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# International Mathematical Union
The **International Mathematical Union** (**IMU**) is an international organization devoted to international cooperation in the field of mathematics across the world. It is a member of the International Science Council (ISC) and supports the International Congress of Mathematicians (ICM). Its members are national mathematics organizations from more than 80 countries.
The objectives of the International Mathematical Union are: promoting international cooperation in mathematics, supporting and assisting the International Congress of Mathematicians and other international scientific meetings/conferences, acknowledging outstanding research contributions to mathematics through the awarding of scientific prizes, and encouraging and supporting other international mathematical activities, considered likely to contribute to the development of mathematical science in any of its aspects, whether pure, applied, or educational.
## History
The IMU was established in 1920, but dissolved in September 1932 and reestablished in 1950 at the Constitutive Convention in New York, de jure on September 10, 1951, when ten countries had become members. The last milestone was the General Assembly in March 1952, in Rome, Italy where the activities of the new IMU were inaugurated and the first Executive Committee, President and various commissions were elected. In 1952 the IMU was also readmitted to the ICSU. The past president of the Union is Carlos Kenig (2019--2022). The current president is Hiraku Nakajima.
At the 16th meeting of the IMU General Assembly in Bangalore, India, in August 2010, Berlin was chosen as the location of the permanent office of the IMU, which was opened on January 1, 2011, and is hosted by the Weierstrass Institute for Applied Analysis and Stochastics (WIAS), an institute of the Gottfried Wilhelm Leibniz Scientific Community, with about 120 scientists engaging in mathematical research applied to complex problems in industry and commerce.
## Commissions and committees {#commissions_and_committees}
IMU has a close relationship to mathematics education through its International Commission on Mathematical Instruction (ICMI). This commission is organized similarly to IMU with its own Executive Committee and General Assembly.
Developing countries are a high priority for the IMU and a significant percentage of its budget, including grants received from individuals, mathematical societies, foundations, and funding agencies, is spent on activities for developing countries. Since 2011 this has been coordinated by the Commission for Developing Countries (CDC).
The Committee for Women in Mathematics (CWM) is concerned with issues related to women in mathematics worldwide. It organizes the World Meeting for Women in Mathematics $((\mathrm{WM})^2)$ as a satellite event of ICM.
The International Commission on the History of Mathematics (ICHM) is operated jointly by the IMU and the Division of the History of Science (DHS) of the International Union of History and Philosophy of Science (IUHPS).
The Committee on Electronic Information and Communication (CEIC) advises IMU on matters concerning mathematical information, communication, and publishing.
## Prizes
The scientific prizes awarded by the IMU, in the quadrennial International Congress of Mathematicians (ICM), are deemed to be some of the highest distinctions in the mathematical world. These are:
- the Fields Medals (two to four awarded per Congress, since 1936);
- the IMU Abacus Medal (previously known as the Rolf Nevanlinna Prize; awarded since 1986);
- the Carl Friedrich Gauss Prize (since 2006);
- the Chern Medal (since 2010); and
- the Leelavati Award (since 2010).
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# International Mathematical Union
## Membership and General Assembly {#membership_and_general_assembly}
The IMU\'s members are Member Countries and each Member country is represented through an Adhering Organization, which may be its principal academy, a mathematical society, its research council or some other institution or association of institutions, or an appropriate agency of its government. A country starting to develop its mathematical culture and interested in building links with mathematicians all over the world is invited to join IMU as an Associate Member. For the purpose of facilitating jointly sponsored activities and jointly pursuing the objectives of the IMU, multinational mathematical societies and professional societies can join IMU as an Affiliate Member. Every four years, the IMU membership gathers in a General Assembly (GA), which consists of delegates appointed by the Adhering Organizations, together with the members of the executive committee. All important decisions are made at the GA, including the election of the officers, establishment of commissions, the approval of the budget, and any changes to the statutes and by-laws.
### Members and Associate Members {#members_and_associate_members}
The IMU has 83 (full) Member countries and two Associate Members (Bangladesh and Paraguay, marked below by light grey background).
