed ''creati et reservati in pectore''.", "A cardinal named ''in pectore'' is known only to the pope.", "In the modern era, popes have named cardinals ''in pectore'' to protect them or their congregations from political reprisals.", "If conditions change, the pope makes the appointment public.", "The cardinal in question then ranks in precedence with those made cardinals at the time of his ''in pectore'' appointment.", "If a pope dies before revealing the identity of an ''in pectore'' cardinal, the person's status as cardinal expires.", "The last pope known to have named a cardinal ''in pectore'' is Pope John Paul II, who named four, including one whose identity was never revealed." ], [ "Vesture and privileges", "File:Cardinal Théodore Adrien Sarr 2.JPG|alt=Théodore Adrien Cardinal Sarr with a ferraiolo, and wearing a red cassock, but not the rest of the choir dress.|Cardinal Sarr with a ferraiolo and wearing a red cassock, but not the rest of the choir dress.File:Kardinaal III Danneels en Kasper.JPG|alt=Cardinals Walter Kasper (left) and Godfried Danneels (right) wearing their choir dress: scarlet (red) cassock, white rochet trimmed with lace, scarlet mozetta, scarlet biretta (over the usual scarlet zucchetto), and pectoral cross on a cord.|Cardinals Walter Kasper (left) and Godfried Danneels (right) wearing their choir dress: scarlet (red) cassock, white rochet trimmed with lace, scarlet mozetta, scarlet biretta (over the usual scarlet zucchetto), and pectoral cross on a cord (or, in Danneels' case, wrongly on a chain).File:Missione del Guaricano-cardinale Tarcisio Bertone.jpg|alt=Tarcisio Cardinal Bertone in dress for hot tropical countries (white cassock with scarlet piping and buttons).|Cardinal Bertone in dress for hot tropical countries (white cassock with scarlet piping and buttons).", "When in choir dress, a Latin Church cardinal wears scarlet garments—the blood-like red symbolizes a cardinal's willingness to die for his faith.", "Excluding the rochet — which is always white—the scarlet garments include the cassock, mozzetta, and biretta (over the usual scarlet zucchetto).", "The biretta of a cardinal is distinctive not merely for its scarlet color, but also for the fact that it does not have a pompon or tassel on the top as do the birettas of other prelates.", "Until the 1460s, it was customary for cardinals to wear a violet or blue cape unless granted the privilege of wearing red when acting on papal business.", "His normal-wear cassock is black but has scarlet piping and a scarlet fascia (sash).", "Occasionally, a cardinal wears a scarlet ''ferraiolo'' which is a cape worn over the shoulders, tied at the neck in a bow by narrow strips of cloth in the front, without any 'trim' or piping on it.", "It is because of the scarlet color of cardinals' vesture that the bird of the same name has become known as such.A Cardinal in Profile, 1880, by Jehan Georges Vibert (Morgan Library and Museum, New York City)Eastern Catholic cardinals continue to wear the normal dress appropriate to their liturgical tradition, though some may line their cassocks with scarlet and wear scarlet fascias, or in some cases, wear Eastern-style cassocks entirely of scarlet.In previous times, at the consistory at which the pope named a new cardinal, he would bestow upon him a distinctive wide-brimmed hat called a galero.", "This custom was discontinued in 1969 and the investiture now takes place with the scarlet biretta.", "In ecclesiastical heraldry, however, the scarlet galero is still displayed on the cardinal's coat of arms.", "Cardinals had the right to display the galero in their cathedral, and when a cardinal died, it would be suspended from the ceiling above his tomb.", "Some cardinals will still have a galero made, even though it is not officially part of their apparel.To symbolize their bond with the papacy, the pope gives each newly appointed cardinal a gold ring, which is traditionally kissed by Catholics when greeting a cardinal (as with a bishop's episcopal ring).", "Before the new uniformity imposed by John Paul II, each cardinal was given a ring, the central piece of which was a gem, usually a sapphire, with the pope's stemma engraved on the inside.", "There is now no gemstone, and the pope chooses the image on the outside: under Pope Benedict XVI it was a modern depiction of the crucifixion of Jesus, with Mary and John to each side.", "The ring includes the pope's coat of arms on the inside.Cardinals have in canon law a \"privilege of forum\" (i.e., exemption from being judged by ecclesiastical tribunals of ordinary rank): only the pope is competent to judge them in matters subject to ecclesiastical jurisdiction (cases that refer to matters that are spiritual or linked with the spiritual, or with regard to infringement of ecclesiastical laws and whatever contains an element of sin, where culpability must be determined and the appropriateecclesiastical penalty imposed).", "The pope either decides the case himself or delegates the decision to a tribunal, usually one of the tribunals or congregations of the Roman Curia.", "Without such delegation, no ecclesiastical court, even the Roman Rota, is competent to judge a canon law case against a cardinal.Additionally, canon law gives cardinals the faculty of hearing confessions validly and licitly everywhere, whereas other priests and bishops must be granted this faculty and might be restricted in its use by the local bishop." ], [ "See also", "* Cardinal-Infante (disambiguation)* Cardinal-nephew* Cardinal protector* Hierarchy of the Catholic Church* List of current cardinals* List of the creations of the cardinals" ], [ "Notes" ], [ "References" ], [ "Bibliography", "* * * * * * Hollingswirth, Mary, Miles Pattenden and Arnold Witte, eds (2020), '' A Companion to the Early Modern Cardinal''.", "Leiden/Boston: Brill.", "ISBN 978-90-04-41544-7" ], [ "External links", "* Salvador Miranda.", "The Cardinals of the Holy Roman Church.", "A digital resource consisting of the biographical entries of the cardinals from 494 to 2014 and of the events and documents concerning the origin of the Roman cardinalate and its historical evolution* Next Cardinal Creating Consistory by Pope Benedict XVI – The Required Background Data (including statistical data and links).", "Popes and the Papacy website (Anura Guruge).", "Retrieved 2010-09-08.", "* GCatholic on all Cardinals** List of All Cardinals By Precedence by GCatholic** List of all Cardinal Titular Churches by GCatholic** List of all Cardinal Deaconries by GCatholic* Catholic-pages List of Cardinals* Thomas J. Reese, ''Inside the Vatican: The Politics and Organization of the Catholic Church'', Harvard University Press, 1996 * Cardinal Rating a website listing the day to day statements printed in the news by current cardinals" ] ]
wikipedia
[ [ "Cantigas de Santa Maria" ], [ "Introduction", "An illustration from the E codex of the ''Cantigas de Santa Maria''.The '''''Cantigas de Santa Maria''''' (, ; \"Canticles of Holy Mary\") are 420 poems with musical notation, written in the medieval Galician-Portuguese language during the reign of Alfonso X of Castile ''El Sabio'' (1221–1284).", "Traditionally, they are all attributed to Alfonso, though scholars have since established that the musicians and poets of his court were responsible for most of them, with Alfonso being credited with a few as well.It is one of the largest collections of monophonic (solo) songs from the Middle Ages and is characterized by the mention of the Virgin Mary in every song, while every tenth song is a hymn.The ''Cantigas'' have survived in four manuscript codices: two at El Escorial, one at Madrid's National Library, and one in Florence, Italy.", "The E codex from El Escorial is illuminated with colored miniatures showing pairs of musicians playing a wide variety of instruments.", "The ''Códice Rico'' (T) from El Escorial and the one in the Biblioteca Nazionale Centrale of Florence (F) are richly illuminated with narrative vignettes." ], [ "Description", "The Cantigas are written in the early Medieval Galician variety of Galician-Portuguese, using Galician spelling; this was because of Galician-Portuguese being fashionable as a lyrical language in Castile at the time, as well as Alfonso X having passed part of his early years in Galicia and so probably being a fluent speaker since his childhood.The Cantigas are a collection of 420 poems, 356 of which are in a narrative format relating to Marian miracles; the rest of them, except an introduction and two prologues, are of songs of praise or involve Marian festivities.", "The Cantigas depict the Virgin Mary in a very humanized way, often having her play a role in earthly episodes.The authors are unknown, although several studies have suggested that Galician poet Airas Nunes might have been the author of a large number of the Cantiga poems.", "King Alfonso X — named as Affonso in the Cantigas — is also believed to be an author of some of them as he refers himself in first person.", "Support for this theory can be found in the prologue of the Cantigas.", "Also, many sources credit Alfonso owing to his influence on other works within the poetic tradition, including his introduction on religious song.", "Although King Alfonso X's authorship is debatable, his influence is not.", "While the other major works that came out of Alfonso's workshops, including histories and other prose texts, were in Castilian, the Cantigas are in Galician-Portuguese, and reflect the popularity in the Castilian court of other poetic corpuses such as the ''cantigas d'amigo'' and ''cantigas d'amor''.A lute player.The metrics are extraordinarily diverse: 280 different formats for the 420 Cantigas.", "The most common are the ''virelai'' and the ''rondeau''.", "The length of the lines varies between two and 24 syllables.", "The narrative voice in many of the songs describes an erotic relationship, in the troubadour fashion, with the Divine.The music is written in notation which is similar to that used for chant, but also contains some information about the length of the notes.", "Several transcriptions exist.", "The Cantigas are frequently recorded and performed by early music groups, and quite a few CDs featuring music from the Cantigas are available.===Codices===Miniatures, Cantiga #35The Cantigas are preserved in four manuscripts: * ''To'' (''códice de Toledo,'' Biblioteca Nacional de España, MS 10069, link to manuscript)* ''T'' (''códice rico,'' Biblioteca de El Escorial, MS T.I.1, link to manuscript)* ''F'' (''códice de Florencia,'' Florence, Biblioteca Nazionale, MS b.r.", "20, link to manuscript) * ''E'' (''códice de los músicos,'' Biblioteca de El Escorial MS B.I.2, link to manuscript)''E'' contains the largest number of songs (406 Cantigas, plus the Introduction and the Prologue); it contains 41 carefully detailed miniatures and many illuminated letters.", "''To'' is the earliest collection and contains 129 songs.", "Although not illustrated, it is richly decorated with pen flourished initials, and great care has been taken over its construction.", "The ''T'' and ''F'' manuscripts are sister volumes.", "''T'' contains 195 surviving cantigas (8 are missing due to loss of folios) which roughly correspond in order to the first two hundred in ''E'', each song being illustrated with either 6 or 12 miniatures that depict scenes from the cantiga.", "''F'' follows the same format but has only 111 cantigas, of which 7 have no text, only miniatures.", "These are basically a subset of those found in the second half of ''E'', but are presented here in a radically different order.", "''F'' was never finished, and so no music was ever added.", "Only the empty staves display the intention to add musical notation to the codex at a later date.", "It is generally thought that the codices were constructed during Alfonso's lifetime, ''To'' perhaps in the 1270s, and ''T''/''F'' and ''E'' in the early 1280s up until the time of his death in 1284.===The music===The musical forms within the Cantigas, and there are many, are still being studied.", "There have been many false leads, and there is little beyond pitch value that is very reliable.", "Mensuration is a particular problem in the Cantigas, and most attempts at determining meaningful rhythmic schemes have tended, with some exceptions, to be unsatisfactory.", "This remains a lively topic of debate and study.", "Progress, while on-going, has nevertheless been significant over the course of the last 20 years." ], [ "See also", "*Literature of Alfonso X*''Cantiga de amigo''*Llibre Vermell de Montserrat*Pergaminho Sharrer*Martin Codax*The Legend of Ero of Armenteira" ], [ "References" ], [ "Bibliography", "* ''The Songs of Holy Mary by Alfonso X, the Wise: A Translation of the Cantigas de Santa Maria.''", "Translated by Kathleen Kulp-Hill.", "Arizona Center for Medieval and Renaissance Studies, Tempe 2000.", "* ''Studies on the \"Cantigas de Santa Maria\": Art, Music, and Poetry: Proceedings of the International Symposium on the \"Cantigas de Santa Maria\" of Alfonso X, el Sabio (1221–1284) in Commemoration of Its 700th Anniversary Year–1981''.", "Co-Editors Israel J. Katz & John E. Keller; Associate Editors Samuel G. Armistead & Joseph T. Snow.", "Hispanic Seminary of Medieval Studies, Madison, 1987.", "* ''Cobras e Son: Papers on the Text Music and Manuscripts of the \"Cantigas de Santa Maria\".''", "Edited by Stephen Parkinson.", "European Humanities Research Centre, University of Oxford, Modern Humanities Research Association, 2000.", "* (Gal) Pena, Xosé Ramón, \"Historia da litratura medieval galego-portuguesa\", Santiago de Compostela, 2002, 199-210.", "* *" ], [ "External links", "* ''Cantigas de Santa María'', Códice rico, Real Biblioteca del Monasterio de San Lorenzo de El Escorial, Ms. T-I-1, link to manuscript* http://www.pbm.com/~lindahl/cantigas/ (facsimiles, illuminations, links to transcriptions)* Cantigas de Santa Maria for Singers (full text with syllable marks, pronunciation guide and concordance)* '' Cantigas de Santa Maria (Texto crítico completo)'' (full text, ed.", "José-Martinho Montero Santalha)* http://www.medieval.org/emfaq/composers/cantigas.html (a comprehensive database of the released Cantigas recordings)* http://csm.mml.ox.ac.uk/ (the Centre for the Study of the Cantigas de Santa Maria of Oxford University)* https://web.archive.org/web/20041013090228/http://perso.club-internet.fr/brassy/PartMed/Cantigas/CSMIDI.html (French site: MIDI files based on Anglés transcriptions; also texts but with many OCR errors and thousands of missing letters.", ")* Portuguese wikisource (the same inaccurate texts as the French site above).", "* *" ] ]
wikipedia
[ [ "Claudio Monteverdi" ], [ "Introduction", "Monteverdi by Bernardo Strozzi ()alt=Monteverdi's signature'''Claudio Giovanni Antonio Monteverdi''' (baptized 15 May 1567 – 29 November 1643) was an Italian composer, choirmaster and string player.", "A composer of both secular and sacred music, and a pioneer in the development of opera, he is considered a crucial transitional figure between the Renaissance and Baroque periods of music history.Born in Cremona, where he undertook his first musical studies and compositions, Monteverdi developed his career first at the court of Mantua () and then until his death in the Republic of Venice where he was ''maestro di cappella'' at the basilica of San Marco.", "His surviving letters give insight into the life of a professional musician in Italy of the period, including problems of income, patronage and politics.Much of Monteverdi's output, including many stage works, has been lost.", "His surviving music includes nine books of madrigals, large-scale religious works, such as his ''Vespro della Beata Vergine'' (''Vespers for the Blessed Virgin'') of 1610, and three complete operas.", "His opera ''L'Orfeo'' (1607) is the earliest of the genre still widely performed; towards the end of his life he wrote works for Venice, including ''Il ritorno d'Ulisse in patria'' and ''L'incoronazione di Poppea''.While he worked extensively in the tradition of earlier Renaissance polyphony, as evidenced in his madrigals, he undertook great developments in form and melody, and began to employ the basso continuo technique, distinctive of the Baroque.", "No stranger to controversy, he defended his sometimes novel techniques as elements of a ''seconda pratica'', contrasting with the more orthodox earlier style which he termed the ''prima pratica''.", "Largely forgotten during the eighteenth and much of the nineteenth centuries, his works enjoyed a rediscovery around the beginning of the twentieth century.", "He is now established both as a significant influence in European musical history and as a composer whose works are regularly performed and recorded." ], [ "Life", "===Cremona: 1567–1591===Monteverdi was baptised in the church of SS Nazaro e Celso, Cremona, on 15 May 1567.The register records his name as \"Claudio Zuan Antonio\" the son of \"Messer Baldasar Mondeverdo\".", "He was the first child of the apothecary Baldassare Monteverdi and his first wife Maddalena (née Zignani); they had married early the previous year.", "Claudio's brother Giulio Cesare Monteverdi (b.", "1573) was also to become a musician; there were two other brothers and two sisters from Baldassare's marriage to Maddalena and his subsequent marriage in 1576 or 1577.Cremona was close to the border of the Republic of Venice, and not far from the lands controlled by the Duchy of Mantua, in both of which states Monteverdi was later to establish his career.Cremona Cathedral, where Monteverdi's teacher Ingegneri was ''maestro di capella''There is no clear record of Monteverdi's early musical training, or evidence that (as is sometimes claimed) he was a member of the Cathedral choir or studied at Cremona University.", "Monteverdi's first published work, a set of motets, '' (Sacred Songs)'' for three voices, was issued in Venice in 1582, when he was only fifteen years old.", "In this, and his other initial publications, he describes himself as the pupil of Marc'Antonio Ingegneri, who was from 1581 (and possibly from 1576) to 1592 the ''maestro di cappella'' at Cremona Cathedral.", "The musicologist Tim Carter deduces that Ingegneri \"gave him a solid grounding in counterpoint and composition\", and that Monteverdi would also have studied playing instruments of the viol family and singing.Monteverdi's first publications also give evidence of his connections beyond Cremona, even in his early years.", "His second published work, ''Madrigali spirituali'' (Spiritual Madrigals, 1583), was printed at Brescia.", "His next works (his first published secular compositions) were sets of five-part madrigals, according to his biographer Paolo Fabbri: \"the inevitable proving ground for any composer of the second half of the sixteenth century ... the secular genre ''par excellence''\".", "The first book of madrigals (Venice, 1587) was dedicated to Count Marco Verità of Verona; the second book of madrigals (Venice, 1590) was dedicated to the President of the Senate of Milan, Giacomo Ricardi, for whom he had played the viola da braccio in 1587.===Mantua: 1591–1613=======Court musician====Duke Vincenzo I Gonzaga in his coronation robes (1587, by )In the dedication of his second book of madrigals, Monteverdi had described himself as a player of the ''vivuola'' (which could mean either viola da gamba or viola da braccio).", "In 1590 or 1591 he entered the service of Duke Vincenzo I Gonzaga of Mantua; he recalled in his dedication to the Duke of his third book of madrigals (Venice, 1592) that \"the most noble exercise of the ''vivuola'' opened to me the fortunate way into your service.\"", "In the same dedication he compares his instrumental playing to \"flowers\" and his compositions as \"fruit\" which as it matures \"can more worthily and more perfectly serve you\", indicating his intentions to establish himself as a composer.Duke Vincenzo was keen to establish his court as a musical centre, and sought to recruit leading musicians.", "When Monteverdi arrived in Mantua, the ''maestro di capella'' at the court was the Flemish musician Giaches de Wert.", "Other notable musicians at the court during this period included the composer and violinist Salomone Rossi, Rossi's sister, the singer Madama Europa, and Francesco Rasi.", "Monteverdi married the court singer Claudia de Cattaneis in 1599; they were to have three children, two sons (Francesco, b.", "1601 and Massimiliano, b.", "1604), and a daughter who died soon after birth in 1603.Monteverdi's brother Giulio Cesare joined the court musicians in 1602.When Wert died in 1596, his post was given to Benedetto Pallavicino, but Monteverdi was clearly highly regarded by Vincenzo and accompanied him on his military campaigns in Hungary (1595) and also on a visit to Flanders in 1599.Here at the town of Spa he is reported by his brother Giulio Cesare as encountering, and bringing back to Italy, the ''canto alla francese''.", "(The meaning of this, literally \"song in the French style\", is debatable, but may refer to the French-influenced poetry of Gabriello Chiabrera, some of which was set by Monteverdi in his ''Scherzi musicali'', and which departs from the traditional Italian style of lines of 9 or 11 syllables).", "Monteverdi may possibly have been a member of Vincenzo's entourage at Florence in 1600 for the marriage of Maria de' Medici and Henry IV of France, at which celebrations Jacopo Peri's opera ''Euridice'' (the earliest surviving opera) was premiered.", "On the death of Pallavicino in 1601, Monteverdi was confirmed as the new ''maestro di capella''.====Artusi controversy and ''seconda pratica''====The only certain portrait of Claudio Monteverdi, from the title page of ''Fiori poetici'', a 1644 book of commemorative poems for his funeralAt the turn of the 17th century, Monteverdi found himself the target of musical controversy.", "The influential Bolognese theorist Giovanni Maria Artusi attacked Monteverdi's music (without naming the composer) in his work ''L'Artusi, overo Delle imperfettioni della moderna musica (Artusi, or On the imperfections of modern music)'' of 1600, followed by a sequel in 1603.Artusi cited extracts from Monteverdi's works not yet published (they later formed parts of his fourth and fifth books of madrigals of 1603 and 1605), condemning their use of harmony and their innovations in use of musical modes, compared to orthodox polyphonic practice of the sixteenth century.", "Artusi attempted to correspond with Monteverdi on these issues; the composer refused to respond, but found a champion in a pseudonymous supporter, \"L'Ottuso Academico\" (\"The Obtuse Academic\").", "Eventually Monteverdi replied in the preface to the fifth book of madrigals that his duties at court prevented him from a detailed reply; but in a note to \"the studious reader\", he claimed that he would shortly publish a response, ''Seconda Pratica, overo Perfettione della Moderna Musica (The Second Style, or Perfection of Modern Music)''.", "This work never appeared, but a later publication by Claudio's brother Giulio Cesare made it clear that the ''seconda pratica'' which Monteverdi defended was not seen by him as a radical change or his own invention, but was an evolution from previous styles (''prima pratica'') which was complementary to them.This debate seems in any case to have raised the composer's profile, leading to reprints of his earlier books of madrigals.", "Some of his madrigals were published in Copenhagen in 1605 and 1606, and the poet Tommaso Stigliani (1573–1651) published a eulogy of him in his 1605 poem \"O sirene de' fiumi\".", "The composer of madrigal comedies and theorist Adriano Banchieri wrote in 1609: \"I must not neglect to mention the most noble of composers, Monteverdi ... his expressive qualities are truly deserving of the highest commendation, and we find in them countless examples of matchless declamation ... enhanced by comparable harmonies.\"", "The modern music historian Massimo Ossi has placed the Artusi issue in the context of Monteverdi's artistic development: \"If the controversy seems to define Monteverdi's historical position, it also seems to have been about stylistic developments that by 1600 Monteverdi had already outgrown\".The non-appearance of Monteverdi's promised explanatory treatise may have been a deliberate ploy, since by 1608, by Monteverdi's reckoning, Artusi had become fully reconciled to modern trends in music, and the ''seconda pratica'' was by then well established; Monteverdi had no need to revisit the issue.", "On the other hand, letters to Giovanni Battista Doni of 1632 show that Monteverdi was still preparing a defence of the ''seconda practica'', in a treatise entitled ''Melodia''; he may still have been working on this at the time of his death ten years later.====Opera, conflict and departure====Duke Francesco IV Gonzaga, by the studio of Frans Pourbus the YoungerIn 1606 Vincenzo's heir Francesco commissioned from Monteverdi the opera ''L'Orfeo'', to a libretto by Alessandro Striggio, for the Carnival season of 1607.It was given two performances in February and March 1607; the singers included, in the title role, Rasi, who had sung in the first performance of ''Euridice'' witnessed by Vincenzo in 1600.This was followed in 1608 by the opera ''L'Arianna'' (libretto by Ottavio Rinuccini), intended for the celebration of the marriage of Francesco to Margherita of Savoy.", "All the music for this opera is lost apart from ''Ariadne's Lament'', which became extremely popular.", "To this period also belongs the ballet entertainment ''Il ballo delle ingrate''.The strain of the hard work Monteverdi had been putting into these and other compositions was exacerbated by personal tragedies.", "His wife died in September 1607 and the young singer Caterina Martinelli, intended for the title role of ''Arianna'', died of smallpox in March 1608.Monteverdi also resented his increasingly poor financial treatment by the Gonzagas.", "He retired to Cremona in 1608 to convalesce, and wrote a bitter letter to Vincenzo's minister Annibale Chieppio in November of that year seeking (unsuccessfully) \"an honourable dismissal\".", "Although the Duke increased Monteverdi's salary and pension, and Monteverdi returned to continue his work at the court, he began to seek patronage elsewhere.", "After publishing his Vespers in 1610, which were dedicated to Pope Paul V, he visited Rome, ostensibly hoping to place his son Francesco at a seminary, but apparently also seeking alternative employment.", "In the same year he may also have visited Venice, where a large collection of his church music was being printed, with a similar intention.Duke Vincenzo died on 18 February 1612.When Francesco succeeded him, court intrigues and cost-cutting led to the dismissal of Monteverdi and his brother Giulio Cesare, who both returned, almost penniless, to Cremona.", "Despite Francesco's own death from smallpox in December 1612, Monteverdi was unable to return to favour with his successor, his brother Cardinal Ferdinando Gonzaga.", "In 1613, following the death of Giulio Cesare Martinengo, Monteverdi auditioned for his post as ''maestro'' at the basilica of San Marco in Venice, for which he submitted music for a Mass.", "He was appointed in August 1613, and given 50 ducats for his expenses (of which he was robbed, together with his other belongings, by highwaymen at Sanguinetto on his return to Cremona).===Venice: 1613–1643=======Maturity: 1613–1630====San Marco, VeniceMartinengo had been ill for some time before his death and had left the music of San Marco in a fragile state.", "The choir had been neglected and the administration overlooked.", "When Monteverdi arrived to take up his post, his principal responsibility was to recruit, train, discipline and manage the musicians of San Marco (the ''capella''), who amounted to about 30 singers and six instrumentalists; the numbers could be increased for major events.", "Among the recruits to the choir was Francesco Cavalli, who joined in 1616 at the age of 14; he was to remain connected with San Marco throughout his life, and was to develop a close association with Monteverdi.", "Monteverdi also sought to expand the repertory, including not only the traditional ''a cappella'' repertoire of Roman and Flemish composers, but also examples of the modern style which he favoured, including the use of continuo and other instruments.", "Apart from this he was of course expected to compose music for all the major feasts of the church.", "This included a new mass each year for Holy Cross Day and Christmas Eve, cantatas in honour of the Venetian Doge, and numerous other works (many of which are lost).", "Monteverdi was also free to obtain income by providing music for other Venetian churches and for other patrons, and was frequently commissioned to provide music for state banquets.", "The Procurators of San Marco, to whom Monteverdi was directly responsible, showed their satisfaction with his work in 1616 by raising his annual salary from 300 ducats to 400.The relative freedom which the Republic of Venice afforded him, compared to the problems of court politics in Mantua, are reflected in Monteverdi's letters to Striggio, particularly his letter of 13 March 1620, when he rejects an invitation to return to Mantua, extolling his present position and finances in Venice, and referring to the pension which Mantua still owes him.", "Nonetheless, remaining a Mantuan citizen, he accepted commissions from the new Duke Ferdinando, who had formally renounced his position as Cardinal in 1616 to take on the duties of state.", "These included the ''balli'' ''Tirsi e Clori'' (1616) and ''Apollo'' (1620), an opera ''Andromeda'' (1620) and an ''intermedio'', ''Le nozze di Tetide'', for the marriage of Ferdinando with Caterina de' Medici (1617).", "Most of these compositions were extensively delayed in creation – partly, as shown by surviving correspondence, through the composer's unwillingness to prioritise them, and partly because of constant changes in the court's requirements.", "They are now lost, apart from ''Tirsi e Clori'', which was included in the seventh book of madrigals (published 1619) and dedicated to the Duchess Caterina, for which the composer received a pearl necklace from the Duchess.", "A subsequent major commission, the opera ''La finta pazza Licori'', to a libretto by Giulio Strozzi, was completed for Fernando's successor Vincenzo II, who succeeded to the dukedom in 1626.Because of the latter's illness (he died in 1627), it was never performed, and it is now also lost.Letter from Monteverdi to Enzo Bentivoglio in Ferrara, 18 September 1627, (British Library, MS Mus.", "1707), discussing the composer's ''intermezzo, Didone ed Enea''Monteverdi also received commissions from other Italian states and from their communities in Venice.", "These included, for the Milanese community in 1620, music for the Feast of St. Charles Borromeo, and for the Florentine community a Requiem Mass for Cosimo II de' Medici (1621).", "Monteverdi acted on behalf of Paolo Giordano II, Duke of Bracciano, to arrange publication of works by the Cremona musician Francesco Petratti.", "Among Monteverdi's private Venetian patrons was the nobleman Girolamo Mocenigo, at whose home was premiered in 1624 the dramatic entertainment ''Il combattimento di Tancredi e Clorinda'' based on an episode from Torquato Tasso's ''La Gerusalemme liberata''.", "In 1627 Monteverdi received a major commission from Odoardo Farnese, Duke of Parma, for a series of works, and gained leave from the Procurators to spend time there during 1627 and 1628.Monteverdi's musical direction received the attention of foreign visitors.", "The Dutch diplomat and musician Constantijn Huygens, attending a Vespers service at the church of SS.", "Giovanni e Lucia, wrote that he \"heard the most perfect music I had ever heard in my life.", "It was directed by the most famous Claudio Monteverdi ... who was also the composer and was accompanied by four theorbos, two cornettos, two bassoons, one ''basso de viola'' of huge size, organs and other instruments ...\".", "Monteverdi wrote a mass, and provided other musical entertainment, for the visit to Venice in 1625 of the Crown Prince Władysław of Poland, who may have sought to revive attempts made a few years previously to lure Monteverdi to Warsaw.", "He also provided chamber music for Wolfgang Wilhelm, Count Palatine of Neuburg, when the latter was paying an incognito visit to Venice in July 1625.Correspondence of Monteverdi in 1625 and 1626 with the Mantuan courtier Ercole Marigliani reveals an interest in alchemy, which apparently Monteverdi had taken up as a hobby.", "He discusses experiments to transform lead into gold, the problems of obtaining mercury, and mentions commissioning special vessels for his experiments from the glassworks at Murano.Despite his generally satisfactory situation in Venice, Monteverdi experienced personal problems from time to time.", "He was on one occasion – probably because of his wide network of contacts – the subject of an anonymous denunciation to the Venetian authorities alleging that he supported the Habsburgs.", "He was also subject to anxieties about his children.", "His son Francesco, while a student of law at Padua in 1619, was spending in Monteverdi's opinion too much time with music, and he, therefore, moved him to the University of Bologna.", "This did not have the required result, and it seems that Monteverdi resigned himself to Francesco having a musical career – he joined the choir of San Marco in 1623.His other son Massimiliano, who graduated in medicine, was arrested by the Inquisition in Mantua in 1627 for reading forbidden literature.", "Monteverdi was obliged to sell the necklace he had received from Duchess Caterina to pay for his son's (eventually successful) defence.", "Monteverdi wrote at the time to Striggio seeking his help, and fearing that Massimiliano might be subject to torture; it seems that Striggio's intervention was helpful.", "Money worries at this time also led Monteverdi to visit Cremona to secure for himself a church canonry.====Pause and priesthood: 1630–1637====A series of disturbing events troubled Monteverdi's world in the period around 1630.Mantua was invaded by Habsburg armies in 1630, who besieged the plague-stricken town, and after its fall in July looted its treasures, and dispersed the artistic community.", "The plague was carried to Mantua's ally Venice by an embassy led by Monteverdi's confidante Striggio, and over a period of 16 months led to over 45,000 deaths, leaving Venice's population in 1633 at just above 100,000, the lowest level for about 150 years.", "Among the plague victims was Monteverdi's assistant at San Marco, and a notable composer in his own right, Alessandro Grandi.", "The plague and the after-effects of war had an inevitable deleterious effect on the economy and artistic life of Venice.", "Monteverdi's younger brother Giulio Cesare also died at this time, probably from the plague.By this time Monteverdi was in his sixties, and his rate of composition seems to have slowed down.", "He had written a setting of Strozzi's ''Proserpina rapita (The Abduction of Proserpina)'', now lost except for one vocal trio, for a Mocenigo wedding in 1630, and produced a Mass for deliverance from the plague for San Marco which was performed in November 1631.His set of ''Scherzi musicali'' was published in Venice in 1632.In 1631, Monteverdi was admitted to the tonsure, and was ordained deacon, and later priest, in 1632.Although these ceremonies took place in Venice, he was nominated as a member of Diocese of Cremona; this may imply that he intended to retire there.====Late flowering: 1637–1643====Monteverdi's tomb in the church of Santa Maria Gloriosa dei FrariThe opening of the opera house of San Cassiano in 1637, the first public opera house in Europe, stimulated the city's musical life and coincided with a new burst of the composer's activity.", "The year 1638 saw the publication of Monteverdi's eighth book of madrigals and a revision of the ''Ballo delle ingrate''.", "The eighth book contains a ''ballo'', \"Volgendi il ciel\", which may have been composed for the Holy Roman Emperor, Ferdinand III, to whom the book is dedicated.", "The years 1640–1641 saw the publication of the extensive collection of church music, ''Selva morale e spirituale''.", "Among other commissions, Monteverdi wrote music in 1637 and 1638 for Strozzi's \"Accademia degli Unisoni\" in Venice, and in 1641 a ballet, ''La vittoria d'Amore'', for the court of Piacenza.Monteverdi was still not entirely free from his responsibilities for the musicians at San Marco.", "He wrote to complain about one of his singers to the Procurators, on 9 June 1637: \"I, Claudio Monteverdi ... come humbly ... to set forth to you how Domenicato Aldegati ... a bass, yesterday morning ... at the time of the greatest concourse of people ... spoke these exact words ...'The Director of Music comes from a brood of cut-throat bastards, a thieving, fucking, he-goat ... and I shit on him and whoever protects him ....Monteverdi's contribution to opera at this period is notable.", "He revised his earlier opera ''L'Arianna'' in 1640 and wrote three new works for the commercial stage, ''Il ritorno d'Ulisse in patria'' (''The Return of Ulysses to his Homeland'', 1640, first performed in Bologna with Venetian singers), ''Le nozze d'Enea e Lavinia'' (''The Marriage of Aeneas and Lavinia'', 1641, music now lost), and ''L'incoronazione di Poppea'' (''The Coronation of Poppea'', 1643).", "The introduction to the printed scenario of ''Le nozze d'Enea'', by an unknown author, acknowledges that Monteverdi is to be credited for the rebirth of theatrical music and that \"he will be sighed for in later ages, for his compositions will surely outlive the ravages of time.", "\"In his last surviving letter (20 August 1643), Monteverdi, already ill, was still hoping for the settlement of the long-disputed pension from Mantua, and asked the Doge of Venice to intervene on his behalf.", "He died in Venice on 29 November 1643, after paying a brief visit to Cremona, and is buried in the Church of the Frari.", "He was survived by his sons; Masimilliano died in 1661, Francesco after 1677." ], [ "Music", "===Background: Renaissance to Baroque===Musicians of the late Renaissance/early Baroque era (Gerard van Honthorst, ''The Concert'', 1623)There is a consensus among music historians that a period extending from the mid-15th century to around 1625, characterised in Lewis Lockwood's phrase by \"substantial unity of outlook and language\", should be identified as the period of \"Renaissance music\".", "Musical literature has also defined the succeeding period (covering music from approximately 1580 to 1750) as the era of \"Baroque music\".", "It is in the late-16th to early-17th-century overlap of these periods that much of Monteverdi's creativity flourished; he stands as a transitional figure between the Renaissance and the Baroque.In the Renaissance era, music had developed as a formal discipline, a \"pure science of relationships\" in the words of Lockwood.", "In the Baroque era it became a form of aesthetic expression, increasingly used to adorn religious, social and festive celebrations in which, in accordance with Plato's ideal, the music was subordinated to the text.", "Solo singing with instrumental accompaniment, or monody, acquired greater significance towards the end of the 16th century, replacing polyphony as the principal means of dramatic music expression.", "This was the changing world in which Monteverdi was active.", "Percy Scholes in his ''Oxford Companion to Music'' describes the \"new music\" thus: \"Composers discarded the choral polyphony of the madrigal style as barbaric, and set dialogue or soliloquy for single voices, imitating more or less the inflexions of speech and accompanying the voice by playing mere supporting chords.", "Short choruses were interspersed, but they too were homophonic rather than polyphonic.", "\"===Novice years: Madrigal books 1 and 2===Luca Marenzio, an early influence on MonteverdiIngegneri, Monteverdi's first tutor, was a master of the ''musica reservata'' vocal style, which involved the use of chromatic progressions and word-painting; Monteverdi's early compositions were grounded in this style.", "Ingegneri was a traditional Renaissance composer, \"something of an anachronism\", according to Arnold, but Monteverdi also studied the work of more \"modern\" composers such as Luca Marenzio, Luzzasco Luzzaschi, and a little later, Giaches de Wert, from whom he would learn the art of expressing passion.", "He was a precocious and productive student, as indicated by his youthful publications of 1582–83.Mark Ringer writes that \"these teenaged efforts reveal palpable ambition matched with a convincing mastery of contemporary style\", but at this stage they display their creator's competence rather than any striking originality.", "Geoffrey Chew classifies them as \"not in the most modern vein for the period\", acceptable but out-of-date.", "Chew rates the ''Canzonette'' collection of 1584 much more highly than the earlier juvenilia: \"These brief three-voice pieces draw on the airy, modern style of the villanellas of Marenzio, drawing on a substantial vocabulary of text-related madrigalisms\".The canzonetta form was much used by composers of the day as a technical exercise, and is a prominent element in Monteverdi's first book of madrigals published in 1587.In this book, the playful, pastoral settings again reflect the style of Marenzio, while Luzzaschi's influence is evident in Monteverdi's use of dissonance.", "The second book (1590) begins with a setting modelled on Marenzio of a modern verse, Torquato Tasso's \"Non si levav' ancor\", and concludes with a text from 50 years earlier: Pietro Bembo's \"Cantai un tempo\".", "Monteverdi set the latter to music in an archaic style reminiscent of the long-dead Cipriano de Rore.", "Between them is \"Ecco mormorar l'onde\", strongly influenced by de Wert and hailed by Chew as the great masterpiece of the second book.A thread common throughout these early works is Monteverdi's use of the technique of ''imitatio'', a general practice among composers of the period whereby material from earlier or contemporary composers was used as models for their own work.", "Monteverdi continued to use this procedure well beyond his apprentice years, a factor that in some critics' eyes has compromised his reputation for originality.===Madrigals 1590–1605: books 3, 4, 5===Monteverdi's first fifteen years of service in Mantua are bracketed by his publications of the third book of madrigals in 1592 and the fourth and fifth books in 1603 and 1605.Between 1592 and 1603 he made minor contributions to other anthologies.", "How much he composed in this period is a matter of conjecture; his many duties in the Mantuan court may have limited his opportunities, but several of the madrigals that he published in the fourth and fifth books were written and performed during the 1590s, some figuring prominently in the Artusi controversy.The third book shows strongly the increased influence of Wert, by that time Monteverdi's direct superior as ''maestro de capella'' at Mantua.", "Two poets dominate the collection: Tasso, whose lyrical poetry had figured prominently in the second book but is here represented through the more epic, heroic verses from ''Gerusalemme liberata'', and Giovanni Battista Guarini, whose verses had appeared sporadically in Monteverdi's earlier publications, but form around half of the contents of the third book.", "Wert's influence is reflected in Monteverdi's forthrightly modern approach, and his expressive and chromatic settings of Tasso's verses.", "Of the Guarini settings, Chew writes: \"The epigrammatic style ... closely matches a poetic and musical ideal of the period ... and often depends on strong, final cadential progressions, with or without the intensification provided by chains of suspended dissonances\".", "Chew cites the setting of \"Stracciami pur il core\" as \"a prime example of Monteverdi's irregular dissonance practice\".", "Tasso and Guarini were both regular visitors to the Mantuan court; Monteverdi's association with them and his absorption of their ideas may have helped lay the foundations of his own approach to the musical dramas that he would create a decade later.As the 1590s progressed, Monteverdi moved closer towards the form that he would identify in due course as the ''seconda pratica''.", "Claude V. Palisca quotes the madrigal ''Ohimè, se tanto amate'', published in the fourth book but written before 1600 – it is among the works attacked by Artusi – as a typical example of the composer's developing powers of invention.", "In this madrigal Monteverdi again departs from the established practice in the use of dissonance, by means of a vocal ornament Palisca describes as ''échappé''.", "Monteverdi's daring use of this device is, says Palisca, \"like a forbidden pleasure\".", "In this and in other settings the poet's images were supreme, even at the expense of musical consistency.The fourth book includes madrigals to which Artusi objected on the grounds of their \"modernism\".", "However, Ossi describes it as \"an anthology of disparate works firmly rooted in the 16th century\", closer in nature to the third book than to the fifth.", "Besides Tasso and Guarini, Monteverdi set to music verses by Rinuccini, Maurizio Moro (''Sì ch'io vorrei morire'') and Ridolfo Arlotti (''Luci serene e chiare'').", "There is evidence of the composer's familiarity with the works of Carlo Gesualdo, and with composers of the school of Ferrara such as Luzzaschi; the book was dedicated to a Ferrarese musical society, the ''Accademici Intrepidi''.The fifth book looks more to the future; for example, Monteverdi employs the ''concertato'' style with basso continuo (a device that was to become a typical feature in the emergent Baroque era), and includes a ''sinfonia'' (instrumental interlude) in the final piece.", "He presents his music through complex counterpoint and daring harmonies, although at times combining the expressive possibilities of the new music with traditional polyphony.Aquilino Coppini drew much of the music for his sacred contrafacta of 1608 from Monteverdi's 3rd, 4th and 5th books of madrigals.", "In writing to a friend in 1609 Coppini commented that Monteverdi's pieces \"require, during their performance, more flexible rests and bars that are not strictly regular, now pressing forward or abandoning themselves to slowing down ...", "In them there is a truly wondrous capacity for moving the affections\".===Opera and sacred music: 1607–1612===In Monteverdi's final five years' service in Mantua he completed the operas ''L'Orfeo'' (1607) and ''L'Arianna'' (1608), and wrote quantities of sacred music, including the ''Messa in illo tempore'' (1610) and also the collection known as ''Vespro della Beata Vergine'' which is often referred to as \"Monteverdi's ''Vespers''\" (1610).", "He also published ''Scherzi musicale a tre voci'' (1607), settings of verses composed since 1599 and dedicated to the Gonzaga heir, Francesco.", "The vocal trio in the ''Scherzi'' comprises two sopranos and a bass, accompanied by simple instrumental ritornellos.", "According to Bowers the music \"reflected the modesty of the prince's resources; it was, nevertheless, the earliest publication to associate voices and instruments in this particular way\".====''L'Orfeo''====Frontispiece of Monteverdi's opera ''L'Orfeo'', Venice edition, 1609.The opera opens with a brief trumpet toccata.", "The prologue of La musica (a figure representing music) is introduced with a ritornello by the strings, repeated often to represent the \"power of music\" – one of the earliest examples of an operatic leitmotif.", "Act 1 presents a pastoral idyll, the buoyant mood of which continues into Act 2.The confusion and grief which follow the news of Euridice's death are musically reflected by harsh dissonances and the juxtaposition of keys.", "The music remains in this vein until the act ends with the consoling sounds of the ritornello.Act 3 is dominated by Orfeo's aria \"Possente spirto e formidabil nume\" by which he attempts to persuade Caronte to allow him to enter Hades.", "Monteverdi's vocal embellishments and virtuoso accompaniment provide what Tim Carter has described as \"one of the most compelling visual and aural representations\" in early opera.", "In Act 4 the warmth of Proserpina's singing on behalf of Orfeo is retained until Orfeo fatally \"looks back\".", "The brief final act, which sees Orfeo's rescue and metamorphosis, is framed by the final appearance of the ritornello and by a lively moresca that brings the audience back to their everyday world.Throughout the opera Monteverdi makes innovative use of polyphony, extending the rules beyond the conventions which composers normally observed in fidelity to Palestrina.", "He combines elements of the traditional 16th-century madrigal with the new monodic style where the text dominates the music and sinfonias and instrumental ritornellos illustrate the action.====''L'Arianna''====The music for this opera is lost except for the ''Lamento d'Arianna'', which was published in the sixth book in 1614 as a five-voice madrigal; a separate monodic version was published in 1623.In its operatic context the lament depicts Arianna's various emotional reactions to her abandonment: sorrow, anger, fear, self-pity, desolation and a sense of futility.", "Throughout, indignation and anger are punctuated by tenderness, until a descending line brings the piece to a quiet conclusion.The musicologist Suzanne Cusick writes that Monteverdi \"created the lament as a recognizable genre of vocal chamber music and as a standard scene in opera ... that would become crucial, almost genre-defining, to the full-scale public operas of 17th-century Venice\".", "Cusick observes how Monteverdi is able to match in music the \"rhetorical and syntactical gestures\" in the text of Ottavio Rinuccini.", "The opening repeated words \"Lasciatemi morire\" (Let me die) are accompanied by a dominant seventh chord which Ringer describes as \"an unforgettable chromatic stab of pain\".", "Ringer suggests that the lament defines Monteverdi's innovative creativity in a manner similar to that in which the Prelude and the Liebestod in ''Tristan und Isolde'' announced Wagner's discovery of new expressive frontiers.Rinuccini's full libretto, which has survived, was set in modern times by Alexander Goehr (''Arianna'', 1995), including a version of Monteverdi's ''Lament''.====Vespers====Pages from the printed Magnificat of the ''Vespers'', a page from the alto partbook (left), and the corresponding page from the continuo partbook (right)The ''Vespro della Beata Vergine'', Monteverdi's first published sacred music since the ''Madrigali spirituali'' of 1583, consists of 14 components: an introductory versicle and response, five psalms interspersed with five \"sacred concertos\" (Monteverdi's term), a hymn, and two Magnificat settings.", "Collectively these pieces fulfil the requirements for a Vespers service on any feast day of the Virgin.", "Monteverdi employs many musical styles; the more traditional features, such as cantus firmus, falsobordone and Venetian canzone, are mixed with the latest madrigal style, including echo effects and chains of dissonances.", "Some of the musical features used are reminiscent of ''L'Orfeo'', written slightly earlier for similar instrumental and vocal forces.In this work the \"sacred concertos\" fulfil the role of the antiphons which divide the psalms in regular Vespers services.", "Their non-liturgical character has led writers to question whether they should be within the service, or indeed whether this was Monteverdi's intention.", "In some versions of Monteverdi's ''Vespers'' (for example, those of Denis Stevens) the concertos are replaced with antiphons associated with the Virgin, although John Whenham in his analysis of the work argues that the collection as a whole should be regarded as a single liturgical and artistic entity.All the psalms, and the Magnificat, are based on melodically limited and repetitious Gregorian chant psalm tones, around which Monteverdi builds a range of innovative textures.", "This concertato style challenges the traditional cantus firmus, and is most evident in the \"Sonata sopra Sancta Maria\", written for eight string and wind instruments plus basso continuo, and a single soprano voice.", "Monteverdi uses modern rhythms, frequent metre changes and constantly varying textures; yet, according to John Eliot Gardiner, \"for all the virtuosity of its instrumental writing and the evident care which has gone into the combinations of timbre\", Monteverdi's chief concern was resolving the proper combination of words and music.The actual musical ingredients of the Vespers were not novel to Mantua – concertato had been used by Lodovico Grossi da Viadana, a former choirmaster at the cathedral of Mantua, while the ''Sonata sopra'' had been anticipated by Archangelo Crotti in his ''Sancta Maria'' published in 1608.It is, writes Denis Arnold, Monteverdi's mixture of the various elements that makes the music unique.", "Arnold adds that the Vespers achieved fame and popularity only after their 20th-century rediscovery; they were not particularly regarded in Monteverdi's time.===Madrigals 1614–1638: books 6, 7 and 8=======Sixth book====During his years in Venice Monteverdi published his sixth (1614), seventh (1619) and eighth (1638) books of madrigals.", "The sixth book consists of works written before the composer's departure from Mantua.", "Hans Redlich sees it as a transitional work, containing Monteverdi's last madrigal compositions in the manner of the ''prima pratica'', together with music which is typical of the new style of expression which Monteverdi had displayed in the dramatic works of 1607–08.The central theme of the collection is loss; the best-known work is the five-voice version of the ''Lamento d'Arianna'', which, says Massimo Ossi, gives \"an object lesson in the close relationship between monodic recitative and counterpoint\".", "The book contains Monteverdi's first settings of verses by Giambattista Marino, and two settings of Petrarch which Ossi considers the most extraordinary pieces in the volume, providing some \"stunning musical moments\".====Seventh book====While Monteverdi had looked backwards in the sixth book, he moved forward in the seventh book from the traditional concept of the madrigal, and from monody, in favour of chamber duets.", "There are exceptions, such the two solo ''lettere amorose'' (love letters) \"Se i languidi miei sguardi\" and \"Se pur destina e vole\", written to be performed ''genere rapresentativo'' – acted as well as sung.", "Of the duets which are the main features of the volume, Chew highlights \"Ohimé, dov'è il mio ben, dov'è il mio core\", a romanesca in which two high voices express dissonances above a repetitive bass pattern.", "The book also contains large-scale ensemble works, and the ballet ''Tirsi e Clori''.", "This was the height of Monteverdi's \"Marino period\"; six of the pieces in the book are settings of the poet's verses.", "As Carter puts it, Monteverdi \"embraced Marino's madrigalian kisses and love-bites with ... the enthusiasm typical of the period\".", "Some commentators have opined that the composer should have had better poetic taste.====Eighth book====The eighth book, subtitled ''Madrigali guerrieri, et amorosi ...'' (\"Madrigals of war and love\") is structured in two symmetrical halves, one for \"war\" and one for \"love\".", "Each half begins with a six-voice setting, followed by an equally large-scale Petrarch setting, then a series of duets mainly for tenor voices, and concludes with a theatrical number and a final ballet.", "The \"war\" half contains several items written as tributes to the emperor Ferdinand III, who had succeeded to the Habsburg throne in 1637.Many of Monteverdi's familiar poets – Strozzi, Rinuccini, Tasso, Marino, Guarini – are represented in the settings.It is difficult to gauge when many of the pieces were composed, although the ballet ''Mascherata dell' ingrate'' that ends the book dates back to 1608 and the celebration of the Gonzaga-Savoy marriage.", "The ''Combattimento di Tancredi e Clorinda'', centrepiece of the \"war\" settings, had been written and performed in Venice in 1624; on its publication in the eighth book, Monteverdi explicitly linked it to his concept of ''concitato genera'' (otherwise ''stile concitato'' – \"aroused style\") that would \"fittingly imitate the utterance and the accents of a brave man who is engaged in warfare\", and implied that since he had originated this style, others had begun to copy it.", "The work employed for the first time instructions for the use of pizzicato string chords, and also evocations of fanfares and other sounds of combat.The critic Andrew Clements describes the eighth book as \"a statement of artistic principles and compositional authority\", in which Monteverdi \"shaped and expanded the madrigal form to accommodate what he wanted to do ... the pieces collected in Book Eight make up a treasury of what music in the first half the 17th century could possibly express.", "\"===Other Venetian music: 1614–1638===Mantua at the time of its sacking in 1630During this period of his Venetian residency, Monteverdi composed quantities of sacred music.", "Numerous motets and other short works were included in anthologies by local publishers such as Giulio Cesare Bianchi (a former student of Monteverdi) and Lorenzo Calvi, and others were published elsewhere in Italy and Austria.", "The range of styles in the motets is broad, from simple strophic arias with string accompaniment to full-scale declamations with an alleluia finale.Monteverdi retained emotional and political attachments to the Mantuan court and wrote for it, or undertook to write, large amounts of stage music including at least four operas.", "The ballet ''Tirsi e Clori'' survives through its inclusion in the seventh book, but the rest of the Mantuan dramatic music is lost.", "Many of the missing manuscripts may have disappeared in the wars that overcame Mantua in 1630.The most significant aspect of their loss, according to Carter, is the extent to which they might have provided musical links between Monteverdi's early Mantuan operas and those he wrote in Venice after 1638: \"Without these links ... it is hard to a produce a coherent account of his development as a composer for the stage\".", "Likewise, Janet Beat regrets that the 30-year gap hampers the study of how opera orchestration developed during those critical early years.Apart from the madrigal books, Monteverdi's only published collection during this period was the volume of ''Scherzi musicale'' in 1632.For unknown reasons, the composer's name does not appear on the inscription, the dedication being signed by the Venetian printer Bartolomeo Magni; Carter surmises that the recently ordained Monteverdi may have wished to keep his distance from this secular collection.", "It mixes strophic continuo songs for solo voice with more complex works which employ continuous variation over repeated bass patterns.", "Chew selects the chaconne for two tenors, ''Zefiro torna e di soavi accenti'', as the outstanding item in the collection: \"The greater part of this piece consists of repetitions of a bass pattern which ensures tonal unity of a simple kind, owing to its being framed as a simple cadence in a G major tonal type: over these repetitions, inventive variations unfold in virtuoso passage-work\".=== Late operas and final works ===''Main articles'': ''Il ritorno d'Ulisse in patria''; ''L'incoronazione di Poppea''; ''Selva morale e spirituale''Poppea, represented in a 16th-century paintingThe last years of Monteverdi's life were much occupied with opera for the Venetian stage.", "Richard Taruskin, in his ''Oxford History of Western Music'', gave his chapter on this topic the title \"Opera from Monteverdi to Monteverdi.\"", "This wording, originally proposed humorously by the Italian music historian Nino Pirrotta, is interpreted seriously by Taruskin as indicating that Monteverdi is significantly responsible for the transformation of the opera genre from a private entertainment of the nobility (as with ''Orfeo'' in 1607), to what became a major commercial genre, as exemplified by his opera ''L'incoronazione di Poppea'' (1643).", "His two surviving operatic works of this period, ''Il ritorno d'Ulisse in patria'' and ''L'incoronazione'' are held by Arnold to be the first \"modern\" operas; ''Il ritorno'' is the first Venetian opera to depart from what Ellen Rosand terms \"the mythological pastoral\".", "However, David Johnson in the ''North American Review'' warns audiences not to expect immediate affinity with Mozart, Verdi or Puccini: \"You have to submit yourself to a much slower pace, to a much more chaste conception of melody, to a vocal style that is at first merely like dry declamation and only on repeated hearings begins to assume an extraordinary eloquence.", "\"''Il ritorno'', says Carter, is clearly influenced by Monteverdi's earlier works.", "Penelope's lament in Act I is close in character to the lament from ''L'Arianna'', while the martial episodes recall ''Il combattimento''.", "''Stile concitato'' is prominent in the fight scenes and in the slaying of Penelope's suitors.", "In ''L'incoronazione'', Monteverdi represents moods and situations by specific musical devices: triple metre stands for the language of love; arpeggios demonstrate conflict; ''stile concitato'' represents rage.", "There is continuing debate about how much of the extant ''L'incoronazione'' music is Monteverdi's original, and how much is the work of others (there are, for instance, traces of music by Francesco Cavalli).The ''Selva morale e spirituale'' of 1641, and the posthumous ''Messa et salmi'' published in 1650 (which was edited by Cavalli), are selections of the sacred music that Monteverdi wrote for San Marco during his 30-year tenure – much else was likely written but not published.", "The ''Selva morale'' volume opens with a series of madrigal settings on moral texts, dwelling on themes such as \"the transitory nature of love, earthly rank and achievement, even existence itself\".", "They are followed by a Mass in conservative style (''stile antico''), the high point of which is an extended seven-voice \"Gloria\".", "Scholars believe that this might have been written to celebrate the end of the 1631 plague.", "The rest of the volume is made up of numerous psalm settings, two Magnificats and three ''Salve Reginas''.", "The ''Messa et salmi'' volume includes a ''stile antico'' Mass for four voices, a polyphonic setting of the psalm ''Laetatus Sum'', and a version of the Litany of Lareto that Monteverdi had originally published in 1620.The posthumous ninth book of madrigals was published in 1651, a miscellany dating back to the early 1630s, some items being repeats of previously published pieces, such as the popular duet ''O sia tranquillo il mare'' from 1638.The book includes a trio for three sopranos, \"Come dolce oggi l'auretta\", which is the only surviving music from the 1630 lost opera ''Proserpina rapita''." ], [ "Historical perspective", "In his lifetime Monteverdi enjoyed considerable status among musicians and the public.", "This is evidenced by the scale of his funeral rites: \"With truly royal pomp a catafalque was erected in the Chiesa de Padrini Minori de Frari, decorated all in mourning, but surrounded with so many candles that the church resembled a night sky luminous with stars\".", "This glorification was transitory; Carter writes that in Monteverdi's day, music rarely survived beyond the circumstances of its initial performance and was quickly forgotten along with its creator.", "In this regard Monteverdi fared better than most.", "His operatic works were revived in several cities in the decade following his death; according to Severo Bonini, writing in 1651, every musical household in Italy possessed a copy of the ''Lamento d'Arianna''.The German composer Heinrich Schütz, who had studied in Venice under Giovanni Gabrieli shortly before Monteverdi's arrival there, possessed a copy of ''Il combattimento'' and himself took up elements of the ''stile concitato''.", "On his second visit to Venice in 1628–1629, Arnold believes, Schütz absorbed the concepts of ''basso continuo'' and expressiveness of word-setting, but he opines that Schütz was more directly influenced by the style of the younger generation of Venetian composers, including Grandi and Giovanni Rovetta (the eventual successor to Monteverdi at San Marco).", "Schütz published a first book of ''Symphoniae sacrae'', settings of biblical texts in the style of ''seconda pratica'', in Venice in 1629.", "''Es steh Gott auf'', from his ''Symphoniae sacrae II'', published in Dresden in 1647, contains specific quotations from Monteverdi.After the 1650s, Monteverdi's name quickly disappears from contemporary accounts, his music generally forgotten except for the ''Lamento'', the prototype of a genre that would endure well into the 18th century.The writer Gabriele D'Annunzio, an early 20th-century admirer of MonteverdiInterest in Monteverdi revived in the late 18th and early 19th centuries among music scholars in Germany and Italy, although he was still regarded as essentially a historical curiosity.", "Wider interest in the music itself began in 1881, when Robert Eitner published a shortened version of the ''Orfeo'' score.", "Around this time Kurt Vogel scored the madrigals from the original manuscripts, but more critical interest was shown in the operas, following the discovery of the ''L'incoronazione'' manuscript in 1888 and that of ''Il ritorno'' in 1904.Largely through the efforts of Vincent d'Indy, all three operas were staged in one form or another, during the first quarter of the 20th century: ''L'Orfeo'' in May 1911, ''L'incoronazione'' in February 1913 and ''Il ritorno'' in May 1925.The Italian nationalist poet Gabriele D'Annunzio lauded Monteverdi and in his novel ''Il fuoco'' (1900) wrote of \"''il divino Claudio'' ... what a heroic soul, purely Italian in its essence!\"", "His vision of Monteverdi as the true founder of Italian musical lyricism was adopted by musicians who worked with the regime of Benito Mussolini (1922–1945), including Gian Francesco Malipiero, Luigi Dallapiccola, and , who contrasted Monteverdi with the decadence of the music of Richard Strauss, Claude Debussy and Igor Stravinsky.In the years after the Second World War the operas began to be performed in the major opera houses, and eventually were established in the general repertory.", "The resuscitation of Monteverdi's sacred music took longer; he did not benefit from the Catholic Church's 19th-century revival of Renaissance music in the way that Palestrina did, perhaps, as Carter suggests, because Monteverdi was viewed chiefly as a secular composer.", "It was not until 1932 that the 1610 ''Vespers'' were published in a modern edition, followed by Redlich's revision two years later.", "Modern editions of the ''Selva morale'' and ''Missa e Salmi'' volumes were published respectively in 1940 and 1942.From the 1979 production of ''L'incoronazione di Poppea'' in SpoletoThe revival of public interest in Monteverdi's music gathered pace in the second half of the 20th century, reaching full spate in the general early-music revival of the 1970s, during which time the emphasis turned increasingly towards \"authentic\" performance using historical instruments.", "The magazine ''Gramophone'' notes over 30 recordings of the ''Vespers'' between 1976 and 2011, and 27 of ''Il combattimento di Tancredi e Clorinda'' between 1971 and 2013.Monteverdi's surviving operas are today regularly performed; the website Operabase notes 555 performances of the operas in 149 productions worldwide in the seasons 2011–2016, ranking Monteverdi at 30th position for all composers, and at 8th ranking for Italian opera composers.", "In 1985, Manfred H. Stattkus published an index to Monteverdi's works, the Stattkus-Verzeichnis, (revised in 2006) giving each composition an \"SV\" number, to be used for cataloguing and references.Monteverdi is lauded by modern critics as \"the most significant composer in late Renaissance and early Baroque Italy\"; \"one of the principal composers in the history of Western music\"; and, routinely, as the first great opera composer.", "These assessments reflect a contemporary perspective, since his music was largely unknown to the composers who followed him during an extensive period, spanning more than two centuries after his death.", "It is, as Redlich and others have pointed out, the composers of the 20th and 21st century who have rediscovered Monteverdi and sought to make his music a basis for their own.", "Possibly, as Chew suggests, they are attracted by Monteverdi's reputation as \"a Modern, a breaker of rules, against the Ancients, those who deferred to ancient authority\" – although the composer was, essentially, a pragmatist, \"showing what can only be described as an opportunistic and eclectic willingness to use whatever lay to hand for the purpose\".", "In a letter dated 16 October 1633, Monteverdi appears to endorse the view of himself as a \"modern\": \"I would rather be moderately praised for the new style than greatly praised for the ordinary\".", "However, Chew, in his final summation, sees the composer historically as facing both ways, willing to use modern techniques but while at the same time protective of his status as a competent composer in the ''stile antico''.", "Thus, says Chew, \"his achievement was both retrospective and progressive\".", "Monteverdi represents the late Renaissance era while simultaneously summing up much of the early Baroque.", "\"And in one respect in particular, his achievement was enduring: the effective projection of human emotions in music, in a way adequate for theatre as well as for chamber music.\"" ], [ "References", "===Notes======Citations======Sources===* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Norwich, John Julius (1983).", "''A History of Venice.''", "Harmondsworth, UK: Penguin Books.", "* * * * * * * * * * * * * * * * * * * * * *" ], [ "External links", "* * * Crticial editions of Monteverdi's complete madrigals and arias by the University of Birmingham and the University of Heidelberg*" ] ]