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Country | Adhering Society | National mathematics societies |
+=======================================+===================================================================================+==========================================================================+
| Algeria | Société Mathématique d'Algérie | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Argentina | Unión Matemática Argentina | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Armenia | Institute of Mathematics, National Academy of Sciences of RA | Armenian Mathematical Union |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Australia | Australian Academy of Science | - Australian Mathematical Society |
| | | - Australian Association of Mathematics Teachers |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Austria | Austrian Academy of Sciences | Austrian Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Bangladesh | Bangladesh Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Belarus | Institute of Mathematics, National Academy of Sciences of Belarus | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Belgium | The Royal Academies for Science and the Arts of Belgium | Belgian Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Bosnia and Herzegovina | Bosnian Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Brazil | Sociedade Brasileira de Matemática | - Associação Brasileira de Estatística |
| | | - Associação Nacional dos Professores de Matemática na Educação Básica |
| | | - Sociedade Brasileira de Educação Matemática |
| | | - Sociedade Brasileira de História da Matemática |
| | | - Sociedade Brasileira de Matemática Aplicada e Computacional |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Bulgaria | Bulgarian Academy of Sciences | Union of Bulgarian Mathematicians |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Cameroon | Cameroon Mathematical Union | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Canada | National Research Council of Canada | - Canadian Mathematical Society |
| | | - Canadian Society for the History and Philosophy of Mathematics |
| | | - Statistical Society of Canada |
| | | - Canadian Applied and Industrial Mathematics Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Chile | Sociedad de Matemática de Chile | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| China`{{Cref2|Note CHN}}`{=mediawiki} | - Chinese Mathematical Society | |
| | - Mathematical Society of the Republic of China | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Colombia | Sociedad Colombiana de Matemáticas | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Croatia | Croatian Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Cuba | Universidad de la Habana | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Cyprus | Department of Mathematics and Statistics, University of Cyprus | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Czech Republic | Union of Czech Mathematicians and Physicists | Czech Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Denmark | Det Kongelige Danske Videnskabernes Selskab | Danish Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Ecuador | Sociedad Ecuatoriana de Matemática | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Egypt | Academy of Scientific Research and Technology | Egyptian Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Estonia | Estonian Academy of Sciences | Estonian Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Finland | Council of Finnish Academies | Finnish Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| France | Comité National Français des Mathématiciens | - Société Française de Statistique |
| | | - Société de Mathématiques Appliquées et Industrielles |
| | | - Société Mathématique de France |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Georgia | Georgian Mathematical Union | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Germany | Deutsche Mathematiker-Vereinigung | - Gesellschaft für Angewandte Mathematik und Mechanik |
| | | - Gesellschaft für Didaktik der Mathematik |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Greece | Academy of Athens | Greek Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Hong Kong | The Hong Kong Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Hungary | János Bolyai Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Iceland | Icelandic Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| India | Indian National Science Academy | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Indonesia | The Indonesian Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Iran | Iranian Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Ireland | Irish Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Israel | Israel Academy of Sciences and Humanities | Israel Mathematical Union |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Italy | Istituto Nazionale di Alta Matematica Francesco Severi | Unione Matematica Italiana |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Ivory Coast | Société Mathématique de Côte d\'Ivoire | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Japan | Science Council of Japan | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Kazakhstan | Institute of Mathematics and Mathematical Modeling | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Kenya | Mathematics Association of Kenya | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| South Korea | Korean Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Kyrgyzstan | Mathematical Society of Kyrgyzstan | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Latvia | Latvian Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Lithuania | Lithuanian Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Luxembourg | Luxembourg Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Malaysia | The Malaysian Academy of Mathematical Scientists | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Mexico | Mexican Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Mongolia | The Mongolian Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Montenegro | Society of Mathematicians and Physicists of Montenegro | Montenegro Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Morocco | Le Centre de Recherches Mathématiques de Rabat | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Netherlands | Het Koninklijk Wiskundig Genootschap | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| New Zealand | Royal Society Te Apārangi | New Zealand Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Nigeria | Nigerian Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Norway | The Norwegian Academy of Science and Letters | Norwegian Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Oman | Sultan Qaboos University | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Pakistan | National Mathematical Society of Pakistan | - All Pakistan Mathematical Association |
| | | - Pakistan Mathematical Society |
| | | - Punjab Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Paraguay | Sociedad Matemática Paraguaya | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Peru | Sociedad Matematica Peruana | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Philippines | Mathematical Society of the Philippines | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Poland | Polish Academy of Sciences | Polish Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Portugal | Fundação para a Ciência e Tecnologia | - Sociedade Portuguesa de Matemática |