wikipedia
[ [ "Colossus computer" ], [ "Introduction", "'''Colossus''' was a set of computers developed by British codebreakers in the years 1943–1945 to help in the cryptanalysis of the Lorenz cipher.", "Colossus used thermionic valves (vacuum tubes) to perform Boolean and counting operations.", "Colossus is thus regarded as the world's first programmable, electronic, digital computer, although it was programmed by switches and plugs and not by a stored program.Colossus was designed by General Post Office (GPO) research telephone engineer Tommy Flowers to solve a problem posed by mathematician Max Newman at the Government Code and Cypher School (GC&CS) at Bletchley Park.Alan Turing's use of probability in cryptanalysis (see Banburismus) contributed to its design.", "It has sometimes been erroneously stated that Turing designed Colossus to aid the cryptanalysis of the Enigma.", "(Turing's machine that helped decode Enigma was the electromechanical Bombe, not Colossus.", ")The prototype, '''Colossus Mark 1''', was shown to be working in December 1943 and was in use at Bletchley Park by early 1944.An improved '''Colossus Mark 2''' that used shift registers to quintuple the processing speed, first worked on 1 June 1944, just in time for the Normandy landings on D-Day.", "Ten Colossi were in use by the end of the war and an eleventh was being commissioned.", "Bletchley Park's use of these machines allowed the Allies to obtain a vast amount of high-level military intelligence from intercepted radiotelegraphy messages between the German High Command (''OKW'') and their army commands throughout occupied Europe.The existence of the Colossus machines was kept secret until the mid-1970s.", "All but two machines were dismantled into such small parts that their use could not be inferred.", "The two retained machines were eventually dismantled in the 1960s.", "In January 2024, new photos were released by GCHQ that showed re-engineered Colossus in a very different environment from the Bletchley Park buildings, presumably at GCHQ Cheltenham.", "A functioning reconstruction of a Mark 2 Colossus was completed in 2008 by Tony Sale and a team of volunteers; it is on display at The National Museum of Computing on Bletchley Park." ], [ "Purpose and origins", "A Lorenz SZ42 cipher machine with its covers removed at The National Museum of Computing on Bletchley ParkLorenz SZ machines had 12 wheels, each with a different number of cams (or \"pins\").", "Wheel number123456789101112 BP wheel name ''ψ''1 ''ψ''2 ''ψ''3 ''ψ''4 ''ψ''5 ''μ''37 ''μ''61 ''χ''1 ''χ''2 ''χ''3 ''χ''4 ''χ''5 Number of cams (pins)434751535937614131292623The Colossus computers were used to help decipher intercepted radio teleprinter messages that had been encrypted using an unknown device.", "Intelligence information revealed that the Germans called the wireless teleprinter transmission systems ''\"Sägefisch\"'' (sawfish).", "This led the British to call encrypted German teleprinter traffic \"Fish\", and the unknown machine and its intercepted messages \"Tunny\" (tunafish).Before the Germans increased the security of their operating procedures, British cryptanalysts diagnosed how the unseen machine functioned and built an imitation of it called \"British Tunny\".It was deduced that the machine had twelve wheels and used a Vernam ciphering technique on message characters in the standard 5-bit ITA2 telegraph code.", "It did this by combining the plaintext characters with a stream of key characters using the XOR Boolean function to produce the ciphertext.In August 1941, a blunder by German operators led to the transmission of two versions of the same message with identical machine settings.", "These were intercepted and worked on at Bletchley Park.", "First, John Tiltman, a very talented GC&CS cryptanalyst, derived a keystream of almost 4000 characters.", "Then Bill Tutte, a newly arrived member of the Research Section, used this keystream to work out the logical structure of the Lorenz machine.", "He deduced that the twelve wheels consisted of two groups of five, which he named the χ (''chi'') and ψ (''psi'') wheels, the remaining two he called μ (''mu'') or \"motor\" wheels.", "The ''chi'' wheels stepped regularly with each letter that was encrypted, while the ''psi'' wheels stepped irregularly, under the control of the motor wheels.Cams on wheels 9 and 10 showing their raised (active) and lowered (inactive) positions.", "An active cam reversed the value of a bit (0→1 and 1→0).With a sufficiently random keystream, a Vernam cipher removes the natural language property of a plaintext message of having an uneven frequency distribution of the different characters, to produce a uniform distribution in the ciphertext.", "The Tunny machine did this well.", "However, the cryptanalysts worked out that by examining the frequency distribution of the character-to-character changes in the ciphertext, instead of the plain characters, there was a departure from uniformity which provided a way into the system.", "This was achieved by \"differencing\" in which each bit or character was XOR-ed with its successor.", "After Germany surrendered, allied forces captured a Tunny machine and discovered that it was the electromechanical Lorenz SZ (''Schlüsselzusatzgerät'', cipher attachment) in-line cipher machine.In order to decrypt the transmitted messages, two tasks had to be performed.", "The first was \"wheel breaking\", which was the discovery of the cam patterns for all the wheels.", "These patterns were set up on the Lorenz machine and then used for a fixed period of time for a succession of different messages.", "Each transmission, which often contained more than one message, was enciphered with a different start position of the wheels.", "Alan Turing invented a method of wheel-breaking that became known as Turingery.", "Turing's technique was further developed into \"Rectangling\", for which Colossus could produce tables for manual analysis.", "Colossi 2, 4, 6, 7 and 9 had a \"gadget\" to aid this process.The second task was \"wheel setting\", which worked out the start positions of the wheels for a particular message and could only be attempted once the cam patterns were known.", "It was this task for which Colossus was initially designed.", "To discover the start position of the ''chi'' wheels for a message, Colossus compared two character streams, counting statistics from the evaluation of programmable Boolean functions.", "The two streams were the ciphertext, which was read at high speed from a paper tape, and the keystream, which was generated internally, in a simulation of the unknown German machine.", "After a succession of different Colossus runs to discover the likely ''chi''-wheel settings, they were checked by examining the frequency distribution of the characters in the processed ciphertext.", "Colossus produced these frequency counts." ], [ "Decryption processes", "+ Notation plaintext key – the sequence of characters used in binary XOR with the plaintext to give the ciphertext ''chi'' component of key ''psi'' component of key extended ''psi'' – the actual sequence of characters added by the ''psi'' wheels, including those when they do not advance ciphertext de-''chi''—the ciphertext with the ''chi'' component of the key removed any of the above XOR'ed with its successor character or bit the XOR operation Bletchley Park shorthand for telegraphy code ''space'' (zero) Bletchley Park shorthand for telegraphy code ''mark'' (one)By using differencing and knowing that the ''psi'' wheels did not advance with each character, Tutte worked out that trying just two differenced bits (impulses) of the ''chi''-stream against the differenced ciphertext would produce a statistic that was non-random.", "This became known as Tutte's \"1+2 break in\".", "It involved calculating the following Boolean function::::and counting the number of times it yielded \"false\" (zero).", "If this number exceeded a pre-defined threshold value known as the \"set total\", it was printed out.", "The cryptanalyst would examine the printout to determine which of the putative start positions was most likely to be the correct one for the ''chi''-1 and ''chi''-2 wheels.This technique would then be applied to other pairs of, or single, impulses to determine the likely start position of all five ''chi'' wheels.", "From this, the de-''chi'' (D) of a ciphertext could be obtained, from which the ''psi'' component could be removed by manual methods.", "If the frequency distribution of characters in the de-''chi'' version of the ciphertext was within certain bounds, \"wheel setting\" of the ''chi'' wheels was considered to have been achieved, and the message settings and de-''chi'' were passed to the \"Testery\".", "This was the section at Bletchley Park led by Major Ralph Tester where the bulk of the decrypting work was done by manual and linguistic methods.Colossus could also derive the start position of the ''psi'' and motor wheels.", "The feasibility of utilizing this additional capability regularly was made possible in the last few months of the war when there were plenty of Colossi available and the number of Tunny messages had declined." ], [ "Design and construction", "Valves (vacuum tubes) seen on end in a recreation of the Colossus computerColossus was developed for the \"Newmanry\", the section headed by the mathematician Max Newman that was responsible for machine methods against the twelve-rotor Lorenz SZ40/42 on-line teleprinter cipher machine (code-named Tunny, for tunafish).", "The Colossus design arose out of a parallel project that produced a less-ambitious counting machine dubbed \"Heath Robinson\".", "Although the Heath Robinson machine proved the concept of machine analysis for this part of the process, it had serious limitations.", "The electro-mechanical parts were relatively slow and it was difficult to synchronise two looped paper tapes, one containing the enciphered message, and the other representing part of the keystream of the Lorenz machine.", "Also the tapes tended to stretch and break when being read at up to 2000 characters per second.Stepping switch said to be from an original Colossus, presented by the Director of GCHQ to the Director of the NSA to mark the 40th anniversary of the UKUSA Agreement in 1986Tommy Flowers MBE was a senior electrical engineer and Head of the Switching Group at the Post Office Research Station at Dollis Hill.", "Prior to his work on Colossus, he had been involved with GC&CS at Bletchley Park from February 1941 in an attempt to improve the Bombes that were used in the cryptanalysis of the German Enigma cipher machine.", "He was recommended to Max Newman by Alan Turing, who had been impressed by his work on the Bombes.", "The main components of the Heath Robinson machine were as follows.", "* A tape transport and reading mechanism that ran the looped key and message tapes at between 1000 and 2000 characters per second.", "* A combining unit that implemented the logic of Tutte's method.", "* A counting unit that had been designed by C. E. Wynn-Williams of the Telecommunications Research Establishment (TRE) at Malvern, which counted the number of times the logical function returned a specified truth value.Flowers had been brought in to design the Heath Robinson's combining unit.", "He was not impressed by the system of a key tape that had to be kept synchronised with the message tape and, on his own initiative, he designed an electronic machine which eliminated the need for the key tape by having an electronic analogue of the Lorenz (Tunny) machine.", "He presented this design to Max Newman in February 1943, but the idea that the one to two thousand thermionic valves (vacuum tubes and thyratrons) proposed, could work together reliably, was greeted with great scepticism, so more Robinsons were ordered from Dollis Hill.", "Flowers, however, knew from his pre-war work that most thermionic valve failures occurred as a result of the thermal stresses at power-up, so not powering a machine down reduced failure rates to very low levels.", "Additionally, if the heaters were started at a low voltage then slowly brought up to full voltage, thermal stress was reduced.", "The valves themselves could be soldered-in to avoid problems with plug-in bases, which could be unreliable.", "Flowers persisted with the idea and obtained support from the Director of the Research Station, W Gordon Radley.Flowers and his team of some fifty people in the switching group spent eleven months from early February 1943 designing and building a machine that dispensed with the second tape of the Heath Robinson, by generating the wheel patterns electronically.", "Flowers used some of his own money for the project.", "This prototype, Mark 1 Colossus, contained 1,600 thermionic valves (tubes).", "It performed satisfactorily at Dollis Hill on 8 December 1943 and was dismantled and shipped to Bletchley Park, where it was delivered on 18 January and re-assembled by Harry Fensom and Don Horwood.", "It was operational in January and it successfully attacked its first message on 5 February 1944.It was a large structure and was dubbed 'Colossus'.A memo held in the National Archives written by Max Newman on 18 January 1944 records that \"Colossus arrives today\".During the development of the prototype, an improved design had been developed – the Mark 2 Colossus.", "Four of these were ordered in March 1944 and by the end of April the number on order had been increased to twelve.", "Dollis Hill was put under pressure to have the first of these working by 1 June.", "Allen Coombs took over leadership of the production Mark 2 Colossi, the first of which – containing 2,400 valves – became operational at 08:00 on 1 June 1944, just in time for the Allied Invasion of Normandy on D-Day.", "Subsequently, Colossi were delivered at the rate of about one a month.", "By the time of V-E Day there were ten Colossi working at Bletchley Park and a start had been made on assembling an eleventh.", "Seven of the Colossi were used for 'wheel setting' and three for 'wheel breaking'.Colossus 10 with its extended bedstead in Block H at Bletchley Park in the space now containing the Tunny gallery of The National Museum of Computing The main units of the Mark 2 design were as follows.", "* A tape transport with an 8-photocell reading mechanism.", "* A six character FIFO shift register.", "* Twelve thyratron ring stores that simulated the Lorenz machine generating a bit-stream for each wheel.", "* Panels of switches for specifying the program and the \"set total\".", "* A set of functional units that performed Boolean operations.", "* A \"span counter\" that could suspend counting for part of the tape.", "* A master control that handled clocking, start and stop signals, counter readout and printing.", "* Five electronic counters.", "* An electric typewriter.Most of the design of the electronics was the work of Tommy Flowers, assisted by William Chandler, Sidney Broadhurst and Allen Coombs; with Erie Speight and Arnold Lynch developing the photoelectric reading mechanism.", "Coombs remembered Flowers, having produced a rough draft of his design, tearing it into pieces that he handed out to his colleagues for them to do the detailed design and get their team to manufacture it.", "The Mark 2 Colossi were both five times faster and were simpler to operate than the prototype.Data input to Colossus was by photoelectric reading of a paper tape transcription of the enciphered intercepted message.", "This was arranged in a continuous loop so that it could be read and re-read multiple times – there being no internal storage for the data.", "The design overcame the problem of synchronizing the electronics with the speed of the message tape by generating a clock signal from reading its sprocket holes.", "The speed of operation was thus limited by the mechanics of reading the tape.", "During development, the tape reader was tested up to 9700 characters per second (53 mph) before the tape disintegrated.", "So 5000 characters/second () was settled on as the speed for regular use.", "Flowers designed a 6-character shift register, which was used both for computing the delta function (ΔZ) and for testing five different possible starting points of Tunny's wheels in the five processors.", "This five-way parallelism enabled five simultaneous tests and counts to be performed giving an effective processing speed of 25,000 characters per second.", "The computation used algorithms devised by W. T. Tutte and colleagues to decrypt a Tunny message." ], [ "Operation", "Colossus selection panel showing selections amongst others, of the far tape on the bedstead, and for input to the algorithm: Δ'''Z''', Δ and Δ.The Newmanry was staffed by cryptanalysts, operators from the Women's Royal Naval Service (WRNS) – known as \"Wrens\" – and engineers who were permanently on hand for maintenance and repair.", "By the end of the war the staffing was 272 Wrens and 27 men.The first job in operating Colossus for a new message was to prepare the paper tape loop.", "This was performed by the Wrens who stuck the two ends together using Bostik glue, ensuring that there was a 150-character length of blank tape between the end and the start of the message.", "Using a special hand punch they inserted a start hole between the third and fourth channels sprocket holes from the end of the blank section, and a stop hole between the fourth and fifth channels sprocket holes from the end of the characters of the message.", "These were read by specially positioned photocells and indicated when the message was about to start and when it ended.", "The operator would then thread the paper tape through the gate and around the pulleys of the bedstead and adjust the tension.", "The two-tape bedstead design had been carried on from Heath Robinson so that one tape could be loaded whilst the previous one was being run.", "A switch on the Selection Panel specified the \"near\" or the \"far\" tape.After performing various resetting and zeroizing tasks, the Wren operators would, under instruction from the cryptanalyst, operate the \"set total\" decade switches and the K2 panel switches to set the desired algorithm.", "They would then start the bedstead tape motor and lamp and, when the tape was up to speed, operate the master start switch." ], [ "Programming", "Colossus K2 switch panel showing switches for specifying the algorithm (on the left) and the counters to be selected (on the right).Colossus 'set total' switch panelHoward Campaigne, a mathematician and cryptanalyst from the US Navy's OP-20-G, wrote the following in a foreword to Flowers' 1983 paper \"The Design of Colossus\".Colossus was not a stored-program computer.", "The input data for the five parallel processors was read from the looped message paper tape and the electronic pattern generators for the ''chi'', ''psi'' and motor wheels.", "The programs for the processors were set and held on the switches and jack panel connections.", "Each processor could evaluate a Boolean function and count and display the number of times it yielded the specified value of \"false\" (0) or \"true\" (1) for each pass of the message tape.Input to the processors came from two sources, the shift registers from tape reading and the thyratron rings that emulated the wheels of the Tunny machine.", "The characters on the paper tape were called '''Z''' and the characters from the Tunny emulator were referred to by the Greek letters that Bill Tutte had given them when working out the logical structure of the machine.", "On the selection panel, switches specified either '''Z''' or '''ΔZ''', either or '''Δ''' and either or '''Δ''' for the data to be passed to the jack field and 'K2 switch panel'.", "These signals from the wheel simulators could be specified as stepping on with each new pass of the message tape or not.The K2 switch panel had a group of switches on the left-hand side to specify the algorithm.", "The switches on the right-hand side selected the counter to which the result was fed.", "The plugboard allowed less specialized conditions to be imposed.", "Overall the K2 switch panel switches and the plugboard allowed about five billion different combinations of the selected variables.", "As an example: a set of runs for a message tape might initially involve two ''chi'' wheels, as in Tutte's 1+2 algorithm.", "Such a two-wheel run was called a long run, taking on average eight minutes unless the parallelism was utilised to cut the time by a factor of five.", "The subsequent runs might only involve setting one ''chi'' wheel, giving a short run taking about two minutes.", "Initially, after the initial long run, the choice of the next algorithm to be tried was specified by the cryptanalyst.", "Experience showed, however, that decision trees for this iterative process could be produced for use by the Wren operators in a proportion of cases." ], [ "Influence and fate", "Although the Colossus was the first of the electronic digital machines with programmability, albeit limited by modern standards, it was not a general-purpose machine, being designed for a range of cryptanalytic tasks, most involving counting the results of evaluating Boolean algorithms.A Colossus computer was thus not a fully Turing complete machine.", "However, University of San Francisco professor Benjamin Wells has shown that if all ten Colossus machines made were rearranged in a specific cluster, then the entire set of computers could have simulated a universal Turing machine, and thus be Turing complete.Colossus and the reasons for its construction were highly secret and remained so for 30 years after the War.", "Consequently, it was not included in the history of computing hardware for many years, and Flowers and his associates were deprived of the recognition they were due.", "All but two of the Colossi were dismantled after the war and parts returned to the Post Office.", "Some parts, sanitised as to their original purpose, were taken to Max Newman's Royal Society Computing Machine Laboratory at Manchester University.", "Two Colossi, along with two Tunny machines, were retained and moved to GCHQ's new headquarters at Eastcote in April 1946, and then to Cheltenham between 1952 and 1954.One of the Colossi, known as ''Colossus Blue'', was dismantled in 1959; the other in the 1960s.", "Tommy Flowers was ordered to destroy all documentation.", "He duly burnt them in a furnace and later said of that order:The Colossi were adapted for other purposes, with varying degrees of success; in their later years they were used for training.", "Jack Good related how he was the first to use Colossus after the war, persuading the US National Security Agency that it could be used to perform a function for which they were planning to build a special-purpose machine.", "Colossus was also used to perform character counts on one-time pad tape to test for non-randomness.A small number of people who were associated with Colossus—and knew that large-scale, reliable, high-speed electronic digital computing devices were feasible—played significant roles in early computer work in the UK and probably in the US.", "However, being so secret, it had little direct influence on the development of later computers; it was EDVAC that was the seminal computer architecture of the time.", "In 1972, Herman Goldstine, who was unaware of Colossus and its legacy to the projects of people such as Alan Turing (ACE), Max Newman (Manchester computers) and Harry Huskey (Bendix G-15), wrote that,Professor Brian Randell, who unearthed information about Colossus in the 1970s, commented on this, saying that:Randell's efforts started to bear fruit in the mid-1970s.", "The secrecy about Bletchley Park had been broken when Group Captain Winterbotham published his book ''The Ultra Secret'' in 1974.Randell was researching the history of computer science in Britain for a conference on the history of computing held at the Los Alamos Scientific Laboratory, New Mexico on 10–15 June 1976, and got permission to present a paper on wartime development of the COLOSSI at the Post Office Research Station, Dollis Hill (in October 1975 the British Government had released a series of captioned photographs from the Public Record Office).", "The interest in the \"revelations\" in his paper resulted in a special evening meeting when Randell and Coombs answered further questions.", "Coombs later wrote that ''no member of our team could ever forget the fellowship, the sense of purpose and, above all, the breathless excitement of those days''.", "In 1977 Randell published an article ''The First Electronic Computer'' in several journals.", "In October 2000, a 500-page technical report on the Tunny cipher and its cryptanalysis—entitled ''General Report on Tunny''—was released by GCHQ to the national Public Record Office, and it contains a fascinating paean to Colossus by the cryptographers who worked with it:" ], [ "Reconstruction", "Tony Sale (right) reconstructed a Colossus Mark II at Bletchley Park.", "Here, in 2006, Sale supervises the breaking of an enciphered message with the completed machine.A team led by Tony Sale built a fully functional reconstruction of a Colossus Mark 2 between 1993 and 2008.In spite of the blueprints and hardware being destroyed, a surprising amount of material had survived, mainly in engineers' notebooks, but a considerable amount of it in the U.S.", "The optical tape reader might have posed the biggest problem, but Dr. Arnold Lynch, its original designer was able to redesign it to his own original specification.", "The reconstruction is on display, in the historically correct place for Colossus No.", "9, at The National Museum of Computing, in H Block Bletchley Park in Milton Keynes, Buckinghamshire.In November 2007, to celebrate the project completion and to mark the start of a fundraising initiative for The National Museum of Computing, a Cipher Challenge pitted the rebuilt Colossus against radio amateurs worldwide in being first to receive and decode three messages enciphered using the Lorenz SZ42 and transmitted from radio station DL0HNF in the ''Heinz Nixdorf MuseumsForum'' computer museum.", "The challenge was easily won by radio amateur Joachim Schüth, who had carefully prepared for the event and developed his own signal processing and code-breaking code using Ada.", "The Colossus team were hampered by their wish to use World War II radio equipment, delaying them by a day because of poor reception conditions.", "Nevertheless, the victor's 1.4 GHz laptop, running his own code, took less than a minute to find the settings for all 12 wheels.", "The German codebreaker said: \"My laptop digested ciphertext at a speed of 1.2 million characters per second—240 times faster than Colossus.", "If you scale the CPU frequency by that factor, you get an equivalent clock of 5.8 MHz for Colossus.", "That is a remarkable speed for a computer built in 1944.", "\"The Cipher Challenge verified the successful completion of the rebuilding project.", "\"On the strength of today's performance Colossus is as good as it was six decades ago\", commented Tony Sale.", "\"We are delighted to have produced a fitting tribute to the people who worked at Bletchley Park and whose brainpower devised these fantastic machines which broke these ciphers and shortened the war by many months.", "\"Front view of the Colossus reconstruction showing, from right to left (1) The \"bedstead\" containing the message tape in its continuous loop and with a second one loaded.", "(2) The J-rack containing the Selection Panel and Plug Panel.", "(3) The K-rack with the large \"Q\" switch panel and sloping patch panel.", "(4) The double S-rack containing the control panel and, above the image of a postage stamp, five two-line counter displays.", "(5) The electric typewriter in front of the five sets of four \"set total\" decade switches in the C-rack." ], [ "Other meanings", "There was a fictional computer named ''Colossus'' in the 1970 film ''Colossus: The Forbin Project'' which was based on the 1966 novel ''Colossus'' by D. F. Jones.", "This was a coincidence as it pre-dates the public release of information about Colossus, or even its name.Neal Stephenson's novel ''Cryptonomicon'' (1999) also contains a fictional treatment of the historical role played by Turing and Bletchley Park." ], [ "See also", "* History of computing hardware* List of vacuum-tube computers* Manchester Baby* Z3* Z4" ], [ "Footnotes" ], [ "References", "* * * in * * * * * * in * in * in * in * * in * Updated and extended version of ''Action This Day: From Breaking of the Enigma Code to the Birth of the Modern Computer'' Bantam Press 2001* in * * in * * * * ** ** ** ** * * * * * * * in * * describes the operation of Colossus in breaking Tunny messages* in * * in" ], [ "Further reading", "* * A short film made by Google to celebrate Colossus and those who built it, in particular Tommy Flowers.", "* – A detailed description of the cryptanalysis of Tunny, and some details of Colossus (contains some minor errors)* :::A guided tour of the history and geography of the Park, written by one of the founder members of the Bletchley Park Trust* * * – Comparison of the first computers, with a chapter about Colossus and its reconstruction by Tony Sale.", "* A slender (20-page) booklet, containing the same material as Tony Sale's website (see below)*" ], [ "External links", "* Early computer development* The National Museum of Computing (TNMOC)** TNMOC: The 75th anniversary of the first attack* Tony Sale's Codes and Ciphers Contains a great deal of information, including:** Colossus, the revolution in code breaking** Lorenz Cipher and the Colossus*** The machine age comes to Fish codebreaking*** The Colossus Rebuild Project*** The Colossus Rebuild Project: Evolving to the Colossus Mk 2*** Walk around Colossus A detailed tour of the replica Colossus – make sure to click on the \"More Text\" links on each image to see the informative detailed text about that part of Colossus** IEEE lecture – Transcript of a lecture Tony Sale gave describing the reconstruction project* Brian Randell's 1976 lecture on the Colossus* BBC news article reporting on the replica Colossus* BBC news article: \"Colossus cracks codes once more\"* BBC news article: BBC news article: \"Bletchley's code-cracking Colossus\" with video interviews 2010-02-02* Website on Copeland's 2006 book with much information and links to recently declassified information* Was the Manchester Baby conceived at Bletchley Park?", "* * online virtual simulation of Colossus" ] ]
wikipedia
[ [ "Canadian Shield" ], [ "Introduction", "The '''Canadian Shield''' ( ), also called the '''Laurentian Plateau''', is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks.", "It forms the North American Craton (or Laurentia), the ancient geologic core of the North American continent.", "Glaciation has left the area with only a thin layer of soil, through which exposures of igneous bedrock resulting from its long volcanic history are frequently visible.", "As a deep, common, joined bedrock region in eastern and central Canada, the shield stretches north from the Great Lakes to the Arctic Ocean, covering over half of Canada and most of Greenland; it also extends south into the northern reaches of the United States." ], [ "Geographical extent", "The Canadian Shield is a physiographic division comprising four smaller physiographic provinces: the Laurentian Upland, Kazan Region, Davis and James.", "The shield extends into the United States as the Adirondack Mountains (connected by the Frontenac Axis) and the Superior Upland.", "The Canadian Shield is a U-shaped subsection of the Laurentia craton signifying the area of greatest glacial impact (scraping down to bare rock) creating the thin soils.", "The age of the Canadian Shield is estimated to be 4.28 Ga.", "The Canadian Shield once had jagged peaks, higher than any of today's mountains, but millions of years of erosion have changed these mountains to rolling hills.The Canadian Shield is a collage of Archean plates and accreted juvenile arc terranes and sedimentary basins of the Proterozoic Eon that were progressively amalgamated during the interval 2.45–1.24 Ga, with the most substantial growth period occurring during the Trans-Hudson orogeny, between c. 1.90–1.80 Ga.", "The Canadian Shield was the first part of North America to be permanently elevated above sea level and has remained almost wholly untouched by successive encroachments of the sea upon the continent.", "It is the Earth's greatest area of exposed Archean rock.", "The metamorphic base rocks are mostly from the Precambrian (between 4.5 Ga and 540 Ma) and have been repeatedly uplifted and eroded.", "Today it consists largely of an area of low relief above sea level with a few monadnocks and low mountain ranges (including the Laurentian Mountains) probably eroded from the plateau during the Cenozoic Era.", "During the Pleistocene Epoch, continental ice sheets depressed the land surface (creating Hudson Bay) but also tilted up its northeastern \"rim\" (the Torngat), scooped out thousands of lake basins, and carried away much of the region's soil.", "The northeastern portion, however, became tilted up so that, in northern Labrador and Baffin Island, the land rises to more than 1,500 metres (5,000 feet) above sea level.When the Greenland section is included, the Canadian Shield is approximately circular, bounded on the northeast by the northeast edge of Greenland, with Hudson Bay in the middle.", "It covers much of Greenland, all of Labrador and the Great Northern Peninsula of Newfoundland, most of Quebec north of the St. Lawrence River, much of Ontario including northern sections of the Ontario Peninsula, the Adirondack Mountains of New York, the northernmost part of Lower Michigan and all of Upper Michigan, northern Wisconsin, northeastern Minnesota, the central and northern portions of Manitoba, northern Saskatchewan, a small portion of northeastern Alberta, mainland Northwest Territories to the east of a line extended north from the Saskatchewan-Alberta border, most of Nunavut's mainland and, of its Arctic Archipelago, Baffin Island and significant bands through Somerset, Southampton, Devon and Ellesmere islands.", "In total, the exposed area of the shield covers approximately .", "The true extent of the shield is greater still and stretches from the Western Cordillera in the west to the Appalachians in the east and as far south as Texas, but these regions are overlaid with much younger rocks and sediment." ], [ "Geology", "The Canadian Shield is among the oldest on Earth, with regions dating from 2.5 to 4.2 billion years.", "The multitude of rivers and lakes in the region is classical example of a deranged drainage system, caused by the watersheds of the area being disturbed by glaciation and the effect of post-glacial rebound.", "The shield was originally an area of very large, very tall mountains (about ) with much volcanic activity, but the area was eroded to nearly its current topographic appearance of relatively low relief over 500 Ma.", "Erosion has exposed the roots of the mountains, which take the form of greenstone belts in which belts of volcanic rock that have been altered by metamorphism are surrounded by granitic rock.", "These belts range in age from 3.6 to 2.7 Ga. Much of the granitic rock belongs to the distinctive tonalite–trondhjemite–granodiorite family of rocks, which are characteristic of Archean continental crust.", "Many of Canada's major ore deposits are associated with greenstone belts.The Sturgeon Lake Caldera in Kenora District, Ontario, is one of the world's best preserved mineralized Neoarchean caldera complexes, which is 2.7 Ga.", "The Canadian Shield also contains the Mackenzie dike swarm, which is the largest dike swarm known on Earth.", "The North American craton is the bedrock forming the heart of the North American continent, and the Canadian Shield is the largest exposed part of the craton's bedrock.", "The Canadian Shield is part of an ancient continent called Arctica, which was formed about 2.5 Ga during the Neoarchean era.Mountains have deep roots and float on the denser mantle much like an iceberg at sea.", "As mountains erode, their roots rise and are eroded in turn.", "The rocks that now form the surface of the shield were once far below the Earth's surface.", "The high pressures and temperatures at those depths provided ideal conditions for mineralization.", "Although these mountains are now heavily eroded, many large mountains still exist in Canada's far north called the Arctic Cordillera.", "This is a vast, deeply dissected mountain range, stretching from northernmost Ellesmere Island to the northernmost tip of Labrador.", "The range's highest peak is Nunavut's Barbeau Peak at above sea level.", "Precambrian rock is the major component of the bedrock.Image:Temagami greenstone belt pillow lava.jpg|Weathered Precambrian pillow lava in the Temagami Greenstone BeltFile:Nature's Art created by thousands of years of erosion by ice.jpg|Folded Precambrian gneiss of the Canadian Shield in Georgian Bay, OntarioImage:Canadian Shield Ontario.jpg|Typical Canadian Shield landscape: spruce, lakes, bogs, and rock" ], [ "Ecology", "Typical shield landscape in a southern Ontario region with very few old growth trees, due to a history of logging and fires.", "Black River, Queen Elizabeth II Wildlands Provincial Park.The current surface expression of the shield is one of very thin soil lying on top of the bedrock, with many bare outcrops.", "This arrangement was caused by severe glaciation during the ice ages that covered the shield and scraped the rock clean.", "The lowlands of the Canadian Shield have a very dense soil that is not suitable for forestation; it also contains many marshes and bogs (muskegs).", "The rest of the region has coarse soil that does not retain moisture well and is frozen with permafrost throughout the year.", "Forests are not as dense in the north.The shield is covered in parts by vast boreal forests in the south that support natural ecosystems as well as a major logging industry.", "The boreal forest area gives way to the Eastern Canadian Shield taiga that covers northern Quebec and most of Labrador.", "The Midwestern Canadian Shield forests that run westwards from Northwestern Ontario have boreal forests that give way to taiga in the most northerly parts of Manitoba and Saskatchewan.", "Hydrologic drainage is generally poor, the soil compacting effects of glaciation being one of the many causes.", "Tundra typically prevails in the northern regions.", "Many mammals such as caribou, white-tailed deer, moose, wolves, wolverines, weasels, mink, otters, grizzly bear, polar bears and black bears are present.", "In the case of polar bears (), the shield area contains many of their denning locations, such as the Wapusk National Park.The many lakes and rivers on the shield contain a plentiful quantity of different sports fish species, including walleye, northern pike, lake trout, yellow perch, whitefish, brook trout, arctic grayling, and many types of baitfish.", "The water surfaces are also home to many waterfowl, most notably Canada geese, loons and gulls.", "The vast forests contain a myriad population of other birds, including ravens and crows, predatory birds and many songbirds." ], [ "Mining and economics", "The Canadian Shield is one of the world's richest areas in terms of mineral ores.", "It is filled with substantial deposits of nickel, gold, silver, and copper.", "There are many mining towns extracting these minerals.", "The largest, and one of the best known, is Sudbury, Ontario.", "Sudbury is an exception to the normal process of forming minerals in the shield since the Sudbury Basin is an ancient meteorite impact crater.", "Ejecta from the meteorite impact was found in the Rove Formation in May 2007.The nearby but less-known Temagami Magnetic Anomaly has striking similarities to the Sudbury Basin.", "This suggests it could be a second metal-rich impact crater.", "In northeastern Quebec, the giant Manicouagan Reservoir is the site of an extensive hydroelectric project (Manic-cinq, or Manic-5).", "This is one of the largest-known meteorite impact craters on Earth, though not as large as the Sudbury crater.The Flin Flon greenstone belt in central Manitoba and east-central Saskatchewan \"is one of the largest Paleoproterozoic volcanic-hosted massive sulfide (VMS) districts in the world, containing 27 copper-zinc-(gold) deposits from which more than 183 million tonnes of sulfide have been mined.\"", "The portion in the Northwest Territories has recently been the site of several major diamond discoveries.", "The kimberlite pipes in which the diamonds are found are closely associated with cratons, which provide the deep lithospheric mantle required to stabilize diamond as a mineral.", "The kimberlite eruptions then bring the diamonds from over depth to the surface.", "The Ekati and Diavik mines are actively mining kimberlite diamonds." ], [ "See also", "* Baltic Shield* Athabasca Basin* Geology of Ontario* Platform (geology)* Basement (geology)* Volcanology of Canada* Wisconsin glaciation* Glacial history of Minnesota" ], [ "References" ], [ "Further reading", "* Schwartzenberger, Tina (2005), '' The Canadian Shield'', Weigl Educational," ] ]
wikipedia
[ [ "Comic book" ], [ "Introduction", "Comic books on display at a museum, depicting how they would have been displayed at a rail station store in the first half of the 20th century.A common comic-book cover format displays the issue number, date, price and publisher along with an illustration and cover copy which may include a story's title.A '''comic book''', also called '''comicbook''', '''comic magazine''' or simply '''comic''', is a publication that consists of comics art in the form of sequential juxtaposed panels that represent individual scenes.", "Panels are often accompanied by descriptive prose and written narrative, usually, dialogue contained in word balloons emblematic of the comics art form.", "\"Comic Cuts\" was a British comic published from 1890 to 1953.It was preceded by \"Ally Sloper's Half Holiday\" (1884) which is notable for its use of sequential cartoons to unfold narrative.", "These British comics existed alongside the popular lurid \"Penny dreadfuls\" (such as \"Spring-heeled Jack\"), boys' \"Story papers\" and the humorous Punch (magazine) which was the first to use the term \"cartoon\" in its modern sense of a humorous drawing.", "The interweaving of drawings and the written word had been pioneered by, among others, William Blake (1757 - 1857) in works such as Blake's \"The Descent Of Christ\" (1804 - 1820).The first modern (American style) comic book, ''Famous Funnies'', was released in the US in 1934 and was a reprinting of earlier newspaper humor comic strips, which had established many of the story-telling devices used in comics.", "The term ''comic book'' derives from American comic books once being a compilation of comic strips of a humorous tone; however, this practice was replaced by featuring stories of all genres, usually not humorous in tone.The largest comic book market is Japan.", "By 1995, the manga market in Japan was valued at (), with annual sales of 1.9billion manga books ( volumes and manga magazines) in Japan, equivalent to 15issues per person.", "In 2020 the manga market in Japan reached a new record value of ¥612.5 billion due to a fast growth of digital manga sales as well as an increase in print sales.", "The comic book market in the United States and Canada was valued at in 2016., the largest comic book publisher in the United States is manga distributor Viz Media, followed by DC Comics and Marvel Comics the original feature full length special edition franchises including Superman, Batman, Wonder Woman, Spider-Man, the Incredible Hulk and the X-Men.", "The best-selling comic book categories in the US are juvenile children's fiction at 41%, manga at 28% and superhero comics at 10% of the market.", "Another major comic book market is France, where Franco-Belgian comics and Japanese manga each represent 40% of the market, followed by American comics at 10% market share." ], [ "Structure", "Comic books heavily rely on their organization and visual presentation.", "Authors dedicate significant attention to aspects like page layout, size, orientation, and the positioning of panels.", "These characteristics are crucial for effectively conveying the content and messages within the comic book.", "Key components of comic books encompass panels, speech bubbles (also known as balloons), text lines, and characters.", "Speech balloons generally take the form of convex containers that hold character dialogue and are connected to the character via a tail element.", "The tail comprises an origin, path, tip, and directional point.", "The creation of comic books involves several essential steps: writing, drawing, and coloring.", "Various technological tools and methods are employed to craft comic books, incorporating concepts such as directions, axes, data, and metrics.", "Following these formatting guidelines, the process unfolds with writing, drawing, and coloring.", "In the United States, the term \"comic book\", is generally used for comics periodicals and trade paperbacks while \"graphic novel\" is the term used for standalone books." ], [ "American comic books", "Comics as a print medium have existed in the United States since the printing of ''The Adventures of Mr. Obadiah Oldbuck'' in 1842 in hardcover, making it the first known American prototype comic book.", "Proto-comics periodicals began appearing early in the 20th century, with the first comic standard-sized comic being ''Funnies on Parade''.", "''Funnies on Parades'' was the first book that established the size, duration, and format of the modern comic book.", "Following this was, Dell Publishing's 36-page ''Famous Funnies: A Carnival of Comics'' as the first true newsstand American comic book; Goulart, for example, calls it \"the cornerstone for one of the most lucrative branches of magazine publishing\".", "In 1905 G.W.", "Dillingham Company published 24 select strips by the cartoonist Gustave Verbeek in an anthology book called 'The Incredible Upside-Downs of Little Lady Lovekins and Old Man Muffaroo'.", "The introduction of Jerry Siegel and Joe Shuster's Superman in 1938 turned comic books into a major industry and ushered in the Golden Age of Comic Books.", "The Golden Age originated the archetype of the superhero.", "According to historian Michael A. Amundson, appealing comic-book characters helped ease young readers' fear of nuclear war and neutralize anxiety about the questions posed by atomic power.Historians generally divide the timeline of the American comic book into eras.", "The Golden Age of Comic Books began in 1938, with the debut of Superman in Action Comics #1, published by Detective Comics (predecessor of DC Comics), which is generally considered the beginning of the modern comic book as it is known today.", "The Silver Age of Comic Books is generally considered to date from the first successful revival of the then-dormant superhero form, with the debut of the Flash in ''Showcase'' #4 (Oct. 1956).", "The Silver Age lasted through the late 1960s or early 1970s, during which time Marvel Comics revolutionized the medium with such naturalistic superheroes as Stan Lee and Jack Kirby's Fantastic Four and Lee and Steve Ditko's Spider-Man.", "The demarcation between the Silver Age and the following era, the Bronze Age of Comic Books, is less well-defined, with the Bronze Age running from the very early 1970s through the mid-1980s.", "The Modern Age of Comic Books runs from the mid-1980s to the present day.A significant event in the timeline of American comic books occurred when psychiatrist Fredric Wertham voiced his criticisms of the medium through his book ''Seduction of the Innocent'' (1954).", "This critique led to the involvement of the American Senate Subcommittee on Juvenile Delinquency, which launched an investigation into comic books.", "Wertham argued that comic books were accountable for a surge in juvenile delinquency and posed a potential impact on a child's sexuality and moral values.", "In response to attention from the government and from the media, the US comic book industry set up the Comics Magazine Association of America.", "The CMAA instilled the Comics Code Authority in 1954 and drafted the self-censorship Comics Code that year, which required all comic books to go through a process of approval.", "It was not until the 1970s that comic books could be published without passing through the inspection of the CMAA.", "The Code was made formally defunct in November 2011.=== Underground comic books ===In the late 1960s and early 1970s, a surge of creativity emerged in what became known as underground comics.", "Published and distributed independently of the established comics industry, most of such comics reflected the youth counterculture and drug culture of the time.", "Underground comix \"reflected and commented on the social divisions and tensions of American society\".", "Many had an uninhibited, often irreverent style; their frank depictions of nudity, sex, profanity, and politics had no parallel outside their precursors, the pornographic and even more obscure \"Tijuana bibles\".", "Underground comics were almost never sold at newsstands, but rather in such youth-oriented outlets as head shops and record stores, as well as by mail order.", "The underground comics encouraged creators to publish their work independently so that they would have full ownership rights to their characters.Frank Stack's ''The Adventures of Jesus'', published under the name Foolbert Sturgeon, has been credited as the first underground comic; while R. Crumb and the crew of cartoonists who worked on ''Zap Comix'' popularized the form.===Alternative comics===The rise of comic book specialty stores in the late 1970s created and paralleled a dedicated market for \"independent\" or \"alternative comics\" in the US.", "The first such comics included the anthology series ''Star Reach'', published by comic book writer Mike Friedrich from 1974 to 1979, and Harvey Pekar's ''American Splendor'', which continued sporadic publication into the 21st century and which Shari Springer Berman and Robert Pulcini adapted into a 2003 film.", "Some independent comics continued in the tradition of underground comics.", "While their content generally remained less explicit, others resembled the output of mainstream publishers in format and genre but were published by smaller artist-owned companies or by single artists.", "A few (notably ''RAW'') represented experimental attempts to bring comics closer to the status of fine art.During the 1970s the \"small press\" culture grew and diversified.", "By the 1980s, several independent publishers – such as Pacific, Eclipse, First, Comico, and Fantagraphics – had started releasing a wide range of styles and formats—from color-superhero, detective, and science-fiction comic books to black-and-white magazine-format stories of Latin American magical realism.A number of small publishers in the 1990s, changed the format and distribution of their comics to more closely resemble non-comics publishing.", "The \"minicomics\" form, an extremely informal version of self-publishing, arose in the 1980s and became increasingly popular among artists in the 1990s, despite reaching an even more limited audience than the small press.Small publishers regularly releasing titles include Avatar Press, Hyperwerks, Raytoons, and Terminal Press, buoyed by such advances in printing technology as digital print-on-demand.===Graphic novels===The Centers for Disease Control and Prevention published this instructional graphic novel in 2018 to keep youth from spreading infectious diseasesIn 1964, Richard Kyle coined the term \"graphic novel\".", "Precursors of the form existed by the 1920s, which saw a revival of the medieval woodcut tradition by Belgian Frans Masereel, American Lynd Ward and others, including Stan Lee.In 1947, Fawcett Publications published \"Comics Novel No.", "1\", as the first in an intended series of these \"comics novels\".", "The story in the first issue was \"Anarcho, Dictator of Death\", a five chapter spy genre tale written by Otto Binder and drawn by Al Carreno.", "It is readable online in the Digital Comic Museum.", "The magazine never reached a second issue.", "In 1950, St. John Publications produced the digest-sized, adult-oriented \"picture novel\" ''It Rhymes with Lust'', a 128-page digest by pseudonymous writer \"Drake Waller\" (Arnold Drake and Leslie Waller), penciler Matt Baker and inker Ray Osrin, touted as \"an original full-length novel\" on its cover.", "\"It Rhymes with Lust\" is also available to read online in the Digital Comic Museum.In 1971, writer-artist Gil Kane and collaborators applied a paperback format to their \"comics novel\" ''Blackmark''.", "Will Eisner popularized the term \"graphic novel\" when he used it on the cover of the paperback edition of his work ''A Contract with God, and Other Tenement Stories'' in 1978 and, subsequently, the usage of the term began to increase.===Digital comics======Market size===In 2017, the comic book market size for North America was just over $1 billion with digital sales being flat, book stores having a 1 percent decline, and comic book stores having a 10 percent decline over 2016.The global comic book market saw a substantial 12% growth in 2020, reaching a total worth of USD 8.49 billion.", "This positive trajectory continued in 2021, with the market's annual valuation surging to USD 9.21 billion.", "The rising popularity of comic books can be attributed to heightened global interest, driven significantly by collaborative efforts among diverse brands.", "These collaborations are geared towards producing more engaging and appealing comic content, contributing to the industry's continued growth.===Comic book collecting===The 1970s saw the advent of specialty comic book stores.", "Initially, comic books were marketed by publishers to children because comic books were perceived as children's entertainment.", "However, with increasing recognition of comics as an art form and the growing pop culture presence of comic book conventions, they are now embraced by many adults.Comic book collectors often exhibit a lifelong passion for the stories within comics, often focusing on specific superheroes and striving to gather a complete collection of a particular series.", "Comics are assigned sequential numbers, and the initial issue of a long-lasting comic book series tends to be both the scarcest and the most coveted among collectors.", "The introduction of a new character might occur within an existing title.", "For instance, the first appearance of Spider-Man took place in ''Amazing Fantasy'' #15.New characters were frequently introduced in this manner, waiting for an established audience before launching their own titles.", "Consequently, comics featuring the debut appearance of a significant character can sometimes be even more challenging to locate than the inaugural issue of that character's standalone series.Some rare comic books include copies of the unreleased ''Motion Picture Funnies Weekly'' #1 from 1939.Eight copies, plus one without a cover, emerged in the estate of the deceased publisher in 1974.The \"Pay Copy\" of this book sold for $43,125 in a 2005 Heritage auction.The most valuable American comics have combined rarity and quality with the first appearances of popular and enduring characters.", "Four comic books have sold for over US$1 million , including two examples of ''Action Comics'' #1, the first appearance of Superman, both sold privately through online dealer ComicConnect.com in 2010, and ''Detective Comics'' #27, the first appearance of Batman, via public auction.Updating the above price obtained for ''Action Comics'' #1, the first appearance of Superman, the highest sale on record for this book is $3.2 million, for a 9.0 copy.", "Misprints, promotional comic-dealer incentive printings, and issues with exceptionally low distribution tend to possess scarcity value in the comic book market.", "The rarest modern comic books include the original press run of ''The League of Extraordinary Gentlemen'' #5, which DC executive Paul Levitz recalled and pulped due to the appearance of a vintage Victorian era advertisement for \"Marvel Douche\", which the publisher considered offensive; only 100 copies exist, most of which have been CGC graded.", "(See Recalled comics for more pulped, recalled, and erroneous comics.", ")In 2000, a company named Comics Guaranty (CGC) initiated the practice of \"slabbing\" comics, which involves encasing them within thick plastic cases and assigning them a numerical grade.", "This approach inspired the emergence of Comic Book Certification Service.", "Given the significance of condition in determining the value of rare comics, the concept of grading by an impartial company, one that does not engage in buying or selling comics, seemed promising.", "Nevertheless, there is an ongoing debate regarding whether the relatively high cost of this grading service is justified and whether it serves the interests of collectors or mainly caters to speculators seeking rapid profits, akin to trading in stocks or fine art.", "Comic grading has played a role in establishing standards for valuation, which online price guides such as GoCollect and GPAnalysis utilize to provide real-time market value information.Collectors also seek out the original artwork pages from comic books, which are perhaps the most rarefied items in the realm of comic book collecting.", "These pages hold unparalleled scarcity due to the fact that there exists only one unique page of artwork for every page that was printed and published.The creation of these original artwork pages involves a collaborative effort: a writer crafts the story, a pencil artist designs the sequential panels on the page, an ink artist goes over the pencil with pen and ink, a letterer provides the dialogue and narration through hand-lettering, and finally, a colorist adds color as the final touch before the pages are sent to the printer.When the printer returns the original artwork pages, they are typically returned to the artists themselves.", "These artists sometimes opt to sell these pages at comic book conventions, in galleries, and at art shows centered around comic book art.", "The original pages from DC and Marvel, featuring the debut appearances of iconic characters such as Superman, Batman, Wonder Woman, the Flash, Captain Marvel, Spider-Man, the Incredible Hulk, Iron Man, Captain America and the Mighty Thor are regarded as priceless treasures within the comic book world.===History of race in U.S. comic books===Many early iterations of black characters in comics \"became variations on the 'single stereotypical image of Sambo'.\"", "Sambo was closely related to the coon stereotype but had some subtle differences.", "They are both a derogatory way of portraying black characters.", "\"The name itself, an abbreviation of raccoon, is dehumanizing.", "As with Sambo, the coon was portrayed as a lazy, easily frightened, chronically idle, inarticulate, buffoon.\"", "This portrayal \"was of course another attempt to solidify the intellectual inferiority of the black race through popular culture.\"", "However, in the 1940s there was a change in portrayal of black characters.", "\"A cursory glance...might give the impression that situations had improved for African Americans in comics.\"", "In many comics being produced in this time there was a major push for tolerance between races.", "\"These equality minded heroes began to spring to action just as African Americans were being asked to participate in the war effort.", "\"During this time, a government ran program, the Writers' War Board, became heavily involved in what would be published in comics.", "\"The Writers' War Board used comic books to shape popular perceptions of race and ethnicity...\" Not only were they using comic books as a means of recruiting all Americans, they were also using it as propaganda to \"construct a justification for race-based hatred of America's foreign enemies.\"", "The Writers' War Board created comics books that were meant to \"promote domestic racial harmony\".", "However, \"these pro-tolerance narratives struggled to overcome the popular and widely understood negative tropes used for decades in American mass culture...\".", "However, they were not accomplishing this agenda within all of their comics.In the comic series ''Captain Marvel Adventures'', there was a character named Steamboat who embodied a collection of highly negative stereotypes prevalent during that period.", "The Writers' War Board did not request any alterations to this character despite the problematic portrayal.", "The removal of Steamboat from the series only came about due to the persistent advocacy of a black youth group based in New York City.\"", "Originally their request was refused by individuals working on the comic stating, \"''Captain Marvel Adventures'' included many kinds of caricatures 'for the sake of humor'.\"", "The black youth group responded with \"this is not the Negro race, but your one-and-a-half millions readers will think it so.\"", "Afterwards, Steamboat disappeared from the comics all together.", "There was a comic created about the 99th Squadron, also known as the Tuskegee Airmen, an all-black air force unit.", "Instead of making the comic about their story, the comic was about Hop Harrigan.", "A white pilot who captures a Nazi, shows him videos of the 99th Squadron defeating his men and then reveals to the Nazi that his men were defeated by African Americans which infuriated him as he sees them as a less superior race and cannot believe they bested his men.", "\"The Tuskegee Airmen, and images of black aviators appear in just three of the fifty three panels... the pilots of the 99th Squadron have no dialogue and interact with neither Hop Harrigan nor his Nazi captive.\"", "During this time, they also used black characters in comic books as a means to invalidate the militant black groups that were fighting for equality within the U.S. \"Spider-Man 'made it clear that militant black power was not the remedy for racial injustice'.\"", "\"The Falcon openly criticized black behavior stating' maybe it's important us to cool things down-so we can protect the rights we been fightin' for'.\"", "This portrayal and character development of black characters can be partially blamed on the fact that, during this time, \"there had rarely been a black artist or writer allowed in a major comics company.", "\"Asian characters within comic books encountered similar prejudiced treatment as black characters did.", "They were subjected to dehumanizing depictions, with narratives often portraying them as \"incompetent and subhuman.\"", "In a 1944 edition of the publication ''United States Marines'', there was a story titled ''The Smell of the Monkeymen''.", "This narrative portrayed Japanese soldiers as brutish simians, and it depicted their concealed positions being betrayed by their repugnant body odor.", "Chinese characters received the same treatment.", "\"By the time the United States entered WWII, negative perceptions of Chinese were an established part of mass culture....\" However, concerned that the Japanese could use America's anti-Chinese material as propaganda they began \"to present a more positive image of America's Chinese allies...\" Just as they tried to show better representation for Black people in comics they did the same for Asian people.", "However, \"Japanese and Filipino characters were visually indistinguishable.", "Both groups have grotesque buckteeth, tattered clothing, and bright yellow skin.\"", "\"Publishers depicted America's Asian allies through derogatory images and language honed over the preceding decades.\"", "Asian characters were previously portrayed as, \"ghastly yellow demons\".", "During WWII, \"every major superhero worth his spandex devoted himself to the eradication of Asian invaders.\"", "There was \"a constant relay race in which one Asian culture merely handed off the baton of hatred to another with no perceptible changes in the manner in which the characters would be portrayed.", "\"\"The only specific depiction of a Hispanic superhero did not end well.", "In 1975, Marvel gave us Hector Ayala (a.k.a The White Tiger).