| | | - Sociedade Portuguesa de Estatística |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Romania | Romanian Academy | Romanian Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Russia | Russian Academy of Sciences | - Moscow Mathematical Society |
| | | - St. Petersburg Mathematical Society |
| | | - Siberian Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Saudi Arabia | King Abdulaziz City for Science and Technology | Saudi Association for Mathematical Sciences |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Senegal | Senegalese Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Serbia | Mathematical Society of Serbia | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Singapore | Singapore Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Slovakia | Union of Slovak Mathematicians and Physicists | Slovak Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Slovenia | Society of Mathematicians, Physicists and Astronomers of Slovenia | Slovenian Discrete and Applied Mathematics Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| South Africa | National Research Foundation | - South African Mathematical Society |
| | | - Association for Mathematics Education of South Africa |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Spain | Comité Español de Matemáticas | - Royal Spanish Mathematical Society |
| | | - Catalan Mathematical Society |
| | | - Spanish Statistics and Operations Research Society |
| | | - Spanish Society of Applied Mathematics |
| | | - Spanish Society of Research on Mathematics Education |
| | | - Spanish Federation of Mathematics Teachers Associations |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Sweden | The Royal Swedish Academy of Sciences | Swedish Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Switzerland | Swiss Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Thailand | The Center for Promotion of Mathematical Research of Thailand | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Tunisia | Société Mathématique de Tunisie | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Turkey | Turkish Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Ukraine | Ukrainian Mathematical Society | - Kyiv Mathematical Society |
| | | - Kharkiv Mathematical Society |
| | | - Donetsk Mathematical Society |
| | | - Lviv Mathematical Society |
| | | - Ivano-Frankivsk Mathematical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| United Kingdom | London Mathematical Society | - Edinburgh Mathematical Society |
| | | - Institute of Mathematics and its Applications |
| | | - Royal Statistical Society |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| United States | U.S. National Academy of Sciences Board on International Scientific Organizations | - American Mathematical Association of Two-Year Colleges |
| | | - American Mathematical Society |
| | | - Association of Mathematics Teacher Educators |
| | | - American Statistical Association |
| | | - Association for Symbolic Logic |
| | | - Association for Women in Mathematics |
| | | - Association of State Supervisors of Mathematics |
| | | - Benjamin Banneker Association |
| | | - Institute of Mathematical Statistics |
| | | - Mathematical Association of America |
| | | - National Council of Supervisors of Mathematics |
| | | - National Council of Teachers of Mathematics |
| | | - Society for Industrial and Applied Mathematics |
| | | - Society of Actuaries |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Uruguay | Área Matemática - Programa de Desarrollo de las Ciencias Básicas | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Uzbekistan | Uzbek Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Venezuela | Asociación Matemática Venezolana | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| Vietnam | Vietnam Mathematical Society | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
| | | |
+---------------------------------------+-----------------------------------------------------------------------------------+--------------------------------------------------------------------------+
### Affiliate members {#affiliate_members}
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# International Mathematical Union
## Membership and General Assembly {#membership_and_general_assembly}
### Affiliate members {#affiliate_members}
The IMU has five affiliate members:
- African Mathematical Union (AMU)
- European Mathematical Society (EMS)
- Mathematical Council of the Americas (MCofA)
- Southeast Asian Mathematical Society (SEAMS)
- Unión Matemática de América Latina y el Caribe (UMALCA)
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# International Mathematical Union
## Organization and Executive Committee {#organization_and_executive_committee}
The International Mathematical Union is administered by an executive committee (EC) which conducts the business of the Union. The EC consists of the President, two vice-presidents, the Secretary, six Members-at-Large, all elected for a term of four years, and the Past President. The EC is responsible for all policy matters and for tasks, such as choosing the members of the ICM Program Committee and various prize committees.
## Publications
Every two months IMU publishes an electronic newsletter, *IMU-Net*, that aims to improve communication between IMU and the worldwide mathematical community by reporting on decisions and recommendations of the Union, major international mathematical events and developments, and on other topics of general mathematical interest. IMU Bulletins are published annually with the aim to inform IMU\'s members about the Union\'s current activities. In 2009 IMU published the document *Best Current Practices for Journals*.
## IMU's Involvement in developing countries {#imus_involvement_in_developing_countries}
The IMU took its first organized steps towards the promotion of mathematics in developing countries in the early 1970s and has, since then supported various activities. In 2010 IMU formed the Commission for Developing Countries (CDC) which brings together all of the past and current initiatives in support of mathematics and mathematicians in the developing world.
Some IMU Supported Initiatives:
- *Grants Program for Mathematicians:* The Commission for Developing Countries supports research travel of mathematicians based in developing countries as well as mathematics research conferences in the developing world through its Grants Program which is open to mathematicians throughout the developing world, including countries that are not (yet) members of the IMU.
- *African Mathematics Millennium Science Initiative* (AMMSI) is a network of mathematics centers in sub-Saharan Africa that organizes conferences and workshops, visiting lectureships and an extensive scholarship program for mathematics graduate students doing PhD work on the African continent.
- *Mentoring African Research in Mathematics (MARM):* IMU supported the London Mathematical Society (LMS) in founding the MARM programme, which supports mathematics and its teaching in the countries of sub-Saharan Africa via a mentoring partnership between mathematicians in the United Kingdom and African colleagues, together with their students. It focuses on cultivating long-term mentoring relations between individual mathematicians and students.