\"", "\"Although he fought for several years alongside the likes of much more popular heroes such as Spider-Man and Daredevil, he only lasted six years before sales of comics featuring him got so bad that Marvel had him retire.", "The most famous Hispanic character is Bane, a villain from Batman.", "\"The Native American representation in comic books \"can be summed up in the noble savage stereotype\" \" a recurring theme...urged American indians to abandon their traditional hostility towards the United States.", "They were the ones painted as intolerant and disrespectful of the dominant concerns of white America\"." ], [ "East Asian comics", "===Japanese manga===Manga (漫画) are comic books or graphic novels originating from Japan.", "Most manga conform to a style developed in Japan in the late 19th century, though the art form has a long prehistory in earlier Japanese art.", "The term ''manga'' is used in Japan to refer to both comics and cartooning in general .", "Outside Japan, the word is typically used to refer to comics originally published in the country.===Dōjinshi===, fan-made Japanese comics, operate in a far larger market in Japan than the American \"underground comics\" market; the largest dōjinshi fair, Comiket, attracts 500,000 visitors twice a year.===Korean manhwa=== Manhwa (만화) are comic books or graphic novels originating from South Korea.", "The term ''manhwa'' is used in South Korea to refer to both comics and cartooning in general.", "Outside South Korea, the term usually refers to comics originally published in the country.", "Manhwa is greatly influenced by Japanese Manga comics though it differs from manga and manhua with its own distinct features.===Webtoons===Webtoons have become popular in South Korea as a new way to read comics.", "Thanks in part to different censorship rules, color and unique visual effects, and optimization for easier reading on smartphones and computers.", "More manhwa have made the switch from traditional print manhwa to online webtoons thanks to better pay and more freedom than traditional print manhwa.", "The webtoon format has also expanded to other countries outside of Korea like China, Japan, Southeast Asia, and Western countries.", "Major webtoon distributors include Lezhin, Naver, and Kakao.===Chinese manhua======Vietnamese truyện tranh===" ], [ "European comics", "===Franco-Belgian comics===René Goscinny (1926–1977), writer of the ''Astérix'' comic book series.", "France and Belgium have a long tradition in comics and comic books, often called ''BDs'' (an abbreviation of ''bandes dessinées'', meaning literally \"drawn strips\") in French, and ''strips'' in Dutch or Flemish.", "Belgian comic books originally written in Dutch show the influence of the Francophone \"Franco-Belgian\" comics but have their own distinct style.===British comics===Cover to 27 December 1884 edition of ''Ally Sloper's Half Holiday''.", "Ally Sloper is regarded as the first recurring character in comics.Although ''Ally Sloper's Half Holiday'' (1884) was aimed at an adult market, publishers quickly targeted a younger demographic, which has led to most publications being for children and has created an association in the public's mind of comics as somewhat juvenile.", "''The Guardian'' refers to Ally Sloper as \"one of the world's first iconic cartoon characters\", and \"as famous in Victorian Britain as Dennis the Menace would be a century later.\"", "British comics in the early 20th century typically evolved from illustrated penny dreadfuls of the Victorian era (featuring Sweeney Todd, Dick Turpin and ''Varney the Vampire'').", "First published in the 1830s, penny dreadfuls were \"Britain's first taste of mass-produced popular culture for the young.", "\"Statue of Minnie the Minx, a character from ''The Beano'', in Dundee, Scotland.", "Launched in 1938, ''The Beano'' is known for its anarchic humour, with ''Dennis the Menace'' appearing on the cover.The two most popular British comic books, ''The Beano'' and ''The Dandy'', were first published by DC Thomson in the 1930s.", "By 1950 the weekly circulation of both reached two million.", "Explaining the enormous popularity of comics in the UK during this period, Anita O'Brien, director curator at London's Cartoon Museum, states: \"When comics like the Beano and Dandy were invented back in the 1930s – and through really to the 1950s and 60s – these comics were almost the only entertainment available to children.\"", "''Dennis the Menace'' was created in the 1950s, which saw sales for ''The Beano'' soar.", "He features in the cover of ''The Beano'', with the BBC referring to him as the \"definitive naughty boy of the comic world.", "\"In 1954, ''Tiger'' comics introduced ''Roy of the Rovers'', the hugely popular football based strip recounting the life of Roy Race and the team he played for, Melchester Rovers.", "The stock media phrase \"real 'Roy of the Rovers' stuff\" is often used by football writers, commentators and fans when describing displays of great skill, or surprising results that go against the odds, in reference to the dramatic storylines that were the strip's trademark.", "Other comic books such as ''Eagle'', ''Valiant'', ''Warrior'', ''Viz'' and ''2000 AD'' also flourished.", "Some comics, such as ''Judge Dredd'' and other ''2000 AD'' titles, have been published in a tabloid form.", "Underground comics and \"small press\" titles have also appeared in the UK, notably ''Oz'' and ''Escape Magazine''.The content of ''Action'', another title aimed at children and launched in the mid-1970s, became the subject of discussion in the House of Commons.", "Although on a smaller scale than similar investigations in the US, such concerns led to a moderation of content published within British comics.", "Such moderation never became formalized to the extent of promulgating a code, nor did it last long.", "The UK has also established a healthy market in the reprinting and repackaging of material, notably material originating in the US.", "The lack of reliable supplies of American comic books led to a variety of black-and-white reprints, including Marvel's monster comics of the 1950s, Fawcett's Captain Marvel, and other characters such as Sheena, Mandrake the Magician, and the Phantom.", "Several reprint companies became involved in repackaging American material for the British market, notably the importer and distributor Thorpe & Porter.", "Marvel Comics established a UK office in 1972.DC Comics and Dark Horse Comics also opened offices in the 1990s.", "The repackaging of European material has occurred less frequently, although ''The Adventures of Tintin'' and ''Asterix'' serials have been successfully translated and repackaged in softcover books.", "The number of European comics available in the UK has increased in the last two decades.", "The British company Cinebook, founded in 2005, has released English translated versions of many European series.In the 1980s, a resurgence of British writers and artists gained prominence in mainstream comic books, which was dubbed the \"British Invasion\" in comic book history.", "These writers and artists brought with them their own mature themes and philosophy such as anarchy, controversy and politics common in British media.", "These elements would pave the way for mature and \"darker and edgier\" comic books and jump start the Modern Age of Comics.", "Writers included Alan Moore, famous for his ''V for Vendetta'', ''From Hell'', ''Watchmen'', ''Marvelman'', and ''The League of Extraordinary Gentlemen''; Neil Gaiman with ''The Sandman'' mythos and ''Books of Magic''; Warren Ellis, creator of ''Transmetropolitan'' and ''Planetary''; and others such as Mark Millar, creator of ''Wanted'' and ''Kick-Ass''.", "The comic book series ''John Constantine, Hellblazer'', which is largely set in Britain and starring the magician John Constantine, paved the way for British writers such as Jamie Delano.The English musician Peter Gabriel issued in 2000 The Story of OVO which was released in a CD-booklet-shaped comic book as part of the CD edition with the title \"OVO The Millennium Show\".", "The 2000 Millennium Dome Show based on it.At Christmas, publishers repackage and commission material for comic annuals, printed and bound as hardcover A4-size books; \"Rupert\" supplies a famous example of the British comic annual.", "DC Thomson also repackages ''The Broons'' and ''Oor Wullie'' strips in softcover A4-size books for the holiday season.On 19 March 2012, the British postal service, the Royal Mail, released a set of stamps depicting British comic book characters and series.", "The collection featured ''The Beano'', ''The Dandy'', ''Eagle'', ''The Topper'', ''Roy of the Rovers'', ''Bunty'', ''Buster'', ''Valiant'', ''Twinkle'' and ''2000 AD''.===Spanish comics===It has been stated that the 13th century ''Cantigas de Santa María'' could be considered as the first Spanish \"comic\", although comic books (also known in Spain as ''historietas'' or ''tebeos'') made their debut around 1857.The magazine ''TBO'' was influential in popularizing the medium.", "After the Spanish Civil War, the Franco regime imposed strict censorship in all media: superhero comics were forbidden and as a result, comic heroes were based on historical fiction (in 1944 the medieval hero ''El Guerrero del Antifaz'' was created by Manuel Gago and another popular medieval hero, ''Capitán Trueno'', was created in 1956 by Víctor Mora and Miguel Ambrosio Zaragoza).", "Two publishing houses — Editorial Bruguera and Editorial Valenciana — dominated the Spanish comics market during its golden age (1950–1970).", "The most popular comics showed a recognizable style of slapstick humor (influenced by Franco-Belgian authors such as Franquin): Escobar's ''Carpanta'' and ''Zipi y Zape'', Vázquez's ''Las hermanas Gilda'' and ''Anacleto,'' Ibáñez's ''Mortadelo y Filemón'' and ''13.Rue del Percebe'' or Jan's ''Superlópez''.", "After the end of the Francoist period, there was an increased interest in adult comics with magazines such as ''Totem'', ''El Jueves'', ''1984'', and ''El Víbora,'' and works such as ''Paracuellos'' by Carlos Giménez.Spanish artists have traditionally worked in other markets finding great success, either in the American (e.g., Eisner Award winners Sergio Aragonés, Salvador Larroca, Gabriel Hernández Walta, Marcos Martín or David Aja), the British (e.g., Carlos Ezquerra, co-creator of ''Judge Dredd'') or the Franco-Belgian one (e.g., Fauve d'Or winner Julio Ribera or ''Blacksad'' authors Juan Díaz Canales and Juanjo Guarnido).===Italian comics===Hugo Pratt (1927–1995), author of the ''Corto Maltese'' comic book series.In Italy, comics (known in Italian as ''fumetti'') made their debut as humor strips at the end of the 19th century, and later evolved into adventure stories.", "After World War II, however, artists like Hugo Pratt and Guido Crepax exposed Italian comics to an international audience.", "Popular comic books such as ''Diabolik'' or the ''Bonelli'' line—namely ''Tex Willer'' or ''Dylan Dog''—remain best-sellers.Mainstream comics are usually published on a monthly basis, in a black-and-white digest size format, with approximately 100 to 132 pages.", "Collections of classic material for the most famous characters, usually with more than 200 pages, are also common.", "Author comics are published in the French BD format, with an example being Pratt's ''Corto Maltese''.Italian cartoonists show the influence of comics from other countries, including France, Belgium, Spain, and Argentina.", "Italy is also famous for being one of the foremost producers of Walt Disney comic stories outside the US; Donald Duck's superhero alter ego, Paperinik, known in English as Superduck, was created in Italy." ], [ "Comics in other countries" ], [ "Distribution", "The comic book industry has struggled with distribution issues throughout its history, as numerous mainstream retailers have been hesitant to stock substantial quantities of the most engaging and sought-after comics.", "The smartphone and the tablet have turned out to be an ideal medium for online distribution.===Digital distribution===On 13 November 2007, Marvel Comics launched Marvel Digital Comics Unlimited, a subscription service allowing readers to read many comics from Marvel's history online.", "The service also includes periodic release new comics not available elsewhere.", "With the release of ''Avenging Spider-Man'' #1, Marvel also became the first publisher to provide free digital copies as part of the print copy of the comic book.With the growing popularity of smartphones and tablets, many major publishers have begun releasing titles in digital form.", "The most popular platform is comiXology.", "Some platforms, such as Graphicly, have shut down." ], [ "Comic collections in libraries", "Numerous libraries house extensive collections of comics in the form of graphic novels.", "This serves as a convenient means for the general public to become acquainted with the medium." ], [ "Guinness World Records", "In 2015, the Japanese manga artist Eiichiro Oda was awarded the ''Guinness World Records'' title for having the \"Most copies published for the same comic book series by a single author\".", "His manga series ''One Piece'', which he writes and illustrates, has been serialized in the Japanese magazine ''Weekly Shōnen Jump'' since December 1997, and by 2015, 77 collected volumes had been released.", "''Guinness World Records'' reported in their announcement that the collected volumes of the series had sold a total of 320,866,000 units.", "''One Piece'' also holds the ''Guinness World Records'' title for \"Most copies published for the same manga series\".On 5 August 2018, the ''Guinness World Records'' title for the \"Largest comic book ever published\" was awarded to the Brazilian comic book ''Turma da Mônica — O Maior Gibi do Mundo!", "'', published by Panini Comics Brasil and Mauricio de Sousa Produções.", "The comic book measures 69.9 cm by 99.8 cm (2 ft 3.51 in by 3 ft 3.29 in).", "The 18-page comic book had a print run of 120 copies.With the July 2021 publication of the 201st collected volume of his manga series ''Golgo 13'', Japanese manga artist Takao Saito was awarded the ''Guinness World Records'' title for \"Most volumes published for a single manga series.\"", "''Golgo 13'' has been continuously serialized in the Japanese magazine ''Big Comic'' since October 1968, which also makes it the oldest manga still in publication." ], [ "See also", "* Cartoon* Comic book archive* Comic book therapy* Comics studies* Comics vocabulary* Comparison of image viewers* List of best-selling comic series* List of best-selling manga* Webcomic" ], [ "References" ], [ "Further reading", "* * *" ], [ "External links", "* Comic book Speculation Reference* Comic book Reference Bibliographic Datafile* Sequart Research & Literacy Organization* Comic Art Collection at the University of Missouri* Collectorism – a place for collectors and collectibles" ] ]
wikipedia
[ [ "Connected space" ], [ "Introduction", "In topology and related branches of mathematics, a '''connected space''' is a topological space that cannot be represented as the union of two or more disjoint non-empty open subsets.", "Connectedness is one of the principal topological properties that are used to distinguish topological spaces.A subset of a topological space is a '''''' if it is a connected space when viewed as a subspace of .Some related but stronger conditions are path connected, simply connected, and -connected.", "Another related notion is ''locally connected'', which neither implies nor follows from connectedness." ], [ "Formal definition", "A topological space is said to be '''''' if it is the union of two disjoint non-empty open sets.", "Otherwise, is said to be '''connected'''.", "A subset of a topological space is said to be connected if it is connected under its subspace topology.", "Some authors exclude the empty set (with its unique topology) as a connected space, but this article does not follow that practice.For a topological space the following conditions are equivalent:# is connected, that is, it cannot be divided into two disjoint non-empty open sets.#The only subsets of which are both open and closed (clopen sets) are and the empty set.#The only subsets of with empty boundary are and the empty set.# cannot be written as the union of two non-empty separated sets (sets for which each is disjoint from the other's closure).", "#All continuous functions from to are constant, where is the two-point space endowed with the discrete topology.Historically this modern formulation of the notion of connectedness (in terms of no partition of into two separated sets) first appeared (independently) with N.J. Lennes, Frigyes Riesz, and Felix Hausdorff at the beginning of the 20th century.", "See for details.===Connected components===Given some point in a topological space the union of any collection of connected subsets such that each contained will once again be a connected subset.", "The '''connected component of a point''' in is the union of all connected subsets of that contain it is the unique largest (with respect to ) connected subset of that contains The maximal connected subsets (ordered by inclusion ) of a non-empty topological space are called the '''connected components''' of the space.The components of any topological space form a partition of : they are disjoint, non-empty and their union is the whole space.Every component is a closed subset of the original space.", "It follows that, in the case where their number is finite, each component is also an open subset.", "However, if their number is infinite, this might not be the case; for instance, the connected components of the set of the rational numbers are the one-point sets (singletons), which are not open.", "Proof: Any two distinct rational numbers are in different components.", "Take an irrational number and then set and Then is a separation of and .", "Thus each component is a one-point set.Let be the connected component of in a topological space and be the intersection of all clopen sets containing (called quasi-component of ) Then where the equality holds if is compact Hausdorff or locally connected.===Disconnected spaces===A space in which all components are one-point sets is called ''''''.", "Related to this property, a space is called '''''' if, for any two distinct elements and of , there exist disjoint open sets containing and containing such that is the union of and .", "Clearly, any totally separated space is totally disconnected, but the converse does not hold.", "For example take two copies of the rational numbers , and identify them at every point except zero.", "The resulting space, with the quotient topology, is totally disconnected.", "However, by considering the two copies of zero, one sees that the space is not totally separated.", "In fact, it is not even Hausdorff, and the condition of being totally separated is strictly stronger than the condition of being Hausdorff." ], [ "Examples", "* The closed interval in the standard subspace topology is connected; although it can, for example, be written as the union of and the second set is not open in the chosen topology of * The union of and is disconnected; both of these intervals are open in the standard topological space * is disconnected.", "* A convex subset of is connected; it is actually simply connected.", "* A Euclidean plane excluding the origin, is connected, but is not simply connected.", "The three-dimensional Euclidean space without the origin is connected, and even simply connected.", "In contrast, the one-dimensional Euclidean space without the origin is not connected.", "* A Euclidean plane with a straight line removed is not connected since it consists of two half-planes.", "* , the space of real numbers with the usual topology, is connected.", "* The Sorgenfrey line is disconnected.", "* If even a single point is removed from , the remainder is disconnected.", "However, if even a countable infinity of points are removed from , where the remainder is connected.", "If , then remains simply connected after removal of countably many points.", "* Any topological vector space, e.g.", "any Hilbert space or Banach space, over a connected field (such as or ), is simply connected.", "* Every discrete topological space with at least two elements is disconnected, in fact such a space is totally disconnected.", "The simplest example is the discrete two-point space.", "* On the other hand, a finite set might be connected.", "For example, the spectrum of a discrete valuation ring consists of two points and is connected.", "It is an example of a Sierpiński space.", "* The Cantor set is totally disconnected; since the set contains uncountably many points, it has uncountably many components.", "* If a space is homotopy equivalent to a connected space, then is itself connected.", "* The topologist's sine curve is an example of a set that is connected but is neither path connected nor locally connected.", "* The general linear group (that is, the group of -by- real, invertible matrices) consists of two connected components: the one with matrices of positive determinant and the other of negative determinant.", "In particular, it is not connected.", "In contrast, is connected.", "More generally, the set of invertible bounded operators on a complex Hilbert space is connected.", "* The spectra of commutative local ring and integral domains are connected.", "More generally, the following are equivalent*# The spectrum of a commutative ring is connected*# Every finitely generated projective module over has constant rank.", "*# has no idempotent (i.e., is not a product of two rings in a nontrivial way).An example of a space that is not connected is a plane with an infinite line deleted from it.", "Other examples of disconnected spaces (that is, spaces which are not connected) include the plane with an annulus removed, as well as the union of two disjoint closed disks, where all examples of this paragraph bear the subspace topology induced by two-dimensional Euclidean space.== Path connectedness ==This subspace of '''R'''² is path-connected, because a path can be drawn between any two points in the space.A '''''' is a stronger notion of connectedness, requiring the structure of a path.", "A '''path''' from a point to a point in a topological space is a continuous function from the unit interval to with and .", "A '''''' of is an equivalence class of under the equivalence relation which makes equivalent to if there is a path from to .", "The space is said to be '''path-connected''' (or '''pathwise connected''' or '''-connected''') if there is exactly one path-component.", "For non-empty spaces, this is equivalent to the statement that there is a path joining any two points in .", "Again, many authors exclude the empty space.Every path-connected space is connected.", "The converse is not always true: examples of connected spaces that are not path-connected include the extended long line and the topologist's sine curve.Subsets of the real line are connected if and only if they are path-connected; these subsets are the intervals and rays of .Also, open subsets of or are connected if and only if they are path-connected.Additionally, connectedness and path-connectedness are the same for finite topological spaces.== Arc connectedness == A space is said to be '''arc-connected''' or '''arcwise connected''' if any two topologically distinguishable points can be joined by an arc, which is an embedding .", "An '''arc-component''' of is a maximal arc-connected subset of ; or equivalently an equivalence class of the equivalence relation of whether two points can be joined by an arc or by a path whose points are topologically indistinguishable.Every Hausdorff space that is path-connected is also arc-connected; more generally this is true for a -Hausdorff space, which is a space where each image of a path is closed.", "An example of a space which is path-connected but not arc-connected is given by the line with two origins; its two copies of can be connected by a path but not by an arc.Intuition for path-connected spaces does not readily transfer to arc-connected spaces.", "Let be the line with two origins.", "The following are facts whose analogues hold for path-connected spaces, but do not hold for arc-connected spaces:* Continuous image of arc-connected space may not be arc-connected: for example, a quotient map from an arc-connected space to its quotient with countably many (at least 2) topologically distinguishable points cannot be arc-connected due to too small cardinality.", "* Arc-components may not be disjoint.", "For example, has two overlapping arc-components.", "* Arc-connected product space may not be a product of arc-connected spaces.", "For example, is arc-connected, but is not.", "* Arc-components of a product space may not be products of arc-components of the marginal spaces.", "For example, has a single arc-component, but has two arc-components.", "*If arc-connected subsets have a non-empty intersection, then their union may not be arc-connected.", "For example, the arc-components of intersect, but their union is not arc-connected.== Local connectedness ==A topological space is said to be '''locally connected at a point''' if every neighbourhood of contains a connected open neighbourhood.", "It is '''locally connected''' if it has a base of connected sets.", "It can be shown that a space is locally connected if and only if every component of every open set of is open.Similarly, a topological space is said to be '''''' if it has a base of path-connected sets.An open subset of a locally path-connected space is connected if and only if it is path-connected.This generalizes the earlier statement about and , each of which is locally path-connected.", "More generally, any topological manifold is locally path-connected.The topologist's sine curve is connected, but it is not locally connectedLocally connected does not imply connected, nor does locally path-connected imply path connected.", "A simple example of a locally connected (and locally path-connected) space that is not connected (or path-connected) is the union of two separated intervals in , such as .A classical example of a connected space that is not locally connected is the so called topologist's sine curve, defined as , with the Euclidean topology induced by inclusion in ." ], [ "Set operations", "Examples of unions and intersections of connected setsThe '''intersection''' of connected sets is not necessarily connected.The '''union''' of connected sets is not necessarily connected, as can be seen by considering .Each ellipse is a connected set, but the union is not connected, since it can be partitioned to two disjoint open sets and .This means that, if the union is disconnected, then the collection can be partitioned to two sub-collections, such that the unions of the sub-collections are disjoint and open in (see picture).", "This implies that in several cases, a union of connected sets necessarily connected.", "In particular:# If the common intersection of all sets is not empty (), then obviously they cannot be partitioned to collections with disjoint unions.", "Hence the union of connected sets with non-empty intersection is connected.# If the intersection of each pair of sets is not empty () then again they cannot be partitioned to collections with disjoint unions, so their union must be connected.# If the sets can be ordered as a \"linked chain\", i.e.", "indexed by integer indices and , then again their union must be connected.# If the sets are pairwise-disjoint and the quotient space is connected, then must be connected.", "Otherwise, if is a separation of then is a separation of the quotient space (since are disjoint and open in the quotient space).The set difference of connected sets is not necessarily connected.", "However, if and their difference is disconnected (and thus can be written as a union of two open sets and ), then the union of with each such component is connected (i.e.", "is connected for all ).Two connected sets whose difference is not connected" ], [ "Theorems <!--'Main theorem of connectedness' redirects here-->", "*'''Main theorem of connectedness''': Let and be topological spaces and let be a continuous function.", "If is (path-)connected then the image is (path-)connected.", "This result can be considered a generalization of the intermediate value theorem.", "*Every path-connected space is connected.", "*In a locally path-connected space, every open connected set is path-connected.", "*Every locally path-connected space is locally connected.", "*A locally path-connected space is path-connected if and only if it is connected.", "*The closure of a connected subset is connected.", "Furthermore, any subset between a connected subset and its closure is connected.", "*The connected components are always closed (but in general not open)*The connected components of a locally connected space are also open.", "*The connected components of a space are disjoint unions of the path-connected components (which in general are neither open nor closed).", "*Every quotient of a connected (resp.", "locally connected, path-connected, locally path-connected) space is connected (resp.", "locally connected, path-connected, locally path-connected).", "*Every product of a family of connected (resp.", "path-connected) spaces is connected (resp.", "path-connected).", "*Every open subset of a locally connected (resp.", "locally path-connected) space is locally connected (resp.", "locally path-connected).", "*Every manifold is locally path-connected.", "*Arc-wise connected space is path connected, but path-wise connected space may not be arc-wise connected*Continuous image of arc-wise connected set is arc-wise connected." ], [ "Graphs", "Graphs have path connected subsets, namely those subsets for which every pair of points has a path of edges joining them.But it is not always possible to find a topology on the set of points which induces the same connected sets.", "The 5-cycle graph (and any -cycle with odd) is one such example.As a consequence, a notion of connectedness can be formulated independently of the topology on a space.", "To wit, there is a category of connective spaces consisting of sets with collections of connected subsets satisfying connectivity axioms; their morphisms are those functions which map connected sets to connected sets .", "Topological spaces and graphs are special cases of connective spaces; indeed, the finite connective spaces are precisely the finite graphs.However, every graph can be canonically made into a topological space, by treating vertices as points and edges as copies of the unit interval (see topological graph theory#Graphs as topological spaces).", "Then one can show that the graph is connected (in the graph theoretical sense) if and only if it is connected as a topological space." ], [ "Stronger forms of connectedness", "There are stronger forms of connectedness for topological spaces, for instance: * If there exist no two disjoint non-empty open sets in a topological space , must be connected, and thus hyperconnected spaces are also connected.", "* Since a simply connected space is, by definition, also required to be path connected, any simply connected space is also connected.", "If the \"path connectedness\" requirement is dropped from the definition of simple connectivity, a simply connected space does not need to be connected.", "*Yet stronger versions of connectivity include the notion of a contractible space.", "Every contractible space is path connected and thus also connected.In general, any path connected space must be connected but there exist connected spaces that are not path connected.", "The deleted comb space furnishes such an example, as does the above-mentioned topologist's sine curve." ], [ "See also", "* * * * * * * *" ], [ "References" ], [ "Further reading", "* * * * ." ] ]
wikipedia
[ [ "Cell nucleus" ], [ "Introduction", "HeLa cells stained for nuclear DNA with the blue fluorescent Hoechst dye.", "The central and rightmost cells are in interphase, thus their entire nuclei are labeled.", "On the left, a cell is going through mitosis and its DNA has condensed.The '''cell nucleus''' (; : '''nuclei''') is a membrane-bound organelle found in eukaryotic cells.", "Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many.", "The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support.The cell nucleus contains nearly all of the cell's genome.", "Nuclear DNA is often organized into multiple chromosomes – long strands of DNA dotted with various proteins, such as histones, that protect and organize the DNA.", "The genes within these chromosomes are structured in such a way to promote cell function.", "The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expression.Because the nuclear envelope is impermeable to large molecules, nuclear pores are required to regulate nuclear transport of molecules across the envelope.", "The pores cross both nuclear membranes, providing a channel through which larger molecules must be actively transported by carrier proteins while allowing free movement of small molecules and ions.", "Movement of large molecules such as proteins and RNA through the pores is required for both gene expression and the maintenance of chromosomes.", "Although the interior of the nucleus does not contain any membrane-bound subcompartments, a number of nuclear bodies exist, made up of unique proteins, RNA molecules, and particular parts of the chromosomes.", "The best-known of these is the nucleolus, involved in the assembly of ribosomes." ], [ "Structures", "Diagram of the nucleus showing the ribosome-studded outer nuclear membrane, nuclear pores, DNA (complexed as chromatin), and the nucleolus.The nucleus contains nearly all of the cell's DNA, surrounded by a network of fibrous intermediate filaments called the nuclear matrix, and is enveloped in a double membrane called the nuclear envelope.", "The nuclear envelope separates the fluid inside the nucleus, called the nucleoplasm, from the rest of the cell.", "The size of the nucleus is correlated to the size of the cell, and this ratio is reported across a range of cell types and species.", "In eukaryotes the nucleus in many cells typically occupies 10% of the cell volume.", "The nucleus is the largest organelle in animal cells.", "In human cells, the diameter of the nucleus is approximately six micrometres (µm).===Nuclear envelope and pores===A cross section of a nuclear pore on the surface of the nuclear envelope (1).", "Other diagram labels show (2) the outer ring, (3) spokes, (4) basket, and (5) filaments.The nuclear envelope consists of two membranes, an inner and an outer nuclear membrane, perforated by nuclear pores.", "Together, these membranes serve to separate the cell's genetic material from the rest of the cell contents, and allow the nucleus to maintain an environment distinct from the rest of the cell.", "Despite their close apposition around much of the nucleus, the two membranes differ substantially in shape and contents.", "The inner membrane surrounds the nuclear content, providing its defining edge.", "Embedded within the inner membrane, various proteins bind the intermediate filaments that give the nucleus its structure.", "The outer membrane encloses the inner membrane, and is continuous with the adjacent endoplasmic reticulum membrane.", "As part of the endoplasmic reticulum membrane, the outer nuclear membrane is studded with ribosomes that are actively translating proteins across membrane.", "The space between the two membranes is called the perinuclear space, and is continuous with the endoplasmic reticulum lumen.In a mammalian nuclear envelope there are between 3000 and 4000 nuclear pore complexes (NPCs) perforating the envelope.", "Each NPC contains an eightfold-symmetric ring-shaped structure at a position where the inner and outer membranes fuse.", "The number of NPCs can vary considerably across cell types; small glial cells only have about a few hundred, with large Purkinje cells having around 20,000.The NPC provides selective transport of molecules between the nucleoplasm and the cytosol.", "The nuclear pore complex is composed of approximately thirty different proteins known as nucleoporins.", "The pores are about 60–80 million daltons in molecular weight and consist of around 50 (in yeast) to several hundred proteins (in vertebrates).", "The pores are 100 nm in total diameter; however, the gap through which molecules freely diffuse is only about 9 nm wide, due to the presence of regulatory systems within the center of the pore.", "This size selectively allows the passage of small water-soluble molecules while preventing larger molecules, such as nucleic acids and larger proteins, from inappropriately entering or exiting the nucleus.", "These large molecules must be actively transported into the nucleus instead.", "Attached to the ring is a structure called the ''nuclear basket'' that extends into the nucleoplasm, and a series of filamentous extensions that reach into the cytoplasm.", "Both structures serve to mediate binding to nuclear transport proteins.Most proteins, ribosomal subunits, and some RNAs are transported through the pore complexes in a process mediated by a family of transport factors known as karyopherins.", "Those karyopherins that mediate movement into the nucleus are also called importins, whereas those that mediate movement out of the nucleus are called exportins.", "Most karyopherins interact directly with their cargo, although some use adaptor proteins.", "Steroid hormones such as cortisol and aldosterone, as well as other small lipid-soluble molecules involved in intercellular signaling, can diffuse through the cell membrane and into the cytoplasm, where they bind nuclear receptor proteins that are trafficked into the nucleus.", "There they serve as transcription factors when bound to their ligand; in the absence of a ligand, many such receptors function as histone deacetylases that repress gene expression.===Nuclear lamina===In animal cells, two networks of intermediate filaments provide the nucleus with mechanical support: The nuclear lamina forms an organized meshwork on the internal face of the envelope, while less organized support is provided on the cytosolic face of the envelope.", "Both systems provide structural support for the nuclear envelope and anchoring sites for chromosomes and nuclear pores.The nuclear lamina is composed mostly of lamin proteins.", "Like all proteins, lamins are synthesized in the cytoplasm and later transported to the nucleus interior, where they are assembled before being incorporated into the existing network of nuclear lamina.", "Lamins found on the cytosolic face of the membrane, such as emerin and nesprin, bind to the cytoskeleton to provide structural support.", "Lamins are also found inside the nucleoplasm where they form another regular structure, known as the ''nucleoplasmic veil'', that is visible using fluorescence microscopy.", "The actual function of the veil is not clear, although it is excluded from the nucleolus and is present during interphase.", "Lamin structures that make up the veil, such as LEM3, bind chromatin and disrupting their structure inhibits transcription of protein-coding genes.Like the components of other intermediate filaments, the lamin monomer contains an alpha-helical domain used by two monomers to coil around each other, forming a dimer structure called a coiled coil.", "Two of these dimer structures then join side by side, in an antiparallel arrangement, to form a tetramer called a ''protofilament''.", "Eight of these protofilaments form a lateral arrangement that is twisted to form a ropelike ''filament''.", "These filaments can be assembled or disassembled in a dynamic manner, meaning that changes in the length of the filament depend on the competing rates of filament addition and removal.Mutations in lamin genes leading to defects in filament assembly cause a group of rare genetic disorders known as ''laminopathies''.", "The most notable laminopathy is the family of diseases known as progeria, which causes the appearance of premature aging in those with the condition.", "The exact mechanism by which the associated biochemical changes give rise to the aged phenotype is not well understood.===Chromosomes===A mouse fibroblast nucleus in which DNA is stained blue.", "The distinct chromosome territories of chromosome 2 (red) and chromosome 9 (green) are stained with fluorescent in situ hybridization.The cell nucleus contains the majority of the cell's genetic material in the form of multiple linear DNA molecules organized into structures called chromosomes.", "Each human cell contains roughly two meters of DNA.", "During most of the cell cycle these are organized in a DNA-protein complex known as chromatin, and during cell division the chromatin can be seen to form the well-defined chromosomes familiar from a karyotype.", "A small fraction of the cell's genes are located instead in the mitochondria.There are two types of chromatin.", "Euchromatin is the less compact DNA form, and contains genes that are frequently expressed by the cell.", "The other type, heterochromatin, is the more compact form, and contains DNA that is infrequently transcribed.", "This structure is further categorized into ''facultative'' heterochromatin, consisting of genes that are organized as heterochromatin only in certain cell types or at certain stages of development, and ''constitutive'' heterochromatin that consists of chromosome structural components such as telomeres and centromeres.", "During interphase the chromatin organizes itself into discrete individual patches, called ''chromosome territories''.", "Active genes, which are generally found in the euchromatic region of the chromosome, tend to be located towards the chromosome's territory boundary.Antibodies to certain types of chromatin organization, in particular, nucleosomes, have been associated with a number of autoimmune diseases, such as systemic lupus erythematosus.", "These are known as anti-nuclear antibodies (ANA) and have also been observed in concert with multiple sclerosis as part of general immune system dysfunction.===Nucleolus===An electron micrograph of a cell nucleus, showing the darkly stained nucleolusThe nucleolus is the largest of the discrete densely stained, membraneless structures known as nuclear bodies found in the nucleus.", "It forms around tandem repeats of rDNA, DNA coding for ribosomal RNA (rRNA).", "These regions are called nucleolar organizer regions (NOR).", "The main roles of the nucleolus are to synthesize rRNA and assemble ribosomes.", "The structural cohesion of the nucleolus depends on its activity, as ribosomal assembly in the nucleolus results in the transient association of nucleolar components, facilitating further ribosomal assembly, and hence further association.", "This model is supported by observations that inactivation of rDNA results in intermingling of nucleolar structures.In the first step of ribosome assembly, a protein called RNA polymerase I transcribes rDNA, which forms a large pre-rRNA precursor.", "This is cleaved into two large rRNA subunits – 5.8S, and 28S, and a small rRNA subunit 18S.", "The transcription, post-transcriptional processing, and assembly of rRNA occurs in the nucleolus, aided by small nucleolar RNA (snoRNA) molecules, some of which are derived from spliced introns from messenger RNAs encoding genes related to ribosomal function.", "The assembled ribosomal subunits are the largest structures passed through the nuclear pores.When observed under the electron microscope, the nucleolus can be seen to consist of three distinguishable regions: the innermost ''fibrillar centers'' (FCs), surrounded by the ''dense fibrillar component'' (DFC) (that contains fibrillarin and nucleolin), which in turn is bordered by the ''granular component'' (GC) (that contains the protein nucleophosmin).", "Transcription of the rDNA occurs either in the FC or at the FC-DFC boundary, and, therefore, when rDNA transcription in the cell is increased, more FCs are detected.", "Most of the cleavage and modification of rRNAs occurs in the DFC, while the latter steps involving protein assembly onto the ribosomal subunits occur in the GC.===Other nuclear bodies===+ '''Subnuclear structure sizes''''''Structure name''''''Structure diameter''' Cajal bodies 0.2–2.0 µm Clastosomes 0.2-0.5 µm PIKA 5 µm PML bodies 0.2–1.0 µm Paraspeckles 0.5–1.0 µm Speckles 20–25 nm Besides the nucleolus, the nucleus contains a number of other nuclear bodies.", "These include Cajal bodies, gemini of Cajal bodies, polymorphic interphase karyosomal association (PIKA), promyelocytic leukaemia (PML) bodies, paraspeckles, and splicing speckles.", "Although little is known about a number of these domains, they are significant in that they show that the nucleoplasm is not a uniform mixture, but rather contains organized functional subdomains.Other subnuclear structures appear as part of abnormal disease processes.", "For example, the presence of small intranuclear rods has been reported in some cases of nemaline myopathy.", "This condition typically results from mutations in actin, and the rods themselves consist of mutant actin as well as other cytoskeletal proteins.====Cajal bodies and gems====A nucleus typically contains between one and ten compact structures called Cajal bodies or coiled bodies (CB), whose diameter measures between 0.2 µm and 2.0 µm depending on the cell type and species.", "When seen under an electron microscope, they resemble balls of tangled thread and are dense foci of distribution for the protein coilin.", "CBs are involved in a number of different roles relating to RNA processing, specifically small nucleolar RNA (snoRNA) and small nuclear RNA (snRNA) maturation, and histone mRNA modification.Similar to Cajal bodies are Gemini of Cajal bodies, or gems, whose name is derived from the Gemini constellation in reference to their close \"twin\" relationship with CBs.", "Gems are similar in size and shape to CBs, and in fact are virtually indistinguishable under the microscope.", "Unlike CBs, gems do not contain small nuclear ribonucleoproteins (snRNPs), but do contain a protein called survival of motor neuron (SMN) whose function relates to snRNP biogenesis.", "Gems are believed to assist CBs in snRNP biogenesis, though it has also been suggested from microscopy evidence that CBs and gems are different manifestations of the same structure.", "Later ultrastructural studies have shown gems to be twins of Cajal bodies with the difference being in the coilin component; Cajal bodies are SMN positive and coilin positive, and gems are SMN positive and coilin negative.====PIKA and PTF domains====PIKA domains, or polymorphic interphase karyosomal associations, were first described in microscopy studies in 1991.Their function remains unclear, though they were not thought to be associated with active DNA replication, transcription, or RNA processing.", "They have been found to often associate with discrete domains defined by dense localization of the transcription factor PTF, which promotes transcription of small nuclear RNA (snRNA).====PML-nuclear bodies====Promyelocytic leukemia protein (PML-nuclear bodies) are spherical bodies found scattered throughout the nucleoplasm, measuring around 0.1–1.0 µm.", "They are known by a number of other names, including nuclear domain 10 (ND10), Kremer bodies, and PML oncogenic domains.", "PML-nuclear bodies are named after one of their major components, the promyelocytic leukemia protein (PML).", "They are often seen in the nucleus in association with Cajal bodies and cleavage bodies.", "Pml-/- mice, which are unable to create PML-nuclear bodies, develop normally without obvious ill effects, showing that PML-nuclear bodies are not required for most essential biological processes.==== Splicing speckles====Speckles are subnuclear structures that are enriched in pre-messenger RNA splicing factors and are located in the interchromatin regions of the nucleoplasm of mammalian cells.At the fluorescence-microscope level they appear as irregular, punctate structures, which vary in size and shape, and when examined by electron microscopy they are seen as clusters of interchromatin granules.", "Speckles are dynamic structures, and both their protein and RNA-protein components can cycle continuously between speckles and other nuclear locations, including active transcription sites.", "Speckles can work with p53 as enhancers of gene activity to directly enhance the activity of certain genes.", "Moreover, speckle-associating and non-associating p53 gene targets are functionally distinct.Studies on the composition, structure and behaviour of speckles have provided a model for understanding the functional compartmentalization of the nucleus and the organization of the gene-expression machinery splicing snRNPs and other splicing proteins necessary for pre-mRNA processing.", "Because of a cell's changing requirements, the composition and location of these bodies changes according to mRNA transcription and regulation via phosphorylation of specific proteins.", "The splicing speckles are also known as nuclear speckles (nuclear specks), splicing factor compartments (SF compartments), interchromatin granule clusters (IGCs), and B snurposomes.B snurposomes are found in the amphibian oocyte nuclei and in ''Drosophila melanogaster'' embryos.", "B snurposomes appear alone or attached to the Cajal bodies in the electron micrographs of the amphibian nuclei.", "IGCs function as storage sites for the splicing factors.====Paraspeckles====Discovered by Fox et al.", "in 2002, paraspeckles are irregularly shaped compartments in the interchromatin space of the nucleus.", "First documented in HeLa cells, where there are generally 10–30 per nucleus, paraspeckles are now known to also exist in all human primary cells, transformed cell lines, and tissue sections.", "Their name is derived from their distribution in the nucleus; the \"para\" is short for parallel and the \"speckles\" refers to the splicing speckles to which they are always in close proximity.Paraspeckles sequester nuclear proteins and RNA and thus appear to function as a molecular sponge that is involved in the regulation of gene expression.", "Furthermore, paraspeckles are dynamic structures that are altered in response to changes in cellular metabolic activity.", "They are transcription dependent and in the absence of RNA Pol II transcription, the paraspeckle disappears and all of its associated protein components (PSP1, p54nrb, PSP2, CFI(m)68, and PSF) form a crescent shaped perinucleolar cap in the nucleolus.", "This phenomenon is demonstrated during the cell cycle.", "In the cell cycle, paraspeckles are present during interphase and during all of mitosis except for telophase.", "During telophase, when the two daughter nuclei are formed, there is no RNA Pol II transcription so the protein components instead form a perinucleolar cap.==== Perichromatin fibrils====Perichromatin fibrils are visible only under electron microscope.", "They are located next to the transcriptionally active chromatin and are hypothesized to be the sites of active pre-mRNA processing.====Clastosomes====Clastosomes are small nuclear bodies (0.2–0.5 µm) described as having a thick ring-shape due to the peripheral capsule around these bodies.", "This name is derived from the Greek ''klastos'', broken and ''soma'', body.", "Clastosomes are not typically present in normal cells, making them hard to detect.", "They form under high proteolytic conditions within the nucleus and degrade once there is a decrease in activity or if cells are treated with proteasome inhibitors.", "The scarcity of clastosomes in cells indicates that they are not required for proteasome function.", "Osmotic stress has also been shown to cause the formation of clastosomes.", "These nuclear bodies contain catalytic and regulatory subunits of the proteasome and its substrates, indicating that clastosomes are sites for degrading proteins." ], [ "Function", "The nucleus provides a site for genetic transcription that is segregated from the location of translation in the cytoplasm, allowing levels of gene regulation that are not available to prokaryotes.", "The main function of the cell nucleus is to control gene expression and mediate the replication of DNA during the cell cycle.===Cell compartmentalization===The nuclear envelope allows control of the nuclear contents, and separates them from the rest of the cytoplasm where necessary.", "This is important for controlling processes on either side of the nuclear membrane: In most cases where a cytoplasmic process needs to be restricted, a key participant is removed to the nucleus, where it interacts with transcription factors to downregulate the production of certain enzymes in the pathway.", "This regulatory mechanism occurs in the case of glycolysis, a cellular pathway for breaking down glucose to produce energy.", "Hexokinase is an enzyme responsible for the first the step of glycolysis, forming glucose-6-phosphate from glucose.", "At high concentrations of fructose-6-phosphate, a molecule made later from glucose-6-phosphate, a regulator protein removes hexokinase to the nucleus, where it forms a transcriptional repressor complex with nuclear proteins to reduce the expression of genes involved in glycolysis.In order to control which genes are being transcribed, the cell separates some transcription factor proteins responsible for regulating gene expression from physical access to the DNA until they are activated by other signaling pathways.", "This prevents even low levels of inappropriate gene expression.", "For example, in the case of NF-κB-controlled genes, which are involved in most inflammatory responses, transcription is induced in response to a signal pathway such as that initiated by the signaling molecule TNF-α, binds to a cell membrane receptor, resulting in the recruitment of signalling proteins, and eventually activating the transcription factor NF-κB.", "A nuclear localisation signal on the NF-κB protein allows it to be transported through the nuclear pore and into the nucleus, where it stimulates the transcription of the target genes.The compartmentalization allows the cell to prevent translation of unspliced mRNA.", "Eukaryotic mRNA contains introns that must be removed before being translated to produce functional proteins.", "The splicing is done inside the nucleus before the mRNA can be accessed by ribosomes for translation.", "Without the nucleus, ribosomes would translate newly transcribed (unprocessed) mRNA, resulting in malformed and nonfunctional proteins.===Replication===The main function of the cell nucleus is to control gene expression and mediate the replication of DNA during the cell cycle.", "It has been found that replication happens in a localised way in the cell nucleus.", "In the S phase of interphase of the cell cycle; replication takes place.", "Contrary to the traditional view of moving replication forks along stagnant DNA, a concept of ''replication factories'' emerged, which means replication forks are concentrated towards some immobilised 'factory' regions through which the template DNA strands pass like conveyor belts.===Gene expression===transcription factory during transcription, highlighting the possibility of transcribing more than one gene at a time.", "The diagram includes 8 RNA polymerases however the number can vary depending on cell type.", "The image also includes transcription factors and a porous, protein core.Gene expression first involves transcription, in which DNA is used as a template to produce RNA.", "In the case of genes encoding proteins, that RNA produced from this process is messenger RNA (mRNA), which then needs to be translated by ribosomes to form a protein.", "As ribosomes are located outside the nucleus, mRNA produced needs to be exported.Since the nucleus is the site of transcription, it also contains a variety of proteins that either directly mediate transcription or are involved in regulating the process.", "These proteins include helicases, which unwind the double-stranded DNA molecule to facilitate access to it, RNA polymerases, which bind to the DNA promoter to synthesize the growing RNA molecule, topoisomerases, which change the amount of supercoiling in DNA, helping it wind and unwind, as well as a large variety of transcription factors that regulate expression.===Processing of pre-mRNA===Newly synthesized mRNA molecules are known as primary transcripts or pre-mRNA.", "They must undergo post-transcriptional modification in the nucleus before being exported to the cytoplasm; mRNA that appears in the cytoplasm without these modifications is degraded rather than used for protein translation.", "The three main modifications are 5' capping, 3' polyadenylation, and RNA splicing.", "While in the nucleus, pre-mRNA is associated with a variety of proteins in complexes known as heterogeneous ribonucleoprotein particles (hnRNPs).", "Addition of the 5' cap occurs co-transcriptionally and is the first step in post-transcriptional modification.", "The 3' poly-adenine tail is only added after transcription is complete.RNA splicing, carried out by a complex called the spliceosome, is the process by which introns, or regions of DNA that do not code for protein, are removed from the pre-mRNA and the remaining exons connected to re-form a single continuous molecule.", "This process normally occurs after 5' capping and 3' polyadenylation but can begin before synthesis is complete in transcripts with many exons.", "Many pre-mRNAs can be spliced in multiple ways to produce different mature mRNAs that encode different protein sequences.", "This process is known as alternative splicing, and allows production of a large variety of proteins from a limited amount of DNA." ], [ "Dynamics and regulation", "===Nuclear transport===Macromolecules, such as RNA and proteins, are actively transported across the nuclear membrane in a process called the Ran-GTP nuclear transport cycle.The entry and exit of large molecules from the nucleus is tightly controlled by the nuclear pore complexes.", "Although small molecules can enter the nucleus without regulation, macromolecules such as RNA and proteins require association karyopherins called importins to enter the nucleus and exportins to exit.", "\"Cargo\" proteins that must be translocated from the cytoplasm to the nucleus contain short amino acid sequences known as nuclear localization signals, which are bound by importins, while those transported from the nucleus to the cytoplasm carry nuclear export signals bound by exportins.", "The ability of importins and exportins to transport their cargo is regulated by GTPases, enzymes that hydrolyze the molecule guanosine triphosphate (GTP) to release energy.", "The key GTPase in nuclear transport is Ran, which is bound to either GTP or GDP (guanosine diphosphate), depending on whether it is located in the nucleus or the cytoplasm.", "Whereas importins depend on RanGTP to dissociate from their cargo, exportins require RanGTP in order to bind to their cargo.Nuclear import depends on the importin binding its cargo in the cytoplasm and carrying it through the nuclear pore into the nucleus.", "Inside the nucleus, RanGTP acts to separate the cargo from the importin, allowing the importin to exit the nucleus and be reused.", "Nuclear export is similar, as the exportin binds the cargo inside the nucleus in a process facilitated by RanGTP, exits through the nuclear pore, and separates from its cargo in the cytoplasm.Specialized export proteins exist for translocation of mature mRNA and tRNA to the cytoplasm after post-transcriptional modification is complete.", "This quality-control mechanism is important due to these molecules' central role in protein translation.", "Mis-expression of a protein due to incomplete excision of exons or mis-incorporation of amino acids could have negative consequences for the cell; thus, incompletely modified RNA that reaches the cytoplasm is degraded rather than used in translation.===Assembly and disassembly===An image of a newt lung cell stained with fluorescent dyes during metaphase.", "The mitotic spindle can be seen, stained green, attached to the two sets of chromosomes, stained light blue.", "All chromosomes but one are already at the metaphase plate.", "During its lifetime, a nucleus may be broken down or destroyed, either in the process of cell division or as a consequence of apoptosis (the process of programmed cell death).", "During these events, the structural components of the nucleus — the envelope and lamina — can be systematically degraded.In most cells, the disassembly of the nuclear envelope marks the end of the prophase of mitosis.", "However, this disassembly of the nucleus is not a universal feature of mitosis and does not occur in all cells.", "Some unicellular eukaryotes (e.g., yeasts) undergo so-called closed mitosis, in which the nuclear envelope remains intact.", "In closed mitosis, the daughter chromosomes migrate to opposite poles of the nucleus, which then divides in two.", "The cells of higher eukaryotes, however, usually undergo open mitosis, which is characterized by breakdown of the nuclear envelope.", "The daughter chromosomes then migrate to opposite poles of the mitotic spindle, and new nuclei reassemble around them.At a certain point during the cell cycle in open mitosis, the cell divides to form two cells.", "In order for this process to be possible, each of the new daughter cells must have a full set of genes, a process requiring replication of the chromosomes as well as segregation of the separate sets.", "This occurs by the replicated chromosomes, the sister chromatids, attaching to microtubules, which in turn are attached to different centrosomes.", "The sister chromatids can then be pulled to separate locations in the cell.", "In many cells, the centrosome is located in the cytoplasm, outside the nucleus; the microtubules would be unable to attach to the chromatids in the presence of the nuclear envelope.", "Therefore, the early stages in the cell cycle, beginning in prophase and until around prometaphase, the nuclear membrane is dismantled.", "Likewise, during the same period, the nuclear lamina is also disassembled, a process regulated by phosphorylation of the lamins by protein kinases such as the CDC2 protein kinase.", "Towards the end of the cell cycle, the nuclear membrane is reformed, and around the same time, the nuclear lamina are reassembled by dephosphorylating the lamins.However, in dinoflagellates, the nuclear envelope remains intact, the centrosomes are located in the cytoplasm, and the microtubules come in contact with chromosomes, whose centromeric regions are incorporated into the nuclear envelope (the so-called closed mitosis with extranuclear spindle).", "In many other protists (e.g., ciliates, sporozoans) and fungi, the centrosomes are intranuclear, and their nuclear envelope also does not disassemble during cell division.Apoptosis is a controlled process in which the cell's structural components are destroyed, resulting in death of the cell.", "Changes associated with apoptosis directly affect the nucleus and its contents, for example, in the condensation of chromatin and the disintegration of the nuclear envelope and lamina.", "The destruction of the lamin networks is controlled by specialized apoptotic proteases called caspases, which cleave the lamin proteins and, thus, degrade the nucleus' structural integrity.", "Lamin cleavage is sometimes used as a laboratory indicator of caspase activity in assays for early apoptotic activity.", "Cells that express mutant caspase-resistant lamins are deficient in nuclear changes related to apoptosis, suggesting that lamins play a role in initiating the events that lead to apoptotic degradation of the nucleus.", "Inhibition of lamin assembly itself is an inducer of apoptosis.The nuclear envelope acts as a barrier that prevents both DNA and RNA viruses from entering the nucleus.", "Some viruses require access to proteins inside the nucleus in order to replicate and/or assemble.", "DNA viruses, such as herpesvirus replicate and assemble in the cell nucleus, and exit by budding through the inner nuclear membrane.", "This process is accompanied by disassembly of the lamina on the nuclear face of the inner membrane.===Disease-related dynamics===Initially, it has been suspected that immunoglobulins in general and autoantibodies in particular do not enter the nucleus.", "Now there is a body of evidence that under pathological conditions (e.g.", "lupus erythematosus) IgG can enter the nucleus." ], [ "Nuclei per cell", "Most eukaryotic cell types usually have a single nucleus, but some have no nuclei, while others have several.", "This can result from normal development, as in the maturation of mammalian red blood cells, or from faulty cell division.===Anucleated cells===Human red blood cells, like those of other mammals, lack nuclei.", "This occurs as a normal part of the cells' development.An anucleated cell contains no nucleus and is, therefore, incapable of dividing to produce daughter cells.", "The best-known anucleated cell is the mammalian red blood cell, or erythrocyte, which also lacks other organelles such as mitochondria, and serves primarily as a transport vessel to ferry oxygen from the lungs to the body's tissues.", "Erythrocytes mature through erythropoiesis in the bone marrow, where they lose their nuclei, organelles, and ribosomes.", "The nucleus is expelled during the process of differentiation from an erythroblast to a reticulocyte, which is the immediate precursor of the mature erythrocyte.", "The presence of mutagens may induce the release of some immature \"micronucleated\" erythrocytes into the bloodstream.", "Anucleated cells can also arise from flawed cell division in which one daughter lacks a nucleus and the other has two nuclei.In flowering plants, this condition occurs in sieve tube elements.===Multinucleated cells===Multinucleated cells contain multiple nuclei.", "Most acantharean species of protozoa and some fungi in mycorrhizae have naturally multinucleated cells.", "Other examples include the intestinal parasites in the genus ''Giardia'', which have two nuclei per cell.", "Ciliates have two kinds of nuclei in a single cell, a somatic macronucleus and a germline micronucleus.", "In humans, skeletal muscle cells, also called myocytes and syncytium, become multinucleated during development; the resulting arrangement of nuclei near the periphery of the cells allows maximal intracellular space for myofibrils.", "Other multinucleate cells in the human are osteoclasts a type of bone cell.", "Multinucleated and binucleated cells can also be abnormal in humans; for example, cells arising from the fusion of monocytes and macrophages, known as giant multinucleated cells, sometimes accompany inflammation and are also implicated in tumor formation.A number of dinoflagellates are known to have two nuclei.", "Unlike other multinucleated cells these nuclei contain two distinct lineages of DNA: one from the dinoflagellate and the other from a symbiotic diatom." ], [ "Evolution", "As the major defining characteristic of the eukaryotic cell, the nucleus's evolutionary origin has been the subject of much speculation.", "Four major hypotheses have been proposed to explain the existence of the nucleus, although none have yet earned widespread support.The first model known as the \"syntrophic model\" proposes that a symbiotic relationship between the archaea and bacteria created the nucleus-containing eukaryotic cell.", "(Organisms of the Archaea and Bacteria domain have no cell nucleus.)", "It is hypothesized that the symbiosis originated when ancient archaea, similar to modern methanogenic archaea, invaded and lived within bacteria similar to modern myxobacteria, eventually forming the early nucleus.", "This theory is analogous to the accepted theory for the origin of eukaryotic mitochondria and chloroplasts, which are thought to have developed from a similar endosymbiotic relationship between proto-eukaryotes and aerobic bacteria.", "One possibility is that the nuclear membrane arose as a new membrane system following the origin of mitochondria in an archaebacterial host.", "The nuclear membrane may have served to protect the genome from damaging reactive oxygen species produced by the protomitochondria.", "The archaeal origin of the nucleus is supported by observations that archaea and eukarya have similar genes for certain proteins, including histones.", "Observations that myxobacteria are motile, can form multicellular complexes, and possess kinases and G proteins similar to eukarya, support a bacterial origin for the eukaryotic cell.A second model proposes that proto-eukaryotic cells evolved from bacteria without an endosymbiotic stage.", "This model is based on the existence of modern Planctomycetota bacteria that possess a nuclear structure with primitive pores and other compartmentalized membrane structures.", "A similar proposal states that a eukaryote-like cell, the chronocyte, evolved first and phagocytosed archaea and bacteria to generate the nucleus and the eukaryotic cell.The most controversial model, known as ''viral eukaryogenesis'', posits that the membrane-bound nucleus, along with other eukaryotic features, originated from the infection of a prokaryote by a virus.", "The suggestion is based on similarities between eukaryotes and viruses such as linear DNA strands, mRNA capping, and tight binding to proteins (analogizing histones to viral envelopes).", "One version of the proposal suggests that the nucleus evolved in concert with phagocytosis to form an early cellular \"predator\".", "Another variant proposes that eukaryotes originated from early archaea infected by poxviruses, on the basis of observed similarity between the DNA polymerases in modern poxviruses and eukaryotes.", "It has been suggested that the unresolved question of the evolution of sex could be related to the viral eukaryogenesis hypothesis.A more recent proposal, the ''exomembrane hypothesis'', suggests that the nucleus instead originated from a single ancestral cell that evolved a second exterior cell membrane; the interior membrane enclosing the original cell then became the nuclear membrane and evolved increasingly elaborate pore structures for passage of internally synthesized cellular components such as ribosomal subunits." ], [ "History<!--'Cytoblast' redirects here-->", "Oldest known depiction of cells and their nuclei by Antonie van Leeuwenhoek, 1719Drawing of a ''Chironomus'' salivary gland cell published by Walther Flemming in 1882.The nucleus contains polytene chromosomes.The nucleus was the first organelle to be discovered.", "What is most likely the oldest preserved drawing dates back to the early microscopist Antonie van Leeuwenhoek (1632–1723).", "He observed a \"lumen\", the nucleus, in the red blood cells of salmon.", "Unlike mammalian red blood cells, those of other vertebrates still contain nuclei.The nucleus was also described by Franz Bauer in 1804 and in more detail in 1831 by Scottish botanist Robert Brown in a talk at the Linnean Society of London.", "Brown was studying orchids under the microscope when he observed an opaque area, which he called the \"areola\" or \"nucleus\", in the cells of the flower's outer layer.", "He did not suggest a potential function.In 1838, Matthias Schleiden proposed that the nucleus plays a role in generating cells, thus he introduced the name \"'''cytoblast'''\" (\"cell builder\").", "He believed that he had observed new cells assembling around \"cytoblasts\".", "Franz Meyen was a strong opponent of this view, having already described cells multiplying by division and believing that many cells would have no nuclei.", "The idea that cells can be generated de novo, by the \"cytoblast\" or otherwise, contradicted work by Robert Remak (1852) and Rudolf Virchow (1855) who decisively propagated the new paradigm that cells are generated solely by cells (\"\").", "The function of the nucleus remained unclear.Between 1877 and 1878, Oscar Hertwig published several studies on the fertilization of sea urchin eggs, showing that the nucleus of the sperm enters the oocyte and fuses with its nucleus.", "This was the first time it was suggested that an individual develops from a (single) nucleated cell.", "This was in contradiction to Ernst Haeckel's theory that the complete phylogeny of a species would be repeated during embryonic development, including generation of the first nucleated cell from a \"monerula\", a structureless mass of primordial protoplasm (\"Urschleim\").", "Therefore, the necessity of the sperm nucleus for fertilization was discussed for quite some time.", "However, Hertwig confirmed his observation in other animal groups, including amphibians and molluscs.", "Eduard Strasburger produced the same results for plants in 1884.This paved the way to assign the nucleus an important role in heredity.", "In 1873, August Weismann postulated the equivalence of the maternal and paternal germ ''cells'' for heredity.", "The function of the nucleus as carrier of genetic information became clear only later, after mitosis was discovered and the Mendelian rules were rediscovered at the beginning of the 20th century; the chromosome theory of heredity was therefore developed." ], [ "See also", "* Nucleus (neuroanatomy)* Nucleoid* Nucleomorph" ], [ "References" ], [ "Further reading", "* :A review article about nuclear lamins, explaining their structure and various roles* :A review article about nuclear transport, explains the principles of the mechanism, and the various transport pathways* :A review article about the nucleus, explaining the structure of chromosomes within the organelle, and describing the nucleolus and other subnuclear bodies* :A review article about the evolution of the nucleus, explaining a number of different theories* :A university level textbook focusing on cell biology.", "Contains information on nucleus structure and function, including nuclear transport, and subnuclear domains" ], [ "External links", "* * Website covering structure and function of the nucleus from the Department of Oncology at the University of Alberta.", "* Information on nuclear components.", "* contains peer-reviewed still images and video clips that illustrate the nucleus.", "* contains digitized commentaries and links to seminal research papers on the nucleus.", "Published online in the Image & Video Library of The American Society for Cell Biology*" ] ]
wikipedia
[ [ "Christmas" ], [ "Introduction", "'''Christmas''' is an annual festival commemorating the birth of Jesus Christ, observed primarily on December 25 as a religious and cultural celebration among billions of people around the world.", "A feast central to the liturgical year in Christianity, it follows the season of Advent (which begins four Sundays before) or the Nativity Fast, and initiates the season of Christmastide, which historically in the West lasts twelve days and culminates on Twelfth Night.", "Christmas Day is a public holiday in many countries, is celebrated religiously by a majority of Christians, as well as culturally by many non-Christians, and forms an integral part of the holiday season surrounding it.The traditional Christmas narrative recounted in the New Testament, known as the Nativity of Jesus, says that Jesus was born in Bethlehem, in accordance with messianic prophecies.", "When Joseph and Mary arrived in the city, the inn had no room, and so they were offered a stable where the Christ Child was soon born, with angels proclaiming this news to shepherds, who then spread the word.There are different hypotheses regarding the date of Jesus's birth, and in the early fourth century, the church fixed the date as December 25.This corresponds to the traditional date of the winter solstice on the Roman calendar.", "It is exactly nine months after Annunciation on March 25, also the date of the spring equinox.", "Most Christians celebrate on December 25 in the Gregorian calendar, which has been adopted almost universally in the civil calendars used in countries throughout the world.", "However, part of the Eastern Christian Churches celebrate Christmas on December 25 of the older Julian calendar, which currently corresponds to January 7 in the Gregorian calendar.", "For Christians, believing that God came into the world in the form of man to atone for the sins of humanity rather than knowing Jesus's exact birth date is considered to be the primary purpose of celebrating Christmas.The customs associated with Christmas in various countries have a mix of pre-Christian, Christian, and secular themes and origins.", "Popular holiday traditions include gift giving; completing an Advent calendar or Advent wreath; Christmas music and caroling; watching Christmas movies; viewing a Nativity play; an exchange of Christmas cards; attending church services; a special meal; and displaying various Christmas decorations, including Christmas trees, Christmas lights, nativity scenes, garlands, wreaths, mistletoe, and holly.", "Additionally, several related and often interchangeable figures, known as Santa Claus, Father Christmas, Saint Nicholas, and Christkind, are associated with bringing gifts to children during the Christmas season and have their own body of traditions and lore.", "Because gift-giving and many other aspects of the Christmas festival involve heightened economic activity, the holiday has become a significant event and a key sales period for retailers and businesses.", "Over the past few centuries, Christmas has had a steadily growing economic effect in many regions of the world." ], [ "Etymology", "The English word ''Christmas'' is a shortened form of 'Christ's Mass'.", "The word is recorded as in 1038 and in 1131.", "(genitive ) is from the Greek (, 'Christ'), a translation of the Hebrew (, 'Messiah'), meaning 'anointed'; and is from the Latin , the celebration of the Eucharist.The form ''Christenmas'' was also used during some periods, but is now considered archaic and dialectal.", "The term derives from Middle English , meaning 'Christian mass'.", "''Xmas'' is an abbreviation of ''Christmas'' found particularly in print, based on the initial letter chi (Χ) in the Greek , although some style guides discourage its use.", "This abbreviation has precedent in Middle English (where is another abbreviation of the Greek word).=== Other names ===The holiday has had various other English names throughout its history.", "The Anglo-Saxons referred to the feast as \"midwinter\", or, more rarely, as (from the Latin below).", "''Nativity'', meaning 'birth', is from the Latin .", "In Old English, ('Yule') referred to the period corresponding to December and January, which was eventually equated with Christian Christmas.", "'Noel' (also 'Nowel' or 'Nowell', as in \"The First Nowell\") entered English in the late 14th century and is from the Old French or , itself ultimately from the Latin meaning 'birth (day)'.", "''Koleda'' is the traditional Slavic name for Christmas and the period from Christmas to Epiphany or, more generally, to Slavic Christmas-related rituals, some dating to pre-Christian times." ], [ "Nativity", "''Adoration of the Shepherds'' (1622) by Gerard van Honthorst depicts the nativity of JesusThe gospels of Luke and Matthew describe Jesus as being born in Bethlehem to the Virgin Mary.", "In the Gospel of Luke, Joseph and Mary travel from Nazareth to Bethlehem in order to be counted for a census, and Jesus is born there and placed in a manger.", "Angels proclaim him a savior for all people, and three shepherds come to adore him.", "In the Gospel of Matthew, by contrast, three magi follow a star to Bethlehem to bring gifts to Jesus, born the king of the Jews.", "King Herod orders the massacre of all the boys less than two years old in Bethlehem, but the family flees to Egypt and later returns to Nazareth." ], [ "History", "=== Early and medieval era ===''Nativity of Christ'', medieval illustration from the of Herrad of Landsberg (12th century)In the 2nd century, the \"earliest church records\" indicate that \"Christians were remembering and celebrating the birth of the Lord\", an \"observance that sprang up organically from the authentic devotion of ordinary believers\"; although \"they did not agree upon a set date\".", "The earliest evidence of Christ's birth being marked on December 25 is a sentence in the ''Chronograph of 354''.", "(a) Liturgical historians generally agree that this part of the text was written in Rome in AD 336.Though Christmas did not appear on the lists of festivals given by the early Christian writers Irenaeus and Tertullian, the early Church Fathers John Chrysostom, Augustine of Hippo, and Jerome attested to December 25 as the date of Christmas toward the end of the fourth century.", "December 25 was the traditional date of the winter solstice in the Roman Empire, where most Christians lived, and the Roman festival (birthday of , the 'Invincible Sun') had been held on this date since 274 AD.In the East, the birth of Jesus was celebrated in connection with the Epiphany on January 6.This holiday was not primarily about Christ's birth, but rather his baptism.", "Christmas was promoted in the East as part of the revival of Orthodox Christianity that followed the death of the pro-Arian Emperor Valens at the Battle of Adrianople in 378.The feast was introduced in Constantinople in 379, in Antioch by John Chrysostom towards the end of the fourth century, probably in 388, and in Alexandria in the following century.", "The Georgian Iadgari demonstrates that Christmas was celebrated in Jerusalem by the sixth century.", "''The Nativity'', from a 14th-century missal, a liturgical book containing texts and music necessary for the celebration of Mass throughout the yearIn the Early Middle Ages, Christmas Day was overshadowed by Epiphany, which in western Christianity focused on the visit of the magi.", "However, the medieval calendar was dominated by Christmas-related holidays.", "The forty days before Christmas became the \"forty days of St. Martin\" (which began on November 11, the feast of St. Martin of Tours), now known as Advent.", "In Italy, former Saturnalian traditions were attached to Advent.", "Around the 12th century, these traditions transferred again to the Twelve Days of Christmas (December 25 – January 5); a time that appears in the liturgical calendars as Christmastide or Twelve Holy Days.In 567, the Council of Tours put in place the season of Christmastide, proclaiming \"the twelve days from Christmas to Epiphany as a sacred and festive season, and established the duty of Advent fasting in preparation for the feast.\"", "This was done in order to solve the \"administrative problem for the Roman Empire as it tried to coordinate the solar Julian calendar with the lunar calendars of its provinces in the east.", "\"The prominence of Christmas Day increased gradually after Charlemagne was crowned Emperor on Christmas Day in 800.King Edmund the Martyr was anointed on Christmas in 855 and King William I of England was crowned on Christmas Day 1066.The coronation of Charlemagne on Christmas of 800 helped promote the popularity of the holidayBy the High Middle Ages, the holiday had become so prominent that chroniclers routinely noted where various magnates celebrated Christmas.", "King Richard II of England hosted a Christmas feast in 1377 at which 28 oxen and 300 sheep were eaten.", "The Yule boar was a common feature of medieval Christmas feasts.", "Caroling also became popular, and was originally performed by a group of dancers who sang.", "The group was composed of a lead singer and a ring of dancers that provided the chorus.", "Various writers of the time condemned caroling as lewd, indicating that the unruly traditions of Saturnalia and Yule may have continued in this form.", "\"Misrule\"—drunkenness, promiscuity, gambling—was also an important aspect of the festival.", "In England, gifts were exchanged on New Year's Day, and there was special Christmas ale.Christmas during the Middle Ages was a public festival that incorporated ivy, holly, and other evergreens.", "Christmas gift-giving during the Middle Ages was usually between people with legal relationships, such as tenant and landlord.", "The annual indulgence in eating, dancing, singing, sporting, and card playing escalated in England, and by the 17th century the Christmas season featured lavish dinners, elaborate masques, and pageants.", "In 1607, King James I insisted that a play be acted on Christmas night and that the court indulge in games.", "It was during the Reformation in 16th–17th-century Europe that many Protestants changed the gift bringer to the Christ Child or ''Christkindl'', and the date of giving gifts changed from December 6 to Christmas Eve.=== 17th and 18th centuries ===Following the Protestant Reformation, many of the new denominations, including the Anglican Church and Lutheran Church, continued to celebrate Christmas.", "In 1629, the Anglican poet John Milton penned ''On the Morning of Christ's Nativity'', a poem that has since been read by many during Christmastide.", "Donald Heinz, a professor at California State University, states that Martin Luther \"inaugurated a period in which Germany would produce a unique culture of Christmas, much copied in North America.\"", "Among the congregations of the Dutch Reformed Church, Christmas was celebrated as one of the principal evangelical feasts.However, in 17th century England, some groups such as the Puritans strongly condemned the celebration of Christmas, considering it a Catholic invention and the \"trappings of popery\" or the \"rags of the Beast\".", "In contrast, the established Anglican Church \"pressed for a more elaborate observance of feasts, penitential seasons, and saints' days.", "The calendar reform became a major point of tension between the Anglican party and the Puritan party.\"", "The Catholic Church also responded, promoting the festival in a more religiously oriented form.", "King Charles I of England directed his noblemen and gentry to return to their landed estates in midwinter to keep up their old-style Christmas generosity.", "Following the Parliamentarian victory over Charles I during the English Civil War, England's Puritan rulers banned Christmas in 1647.Protests followed as pro-Christmas rioting broke out in several cities and for weeks Canterbury was controlled by the rioters, who decorated doorways with holly and shouted royalist slogans.", "Football, among the sports the Puritans banned on a Sunday, was also used as a rebellious force: when Puritans outlawed Christmas in England in December 1647 the crowd brought out footballs as a symbol of festive misrule.", "The book, ''The Vindication of Christmas'' (London, 1652), argued against the Puritans, and makes note of Old English Christmas traditions, dinner, roast apples on the fire, card playing, dances with \"plow-boys\" and \"maidservants\", old Father Christmas and carol singing.", "During the ban, semi-clandestine religious services marking Christ's birth continued to be held, and people sang carols in secret.Old Father Christmas'', (1686), published after Christmas was reinstated as a holy day in EnglandIt was restored as a legal holiday in England with the Restoration of King Charles II in 1660 when Puritan legislation was declared null and void, with Christmas again freely celebrated in England.", "Many Calvinist clergymen disapproved of Christmas celebration.", "As such, in Scotland, the Presbyterian Church of Scotland discouraged the observance of Christmas, and though James VI commanded its celebration in 1618, attendance at church was scant.", "The Parliament of Scotland officially abolished the observance of Christmas in 1640, claiming that the church had been \"purged of all superstitious observation of days\".", "Whereas in England, Wales and Ireland Christmas Day is a common law holiday, having been a customary holiday since time immemorial, it was not until 1871 that it was designated a bank holiday in Scotland.", "Following the Restoration of Charles II, ''Poor Robin's Almanack'' contained the lines: \"Now thanks to God for Charles return, / Whose absence made old Christmas mourn.", "/ For then we scarcely did it know, / Whether it Christmas were or no.\"", "The diary of James Woodforde, from the latter half of the 18th century, details the observance of Christmas and celebrations associated with the season over a number of years.As in England, Puritans in Colonial America staunchly opposed the observation of Christmas.", "The Pilgrims of New England pointedly spent their first December 25 in the New World working normally.", "Puritans such as Cotton Mather condemned Christmas both because scripture did not mention its observance and because Christmas celebrations of the day often involved boisterous behavior.", "Many non-Puritans in New England deplored the loss of the holidays enjoyed by the laboring classes in England.", "Christmas observance was outlawed in Boston in 1659.The ban on Christmas observance was revoked in 1681 by English governor Edmund Andros, but it was not until the mid-19th century that celebrating Christmas became fashionable in the Boston region.At the same time, Christian residents of Virginia and New York observed the holiday freely.", "Pennsylvania Dutch settlers, predominantly Moravian settlers of Bethlehem, Nazareth, and Lititz in Pennsylvania and the Wachovia settlements in North Carolina, were enthusiastic celebrators of Christmas.", "The Moravians in Bethlehem had the first Christmas trees in America as well as the first Nativity Scenes.", "Christmas fell out of favor in the United States after the American Revolution, when it was considered an English custom.George Washington attacked Hessian (German) mercenaries on the day after Christmas during the Battle of Trenton on December 26, 1776, Christmas being much more popular in Germany than in America at this time.With the atheistic Cult of Reason in power during the era of Revolutionary France, Christian Christmas religious services were banned and the three kings cake was renamed the \"equality cake\" under anticlerical government policies.=== 19th century ===Ebenezer Scrooge and the Ghost of Christmas Present.", "From Charles Dickens's ''A Christmas Carol'', 1843.In the early 19th century, Christmas festivities and services became widespread with the rise of the Oxford Movement in the Church of England that emphasized the centrality of Christmas in Christianity and charity to the poor, along with Washington Irving, Charles Dickens, and other authors emphasizing family, children, kind-heartedness, gift-giving, and Santa Claus (for Irving), or Father Christmas (for Dickens).In the early-19th century, writers imagined Tudor-period Christmas as a time of heartfelt celebration.", "In 1843, Charles Dickens wrote the novel ''A Christmas Carol'', which helped revive the \"spirit\" of Christmas and seasonal merriment.", "Its instant popularity played a major role in portraying Christmas as a holiday emphasizing family, goodwill, and compassion.Dickens sought to construct Christmas as a family-centered festival of generosity, linking \"worship and feasting, within a context of social reconciliation.\"", "Superimposing his humanitarian vision of the holiday, in what has been termed \"Carol Philosophy\", Dickens influenced many aspects of Christmas that are celebrated today in Western culture, such as family gatherings, seasonal food and drink, dancing, games, and a festive generosity of spirit.", "A prominent phrase from the tale, \"Merry Christmas\", was popularized following the appearance of the story.", "This coincided with the appearance of the Oxford Movement and the growth of Anglo-Catholicism, which led a revival in traditional rituals and religious observances.The Queen's Christmas tree at Windsor Castle, published in the ''Illustrated London News'', 1848The term ''Scrooge'' became a synonym for miser, with the phrase \"Bah!", "Humbug!\"", "becoming emblematic of a dismissive attitude of the festive spirit.", "In 1843, the first commercial Christmas card was produced by Sir Henry Cole.", "The revival of the Christmas Carol began with William Sandys's ''Christmas Carols Ancient and Modern'' (1833), with the first appearance in print of \"The First Noel\", \"I Saw Three Ships\", \"Hark the Herald Angels Sing\" and \"God Rest Ye Merry, Gentlemen\", popularized in Dickens's ''A Christmas Carol''.In Britain, the Christmas tree was introduced in the early 19th century by the German-born Queen Charlotte.", "In 1832, the future Queen Victoria wrote about her delight at having a Christmas tree, hung with lights, ornaments, and presents placed round it.", "After her marriage to her German cousin Prince Albert, by 1841 the custom became more widespread throughout Britain.An image of the British royal family with their Christmas tree at Windsor Castle created a sensation when it was published in the ''Illustrated London News'' in 1848.A modified version of this image was published in ''Godey's Lady's Book'', Philadelphia in 1850.By the 1870s, putting up a Christmas tree had become common in America.In America, interest in Christmas had been revived in the 1820s by several short stories by Washington Irving which appear in his ''The Sketch Book of Geoffrey Crayon, Gent.''", "and \"Old Christmas\".", "Irving's stories depicted harmonious warm-hearted English Christmas festivities he experienced while staying in Aston Hall, Birmingham, England, that had largely been abandoned, and he used the tract ''Vindication of Christmas'' (1652) of Old English Christmas traditions, that he had transcribed into his journal as a format for his stories.A Norwegian Christmas, 1846 painting by Adolph TidemandIn 1822, Clement Clarke Moore wrote the poem ''A Visit From St. Nicholas'' (popularly known by its first line: ''Twas the Night Before Christmas'').", "The poem helped popularize the tradition of exchanging gifts, and seasonal Christmas shopping began to assume economic importance.", "This also started the cultural conflict between the holiday's spiritual significance and its associated commercialism that some see as corrupting the holiday.", "In her 1850 book ''The First Christmas in New England'', Harriet Beecher Stowe includes a character who complains that the true meaning of Christmas was lost in a shopping spree.While the celebration of Christmas was not yet customary in some regions in the U.S., Henry Wadsworth Longfellow detected \"a transition state about Christmas here in New England\" in 1856.", "\"The old puritan feeling prevents it from being a cheerful, hearty holiday; though every year makes it more so.\"", "In Reading, Pennsylvania, a newspaper remarked in 1861, \"Even our presbyterian friends who have hitherto steadfastly ignored Christmas—threw open their church doors and assembled in force to celebrate the anniversary of the Savior's birth.", "\"The First Congregational Church of Rockford, Illinois, \"although of genuine Puritan stock\", was 'preparing for a grand Christmas jubilee', a news correspondent reported in 1864.By 1860, fourteen states including several from New England had adopted Christmas as a legal holiday.", "In 1875, Louis Prang introduced the Christmas card to Americans.", "He has been called the \"father of the American Christmas card\".", "On June 28, 1870, Christmas was formally declared a United States federal holiday.=== 20th and 21st centuries ===The Christmas Visit.", "Postcard, During the First World War and particularly (but not exclusively) in 1914, a series of informal truces took place for Christmas between opposing armies.", "The truces, which were organised spontaneously by fighting men, ranged from promises not to shoot (shouted at a distance in order to ease the pressure of war for the day) to friendly socializing, gift giving and even sport between enemies.", "These incidents became a well known and semi-mythologised part of popular memory.", "They have been described as a symbol of common humanity even in the darkest of situations and used to demonstrate to children the ideals of Christmas.Up to the 1950s in the UK, many Christmas customs were restricted to the upper and middle classes.", "Most of the population had not yet adopted many Christmas rituals that later became popular, including Christmas trees.", "Christmas dinner would normally include beef or goose, not turkey as would later be common.", "Children would get fruit and sweets in their stocking rather than elaborate gifts.", "Full celebration of a family Christmas with all the trimmings only became widespread with increased prosperity from the 1950s.", "National papers were published on Christmas Day until 1912.Post was still delivered on Christmas Day until 1961.League football matches continued in Scotland until the 1970s while in England they ceased at the end of the 1950s.Under the state atheism of the Soviet Union, after its foundation in 1917, Christmas celebrations—along with other Christian holidays—were prohibited in public.", "During the 1920s, 1930s, and 1940s, the League of Militant Atheists encouraged school pupils to campaign against Christmas traditions, such as the Christmas tree, as well as other Christian holidays, including Easter; the League established an antireligious holiday to be the 31st of each month as a replacement.", "At the height of this persecution, in 1929, on Christmas Day, children in Moscow were encouraged to spit on crucifixes as a protest against the holiday.", "Instead, the importance of the holiday and all its trappings, such as the Christmas tree and gift-giving, was transferred to the New Year.", "It was not until the dissolution of the Soviet Union in 1991 that the persecution ended and Orthodox Christmas became a state holiday again for the first time in Russia after seven decades.European History Professor Joseph Perry wrote that likewise, in Nazi Germany, \"because Nazi ideologues saw organized religion as an enemy of the totalitarian state, propagandists sought to deemphasize—or eliminate altogether—the Christian aspects of the holiday\" and that \"Propagandists tirelessly promoted numerous Nazified Christmas songs, which replaced Christian themes with the regime's racial ideologies.", "\"As Christmas celebrations began to spread globally even outside traditional Christian cultures, several Muslim-majority countries began to ban the observance of Christmas, claiming it undermined Islam.", "In 2023, public Christmas celebrations were cancelled in Bethlehem, the city synonymous with the birth of Jesus.", "Palestinian leaders of various Christian denominations cited the ongoing Israel–Hamas war in their unanimous decision to cancel celebrations." ], [ "Observance and traditions", "Annunciation Church in Nazareth, 1965Dark brown – countries that do not recognize Christmas on December 25 or January 7 as a public holiday.", "Light brown – countries that do not recognize Christmas as a public holiday, but the holiday is given observance.Many Christians attend church services to celebrate the birth of Jesus Christ.Christmas Day is celebrated as a major festival and public holiday in countries around the world, including many whose populations are mostly non-Christian.", "In some non-Christian areas, periods of former colonial rule introduced the celebration (e.g.", "Hong Kong); in others, Christian minorities or foreign cultural influences have led populations to observe the holiday.", "Countries such as Japan, where Christmas is popular despite there being only a small number of Christians, have adopted many of the cultural aspects of Christmas, such as gift-giving, decorations, and Christmas trees.", "A similar example is in Turkey, being Muslim-majority and with a small number of Christians, where Christmas trees and decorations tend to line public streets during the festival.Many popular customs associated with Christmas developed independently of the commemoration of Jesus's birth, with some claiming that certain elements are Christianized and have origins in pre-Christian festivals that were celebrated by pagan populations who were later converted to Christianity; other scholars reject these claims and affirm that Christmas customs largely developed in a Christian context.", "The prevailing atmosphere of Christmas has also continually evolved since the holiday's inception, ranging from a sometimes raucous, drunken, carnival-like state in the Middle Ages, to a tamer family-oriented and children-centered theme introduced in a 19th-century transformation.", "The celebration of Christmas was banned on more than one occasion within certain groups, such as the Puritans and Jehovah's Witnesses (who do not celebrate birthdays in general), due to concerns that it was too unbiblical.Prior to and through the early Christian centuries, winter festivals were the most popular of the year in many European pagan cultures.", "Reasons included the fact that less agricultural work needed to be done during the winter, as well as an expectation of better weather as spring approached.", "Celtic winter herbs such as mistletoe and ivy, and the custom of kissing under a mistletoe, are common in modern Christmas celebrations in the English-speaking countries.The pre-Christian Germanic peoples—including the Anglo-Saxons and the Norse—celebrated a winter festival called Yule, held in the late December to early January period, yielding modern English ''yule'', today used as a synonym for ''Christmas''.", "In Germanic language-speaking areas, numerous elements of modern Christmas folk custom and iconography may have originated from Yule, including the Yule log, Yule boar, and the Yule goat.", "Often leading a ghostly procession through the sky (the Wild Hunt), the long-bearded god Odin is referred to as \"the Yule one\" and \"Yule father\" in Old Norse texts, while other gods are referred to as \"Yule beings\".", "On the other hand, as there are no reliable existing references to a Christmas log prior to the 16th century, the burning of the Christmas block may have been an early modern invention by Christians unrelated to the pagan practice.Among countries with a strong Christian tradition, a variety of Christmas celebrations have developed that incorporate regional and local cultures.", "For example, in eastern Europe Christmas celebrations incorporated pre-Christian traditions such as the Koleda, which shares parallels with the Christmas carol.=== Church attendance ===Christmas Day (inclusive of its vigil, Christmas Eve), is a Festival in the Lutheran Churches, a solemnity in the Roman Catholic Church, and a Principal Feast of the Anglican Communion.", "Other Christian denominations do not rank their feast days but nevertheless place importance on Christmas Eve/Christmas Day, as with other Christian feasts like Easter, Ascension Day, and Pentecost.", "As such, for Christians, attending a Christmas Eve or Christmas Day church service plays an important part in the recognition of the Christmas season.", "Christmas, along with Easter, is the period of highest annual church attendance.", "A 2010 survey by LifeWay Christian Resources found that six in ten Americans attend church services during this time.", "In the United Kingdom, the Church of England reported an estimated attendance of 2.5million people at Christmas services in 2015.=== Decorations ===Typical Neapolitan nativity scene, or or , in Naples.", "Local crèches are renowned for their ornate decorations and symbolic figurines, often mirroring daily life.Nativity scenes are known from 10th-century Rome.", "They were popularised by Saint Francis of Assisi from 1223, quickly spreading across Europe.", "Different types of decorations developed across the Christian world, dependent on local tradition and available resources, and can vary from simple representations of the crib to far more elaborate sets – renowned manger scene traditions include the colourful in Poland, which imitate Kraków's historical buildings as settings, the elaborate Italian (, and ), or the Provençal crèches in southern France, using hand-painted terracotta figurines called .", "In certain parts of the world, notably Sicily, living nativity scenes following the tradition of Saint Francis are a popular alternative to static crèches.", "The first commercially produced decorations appeared in Germany in the 1860s, inspired by paper chains made by children.", "In countries where a representation of the Nativity scene is very popular, people are encouraged to compete and create the most original or realistic ones.", "Within some families, the pieces used to make the representation are considered a valuable family heirloom.The traditional colors of Christmas decorations are red, green, and gold.", "Red symbolizes the blood of Jesus, which was shed in his crucifixion; green symbolizes eternal life, and in particular the evergreen tree, which does not lose its leaves in the winter; and gold is the first color associated with Christmas, as one of the three gifts of the Magi, symbolizing royalty.The official White House Christmas tree for 1962, displayed in the Entrance Hall and presented by John F. Kennedy and his wife Jackie.The Christmas tree was first used by German Lutherans in the 16th century, with records indicating that a Christmas tree was placed in the Cathedral of Strassburg in 1539, under the leadership of the Protestant Reformer, Martin Bucer.", "In the United States, these \"German Lutherans brought the decorated Christmas tree with them; the Moravians put lighted candles on those trees.\"", "When decorating the Christmas tree, many individuals place a star at the top of the tree symbolizing the Star of Bethlehem, a fact recorded by ''The School Journal'' in 1897.Professor David Albert Jones of Oxford University writes that in the 19th century, it became popular for people to also use an angel to top the Christmas tree in order to symbolize the angels mentioned in the accounts of the Nativity of Jesus.", "Additionally, in the context of a Christian celebration of Christmas, the Christmas tree, being evergreen in colour, is symbolic of Christ, who offers eternal life; the candles or lights on the tree represent the Light of the World—Jesus—born in Bethlehem.", "Christian services for family use and public worship have been published for the blessing of a Christmas tree, after it has been erected.", "The Christmas tree is considered by some as Christianisation of pagan tradition and ritual surrounding the Winter Solstice, which included the use of evergreen boughs, and an adaptation of pagan tree worship; according to eighth-century biographer Æddi Stephanus, Saint Boniface (634–709), who was a missionary in Germany, took an ax to an oak tree dedicated to Thor and pointed out a fir tree, which he stated was a more fitting object of reverence because it pointed to heaven and it had a triangular shape, which he said was symbolic of the Trinity.", "The English language phrase \"Christmas tree\" is first recorded in 1835 and represents an importation from the German language.On Christmas, the Christ Candle in the center of the Advent wreath is traditionally lit in many church services.Since the 16th century, the poinsettia, a native plant from Mexico, has been associated with Christmas carrying the Christian symbolism of the Star of Bethlehem; in that country it is known in Spanish as the ''Flower of the Holy Night''.", "Other popular holiday plants include holly, mistletoe, red amaryllis, and Christmas cactus.Other traditional decorations include bells, candles, candy canes, stockings, wreaths, and angels.", "Both the displaying of wreaths and candles in each window are a more traditional Christmas display.", "The concentric assortment of leaves, usually from an evergreen, make up Christmas wreaths and are designed to prepare Christians for the Advent season.", "Candles in each window are meant to demonstrate the fact that Christians believe that Jesus Christ is the ultimate light of the world.Christmas lights in Verona.Christmas lights and banners may be hung along streets, music played from speakers, and Christmas trees placed in prominent places.", "It is common in many parts of the world for town squares and consumer shopping areas to sponsor and display decorations.", "Rolls of brightly colored paper with secular or religious Christmas motifs are manufactured for the purpose of wrapping gifts.", "In some countries, Christmas decorations are traditionally taken down on Twelfth Night.=== Nativity play ===Children in Oklahoma reenact a Nativity playFor the Christian celebration of Christmas, the viewing of the Nativity play is one of the oldest Christmastime traditions, with the first reenactment of the Nativity of Jesus taking place in 1223 AD in the Italian town of Greccio.", "In that year, Francis of Assisi assembled a Nativity scene outside of his church in Italy and children sung Christmas carols celebrating the birth of Jesus.", "Each year, this grew larger and people travelled from afar to see Francis's depiction of the Nativity of Jesus that came to feature drama and music.", "Nativity plays eventually spread throughout all of Europe, where they remain popular.", "Christmas Eve and Christmas Day church services often came to feature Nativity plays, as did schools and theatres.", "In France, Germany, Mexico and Spain, Nativity plays are often reenacted outdoors in the streets.=== Music and carols ===Christmas carolers in JerseyThe earliest extant specifically Christmas hymns appear in fourth-century Rome.", "Latin hymns such as , written by Ambrose, Archbishop of Milan, were austere statements of the theological doctrine of the Incarnation in opposition to Arianism.", "(\"Of the Father's love begotten\") by the Spanish poet Prudentius ( 413) is still sung in some churches today.", "In the 9th and 10th centuries, the Christmas \"Sequence\" or \"Prose\" was introduced in North European monasteries, developing under Bernard of Clairvaux into a sequence of rhymed stanzas.", "In the 12th century the Parisian monk Adam of St. Victor began to derive music from popular songs, introducing something closer to the traditional Christmas carol.", "Christmas carols in English appear in a 1426 work of John Awdlay who lists twenty five \"caroles of Cristemas\", probably sung by groups of 'wassailers', who went from house to house.Child singers in Bucharest, 1841The songs now known specifically as carols were originally communal folk songs sung during celebrations such as \"harvest tide\" as well as Christmas.", "It was only later that carols began to be sung in church.", "Traditionally, carols have often been based on medieval chord patterns, and it is this that gives them their uniquely characteristic musical sound.", "Some carols like \"Personent hodie\", \"Good King Wenceslas\", and can be traced directly back to the Middle Ages.", "They are among the oldest musical compositions still regularly sung.", "(O Come all ye faithful) appeared in its current form in the mid-18th century.The singing of carols increased in popularity after the Protestant Reformation in the Lutheran areas of Europe, as the Reformer Martin Luther wrote carols and encouraged their use in worship, in addition to spearheading the practice of caroling outside the Mass.", "The 18th-century English reformer Charles Wesley, a founder of Methodism, understood the importance of music to Christian worship.", "In addition to setting many psalms to melodies, he wrote texts for at least three Christmas carols.", "The best known was originally entitled \"Hark!", "How All the Welkin Rings\", later renamed \"Hark!", "The Herald Angels Sing\".Christmas seasonal songs of a secular nature emerged in the late 18th century.", "The Welsh melody for \"Deck the Halls\" dates from 1794, with the lyrics added by Scottish musician Thomas Oliphant in 1862, and the American \"Jingle Bells\" was copyrighted in 1857.Other popular carols include \"The First Noel\", \"God Rest You Merry, Gentlemen\", \"The Holly and the Ivy\", \"I Saw Three Ships\", \"In the Bleak Midwinter\", \"Joy to the World\", \"Once in Royal David's City\" and \"While Shepherds Watched Their Flocks\".", "In the 19th and 20th centuries, African American spirituals and songs about Christmas, based in their tradition of spirituals, became more widely known.", "An increasing number of seasonal holiday songs were commercially produced in the 20th century, including jazz and blues variations.", "In addition, there was a revival of interest in early music, from groups singing folk music, such as The Revels, to performers of early medieval and classical music.One of the most ubiquitous festive songs is \"We Wish You a Merry Christmas\", which originates from the West Country of England in the 1930s.", "Radio has covered Christmas music from variety shows from the 1940s and 1950s, as well as modern-day stations that exclusively play Christmas music from late November through December 25.Hollywood movies have featured new Christmas music, such as \"White Christmas\" in ''Holiday Inn'' and ''Rudolph the Red-Nosed Reindeer''.", "Traditional carols have also been included in Hollywood films, such as \"Hark!", "The Herald Angels Sing\" in ''It's a Wonderful Life'' (1946), and \"Silent Night\" in ''A Christmas Story''.=== Traditional cuisine ===Christmas dinner settingA special Christmas family meal is traditionally an important part of the holiday's celebration, and the food that is served varies greatly from country to country.", "Some regions have special meals for Christmas Eve, such as Sicily, where 12 kinds of fish are served.", "In the United Kingdom and countries influenced by its traditions, a standard Christmas meal includes turkey, goose or other large bird, gravy, potatoes, vegetables, sometimes bread and cider.", "Special desserts are also prepared, such as Christmas pudding, mince pies, Christmas cake, Panettone and Yule log cake.", "A traditional Christmas meal in Central Europe features fried carp or other fish.=== Cards ===Santa and some of his reindeerChristmas cards are illustrated messages of greeting exchanged between friends and family members during the weeks preceding Christmas Day.", "The traditional greeting reads \"wishing you a Merry Christmas and a Happy New Year\", much like that of the first commercial Christmas card, produced by Sir Henry Cole in London in 1843.The custom of sending them has become popular among a wide cross-section of people with the emergence of the modern trend towards exchanging E-cards.Christmas cards are purchased in considerable quantities and feature artwork, commercially designed and relevant to the season.", "The content of the design might relate directly to the Christmas narrative, with depictions of the Nativity of Jesus, or Christian symbols such as the Star of Bethlehem, or a white dove, which can represent both the Holy Spirit and Peace on Earth.", "Other Christmas cards are more secular and can depict Christmas traditions, mythical figures such as Santa Claus, objects directly associated with Christmas such as candles, holly, and baubles, or a variety of images associated with the season, such as Christmastide activities, snow scenes, and the wildlife of the northern winter.Some prefer cards with a poem, prayer, or Biblical verse; while others distance themselves from religion with an all-inclusive \"Season's greetings\".=== Commemorative stamps ===A number of nations have issued commemorative stamps at Christmastide.", "Postal customers will often use these stamps to mail Christmas cards, and they are popular with philatelists.", "These stamps are regular postage stamps, unlike Christmas seals, and are valid for postage year-round.", "They usually go on sale sometime between early October and early December and are printed in considerable quantities.=== Gift giving ===Christmas gifts under a Christmas treeThe exchanging of gifts is one of the core aspects of the modern Christmas celebration, making it the most profitable time of year for retailers and businesses throughout the world.", "On Christmas, people exchange gifts based on the Christian tradition associated with Saint Nicholas, and the gifts of gold, frankincense, and myrrh which were given to the baby Jesus by the Magi.", "The practice of gift giving in the Roman celebration of Saturnalia may have influenced Christian customs, but on the other hand the Christian \"core dogma of the Incarnation, however, solidly established the giving and receiving of gifts as the structural principle of that recurrent yet unique event\", because it was the Biblical Magi, \"together with all their fellow men, who received the gift of God through man's renewed participation in the divine life.\"", "However, Thomas J. Talley holds that the Roman Emperor Aurelian placed the alternate festival on December 25 in order to compete with the growing rate of the Christian Church, which had already been celebrating Christmas on that date first.==== Gift-bearing figures ====A number of figures are associated with Christmas and the seasonal giving of gifts.", "Among these are Father Christmas, also known as Santa Claus (derived from the Dutch for Saint Nicholas), Père Noël, and the Weihnachtsmann; Saint Nicholas or Sinterklaas; the Christkind; Kris Kringle; Joulupukki; tomte/nisse; Babbo Natale; Saint Basil; and Ded Moroz.", "The Scandinavian tomte (also called nisse) is sometimes depicted as a gnome instead of Santa Claus.Saint Nicholas, known as Sinterklaas in the Netherlands, is considered by many to be the original Santa ClausThe best known of these figures today is red-dressed Santa Claus, of diverse origins.", "The name 'Santa Claus' can be traced back to the Dutch ('Saint Nicholas').", "Nicholas was a 4th-century Greek bishop of Myra, a city in the Roman province of Lycia, whose ruins are from modern Demre in southwest Turkey.", "Among other saintly attributes, he was noted for the care of children, generosity, and the giving of gifts.", "His feast day, December 6, came to be celebrated in many countries with the giving of gifts.Saint Nicholas traditionally appeared in bishop's attire, accompanied by helpers, inquiring about the behaviour of children during the past year before deciding whether they deserved a gift or not.", "By the 13th century, Saint Nicholas was well known in the Netherlands, and the practice of gift-giving in his name spread to other parts of central and southern Europe.", "At the Reformation in 16th- and 17th-century Europe, many Protestants changed the gift bringer to the Christ Child or , corrupted in English to 'Kris Kringle', and the date of giving gifts changed from December 6 to Christmas Eve.The modern popular image of Santa Claus, however, was created in the United States, and in particular in New York.", "The transformation was accomplished with the aid of notable contributors including Washington Irving and the German-American cartoonist Thomas Nast (1840–1902).", "Following the American Revolutionary War, some of the inhabitants of New York City sought out symbols of the city's non-English past.", "New York had originally been established as the Dutch colonial town of New Amsterdam and the Dutch Sinterklaas tradition was reinvented as Saint Nicholas.Current tradition in several Latin American countries (such as Venezuela and Colombia) holds that while Santa makes the toys, he then gives them to the Baby Jesus, who is the one who actually delivers them to the children's homes, a reconciliation between traditional religious beliefs and the iconography of Santa Claus imported from the United States.In Italy's South Tyrol, Austria, the Czech Republic, Southern Germany, Hungary, Liechtenstein, Slovakia, and Switzerland, the Christkind (Ježíšek in Czech, Jézuska in Hungarian and Ježiško in Slovak) brings the presents.", "Greek children get their presents from Saint Basil on New Year's Eve, the eve of that saint's liturgical feast.", "The German St. Nikolaus is not identical with the Weihnachtsmann (who is the German version of Santa Claus / Father Christmas).", "St. Nikolaus wears a bishop's dress and still brings small gifts (usually candies, nuts, and fruits) on December 6 and is accompanied by Knecht Ruprecht.", "Although many parents around the world routinely teach their children about Santa Claus and other gift bringers, some have come to reject this practice, considering it deceptive.Multiple gift-giver figures exist in Poland, varying between regions and individual families.", "St Nicholas () dominates Central and North-East areas, the Starman () is most common in Greater Poland, Baby Jesus () is unique to Upper Silesia, with the Little Star () and the Little Angel () being common in the South and the South-East.", "Grandfather Frost () is less commonly accepted in some areas of Eastern Poland.", "It is worth noting that across all of Poland, St Nicholas is the gift giver on Saint Nicholas Day on December 6.===Sport===Christmas during the Middle Ages was a public festival with annual indulgences included the sporting.", "When Puritans outlawed Christmas in England in December 1647 the crowd brought out footballs as a symbol of festive misrule.", "The Orkney Christmas Day Ba' tradition continues.", "In the former top tier of English football, home and away Christmas Day and Boxing Day double headers were often played guaranteeing football clubs large crowds by allowing many working people their only chance to watch a game.", "Champions Preston North End faced Aston Villa on Christmas Day 1889 and the last December 25 fixture was in 1965 in England, Blackpool beating Blackburn Rovers 4–2.One of the most memorable images of the Christmas truce during World War I was the games of football played between the opposing sides on Christmas Day 1914.More recently, in the United States, both NFL and NBA have held fixtures on Christmas Day." ], [ "Choice of date", "Mosaic in Mausoleum M in the pre-fourth-century necropolis under St Peter's Basilica in Rome, interpreted by some as Jesus represented as ('Christ the Sun').There are two main theories behind December 25 becoming the traditional date for Christmas, although Theology professor Susan Roll says that \"No liturgical historian... goes so far as to deny that it has any sort of relation with the sun, the winter solstice and the popularity of solar worship in the later Roman Empire\".", "December 25 was the date of the winter solstice in the Roman calendar.", "Some early Christian writers noted the solar symbolism in placing Jesus's birthday at the winter solstice and John's birthday at the summer solstice.", "The 'history of religions' theory suggests the Church chose December 25 as Christ's birthday () to appropriate the Roman winter solstice festival (birthday of , the 'Invincible Sun'), held on this date since 274 AD.", "The early Church linked Jesus Christ to the Sun and referred to him as the 'Sun of Righteousness' () prophesied by Malachi.", "Gary Forsythe, Professor of Ancient History, says that the followed \"the seven-day period of the (December 17–23), Rome's most joyous holiday season since Republican times, characterized by parties, banquets, and exchanges of gifts\".Another theory, the 'computation hypothesis' or 'calculation theory', notes that December 25 is nine months after March 25, a date chosen as Jesus's conception (the Annunciation) and the date of the spring equinox on the Roman calendar.=== Date according to Julian calendar ===Some jurisdictions of the Eastern Orthodox Church, including those of Russia, Georgia, Macedonia, Montenegro, Serbia, and Jerusalem, mark feasts using the older Julian calendar.", "As of , there is a difference of 13 days between the Julian calendar and the modern Gregorian calendar, which is used internationally for most secular purposes.", "As a result, December 25 on the Julian calendar currently corresponds to January 7 on the calendar used by most governments and people in everyday life.", "Therefore, the aforementioned Orthodox Christians mark December 25 (and thus Christmas) on the day that is internationally considered to be January 7.However, following the Council of Constantinople in 1923, other Orthodox Christians, such as those belonging to the jurisdictions of Constantinople, Bulgaria, Greece, Romania, Antioch, Alexandria, Albania, Cyprus, Finland, and the Orthodox Church in America, among others, began using the Revised Julian calendar, which at present corresponds exactly to the Gregorian calendar.", "Therefore, these Orthodox Christians mark December 25 (and thus Christmas) on the same day that is internationally considered to be December 25.A further complication is added by the fact that the Armenian Apostolic Church continues the original ancient Eastern Christian practice of celebrating the birth of Christ not as a separate holiday, but on the same day as the celebration of his baptism (Theophany), which is on January 6.This is a public holiday in Armenia, and it is held on the same day that is internationally considered to be January 6, because since 1923 the Armenian Church in Armenia has used the Gregorian calendar.However, there is also a small Armenian Patriarchate of Jerusalem, which maintains the traditional Armenian custom of celebrating the birth of Christ on the same day as Theophany (January 6), but uses the Julian calendar for the determination of that date.", "As a result, this church celebrates \"Christmas\" (more properly called Theophany) on the day that is considered January 19 on the Gregorian calendar in use by the majority of the world.Following the 2022 invasion of its territory by Russia, Ukraine officially moved its Christmas date from January 7 to December 25, to distance itself from the Russian Orthodox Church that had supported Russia's invasion.", "This followed the Orthodox Church of Ukraine formally adopting the Revised Julian calendar for fixed feasts and solemnities.=== Table of dates ===There are four different dates used by different Christian groups to mark the birth of Christ, given in the table below.", "Church or section Calendar Date Gregorian date Note Armenian Patriarchate of Jerusalem Julian calendar January 6 January 19 Correspondence between Julian January 6 and Gregorian January 19 holds until 2100; in the following century the difference will be one day more.", "Armenian Apostolic Church, Armenian Evangelical Church Gregorian calendar January 6 January 6 Eastern Orthodox Church jurisdictions, including those of Constantinople, Bulgaria, Ukraine (state holiday, Orthodox and Greek Catholic), Greece, Romania, Antioch, Alexandria, Albania, Cyprus, Finland, the Orthodox Church in America.Also, the Ancient Church of the East, Syriac Orthodox Church, Indian Orthodox Church.", "Revised Julian calendar December 25 December 25 Revised Julian calendar was agreed at the 1923 Council of Constantinople.Although it follows the Julian calendar, the Ancient Church of the East decided on 2010 to celebrate Christmas according to the Gregorian calendar date.", "Other Eastern Orthodox: Russia, Georgia, Ukrainian Orthodox Church (Moscow Patriarchate), Macedonia, Belarus, Moldova, Montenegro, Serbia and Jerusalem.Also, some Byzantine Rite Catholics and Byzantine Rite Lutherans.", "Julian calendar December 25 January 7 Correspondence between Julian December 25 and Gregorian January 7 of the following year holds until 2100; from 2101 to 2199 the difference will be one day more.", "Coptic Orthodox Church Coptic calendar Koiak 29 or 28 (December 25) January 7 After the Coptic insertion of a leap day in what for the Julian calendar is August (September in Gregorian), Christmas is celebrated on Koiak 28 in order to maintain the exact interval of nine 30-day months and 5 days of the child's gestation.", "Ethiopian Orthodox Tewahedo Church (sole date), Eritrean Orthodox Tewahedo Church (sole date), and P'ent'ay (Ethiopian-Eritrean Evangelical) Churches (primary date) Ethiopian calendar Tahsas 29 or 28 (December 25) January 7 After the Ethiopian and Eritrean insertion of a leap day in what for the Julian calendar is August (September in Gregorian), Christmas (also called Liddet or Gena, also Ledet or Genna) is celebrated on Tahsas 28 in order to maintain the exact interval of nine 30-day months and 5 days of the child's gestation.Most Protestants (P'ent'ay/Evangelicals) in the diaspora have the option of choosing the Ethiopian calendar (Tahsas 29/January 7) or the Gregorian calendar (December 25) for religious holidays, with this option being used when the corresponding eastern celebration is not a public holiday in the western world (with most diaspora Protestants celebrating both days).", "Most Western Christian churches, most Eastern Catholic churches and civil calendars; also the Assyrian Church of the East.", "Gregorian calendar December 25 December 25 The Assyrian Church of the East adopted the Gregorian calendar in 1964." ], [ "Economy", "Christmas decorations at the Galeries Lafayette department store in Paris, France.", "The Christmas season is the busiest trading period for retailers.Christmas market in Jena, GermanyChristmas is typically a peak selling season for retailers in many nations around the world since sales increase dramatically during this time as people purchase gifts, decorations, and supplies to celebrate.", "In the United States, the \"Christmas shopping season\" starts as early as October.", "In Canada, merchants begin advertising campaigns just before Halloween (October 31), and step up their marketing following Remembrance Day on November 11.In the UK and Ireland, the Christmas shopping season starts from mid-November, around the time when high street Christmas lights are turned on.", "In the United States, it has been calculated that a quarter of all personal spending takes place during the Christmas/holiday shopping season.", "Figures from the U.S. Census Bureau reveal that expenditure in department stores nationwide rose from $20.8billion in November 2004 to $31.9billion in December 2004, an increase of 54 percent.", "In other sectors, the pre-Christmas increase in spending was even greater, there being a November–December buying surge of 100 percent in bookstores and 170 percent in jewelry stores.", "In the same year employment in American retail stores rose from 1.6million to 1.8million in the two months leading up to Christmas.", "Industries completely dependent on Christmas include Christmas cards, of which 1.9billion are sent in the United States each year, and live Christmas trees, of which 20.8million were cut in the U.S. in 2002.For 2019, the average US adult was projected to spend $920 on gifts alone.", "In the UK in 2010, up to £8billion was expected to be spent online at Christmas, approximately a quarter of total retail festive sales.money supply in US banks is increased for Christmas shoppingIn most Western nations, Christmas Day is the least active day of the year for business and commerce; almost all retail, commercial and institutional businesses are closed, and almost all industries cease activity (more than any other day of the year), whether laws require such or not.", "In England and Wales, the Christmas Day (Trading) Act 2004 prevents all large shops from trading on Christmas Day.", "Similar legislation was approved in Scotland in 2007.Film studios release many high-budget movies during the holiday season, including Christmas films, fantasy movies or high-tone dramas with high production values to hopes of maximizing the chance of nominations for the Academy Awards.One economist's analysis calculates that, despite increased overall spending, Christmas is a deadweight loss under orthodox microeconomic theory, because of the effect of gift-giving.", "This loss is calculated as the difference between what the gift giver spent on the item and what the gift receiver would have paid for the item.", "It is estimated that in 2001, Christmas resulted in a $4billion deadweight loss in the U.S. alone.", "Because of complicating factors, this analysis is sometimes used to discuss possible flaws in current microeconomic theory.", "Other deadweight losses include the effects of Christmas on the environment and the fact that material gifts are often perceived as white elephants, imposing cost for upkeep and storage and contributing to clutter." ], [ "Controversies", "A 1931 edition of the Soviet magazine , published by the League of Militant Atheists, depicting an Orthodox Christian priest being forbidden to take home a tree for the celebration of Christmastide, which was banned under the Marxist–Leninist doctrine of state atheism.Christmas has at times been the subject of controversy and attacks from various sources, both Christian and non-Christian.", "Historically, it was prohibited by Puritans during their ascendency in the Commonwealth of England (1647–1660), and in Colonial New England where the Puritans outlawed the celebration of Christmas in 1659 on the grounds that Christmas was not mentioned in Scripture and therefore violated the Reformed regulative principle of worship.", "The Parliament of Scotland, which was dominated by Presbyterians, passed a series of acts outlawing the observance of Christmas between 1637 and 1690; Christmas Day did not become a public holiday in Scotland until 1871.Today, some conservative Reformed denominations such as the Free Presbyterian Church of Scotland and the Reformed Presbyterian Church of North America likewise reject the celebration of Christmas based on the regulative principle and what they see as its non-Scriptural origin.", "Christmas celebrations have also been prohibited by atheist states such as the Soviet Union and more recently majority Muslim states such as Somalia, Tajikistan and Brunei.Some Christians and organizations such as Pat Robertson's American Center for Law and Justice cite alleged attacks on Christmas (dubbing them a \"war on Christmas\").", "Such groups claim that any specific mention of the term \"Christmas\" or its religious aspects is being increasingly censored, avoided, or discouraged by a number of advertisers, retailers, government (prominently schools), and other public and private organizations.", "One controversy is the occurrence of Christmas trees being renamed Holiday trees.", "In the U.S. there has been a tendency to replace the greeting ''Merry Christmas'' with ''Happy Holidays'', which is considered inclusive at the time of the Jewish celebration of Hanukkah.", "In the U.S. and Canada, where the use of the term \"Holidays\" is most prevalent, opponents have denounced its usage and avoidance of using the term \"Christmas\" as being politically correct.", "In 1984, the U.S. Supreme Court ruled in ''Lynch v. Donnelly'' that a Christmas display (which included a Nativity scene) owned and displayed by the city of Pawtucket, Rhode Island, did not violate the First Amendment.", "American Muslim scholar Abdul Malik Mujahid has said that Muslims must treat Christmas with respect, even if they disagree with it.The government of the People's Republic of China officially espouses state atheism, and has conducted antireligious campaigns to this end.", "In December 2018, officials raided Christian churches prior to Christmastide and coerced them to close; Christmas trees and Santa Clauses were also forcibly removed." ], [ "See also", "* Apollo 8 Genesis reading from lunar orbit, December 24, 1968* * * * List of Christmas films* * * * Mithraism in comparison with other belief systems#25th of December*" ], [ "Notes" ], [ "References" ], [ "Further reading", "* Bowler, Gerry, ''The World Encyclopedia of Christmas'' (October 2004: McClelland & Stewart).", "* Bowler, Gerry, ''Santa Claus: A Biography'' (November 2007: McClelland & Stewart).", "* Comfort, David, ''Just Say Noel: A History of Christmas from the Nativity to the Nineties'' (November 1995: Fireside).", "* Count, Earl W., ''4000 Years of Christmas: A Gift from the Ages'' (November 1997: Ulysses Press).", "* Federer, William J., '' There Really Is a Santa Claus: The History of St. Nicholas & Christmas Holiday Traditions '' (December 2002: Amerisearch).", "* Kelly, Joseph F., '' The Origins of Christmas '' (August 2004: Liturgical Press).", "* Miles, Clement A., '' Christmas Customs and Traditions '' (1976: Dover Publications).", "* Nissenbaum, Stephen, ''The Battle for Christmas'' (1996; New York: Vintage Books, 1997).", "* * Rosenthal, Jim, ''St.", "Nicholas: A Closer Look at Christmas'' (July 2006: Nelson Reference).", "* * *" ], [ "External links", "* '' Christmas: Its Origin and Associations'', by William Francis Dawson, 1902, from Project Gutenberg" ] ]