- *Volunteer Lecturer Program* (VLP) of IMU identifies mathematicians interested in contributing to the formation of young mathematicians in the developing world. The Volunteer Lecturer Program maintains a database of mathematic volunteers willing to offer month-long intensive courses at the advanced undergraduate or graduate level in degree programmes at universities in the developing world. IMU also seeks applications from universities and mathematics degree programmes in the developing world that are in need of volunteer lecturers, and that can provide the necessary conditions for productive collaboration in the teaching of advanced mathematics.
IMU also supports the *International Commission on Mathematical Instruction* (ICMI) with its programmes, exhibits and workshops in emerging countries, especially in Asia and Africa.
IMU released a report in 2008, *Mathematics in Africa: Challenges and Opportunities*, on the current state of mathematics in Africa and on opportunities for new initiatives to support mathematical development. In 2014, the IMU\'s Commission for Developing Countries CDC released an update of the report.
Additionally, reports about *Mathematics in Latin America and the Caribbean and South East Asia*. were published.
In July 2014 IMU released the report: The International Mathematical Union in the Developing World: Past, Present and Future (July 2014).
## MENAO Symposium at the ICM {#menao_symposium_at_the_icm}
In 2014, the IMU held a day-long symposium prior to the opening of the International Congress of Mathematicians (ICM), entitled *Mathematics in Emerging Nations: Achievements and Opportunities* (MENAO). Approximately 260 participants from around the world, including representatives of embassies, scientific institutions, private business and foundations attended this session. Attendees heard inspiring stories of individual mathematicians and specific developing nations.
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# International Mathematical Union
## Presidents
List of presidents of the International Mathematical Union from 1952 to the present:
1952--1954: `{{flagicon|USA}}`{=mediawiki} Marshall Harvey Stone (vice: `{{flagicon|France}}`{=mediawiki} Émile Borel, `{{flagicon|Germany}}`{=mediawiki} Erich Kamke)
1955--1958: `{{flagicon|Germany}}`{=mediawiki} Heinz Hopf (vice: `{{flagicon|France}}`{=mediawiki} Arnaud Denjoy, `{{flagicon|GBR}}`{=mediawiki} W. V. D. Hodge)
1959--1962: `{{flagicon|Finland}}`{=mediawiki} Rolf Nevanlinna (vice: `{{flagicon|Soviet Union}}`{=mediawiki} Pavel Alexandrov, `{{flagicon|USA}}`{=mediawiki} Marston Morse)
1963--1966: `{{flagicon|Switzerland}}`{=mediawiki} Georges de Rham (vice: `{{flagicon|France}}`{=mediawiki} Henri Cartan, `{{flagicon|Poland}}`{=mediawiki} Kazimierz Kuratowski)
1967--1970: `{{flagicon|France}}`{=mediawiki} Henri Cartan (vice: `{{flagicon|Soviet Union}}`{=mediawiki} Mikhail Lavrentyev, `{{flagicon|USA}}`{=mediawiki} Deane Montgomery)
1971--1974: `{{flagicon|India}}`{=mediawiki} K. S. Chandrasekharan (vice: `{{flagicon|USA}}`{=mediawiki} Abraham Adrian Albert, `{{flagicon|Soviet Union}}`{=mediawiki} Lev Pontryagin)
1975--1978: `{{flagicon|USA}}`{=mediawiki} Deane Montgomery (vice: `{{flagicon|GBR}}`{=mediawiki} J. W. S. Cassels, `{{flagicon|Romania}}`{=mediawiki} Miron Nicolescu, `{{flagicon|Romania}}`{=mediawiki} Gheorghe Vrânceanu)
1979--1982: `{{flagicon|Sweden}}`{=mediawiki} Lennart Carleson (vice: `{{flagicon|Japan}}`{=mediawiki} Masayoshi Nagata, `{{flagicon|Soviet Union}}`{=mediawiki} Yuri Vasilyevich Prokhorov)
1983--1986: `{{flagicon|Germany}}`{=mediawiki} Jürgen Moser (vice: `{{flagicon|Soviet Union}}`{=mediawiki} Ludvig Faddeev, `{{flagicon|France}}`{=mediawiki} Jean-Pierre Serre)
1987--1990: `{{flagicon|Soviet Union}}`{=mediawiki} Ludvig Faddeev (vice: `{{flagicon|Austria}}`{=mediawiki} Walter Feit, `{{flagicon|Sweden}}`{=mediawiki} Lars Hörmander)
1991--1994: `{{flagicon|France}}`{=mediawiki} Jacques-Louis Lions (vice: `{{flagicon|GBR}}`{=mediawiki} John H. Coates, `{{flagicon|USA}}`{=mediawiki} David Mumford)
1995--1998: `{{flagicon|USA}}`{=mediawiki} David Mumford (vice: `{{flagicon|Russia}}`{=mediawiki} Vladimir Arnold, `{{flagicon|Germany}}`{=mediawiki} Albrecht Dold)
1999--2002: `{{flagicon|Brazil}}`{=mediawiki} Jacob Palis (vice: `{{flagicon|GBR}}`{=mediawiki} Simon Donaldson, `{{flagicon|Japan}}`{=mediawiki} Shigefumi Mori)
2003--2006: `{{flagicon|GBR}}`{=mediawiki} John M
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# International Council for Science
The **International Council for Science** (**ICSU**, after its former name, **International Council of Scientific Unions**) was an international non-governmental organization devoted to international cooperation in the advancement of science. Its members were national scientific bodies and international scientific unions.