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[ [ "Contraction mapping" ], [ "Introduction", " In mathematics, a '''contraction mapping''', or '''contraction''' or '''contractor''', on a metric space (''M'', ''d'') is a function ''f'' from ''M'' to itself, with the property that there is some real number such that for all ''x'' and ''y'' in ''M'',:The smallest such value of ''k'' is called the '''Lipschitz constant''' of ''f''.", "Contractive maps are sometimes called '''Lipschitzian maps'''.", "If the above condition is instead satisfied for''k'' ≤ 1, then the mapping is said to be a non-expansive map.More generally, the idea of a contractive mapping can be defined for maps between metric spaces.", "Thus, if (''M'', ''d'') and (''N'', ''d''') are two metric spaces, then is a contractive mapping if there is a constant such that:for all ''x'' and ''y'' in ''M''.Every contraction mapping is Lipschitz continuous and hence uniformly continuous (for a Lipschitz continuous function, the constant ''k'' is no longer necessarily less than 1).A contraction mapping has at most one fixed point.", "Moreover, the Banach fixed-point theorem states that every contraction mapping on a non-empty complete metric space has a unique fixed point, and that for any ''x'' in ''M'' the iterated function sequence ''x'', ''f'' (''x''), ''f'' (''f'' (''x'')), ''f'' (''f'' (''f'' (''x''))), ... converges to the fixed point.", "This concept is very useful for iterated function systems where contraction mappings are often used.", "Banach's fixed-point theorem is also applied in proving the existence of solutions of ordinary differential equations, and is used in one proof of the inverse function theorem.Contraction mappings play an important role in dynamic programming problems." ], [ "Firmly non-expansive mapping", "A non-expansive mapping with can be generalized to a '''firmly non-expansive mapping''' in a Hilbert space if the following holds for all ''x'' and ''y'' in ::where:.This is a special case of averaged nonexpansive operators with .", "A firmly non-expansive mapping is always non-expansive, via the Cauchy–Schwarz inequality.The class of firmly non-expansive maps is closed under convex combinations, but not compositions.", "This class includes proximal mappings of proper, convex, lower-semicontinuous functions, hence it also includes orthogonal projections onto non-empty closed convex sets.", "The class of firmly nonexpansive operators is equal to the set of resolvents of maximally monotone operators.", "Surprisingly, while iterating non-expansive maps has no guarantee to find a fixed point (e.g.", "multiplication by -1), firm non-expansiveness is sufficient to guarantee global convergence to a fixed point, provided a fixed point exists.", "More precisely, if , then for any initial point , iteratingyields convergence to a fixed point .", "This convergence might be weak in an infinite-dimensional setting." ], [ "Subcontraction map", "A '''subcontraction map''' or '''subcontractor''' is a map ''f'' on a metric space (''M'', ''d'') such that::If the image of a subcontractor ''f'' is compact, then ''f'' has a fixed point." ], [ "Locally convex spaces", "In a locally convex space (''E'', ''P'') with topology given by a set ''P'' of seminorms, one can define for any ''p'' ∈ ''P'' a ''p''-contraction as a map ''f'' such that there is some ''k''''p'' ''n''+1 = ''f''(''x''''n''), and if (''E'', ''P'') is Hausdorff, then the fixed point is unique." ], [ "See also", "* Short map* Contraction (operator theory)* Transformation" ], [ "References" ], [ "Further reading", "* provides an undergraduate level introduction.", "* * * *" ] ]
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[ [ "Covalent bond" ], [ "Introduction", "A covalent bond forming H2 (right) where two hydrogen atoms share the two electronsA '''covalent bond''' is a chemical bond that involves the sharing of electrons to form electron pairs between atoms.", "These electron pairs are known as '''shared pairs''' or '''bonding pairs'''.", "The stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.", "For many molecules, the sharing of electrons allows each atom to attain the equivalent of a full valence shell, corresponding to a stable electronic configuration.", "In organic chemistry, covalent bonding is much more common than ionic bonding.Covalent bonding also includes many kinds of interactions, including σ-bonding, π-bonding, metal-to-metal bonding, agostic interactions, bent bonds, three-center two-electron bonds and three-center four-electron bonds.", "The term ''covalent bond'' dates from 1939.The prefix ''co-'' means ''jointly, associated in action, partnered to a lesser degree, '' etc.", "; thus a \"co-valent bond\", in essence, means that the atoms share \"valence\", such as is discussed in valence bond theory.In the molecule , the hydrogen atoms share the two electrons via covalent bonding.", "Covalency is greatest between atoms of similar electronegativities.", "Thus, covalent bonding does not necessarily require that the two atoms be of the same elements, only that they be of comparable electronegativity.", "Covalent bonding that entails the sharing of electrons over more than two atoms is said to be delocalized." ], [ "History", "Early concepts in covalent bonding arose from this kind of image of the molecule of methane.", "Covalent bonding is implied in the Lewis structure by indicating electrons shared between atoms.The term ''covalence'' in regard to bonding was first used in 1919 by Irving Langmuir in a ''Journal of the American Chemical Society'' article entitled \"The Arrangement of Electrons in Atoms and Molecules\".", "Langmuir wrote that \"we shall denote by the term ''covalence'' the number of pairs of electrons that a given atom shares with its neighbors.", "\"The idea of covalent bonding can be traced several years before 1919 to Gilbert N. Lewis, who in 1916 described the sharing of electron pairs between atoms (and in 1926 he also coined the term \"photon\" for the smallest unit of radiant energy).", "He introduced the ''Lewis notation'' or ''electron dot notation'' or ''Lewis dot structure'', in which valence electrons (those in the outer shell) are represented as dots around the atomic symbols.", "Pairs of electrons located between atoms represent covalent bonds.", "Multiple pairs represent multiple bonds, such as double bonds and triple bonds.", "An alternative form of representation, not shown here, has bond-forming electron pairs represented as solid lines.Lewis proposed that an atom forms enough covalent bonds to form a full (or closed) outer electron shell.", "In the diagram of methane shown here, the carbon atom has a valence of four and is, therefore, surrounded by eight electrons (the octet rule), four from the carbon itself and four from the hydrogens bonded to it.", "Each hydrogen has a valence of one and is surrounded by two electrons (a duet rule) – its own one electron plus one from the carbon.", "The numbers of electrons correspond to full shells in the quantum theory of the atom; the outer shell of a carbon atom is the ''n'' = 2 shell, which can hold eight electrons, whereas the outer (and only) shell of a hydrogen atom is the ''n'' = 1 shell, which can hold only two.While the idea of shared electron pairs provides an effective qualitative picture of covalent bonding, quantum mechanics is needed to understand the nature of these bonds and predict the structures and properties of simple molecules.", "Walter Heitler and Fritz London are credited with the first successful quantum mechanical explanation of a chemical bond (molecular hydrogen) in 1927.Their work was based on the valence bond model, which assumes that a chemical bond is formed when there is good overlap between the atomic orbitals of participating atoms." ], [ "Types of covalent bonds", "Atomic orbitals (except for s orbitals) have specific directional properties leading to different types of covalent bonds.", "Sigma (σ) bonds are the strongest covalent bonds and are due to head-on overlapping of orbitals on two different atoms.", "A single bond is usually a σ bond.", "Pi (π) bonds are weaker and are due to lateral overlap between p (or d) orbitals.", "A double bond between two given atoms consists of one σ and one π bond, and a triple bond is one σ and two π bonds.Covalent bonds are also affected by the electronegativity of the connected atoms which determines the chemical polarity of the bond.", "Two atoms with equal electronegativity will make nonpolar covalent bonds such as H–H.", "An unequal relationship creates a polar covalent bond such as with H−Cl.", "However polarity also requires geometric asymmetry, or else dipoles may cancel out, resulting in a non-polar molecule." ], [ "Covalent structures", "There are several types of structures for covalent substances, including individual molecules, molecular structures, macromolecular structures and giant covalent structures.", "Individual molecules have strong bonds that hold the atoms together, but generally, there are negligible forces of attraction between molecules.", "Such covalent substances are usually gases, for example, HCl, SO2, CO2, and CH4.In molecular structures, there are weak forces of attraction.", "Such covalent substances are low-boiling-temperature liquids (such as ethanol), and low-melting-temperature solids (such as iodine and solid CO2).", "Macromolecular structures have large numbers of atoms linked by covalent bonds in chains, including synthetic polymers such as polyethylene and nylon, and biopolymers such as proteins and starch.", "Network covalent structures (or giant covalent structures) contain large numbers of atoms linked in sheets (such as graphite), or 3-dimensional structures (such as diamond and quartz).", "These substances have high melting and boiling points, are frequently brittle, and tend to have high electrical resistivity.", "Elements that have high electronegativity, and the ability to form three or four electron pair bonds, often form such large macromolecular structures." ], [ "One- and three-electron bonds", "Lewis and MO diagrams of an individual 2e- bond and 3e- bondBonds with one or three electrons can be found in radical species, which have an odd number of electrons.", "The simplest example of a 1-electron bond is found in the dihydrogen cation, .", "One-electron bonds often have about half the bond energy of a 2-electron bond, and are therefore called \"half bonds\".", "However, there are exceptions: in the case of dilithium, the bond is actually stronger for the 1-electron than for the 2-electron Li2.This exception can be explained in terms of hybridization and inner-shell effects.The simplest example of three-electron bonding can be found in the helium dimer cation, .", "It is considered a \"half bond\" because it consists of only one shared electron (rather than two); in molecular orbital terms, the third electron is in an anti-bonding orbital which cancels out half of the bond formed by the other two electrons.", "Another example of a molecule containing a 3-electron bond, in addition to two 2-electron bonds, is nitric oxide, NO.", "The oxygen molecule, O2 can also be regarded as having two 3-electron bonds and one 2-electron bond, which accounts for its paramagnetism and its formal bond order of 2.Chlorine dioxide and its heavier analogues bromine dioxide and iodine dioxide also contain three-electron bonds.Molecules with odd-electron bonds are usually highly reactive.", "These types of bond are only stable between atoms with similar electronegativities." ], [ "Resonance", "There are situations whereby a single Lewis structure is insufficient to explain the electron configuration in a molecule and its resulting experimentally-determined properties, hence a superposition of structures is needed.", "The same two atoms in such molecules can be bonded differently in different Lewis structures (a single bond in one, a double bond in another, or even none at all), resulting in a non-integer bond order.", "The nitrate ion is one such example with three equivalent structures.", "The bond between the nitrogen and each oxygen is a double bond in one structure and a single bond in the other two, so that the average bond order for each N–O interaction is = .400px=== Aromaticity ===In organic chemistry, when a molecule with a planar ring obeys Hückel's rule, where the number of π electrons fit the formula 4''n'' + 2 (where ''n'' is an integer), it attains extra stability and symmetry.", "In benzene, the prototypical aromatic compound, there are 6 π bonding electrons (''n'' = 1, 4''n'' + 2 = 6).", "These occupy three delocalized π molecular orbitals (molecular orbital theory) or form conjugate π bonds in two resonance structures that linearly combine (valence bond theory), creating a regular hexagon exhibiting a greater stabilization than the hypothetical 1,3,5-cyclohexatriene.In the case of heterocyclic aromatics and substituted benzenes, the electronegativity differences between different parts of the ring may dominate the chemical behavior of aromatic ring bonds, which otherwise are equivalent.=== Hypervalence ===Certain molecules such as xenon difluoride and sulfur hexafluoride have higher co-ordination numbers than would be possible due to strictly covalent bonding according to the octet rule.", "This is explained by the three-center four-electron bond (\"3c–4e\") model which interprets the molecular wavefunction in terms of non-bonding highest occupied molecular orbitals in molecular orbital theory and resonance of sigma bonds in valence bond theory.=== Electron deficiency ===In three-center two-electron bonds (\"3c–2e\") three atoms share two electrons in bonding.", "This type of bonding occurs in boron hydrides such as diborane (B2H6), which are often described as electron deficient because there are not enough valence electrons to form localized (2-centre 2-electron) bonds joining all the atoms.", "However the more modern description using 3c–2e bonds does provide enough bonding orbitals to connect all the atoms, so that the molecules can instead be classified as electron-precise.Each such bond (2 per molecule in diborane) contains a pair of electrons which connect the boron atoms to each other in a banana shape, with a proton (the nucleus of a hydrogen atom) in the middle of the bond, sharing electrons with both boron atoms.", "In certain cluster compounds, so-called four-center two-electron bonds also have been postulated." ], [ "Quantum mechanical description", "After the development of quantum mechanics, two basic theories were proposed to provide a quantum description of chemical bonding: valence bond (VB) theory and molecular orbital (MO) theory.", "A more recent quantum description is given in terms of atomic contributions to the electronic density of states.=== Comparison of VB and MO theories ===The two theories represent two ways to build up the electron configuration of the molecule.", "For valence bond theory, the atomic hybrid orbitals are filled with electrons first to produce a fully bonded valence configuration, followed by performing a linear combination of contributing structures (resonance) if there are several of them.", "In contrast, for molecular orbital theory a linear combination of atomic orbitals is performed first, followed by filling of the resulting molecular orbitals with electrons.The two approaches are regarded as complementary, and each provides its own insights into the problem of chemical bonding.", "As valence bond theory builds the molecular wavefunction out of localized bonds, it is more suited for the calculation of bond energies and the understanding of reaction mechanisms.", "As molecular orbital theory builds the molecular wavefunction out of delocalized orbitals, it is more suited for the calculation of ionization energies and the understanding of spectral absorption bands.At the qualitative level, both theories contain incorrect predictions.", "Simple (Heitler–London) valence bond theory correctly predicts the dissociation of homonuclear diatomic molecules into separate atoms, while simple (Hartree–Fock) molecular orbital theory incorrectly predicts dissociation into a mixture of atoms and ions.", "On the other hand, simple molecular orbital theory correctly predicts Hückel's rule of aromaticity, while simple valence bond theory incorrectly predicts that cyclobutadiene has larger resonance energy than benzene.Although the wavefunctions generated by both theories at the qualitative level do not agree and do not match the stabilization energy by experiment, they can be corrected by configuration interaction.", "This is done by combining the valence bond covalent function with the functions describing all possible ionic structures or by combining the molecular orbital ground state function with the functions describing all possible excited states using unoccupied orbitals.", "It can then be seen that the simple molecular orbital approach overestimates the weight of the ionic structures while the simple valence bond approach neglects them.", "This can also be described as saying that the simple molecular orbital approach neglects electron correlation while the simple valence bond approach overestimates it.Modern calculations in quantum chemistry usually start from (but ultimately go far beyond) a molecular orbital rather than a valence bond approach, not because of any intrinsic superiority in the former but rather because the MO approach is more readily adapted to numerical computations.", "Molecular orbitals are orthogonal, which significantly increases the feasibility and speed of computer calculations compared to nonorthogonal valence bond orbitals.=== Covalency from atomic contribution to the electronic density of states ===In COOP, COHP and BCOOP, evaluation of bond covalency is dependent on the basis set.", "To overcome this issue, an alternative formulation of the bond covalency can be provided in this way.The center mass of an atomic orbital with quantum numbers for atom A is defined as:where is the contribution of the atomic orbital of the atom A to the total electronic density of states of the solid:where the outer sum runs over all atoms A of the unit cell.", "The energy window is chosen in such a way that it encompasses all of the relevant bands participating in the bond.", "If the range to select is unclear, it can be identified in practice by examining the molecular orbitals that describe the electron density along with the considered bond.The relative position of the center mass of levels of atom A with respect to the center mass of levels of atom B is given as:where the contributions of the magnetic and spin quantum numbers are summed.", "According to this definition, the relative position of the A levels with respect to the B levels is:where, for simplicity, we may omit the dependence from the principal quantum number in the notation referring to In this formalism, the greater the value of the higher the overlap of the selected atomic bands, and thus the electron density described by those orbitals gives a more covalent bond.", "The quantity is denoted as the ''covalency'' of the bond, which is specified in the same units of the energy ." ], [ "Analogous effect in nuclear systems", "An analogous effect to covalent binding is believed to occur in some nuclear systems, with the difference that the shared fermions are quarks rather than electrons.", "High energy proton-proton scattering cross-section indicates that quark interchange of either u or d quarks is the dominant process of the nuclear force at short distance.", "In particular, it dominates over the Yukawa interaction where a meson is exchanged.", "Therefore, covalent binding by quark interchange is expected to be the dominating mechanism of nuclear binding at small distance when the bound hadrons have covalence quarks in common." ], [ "See also", "* Bonding in solids* Bond order* Coordinate covalent bond, also known as a dipolar bond or a dative covalent bond* Covalent bond classification (or LXZ notation)* Covalent radius* Disulfide bond* Hybridization* Hydrogen bond* Ionic bond* Linear combination of atomic orbitals* Metallic bonding* Noncovalent bonding* Resonance (chemistry)" ], [ "References" ], [ "Sources", "* * *" ], [ "External links", "* Covalent Bonds and Molecular Structure * Structure and Bonding in Chemistry—Covalent Bonds" ] ]
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[ [ "Condensation polymer" ], [ "Introduction", "Polyethylene terephthalate (PET) is a common condensation polymer.In polymer chemistry, '''condensation polymers''' are any kind of polymers whose process of polymerization involves a condensation reaction (i.e.", "a small molecule, such as water or methanol, is produced as a byproduct).", "Natural proteins as well as some common plastics such as nylon and PETE are formed in this way.", "Condensation polymers are formed by polycondensation, when the polymer is formed by condensation reactions between species of all degrees of polymerization, or by condensative chain polymerization, when the polymer is formed by sequential addition of monomers to an active site in a chain reaction.", "The main alternative forms of polymerization are chain polymerization and polyaddition, both of which give addition polymers.IUPAC definition for polycondensation in polymer chemistryCondensation polymerization is a form of step-growth polymerization.", "Linear polymers are produced from bifunctional monomers, i.e.", "compounds with two reactive end-groups.", "Common condensation polymers include polyesters, polyamides such as nylon, polyacetals, and proteins." ], [ "Polyamides", "One important class of condensation polymers are polyamides.", "They arise from the reaction of carboxylic acid and an amine.", "Examples include nylons and proteins.", "When prepared from amino-carboxylic acids, e.g.", "amino acids, the stoichiometry of the polymerization includes co-formation of water::n H2N-X-CO2H → HN-X-C(O)n + (n-1) H2OWhen prepared from diamines and dicarboxylic acids, e.g.", "the production of nylon 66, the polymerization produces two molecules of water per repeat unit::n H2N-X-NH2 + n HO2C-Y-CO2H → HN-X-NHC(O)-Y-C(O)n + (2n-1) H2O:General chemical structure of one type of condensation polymer" ], [ "Polyesters", "Another important class of condensation polymers are polyesters.", "They arise from the reaction of a carboxylic acid and an alcohol.", "An example is polyethyleneterephthalate, the common plastic PETE (recycling #1 in the USA)::n HO-X-OH + n HO2C-Y-CO2H → O-X-O2C-Y-C(O)n + (2n-1) H2Opoly-(''R'')-3-hydroxybutyrate (P3HB), a naturally-occurring polymer." ], [ "Safety and environmental considerations", "Condensation polymers tend to be more biodegradable than addition polymers.", "The peptide or ester bonds between monomers can be hydrolysed, especially in the presence of catalysts or bacterial enzymes." ], [ "See also", "*Biopolymer*Epoxy resins*Polyamide*Polyester" ], [ "References" ], [ "External links", "* Polymers (and condensation polymers) - Virtual Text of Organic Chemistry, William Reusch" ] ]
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[ [ "Timeline of computing" ], [ "Introduction", "'''Timeline of computing''' presents events in the history of computing organized by year and grouped into six topic areas: predictions and concepts, first use and inventions, hardware systems and processors, operating systems, programming languages, and new application areas.", "'''Detailed computing timelines''': before 1950, 1950–1979, 1980–1989, 1990–1999, 2000–2009, 2010–2019, 2020–present__TOC__" ], [ "Graphical timeline" ], [ "See also", "* History of compiler construction* History of computing hardware – up to third generation (1960s)* History of computing hardware (1960s–present) – third generation and later* History of the graphical user interface* History of the Internet* History of the World Wide Web* List of pioneers in computer science* Timeline of electrical and electronic engineering* Microprocessor chronology" ], [ "Resources", "* Stephen White, ''A Brief History of Computing''* ''The Computer History in time and space, Graphing Project'', an attempt to build a graphical image of computer history, in particular operating systems.", "* *" ], [ "External links", "* Visual History of Computing 1944-2013 (archived)" ] ]
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[ [ "Colorado Springs, Colorado" ], [ "Introduction", "'''Colorado Springs''' is a city in and the county seat of El Paso County, Colorado, United States.", "It is the most populous city in El Paso County, with a population of 478,961 at the 2020 census, a 15.02% increase since 2010.Colorado Springs is the second-most populous city and the most extensive city in the state of Colorado, and the 40th-most populous city in the United States.", "It is the principal city of the Colorado Springs metropolitan area and the second-most prominent city of the Front Range Urban Corridor.", "It is located in east-central Colorado on Fountain Creek, south of Denver.At the city stands over above sea level.", "Colorado Springs is near the base of Pikes Peak, which rises above sea level on the eastern edge of the Southern Rocky Mountains.", "The city is the largest city north of Mexico above 6000 feet in elevation." ], [ "History", "The Ute, Arapaho and Cheyenne peoples were the first recorded inhabiting the area which would become Colorado Springs.", "Part of the territory included in the United States' 1803 Louisiana Purchase, the current city area was designated part of the 1854 Kansas Territory.", "In 1859, after the first local settlement was established, it became part of the Jefferson Territory on October 24 and of El Paso County on November 28.Colorado City at the Front Range confluence of Fountain and Camp creeks was \"formally organized on August13, 1859\" during the Pikes Peak Gold Rush.", "It served as the capital of the Colorado Territory from November 5, 1861, until August 14, 1862, when the capital was moved to Golden, before it was finally moved to Denver in 1867.So many immigrants from England had settled in Colorado Springs by the early 1870s that Colorado Springs was locally referred to as \"Little London.\"", "In 1871 the Colorado Springs Company laid out the towns of La Font (later called Manitou Springs) and '''Fountain Colony''', upstream and downstream respectively, of Colorado City.", "Within a year, Fountain Colony was renamed Colorado Springs and officially incorporated.", "The El Paso County seat shifted from Colorado City in 1873 to the Town of Colorado Springs.", "On December 1, 1880, Colorado Springs expanded northward with two annexations.The second period of annexations was during 188990, and included Seavey's Addition, West Colorado Springs, East End, and another North End addition.", "In 1891 the Broadmoor Land Company built the Broadmoor suburb, which included the Broadmoor Casino, and by December 12, 1895, the city had \"four Mining Exchanges and 275 mining brokers.\"", "By 1898, the city was designated into quadrants by the north-south Cascade Avenue and the east-west Washington/Pikes Peak avenues.From 1899 to 1901 Tesla Experimental Station operated on Knob Hill, and aircraft flights to the Broadmoor's neighboring fields began in 1919.Alexander Airport north of the city opened in 1925, and in 1927 the original Colorado Springs Municipal Airport land was purchased east of the city.The city's military presence began during World War II, beginning with Camp Carson (now the 135,000-acre Fort Carson base) that was established in 1941.During the war, the United States Army Air Forces leased land adjacent to the municipal airfield, naming it Peterson Field in December 1942.In November 1950, Ent Air Force Base was selected as the Cold War headquarters for Air Defense Command (ADC).", "The former WWII Army Air Base, Peterson Field, which had been inactivated at the end of the war, was re-opened in 1951 as a U.S. Air Force base.", "North American Aerospace Defense Command (NORAD) was established as a hardened command and control center within the Cheyenne Mountain Complex during the Cold War.Between 1965 and 1968, the University of Colorado Colorado Springs, Pikes Peak State College and Colorado Technical University were established in or near the city.", "In 1977 most of the former Ent AFB became a US Olympic training center.", "The Libertarian Party was founded within the city in the 1970s.On October 1, 1981, the Broadmoor Addition, Cheyenne Canon, Ivywild, Skyway, and Stratton Meadows were annexed after the Colorado Supreme Court \"overturned a district court decision that voided the annexation\".", "Further annexations expanding the city include the Nielson Addition and Vineyard Commerce Park Annexation in September 2008.On June 23, 2012, the Waldo Canyon fire began 4 miles (6.4 km) northwest of the city.", "The fire ended up destroying 346 homes and killing two people in the city.", "In total, over 32,000 residents had to be evacuated.", "At the time the fire was the most destructive in state history until it was surpassed by the Black Forest Fire the following year." ], [ "Geography", "View of downtown Colorado Springs from the summit of Pikes Peak.View of Colorado Springs and Pikes Peak from the eastern plainsThe city lies in a semi-arid Steppe climate region with the Southern Rocky Mountains to the west, the Palmer Divide to the north, high plains further east, and high desert lands to the south when leaving Fountain and approaching Pueblo.", "Colorado Springs is or one hour and five minutes south of Denver by car using I-25.Colorado Springs has the greatest total area of any municipality in Colorado.", "At the 2020 United States Census, the city had a total area of including of water.===Metropolitan area===Colorado Springs has many features of a modern urban area such as parks, bike trails, and open spaces.", "However, it is not exempt from problems that typically plague cities experiencing tremendous growth such as overcrowded roads and highways, crime, sprawl, and government budgetary issues.", "Many of the problems are indirectly or directly caused by the city's difficulty in coping with the large population growth experienced since 1997, and the annexation of the Banning Lewis Ranch area to accommodate further population growth of 175,000 future residents.===Climate===Nikola Tesla sitting in the Colorado Springs Experimental Station with his \"magnifying transmitter\" generating millions of voltsColorado Springs has a cooler, dry-winter semi-arid climate (Köppen ''BSk''), and its location just east of the Rocky Mountains affords it the rapid warming influence from chinook winds during winter but also subjects it to drastic day-to-day variability in weather conditions.", "The city has abundant sunshine year-round, averaging 243 sunny days per year, and receives approximately of annual precipitation.", "Due to unusually low precipitation for several years after flooding in 1999, Colorado Springs enacted lawn water restrictions in 2002.These were lifted in 2005 but permanently reinstated in December 2019.Colorado Springs is one of the most active lightning strike areas in the United States.", "This natural phenomenon led Nikola Tesla to select Colorado Springs as the preferred location to build his lab and study electricity.====Seasonal climate====View of the city through the clouds on July 1, 2022, taken from the International Space Station with north oriented towards the leftDecember is typically the coldest month, averaging .", "Historically, January had been the coldest month, but, in recent years, December has had both lower daily maxima and minima.", "Typically, there are 5.2 nights with sub- lows and 23.6 days where the high does not rise above freezing.Snowfall is usually moderate and remains on the ground briefly because of direct sun, with the city receiving per season, although the mountains to the west often receive in excess of triple that amount; March is the snowiest month in the region, both by total accumulation and number of days with measurable snowfall.", "In addition, 8 of the top 10 heaviest 24-hour snowfalls have occurred from March to May.", "Summers are warm, with July, the warmest month, averaging , and 18 days of + highs annually.", "Due to the high elevation and aridity, nights are usually relatively cool and rarely does the low remain above .", "Dry weather generally prevails, but brief afternoon thunderstorms are common, especially in July and August when the city receives the majority of its annual rainfall, due to the North American monsoon.The first autumn freeze and the last freeze in the spring, on average, occur on October 2 and May 6, respectively; the average window for measurable snowfall (≥) is October 21 through April 25.Extreme temperatures range from on June 26, 2012 and most recently on June 21, 2016, down to on February 1, 1951, and December 9, 1919.====Climate data=======Cityscape===Panoramic View of Downtown Colorado Springs" ], [ "Demographics", "Map of racial distribution in Colorado Springs, 2010 U.S. Census.", "Each dot is 25 people: As of the 2020 United States Census, the population of the City of Colorado Springs was 478,961 (40th most populous U.S. city), the population of the Colorado Springs Metropolitan Statistical Area was 755,105 (79th most populous MSA), and the population of the Front Range Urban Corridor was 5,055,344.As of the April 2010 census, 78.8% of the population of the city was White (non-Hispanic Whites were 70.7% of the population, compared with 86.6% in 1970), 16.1% Hispanic or Latino of any race (compared with 7.4% in 1970), 6.3% Black or African American, 3.0% Asian, 1.0% descended from indigenous peoples of the Americas, 0.3% descended from indigenous Hawaiians and other Pacific islanders, 5.5% of some other race, and 5.1% of two or more races.", "Mexican Americans made up 14.6% of the city's population, compared with 9.1% in 1990.The median age in the city was 35 years." ], [ "Economy", "Colorado Springs's economy is driven primarily by the military, the high-tech industry, and tourism, in that order.", "The city is experiencing growth in the service sectors.", "In June 2019, before the COVID-19 pandemic, the unemployment rate was 3.3%.", "The state's unemployment rate in June 2022 was 3.4% compared to 3.6% for the nation.===Military===United States Space ForcePeterson Space Force Base Building1, there are nearly 45,000 active-duty troops in Colorado Springs.", "There are more than 100,000 veterans and thousands of reservists.", "The military and defense contractors supply more than 40% of the Pikes Peak region's economy.Colorado Springs is home to the Peterson Space Force Base, Schriever Space Force Base, Cheyenne Mountain Space Force Station, U.S. Space Command, and Space Operations Command— the largest contingent of space service military installations.", "They are responsible for intelligence gathering, space operations, and cyber missions.Peterson Space Force Base is responsible for the North American Aerospace Defense Command (NORAD) and the United States Northern Command (USNORTHCOM) headquarters, Space Operations Command, and Space Deltas 2, 3, and 7.Located at Peterson is the 302nd Airlift Wing, an Air Force Reserve unit, that transports passengers and cargo and fights wildfires.Schriever Space Force Base is responsible for Joint Task Force-Space Defense and Space Deltas 6, 8, and 9.The NORAD and USNORTHCOM Alternate Command Center is located at the Cheyenne Mountain Complex.", "Within the mountain complex, the Cheyenne Mountain Space Force Station has been operated by Space Operations Command.", "On January 13, 2021, the Air Force announced a new permanent home for Space Command, moving it from Colorado Springs to Huntsville, Alabama in 2026, but the decision could be reversed by Congress.President Richard Nixon gives a commencement ceremony speech at the Air Force Academy in Colorado Springs, June 4, 1969.Army divisions are trained and stationed at Fort Carson.", "The United States Air Force Academy was established after World War II, on land donated by the City of Colorado Springs.===Defense industry===The defense industry forms a significant part of the Colorado Springs economy, with some of the city's largest employers being defense contractors.", "Some defense corporations have left or downsized city campuses, but slight growth has been recorded.", "Significant defense corporations in the city include Northrop Grumman, Boeing, General Dynamics, L3Harris Technologies, SAIC, ITT, Lockheed Martin, and Bluestaq.", "The Space Foundation is based in Colorado Springs.===High-tech industry===A large percentage of Colorado Springs's economy is still based on manufacturing high-tech and complex electronic equipment.", "The high-tech sector in the Colorado Springs area has decreased its overall presence from 2000 to 2006 (from around 21,000 to around 8,000), with notable reductions in information technology and complex electronic equipment.", "Current trends project the high-tech employment ratio will continue to decrease.High-tech corporations offering fibre-optics to the premises connections within the city include: Lumen Technologies, Comcast and other providers as of 2023.Hewlett-Packard still has some sales, support, and SAN storage engineering center for the computer industry.", "Storage Networking Industry Association is the home of the SNIA Technology Center.", "Keysight Technologies, spun off in 2014 from Agilent, which was itself spun off from HP in 1999 as an independent, publicly traded company, has its oscilloscope research and development division based in Colorado Springs.", "Intel had 250 employees in 2009.The Intel facility is now used for the centralized unemployment offices, social services, El Paso county offices, and a bitcoin mining facility.", "Microchip Technology (formerly Atmel), is a chip fabrication organization.", "The Apple Inc. facility was sold to Sanmina-SCI in 1996." ], [ "Culture and contemporary life", "===Tourism===Pikes Peak, the easternmost \"fourteener\" in the United StatesAlmost immediately following the arrival of railroads beginning in 1871, the city's location at the base of Pikes Peak and the Rocky Mountains made it a popular tourism destination.", "Tourism is the third largest employer in the Pikes Peak region, accounting for more than 16,000 jobs.", "In 2018, 23 million day and overnight visitors came to the area, contributing $2.4 billion in revenue.Garden of the GodsColorado Springs has more than 55 attractions and activities in the area, including Garden of the Gods park, United States Air Force Academy, the ANA Money Museum, Cheyenne Mountain Zoo, Colorado Springs Fine Arts Center at Colorado College, Old Colorado City, The National Museum of World War II Aviation, and the U.S. Olympic & Paralympic Training Center.", "In 2020, the United States Olympic & Paralympic Museum opened; the Flying W Ranch Chuckwagon Dinner & Western Show reopened in 2020.A new Pikes Peak Summit Complex opened at the 14,115-foot summit in 2021.The Manitou and Pikes Peak Railway also reopened in 2021.The downtown Colorado Springs Visitor Information Center offers free area information to leisure and business travelers.", "The Cultural Office of the Pikes Peak Region (COPPeR), also downtown, supports and advocates for the arts throughout the Pikes Peak Region.", "It operates the PeakRadar website to communicate city events.===Annual cultural events===The Saturday morning launch, overlooking Prospect Lake, in downtown Colorado SpringsColorado Springs is home to the annual Colorado Springs Labor Day Lift Off, a hot air balloon festival that takes place over Labor Day weekend at the city's Memorial Park.Other annual events include: a comic book convention and science fiction convention called GalaxyFest in February, a pride parade called PrideFest in July, the Greek Festival, the Pikes Peak Ascent and Marathon, and the Steers & Beers Whiskey and Beer Festival in August, and the Emma Crawford Coffin Races and Festival in nearby Manitou Springs and Arts Month in October.The Colorado Springs Festival of Lights Parade is held the first Saturday in December.", "The parade is held on Tejon Street in Downtown Colorado Springs.===Breweries===In 2017, Colorado had the third-most craft breweries at 348.Breweries and microbreweries have become popular in Colorado Springs, which hosts over 30 of them.===Religious institutions===Although houses of worship of almost every major world religion are within the city, Colorado Springs has in particular attracted a large influx of Evangelical Christians and Christian organizations in recent years.", "At one time Colorado Springs was the national headquarters for 81 different religious organizations, earning the city the tongue-in-cheek nicknames \"the Evangelical Vatican\" and \"The Christian Mecca.\"", "Religious groups with regional or international headquarters in Colorado Springs include:*Association of Christian Schools International*Biblica*Children's HopeChest*Community Bible Study*Compassion International*David C. Cook/Integrity Music*Development Associates International*Engineering Ministries International *Family Talk*Focus on the Family*Global Action*HCJB*Hope & Home*The Navigators*One Child Matters*Roman Catholic Diocese of Colorado Springs*VisionTrust*WAY-FM Media Group*Young Life===Marijuana===Although Colorado voters approved Colorado Amendment 64, a constitutional amendment in 2012 legalizing retail sales of marijuana for recreational purposes, the Colorado Springs city council voted not to permit retail shops in the city, as was allowed in the amendment.", "Medical marijuana outlets continue to operate in Colorado Springs.", "In 2015, there were 91 medical marijuana clinics in the city, which reported sales of $59.6 million in 2014, up 11 percent from the previous year but without recreational marijuana shops.", "On April 26, 2016, Colorado Springs city council decided to extend the current six-month moratorium to eighteen months with no new licenses to be granted until May 2017.A scholarly paper suggested the city would give up $25.4 million in tax revenue and fees if the city continued to thwart the industry from opening within the city limits.", "As of March 1, 2018, there were 131 medical marijuana centers and no recreational cannabis stores.", "As of 2019 Colorado Springs is still one of seven towns that have only allowed for medical marijuana.===In popular culture===Colorado Springs has been the subject of or setting for many books, films and television shows, and is a frequent backdrop for political thrillers and military-themed stories because of its many military installations and vital importance to the United States' continental defense.", "Notable television series using the city as a setting include ''Dr.", "Quinn, Medicine Woman'', ''Homicide Hunter'' and the ''Stargate'' series ''Stargate SG-1'', as well as the films ''WarGames'', ''The Prestige'', and ''BlacKkKlansman''.In a North Korean propaganda video released in April 2013, Colorado Springs was inexplicably singled out as one of four targets for a missile strike.", "The video failed to pinpoint Colorado Springs on the map, instead showing a spot somewhere in Louisiana." ], [ "Sports", "===Olympic sports===United States Olympic Committee headquarters and training facilityColorado Springs, dubbed Olympic City USA, is home to the United States Olympic & Paralympic Training Center and the headquarters of the United States Olympic & Paralympic Committee and the United States Anti-Doping Agency.Further, over 50 national sports organizations (non-Olympic) headquarter in Colorado Springs.", "These include the National Strength and Conditioning Association, Sports Incubator, a various non-Olympic Sports (such as USA Ultimate), and more.Colorado Springs and Denver hosted the 1962 World Ice Hockey Championships.The city has a long association with the sport of figure skating, having hosted the U.S.", "Figure Skating Championships six times and the World Figure Skating Championships five times.", "It is home to the World Figure Skating Museum and Hall of Fame and the Broadmoor Skating Club, a notable training center for the sport.", "In recent years, the Broadmoor World Arena has hosted skating events such as Skate America and the Four Continents Figure Skating Championships.===Baseball===Colorado Springs is home to a professional baseball team, The Rocky Mountain Vibes who are a member of the Pioneer League an MLB Partner League===Pikes Peak International Hill Climb===The Pikes Peak International Hill Climb (PPIHC), also known as ''The Race to the Clouds,'' is an annual invitational automobile and motorcycle hill climb to the summit of Pikes Peak, every year on the last Sunday of June.", "The highway wasn't completely paved until 2011.===Local professional teams=== Name Sport Founded League Venue Colorado Springs Switchbacks FC Soccer 2015 USL Championship Weidner Field Rocky Mountain Vibes Baseball 2019 Pioneer League UCHealth Park===Local collegiate teams===The local colleges feature many sports teams.", "Notable among them are several nationally competitive NCAA Division I teams: United States Air Force Academy (Falcons) Football, Basketball and Hockey and Colorado College (Tigers) Hockey, and Women's Soccer.===Rodeo===Colorado Springs was the original headquarters of the Professional Bull Riders (PBR) from its founding in 1992 until 2005, when the organization was moved to Pueblo." ], [ "Parks, trails and open space", "The city's Parks, Recreation and Cultural Services manage 136 neighborhood parks, eight community parks, seven regional parks, and five sports complexes, totaling .", "They also manage of trails, of which are park trails and are urban.", "There are of open space in 48 open-space areas.===Parks===Ackerman Overlook, near United States Air Force Academy off Interstate 25 in Colorado Springs, is named for Jasper D. Ackerman (1896–1988), a banker and rancher.Pulpit Rock, in Pikeview (North Colorado Springs)Garden of the Gods is on Colorado Springs's western edge.", "It is a National Natural Landmark, with red/orange sandstone rock formations often viewed against a backdrop of the snow-capped Pikes Peak.", "This park is free to the public and offers many recreational opportunities, such as hiking, rock climbing, cycling, horseback riding and tours.", "It offers a variety of annual events, one of the most popular of which is the Starlight Spectacular, a recreational bike ride held every summer to benefit the Trails and Open Space Coalition of Colorado Springs.Colorado Springs has several major city parks, such as Palmer Park, America the Beautiful Park in downtown, Memorial Park, which includes many sports fields, an indoor swimming pool and skating rink, a skateboard bowl and two half-pipes, and Monument Valley Park, which has walking and biking paths, an outdoor swimming pool and pickleball courts.", "Monument Valley Park also has Tahama Spring, the original spring in Colorado Springs.", "Austin Bluffs Park affords a place of recreation in eastern Colorado Springs.", "El Paso County Regional Parks include Bear Creek Regional Park, Bear Creek Dog Park, Fox Run Regional Park and Fountain Creek Regional Park and Nature Center.", "Ponderosa pine (''Pinus ponderosa''), Gambel oak (''Quercus gambelii''), narrowleaf yucca (''Yucca angustissima'', syn.", "''Yucca glauca'') and prickly pear cactus (''Opuntia macrorhiza'').===Trails===Three trails, the New Santa Fe Regional Trail, Pikes Peak Greenway and Fountain Creek Regional Trail, form a continuous path from Palmer Lake, through Colorado Springs, to Fountain, Colorado.", "The majority of the trail between Palmer Lake and Fountain is a soft surface breeze gravel trail.", "A major segment of the trail within the Colorado Springs city limits is paved.", "The trails, except Monument Valley Park trails, may be used for equestrian traffic.", "Motorized vehicles are not allowed on the trails.", "Many of the trails are interconnected, having main spine trails, like the Pikes Peak Greenway, that lead to secondary trails." ], [ "Government", "Colorado Springs City Hall in 2008On November 2, 2010, Colorado Springs voters adopted a council-strong mayor form of government.", "The City of Colorado Springs transitioned to the new system of government in 2011.Under the council-strong mayor system of government, the mayor is the chief executive and the city council is the legislative branch.", "The mayor is a full-time elected position and not a member of the council.", "The council has nine members, six of whom represent one of six equally populated districts each.", "The remaining three members are elected at-large.Colorado Springs City Hall was built from 1902 to 1904 on land donated by W. S. Stratton.===City Council===The Colorado Springs City Council consists of nine elected officials, six of whom represent districts and three of whom represent the city at-large.", "* District 1 – '''Dave Donelson'''* District 2 – '''Randy Helms''' – ''Council President''* District 3 – '''Michelle Talarico'''* District 4 – '''Yolanda Avila'''* District 5 – '''Nancy Henjum'''* District 6 – '''Mike O'Malley'''* At-large – '''Lynette Crow-Iverson''' - ''Council President Pro Tem''* At-large – '''David Leinweber'''* At-large – '''Brian Risley'''===Politics===In 2017 Caleb Hannan wrote in ''Politico'' that Colorado Springs was \"staunchly Republican\", \"a right-wing counterweight to liberal Boulder\", and that a study ranked it \"the fourth most conservative city in America\".", "In 2016 Hannan wrote that downtown Colorado Springs had a different political vibe from the overall area's and that there were \"superficial signs of changing demographics\".", "Since 2020, Colorado Springs has continued to shift towards the political center.", "In 2022, Governor Jared Polis won the city in his bid for reelection.", "In the 2023 mayoral election, independent candidate Yemi Mobolade handily won the race and became the first elected non-Republican mayor of the city." ], [ "Education", "===Primary and secondary education==='''Public schools'''The public education in the city is divided into several school districts: * Colorado Springs School District 11 (center of the city)* Academy School District 20 (north end)* Falcon School District 49 (east side)* Widefield School District 3 (south end)* Fountain-Fort Carson School District 8 (far south end)* Harrison School District 2 (south central area)* James Irwin Charter High School (east central area)* Cheyenne Mountain School District 12 (southwest corner)* The Vanguard School, CIVA Charter High School and The Classical Academy are charter schools.", "'''Private schools'''* Roman Catholic Diocese of Colorado Springs schools including within the boundaries of the city** Corpus Christi Catholic School - PreK-8** Divine Redeemer Catholic School - PreK-8** St. Gabriel Classical Academy - PreK-3** St. Paul Catholic School - PreK-8* St. Mary's High School - an independent Catholic high school* Fountain Valley School of Colorado - a residential high school established in 1930 with a current enrollment of about 240.", "* The Colorado Springs School - a preK-12 school established in 1962 with a current enrollment of about 300.", "* Colorado Springs Christian Schools - A PreK–12th grade Christian school with two campuses started in 1972 and with an enrollment of about 1,150 in 2021.", "* Evangelical Christian Academy - a preK-12 school established in 1971 with a current enrollment of about 350.", "* Pikes Peak Christian School - a preK-12 Christian school with a current enrollment of about 210 In addition the state of Colorado runs the Colorado School for the Deaf and Blind, a residential school for people up to age 21 and established in 1874, in the city.===Higher education===Doolittle Hall on the campus of the United States Air Force AcademyState institutions offering bachelors and graduate degree programs in Colorado Springs include the University of Colorado at Colorado Springs (UCCS) with more than 12,000 students, and, Pikes Peak State College which offers mostly two-year degree associate degrees.", "The United States Air Force Academy is a federal institution offering bachelor's degrees for officer candidates.Private non-profit institutions include Colorado College established in 1874 with about 2,000 undergraduates.", "Colorado Christian University has its Colorado Springs Center in the city.Private for-profit institutions include Colorado Technical University whose main campus is in Colorado Springs and IntelliTec College a technical training school." ], [ "Transportation", "===Major highways and roads=======Interstate highways====Colorado Springs is primarily served by one interstate highway.", "I-25 runs north and south through Colorado, and traverses the city for nearly , entering the city south of Circle Drive and exiting north of North Gate Boulevard.", "In El Paso County it is known as Ronald Reagan Highway.====State and U.S. highways====A number of state and U.S. highways serve the city.", "State Highway 21 is a major east side semi-expressway from Black Forest to Fountain, known locally and co-signed as Powers Boulevard.", "State Highway 83 runs north–south from central Denver to northern Colorado Springs.", "State Highway 94 runs east–west from western Cheyenne County to eastern Colorado Springs where it terminates at US 24.US 24 is a major route through the city and county, providing access to Woodland Park via Ute Pass to the west and downtown, Nob Hill and numerous suburbs to the east.", "It is co-signed with Platte Ave after SH 21 and originally carried local traffic through town.", "The Martin Luther King Jr Bypass runs from I-25 near Circle Drive along Fountain Blvd to SH 21, then east again.", "State Highway 115 begins in Cañon City, traveling north along the western edge of Fort Carson; when it reaches the city limits it merges with Nevada Avenue, a signed Business Route of US 85.US 85 and SH 115 are concurrent between Lake Avenue and I-25.US 85 enters the city at Fountain and was signed at Venetucci Blvd, Lake Avenue, and Nevada Avenue at various points in history; however most of US 85 is concurrent with I-25 and is not signed.====County and city roads====In November 2015, voters in Colorado Springs overwhelmingly passed ballot measure 2C, dedicating funds from a temporary sales tax increase to much needed road and infrastructure improvements over five years.", "This temporary increase is estimated to bring in approximately $50 million annually, which will be used solely to improve roads and infrastructure.", "The ballot measure passed by a margin of approximately 65–35%.In 2004, the voters of Colorado Springs and El Paso County established the Pikes Peak Rural Transportation Authority.In early 2010, the city of Colorado Springs approved an expansion of the northernmost part of Powers Boulevard in order to create an Interstate 25 bypass commonly referred to as the Copper Ridge Expansion.===Airport===Colorado Springs Airport (COS; ICAO: KCOS) has been in operation since 1925.It is the second-largest commercial airport in the state, after Denver International Airport (DEN; ICAO: KDEN).", "It covers of land at an elevation of approximately .", "COS is considered to be a joint-use civilian and military airport, as Peterson Space Force Base is a tenant of the airport.", "It has three paved runways: 17L/35R is , the runway 17R/35L is and the runway 13/31 is .", "The airport handled 2,134,618 passengers in 2022, and is served by American, Avelo, Delta, Southwest, Sun Country, and United.===Railroads===Freight service is provided by Union Pacific and BNSF.Once an important hub, the city was once served by four Class 1 railroads, as well as a number of smaller operators, some of which were narrow gauge, and an extensive streetcar system, the Colorado Springs and Interurban Railway.Currently there is no intercity passenger service; the last remaining services connecting the Front Range cities ceased with the formation of Amtrak in 1971.Front Range Passenger Rail is a current proposal (as of 2023) to link the cities from Pueblo in the south, north to Fort Collins and possibly Cheyenne, Wyoming.===Bicycling===In April 2018, the Colorado Springs City Council approved a Bike Master Plan.", "The vision of the city's Bike Master Plan is \"a healthy and vibrant Colorado Springs where bicycling is one of many transportation options for a large portion of the population, and where a well-connected and well-maintained network of urban trails, single-track, and on-street infrastructure offers a bicycling experience for present and future generations that is safe, convenient, and fun for getting around, getting in shape, or getting away.\"", "Bike lanes in Colorado Springs have not been deployed without controversy.", "According to ''The Gazette'', their readers \"have mixed feelings for new bike lanes.\"", "In December 2016, the City removed a bike lane along Research Parkway due to overwhelming opposition; an online survey found that 80.5% of respondents opposed the bike lane.", "''The Gazette'' has stated that since the Bike Master Plan was adopted by city council, \"no issue has elicited more argument in ''The Gazette'' pages,\" and due to this immense public interest, on February 25, 2019, ''The Gazette'' hosted a town hall meeting called \"Battle of the Bike Lanes.", "\"===Walkability===A 2011 study by Walk Score ranked Colorado Springs 34th most walkable of fifty largest U.S. cities.A Metro bus arrives at a stop on Colorado Avenue.===Mountain Metropolitan Transit===Mountain Metropolitan Transit (MMT) is testing Battery Electric Buses (BEB), and if the buses perform well, the agency plans to acquire its first three BEBs in 2021 using funds from the Volkswagen emissions scandal and resulting lawsuit and settlement.", "On April 22, 2022, Mountain Metro unveiled four new all-electric Proterra ZX5 buses to be added to their fleet.", "The new buses join their current fleet of 67 clean diesel buses.", "They are funded by the Colorado Department of Transportation Division of Transit and Rail Settlement Transit Bus Replacement Program, Volkswagen Diesel Emission Settlement trust, and Federal transit Administration 5339(b) Buses and Bus Facilities Program grant.", "The Proterra ZX5 buses run 220 to 330 miles on a single charge, and cost $1.2 million per bus.====Mountain Metro Mobility====Mountain Metro Mobility is an Americans with Disabilities Act (ADA) federally mandated complementary ADA paratransit service, which provides demand-response service for individuals with mobility needs that prevent them from using the fixed-route bus system.====Mountain Metro Rides====Mountain Metro Rides offers alternative transportation options to residents of the Pikes Peak Region.", "The program is designed to reduce congestion and pollution by encouraging people to commute by carpool, vanpool, bicycling or walking." ], [ "Neighborhoods and Historic Places", "* Anderosa Neighborhood* Banning Lewis Ranch Neighborhood* Black Forest Neighborhood* Boulder Crescent Place Historic District* Briargate Neighborhood* Broadmoor Neighborhood* Broadmoor Bluffs Neighborhood* Broadmoor Hills Neighborhood* Broadmoor Oaks Neighborhood* Cheyenne Hills Neighborhood* Cimarron Hills Neighborhood* Clearview Estates Neighborhood* Colorado Centre Neighborhood* Columbine Estates Neighborhood* Cragmor Neighborhood* Deerfield Hills Neighborhood* Discovery Neighborhood* Divine Redeemer Neighborhood* Downtown* Eastborough Neighborhood* Falcon Estates Neighborhood* Fountain Valley Ranch Neighborhood* Garden Ranch Neighborhood* Gateway Park Neighborhood* Gleneagle Neighborhood* Historic Uptown Neighborhood* Holland Park Neighborhood* Indian Heights Neighborhood* Interquest Neighborhood* Ivywild Neighborhood* Kettle Creek Neighborhood* Kissing Camels Neighborhood* Knob Hill Neighborhood* Lowell Neighborhood* Manitou Springs* Mesa Neighborhood* Middle Creek Neighborhood* Middle Shooks Run Neighborhood* Mountain Shadows Neighborhood* Northgate Neighborhood* Norwood Neighborhood* Oak Hills Neighborhood* Oak Valley Ranch Neighborhood* Old Colorado City* Old Farm Neighborhood* Old North End Historic District* Park Hill Neighborhood* Patty Jewett Neighborhood* Papeton/Venetian Village Neighborhood* Peregrine Neighborhood* Pheasant Run Ranch Neighborhood* Pikes Peak Park Neighborhood* Pikeview/Pinecliff Neighborhood* Pine Creek Neighborhood* Pinon Valley Neighborhood* Pulpit Rock Neighborhood* Ridgeview Neighborhood* Rockrimmon Neighborhood* Roswell Neighborhood* Rustic Hills Neighborhood* Security* Shooks Run Neighborhood* Southborough Neighborhood* Stetson Hills Neighborhood* Spring Creek Neighborhood* Springs Ranch Neighborhood* Stratmoor Hills Neighborhood* Stratmoor Valley Neighborhood* Stratton Meadows Neighborhood* Sundown Neighborhood* Trailridge Neighborhood* Wagon Trails Neighborhood* Weber-Wahsatch Historic District* Widefield* Wolf Ranch Neighborhood* Venetian Village Neighborhood* Villa Loma Neighborhood* Village Seven NeighborhoodSee also National Register of Historic Places in Colorado Springs, Colorado" ], [ "Notable people" ], [ "Sister cities", "Bishkek mayor Arstanbek Nogoev presents a gift for Colorado Springs mayor Lionel Rivera to a US airman at Manas Air Base, in a ceremony aimed at reviving ties between the two sister cities.Colorado Springs' sister cities are:* Fujiyoshida, Yamanashi, Japan (1962)* Kaohsiung, Taiwan (1983)* Bishkek, Kyrgyzstan (1994)* Nuevo Casas Grandes, Chihuahua, Mexico (1996)* Canterbury-Bankstown, Sydney, New South Wales, Australia (1999)* Olympia, Peloponnese, Greece (2014);Suspended sistership* Smolensk, Smolensk Oblast, Russia (1993–2022)Colorado Springs's sister city organization began when it became partners with Fujiyoshida.", "The ''torii'' gate erected to commemorate the relationship stands at the corner of Bijou Street and Nevada Avenue, and is one of the city's most recognizable landmarks.", "The ''torii'' gate, crisscrossed bridge and shrine, in the median between Platte and Bijou Streets downtown, were a gift to Colorado Springs, erected in 1966 by the Rotary Club of Colorado Springs to celebrate the friendship between the two communities.", "A plaque near the ''torii'' gate states that \"the purpose of the sister city relationship is to promote understanding between the people of our two countries and cities\".", "The Fujiyoshida Student exchange program has become an annual event.In 2006 and 2010, the Bankstown TAP (Talent Advancement Program) performed with the Youth Symphony and the Colorado Springs Children's Chorale as part of the annual \"In Harmony\" program.", "A notable similarity between Colorado Springs and its sister cities is their geographic positions: three of the seven cities are near the foot of a major mountain or mountain range, as is Colorado Springs." ], [ "See also", "*Colorado**Bibliography of Colorado**Index of Colorado-related articles**Outline of Colorado*Club Q nightclub shooting*List of counties in Colorado*List of municipalities in Colorado*List of places in Colorado*List of statistical areas in Colorado**Front Range Urban Corridor**South Central Colorado Urban Area**Colorado Springs, CO Metropolitan Statistical Area*Media in Colorado Springs, Colorado*Tuberculosis treatment in Colorado Springs" ], [ "Notes" ], [ "References" ], [ "External links", "* City of Colorado Springs website* CDOT map of the City of Colorado Springs* Visit Colorado Springs official website" ] ]
wikipedia
[ [ "Professional certification" ], [ "Introduction", "'''Professional certification''', '''trade certification''', or '''professional designation''', often called simply ''certification'' or ''qualification'', is a designation earned by a person to assure qualification to perform a job or task.", "Not all certifications that use post-nominal letters are an acknowledgement of educational achievement, or an agency appointed to safeguard the public interest." ], [ "Overview", "A certification is a third-party attestation of an individual's level of knowledge or proficiency in a certain industry or profession.", "They are granted by authorities in the field, such as professional societies and universities, or by private certificate-granting agencies.", "Most certifications are time-limited; some expire after a period of time (e.g., the lifetime of a product that required certification for use), while others can be renewed indefinitely as long as certain requirements are met.", "Renewal usually requires ongoing education to remain up-to-date on advancements in the field, evidenced by earning the specified number of continuing education credits (CECs), or continuing education units (CEUs), from approved professional development courses.Many certification programs are affiliated with professional associations, trade organizations, or private vendors interested in raising industry standards.", "Certification programs are often created or endorsed by professional associations, but are typically completely independent from membership organizations.", "Certifications are very common in fields such as aviation, construction, technology, environment, and other industrial sectors, as well as healthcare, business, real estate, and finance.According to ''The Guide to National Professional Certification Programs'' (1997) by Phillip Barnhart, \"certifications are portable, since they do not depend on one company's definition of a certain job\" and they provide potential employers with \"an impartial, third-party endorsement of an individual's professional knowledge and experience\".Certification is different from professional licensure.", "In the United States, licenses are typically issued by state agencies, whereas certifications are usually awarded by professional societies or educational institutes.", "Obtaining a certificate is voluntary in some fields, but in others, certification from a government-accredited agency may be legally required to perform certain jobs or tasks.", "In other countries, licenses are typically granted by professional societies or universities and require a certificate after about three to five years and so on thereafter.", "The assessment process for certification may be more comprehensive than that of licensure, though sometimes the assessment process is very similar or even the same, despite differing in terms of legal status.The American National Standards Institute (ANSI) defines the standard for being a certifying agency as meeting the following two requirements:# Delivering an assessment based on industry knowledge that is independent from training courses or course providers# Granting a time-limited credential to anyone who meets the assessment standardsThe Institute for Credentialing Excellence (ICE) is a U.S.-based organization that sets standards for the accreditation of personnel certification and certificate programs based on the ''Standards for Educational and Psychological Testing'', a joint publication of the American Educational Research Association (AERA), the American Psychological Association (APA), and the National Council on Measurement in Education (NCME).", "Many members of the Association of Test Publishers (ATP) are also certification organizations." ], [ "Categorization", "There are three general types of certification.", "Listed in order of development level and portability, they are: corporate (internal), product-specific, and profession-wide.Corporate, or \"internal\" certifications, are made by a corporation or low-stakes organization for internal purposes.", "For example, a corporation might require a one-day training course for all sales personnel, after which they receive a certificate.", "While this certificate has limited portability – to other corporations, for example – it is the most simple to develop.Product-specific certifications are more involved, and are intended to be referenced to a product across all applications.", "This approach is very prevalent in the information technology (IT) industry, where personnel are certified on a version of software or hardware.", "This type of certification is portable across locations (for example, different corporations that use that software), but not across other products.", "Another example could be the certifications issued for shipping personnel, which are under international standards even for the recognition of the certification body, under the International Maritime Organization (IMO).The most general type of certification is profession-wide.", "Certification in the medical profession is often offered by particular specialties.", "In order to apply professional standards, increase the level of practice, and protect the public, a professional organization might establish a certification.", "This is intended to be portable to all places a certified professional might work.", "Of course, this generalization increases the cost of such a program; the process to establish a legally defensible assessment of an entire profession is very extensive.", "An example of this is a certified public accountant (CPA), which would not be certified for just one corporation or one piece of accountancy software but for general work in the profession." ], [ "Professional certificates awarded by tertiary education providers", "Many tertiary education providers grant professional certificates as an award for the completion of an educational program.", "The curriculum of a professional certificate is most often in a focused subject matter.", "Many professional certificates have the same curriculum as master's degrees in the same subject.", "Many other professional certificates offer the same courses as master's degrees in the same subject, but require the student to take fewer total courses to complete the program.", "Some professional certificates have a curriculum that more closely resembles a baccalaureate major in the same field.", "The typical professional certificate program is between 200 and 300 class-hours in size.", "It is uncommon for a program to be larger or smaller than that.", "Most professional certificate programs are open enrollment, but some have admissions processes.", "A few universities put some of their professional certificates into a subclass they refer to as advanced professional certificates.Some of the more commonly offered professional certificates include:* Professional Certificate in Accounting (PCA)* Professional Certificate in Accounting and Finance (PCAF)* Professional Certificate in Taxation (PCIT)* Professional Certificate in Transfer Pricing (PCITP)* Professional Certificate in Contract Management (PCCM)* Professional Certificate in Customer Relationship Management (PCCRM)* Professional Certificate in Facility Management (PCFM)* Professional Certificate in Financial Planning (PCFP)* Professional Certificate in Graphic Design (PCGD)* Professional Certificate in Small Business Management (PCSBM)* Professional Certificate in Human Resources (PCHR)* Professional Certificate in Marketing (PCM)* Professional Certificate in Digital Marketing (PCDM)* Professional Certificate in Paralegal Studies (PCPS)* Professional Certificate in Project Management (PCPM)* Professional Certificate in Supply Chain Management (PCSCM)* Professional Certificate in Store Management (PCSM)* Professional Certificate in Materials Management (PCMM)* Professional Certificate in Technical Communication (PCTC)=== Advanced professional certificate ===''Advanced professional certificates'' are professional credentials designed to help professionals enhance their job performance and marketability in their respective fields.", "In many other countries, certificates are qualifications in higher education.", "In the United States, a certificate may be offered by an institute of higher education.", "These certificates usually signify that a student has reached a standard of knowledge of a certain vocational subject.", "Certificate programs can be completed more quickly than associate degrees and often do not have general education requirements.An advanced professional certificate is a result of an educational process designed for individuals.", "Certificates are designed for both newcomers to the industry as well as seasoned professionals.", "Certificates are awarded by an educational program or academic institution.", "Completion of a certificate program indicates completion of a course or series of courses with a specific concentration that is different from an educational degree program.", "Course content for an advanced certificate is set forth through a variety of sources i.e.", "faculty, committee, instructors, and other subject matter experts in a related field.", "The end goal of an advanced professional certificate is so that professionals may demonstrate knowledge of course content at the end of a set period in time." ], [ "Areas of certification", "=== Accountancy, auditing and finance ===There are many professional bodies for accountants and auditors throughout the world; some of them are legally recognized in their jurisdictions.Public accountants are the accountancy and control experts that are legally certified in different jurisdictions to work in public practices, certifying accounts as statutory auditors, eventually selling advice and services to other individuals and businesses.", "Today, however, many work within private corporations, financial industry, and government bodies.==== Accounting and external auditing ====Cf.", "Accountancy qualifications and regulation* CPA (Chartered Professional Accountant), the unified accounting designation in Canada conferred by CPA Canada.", "* CA or Chartered Accountant conferred by the Institute of Chartered Accountants of India.", "* Institute of Chartered Accountants within the Commonwealth e.g.", "Australia and New Zealand, South Africa, Canada (before merger into CPA).", "With mutual recognition with each other and with the UK* ACA, FCA or CA (Chartered Accountant) conferred by Institutes of Chartered Accountants in various territories, namely the United Kingdom of Great Britain and Northern Ireland and the Republic of Ireland.", "* ACMA or FCMA (Associate or Fellow Chartered Management Accountant) conferred by the Chartered Institute of Management Accountants (UK)* Associate or Fellow Chartered Certified Accountant (ACCA or FCCA) conferred by Association of Chartered Certified Accountants (UK)* AFA or FFA (Associate or Fellow Incorporated Financial Accountant) conferred by the Institute of Financial Accountants (UK)* AAIA or FAIA (Associate or Fellow International Accountant) conferred by Association of International Accountants* MIPA or FIPA (Member or Fellow of the Institute of Public Accountants who use the designation \"Public Accountant\") conferred by the Institute of Public Accountants (Australia)* CPA (Certified Public Accountant) conferred by State Accountancy Boards in the US, Hong-Kong, Canada ...* CMA (Certified Management Accountant) conferred by Institute of Certified Management Accountants (ICMA in Australia), Institute of Management Accountants (IMA in US)* CCC (Chartered Cost Controllers) issued and conferred by the American Academy of Financial Management USA Certifying Board (AAFM)* CFS (Certified Finance Specialist) conferred by IQN==== Internal auditing and fraud combat ====* cAAP (Certified Agile Auditor Professional) awarded by cRisk Academy for proficiency in Agile Auditing* cCAE (Certified Chief Audit Executive) awarded by cRisk Academy for proficiency in starting and running an Internal Audit department* cORCM (Certification in Objective-Centric Risk and Certainty Management) awarded by cRisk Academy * cPIA (Certified Practitioner in Internal Audit) awarded by cRisk Academy for proficiency in Internal Auditing* cRBIA (Certified Risk-Based Internal Auditor) awarded by cRisk Academy for proficiency in Risk-Based Internal Auditing* CIA (Certified Internal Auditor): CCSA, Certification in Control Self Assessment; CGAP, Certified Government Auditing Professional; CRMA, Certification in Risk Management Assurance; QIAL, Qualification in Internal Audit Leadership, conferred by the internationally recognized Institute of Internal Auditors (IIA) headquartered in Lake Mary, Florida, with chapters in many countries* CFE (Certified Fraud Examiner) conferred by the Association of Certified Fraud Examiners (ACFE) headquartered in Texas with chapters in many countries* CFF (Certified in Financial Forensics) awarded by the American Institute of CPAs* CISA (Certified Information Systems Auditor) awarded by the Information Systems Audit and Control Association headquartered in the US with chapters in many countries* CAMS (Certified Anti-Money Laundering Specialist) offered by Association of Certified Anti-Money Laundering Specialists (ACAMS) and advanced CAMS* CGSS (Certified Global Sanctions Specialist) conferred by Association of Certified Anti-Money Laundering Specialists (ACAMS) *CSA (Certified Strategic Auditor) conferred by Association of Certified Strategic Auditors (ACSA) https://www.acsaglobal.com*IACCP (Investment Adviser Certified Compliance Professional) conferred by the Investment Adviser Association (IAA) and National Regulatory Services (NRS)*CPERM (Certified Professional in Enterprise Risk Management) conferred by the Academy of Professional Certification Company (APC) which endorsed by HKSARG==== Finance ====* CFS (Certified Finance Specialist) conferred by IQN* CFA (Chartered Financial Analyst) conferred by CFA Institute (CFA)* ChFM Chartered Financial Manager conferred by International Board of Standards* CIIA (Certified International Investment Analyst) conferred by the Association of Certified International Investment Analysts (ACIIA)*IACCP (Investment Adviser Certified Compliance Professional) conferred by the Investment Adviser Association (IAA) and National Regulatory Services (NRS)===== Investments =====* CFS (Certified Finance Specialist) conferred by IQN* CFA (Chartered Financial Analyst) conferred by CFA Institute (CFA)* ChFM Chartered Financial Manager conferred by International Board of Standards* CIPM (Certificate in Investment Performance Measurement) conferred by CFA Institute (CFA)* CIIA (Certified International Investment Analyst) conferred by the Association of Certified International Investment Analysts (ACIIA)* ASA (Accredited Senior Appraiser), AM (Accredited Member), and CEIV (Certified in Entity and Intangible Valuations) conferred by the American Society of Appraisers* CBV (Chartered Business Valuator) conferred by the CBV Institute.", "* CVA (Certified Valuation Analyst) conferred by the NACVA.", "* CAIA (Chartered Alternative Investment Analyst) conferred by the CAIA Association*IACCP (Investment Adviser Certified Compliance Professional) conferred by the Investment Adviser Association (IAA) and National Regulatory Services (NRS)* FRM (Financial Risk Manager) conferred by Global Association of Risk Professionals (GARP)* PRM (Professional Risk Manager) conferred by Professional Risk Managers' International Association (PRMIA)* FMVA (Financial Modeling and Valuation Analyst) conferred by Corporate Finance Institute (CFI).", "* CQF (Certificate in Quantitative Finance), conferred by the CQF Institute ===== Payroll =====* CPP (Certified Payroll Professional) and FPC (Fundamental Payroll Specialist) conferred by the American Payroll Association.", "* Payroll Compliance Practitioner (PCP) and Certified Payroll Manager (CPM) conferred by the National Payroll Institute===== Personal finance =====* CFS (Certified Finance Specialist) conferred by IQN* CFA (Chartered Financial Analyst) conferred by CFA Institute (CFA)* ChFM Chartered Financial Manager conferred by International Board of Standards* CFP (Certified Financial Planner) conferred by Certified Financial Planner Board of Standards and Financial Planning Standards Board* EA (Enrolled Agent) by the Internal Revenue Service (IRS)* CFC (Certified Financial Consultant) conferred by the Institute of Financial Consultants===== Public finance =====* CCMT (Certified California Municipal Treasurer) conferred by California Municipal Treasurers Association (CMTA)* CGAP (Certified Government Auditing Professional) conferred by the Institute of Internal Auditors, based on the US Government Auditing Standards (Yellow Book) and additionally on COSO, IIA standards and INTOSAI ISSAI standards recognized worldwide in public finance* CDFM (Certified Defense Financial Manager) conferred by American Society of Military Comptrollers (ASMC)* CFO (Certified Financial Officer) conferred by the Carl Vinson Institute of Government of the University of Georgia* CGFM (Certified Government Financial Manager) conferred by Association of Government Accountants (AGA)* CGAT (Certified Governmental Accounting Technician), conferred by Government Finance Officers Association of Alabama* CGFO (Certified Government Finance Officer) conferred by Government Finance Officers Association of Texas (GFOAT)* CGFO (Certified Government Finance Officer), conferred by Florida Government Finance Officers Association (FGFOA)* CGFO (Certified Government Finance Officer) conferred by Louisiana Government Finance Officers Association* CMFO (Certified Municipal Finance Officer) conferred by Government Finance Officers of New Jersey, Rutgers University, and the State of New Jersey* CMFO (Certified Municipal Finance Officer) conferred by Tennessee Comptroller of the Treasury and the Municipal Technical Advisory Service* CPFO (Certified Public Finance Officer) conferred by Government Finance Officers Association* CPFA (Certified Public Finance Administrator) conferred by Association of Public Treasurers of the United States and Canada (APTUSC)* GFO (Government Finance Officer) conferred by Government Finance Officers Association of South Carolina (GFOASC)* North Carolina Local Governmental Finance Officer conferred by North Carolina Government Finance Officers Association and the North Carolina Association of County Finance Officers=== Aging services ===* Certified Aging in Place Specialist (CAPS)* Certified Daily Money Managers* Certified Elder Law* Certified Living in Place (CLIPP)* Certified Senior Advisor (CSA)* Certified At-risk Adult Crime Tactics Specialist (CACTS)* Cognitive Care Certification (CCC)=== Architecture ===* AIA (Member, American Institute of Architects) conferred by American Institute of Architects* FAIA (Fellow, American Institute of Architects) conferred by American Institute of Architects* RA (Registered Architect) conferred by National Council of Architecture Registration Boards* NCARB (Certified) issued by National Council of Architecture Registration Boards – this allows for state-state reciprocity.=== Archival science, information privacy, and records management ===* CA (Certified Archivist), conferred by Academy of Certified Archivists* CIP (Certified Information Professional) conferred by AIIM* CIPM (Certified Information Privacy Manager) conferred by International Association of Privacy Professionals* CIPP (Certified Information Privacy Professional) conferred by International Association of Privacy Professionals* CIPT (Certified Information Privacy Technologist) conferred by International Association of Privacy Professionals* CRA (Certified Records Analyst) conferred by Institute of Certified Records Managers* CRM (Certified Records Manager) conferred by Institute of Certified Records Managers* IGP (Information Governance Professional) conferred by ARMA International=== Aviation ===Aviators are certified through theoretical and in-flight examinations.", "Requirements for certifications are quite equal in most countries and are regulated by each National Aviation Authority.", "The existing certificates or pilot licenses are:* SPL (Sport Pilot License) conferred by the FAA (Federal Aviation Administration)* PPL (Private Pilot License) conferred by the FAA (Federal Aviation Administration) or JAA (Joint Aviation Authorities)* CPL (Commercial Pilot Licence) conferred by the FAA (Federal Aviation Administration) or JAA (Joint Aviation Authorities)* ATP (Airline Transport Pilot) conferred by the FAA (Federal Aviation Administration) or JAA (Joint Aviation Authorities)Licensing in these categories require not only examinations but also a minimum number of flight hours.", "All categories are available for Fixed-Wing Aircraft (airplanes) and Rotatory-Wing Aircraft (helicopters).", "Within each category, aviators may also obtain certifications in:* Instrument Flight Rules (IFR)* Multi-engine aircraft* Turbojet Engines* Jet Engines* Experimental aircraft* Amphibious aircraft* SeaplanesUsually, aviators must be certified also in their log books for the type and model of aircraft they are allowed to fly.", "Currency checks as well as regular medical check-ups with a frequency of 6 months, 12 months, or 36 months, depending on the type of flying permitted, are obligatory.", "An aviator can fly only if holding:* A valid pilot license* A valid medical certificate* Valid certifications for the type of aircraft and type of flight.In Europe, the ANSP, ATCO & ANSP technicians are certified according to EUROCONTROL Safety Regulatory Requirement (ESARRs) (according to EU regulation 2096/2005 \"Common Requirements\").=== Biomedical ===* BMD (Biomedical Electronics Technician) conferred by Electronics Technicians Association* BIET (Biomedical Imaging Electronics Technician) conferred by Electronics Technicians Association=== Business ===* CSA (Certified Strategic Auditor) conferred by Association of Certified Strategic Auditors (ACSA)* CSM (Certified Strategic Manager) conferred by IQN* CPSM (Certified Professional in Supply Management) conferred by Institute for Supply Management (ISM)* CPSD (Certified Professional in Supplier Diversity) conferred by Institute for Supply Management (ISM)=== Chiropractic ====== Communications ===In the United States, several communications certifications are conferred by the Electronics Technicians Association.=== Computer technology ===Certification is often used in the professions of software engineering and information technology.", "* CITP (Chartered IT Professional) conferred by British Computer Society, The Institution of Engineering and Technology and by other professional engineering institutions in the UK and commonwealth=== Contract management ===* CPCM (Certified Professional Contract Manager) conferred by the National Contract Management Association.", "* CPM (Commercial Project Manager) conferred by Commercial Officers Group.", "* CPSM (Certified Professional in Supply Management) conferred by Institute for Supply Management (ISM)=== Dance ===Conferred by the International Dance Council CID at UNESCO, the International Certification of Dance Studies is awarded to students who have completed 150 hours of classes in a specific form of dance for Level 1.Another 150 hours are required for Level 2 and so on till Level 10.This is the only international certification for dance since the International Dance Council CID is the official body for all forms of dance; it is usually given in addition to local or national certificates, that is why it is colloquially called \"the dancer's passport\".", "Students cannot apply for this certification directly – they have to ask their school to apply on their behalf.", "This certification is awarded free of charge, there is no cost other than membership fees.International Dance Council CID at UNESCO administers the International Certification of Dance Studies.=== Data management ===* Business Intelligence and Data Analyst (BIDA) by Corporate Finance Institute (CFI).", "* Certified Data Management Professional (CDMP) by DAMA International.=== Dentistry ====== Electronics ===In the United States, several electronics certifications are provided by the Electronics Technicians Association.=== Emergency management ===The Federal Emergency Management Agency's EMI offers credentials and training opportunities for United States citizens.", "Students do not have to be employed by FEMA or be federal employees for some of the programs.", "* Advance Professional Series (APS) Credential* Continuity Excellence Series, Level I and II* Critical Infrastructure Security and Resilience* Disaster Field Training Operations (DFTO)* Emergency Management Professional Program (EMPP)* Executive Fire Officer Program (EFOP)* Integrated Emergency Management Courses (IEMC)* Master Exercise Practitioner Program (MEPP)* Master Trainer Program (MTP)* Professional Development Series (PDS) Credential* Virtual Table Top Exercise (VTTX) Series=== Engineering ===Professional engineering is any act of planning, designing, composing, measuring, evaluating, inspecting, advising, reporting, directing or supervising, or managing any of the foregoing, that requires the application of engineering principles and that concerns the safeguarding of life, health, property, economic interests, the public interest or the environment.", "* P.Eng.", "(Professional Engineer), conferred by provincial licensing bodies in Canada.", "* Ir.", "or P.Eng.", "(Professional Engineer), conferred by Board of Engineers Malaysia (BEM) in Malaysia.", "* PE (Professional Engineer), conferred by Pakistan Engineering Council (PEC) and state licensing bodies in the United States.", "* PE (Power Engineer), conferred by provincial safety authorities in Canada.", "* EUR ING (European Engineer), conferred by the European Federation of National Engineering Associations (FEANI).", "* C.Eng.", "(Chartered Engineer), conferred by professional engineering institutions in the UK and commonwealth.", "* SMIEEE (Senior member of the IEEE), a professional designation throughout all of the United States.", "* CET (certified engineering technologist) or AScT (applied science technologist), conferred by provincial licensing bodies in Canada.", "* SPE Society of Petroleum Engineers Certificate Is a program whereby it certifies the technical knowledge of petroleum engineers.", "The certification is granted based on an examination in conjunction with experience of the applicant.=== Event planning ===Event planning includes budgeting, scheduling, site selection, acquiring necessary permits, coordinating transportation and parking, arranging for speakers or entertainers, arranging decor, event security, catering, coordinating with third-party vendors, and emergency plans.Common event planning certifications include:* CMP: Certified Meeting Professional* CSEP: Certified Special Events Professional* CPCE: Certified Professional in Catering and Events* CGMP: Certified Government Meeting Professional* CWEP: Certified Wedding & Event Planner=== Facility management ===Facility management can be defined as an aspect of engineering management science that deals with the planning, designing, coordination of space and maintenance of a built environment to enhance quality service management system.", "Service Quality System includes activities like security, maintenance, catering, and external as well as internal cleaning.", "In general, it is also the coordination and harmonization of various specialist disciplines to create the best possible working environment for staff.Facility management is an interdisciplinary field devoted to the coordination of space, infrastructure, people and organization, often associated with the administration of office blocks, arenas, schools, convention centers, shopping complexes, hospitals, hotels, etc.", "However, FM facilitates on a wider range of activities than just business services and these are referred to as non-core functions.", "*FMP- Facility Management Professional*CFM- Certified Facility Manager*SFP- Sustainability Facility Professional=== Warehousing management ===A warehouse management system (WMS) is a part of the supply chain and primarily aims to control the movement and storage of materials within a warehouse and process the associated transactions, including shipping, receiving, putaway and picking.", "The systems also direct and optimize stock putaway based on real-time information about the status of bin utilization.", "A WMS monitors the progress of products through the warehouse.", "It involves the physical warehouse infrastructure, tracking systems, and communication between product stations.More precisely, warehouse management involves the receipt, storage and movement of goods, (normally finished goods), to intermediate storage locations or to a final customer.", "In the multi-echelon model for distribution, there may be multiple levels of warehouses.", "This includes a central warehouse, a regional warehouses (serviced by the central warehouse) and potentially retail warehouses (serviced by the regional warehouses).=== Environment ===* CEnvP – Certified Environmental Practitioner ''of Australia and New Zealand'' (CEnvP)*Chartered Environmentalist (CEnv), Society for the Environment (UK)*MIEMA - Full Member of the Institute of Environmental Management and Assessment (IEMA)*FIEMA - Fellow of the Institute of Environmental Management and Assessment (IEMA) === Environmental health ===* CPHI(C) – Certified Public Health Inspector (Canada)=== Explosive atmospheres ===IECEx covers the specialized field of explosion protection associated with the use of equipment in areas where flammable gases, liquids and combustible dusts may be present.", "This system provides the assurance that equipment is manufactured to meet safety standards, and that services such as installation, repair and overhaul also comply with IEC International Standards on 60079 series.", "The UNECE (United Nations Economic Commission for Europe), cited IECEx as one example of a practice model for the verification of conformity to IEC Standards, for European smaller countries with no certification schemes for such equipment.", "It published a \"Common Regulatory Framework\" as a suggestion for those countries implementing a certification program for the explosive atmospheres' segment.=== Fiber optics and data cabling ===* RCDD (Registered Communications Distribution Designer) by BICSI* DCI (Data Cabling Installer) conferred by Electronics Technicians Association* FOI (Fiber Optics Installer) conferred by Electronics Technicians Association* FOT (Fiber Optics Technician) conferred by Electronics Technicians Association* FOT-OSP (Fiber Optics Technician-Outside Plant) conferred by Electronics Technicians Association* FOD (Fiber Optics Designer) conferred by Electronics Technicians Association* TTT (Termination and Testing Technician) conferred by Electronics Technicians Association=== Geology ===* EurGeol (European Geologist) conferred by the European Federation of Geologists (EFG).", "* PGeo (Professional Geologist) conferred by the American Institute of Professional Geologists (AIPG).=== Genealogy ===* AG (Accredited Genealogist) conferred by the International Commission for the Accreditation of Professional Genealogists (ICAPGen).", "* CG (Certified Genealogist) conferred by the Board for Certification of Genealogists (BCG).", "* CGL (Certified Genealogical Lecturer) conferred by the Board for Certification of Genealogists (BCG).=== Health leadership ===* CHE (Certified Health Executive) conferred by the Canadian College of Health Leaders (CCHL)=== Human Resources ===* aPHR (Associate Professional in Human Resources) conferred by the Human Resources Certification Institute* PHR (Professional in Human Resources) conferred by the Human Resources Certification Institute*SPHR (Senior Professional in Human Resources) conferred by the Human Resources Certification Institute*SHRM-CP (Society for Human Resources Management – Certified Professional) conferred by the Society for Human Resources Management*SHRM-SCP (Society for Human Resources Management – Senior Certified Professional) conferred by the Society for Human Resources Management=== Hospitality and tourism ===* CHA (Certified Hotel Administrator) conferred by American Hotel & Lodging Association* CMP (Certified Meeting Professional) conferred by Convention Industry Council* CEM (Certified in Exhibition Management) conferred by International Association of Exhibitions and Events=== Insurance and risk management ===In the United States, insurance professionals are licensed separately by each state.", "Many individuals seek one or more certifications to distinguish themselves from their peers.", "* American College of Financial Services:** Chartered Life Underwriter (CLU)** Chartered Financial Consultant (ChFC)* American Institute For Chartered Property Casualty Underwriters (The Institutes):** Chartered Property Casualty Underwriter (CPCU®)** Associate in Risk Management (ARM)* National Alliance for Insurance Education & Research administers the Certified Insurance Counselor (CIC)* Professional Liability Underwriting Society (PLUS) administers Registered Professional Liability Underwriter (RPLU).", "* American Educational Institute (AEI)** Accredited Claims Adjuster\t(ACA)** Accredited Claims Professional\t(ACP)** Accredited Claims Professional Candidate\t(ACAc)** Associate in Claims\t(AIC)** Applied Microbial Remediation Technician\tAMRC** Casualty General Adjuster\t(CGA)** Certified Claims Adjuster\t(CCA)** Certified Claims Professional\t(CCP)** Certified Claims Professional Candidate\t(CCPc)** Chartered Property Casualty Underwriter candidate\t(CPCUc)** Certied Forensic Litigation Consultant\t(CFLC)** Certified General Adjuster\t(CrtGA)** Certified Mold Specialist\t(CMS)** Certified Mold Inspector\t(CMI)** Certified Property Appraiser and Umpire\t(CPAU)** Certified Property Loss Appraiser\t(CPLA)** Certified Property Loss Umpire\t(CPLU)** Casualty General Adjuster\t(CGA)** Certified General Adjuster\t(CrtGA)** Casualty General Adjuster\t(CGA)** Executive General Adjuster\t(EGA)** Fire & Smoke Restoration Technician\t(FSRT)** GrandMaster General Adjuster\t(GMGA)** HAAG Engineering Certified Roofing Inspector Residential/Commercial\t(HCI-R/C)** Insurance Claims Expert\t(ICE)** Legal Principles Claims Specialist\t(LPCS)** Master General Adjuster\t(MGA)** Master Public Adjuster\t(MPA)** Property Claims Law Associate\t(PCLA)** Property General Adjuster\t(PGA)** Registered General Adjuster\t(RGA)** Senior Professional Public Adjuster (SPPA)** Universal Claims Certification\t(UCC)** Windstorm Insurance Network Professional\t(WIND-P)** Water Remediaton Technician\t(WRT)=== Language education ===TESOL is a large field of employment with widely varying degrees of regulation.", "Most provision worldwide is through the state school system of each individual country, and as such, the instructors tend to be trained primary- or secondary school teachers who are native speakers of the language of their pupils, and not of English.", "Though native speakers of English have been working in non-English speaking countries in this capacity for years, it was not until the last twenty-five years or so that there was any widespread focus on training particularly for this field.", "Previously, workers in this sort of job were people engaging in backpacker tourism hoping to earn some extra travel money or well-educated professionals in other fields volunteering, or retired people.", "These sort of people are certainly still to be found, but there are many who consider TESOL their main profession.One of the problems facing these full-time teachers is the absence of an international governing body for the certification or licensure of English language teachers.", "However, Cambridge University and its subsidiary body UCLES are pioneers in trying to get some degree of accountability and quality control to consumers of English courses, through their CELTA and DELTA programs.", "Trinity College London has equivalent programs, the CertTESOL and the LTCL DipTESOL.", "They offer initial certificates in teaching, in which candidates are trained in language awareness and classroom techniques, and given a chance to practice teaching, after which feedback is reported.", "Both institutions have as a follow-up a professional diploma, usually taken after a year or two in the field.", "Although the initial certificate is available to anyone with a high school education, the diploma is meant to be a post-graduate qualification and can in fact be incorporated into a master's degree program.=== Legal affairs ===An increasing number of attorneys are choosing to be recognized as having special expertise in certain fields of law.", "According to the American Bar Association, a lawyer who is a certified specialist has been recognized by an independent professional certifying organization as having an enhanced level of skill and expertise, as well as substantial involvement in an established legal specialty.", "These organizations require a lawyer to demonstrate special training, experience and knowledge to ensure that the lawyer's recognition is meaningful and reliable.", "Lawyer conduct with regard to specialty certification is regulated by the states.Legal administrators vary in their day-to-day responsibilities and job requirements.", "The Association of Legal Administrators (ALA) is the credentialing body of the Certified Legal Manager (CLM) certification program.", "CLMs are recognized as administrators who have passed a comprehensive examination and have met other eligibility requirements.", ":=== Librarians ===In Australia, ALIA (Australian Library and Information Association) certifies librarians and library technicians.", "Distinguished librarians who have completed a high level of professional learning are awarded the Distinguished Certified Professional Award.", "Prior to 2013, this award was known as Associate Fellows.In New Zealand, the accrediting body is LIANZA (Library and Information Association of New Zealand Aotearoa Te Rau Herenga O Aotearoa).", "LIANZA accredit prominent librarians at three levels, Fellows, Life Members and Associates.=== Logistics and transport ===Logistician is the profession in the logistics and transport sectors, including sea, air, land and rail modes.", "Professional qualification for logisticians usually carries post-nominal letters.Certification granting bodies include, but are not limited to, Institute for Supply Management (ISM), Association for Operations Management (APICS), Chartered Institute of Logistics and Transport (CILT), International Society of Logistics (SOLE), Canadian Institute of Traffic and Transportation (CITT), and Allied Council for Commerce and Logistics (ACCL).=== Management Consulting ===Management consulting is the practice of providing consulting services to organizations to improve their performance or in any way to assist in achieving any sort of organizational objectives.The profession's primary certification is the \"Certified Management Consultant\" (CMC) designation.Certification granting bodies are the approximately 50 Institutes of Management Consulting belonging to the International Council of Management Consulting Institutes (ICMCI).", "=== Marketing ===* CDMP (Certified Digital Marketing Professional), conferred by Digital Marketing Institute.", "* CME (Certified Marketing Executive), conferred by Sales & Marketing Executives International, Inc..* CyQUal (Cyber qualification), The Digital Degree Accredited certification offered by FreeUniversityOnline.com* Social Media Marketing Certification, Digital Marketing Master Certification, SEO Certification, conferred by Boot Camp Digital=== Ministers ===Churches have their own process of who may use various religious titles.", "Protestant churches typically require a Masters of Divinity, accreditation by the denomination and ordination by the local church in order for a minister to become a \"Reverend\".", "Those qualifications may or may not also give government authorization to solemnize marriages.=== Medicine ===Board certification is the process by which a physician in the United States documents by written, practical or computer based testing, illustrating a mastery of knowledge and skills that define a particular area of medical specialization.", "The American Board of Medical Specialties, a not-for-profit organization, assists 24 approved medical specialty boards in the development and use of standards in the ongoing evaluation and certification of physicians.Medical specialty certification in the United States is a voluntary process.", "While medical licensure sets the minimum competency requirements to diagnose and treat patients, it is not specialty specific.", "Board certification demonstrates a physician's exceptional expertise in a particular specialty or sub-specialty of medical practice.Patients, physicians, health care providers, insurers and quality organizations regard certification as an important measure of a physician's knowledge, experience and skills to provide quality health care within a given specialty.Other professional certifications include certifications such as medical licenses, Membership of the Royal College of Physicians, Fellowship of the Royal College of Physicians and Surgeons of Canada, nursing board certification, diplomas in social work.", "The Commission for Certification in Geriatric Pharmacy certifies pharmacists that are knowledgeable about principles of geriatric pharmacotherapy and the provision of pharmaceutical care to the elderly.", "Additional certifying bodies relating to the medical field include:* Royal Australian and New Zealand College of Radiologists* American College of Emergency Physicians* Royal Australasian College of Physicians* Fellowship of the Royal College of Surgeons* Membership of the College of Emergency Medicine* Joint Commission on Allied Health Personnel in Ophthalmology* American Registry for Diagnostic Medical Sonography=== Medical coding and billing ===* AHIMA (American Health Information Management Association)* AAPC* Medical Association of Billers=== Peer support ===NCPRP stands for \"National Certified Peer Recovery Professional\", and the NCPRP credential and exam were developed in collaboration with the International Certification Board of Recovery Professionals (ICBRP) and is currently being administered by PARfessionals.PARfessionals is a professional organization and all of the available courses are professional development and pre-certification courses.The NCPRP credential and exam focus primarily on the concept of peer recovery through mental health and addiction recovery.", "It has the main purpose of training student-candidates on how to become peer recovery professionals who can provide guidance, knowledge or assistance for individuals who have had similar experiences.Each student-candidate must complete several key steps which include initial registration; the pre-certification review course; and all applicable sections of the official application in order to become eligible to complete the final step, which is the NCPRP certification exam.The NCPRP credential is obtained once a participant successfully passes the NCPRP certification exam by the second attempt and is valid for five years.=== Physical asset management ===* CMRP – Certified Maintenance and Reliability Professional (CMRP)* MMP – Maintenance Management Professional=== Pilates ===* PMA(R) CPT=== Plumbing ===* ASSE (American Society of Sanitary Engineering) – an ANSI Accredited standards developer and certification body=== Project management ===Organizations that offer various certifications include:* American Academy of Project Management* Project Management Institute* Stanford University through the Stanford Advanced Project Management Certificate Program* CPMA (Certified Project Management Analyst) conferred by IQN* Association for Project Management* IPMA (International Project Management Association)* Commercial Project Manager through Commercial Officers Group=== Public health ===National Board of Public Health Examiners, www.nbphe.org=== Public relations ===In the US, the Universal Accreditation Board, an organization composed of the Public Relations Society of America, the Agricultural Relations Council, the National School Public Relations Association, the Religious Communicators Council and other public relations professional societies, administers the Accreditation in Public Relations (APR), a voluntary certification program for public relations practitioners.=== Public Participation ===The Certified Public Participation Professional (CP3) and Master Certified Public Participation Professional (MCP3) are awarded by two regions of the International Association for Public Participation (IAP2) : IAP2 Canada and IAP2 USA.", "As of 2019, only 25 individuals had achieved either of these distinctions.", "The CP3 designation is awarded upon successfully completing a three-step process that includes a written application documenting the individual's experience in the profession, a written response to a case study, and an in-person oral assessment.Individuals seeking certification are assessed against 5 Core Competencies, which are the essential capabilities for a professional in this field to effectively design, implement, and evaluate public participation programs.", "The competencies emerged from qualitative analysis of a comprehensive list of knowledge, attitudes, beliefs, skills, behaviors, and capabilities identified in June 2014 by more than 100 P2 professionals from around the world.", "The descriptions and quality standards for each competency were developed, tested, and refined through an iterative process involving IAP2 members.", "Each competency is further divided into individual criteria.", "An individual must meet or exceed every criterion to achieve the CP3 designation.", "IAP2 USA's program includes 29 criteria.", "IAP2 Canada's program includes 31 criteria; the two additional criteria in Canada address federal requirements for indigenous engagement.", "The MCP3 designation recognizes additional specialization and expertise and is assessed through a written application available only to individuals who have already achieved the CP3 designation.To maintain professional certification, individuals must maintain active membership in IAP2, provide a minimum of 20 hours (annually) of volunteer (unpaid) service to IAP2, and participate in a minimum of 12 hours (annually) of continued professional development.===Real estate management===The Building Owners and Managers Association and the International Facility Management Association offer professional certifications for the operation and management of commercial properties.=== Renewable energy ===* PVIP (PV Installation Professional) conferred by North American Board of Certified Energy Practitioners* PVDS (PV Design Specialist) conferred by North American Board of Certified Energy Practitioners* PVIS (PV Installation Specialist) conferred by North American Board of Certified Energy Practitioners* PVCMS (PV Commissioning & Maintenance Specialist) conferred by North American Board of Certified Energy Practitioners* PVSI (PV System Inspector) conferred by North American Board of Certified Energy Practitioners* PVTS (PV Technical Sales) conferred by North American Board of Certified Energy Practitioners* SHI (Solar Heating Installer) conferred by North American Board of Certified Energy Practitioners* SHSI (Solar Heating System Inspector conferred by North American Board of Certified Energy Practitioners* EVT (Electronic Vehicle Technician) conferred by Electronics Technicians Association* PVI (Photovoltaic Installer) conferred by Electronics Technicians Association* SWI (Small Wind Installer) conferred by Electronics Technicians Association===Safety and Occupational Hygiene===* Certified Safety Professional offered by the Board of Certified Safety Professionals* Certified Industrial Hygienist* Certified Safety Specialist=== Sales ===Organizations offering certification include:* Sales & Marketing Executives International* Canadian Professional Sales Association=== Security ===* ASIS International administers the Certified Protection Professional – Board-Certified in Security Management (CPP)* ASIS International administers the Physical Security Professional, Board-Certified (PSP)* ASIS International administers the Professional Certified Investigator, Board-Certified (PCI)* Association of Certified Fraud Examiners administers the Certified Fraud Examiner (CFE)* International Foundation of Protection Officers administers the Certified Protection Officer (CPO)* Society of Payment Security Professionals (SPSP) administers the Certified Payment-Card Industry Security Manager* National Protective Services (www.npsorg.com) administers the Certified Protection Executive (CPE) professional certification >" ], [ "Other applications", "* The American Academy of Environmental Engineers board certifies licensed environmental engineers (Board Certified Environmental Engineer—BCEE) and unlicensed environmental engineering practitioners (Board Certified Environmental Engineering Member—BCEEM) for those with a degree in engineering and at least 8 years of practice and responsible charge in environmental engineering.", "* The American Institute of Floral Designers offers two levels of certification for individuals in the field of professional floral design.", "Certified Floral Designer (CFD) and accredited membership (AIFD) are both designed to establish a gold standard in professional floral design while ensuring the certified individual maintains that standard through continued education credits.", "While many state-level floral associations also offer state-level floral design certification known as Master Florist certification, AIFD certification is the highest level of professional floral design awarded in the United States.", "* The Canadian National Association of Infrared Imaging Technologists (AIIT) awards the IIT designation to infrared thermographers who meet the training standards regulated by the association.", "AIIT aims to ensure service delivery standards and public trust through regulating training standards, codes of conduct and continuing education.", "* The Society for Technical Communication (STC) is planning to create a certification program for technical writers in 2011.", "* The International Society of Arboriculture (ISA) is the International body who administers ANSI-accredited certification programs for arborists and tree care specialists.", "Certifications vary from Tree Worker to Certified Arborist to Master Arborist." ], [ "Criticisms", "Political commentators have criticized professional or occupational licensing, especially medical and legal licensing, for restricting the supply of services and therefore making them more expensive, often putting them out of reach of the poor.The proliferation of IT certifications (both offered and attained) has led some technologists to question their value.", "Proprietary content that has been distributed on the Internet allows some to gain credentials without the implied depth or breadth of expertise." ], [ "See also", "* Academic inflation* European professional qualification directives* Homologation* Institute for Certification of Computing Professionals* Product certification* Vocational Competence Certificate" ], [ "References" ] ]
wikipedia
[ [ "Carl Menger" ], [ "Introduction", "'''Carl Menger von Wolfensgrün''' (; ; 28 February 1840 – 26 February 1921) was an Austrian economist and the founder of the Austrian School of economics.", "Menger contributed to the development of the theories of marginalism and marginal utility, which rejected cost-of-production theory of value, such as developed by the classical economists such as Adam Smith and David Ricardo.", "As a departure from such, he would go on to call his resultant perspective, the subjective theory of value." ], [ "Biography", "=== Family and education ===Carl Menger von Wolfensgrün was born in the city of Neu-Sandez in Galicia, Austrian Empire, which is now Nowy Sącz in Poland.", "He was the son of a wealthy family of minor nobility; his father, Anton Menger, was a lawyer.", "His mother, Caroline Gerżabek, was the daughter of a wealthy Bohemian merchant.", "He had two brothers, Anton and Max, both prominent as lawyers.", "His son, Karl Menger, was a mathematician who taught for many years at Illinois Institute of Technology.After attending ''gymnasium'' he studied law at the Universities of Prague and Vienna and later received a doctorate in jurisprudence from the Jagiellonian University in Kraków.", "In the 1860s Menger left school and enjoyed a stint as a journalist reporting and analyzing market news, first at the ''Lemberger Zeitung'' in Lemberg, Austrian Galicia (now Lviv, Ukraine) and later at the in Vienna.=== Career ===During the course of his newspaper work, he noticed a discrepancy between what the classical economics he was taught in school said about price determination and what real world market participants believed.", "In 1867 Menger began a study of political economy which culminated in 1871 with the publication of his ''Principles of Economics'' ''(''''),'' thus becoming the father of the Austrian School of economic thought.", "It was in this work that he challenged classical cost-based theories of value with his theory of marginality – that price is determined at the margin.In 1872 Menger was enrolled into the law faculty at the University of Vienna and spent the next several years teaching finance and political economy both in seminars and lectures to a growing number of students.", "In 1873, he received the university's chair of economic theory at the very young age of 33.In 1876 Menger began tutoring Archduke Rudolf von Habsburg, the Crown Prince of Austria in political economy and statistics.", "For two years, Menger accompanied the prince during his travels, first through continental Europe and then later through the British Isles.", "He is also thought to have assisted the crown prince in the composition of a pamphlet, published anonymously in 1878, which was highly critical of the higher Austrian aristocracy.", "His association with the prince would last until Rudolf's suicide in 1889.In 1878 Rudolf's father, Emperor Franz Joseph, appointed Menger to the chair of political economy at Vienna.", "The title of ''Hofrat'' was conferred on him, and he was appointed to the Austrian in 1900.==== Dispute with the historical school ====Ensconced in his professorship, he set about refining and defending the positions he took and methods he utilized in ''Principles,'' the result of which was the 1883 publication of ''Investigations into the Method of the Social Sciences with Special Reference to Economics ('''').''", "The book caused a firestorm of debate, during which members of the historical school of economics began to derisively call Menger and his students the \"Austrian School\" to emphasize their departure from mainstream German economic thought – the term was specifically used in an unfavorable review by Gustav von Schmoller.In 1884 Menger responded with the pamphlet ''The Errors of Historicism in German Economics'' and launched the infamous '','' or methodological debate, between the Historical School and the Austrian School.", "During this time Menger began to attract like-minded disciples who would go on to make their own mark on the field of economics, most notably Eugen von Böhm-Bawerk, and Friedrich von Wieser.In the late 1880s, Menger was appointed to head a commission to reform the Austrian monetary system.", "Over the course of the next decade, he authored a plethora of articles which would revolutionize monetary theory, including \"The Theory of Capital\" (1888) and \"Money\" (1892).", "Largely due to his pessimism about the state of German scholarship, Menger resigned his professorship in 1903 to concentrate on study." ], [ "Philosophical influences", "There are different opinions on Menger's philosophical influences.", "But it is without discussion that there is a rudimentary dispute of Menger with Plato and a very meticulous one with Aristotle, especially with his ethics.", "\"Plato holds that money is an agreed sign for change and Aristotle says, that money came into being as an agreement, not by nature, but by law.", "\"Also, the influence of Kant is provable.", "Many authors emphasize also rationalism and idealism, as is represented by Christian Wolff.", "Looking at the literature, most writers think that Menger represents an essential Aristotelian position.", "This is surprisingly a position that is contrary to his theory of the subjective value and his individualistic methodological position.Another entry is the use of deduction or induction.", "With his price theory can be shown that Menger is nominalistic and, stronger, anti-essentialistic.", "That is to say that his approach is inductionalistic." ], [ "Economics", "'''', 1933Menger used his subjective theory of value to arrive at what he considered one of the most powerful insights in economics: \"both sides gain from exchange\".", "Unlike William Jevons, Menger did not believe that goods provide \"utils,\" or units of utility.", "Rather, he wrote, goods are valuable because they serve various uses whose importance differs.", "Menger also came up with an explanation of how money develops that is still accepted by some schools of thought today.=== Money ===Menger believed that gold and silver were the precious metals that were adopted as money for their unique attributes like costliness, durability, and easy preservation, making them the \"most popular vehicle for hoarding as well as the goods most highly favoured in commerce.\"", "Menger showed that \"their special saleableness\" tended to make their bid-ask spread tighter than any other market good, which led to their adoption as a general medium of exchange and evolution in many societies as money." ], [ "Works", "* 1871 – ; Translated as * 1883 – ; Translated as * 1884 – ''The Errors of Historicism in German Economics''* 1888 – ''The Theory of Capital''* 1892 –" ], [ "See also", "* Methodenstreit* History of macroeconomic thought*Historical school of economics" ], [ "References" ], [ "Further reading", "* * Ebeling, Richard M., \"Carl Menger and the Sesquicentennial Founding of the Austrian School,\" American Institute for Economic Research, January 5, 2021* Ebeling, Richard M., \"Carl Menger's Theory of Institutions and Market Processes,\" American Institute for Economic Research, April 13, 2021** * * * * ** * von Wieser, Friedrich, \"Carl Menger: A Biographical Appreciation\" 1923, American Institute for Economic Research, February 25, 2019" ], [ "External links", "** The Epistemological Import of Carl Menger's Theory of the Origin of Money Ludwig von Mises in ''Human Action'' on Menger's Theory of the Origins of Money* Profile on Carl Menger at the History of Economic Thought Website* Principles of Economics , online version provided by the Ludwig von Mises Institute.", "* ''Grundsätze der Volkswirtschaftslehre'' (''Principles of Economics'')* Principles of Economics (PDF Spanish)* On the Origin of Money (English Translation), online version provided by the Monadnock Press* Carl Menger Papers, 1857–1985, Rubenstein Library, Duke University*" ] ]
wikipedia
[ [ "List of cartoonists" ], [ "Introduction", "This is a '''list of cartoonists''', visual artists who specialize in drawing cartoons.", "This list includes only notable cartoonists and is not meant to be exhaustive.", "Note that the word 'cartoon' only took on its modern sense after its use in Punch magazine in the 1840s - artists working earlier than that are more correctly termed 'caricaturists'," ], [ "Notable cartoonists", "* Scott Adams, ''Dilbert''* Charles Addams (1938-1988), macabre cartoons featured in ''The New Yorker'' and elsewhere* Attila Adorjany* Sarah Andersen, known for ''Sarah's Scribbles''* Barry Appleby* Sergio Aragonés, known for his contributions to ''Mad''* Graciela Aranis (1908-1996), Chilean painter, cartoonist* Arotxa (Rodolfo Arotxarena)* Jim Bamber, cartoonist of ''Autosport'', magazine specialising in motor sports* Edgar Henry Banger* Carl Barks, inventor of ''Duckburg'' and many of its characters like ''Scrooge McDuck'' and ''Gladstone Gander''; Fantagraphics Books called him \"the Hans Christian Andersen of comic books.", "\"* Sumanta Baruah* Aminollah Rezaei* Niko Barun* Nancy Beiman, \"FurBabies\"* Darrin Bell, ''Candorville'' and ''Rudy Park''* Steve Bell, ''The Guardian'' (UK)* Stephen Bentley, \"Herb and Jamaal\"* Oscar Berger, ''Aesop's Foibles (1947)''; active 1920s–1960s* Mark Beyer, ''Amy and Jordan'', ''Agony''* Brumsic Brandon Jr., \"Luther\"; with his daughter Barbara Brandon-Croft, first family of cartoonists (father/daughter) to each be nationally syndicated in the U.S. mainstream press* Barbara Brandon-Croft, \"Where I'm Coming From\"; first Black woman cartoonist to be nationally syndicated in the U.S. mainstream press* Berkeley Breathed, ''Bloom County'' and ''Outland''* Frédéric-Antonin Breysse* Ed Brubaker* Henry Bunbury 18th Century British caricaturist* Tom Bunk, cartoonist for ''Mad''* Stanley Burnside, ''Sideburns''* Mark Burrier* John Byrne* Al Capp, ''Li'l Abner''* Tom Cheney, staff cartoonist for ''The New Yorker''* Edgar Church* Chester Commodore, political cartoonist* George Cruikshank 19th Century British caricaturist* Isaac Cruikshank 18th Century British caricaturist* Isaac Robert Cruikshank 19th Century British caricaturist* Robert Crumb, ''Mr.", "Natural'', ''Fritz the Cat'', ''Keep on Truckin'''* Natalie d'Arbeloff* Jack Davis* Jim Davis, ''Garfield''* Abner Dean* Arifur Rahman* Narayan Debnath, Indian cartoonist known for ''Handa Bhonda'', ''Bantul the Great'', and ''Nonte Phonte''* Richard Decker, ''The New Yorker''* Walt Disney, ''Mickey Mouse'', ''Donald Duck''* Ralph Waddell Douglass* Stan Drake* George du Maurier, also the author of Trilby* Robert W. Edgren, American political cartoonist known for his \"Sketches from Death\" from the Spanish–American War* Will Eisner, ''The Spirit''* Otto Eppers* Charles Evenden* Lyonel Feininger, rare fine artist who did strips, ''The Kin-der-Kids'' and ''Wee Willie Winkie's World''* Rod Filbrandt* David Fletcher* Ellen Forney* André François* André Franquin, ''Spirou et Fantasio'', ''Gaston Lagaffe'', ''Marsupilami''* Yuliy Abramovich Ganf, Soviet Russian* Eddie Germano* Denis Gifford, strips in ''Whizzer and Chips'', ''Knockout'', ''Marvelman''* Carl Giles* James Gillray, 18th century British, called \"the father of the political cartoon\".", "* John Glashan, ''Genius''* Rube Goldberg, cartoons of complex and convoluted machines doing very simple tasks.", "* Larry Gonick, ''The Cartoon History of the Universe series, Kokopelli & Company''* Cleven \"Goodie\" Goudeau, known for his pioneering Afrocentric images on greeting cards* Jimmy Gownley, ''Amelia Rules!", "series, Simon & Schuster''* Bud Grace, \"Ernie/Piranha Club\"* Mel Graff, “The Adventures of Patsy”, “Secret Agent X-9”* Matt Groening, ''Life in Hell'', ''The Simpsons'', ''Futurama''* Sam Gross, for his ''The New Yorker'' work, plus many other magazines* Shekhar Gurera, well known for his quirky cartoons about India's political and social trends* William Haefeli* Martin Handford, ''Where's Wally?", "''* Steven Harris* Butch Hartman, ''The Fairly OddParents'', ''T.U.F.F.", "Puppy'', ''Danny Phantom'', ''Bunsen Is a Beast''* Andrew Kennaway Henderson* Henfil, Brazilian cartoonist* Hergé, ''The Adventures of Tintin''* George Herriman, ''Krazy Kat''* Herblock American cartoonist* Watson Heston* Stephen Hillenburg (1961-2018), ''SpongeBob SquarePants''* Bill Hinds, \"Tank McNamara\"* Dick Hodgins, Jr.* William Hogarth, English pictorial satirist and editorial cartoonist; credited with pioneering western sequential art; work ranged from realistic portraiture to comic strip* Bill Holbrook, ''On the Fastrack'', ''Safe Havens'', and ''Kevin and Kell''* Nicole Hollander, ''Sylvia''* John Holmstrom* Geoff \"Jeff\" Hook, Australian* George William Houghton, British golf cartoonist* Jim Hummel* Edgar Pierre Jacobs, ''Blake and Mortimer''* Al Jaffee, ''Mad''* Kirk Jarvinen* S. Jithesh, World's Fastest Performing Cartoonist* Herbert Johnson* Mike Judge, ''Beavis and Butt-head'', ''King of the Hill'', ''The Goode Family''* Arja Kajermo* Avi Katz* Bil Keane, \"Family Circus\"* Jeff Keane.", "\"Family Circus\"* Walt Kelly, ''Pogo''* Rik Kemp* Molly Kiely* Wyncie King* Jeff Kinney, ''Diary of a Wimpy Kid''* Rick Kirkman, \"Baby Blues\"* Heinrich Kley* B. Kliban* John Kricfalusi, ''The Ren & Stimpy Show''* Gary Larson, ''The Far Side''* Rick Law, ''Beyond the Veil''* R K Laxman, cartoonist for ''The Times of India'', India* Mell Lazarus.", "\"Momma, Miss Peach\"* John Leech, 19th-century ''Punch'' cartoonist* Jonathan Lemon, ''Alley Oop''* Michael Leunig, Australian* Arnold Levin* David Liljemark* Neil Lonsdale (1907-1989), New Zealand editorial cartoonist* David Low, New Zealand political cartoonist and caricaturist* Jay Lynch* Trey Parker and Matt Stone, ''South Park''* Seth MacFarlane, ''Family Guy'', ''American Dad!", "'', ''The Cleveland Show''* Manjul, ''India Today'', ''The Economic Times'' and ''Daily News and Analysis''* Bob Mankoff, ''The New Yorker''* Jack Markow* Enrico Mazzanti* Scott McCloud, ''Zot!", "'', ''Understanding Comics''* Aaron McGruder, ''The Boondocks''* Ronald Michaud* Yevgeniy Migunov* Mario Miranda, ''The Economic Times'', India* Shigeru Mizuki, ''Ge Ge Ge no Kitaro'', master of horror of Japanese manga* Guillermo Mordillo* Lorin Morgan-Richards* Morris, ''Lucky Luke''* Joe Murray, ''Rocko's Modern Life'' and ''Camp Lazlo!", "''* Rachel Nabors* Ogden Nash* Nigar Nazar, first female cartoonist of the Muslim world, creator of cartoon character \"Gogi\"* Roy Nelson* Richard Newton, 18th century British caricaturist* Mana Neyestani, Iranian cartoonist* Ajit Ninan, ''India Today'' and ''The Times of India''* Floyd Norman* Murray Olderman, sports columnist, author of 14 books, National Cartoonist Society Sports Cartoon Award for 1974 and 1978* Jack Edward Oliver* Jackie Ormes, \"Torchy Brown in 'Dixie to Harlem\", \"Candy\", \"Patty-Jo 'n' Ginger\", \"Torchy in 'Hearbeats'\"; first Black woman cartoonist to be published nationally in the U.S. (not via syndication)* Bruce Ozella* Paul Palnik, American Jewish cartoonist* Gary Panter* Virgil Franklin Partch, known as \"VIP;\" leading American gag cartoonist from the 1940s to the 1980s* Alan Stuart Paterson, New Zealand cartoonist* Andrea Pazienza* René Pellos, French cartoonist* Bob Penuelas, ''Wilbur Kookmeyer''* Camillus Perera* Bruce Petty* Peyo, ''The Smurfs'', ''Steven Strong'', ''Johan and Peewit''* S. D. Phadnis, Indian cartoonist* Ziraldo Alves Pinto, Brazilian cartoonist* Hugo Pratt, ''Corto Maltese''* Ken Pyne* Quino (Joaquín Salvador Lavado), Argentine cartoonist and social satirist, known for ''Mafalda''* Jacki Randall* Roy Raymonde, 20th Century English cartoonist whose work appeared principally in Punch (magazine) and Playboy* Bob Rich, American award-winning cartoonist* W. Heath Robinson, British satirist known for drawings of convoluted machines, similar to Rube Goldberg* Christine Roche* Artie Romero* Ed \"Big Daddy\" Roth* Thomas Rowlandson 18th Century British caricaturist* Martin Rowson British political cartoonist* Øystein Runde* Malik Sajad Indian cartoonist, author of graphic novel ''Munnu - A Boy from Kashmir'''* Armando Salas* Gerald Scarfe ( political) * Jerry Scott, \"Baby Blues, Zits\" * Ronald Searle, St Trinians, Molesworth, ''The Rake's Progress'', editorial work* Elzie Crisler Segar, ''Popeye''* Sempé* Claude Serre* James Affleck Shepherd* Lee Sheppard* Gilbert Shelton* Mahmoud Shokraye* Shel Silverstein* Posy Simmonds, ''The Silent Three of St Botolph's'', ''Gemma Bovery''* Siné* Jeff Smith, ''Bone'', ''RASL'', ''Shazam!", ": The Monster Society of Evil'', ''Little Mouse Gets Ready''* Mauricio de Sousa, ''Monica's Gang'', ''Chuck Billy 'n' Folks'', ''The Cavern Clan''* Art Spiegelman, author of ''Maus''; co-editor of ''RAW'' magazine* Dan Spiegle* George Sprod, ''Punch'' and other publications* Ralph Steadman, editorial cartoonist and book illustrator* Ralph Stein* Saul Steinberg* Jay Stephens* Matt Stone, with Trey Parker, co-creator of ''South Park''* Jakob Martin Strid* Ed Subitzky, known for his ''National Lampoon'' work, also ''The New York Times''* Joost Swarte, Dutch comic artist known for his ligne claire or clear line style of drawing* Betty Swords* Les Tanner, political cartoonist* Howard Tayler, pioneered web-cartooning as a profession* Raina Telgemeier* Osamu Tezuka, ''Astro Boy'', ''Phoenix''; known as the \"God\" of Japanese manga who defined modern Japanese cartooning* Bal Thackeray, formed a political party in India* Lefred Thouron* Morrie Turner, credited with the first multicultural syndicated cartoon strip* Albert Uderzo, ''Asterix''* Jim Unger, Canadian cartoonist: ''Herman''* Willy Vandersteen, ''Spike and Suzy'', ''De Rode Ridder''* Joan Vizcarra* Vicco von Bülow, ''Loriot''* Keith Waite, New Zealand-born English editorial cartoonist* Mort Walker, ''Beetle Bailey'', ''Hi and Lois''* Arthur Watts* Ben Wicks, Canadian cartoonist and illustrator: ''The Outsider'', ''Wicks''* S. Clay Wilson, ''Zap Comix'', ''Underground Comix''* Shannon Wright* Rhie Won-bok* Bianca Xunise, \"Six Chix\"; first nonbinary cartoonist to be nationally syndicated in the U.S. mainstream press* Art Young* José Zabala-Santos* Zapiro" ], [ "Cartoonists of comic strips", "* Scott Adams, ''Dilbert''* Alex Akerbladh* Bill Amend, ''FoxTrot''* George Baker, ''Sad Sack''* Tom Batiuk, ''Funky Winkerbean''* Murray Ball, ''Footrot Flats''* Darrin Bell, ''Candorville'', ''Rudy Park''* Stephen Bentley, \"Herb and Jamaal\"* Jerry Bittle* Boulet, pseudonym of French cartoonist Gilles Roussel* Brumsic Brandon Jr., \"Luther\"* Barbara Brandon-Croft, \"Where I'm Coming From\"* Berkeley Breathed, ''Bloom County'' (1980s American social-political), ''Outland'', ''Opus''* Dave Breger, ''Mister Breger''* Dik Browne, ''Hi and Lois'', ''Hägar the Horrible''* Ernie Bushmiller, ''Nancy''* Milton Caniff, ''Terry and the Pirates'', ''Steve Canyon''* Al Capp, ''Li'l Abner''* Ad Carter, ''Just Kids''* Jok Church, ''You Can With Beakman and Jax''* Francis Cleetus, ''It's Geek 2 Me''* Mitch Clem, ''Nothing Nice to Say'', ''San Antonio Rock City''* Darby Conley, ''Get Fuzzy''* Joan Cornellà* Dave Coverly, ''Speed Bump''* Max Crivello* Alex Raymond, ''Flash Gordon'', ''Jungle Jim'', ''Rip Kirby''* Stan Cross, ''The Potts''* Stacy Curtis, ''Cul de Sac''* Lyman Dally, ''Max Rep''* Harry Grant Dart* Lou Darvas* Jim Davis, ''Gnorm Gnat'', ''Garfield'', ''U.S.", "Acres'', a ''Mr.", "Potato Head'' comic strip* Reginald Ben Davis* Derf Backderf (John Backderf)* Brad Diller* J. C. Duffy, ''The Fusco Brothers''* Edwina Dumm* Frank Dunne* Benita Epstein, ''Six Chix''* Larry Feign, ''The World of Lily Wong''* Norm Feuti, ''Retail''* George Fett, ''Sniffy and Norbert''* Charles Fincher, creator of ''Thadeus & Weez'' and ''The Daily Scribble''* Bud Fisher, ''Mutt and Jeff''* Ham Fisher, ''Joe Palooka''* Evelyn Flinders, ''The Silent Three''* Harold Rudolf Foster, ''Prince Valiant'' and ''Tarzan''* J.D.", "Frazer, ''User Friendly''* David Füleki, ''78 Tage auf der Straße des Hasses''* Paul Gilligan, ''Pooch Cafe''* Erich von Götha de la Rosière* Chester Gould, ''Dick Tracy''* Bud Grace, \"Ernie/Piranha Club\", \"Babs and Aldo\"* Mel Graff, “The Adventures of Patsy”, “Secret Agent X-9”* Bill Griffith, ''Zippy the Pinhead''* Cathy Guisewite, ''Cathy''* Nicholas Gurewitch, ''Perry Bible Fellowship''* Alex Hallatt* Johnny Hart, ''B.C.", "'', ''The Wizard of Id''* Bill Hinds, ''Tank McNamara'', ''Cleats'', ''Buzz Beamer''* Bill Holman, ''Smokey Stover''* Daniel Hulet* Billy Ireland* Tatsuya Ishida, ''Sinfest''* Tove and Lars Jansson, ''The Moomins''* Ferd Johnson, ''Moon Mullins''* Kerry G. Johnson, ''Harambee Hills'', caricaturist and children's book illustrator* Russell Johnson, ''Mister Oswald''* Lynn Johnston, ''For Better or For Worse''* Eric Jolliffe, ''Andy''* Bil Keane, ''Family Circus''* Jeff Keane, ''Family Circus''* Walt Kelly, ''Pogo''* James Kemsley, ''Ginger Meggs''* Hank Ketcham, ''Dennis the Menace''* Kazu Kibuishi, ''Copper''* Frank King, ''Gasoline Alley''* Rick Kirkman, \"Baby Blues\"* Keith Knight, ''The K Kronicles''* Charles Kuhn, ''Grandma''* Fred Lasswell, ''Barney Google''* Mell Lazarus, \"Momma, Miss Peach\"* Virginio Livraghi* Les Lumsdon, \"Basil\", \"Nipper\", \"Caspar\"* Edgar Martin* Clifford McBride, ''Napoleon''* Winsor McCay, ''Little Nemo''* Patrick McDonnell, ''Mutts''* Brian McFadden, ''Big Fat Whale''* Aaron McGruder, creator of the controversial strip ''The Boondocks''* George McManus, ''Bringing Up Father''* Caesar Meadows* Dale Messick, ''Brenda Starr''* Tim Molloy* Bill Murray, ''Sonny Boy''* Fred Negro, ''Pub Strip''* Chris Onstad, ''Achewood''* Jackie Ormes, \"Torchy Brown in 'Dixie to Harlem'\", \"Torchy in 'Heartbeats'\"* Phil Ortiz* Frode Øverli, ''Pondus''* Nina Paley, ''Nina's Adventures'', ''Fluff'', ''The Hots''* Brant Parker, ''The Wizard of Id''* Stephan Pastis, ''Pearls Before Swine''* Charles Peattie and Russell Taylor, ''Alex''* Mike Peters, ''Mother Goose & Grimm''* Keats Petree* Stan Pitt, ''Larry Flynn, Detective''* Vic Pratt* Dariush Ramezani* John Rivas, ''Bonzzo''* Valentina Romeo, ''Jonathan Steele'', ''Dylan Dog'', ''Morgan Lost'', ''Nathan Never''* Leigh Rubin, ''Rubes''* Warren Sattler, ''Grubby'', ''Billy the Kid'' and ''Yang'', as well as contributing artist for ''Barnaby'' daily, ''The Jackson Twins'', ''Bringing Up Father'' and ''Hi and Lois''* Charles M. Schulz, ''Peanuts'', ''Young Pillars''* Jerry Scott, \"Baby Blues, Zits, Nancy\" * Caroll Spinney, ''Harvey''* Lee W. Stanley, ''The Old Home Town''* Kris Straub, ''Starslip Crisis'', ''Checkerboard Nightmare''* Henry Matthew Talintyre* Harold Tamblyn-Watts* Russell Taylor and Charles Peattie, ''Alex''* Richard Thompson, ''Cul de Sac''* Jim Toomey, ''Sherman's Lagoon''* Harry J. Tuthill, ''The Bungle Family''* Gustave Verbeek, ''The Upside Downs'', ''The Terrors of the Tiny Tads''* Mort Walker, ''Beetle Bailey'', ''Hi and Lois''* Bill Watterson, ''Calvin and Hobbes''* Bob Weber, ''Moose & Molly''* Monty Wedd, ''Ned Kelly''* Alex Williams, ''Queen's Counsel''* Tom Wilson, ''Ziggy''" ], [ "Cartoonists of single-panel cartoons", "* Charles Addams* Gene Ahern* Glen Baxter* Belsky* Rupert Besley* Charles Boyce, ''Compu-Toon''* Barry Bradfield* Sheree Bradford-Lea* Bo Brown* Ivan Brunetti* John Callahan* Irwin Caplan* Patrick Chappatte (Chappatte)* Roz Chast* Chumy Chúmez* Mariza Dias Costa* Wilbur Dawbarn* Chon Day* Donelan* Denise Dorrance* Nick Downes* Mort Drucker* Vladimir Flórez* Stanley Arthur Franklin* Carl Giles (Giles), ''Daily Express''* Ted Goff* Bud Grace* Sam Gross* Dick Guindon* William Haefeli* Jessica Hagy* Baron Halpenny* Sidney Harris* William Haselden* Bill Hoest* Judy Horacek* Stan Hunt* Hank Ketcham* Ted Key* John F. Knott, creator of Old Man Texas, Dallas Morning News, 1905-1957 * Clyde Lamb* Gary Larson* Mel Lazarus* Robert Leighton* George Lichty* Mike Lynch* Lorin Morgan-Richards* Fred Neher* John Norment* Don Orehek* Jackie Ormes, \"Candy\", \"Patty-Jo 'n' Ginger\"* W. B.", "Park* Virgil Partch* Dave Pascal* Mad Peck* Matt Percival* Martin Perscheid* Josefina Tanganelli Plana* Gardner Rea* John Reiner* Dan Reynolds* Mischa Richter* Victoria Roberts* Burr Shafer* Vahan Shirvanian* Chris Slane* Grant Snider* Dan Steffan* James Thurber* Jerry Van Amerongen* H. T. Webster* Gluyas Williams* J. R. Williams, ''Out Our Way''* Gahan Wilson* George Wolfe* Kevin Woodcock* Bianca Xunise* Bill Yates* ZAK, pseudonym of Belgian cartoonist Jacques Moeraert* Zero" ], [ "Cartoonists of comic books", "* Carlo Ambrosini* Jack Herbert* Sergio Aragones, ''Mad''; creator of ''Groo''* Daniel A. Baker* Ken Battefield* Bill Benulis, ''War is Hell''* Steve Bialik* François Bourgeon, ''Le Cycle de Cyann''* Anna Brandoli* Reg Bunn* Ben Caldwell, creator of the Dare Detectives* Aldo Capitanio* Onofrio Catacchio* Domitille Collardey* Carlo Cossio, ''Dick Fulmine''* Jason Craig* Hugleikur Dagsson* Dame Darcy, creator of ''Meat Cake''* Patryck de Froidmont* Gianni De Luca, ''Commissario Spada''* Dan DeCarlo, ''Archie'', ''Josie and the Pussycats'', ''Sabrina, the Teenage Witch''* Kim Deitch creator of ''Waldo the Cat'' and comic novels* Vince Deporter, DC Comics; Nickelodeon, Spirou (Belgium)* Julie Doucet, creator of ''Dirty Plotte'', ''My New York Diary''* Will Elder, ''Mad'', ''Little Annie Fanny'' in ''Playboy''* Steve Fiorilla, mini-comics* Andy Fish* Brad W. Foster, creator of ''Mechthings'' mini-comics, ''The Mechthings'', ''Adventures of Olivia'' mini-comics* Chandra Free* Vernon Grant, creator of ''The Love Rangers''* Dick Hafer* Marc Hansen, creator of Ralph Snart* Los Bros Hernandez, creators of ''Love and Rockets''* Don Hillsman II* Yvonne Hutton* Al Jaffee, ''Mad'', ''Snappy Answers to Stupid Questions''* Robyn E. Kenealy* Helena Klakocar* Andrea Kruis* Harvey Kurtzman, founding editor of ''Mad''* Antonio Lara de Gavilán* Selena Lin* Craig McKay* Mark Marderosian* David Messer, adaptations of ''Macbeth'' and the ''Tempest''* Erika Moen* Colonel Moutarde* Art Nugent* Gaman Palem* Fung Chin Pang* Power Paola* Eduardo Vañó Pastor* Craig Phillips* Darren Sanchez* Seth, creator of ''Palookaville''* Ravi Shankar* Pran Kumar Sharma, ''Chacha Chaudhary''* Jeff Smith, ''Bone Book''* Cal Sobrepeña* Fermín Solís* Hans Steinbach* Kazimir Strzepek* Ramon Torrents* Przemysław Truściński* Jhonen Vasquez, ''Johnny the Homicidal Maniac'', ''Squee!", "'', ''I Feel Sick'', ''Everything Can be Beaten'', ''Fillerbunny'', ''Bad Art Collection'', ''Happy Noodle Boy''* Wally Wood, ''Mad''* Chao Yat* Carlos Zéfiro* Laura Zuccheri, ''Ken Parker'', ''Julia-le avventure di una criminologa''=== Cartoonists of action/superhero comic books ===* Kyle Baker, creator of ''Why I Hate Saturn''* Barry Bradfield, ''Batman: The Animated Homepage''* Greg Brooks* Jack Cole, creator of Plastic Man, later set the style for cartoons in ''Playboy''* Alan Davis, creator of ClanDestine* Steve Ditko, creator of many Marvel Comics, including Spider-Man and Doctor Strange, with editor Stan Lee* Will Eisner, creator of ''The Spirit'', teacher, publisher, one of the first to popularize the term ''graphic novel'', in his book ''A Contract with God''* Bob Kane, creator of The Batman with writer Bill Finger* Jack Kirby, creator of Captain America with his partner Joe Simon, and many other comics* Erik Larsen, creator of ''Savage Dragon''* Rob Liefeld, creator of ''Deadpool'' and ''Youngblood''* Jim McDermott* Todd McFarlane, creator of ''Spawn''* Shawn McManus* Mike Mignola, creator of ''Hellboy''* Frank Miller, creator of ''Sin City''* James O'Barr, creator of ''The Crow''* Paul Palnik, creator of ''The God of Cartoons''* Whilce Portacio* Humberto Ramos* Roberto Raviola, creator of ''La Compagnia della Forca''* Shelby Robertson* Alberto Saichann* Tim Sale* Horacio Sandoval* Marc Silvestri, creator of ''Cyberforce'' and ''The Darkness''* Dave Sim, creator of Cerebus* Jeff Smith, creator of ''Bone''* Ed Tourriol* Alain Voss" ], [ "See also", "* Editorial cartoons* Indian Institute of Cartoonists* List of American comics creators* List of animators* List of caricaturists* List of comic strips* List of editorial cartoonists* List of illustrators* List of manga artists* List of newspaper comic strips" ], [ "References" ] ]
wikipedia
[ [ "Civilization" ], [ "Introduction", "The ancient Sumerians of Mesopotamia were the oldest civilization in the world, beginning about 4000 BCE.Ancient Egypt provides an example of an early culture civilization.A '''civilization''' () is any complex society characterized by the development of the state, social stratification, urbanization, and symbolic systems of communication beyond natural spoken language (namely, a writing system).Civilizations are often characterized by additional features as well, including agriculture, architecture, infrastructure, technological advancement, a currency, taxation, regulation, and specialization of labour.Historically, a civilization has often been understood as a larger and \"more advanced\" culture, in implied contrast to smaller, supposedly less advanced cultures.", "In this broad sense, a civilization contrasts with non-centralized tribal societies, including the cultures of nomadic pastoralists, Neolithic societies, or hunter-gatherers; however, sometimes it also contrasts with the cultures found within civilizations themselves.", "Civilizations are organized densely-populated settlements divided into hierarchical social classes with a ruling elite and subordinate urban and rural populations, which engage in intensive agriculture, mining, small-scale manufacture and trade.", "Civilization concentrates power, extending human control over the rest of nature, including over other human beings.The word ''civilization'' relates to the Latin or 'city'.", "As the National Geographic Society has explained it: \"This is why the most basic definition of the word ''civilization'' is 'a society made up of cities.", "'\"The earliest emergence of civilizations is generally connected with the final stages of the Neolithic Revolution in West Asia, culminating in the relatively rapid process of urban revolution and state formation, a political development associated with the appearance of a governing elite." ], [ "History of the concept", "''The End of Dinner'' by Jules-Alexandre Grün (1913).", "The emergence of table manners and other forms of etiquette and self-restraint are presented as a characteristic of ''civilized'' society by Norbert Elias in his book ''The Civilizing Process'' (1939).", "The English word ''civilization'' comes from the 16th-century French ('civilized'), from ('civil'), related to ('citizen') and ('city').", "The fundamental treatise is Norbert Elias's ''The Civilizing Process'' (1939), which traces social mores from medieval courtly society to the early modern period.", "In ''The Philosophy of Civilization'' (1923), Albert Schweitzer outlines two opinions: one purely material and the other material and ethical.", "He said that the world crisis was from humanity losing the ethical idea of civilization, \"the sum total of all progress made by man in every sphere of action and from every point of view in so far as the progress helps towards the spiritual perfecting of individuals as the progress of all progress\".Related words like \"civility\" developed in the mid-16th century.", "The abstract noun \"civilization\", meaning \"civilized condition\", came in the 1760s, again from French.", "The first known use in French is in 1757, by Victor de Riqueti, marquis de Mirabeau, and the first use in English is attributed to Adam Ferguson, who in his 1767 ''Essay on the History of Civil Society'' wrote, \"Not only the individual advances from infancy to manhood but the species itself from rudeness to civilisation\".", "The word was therefore opposed to barbarism or rudeness, in the active pursuit of progress characteristic of the Age of Enlightenment.In the late 1700s and early 1800s, during the French Revolution, \"civilization\" was used in the singular, never in the plural, and meant the progress of humanity as a whole.", "This is still the case in French.", "The use of \"civilizations\" as a countable noun was in occasional use in the 19th century, but has become much more common in the later 20th century, sometimes just meaning culture (itself in origin an uncountable noun, made countable in the context of ethnography).", "Only in this generalized sense does it become possible to speak of a \"medieval civilization\", which in Elias's sense would have been an oxymoron.", "Using the terms \"civilization\" and \"culture\" as equivalents are controversial and generally rejected so that for example some types of culture are not normally described as civilizations.Already in the 18th century, civilization was not always seen as an improvement.", "One historically important distinction between culture and civilization is from the writings of Rousseau, particularly his work about education, ''Emile''.", "Here, civilization, being more rational and socially driven, is not fully in accord with human nature, and \"human wholeness is achievable only through the recovery of or approximation to an original discursive or prerational natural unity\" (see noble savage).", "From this, a new approach was developed, especially in Germany, first by Johann Gottfried Herder and later by philosophers such as Kierkegaard and Nietzsche.", "This sees cultures as natural organisms, not defined by \"conscious, rational, deliberative acts\", but a kind of pre-rational \"folk spirit\".", "Civilization, in contrast, though more rational and more successful in material progress, is unnatural and leads to \"vices of social life\" such as guile, hypocrisy, envy and avarice.", "In World War II, Leo Strauss, having fled Germany, argued in New York that this opinion of civilization was behind Nazism and German militarism and nihilism." ], [ "Characteristics", "The Acropolis of Athens: Greece is traditionally seen as the cradle of a distinct European or \"Western\" civilization.Social scientists such as V. Gordon Childe have named a number of traits that distinguish a civilization from other kinds of society.", "Civilizations have been distinguished by their means of subsistence, types of livelihood, settlement patterns, forms of government, social stratification, economic systems, literacy and other cultural traits.", "Andrew Nikiforuk argues that \"civilizations relied on shackled human muscle.", "It took the energy of slaves to plant crops, clothe emperors, and build cities\" and considers slavery to be a common feature of pre-modern civilizations.All civilizations have depended on agriculture for subsistence, with the possible exception of some early civilizations in Peru which may have depended upon maritime resources.The traditional \"surplus model\" postulates that cereal farming results in accumulated storage and a surplus of food, particularly when people use intensive agricultural techniques such as artificial fertilization, irrigation and crop rotation.", "It is possible but more difficult to accumulate horticultural production, and so civilizations based on horticultural gardening have been very rare.", "Grain surpluses have been especially important because grain can be stored for a long time.Research from the ''Journal of Political Economy'' contradicts the surplus model.", "It postulates that horticultural gardening was more productive than cereal farming.", "However, only cereal farming produced civilization because of the appropriability of yearly harvest.", "Rural populations that could only grow cereals could be taxed allowing for a taxing elite and urban development.", "This also had a negative effect on rural population, increasing relative agricultural output per farmer.", "Farming efficiency created food surplus and sustained the food surplus through decreasing rural population growth in favour of urban growth.", "Suitability of highly productive roots and tubers was in fact a curse of plenty, which prevented the emergence of states and impeded economic development.A surplus of food permits some people to do things besides producing food for a living: early civilizations included soldiers, artisans, priests and priestesses, and other people with specialized careers.", "A surplus of food results in a division of labour and a more diverse range of human activity, a defining trait of civilizations.", "However, in some places hunter-gatherers have had access to food surpluses, such as among some of the indigenous peoples of the Pacific Northwest and perhaps during the Mesolithic Natufian culture.", "It is possible that food surpluses and relatively large scale social organization and division of labour predates plant and animal domestication.Civilizations have distinctly different settlement patterns from other societies.", "The word ''civilization'' is sometimes defined as \"living in cities\".", "Non-farmers tend to gather in cities to work and to trade.Compared with other societies, civilizations have a more complex political structure, namely the state.", "State societies are more stratified than other societies; there is a greater difference among the social classes.", "The ruling class, normally concentrated in the cities, has control over much of the surplus and exercises its will through the actions of a government or bureaucracy.", "Morton Fried, a conflict theorist and Elman Service, an integration theorist, have classified human cultures based on political systems and social inequality.", "This system of classification contains four categories.", "* ''Hunter-gatherer bands'', which are generally egalitarian.", "* ''Horticultural–pastoralist societies'' in which there are generally two inherited social classes: chief and commoner.", "* ''Highly stratified structures'', or chiefdoms, with several inherited social classes: king, noble, freemen, serf and slave.", "* ''Civilizations'', with complex social hierarchies and organized, institutional forms of government.Economically, civilizations display more complex patterns of ownership and exchange than less organized societies.", "Living in one place allows people to accumulate more personal possessions than nomadic people.", "Some people also acquire landed property, or private ownership of the land.", "Because a percentage of people in civilizations do not grow their own food, they must trade their goods and services for food in a market system, or receive food through the levy of tribute, redistributive taxation, tariffs or tithes from the food producing segment of the population.", "Early human cultures functioned through a gift economy supplemented by limited barter systems.", "By the early Iron Age, contemporary civilizations developed money as a medium of exchange for increasingly complex transactions.", "In a village, the potter makes a pot for the brewer and the brewer compensates the potter by giving him a certain amount of beer.", "In a city, the potter may need a new roof, the roofer may need new shoes, the cobbler may need new horseshoes, the blacksmith may need a new coat and the tanner may need a new pot.", "These people may not be personally acquainted with one another and their needs may not occur all at the same time.", "A monetary system is a way of organizing these obligations to ensure that they are fulfilled.", "From the days of the earliest monetarized civilizations, monopolistic controls of monetary systems have benefited the social and political elites.The transition from simpler to more complex economies does not necessarily mean an improvement in the living standards of the populace.", "For example, although the Middle Ages is often portrayed as an era of decline from the Roman Empire, studies have shown that the average stature of males in the Middle Ages (c. 500 to 1500 CE) was greater than it was for males during the preceding Roman Empire and the succeeding Early Modern Period (c. 1500 to 1800 CE).", "Also, the Plains Indians of North America in the 19th century were taller than their \"civilized\" American and European counterparts.", "The average stature of a population is a good measurement of the adequacy of its access to necessities, especially food, and its freedom from disease.Writing, developed first by people in Sumer, is considered a hallmark of civilization and \"appears to accompany the rise of complex administrative bureaucracies or the conquest state\".", "Traders and bureaucrats relied on writing to keep accurate records.", "Like money, the writing was necessitated by the size of the population of a city and the complexity of its commerce among people who are not all personally acquainted with each other.", "However, writing is not always necessary for civilization, as shown by the Inca civilization of the Andes, which did not use writing at all but except for a complex recording system consisting of knotted strings of different lengths and colors: the \"Quipus\", and still functioned as a civilized society.Aristotle, the Ancient Greek philosopher and scientistAided by their division of labour and central government planning, civilizations have developed many other diverse cultural traits.", "These include organized religion, development in the arts, and countless new advances in science and technology.Assessments of what level of civilization a polity has reached are based on comparisons of the relative importance of agricultural as opposed to trading or manufacturing capacities, the territorial extensions of its power, the complexity of its division of labour, and the carrying capacity of its urban centres.", "Secondary elements include a developed transportation system, writing, standardized measurement, currency, contractual and tort-based legal systems, art, architecture, mathematics, scientific understanding, metallurgy, political structures, and organized religion.===As a contrast with other societies===The idea of civilization implies a progression or development from a previous \"uncivilized\" state.", "Traditionally, cultures that defined themselves as \"civilized\" often did so in contrast to other societies or human groupings viewed as less civilized, calling the latter barbarians, savages, and primitives.", "Indeed, the modern Western idea of civilization developed as a contrast to the indigenous cultures European settlers encountered the European colonization of the Americas and Australia.", "The term \"primitive,\" though once used in anthropology, has now been largely condemned by anthropologists because of its derogatory connotations and because it implies that the cultures it refers to are relics of a past time that do not change or progress.Because of this, societies regarding themselves as \"civilized\" have sometimes sought to dominate and assimilate \"uncivilized\" cultures into a \"civilized\" way of living.", "In the 19th century, the idea of European culture as \"civilized\" and superior to \"uncivilized\" non-European cultures was fully developed, and civilization became a core part of European identity.", "The idea of civilization can also be used as a justification for dominating another culture and dispossessing a people of their land.", "For example, in Australia, British settlers justified the displacement of Indigenous Australians by observing that the land appeared uncultivated and wild, which to them reflected that the inhabitants were not civilized enough to \"improve\" it.", "The behaviors and modes of subsistence that characterize civilization have been spread by colonization, invasion, religious conversion, the extension of bureaucratic control and trade, and by the introduction of new technologies to cultures that did not previously have them.", "Though aspects of culture associated with civilization can be freely adopted through contact between cultures, since early modern times Eurocentric ideals of \"civilization\" have been widely imposed upon cultures through coercion and dominance.", "These ideals complemented a philosophy that assumed there were innate differences between \"civilized\" and \"uncivilized\" peoples." ], [ "Cultural identity", "\"Civilization\" can also refer to the culture of a complex society, not just the society itself.", "Every society, civilization or not, has a specific set of ideas and customs, and a certain set of manufactures and arts that make it unique.", "Civilizations tend to develop intricate cultures, including a state-based decision-making apparatus, a literature, professional art, architecture, organized religion and complex customs of education, coercion and control associated with maintaining the elite.The intricate culture associated with civilization has a tendency to spread to and influence other cultures, sometimes assimilating them into the civilization, a classic example being Chinese civilization and its influence on nearby civilizations such as Korea, Japan and Vietnam Many civilizations are actually large cultural spheres containing many nations and regions.", "The civilization in which someone lives is that person's broadest cultural identity.A Blue Shield International mission in Libya during the war in 2011 to protect the cultural assets there.It is precisely the protection of this cultural identity that is becoming increasingly important nationally and internationally.", "According to international law, the United Nations and UNESCO try to set up and enforce relevant rules.", "The aim is to preserve the cultural heritage of humanity and also the cultural identity, especially in the case of war and armed conflict.", "According to Karl von Habsburg, President of Blue Shield International, the destruction of cultural assets is also part of psychological warfare.", "The target of the attack is often the opponent's cultural identity, which is why symbolic cultural assets become a main target.", "It is also intended to destroy the particularly sensitive cultural memory (museums, archives, monuments, etc.", "), the grown cultural diversity, and the economic basis (such as tourism) of a state, region or community.Many historians have focused on these broad cultural spheres and have treated civilizations as discrete units.", "Early twentieth-century philosopher Oswald Spengler, uses the German word ''Kultur'', \"culture\", for what many call a \"civilization\".", "Spengler believed a civilization's coherence is based on a single primary cultural symbol.", "Cultures experience cycles of birth, life, decline, and death, often supplanted by a potent new culture, formed around a compelling new cultural symbol.", "Spengler states civilization is the beginning of the decline of a culture as \"the most external and artificial states of which a species of developed humanity is capable\".This \"unified culture\" concept of civilization also influenced the theories of historian Arnold J. Toynbee in the mid-twentieth century.", "Toynbee explored civilization processes in his multi-volume ''A Study of History'', which traced the rise and, in most cases, the decline of 21 civilizations and five \"arrested civilizations\".", "Civilizations generally declined and fell, according to Toynbee, because of the failure of a \"creative minority\", through moral or religious decline, to meet some important challenge, rather than mere economic or environmental causes.Samuel P. Huntington defines civilization as \"the highest cultural grouping of people and the broadest level of cultural identity people have short of that which distinguishes humans from other species\"." ], [ "Complex systems", "Depiction of united Medes and Persians at the Apadana, Persepolis.Another group of theorists, making use of systems theory, looks at a civilization as a complex system, i.e., a framework by which a group of objects can be analysed that work in concert to produce some result.", "Civilizations can be seen as networks of cities that emerge from pre-urban cultures and are defined by the economic, political, military, diplomatic, social and cultural interactions among them.", "Any organization is a complex social system and a civilization is a large organization.", "Systems theory helps guard against superficial and misleading analogies in the study and description of civilizations.Systems theorists look at many types of relations between cities, including economic relations, cultural exchanges and political/diplomatic/military relations.", "These spheres often occur on different scales.", "For example, trade networks were, until the nineteenth century, much larger than either cultural spheres or political spheres.", "Extensive trade routes, including the Silk Road through Central Asia and Indian Ocean sea routes linking the Roman Empire, Persian Empire, India and China, were well established 2000 years ago when these civilizations scarcely shared any political, diplomatic, military, or cultural relations.", "The first evidence of such long-distance trade is in the ancient world.", "During the Uruk period, Guillermo Algaze has argued that trade relations connected Egypt, Mesopotamia, Iran and Afghanistan.", "Resin found later in the Royal Cemetery at Ur is suggested was traded northwards from Mozambique.Many theorists argue that the entire world has already become integrated into a single \"world system\", a process known as globalization.", "Different civilizations and societies all over the globe are economically, politically, and even culturally interdependent in many ways.", "There is debate over when this integration began, and what sort of integration – cultural, technological, economic, political, or military-diplomatic – is the key indicator in determining the extent of a civilization.", "David Wilkinson has proposed that economic and military-diplomatic integration of the Mesopotamian and Egyptian civilizations resulted in the creation of what he calls the \"Central Civilization\" around 1500 BCE.", "Central Civilization later expanded to include the entire Middle East and Europe, and then expanded to a global scale with European colonization, integrating the Americas, Australia, China and Japan by the nineteenth century.", "According to Wilkinson, civilizations can be culturally heterogeneous, like the Central Civilization, or homogeneous, like the Japanese civilization.", "What Huntington calls the \"clash of civilizations\" might be characterized by Wilkinson as a clash of cultural spheres within a single global civilization.", "Others point to the Crusading movement as the first step in globalization.", "The more conventional viewpoint is that networks of societies have expanded and shrunk since ancient times, and that the current globalized economy and culture is a product of recent European colonialism." ], [ "History", "The notion of human history as a succession of \"civilizations\" is an entirely modern one.", "In the European Age of Discovery, emerging Modernity was put into stark contrast with the Neolithic and Mesolithic stage of the cultures of many of the peoples they encountered.", "Nonetheless, developments in the Neolithic stage, such as agriculture and sedentary settlement, were critical to the development of modern conceptions of civilization.===Urban Revolution===The Natufian culture in the Levantine corridor provides the earliest case of a Neolithic Revolution, with the planting of cereal crops attested from 11,000 BCE.", "The earliest neolithic technology and lifestyle were established first in Western Asia (for example at Göbekli Tepe, from about 9,130 BCE), later in the Yellow River and Yangtze basins in China (for example the Peiligang and Pengtoushan cultures), and from these cores spread across Eurasia.", "Mesopotamia is the site of the earliest civilizations developing from 7,400 years ago.", "This area has been evaluated by Beverley Milton-Edwards as having \"inspired some of the most important developments in human history including the invention of the wheel, the building of the earliest cities and the development of written cursive script\".Similar pre-civilized \"neolithic revolutions\" also began independently from 7,000 BCE in northwestern South America (the Caral-Supe civilization) and in Mesoamerica.", "The Black Sea area served as a cradle of European civilization.", "The site of Solnitsata – a prehistoric fortified (walled) stone settlement (prehistoric city) (5500–4200 BCE) – is believed by some archeologists to be the oldest known town in present-day Europe.The 8.2 Kiloyear Arid Event and the 5.9 Kiloyear Interpluvial saw the drying out of semiarid regions and a major spread of deserts.", "This climate change shifted the cost-benefit ratio of endemic violence between communities, which saw the abandonment of unwalled village communities and the appearance of walled cities, seen by some as a characteristic of early civilizations.The ruins of Mesoamerican city TeotihuacanThis \"urban revolution\" –a term introduced by Childe in the 1930s– from the 4th millennium BCE, marked the beginning of the accumulation of transferable economic surpluses, which helped economies and cities develop.", "Urban revolutions were associated with the state monopoly of violence, the appearance of a warrior, or soldier, class and endemic warfare (a state of continual or frequent warfare), the rapid development of hierarchies, and the use of human sacrifice.The civilized urban revolution in turn was dependent upon the development of sedentism, the domestication of grains, plants and animals, the permanence of settlements and development of lifestyles that facilitated economies of scale and accumulation of surplus production by particular social sectors.", "The transition from ''complex cultures'' to ''civilizations'', while still disputed, seems to be associated with the development of state structures, in which power was further monopolized by an élite ruling class who practiced human sacrifice.Towards the end of the Neolithic period, various elitist Chalcolithic civilizations began to rise in various \"cradles\" from around 3600 BCE beginning with Mesopotamia, expanding into large-scale kingdoms and empires in the course of the Bronze Age (Akkadian Empire, Indus Valley Civilization, Old Kingdom of Egypt, Neo-Sumerian Empire, Middle Assyrian Empire, Babylonian Empire, Hittite Empire, and to some degree the territorial expansions of the Elamites, Hurrians, Amorites and Ebla).Outside the Old World, a later development took place independently in the Pre-Columbian Americas.", "Urbanization in the Norte Chico civilization in coastal Peru emerged about 3200 BCE; the oldest known Mayan city, located in Guatemala, dates to about 750 BCE.", "and Teotihuacan in Mexico was one of the largest cities in the world in 350 CE, with a population of about 125,000.=== Axial Age ===The Bronze Age collapse was followed by the Iron Age around 1200 BCE, during which a number of new civilizations emerged, culminating in a period from the 8th to the 3rd century BCE which Karl Jaspers termed the Axial Age, presented as a critical transitional phase leading to classical civilization.=== Modernity ===A major technological and cultural transition to modernity began approximately 1500 CE in Western Europe, and from this beginning new approaches to science and law spread rapidly around the world, incorporating earlier cultures into the technological and industrial society of the present." ], [ "Fall of civilizations", "Civilizations are traditionally understood as ending in one of two ways; either through incorporation into another expanding civilization (e.g.", "as Ancient Egypt was incorporated into Hellenistic Greek, and subsequently Roman civilizations), or by collapsing and reverting to a simpler form of living, as happens in so-called Dark Ages.There have been many explanations put forward for the collapse of civilization.", "Some focus on historical examples, and others on general theory.", "* Ibn Khaldun's ''Muqaddimah'' influenced theories of the analysis, growth, and decline of the Islamic civilization.", "He suggested repeated invasions from nomadic peoples limited development and led to social collapse.Barbarian invasions played an important role in the fall of the Roman Empire.", "* Edward Gibbon's work ''The Decline and Fall of the Roman Empire'' is a well-known and detailed analysis of the fall of Roman civilization.", "Gibbon suggested the final act of the collapse of Rome was the fall of Constantinople to the Ottoman Turks in 1453 CE.", "For Gibbon, \"The decline of Rome was the natural and inevitable effect of immoderate greatness.", "Prosperity ripened the principle of decay; the cause of the destruction multiplied with the extent of conquest; and, as soon as time or accident had removed the artificial supports, the stupendous fabric yielded to the pressure of its own weight.", "The story of the ruin is simple and obvious; and instead of inquiring why the Roman Empire was destroyed, we should rather be surprised that it has subsisted for so long\".", "* Theodor Mommsen in his ''History of Rome'' suggested Rome collapsed with the collapse of the Western Roman Empire in 476 CE and he also tended towards a biological analogy of \"genesis\", \"growth\", \"senescence\", \"collapse\" and \"decay\".", "* Oswald Spengler, in his ''Decline of the West'' rejected Petrarch's chronological division, and suggested that there had been only eight \"mature civilizations\".", "Growing cultures, he argued, tend to develop into imperialistic civilizations, which expand and ultimately collapse, with democratic forms of government ushering in plutocracy and ultimately imperialism.", "* Arnold J. Toynbee in his ''A Study of History'' suggested that there had been a much larger number of civilizations, including a small number of arrested civilizations, and that all civilizations tended to go through the cycle identified by Mommsen.", "The cause of the fall of a civilization occurred when a cultural elite became a parasitic elite, leading to the rise of internal and external proletariats.", "* Joseph Tainter in ''The Collapse of Complex Societies'' suggested that there were diminishing returns to complexity, due to which, as states achieved a maximum permissible complexity, they would decline when further increases actually produced a negative return.", "Tainter suggested that Rome achieved this figure in the 2nd century CE.", "* Jared Diamond in his 2005 book ''Collapse: How Societies Choose to Fail or Succeed'' suggests five major reasons for the collapse of 41 studied cultures: environmental damage, such as deforestation and soil erosion; climate change; dependence upon long-distance trade for needed resources; increasing levels of internal and external violence, such as war or invasion; and societal responses to internal and environmental problems.", "* Peter Turchin in his ''Historical Dynamics'' and Andrey Korotayev ''et al.''", "in their ''Introduction to Social Macrodynamics, Secular Cycles, and Millennial Trends'' suggest a number of mathematical models describing collapse of agrarian civilizations.", "For example, the basic logic of Turchin's \"fiscal-demographic\" model can be outlined as follows: during the initial phase of a sociodemographic cycle we observe relatively high levels of per capita production and consumption, which leads not only to relatively high population growth rates, but also to relatively high rates of surplus production.", "As a result, during this phase the population can afford to pay taxes without great problems, the taxes are quite easily collectible, and the population growth is accompanied by the growth of state revenues.", "During the intermediate phase, the increasing population growth leads to the decrease of per capita production and consumption levels, it becomes more and more difficult to collect taxes, and state revenues stop growing, whereas the state expenditures grow due to the growth of the population controlled by the state.", "As a result, during this phase the state starts experiencing considerable fiscal problems.", "During the final pre-collapse phases the overpopulation leads to further decrease of per capita production, the surplus production further decreases, state revenues shrink, but the state needs more and more resources to control the growing (though with lower and lower rates) population.", "Eventually this leads to famines, epidemics, state breakdown, and demographic and civilization collapse.", "* Peter Heather argues in his book ''The Fall of the Roman Empire: a New History of Rome and the Barbarians'' that this civilization did not end for moral or economic reasons, but because centuries of contact with barbarians across the frontier generated its own nemesis by making them a more sophisticated and dangerous adversary.", "The fact that Rome needed to generate ever greater revenues to equip and re-equip armies that were for the first time repeatedly defeated in the field, led to the dismemberment of the Empire.", "Although this argument is specific to Rome, it can also be applied to the Asiatic Empire of the Egyptians, to the Han and Tang dynasties of China, to the Muslim Abbasid Caliphate and others.", "* Bryan Ward-Perkins, in his book ''The Fall of Rome and the End of Civilization'', argues from mostly archaeological evidence that the collapse of Roman civilization in western Europe had deleterious impacts on the living standards of the population, unlike some historians who downplay this.", "The collapse of complex society meant that even basic plumbing for the elite disappeared from the continent for 1,000 years.", "Similar impacts have been postulated for the Dark Age after the Late Bronze Age collapse in the Eastern Mediterranean, the collapse of the Maya, on Easter Island and elsewhere.", "* Arthur Demarest argues in ''Ancient Maya: The Rise and Fall of a Rainforest Civilization'', using a holistic perspective to the most recent evidence from archeology, paleoecology, and epigraphy, that no one explanation is sufficient but that a series of erratic, complex events, including loss of soil fertility, drought and rising levels of internal and external violence led to the disintegration of the courts of Mayan kingdoms, which began a spiral of decline and decay.", "He argues that the collapse of the Maya has lessons for civilization today.", "* Jeffrey A. McNeely has recently suggested that \"a review of historical evidence shows that past civilizations have tended to over-exploit their forests, and that such abuse of important resources has been a significant factor in the decline of the over-exploiting society\".", "* Thomas Homer-Dixon considers the fall in the energy return on investments.", "The energy expended to energy yield ratio is central to limiting the survival of civilizations.", "The degree of social complexity is associated strongly, he suggests, with the amount of disposable energy environmental, economic and technological systems allow.", "When this amount decreases civilizations either have to access new energy sources or collapse.", "* Feliks Koneczny in his work \"On the Plurality of Civilizations\" calls his study the science on civilizations.", "He asserts that civilizations fall not because they must or there exist some cyclical or a \"biological\" life span and that there stil exist two ancient civilizations – Brahmin-Hindu and Chinese – which are not ready to fall any time soon.", "Koneczny claimed that civilizations cannot be mixed into hybrids, an inferior civilization when given equal rights within a highly developed civilization will overcome it.", "One of Koneczny's claims in his study on civilizations is that \"a person cannot be civilized in two or more ways\" without falling into what he calls an \"abcivilized state\" (as in abnormal).", "He also stated that when two or more civilizations exist next to one another and as long as they are vital, they will be in an existential combat imposing its own \"method of organizing social life\" upon the other.", "Absorbing alien \"method of organizing social life\" that is civilization and giving it equal rights yields a process of decay and decomposition." ], [ "Future", "A world map of major civilizations according to the political hypothesis ''Clash of Civilizations'' by Samuel P. Huntington.According to political scientist Samuel P. Huntington, the 21st century will be characterized by a clash of civilizations, which he believes will replace the conflicts between nation-states and ideologies that were prominent in the 19th and 20th centuries.", "However, this viewpoint been strongly challenged by others such as Edward Said, Muhammed Asadi and Amartya Sen. Ronald Inglehart and Pippa Norris have argued that the \"true clash of civilizations\" between the Muslim world and the West is caused by the Muslim rejection of the West's more liberal sexual values, rather than a difference in political ideology, although they note that this lack of tolerance is likely to lead to an eventual rejection of (true) democracy.", "In ''Identity and Violence'' Sen questions if people should be divided along the lines of a supposed \"civilization\", defined by religion and culture only.", "He argues that this ignores the many others identities that make up people and leads to a focus on differences.Cultural Historian Morris Berman argues in ''Dark Ages America: the End of Empire'' that in the corporate consumerist United States, the very factors that once propelled it to greatness―extreme individualism, territorial and economic expansion, and the pursuit of material wealth―have pushed the United States across a critical threshold where collapse is inevitable.", "Politically associated with over-reach, and as a result of the environmental exhaustion and polarization of wealth between rich and poor, he concludes the current system is fast arriving at a situation where continuation of the existing system saddled with huge deficits and a hollowed-out economy is physically, socially, economically and politically impossible.", "Although developed in much more depth, Berman's thesis is similar in some ways to that of Urban Planner, Jane Jacobs who argues that the five pillars of United States culture are in serious decay: community and family; higher education; the effective practice of science; taxation and government; and the self-regulation of the learned professions.", "The corrosion of these pillars, Jacobs argues, is linked to societal ills such as environmental crisis, racism and the growing gulf between rich and poor.Cultural critic and author Derrick Jensen argues that modern civilization is directed towards the domination of the environment and humanity itself in an intrinsically harmful, unsustainable, and self-destructive fashion.", "Defending his definition both linguistically and historically, he defines civilization as \"a culture... that both leads to and emerges from the growth of cities\", with \"cities\" defined as \"people living more or less permanently in one place in densities high enough to require the routine importation of food and other necessities of life\".", "This need for civilizations to import ever more resources, he argues, stems from their over-exploitation and diminution of their own local resources.", "Therefore, civilizations inherently adopt imperialist and expansionist policies and, to maintain these, highly militarized, hierarchically structured, and coercion-based cultures and lifestyles.The Kardashev scale classifies civilizations based on their level of technological advancement, specifically measured by the amount of energy a civilization is able to harness.", "The scale is only hypothetical, but it puts energy consumption in a cosmic perspective.", "The Kardashev scale makes provisions for civilizations far more technologically advanced than any currently known to exist." ], [ "Non-human civilizations", "The current scientific consensus is that human beings are the only animal species with the cognitive ability to create civilizations that has emerged on Earth.", "A recent thought experiment, the silurian hypothesis, however, considers whether it would \"be possible to detect an industrial civilization in the geological record\" given the paucity of geological information about eras before the quaternary.Astronomers speculate about the existence of communicating intelligent civilizations within and beyond the Milky Way galaxy, usually using variants of the Drake equation.", "They conduct searches for such intelligences – such as for technological traces, called \"technosignatures\".", "The proposed proto-scientific field \"xenoarchaeology\" is concerned with the study of artifact remains of non-human civilizations to reconstruct and interpret past lives of alien societies if such get discovered and confirmed scientifically." ], [ "See also" ], [ "Notes" ], [ "References" ], [ "Bibliography", "* * * * * * * * * * * * * *# ''From the Earliest Times to the Battle of Lepanto''.", "(1987 reprint).", "*# ''From the Defeat of the Spanish Armada to the Battle of Waterloo''.", "(1987 reprint).", "*# ''From the American Civil War to the End of World War II''.", "(1987 reprint).", "* * * * * * * * * Korotayev, Andrey, ''World Religions and Social Evolution of the Old World Oikumene Civilizations: A Cross-Cultural Perspective''.", "Lewiston, New York: Edwin Mellen Press, 2004.", "* Kradin, Nikolay.", "Archaeological Criteria of Civilization.", "''Social Evolution & History'', Vol.", "5, No 1 (2006): 89–108..* * * * * * * * * * * *" ], [ "Further reading", "* Gribbin, John, \"Alone in the Milky Way: Why we are probably the only intelligent life in the galaxy\", ''Scientific American'', vol.", "319, no.", "3 (September 2018), pp. 94–99.", "\"Is life likely to exist elsewhere in the Milky Way galaxy?", "Almost certainly yes, given the speed with which it appeared on Earth.", "Is another technological civilization likely to exist today?", "Almost certainly no, given the chain of circumstances that led to our existence.", "These considerations suggest that we are unique not just on our planet but in the whole Milky Way.", "And if our planet is so special, it becomes all the more important to preserve this unique world for ourselves, our descendants and the many creatures that call Earth home.\"", "(p. 99.)" ], [ "External links", "* * BBC on civilization* Top 10 oldest civilizations" ] ]
wikipedia
[ [ "Civilization (video game)" ], [ "Introduction", "'''''Sid Meier's Civilization''''' is a 1991 turn-based strategy 4X video game developed and published by MicroProse.", "The game was originally developed for MS-DOS running on a PC, and it has undergone numerous revisions for various platforms.", "The player is tasked with leading an entire human civilization over the course of several millennia by controlling various areas such as urban development, exploration, government, trade, research, and military.", "The player can control individual units and advance the exploration, conquest and settlement of the game's world.", "The player can also make such decisions as setting forms of government, tax rates and research priorities.", "The player's civilization is in competition with other computer-controlled civilizations, with which the player can enter diplomatic relationships that can either end in alliances or lead to war.", "''Civilization'' was designed by Sid Meier and Bruce Shelley following the successes of ''Silent Service'', ''Sid Meier's Pirates!''", "and ''Railroad Tycoon''.", "''Civilization'' has sold 1.5 million copies since its release and is considered one of the most influential computer games in history due to its establishment of the 4X genre.", "In addition to its commercial and critical success, the game has been deemed pedagogically valuable due to its presentation of historical relationships, and one of the greatest video games ever made by several publications.", "A multiplayer remake, '''''Sid Meier's CivNet''''', was released for the PC in 1995.", "''Civilization'' was followed by several sequels starting with ''Civilization II'', with similar or modified scenarios." ], [ "Gameplay", "A world map screenshot from the Amiga version of ''Civilization''''Civilization'' is a turn-based single-player strategy game.", "The player takes on the role of the ruler of a civilization, starting with one (or occasionally two) settler units, and attempts to build an empire in competition with two to seven other civilizations.", "The game requires a fair amount of micromanagement (although less than other simulation games).", "Along with the larger tasks of exploration, warfare and diplomacy, the player has to make decisions about where to build new cities, which improvements or units to build in each city, which advances in knowledge should be sought (and at what rate), and how to transform the land surrounding the cities for maximum benefit.", "From time to time the player's towns may be harassed by barbarians, units with no specific nationality and no named leader.", "These threats only come from huts, unclaimed land or sea, so that over time and turns of exploration, there are fewer and fewer places from which barbarians will emanate.Before the game begins, the player chooses which historical or current civilization to play.", "In contrast to later games in the ''Civilization'' series, this is largely a cosmetic choice, affecting titles, city names, musical heralds, and color.", "The choice does affect their starting position on the \"Play on Earth\" map, and thus different resources in one's initial cities, but has no effect on starting position when starting a random world game or a customized world game.", "The player's choice of civilization also prevents the computer from being able to play as that civilization or the other civilization of the same color, and since computer-controlled opponents display certain traits of their civilizations this affects gameplay as well.", "The Aztecs are both fiercely expansionist and generally extremely wealthy, for example.", "Other civilizations include the Americans, the Mongols, and Romans.", "Each civilization is led by a famous historical figure, such as Mahatma Gandhi for India.The scope of ''Civilization'' is larger than most other games.", "The game begins in 4000 BC, before the Bronze Age, and can last through to AD 2100 (on the easiest setting) with Space Age and \"future technologies\".", "At the start of the game there are no cities anywhere in the world: the player controls one or two settler units, which can be used to found new cities in appropriate sites (and those cities may build other settler units, which can go out and found new cities, thus expanding the empire).", "Settlers can also alter terrain, build improvements such as mines and irrigation, build roads to connect cities, and later in the game they can construct railroads which offer unlimited movement.As time advances, new technologies are developed; these technologies are the primary way in which the game changes and grows.", "At the start, players choose from advances such as pottery, the wheel, and the alphabet to, near the end of the game, nuclear fission and spaceflight.", "Players can gain a large advantage if their civilization is the first to learn a particular technology (the secrets of flight, for example) and put it to use in a military or other context.", "Most advances give access to new units, city improvements or derivative technologies: for example, the chariot unit becomes available after the wheel is developed, and the granary building becomes available to build after pottery is developed.", "The whole system of advancements from beginning to end is called the technology tree, or simply the Tech tree; this concept has been adopted in many other strategy games.", "Since only one tech may be \"researched\" at any given time, the order in which technologies are chosen makes a considerable difference in the outcome of the game and generally reflects the player's preferred style of gameplay.Players can also build ''Wonders of the World'' in each of the epochs of the game, subject only to obtaining the prerequisite knowledge.", "These wonders are important achievements of society, science, culture and defense, ranging from the Pyramids and the Great Wall in the Ancient age, to Copernicus' Observatory and Magellan's Expedition in the middle period, up to the Apollo program, the United Nations, and the Manhattan Project in the modern era.", "Each wonder can only be built once in the world, and requires a lot of resources to build, far more than most other city buildings or units.", "Wonders provide unique benefits to the controlling civilization.", "For example, Magellan's Expedition increases the movement rate of naval units.", "Wonders typically affect either the city in which they are built (for example, the Colossus), every city on the continent (for example, J.S.", "Bach's Cathedral), or the civilization as a whole (for example, Darwin's Voyage).", "Some wonders are made obsolete by new technologies.The game can be won by conquering all other civilizations or by winning the space race by reaching the star system of Alpha Centauri." ], [ "Development", "===Prior ''Civilization''-named games===British designer Francis Tresham released his ''Civilization'' board game in 1980 under his company Hartland Trefoil.", "Avalon Hill had obtained the rights to publish it in the United States in 1981.There were at least two attempts to make a computerized version of Tresham's game prior to 1990.Danielle Bunten Berry planned to start work on the game after completing ''M.U.L.E.''", "in 1983, and again in 1985, after completing ''The Seven Cities of Gold'' at Electronic Arts.", "In 1983 Bunten and producer Joe Ybarra opted to first do ''Seven Cities of Gold''.", "The success of ''Seven Cities'' in 1985 in turn led to a sequel, ''Heart of Africa''.", "Bunten never returned to the idea of ''Civilization''.", "Don Daglow, designer of ''Utopia'', the first simulation game, began work programming a version of ''Civilization'' in 1987.He dropped the project, however, when he was offered an executive position at Brøderbund, and never returned to the game.===Development at MicroProse===Sid Meier (left) and Bruce Shelley at the 2017 Game Developers ConferenceSid Meier and Bill Stealey co-founded MicroProse in 1982 to develop flight simulators and other military strategy video games based on Stealey's past experiences as a United States Air Force pilot.", "Around 1989, Meier wanted to expand his repertoire beyond these types of games, as just having finished ''F-19 Stealth Fighter'' (1988, 1990), he said \"Everything I thought was cool about a flight simulator had gone into that game.\"", "He took to heart the success of the new god game genre, in particular ''SimCity'' (1989) and ''Populous'' (1989).", "Specifically with ''SimCity'', Meier recognized that video games could still be entertaining based on building something up.", "By then, Meier was not an official employee of MicroProse but worked under contract where the company paid him upfront for game development, a large payment on delivery of the game, and additional royalties on each game of his sold.MicroProse had hired a number of Avalon Hill game designers, including Bruce Shelley.", "Among other works, Shelley had been responsible for adapting the railroad-based ''1829'' board game developed by Tresham into ''1830: The Game of Railroads and Robber Barons''.", "Shelley had joined MicroProse finding that the board game market was weakening in contrast to the video game market, and initially worked on ''F-19 Stealth Fighter''.", "Meier recognized Shelley's abilities and background in game design and took him on as personal assistant designer to brainstorm new game ideas.", "The two initially worked on ideas for ''Covert Action'', but had put these aside when they came up with the concepts for ''Railroad Tycoon'' (1990), based loosely on the ''1829''/''1830'' board games.", "''Railroad Tycoon'' was generally well received at its release, but the title did not fit within the nature of flight simulators and military strategy from MicroProse's previous catalog.", "Meier and Shelley had started a sequel to ''Railroad Tycoon'' shortly after its release, but Stealey canceled the project.One positive aspect both had taken from ''Railroad Tycoon'' was the idea of multiple smaller systems working together at the same time and the player having to manage them.", "Both Meier and Shelley recognized that the complex interactions between these systems led players to \"make a lot of interesting decisions\", and that ruling a whole civilization would readily work well with these underlying systems.", "Some time later, both discussed their love of the original ''Empire'' computer games, and Meier challenged Shelley to give him ten things he would change about ''Empire''; Shelley provided him with twelve.", "Around May 1990, Meier presented Shelley with a 5-1/4\" floppy disk which contained the first prototype of ''Civilization'' based on their past discussions and Shelley's list.Meier described his development process as sculpting with clay.", "His prototype took elements from ''Empire'', ''Railroad Tycoon'', ''SimCity'' and the ''Civilization'' board game.", "This initial version of this game was a real-time simulation, with the player defining zones for their population to grow similar to zoning in ''SimCity''.", "Meier and Shelley went back and forth with this, with Shelley providing suggestions based on his playthrough and acting as the game's producer, and Meier coding and reworking the game to address these points, and otherwise without involvement of other MicroProse staff.", "During this period, Stealey and the other managers became concerned that this game did not fit MicroProse's general catalog as strategy computer games had not yet proven successful.", "A few months into the development, Stealey requested them to put the project on hold and complete ''Covert Action'', after which they could go back to their new game.", "Meier and Shelley completed ''Covert Action'' which was published in 1990.Meier introduced a technology tree in ''Civilization'', similar to this one from the open-source variation, ''Freeciv'', to create non-linear ways to play the game.Once ''Covert Action'' was released, Meier and Shelley returned to the prototype.", "The time away from the project allowed them to recognize that the real-time aspect was not working well, and reworked the game to become turn-based and dropped the zoning aspect, a change that Meier described as \"like tossing the clay in the trash and getting a new lump\".", "They incorporated elements of city management and military aspect from ''Empire'', including creating individual military units as well as settler units that replaced the functionality of the zoning approach.", "Meier felt adding military and combat to the game was necessary: \"The game really isn't about being civilized.", "The competition is what makes the game fun and the players play their best.", "At times, you have to make the player uncomfortable for the good of the player.\"", "Meier also opted to include a technology tree that would help to open the game to many more choices to the player as it continued, creating a non-linear experience.", "Meier felt players would be able to use the technology tree to adopt a style of play and from which they could use technologies to barter with the other opponents.", "While the game relies on established recorded history, Meier admitted he did not spend much time in research, usually only to assure the proper chronology or spellings; Shelley noted that they wanted to design for fun, not accuracy, and that \"Everything we needed was pretty much available in the children’s section of the library.", "\"''Computer Gaming World'' reported in 1994 that \"Sid Meier has stated on numerous occasions that he emphasizes the 'fun parts' of a simulation and throws out the rest\".", "Meier described the process as \"Add another bit of clay—no, that went too far.", "Scrape it off\".", "He eliminated the potential for any civilization to fall on its own, believing this would be punishing to the player.", "\"Though historically accurate\", Meier said, \"The moment the Krakatoa volcano blew up, or the bubonic plague came marching through, all anybody wanted to do was reload from asaved game\".", "Meier omitted multiplayer alliances because the computer used them too effectively, causing players to think that it was cheating.", "He said that by contrast, minefields and minesweepers caused the computer to do \"stupid things ...", "If you've got a feature that makes the AI look stupid, take it out.", "It's more important not to have stupid AI than to have good AI\".", "Meier also omitted jets and helicopters because he thought players would not find obtaining new technologies in the endgame useful, and online multiplayer support because of the small number of online players (\"if you had friends, you wouldn't need to play computer games\"); he also did not believe that online play worked well with turn-based play.", "The game was developed for the IBM PC platform, which at the time had support for both 16-color EGA to 256-color VGA; Meier opted to support both 16-color and 256-color graphics to allow the game to run on both EGA/Tandy and VGA/MCGA systems.", "\"I’ve never been able to decide if it was a mistake to keep Civ isolated as long as I did\", Meier wrote; while \"as many eyes as possible\" are beneficial during development, Meier and Shelley worked very quickly together, combining the roles of playtester, game designer, and programmer.", "Meier and Shelley neared the end of their development and started presenting the game to the rest of MicroProse for feedback towards publication.", "This process was slowed by the current vice president of development, who had taken over Meier's former position at the company.", "This vice president did not receive any financial bonuses for successful publication of Meier's games due to Meier's contract terms, forgoing any incentive to provide the needed resources to finish the game.", "The management had also expressed issue with the lack of a firm completion date, as according to Shelley, Meier would consider a game completed only when he felt he had completed it.", "Eventually the two got the required help for publication, with Shelley overseeing these processes and Meier making the necessary coding changes.", "\"One of my big rules has always been, 'double it, or cut it in half, Meier wrote.", "He cut the map's size in half less than a month before ''Civilization'' release after playtesting revealed that the previous size was too large and made for boring and repetitive gameplay.", "Other automated features, like city management, were modified to require more player involvement.", "They also eliminated a secondary branch of the technology tree with minor skills like beer brewing, and spent time reworking the existing technologies and units to make sure they felt appropriate and did not break the game.", "Most of the game was originally developed with art crafted by Meier, and MicroProse's art department helped to create most of the final assets, though some of Meier's original art was used.", "Shelley wrote out the \"Civilopedia\" entries for all the elements of the game and the game's large manual.The name ''Civilization'' came late in the development process.", "MicroProse recognized at this point the 1980 ''Civilization'' board game may conflict with their video game, as it shared a similar theme including the technology tree.", "Meier had noted the board game's influence but considered it not as great as ''Empire'' or ''SimCity'', while others have noted significant differences that made the video game far different from the board game such as the non-linearity introduced by Meier's technology tree.", "To avoid any potential legal issues, MicroProse negotiated a license to use the ''Civilization'' name from Avalon Hill.", "The addition of Meier's name to the title was from a current practice established by Stealey to attach games like ''Civilization'' that diverged from MicroProse's past catalog to Meier's name, so that players that played Meier's combat simulators and recognized Meier's name would give these new games a try.", "This approach worked, according to Meier, and he would continue this naming scheme for other titles in the future as a type of branding.By the time the game was completed and ready for release, Meier estimated that it had cost $170,000 in development.", "''Civilization'' was released in September 1991.Because of the animosity that MicroProse's management had towards Meier's games, there was very little promotion of the title, though interest in the game through word-of-mouth helped to boost sales.", "Following the release on the IBM PC, the game was ported to other platforms; Meier and Shelley provided this code to contractors hired by MicroProse to complete the ports.===''CivNet''===''Civilization'' was released with only single-player support, with the player working against multiple computer opponents.", "In 1991, Internet or online gaming was still in its infancy, so this option was not considered in ''Civilization'' release.", "Over the next few years, as home Internet accessibility took off, MicroProse looked to develop an online version of ''Civilization''.", "This led to the 1995 release of ''Sid Meier's CivNet''.", "''CivNet'' allowed for up to seven players to play the game, with computer opponents available to obtain up to six active civilizations.", "Games could be played either on a turn-based mode, or in a simultaneous mode where each player took their turn at the same time and only progressing to the next turn once all players have confirmed being finished that turn.", "The game, in addition to better support for Windows 3.1 and Windows 95, supported connectivity through LAN, primitive Internet play, modem, and direct serial link, and included a local hotseat mode.", "''CivNet'' also included a map editor and a \"king builder\" to allow a player to customize the names and looks of their civilization as seen by other players.According to Brian Reynolds, who led the development of ''Civilization II'', MicroProse \"sincerely believed that ''CivNet'' was going to be a much more important product\" than the next single-player ''Civilization'' game that he and Jeff Briggs had started working on.", "Reynolds said that because their project was seen as a side effort with little risk, they were able to innovate new ideas into ''Civilization II''.", "As a net result, ''CivNet'' was generally overshadowed by ''Civilization II'' which was released in the following year.===Post-release===''Civilization'' critical success created a \"golden period of MicroProse\" where there was more potential for similar strategy games to succeed, according to Meier.", "This put stress on the company's direction and culture.", "Stealey wanted to continue to pursue the military-themed titles, while Meier wanted to continue his success with simulation games.", "Shelley left MicroProse in 1992 and joined Ensemble Studios, where he used his experience with ''Civilization'' to design the ''Age of Empires'' games.", "Stealey had pushed MicroProse to develop console and arcade-based versions of their games, but this put the company into debt, and Stealey eventually sold the company to Spectrum HoloByte in 1993; Spectrum HoloByte kept MicroProse as a separate company on acquisition.Meier would continue and develop ''Civilization II'' along with Brian Reynolds, who served in a similar role to Shelley as design assistant, as well as help from Jeff Briggs and Douglas Kaufman.", "This game was released in early 1996, and is considered the first sequel of any Sid Meier game.", "Stealey eventually sold his shares in MicroProse and left the company, and Spectrum HoloByte opted to consolidate the two companies under the name MicroProse in 1996, eliminating numerous positions at MicroProse in the process.", "As a result, Meier, Briggs, and Reynolds all opted to leave the company and founded Firaxis, which by 2005 became a subsidiary of Take-Two.", "After a number of acquisitions and legal actions, the ''Civilization'' brand (both as a board game and video game) is now owned by Take-Two, and Firaxis, under Meier's oversight, continues to develop games in the ''Civilization'' series." ], [ "Reception", "''Civilization'' has been called one of the most important strategy games of all time, and has a loyal following of fans.", "This high level of interest has led to the creation of a number of free and open source versions and inspired similar games by other commercial developers.", "''Computer Gaming World'' stated that \"a new Olympian in the genre of god games has truly emerged\", comparing ''Civilization'' importance to computer games to that of the wheel.", "The game was reviewed in 1992 in ''Dragon'' #183 by Hartley, Patricia, and Kirk Lesser in \"The Role of Computers\" column.", "The reviewers gave the game 5 out of 5 stars.", "They commented: \"''Civilization'' is one of the highest dollar-to-play-ratio entertainments we've enjoyed.", "The scope is enormous, the strategies border on being limitless, the excitement is genuinely high, and the experience is worth every dime of the game's purchase price.", "\"Jeff Koke reviewed ''Civilization'' in ''Pyramid'' #2 (July/Aug., 1993), and stated that \"Ultimately, there are games that are a lot flashier than ''Civilization'', with cool graphics and animation, but there aren't many - or any - in my book that have the ability to absorb the player so totally and to provide an interesting, unique outcome each and every time it's played.", "\"''Civilization'' won the Origins Award in the category Best Military or Strategy Computer Game of 1991.A 1992 ''Computer Gaming World'' survey of wargames with modern settings gave the game five stars out of five, describing it as \"more addictive than crack ... so rich and textured that the documentation is incomplete\".", "In 1992 the magazine named it the Overall Game of the Year, in 1993 added the game to its Hall of Fame, and in 1996 chose ''Civilization'' as the best game of all time:A critic for ''Next Generation'' judged the Super NES version to be a disappointing port, with a cumbersome menu system (particularly that the \"City\" and \"Production\" windows are on separate screens), an unintuitive button configuration, and ugly scaled down graphics.", "However, he gave it a positive recommendation due to the strong gameplay and strategy of the original game: \"if you've never taken a crack at this game before, be prepared to lose hours, even days, trying to conquer those pesky Babylonians.\"", "Sir Garnabus of ''GamePro'', in contrast, was pleased with the Super NES version's interface, and said the graphics and audio are above that of a typical strategy game.", "He also said the game stood out among the Super NES's generally action-oriented library.In 2000, GameSpot rated ''Civilization'' as the tenth most influential video game of all time.", "It was also ranked at fourth place on ''IGN'' 2000 list of the top PC games of all time.", "In 2004, readers of ''Retro Gamer'' voted it as the 29th top retro game.", "In 2007, it was named one of the 16 most influential games in history at a German technology and games trade show Telespiele.", "In Poland, it was included in the retrospective lists of the best Amiga games by Wirtualna Polska (ranked ninth) and ''CHIP'' (ranked fifth).", "In 2012, ''Time'' named it one of the 100 greatest video games of all time.", "In 1994, ''PC Gamer US'' named ''Civilization'' the second best computer game ever.", "The editors wrote, \"The depth of strategies possible is impressive, and the look and feel of the game will keep you playing and exploring for months.", "Truly a remarkable title.\"", "That same year, ''PC Gamer UK'' named its Windows release the sixth best computer game of all time, calling it Sid Meier's \"crowning glory\".On March 12, 2007, ''The New York Times'' reported on a list of the ten most important video games of all time, the so-called game canon, including ''Civilization''.By the release of ''Civilization II'' in 1996, ''Civilization'' had sold over 850,000 copies.", "By 2001, sales had reached 1 million copies.", "Shelley stated in a 2016 interview that ''Civilization'' had sold 1.5 million copies.In 2022, The Strong National Museum of Play inducted ''Sid Meier’s Civilization'' to its World Video Game Hall of Fame." ], [ "Reviews", "* ''Casus Belli'' #70 (July 1992)" ], [ "Legacy", "There have been several sequels to ''Civilization'', including ''Civilization II'' (1996), ''Civilization III'' (2001), ''Civilization IV'' (2005), ''Civilization Revolution'' (2008), ''Civilization V'' (2010), and ''Civilization VI'' in 2016.In 1994, Meier produced a similar game titled ''Colonization''.", "''Civilization'' is generally considered the first major game in the genre of \"4X\", with the four \"X\"s equating to \"explore, expand, exploit, and exterminate\", a term developed by Alan Emrich in promoting 1993's ''Master of Orion''.", "While other video games with the principles of 4X had been released prior to ''Civilization'', future 4X games would attribute some of their basic design principles to ''Civilization''.A famous supposed bug in the original game - later debunked - is that a computer-controlled Gandhi, normally a highly peaceful leader, could become a nuclear warmonger if provoked.", "It was theorized that the game started Gandhi's \"aggression value\" at 1 out of a maximum 255 possible for an 8-bit unsigned integer, making a computer-controlled Gandhi tend to avoid armed conflict.", "However, once a civilization achieves democracy as its form of government, its leader's aggression value falls by 2.Under normal arithmetic principles, Gandhi's \"1\" would be reduced to \"-1\", but because the value is an 8-bit unsigned integer, it supposedly wraps around to \"255\", causing Gandhi to suddenly become the most aggressive opponent in the game.", "Interviewed in 2019, developer Brian Reynolds said with \"99.99% certainty\" that this story was apocryphal, recalling Gandhi's coded aggression level as being no lower than other peaceful leaders in the game, and doubting that a wraparound would have had the effect described.", "He noted that all leaders in the game become \"pretty ornery\" after their acquisition of nuclear weapons, and suggested that this behaviour simply seemed more surprising and memorable when it happened to Gandhi.", "Meier, in his autobiography, stated \"That kind of bug comes from something called unsigned characters, which are not the default in the C programming language, and not something I used for the leader traits.", "Brian Reynolds wrote Civ II in C++, and he didn't use them, either.", "We received no complaints about a Gandhi bug when either game came out, nor did we send out any revisions for one.", "Gandhi's military aggressiveness score remained at 1 throughout the game.\"", "He then explains the overflow error story was made up in 2012.It spread from there to a Wikia entry, then eventually to Reddit, and was picked up by news sites like Kotaku and Geek.com.", "The story may have originated from the fact that 2010's ''Civilization V'' was deliberately written with Gandhi having an affinity for nuclear weapons, added as a joke by developer Jon Shafer.", "The misinformation around this bug led to the meme known as \"Nuclear Gandhi\".Another relic of ''Civilization'' was the nature of combat where a military unit from earlier civilization periods could remain in play through modern times, gaining combat bonuses due to veteran proficiency, leading to these primitive units easily beating out modern technology against all common sense, with the common example of a veteran phalanx unit able to fend off a battleship.", "Meier noted that this resulted from not anticipating how players would use units, expecting them to have used their forces more like a war-based board game to protect borders and maintain zones of control rather than creating \"stacks of doom\".", "Future civilization games have had many changes in combat systems to prevent such oddities, though these games do allow for such random victories.The 1999 game ''Sid Meier's Alpha Centauri'' was also created by Meier and is in the same genre, but with a futuristic/space theme; many of the interface and gameplay innovations in this game eventually made their way into ''Civilization III'' and ''IV''.", "''Alpha Centauri'' is not actually a sequel to ''Civilization'', despite beginning with the same event that ends ''Civilization'' and ''Civilization II'': a crewed spacecraft from Earth arrives in the Alpha Centauri star system.", "Firaxis' 2014 game ''Civilization: Beyond Earth'', although bearing the name of the main series, is a reimagining of ''Alpha Centauri'' running on the engine of ''Civilization V''.A 1994 ''Computer Gaming World'' survey of space war games stated that \"the lesson of this incredibly popular wargame has not been lost on the software community, and technological research popped up all over the place in 1993\", citing ''Spaceward Ho!''", "and ''Master of Orion'' as examples.", "That year MicroProse published ''Master of Magic'', a similar game but embedded in a medieval-fantasy setting where instead of technologies the player (a powerful wizard) develops spells, among other things.", "In 1999, Activision released ''Civilization: Call to Power'', a sequel of sorts to ''Civilization II'' but created by a completely different design team.", "''Call to Power'' spawned a sequel in 2000, but by then Activision had sold the rights to the ''Civilization'' name and could only call it ''Call to Power II''.An open source clone of ''Civilization'' has been developed under the name of ''Freeciv'', with the slogan \"'Cause civilization should be free.\"", "This game can be configured to match the rules of either ''Civilization'' or ''Civilization II''.", "Another game that partially clones ''Civilization'' is a public domain game called ''C-evo''." ], [ "References", "* ''The Official Guide to Sid Meier's Civilization'', Keith Ferrell, Edmund Ferrell, Compute Books, 1992, .=== Citations ===" ], [ "External links", "* Official website" ] ]
wikipedia
[ [ "Claude Debussy" ], [ "Introduction", "alt=head and shoulders photograph of middle-aged, white, dark-haired, bearded man('''Achille''') '''Claude Debussy''' (;<!--SEE TALK PAGE" ], [ "Life and career", "Rue au Pain, Saint-Germain-en-Laye, street of Debussy's birthplace=== Early life ===Debussy was born on 22 August 1862 in Saint-Germain-en-Laye, Seine-et-Oise, on the north-west fringes of Paris.", "He was the eldest of the five children of Manuel-Achille Debussy and his wife, Victorine, ''née'' Manoury.", "Debussy senior ran a china shop and his wife was a seamstress.", "The shop was unsuccessful, and closed in 1864; the family moved to Paris, first living with Victorine's mother, in Clichy, and, from 1868, in their own apartment in the Rue Saint-Honoré.", "Manuel worked in a printing factory.In 1870, to escape the siege of Paris during the Franco-Prussian War, Debussy's pregnant mother took him and his sister Adèle to their paternal aunt's home in Cannes, where they remained until the following year.", "During his stay in Cannes, the seven-year-old Debussy had his first piano lessons; his aunt paid for him to study with an Italian musician, Jean Cerutti.", "Manuel Debussy remained in Paris and joined the forces of the Commune; after its defeat by French government troops in 1871 he was sentenced to four years' imprisonment, of which he only served one year.", "His fellow Communard prisoners included his friend Charles de Sivry, a musician.", "Sivry's mother, Antoinette Mauté de Fleurville, gave piano lessons, and at his instigation the young Debussy became one of her pupils.Debussy's talents soon became evident, and in 1872, aged ten, he was admitted to the Conservatoire de Paris, where he remained a student for the next eleven years.", "He first joined the piano class of Antoine François Marmontel, and studied solfège with Albert Lavignac and, later, composition with Ernest Guiraud, harmony with Émile Durand, and organ with César Franck.", "The course included music history and theory studies with Louis-Albert Bourgault-Ducoudray, but it is not certain that Debussy, who was apt to skip classes, actually attended these.At the Conservatoire, Debussy initially made good progress.", "Marmontel said of him, \"A charming child, a truly artistic temperament; much can be expected of him\".", "Another teacher was less impressed: Émile Durand wrote in a report, \"Debussy would be an excellent pupil if he were less sketchy and less cavalier.\"", "A year later he described Debussy as \"desperately careless\".", "In July 1874 Debussy received the award of ''deuxième accessit'' for his performance as soloist in the first movement of Chopin's Second Piano Concerto at the Conservatoire's annual competition.", "He was a fine pianist and an outstanding sight reader, who could have had a professional career had he wished, but he was only intermittently diligent in his studies.", "He advanced to ''premier accessit'' in 1875 and second prize in 1877, but failed at the competitions in 1878 and 1879.These failures made him ineligible to continue in the Conservatoire's piano classes, but he remained a student for harmony, solfège and, later, composition.With Marmontel's help Debussy secured a summer vacation job in 1879 as resident pianist at the Château de Chenonceau, where he rapidly acquired a taste for luxury that was to remain with him all his life.", "His first compositions date from this period, two settings of poems by Alfred de Musset: \"Ballade à la lune\" and \"Madrid, princesse des Espagnes\".", "The following year he secured a job as pianist in the household of Nadezhda von Meck, the patroness of Tchaikovsky.", "He travelled with her family for the summers of 1880 to 1882, staying at various places in France, Switzerland and Italy, as well as at her home in Moscow.", "He composed his Piano Trio in G major for von Meck's ensemble, and made a transcription for piano duet of three dances from Tchaikovsky's ''Swan Lake''.=== Prix de Rome ===Debussy by Marcel Baschet, 1884At the end of 1880 Debussy, while continuing his studies at the Conservatoire, was engaged as accompanist for Marie Moreau-Sainti's singing class; he took this role for four years.", "Among the members of the class was Marie Vasnier; Debussy was greatly taken with her, and she inspired him to compose: he wrote 27 songs dedicated to her during their seven-year relationship.", "She was the wife of Henri Vasnier, a prominent civil servant, and much younger than her husband.", "She soon became Debussy's lover as well as his muse.", "Whether Vasnier was content to tolerate his wife's affair with the young student or was simply unaware of it is not clear, but he and Debussy remained on excellent terms, and he continued to encourage the composer in his career.At the Conservatoire, Debussy incurred the disapproval of the faculty, particularly his composition teacher, Guiraud, for his failure to follow the orthodox rules of composition then prevailing.", "Nevertheless, in 1884 Debussy won France's most prestigious musical award, the Prix de Rome, with his cantata ''L'enfant prodigue''.", "The Prix carried with it a residence at the Villa Medici, the French Academy in Rome, to further the winner's studies.", "Debussy was there from January 1885 to March 1887, with three or possibly four absences of several weeks when he returned to France, chiefly to see Marie Vasnier.Initially Debussy found the artistic atmosphere of the Villa Medici stifling, the company boorish, the food bad, and the accommodation \"abominable\".", "Neither did he delight in Italian opera, as he found the operas of Donizetti and Verdi not to his taste.", "He was much more impressed by the music of the 16th-century composers Palestrina and Lassus, which he heard at Santa Maria dell'Anima: \"The only church music I will accept\".", "He was often depressed and unable to compose, but he was inspired by Franz Liszt, who visited the students and played for them.", "In June 1885, Debussy wrote of his desire to follow his own way, saying, \"I am sure the Institute would not approve, for, naturally it regards the path which it ordains as the only right one.", "But there is no help for it!", "I am too enamoured of my freedom, too fond of my own ideas!", "\"Debussy finally composed four pieces that were submitted to the Academy: the symphonic ode ''Zuleima'' (based on a text by Heinrich Heine); the orchestral piece ''Printemps''; the cantata ''La Damoiselle élue'' (1887–1888), the first piece in which the stylistic features of his later music began to emerge; and the ''Fantaisie'' for piano and orchestra, which was heavily based on Franck's music and was eventually withdrawn by Debussy.", "The Academy chided him for writing music that was \"bizarre, incomprehensible and unperformable\".", "Although Debussy's works showed the influence of Jules Massenet, the latter concluded, \"He is an enigma\".", "During his years in Rome Debussy composed – not for the Academy – most of his Verlaine cycle, ''Ariettes oubliées'', which made little impact at the time but was successfully republished in 1903 after the composer had become well known.=== Return to Paris, 1887 ===A week after his return to Paris in 1887, Debussy heard the first act of Wagner's ''Tristan und Isolde'' at the Concerts Lamoureux, and judged it \"decidedly the finest thing I know\".", "In 1888 and 1889 he went to the annual festivals of Wagner's operas at Bayreuth.", "He responded positively to Wagner's sensuousness, mastery of form, and striking harmonies, and was briefly influenced by them, but, unlike some other French composers of his generation, he concluded that there was no future in attempting to adopt and develop Wagner's style.", "He commented in 1903 that Wagner was \"a beautiful sunset that was mistaken for a dawn\".Gamelan orchestra, In 1889, at the Paris Exposition Universelle, Debussy first heard Javanese gamelan music.", "The gamelan scales, melodies, rhythms, and ensemble textures appealed to him, and echoes of them are heard in \"Pagodes\" in his piano suite ''Estampes''.", "He also attended two concerts of Rimsky-Korsakov's music, conducted by the composer.", "This too made an impression on him, and its harmonic freedom and non-Teutonic tone colours influenced his own developing musical style.Marie Vasnier ended her liaison with Debussy soon after his final return from Rome, although they remained on good enough terms for him to dedicate to her one more song, \"Mandoline\", in 1890.Later in 1890 Debussy met Erik Satie, who proved a kindred spirit in his experimental approach to composition.", "Both were bohemians, enjoying the same café society and struggling to survive financially.", "In the same year Debussy began a relationship with Gabrielle (Gaby) Dupont, a tailor's daughter from Lisieux; in July 1893 they began living together.Debussy continued to compose songs, piano pieces and other works, some of which were publicly performed, but his music made only a modest impact, although his fellow composers recognised his potential by electing him to the committee of the Société Nationale de Musique in 1893.His String Quartet was premiered by the Ysaÿe string quartet at the Société Nationale in the same year.", "In May 1893 Debussy attended a theatrical event that was of key importance to his later career – the premiere of Maurice Maeterlinck's play ''Pelléas et Mélisande'', which he immediately determined to turn into an opera.", "He travelled to Maeterlinck's home in Ghent in November to secure his consent to an operatic adaptation.=== 1894–1902: ''Pelléas et Mélisande'' ===Lilly Debussy in 1902In February 1894 Debussy completed the first draft of Act I of his operatic version of ''Pelléas et Mélisande'', and for most of the year worked to complete the work.", "While still living with Dupont, he had an affair with the singer Thérèse Roger, and in 1894 he announced their engagement.", "His behaviour was widely condemned; anonymous letters circulated denouncing his treatment of both women, as well as his financial irresponsibility and debts.", "The engagement was broken off, and several of Debussy's friends and supporters disowned him, including Ernest Chausson, hitherto one of his strongest supporters.In terms of musical recognition, Debussy made a step forward in December 1894, when the symphonic poem ''Prélude à l'après-midi d'un faune'', based on Stéphane Mallarmé's poem, was premiered at a concert of the Société Nationale.", "The following year he completed the first draft of ''Pelléas'' and began efforts to get it staged.", "In May 1898 he made his first contacts with André Messager and Albert Carré, respectively the musical director and general manager of the Opéra-Comique, Paris, about presenting the opera.Poster by Georges Rochegrosse for the premiere of ''Pelléas et Mélisande'' (1902).Debussy abandoned Dupont for her friend Marie-Rosalie Texier, known as \"Lilly\", whom he married in October 1899, after threatening suicide if she refused him.", "She was affectionate, practical, straightforward, and well liked by Debussy's friends and associates, but he became increasingly irritated by her intellectual limitations and lack of musical sensitivity.", "The marriage lasted barely five years.From around 1900 Debussy's music became a focus and inspiration for an informal group of innovative young artists, poets, critics, and musicians who began meeting in Paris.", "They called themselves ''Les Apaches'' – roughly \"The Hooligans\" – to represent their status as \"artistic outcasts\".", "The membership was fluid, but at various times included Maurice Ravel, Ricardo Viñes, Igor Stravinsky and Manuel de Falla.", "In the same year the first two of Debussy's three orchestral ''Nocturnes'' were first performed.", "Although they did not make any great impact with the public they were well reviewed by musicians including Paul Dukas, Alfred Bruneau and Pierre de Bréville.", "The complete set was given the following year.Like many other composers of the time, Debussy supplemented his income by teaching and writing.", "For most of 1901 he had a sideline as music critic of ''La Revue Blanche'', adopting the pen name \"Monsieur Croche\".", "He expressed trenchant views on composers (\"I hate sentimentality – his name is Camille Saint-Saëns\"), institutions (on the Paris Opéra: \"A stranger would take it for a railway station, and, once inside, would mistake it for a Turkish bath\"), conductors (\"Nikisch is a unique virtuoso, so much so that his virtuosity seems to make him forget the claims of good taste\"), musical politics (\"The English actually think that a musician can manage an opera house successfully!", "\"), and audiences (\"their almost drugged expression of boredom, indifference and even stupidity\").", "He later collected his criticisms with a view to their publication as a book; it was published after his death as ''Monsieur Croche, Antidilettante''.In January 1902 rehearsals began at the Opéra-Comique for the opening of ''Pelléas et Mélisande''.", "For three months, Debussy attended rehearsals practically every day.", "In February there was conflict between Maeterlinck on the one hand and Debussy, Messager and Carré on the other about the casting of Mélisande.", "Maeterlinck wanted his mistress, Georgette Leblanc, to sing the role, and was incensed when she was passed over in favour of the Scottish soprano Mary Garden.", "The opera opened on 30 April 1902, and although the first-night audience was divided between admirers and sceptics, the work quickly became a success.", "It made Debussy a well-known name in France and abroad; ''The Times'' commented that the opera had \"provoked more discussion than any work of modern times, excepting, of course, those of Richard Strauss\".", "The Apaches, led by Ravel (who attended every one of the 14 performances in the first run), were loud in their support; the conservative faculty of the Conservatoire tried in vain to stop its students from seeing the opera.", "The vocal score was published in early May, and the full orchestral score in 1904.=== 1903–1918 ===Emma Bardac (later Emma Debussy) in 1903In 1903 there was public recognition of Debussy's stature when he was appointed a Chevalier of the Légion d'honneur, but his social standing suffered a great blow when another turn in his private life caused a scandal the following year.", "One of his pupils was Raoul Bardac, son of Emma and her husband, Parisian banker Sigismond Bardac.", "Raoul introduced his teacher to his mother, to whom Debussy quickly became greatly attracted.", "She was sophisticated, a brilliant conversationalist, an accomplished singer, and relaxed about marital fidelity, having been the mistress and muse of Gabriel Fauré a few years earlier.", "After despatching Lilly to her parental home at Bichain in Villeneuve-la-Guyard on 15 July 1904, Debussy took Emma away, staying incognito in Jersey and then at Pourville in Normandy.", "He wrote to his wife on 11 August from Dieppe, telling her that their marriage was over, but still making no mention of Bardac.", "When he returned to Paris he set up home on his own, taking a flat in a different arrondissement.", "On 14 October, five days before their fifth wedding anniversary, Lilly Debussy attempted suicide, shooting herself in the chest with a revolver; she survived, although the bullet remained lodged in her vertebrae for the rest of her life.", "The ensuing scandal caused Bardac's family to disown her, and Debussy lost many good friends including Dukas and Messager.", "His relations with Ravel, never close, were exacerbated when the latter joined other former friends of Debussy in contributing to a fund to support the deserted Lilly.The Bardacs divorced in May 1905.Finding the hostility in Paris intolerable, Debussy and Emma (now pregnant) went to England.", "They stayed at the Grand Hotel, Eastbourne in July and August, where Debussy corrected the proofs of his symphonic sketches'' La mer'', celebrating his divorce on 2 August.", "After a brief visit to London, the couple returned to Paris in September, buying a house in a courtyard development off the Avenue du Bois de Boulogne (now Avenue Foch), Debussy's home for the rest of his life.Debussy's last home, now 23 Square de l'Avenue Foch, ParisIn October 1905 ''La mer'', Debussy's most substantial orchestral work, was premiered in Paris by the Orchestre Lamoureux under the direction of Camille Chevillard; the reception was mixed.", "Some praised the work, but Pierre Lalo, critic of ''Le Temps'', hitherto an admirer of Debussy, wrote, \"I do not hear, I do not see, I do not smell the sea\".", "In the same month the composer's only child was born at their home.", "Claude-Emma, affectionately known as \"Chouchou\", was a musical inspiration to the composer (she was the dedicatee of his ''Children's Corner'' suite).", "She outlived her father by scarcely a year, succumbing to the diphtheria epidemic of 1919.Mary Garden said, \"I honestly don't know if Debussy ever loved anybody really.", "He loved his music – and perhaps himself.", "I think he was wrapped up in his genius\", but biographers are agreed that whatever his relations with lovers and friends, Debussy was devoted to his daughter.Debussy and Emma Bardac eventually married in 1908, their troubled union enduring for the rest of his life.", "The following year began well, when at Fauré's invitation, Debussy became a member of the governing council of the Conservatoire.", "His success in London was consolidated in April 1909, when he conducted ''Prélude à l'après-midi d'un faune'' and the ''Nocturnes'' at the Queen's Hall; in May he was present at the first London production of ''Pelléas et Mélisande'', at Covent Garden.", "In the same year, Debussy was diagnosed with colorectal cancer, from which he was to die nine years later.Debussy's works began to feature increasingly in concert programmes at home and overseas.", "In 1910 Gustav Mahler conducted the ''Nocturnes'' and ''Prélude à l'après-midi d'un faune'' in New York in successive months.", "In the same year, visiting Budapest, Debussy commented that his works were better known there than in Paris.", "In 1912 Sergei Diaghilev commissioned a new ballet score, ''Jeux''.", "That, and the three ''Images'', premiered the following year, were the composer's last orchestral works.", "''Jeux'' was unfortunate in its timing: two weeks after the premiere, in March 1913, Diaghilev presented the first performance of Stravinsky's ''The Rite of Spring'', a sensational event that monopolised discussion in musical circles, and effectively sidelined ''Jeux'' along with Fauré's ''Pénélope'', which had opened a week before.Debussy in 1908In 1915 Debussy underwent one of the earliest colostomy operations.", "It achieved only a temporary respite, and occasioned him considerable frustration (\"There are mornings when the effort of dressing seems like one of the twelve labours of Hercules\").", "He also had a fierce enemy at this period in the form of Camille Saint-Saëns, who in a letter to Fauré condemned Debussy's ''En blanc et noir'': \"It's incredible, and the door of the Institut de France must at all costs be barred against a man capable of such atrocities\".", "Saint-Saëns had been a member of the Institut since 1881: Debussy never became one.", "His health continued to decline; he gave his final concert on 14 September 1917 and became bedridden in early 1918.Debussy died on 25 March 1918 at his home.", "The First World War was still raging and Paris was under German aerial and artillery bombardment.", "The military situation did not permit the honour of a public funeral with ceremonious graveside orations.", "The funeral procession made its way through deserted streets to a temporary grave at Père Lachaise Cemetery as the German guns bombarded the city.", "Debussy's body was reinterred the following year in the small Passy Cemetery sequestered behind the Trocadéro, fulfilling his wish to rest \"among the trees and the birds\"; his wife and daughter are buried with him." ], [ "Works", "In a survey of Debussy's oeuvre shortly after the composer's death, the critic Ernest Newman wrote, \"It would be hardly too much to say that Debussy spent a third of his life in the discovery of himself, a third in the free and happy realisation of himself, and the final third in the partial, painful loss of himself\".", "Later commentators have rated some of the late works more highly than Newman and other contemporaries did, but much of the music for which Debussy is best known is from the middle years of his career.The analyst David Cox wrote in 1974 that Debussy, admiring Wagner's attempts to combine all the creative arts, \"created a new, instinctive, dreamlike world of music, lyrical and pantheistic, contemplative and objective – a kind of art, in fact, which seemed to reach out into all aspects of experience\".", "In 1988 the composer and scholar Wilfrid Mellers wrote of Debussy:Debussy did not give his works opus numbers, apart from his String Quartet, Op.", "10 in G minor (also the only work where the composer's title included a key).", "His works were catalogued and indexed by the musicologist François Lesure in 1977 (revised in 2003) and their Lesure number (\"L\" followed by a number) is sometimes used as a suffix to their title in concert programmes and recordings.=== Early works, 1879–1892 ===Debussy's musical development was slow, and as a student he was adept enough to produce for his teachers at the Conservatoire works that would conform to their conservative precepts.", "His friend Georges Jean-Aubry commented that Debussy \"admirably imitated Massenet's melodic turns of phrase\" in the cantata ''L'enfant prodigue'' (1884) which won him the Prix de Rome.", "A more characteristically Debussian work from his early years is ''La Damoiselle élue'', recasting the traditional form for oratorios and cantatas, using a chamber orchestra and a small body of choral tone and using new or long-neglected scales and harmonies.", "His early ''mélodies'', inspired by Marie Vasnier, are more virtuosic in character than his later works in the genre, with extensive wordless ''vocalise''; from the ''Ariettes oubliées'' (1885–1887) onwards he developed a more restrained style.", "He wrote his own poems for the ''Proses lyriques'' (1892–1893) but, in the view of the musical scholar Robert Orledge, \"his literary talents were not on a par with his musical imagination\".The musicologist Jacques-Gabriel Prod'homme wrote that, together with ''La Demoiselle élue'', the ''Ariettes oubliées'' and the ''Cinq poèmes de Charles Baudelaire'' (1889) show \"the new, strange way which the young musician will hereafter follow\".", "Newman concurred: \"There is a good deal of Wagner, especially of ''Tristan'', in the idiom.", "But the work as a whole is distinctive, and the first in which we get a hint of the Debussy we were to know later – the lover of vague outlines, of half-lights, of mysterious consonances and dissonances of colour, the apostle of languor, the exclusivist in thought and in style.\"", "During the next few years Debussy developed his personal style, without, at this stage, breaking sharply away from French musical traditions.", "Much of his music from this period is on a small scale, such as the ''Two Arabesques'', ''Valse romantique'', ''Suite bergamasque'', and the first set of ''Fêtes galantes''.", "Newman remarked that, like Chopin, the Debussy of this period appears as a liberator from Germanic styles of composition – offering instead \"an exquisite, pellucid style\" capable of conveying \"not only gaiety and whimsicality but emotion of a deeper sort\".", "In a 2004 study, Mark DeVoto comments that Debussy's early works are harmonically no more adventurous than existing music by Fauré; in a 2007 book about the piano works, Margery Halford observes that ''Two Arabesques'' (1888–1891) and \"Rêverie\" (1890) have \"the fluidity and warmth of Debussy's later style\" but are not harmonically innovative.", "Halford cites the popular \"Clair de Lune\" (1890), the third of the four movements of ''Suite Bergamasque'', as a transitional work pointing towards the composer's mature style.=== Middle works, 1893–1905 ===L'après-midi d'un faune'', 1910Musicians from Debussy's time onwards have regarded ''Prélude à l'après-midi d'un faune'' (1894) as his first orchestral masterpiece.", "Newman considered it \"completely original in idea, absolutely personal in style, and logical and coherent from first to last, without a superfluous bar or even a superfluous note\"; Pierre Boulez observed, \"Modern music was awakened by ''Prélude à l'après-midi d'un faune''\".", "Most of the major works for which Debussy is best known were written between the mid-1890s and the mid-1900s.", "They include the String Quartet (1893), ''Pelléas et Mélisande'' (1893–1902), the ''Nocturnes for Orchestra'' (1899) and ''La mer'' (1903–1905).", "The suite ''Pour le piano'' (1894–1901) is, in Halford's view, one of the first examples of the mature Debussy as a composer for the piano: \"a major landmark ... and an enlargement of the use of piano sonorities\".In the String Quartet (1893), the gamelan sonorities Debussy had heard four years earlier are recalled in the pizzicatos and cross-rhythms of the scherzo.", "Debussy's biographer Edward Lockspeiser comments that this movement shows the composer's rejection of \"the traditional dictum that string instruments should be predominantly lyrical\".", "The work influenced Ravel, whose own String Quartet, written ten years later, has noticeably Debussian features.", "The academic and journalist Stephen Walsh calls ''Pelléas et Mélisande'' (begun 1893, staged 1902) \"a key work for the 20th century\".", "The composer Olivier Messiaen was fascinated by its \"extraordinary harmonic qualities and ... transparent instrumental texture\".", "The opera is composed in what Alan Blyth describes as a sustained and heightened recitative style, with \"sensuous, intimate\" vocal lines.", "It influenced composers as different as Stravinsky and Puccini.Orledge describes the ''Nocturnes'' as exceptionally varied in texture, \"ranging from the Musorgskian start of 'Nuages', through the approaching brass band procession in 'Fêtes', to the wordless female chorus in 'Sirènes.", "Orledge considers the last a pre-echo of the marine textures of ''La mer''.", "''Estampes'' for piano (1903) gives impressions of exotic locations, with further echoes of the gamelan in its pentatonic structures.", "Debussy believed that since Beethoven, the traditional symphonic form had become formulaic, repetitive and obsolete.", "The three-part, cyclic symphony by César Franck (1888) was more to his liking, and its influence can be found in ''La mer'' (1905); this uses a quasi-symphonic form, its three sections making up a giant sonata-form movement with, as Orledge observes, a cyclic theme, in the manner of Franck.", "The central \"Jeux de vagues\" section has the function of a symphonic development section leading into the final \"Dialogue du vent et de la mer\", \"a powerful essay in orchestral colour and sonority\" (Orledge) which reworks themes from the first movement.", "The reviews were sharply divided.", "Some critics thought the treatment less subtle and less mysterious than his previous works, and even a step backward; others praised its \"power and charm\", its \"extraordinary verve and brilliant fantasy\", and its strong colours and definite lines.=== Late works, 1906–1917 ===Of the later orchestral works, ''Images'' (1905–1912) is better known than ''Jeux'' (1913).", "The former follows the tripartite form established in the ''Nocturnes'' and ''La mer'', but differs in employing traditional British and French folk tunes, and in making the central movement, \"Ibéria\", far longer than the outer ones, and subdividing it into three parts, all inspired by scenes from Spanish life.", "Although considering ''Images'' \"the pinnacle of Debussy's achievement as a composer for orchestra\", Trezise notes a contrary view that the accolade belongs to the ballet score ''Jeux''.", "The latter failed as a ballet because of what Jann Pasler describes as a banal scenario, and the score was neglected for some years.", "Recent analysts have found it a link between traditional continuity and thematic growth within a score and the desire to create discontinuity in a way mirrored in later 20th century music.", "In this piece, Debussy abandoned the whole-tone scale he had often favoured previously in favour of the octatonic scale with what the Debussy scholar François Lesure describes as its tonal ambiguities.Among the late piano works are two books of ''Préludes'' (1909–10, 1911–13), short pieces that depict a wide range of subjects.", "Lesure comments that they range from the frolics of minstrels at Eastbourne in 1905 and the American acrobat \"General Lavine\" \"to dead leaves and the sounds and scents of the evening air\".", "''En blanc et noir'' (In white and black, 1915), a three-movement work for two pianos, is a predominantly sombre piece, reflecting the war and national danger.", "The ''Études'' (1915) for piano have divided opinion.", "Writing soon after Debussy's death, Newman found them laboured – \"a strange last chapter in a great artist's life\"; Lesure, writing eighty years later, rates them among Debussy's greatest late works: \"Behind a pedagogic exterior, these 12 pieces explore abstract intervals, or – in the last five – the sonorities and timbres peculiar to the piano.\"", "In 1914 Debussy started work on a planned set of six sonatas for various instruments.", "His fatal illness prevented him from completing the set, but those for cello and piano (1915), flute, viola and harp (1915), and violin and piano (1917 – his last completed work) are all concise, three-movement pieces, more diatonic in nature than some of his other late works.", "''Le Martyre de saint Sébastien'' (1911), originally a five-act musical play to a text by Gabriele D'Annunzio that took nearly five hours in performance, was not a success, and the music is now more often heard in a concert (or studio) adaptation with narrator, or as an orchestral suite of \"Fragments symphoniques\".", "Debussy enlisted the help of André Caplet in orchestrating and arranging the score.", "Two late stage works, the ballets ''Khamma'' (1912) and ''La boîte à joujoux'' (1913), were left with the orchestration incomplete, and were completed by Charles Koechlin and Caplet, respectively." ], [ "Style", "=== Debussy and Impressionism ===Monet's ''Impression, soleil levant'' (1872), from which \"Impressionism\" takes its nameThe application of the term \"Impressionist\" to Debussy and the music he influenced has been much debated, both during his lifetime and since.", "The analyst Richard Langham Smith writes that Impressionism was originally a term coined to describe a style of late 19th-century French painting, typically scenes suffused with reflected light in which the emphasis is on the overall impression rather than outline or clarity of detail, as in works by Monet, Pissarro, Renoir and others.", "Langham Smith writes that the term became transferred to the compositions of Debussy and others which were \"concerned with the representation of landscape or natural phenomena, particularly the water and light imagery dear to Impressionists, through subtle textures suffused with instrumental colour\".Among painters, Debussy particularly admired Turner, but also drew inspiration from Whistler.", "With the latter in mind the composer wrote to the violinist Eugène Ysaÿe in 1894 describing the orchestral ''Nocturnes'' as \"an experiment in the different combinations that can be obtained from one colour – what a study in grey would be in painting.", "\"Debussy strongly objected to the use of the word \"Impressionism\" for his (or anybody else's) music, but it has continually been attached to him since the assessors at the Conservatoire first applied it, opprobriously, to his early work ''Printemps''.", "Langham Smith comments that Debussy wrote many piano pieces with titles evocative of nature – \"Reflets dans l'eau\" (1905), \"Les Sons et les parfums tournent dans l'air du soir\" (1910) and \"Brouillards\" (1913) – and suggests that the Impressionist painters' use of brush-strokes and dots is paralleled in the music of Debussy.", "Although Debussy said that anyone using the term (whether about painting or music) was an imbecile, some Debussy scholars have taken a less absolutist line.", "Lockspeiser calls ''La mer'' \"the greatest example of an orchestral Impressionist work\", and more recently in ''The Cambridge Companion to Debussy'' Nigel Simeone comments, \"It does not seem unduly far-fetched to see a parallel in Monet's seascapes\".In this context may be placed Debussy's pantheistic eulogy to Nature, in a 1911 interview with Henry Malherbe:In contrast to the \"impressionistic\" characterisation of Debussy's music, several writers have suggested that he structured at least some of his music on rigorous mathematical lines.", "In 1983 the pianist and scholar Roy Howat published a book contending that certain of Debussy's works are proportioned using mathematical models, even while using an apparent classical structure such as sonata form.", "Howat suggests that some of Debussy's pieces can be divided into sections that reflect the golden ratio, which is approximated by ratios of consecutive numbers in the Fibonacci sequence.", "Simon Trezise, in his 1994 book ''Debussy: La Mer'', finds the intrinsic evidence \"remarkable\", with the caveat that no written or reported evidence suggests that Debussy deliberately sought such proportions.", "Lesure takes a similar view, endorsing Howat's conclusions while not taking a view on Debussy's conscious intentions.=== Musical idiom ===Improvised chord sequences played by Debussy for Guiraud Chords from dialogue with Ernest GuiraudDebussy wrote \"We must agree that the beauty of a work of art will always remain a mystery ... we can never be absolutely sure 'how it's made.'", "We must at all costs preserve this magic which is peculiar to music and to which music, by its nature, is of all the arts the most receptive.", "\"Nevertheless, there are many indicators of the sources and elements of Debussy's idiom.", "Writing in 1958, the critic Rudolph Reti summarised six features of Debussy's music, which he asserted \"established a new concept of tonality in European music\": the frequent use of lengthy pedal points – \"not merely bass pedals in the actual sense of the term, but sustained 'pedals' in any voice\"; glittering passages and webs of figurations which distract from occasional absence of tonality; frequent use of parallel chords which are \"in essence not harmonies at all, but rather 'chordal melodies', enriched unisons\", described by some writers as non-functional harmonies; bitonality, or at least bitonal chords; use of the whole-tone and pentatonic scales; and unprepared modulations, \"without any harmonic bridge\".", "Reti concludes that Debussy's achievement was the synthesis of monophonic based \"melodic tonality\" with harmonies, albeit different from those of \"harmonic tonality\".In 1889, Debussy held conversations with his former teacher Guiraud, which included exploration of harmonic possibilities at the piano.", "The discussion, and Debussy's chordal keyboard improvisations, were noted by a younger pupil of Guiraud, Maurice Emmanuel.", "The chord sequences played by Debussy include some of the elements identified by Reti.", "They may also indicate the influence on Debussy of Satie's 1887 ''Trois Sarabandes''.", "A further improvisation by Debussy during this conversation included a sequence of whole tone harmonies which may have been inspired by the music of Glinka or Rimsky-Korsakov which was becoming known in Paris at this time.", "During the conversation, Debussy told Guiraud, \"There is no theory.", "You have only to listen.", "Pleasure is the law!\"", "– although he also conceded, \"I feel free because I have been through the mill, and I don't write in the fugal style because I know it.\"" ], [ "Influences", "=== Musical ===Among French predecessors, Chabrier was an important influence on Debussy (as he was on Ravel and Poulenc); Howat has written that Chabrier's piano music such as \"Sous-bois\" and \"Mauresque\" in the ''Pièces pittoresques'' explored new sound-worlds of which Debussy made effective use 30 years later.", "Lesure finds traces of Gounod and Massenet in some of Debussy's early songs, and remarks that it may have been from the Russians – Tchaikovsky, Balakirev, Rimsky-Korsakov, Borodin and Mussorgsky – that Debussy acquired his taste for \"ancient and oriental modes and for vivid colorations, and a certain disdain for academic rules\".", "Lesure also considers that Mussorgsky's opera ''Boris Godunov'' directly influenced Debussy's ''Pelléas et Mélisande''.", "In the music of Palestrina, Debussy found what he called \"a perfect whiteness\", and he felt that although Palestrina's musical forms had a \"strict manner\", they were more to his taste than the rigid rules prevailing among 19th-century French composers and teachers.", "He drew inspiration from what he called Palestrina's \"harmony created by melody\", finding an arabesque-like quality in the melodic lines.Debussy opined that Chopin was \"the greatest of them all, for through the piano he discovered everything\"; he professed his \"respectful gratitude\" for Chopin's piano music.", "He was torn between dedicating his own Études to Chopin or to François Couperin, whom he also admired as a model of form, seeing himself as heir to their mastery of the genre.", "Howat cautions against the assumption that Debussy's Ballade (1891) and Nocturne (1892) are influenced by Chopin – in Howat's view they owe more to Debussy's early Russian models – but Chopin's influence is found in other early works such as the ''Two arabesques'' (1889–1891).", "In 1914 the publisher A. Durand & fils began publishing scholarly new editions of the works of major composers, and Debussy undertook the supervision of the editing of Chopin's music.Although Debussy was in no doubt of Wagner's stature, he was only briefly influenced by him in his compositions, after ''La damoiselle élue'' and the ''Cinq poèmes de Baudelaire'' (both begun in 1887).", "According to Pierre Louÿs, Debussy \"did not see 'what anyone can do beyond Tristan',\" although he admitted that it was sometimes difficult to avoid \"the ghost of old Klingsor, alias Richard Wagner, appearing at the turning of a bar\".", "After Debussy's short Wagnerian phase, he started to become interested in non-Western music and its unfamiliar approaches to composition.", "The piano piece ''Golliwogg's Cakewalk'', from the 1908 suite ''Children's Corner'', contains a parody of music from the introduction to ''Tristan'', in which, in the opinion of the musicologist Lawrence Kramer, Debussy escapes the shadow of the older composer and \"smilingly relativizes Wagner into insignificance\".A contemporary influence was Erik Satie, according to Nichols Debussy's \"most faithful friend\" amongst French musicians.", "Debussy's orchestration in 1896 of Satie's ''Gymnopédies'' (which had been written in 1887) \"put their composer on the map\" according to the musicologist Richard Taruskin, and the Sarabande from Debussy's ''Pour le piano'' (1901) \"shows that Debussy knew Satie's ''Trois Sarabandes'' at a time when only a personal friend of the composer could have known them.\"", "(They were not published until 1911).", "Debussy's interest in the popular music of his time is evidenced not only by the ''Golliwogg's Cakewalk'' and other piano pieces featuring rag-time, such as ''The Little Nigar'' (Debussy's spelling) (1909), but by the slow waltz ''La plus que lente'' (''The more than slow''), based on the style of the gipsy violinist at a Paris hotel (to whom he gave the manuscript of the piece).In addition to the composers who influenced his own compositions, Debussy held strong views about several others.", "He was for the most part enthusiastic about Richard Strauss and Stravinsky, respectful of Mozart and was in awe of Bach, whom he called the \"good God of music\" ().", "His relationship to Beethoven was complex; he was said to refer to him as ('the old deaf one') and asked one young pupil not to play Beethoven's music for \"it is like somebody dancing on my grave;\" but he believed that Beethoven had profound things to say, yet did not know how to say them, \"because he was imprisoned in a web of incessant restatement and of German aggressiveness.\"", "He was not in sympathy with Schubert, Schumann, Brahms and Mendelssohn, the latter being described as a \"facile and elegant notary\".With the advent of the First World War, Debussy became ardently patriotic in his musical opinions.", "Writing to Stravinsky, he asked \"How could we not have foreseen that these men were plotting the destruction of our art, just as they had planned the destruction of our country?\"", "In 1915 he complained that \"since Rameau we have had no purely French tradition ... We tolerated overblown orchestras, tortuous forms ... we were about to give the seal of approval to even more suspect naturalizations when the sound of gunfire put a sudden stop to it all.\"", "Taruskin writes that some have seen this as a reference to the composers Gustav Mahler and Arnold Schoenberg, both born Jewish.", "In 1912 Debussy had remarked to his publisher of the opera ''Ariane et Barbe-bleue'' by the (also Jewish) composer Paul Dukas, \"You're right, it is a masterpiece – but it's not a masterpiece of French music.", "\"=== Literary ===S.", "Pickwick Esq.", "P.P.M.P.C.Despite his lack of formal schooling, Debussy read widely and found inspiration in literature.", "Lesure writes, \"The development of free verse in poetry and the disappearance of the subject or model in painting influenced him to think about issues of musical form.\"", "Debussy was influenced by the Symbolist poets.", "These writers, who included Verlaine, Mallarmé, Maeterlinck and Rimbaud, reacted against the realism, naturalism, objectivity and formal conservatism that prevailed in the 1870s.", "They favoured poetry using suggestion rather than direct statement; the literary scholar Chris Baldrick writes that they evoked \"subjective moods through the use of private symbols, while avoiding the description of external reality or the expression of opinion\".", "Debussy was much in sympathy with the Symbolists' desire to bring poetry closer to music, became friendly with several leading exponents, and set many Symbolist works throughout his career.Debussy's literary inspirations were mostly French, but he did not overlook foreign writers.", "As well as Maeterlinck for ''Pelléas et Mélisande'', he drew on Shakespeare and Dickens for two of his Préludes for piano – ''La Danse de Puck'' (Book 1, 1910) and ''Hommage à S. Pickwick Esq.", "P.P.M.P.C.''", "(Book 2, 1913).", "He set Dante Gabriel Rossetti's ''The Blessed Damozel'' in his early cantata, ''La Damoiselle élue'' (1888).", "He wrote incidental music for ''King Lear'' and planned an opera based on ''As You Like It'', but abandoned that once he turned his attention to setting Maeterlinck's play.", "In 1890 he began work on an orchestral piece inspired by Edgar Allan Poe's ''The Fall of the House of Usher'' and later sketched the libretto for an opera, ''La chute de la maison Usher''.", "Another project inspired by Poe – an operatic version of ''The Devil in the Belfry'' did not progress beyond sketches.", "French writers whose words he set include Paul Bourget, Alfred de Musset, Théodore de Banville, Leconte de Lisle, Théophile Gautier, Paul Verlaine, François Villon, and Mallarmé – the last of whom also provided Debussy with the inspiration for one of his most popular orchestral pieces, ''Prélude à l'après-midi d'un faune''." ], [ "Influence on later composers", "alt= two white men, one bearded, middle-aged, standing, one younger, seated, in a book-lined roomDebussy is widely regarded as one of the most influential composers of the 20th century.", "Roger Nichols writes that \"if one omits Schoenberg ... a list of 20th-century composers influenced by Debussy is practically a list of 20th-century composers ''tout court''.", "\"Bartók first encountered Debussy's music in 1907 and later said that \"Debussy's great service to music was to reawaken among all musicians an awareness of harmony and its possibilities\".", "Not only Debussy's use of whole-tone scales, but also his style of word-setting in ''Pelléas et Mélisande'', were the subject of study by Leoš Janáček while he was writing his 1921 opera ''Káťa Kabanová''.", "Stravinsky was more ambivalent about Debussy's music (he thought ''Pelléas'' \"a terrible bore ... in spite of many wonderful pages\") but the two composers knew each other and Stravinsky's ''Symphonies of Wind Instruments'' (1920) was written as a memorial for Debussy.In the aftermath of the First World War, the young French composers of Les Six reacted against what they saw as the poetic, mystical quality of Debussy's music in favour of something more hard-edged.", "Their sympathiser and self-appointed spokesman Jean Cocteau wrote in 1918: \"Enough of ''nuages'', waves, aquariums, ''ondines'' and nocturnal perfumes,\" pointedly alluding to the titles of pieces by Debussy.", "Later generations of French composers had a much more positive relationship with his music.", "Messiaen was given a score of ''Pelléas et Mélisande'' as a boy and said that it was \"a revelation, love at first sight\" and \"probably the most decisive influence I have been subject to\".", "Boulez also discovered Debussy's music at a young age and said that it gave him his first sense of what modernity in music could mean.Among contemporary composers George Benjamin has described ''Prélude à l'après-midi d'un faune'' as \"the definition of perfection\"; he has conducted ''Pelléas et Mélisande'' and the critic Rupert Christiansen detects the influence of the work in Benjamin's opera ''Written on Skin'' (2012).", "Others have made orchestrations of some of the piano and vocal works, including John Adams's version of four of the Baudelaire songs (''Le Livre de Baudelaire'', 1994), Robin Holloway's of ''En blanc et noir'' (2002), and Colin Matthews's of both books of ''Préludes'' (2001–2006).The pianist Stephen Hough believes that Debussy's influence also extends to jazz and suggests that ''Reflets dans l'eau'' can be heard in the harmonies of Bill Evans." ], [ "Recordings", "In 1904, Debussy played the piano accompaniment for Mary Garden in recordings for the Compagnie française du Gramophone of four of his songs: three ''mélodies'' from the Verlaine cycle ''Ariettes oubliées'' – \"Il pleure dans mon coeur\", \"L'ombre des arbres\" and \"Green\" – and \"Mes longs cheveux\", from Act III of ''Pelléas et Mélisande''.", "He made a set of piano rolls for the Welte-Mignon company in 1913.They contain fourteen of his pieces: \"D'un cahier d'esquisses\", \"La plus que lente\", \"La soirée dans Grenade\", all six movements of ''Children's Corner'', and five of the ''Preludes'': \"Danseuses de Delphes\", \"Le vent dans la plaine\", \"La cathédrale engloutie\", \"La danse de Puck\" and \"Minstrels\".", "The 1904 and 1913 sets have been transferred to compact disc.Contemporaries of Debussy who made recordings of his music included the pianists Ricardo Viñes (in \"Poissons d'or\" from ''Images'' and \"La soirée dans Grenade\" from ''Estampes''); Alfred Cortot (numerous solo pieces as well as the Violin Sonata with Jacques Thibaud and the ''Chansons de Bilitis'' with Maggie Teyte); and Marguerite Long (\"Jardins sous la pluie\" and \"Arabesques\").", "Singers in Debussy's mélodies or excerpts from ''Pelléas et Mélisande'' included Jane Bathori, Claire Croiza, Charles Panzéra and Ninon Vallin; and among the conductors in the major orchestral works were Ernest Ansermet, Désiré-Émile Inghelbrecht, Pierre Monteux and Arturo Toscanini, and in the ''Petite Suite'', Henri Büsser, who had prepared the orchestration for Debussy.", "Many of these early recordings have been reissued on CD.In more recent times Debussy's output has been extensively recorded.", "In 2018, to mark the centenary of the composer's death, Warner Classics, with contributions from other companies, issued a 33-CD set that is claimed to include all the music Debussy wrote." ], [ "Notes, references and sources", "=== Notes ====== References ====== Sources ===* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *" ], [ "External links", "* * * * Website of Debussy museum, St. Germain-en-Laye" ] ]
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[ [ "Charles Baxter (author)" ], [ "Introduction", "'''Charles Morley Baxter''' (born May 13, 1947) is an American novelist, essayist, and poet." ], [ "Biography", "Baxter was born in Minneapolis, Minnesota, to John and Mary Barber (Eaton) Baxter.", "He graduated from Macalester College in Saint Paul in 1969.In 1974 he received his PhD in English from the University at Buffalo with a thesis on Djuna Barnes, Malcolm Lowry, and Nathanael West.Baxter taught high school in Pinconning, Michigan for a year before beginning his university teaching career at Wayne State University in Detroit, Michigan.", "He then moved to the University of Michigan, where for many years he directed the Creative Writing MFA program.", "He was a visiting professor of creative writing at the University of Iowa and at Stanford.", "He taught at the University of Minnesota and in the Warren Wilson College MFA Program for Writers.", "He retired in 2020.He was awarded a Guggenheim Fellowship in 1985.He received the PEN/Malamud Award in 2021 for Excellence in the Short Story.He married teacher Martha Ann Hauser in 1976, and has a son, Daniel.", "Baxter and Hauser eventually separated." ], [ "Works", "=== Novels ===* ''First Light'' (1987).", "An eminent astrophysicist and her brother, a small-town Buick salesman, discover how they grew so far apart and the bonds of love that still keep them together.", "* ''Shadow Play'' (1993).", "As his wife does gymnastics and magic tricks, his crazy mother invents her own vocabulary, and his aunt writes her own version of the Bible, Five Oaks Assistant City Manager Wyatt Palmer tries to live a normal life and nearly succeeds, but...* ''The Feast of Love'' (2000) (Pantheon Books), a reimagined ''Midsummer Night's Dream'', a story told through the eyes of several different people.", "Nominated for the National Book Award.", "A film version of the book, starring Morgan Freeman, Fred Ward and Greg Kinnear and directed by Robert Benton, was released in 2007.", "* ''Saul and Patsy'' (2003).", "A teacher's marriage and identity are threatened by a dangerously obsessed teenage boy at his school.", "* ''The Soul Thief'' (2008).", "A graduate student's complicated relationships lead to a disturbing case of identity theft, which ultimately leads the man to wonder if he really is who he thinks he is.", "* ''The Sun Collective'' (2020, Pantheon Books).", "The lives of two very different couples—one retired, one in their twenties—intersect in Minneapolis around an anti-capitalist collective arguing for revolution, as an underground group of extremists wage war on the homeless.=== Short story collections ===* ''Harmony of the World'' (1984).", "Winner of the Associated Writing Programs Award.", "* ''Through the Safety Net'' (1985)* ''A Relative Stranger'' (1990)* ''Believers'' (1997)* ''Gryphon: New and Selected Stories'' (2011)* ''There's Something I Want You to Do: Stories'' (February 2015)=== Non-fiction ===* ''Burning Down the House: Essays on Fiction'' (1997)* ''The Art of Subtext: Beyond Plot'' (2007).", "Winner of the 2008 Minnesota Book Award for General Non-fiction.", "* ''Wonderlands: Essays on the Life of Literature'' (2022)=== Poetry collections ===* ''Chameleon'' (1970)* ''The South Dakota Guidebook'' (1974)* ''Imaginary Paintings'' (1989)=== Edited works ===* ''The Business of Memory'' (1999)* ''Best New American Voices 2001'' (2001)* ''Bringing the Devil to His Knees: The Craft of Fiction and the Writing Life'' (2001)* ''A William Maxwell Portrait: Memories and Appreciations'' (2004)" ], [ "References", "* Greasley, Philip A.", "(2001).", "Dictionary of Midwestern Literature Volume One: The Authors.", "Indiana: Indiana University Press.", "p. 54.." ], [ "External links", "* Charles Baxter's official website* Interview with the author at Powells.com* Interview with Charles Baxter at website of Department of English at the University of Minnesota* Interview with the author at Pif Magazine.", "* Interview with Charles Baxter, author of ''The Sun Collective'' at the World Socialist Web Site" ] ]
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