In 2017, the ICSU comprised 122 multi-disciplinary National Scientific Members, Associates and Observers representing 142 countries and 31 international, disciplinary Scientific Unions. ICSU also had 22 Scientific Associates. In July 2018, ICSU merged with the International Social Science Council (ISSC) to form the International Science Council (ISC) at a constituent general assembly in Paris.
## Mission and principles {#mission_and_principles}
The ICSU\'s mission was to strengthen international science for the benefit of society. To do this, the ICSU mobilized the knowledge and resources of the international scientific community to:
- Identify and address major issues of importance to science and society.
- Facilitate interaction amongst scientists across all disciplines and from all countries.
- Promote the participation of all scientists -- regardless of race, citizenship, language, political stance, or gender -- in the international scientific endeavour.
- Provide independent, authoritative advice to stimulate constructive dialogue between the scientific community and governments, civil society, and the private sector.\"
Activities focused on three areas: International Research Collaboration, Science for Policy, and Universality of Science.
## History
In July 2018, the ICSU became the International Science Council (ISC).
The ICSU itself was one of the oldest non-governmental organizations in the world, representing the evolution and expansion of two earlier bodies known as the International Association of Academies (IAA; 1899--1914) and the International Research Council (IRC; 1919--1931). In 1998, Members agreed that the Council\'s current composition and activities would be better reflected by modifying the name from the International Council of Scientific Unions to the International Council for Science, while its rich history and strong identity would be well served by retaining the existing acronym, ICSU.
## Universality of science {#universality_of_science}
> The **Principle of Freedom and Responsibility in Science**: the free and responsible practice of science is fundamental to scientific advancement and human and environmental well-being. Such practice, in all its aspects, requires freedom of movement, association, expression and communication for scientists, as well as equitable access to data, information, and other resources for research. It requires responsibility at all levels to carry out and communicate scientific work with integrity, respect, fairness, trustworthiness, and transparency, recognizing its benefits and possible harms. In advocating the free and responsible practice of science, the council promotes equitable opportunities for access to science and its benefits, and opposes discrimination based on such factors as ethnic origin, religion, citizenship, language, political or other opinion, sex, gender identity, sexual orientation, disability, or age.
The International Science Council\'s Committee on Freedom and Responsibility in Science (CFRS) \"oversees this commitment and is the guardian of this work.\"
## Structure
The ICSU Secretariat (20 staff in 2012) in Paris ensured the day-to-day planning and operations under the guidance of an elected executive board. Three Policy Committees − Committee on Scientific Planning and Review (CSPR), Committee on Freedom and Responsibility in the conduct of Science (CFRS) and Committee on Finance − assisted the executive board in its work and a General Assembly of all Members was convened every three years. ICSU has three Regional Offices − Africa, Asia and the Pacific as well as Latin America and the Caribbean.
## Finances
The principal source of ICSU\'s finances was the contributions it receives from its members. Other sources of income are the framework contracts from UNESCO (United Nations Educational, Scientific and Cultural Organization) and grants and contracts from United Nations bodies, foundations and agencies, which are used to support the scientific activities of the ICSU Unions and interdisciplinary bodies.
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# International Council for Science
## Member organizations {#member_organizations}
Abbreviation Union Member Since Field
-------------- ----------------------------------------------------------------------- -------------- ----------------------------------------------
IAU International Astronomical Union 1922 Astronomy
IBRO International Brain Research Organization 1993 Neuroscience
ICA International Cartographic Association 1990 Cartography
IGU International Geographical Union 1923 Geography
IMU International Mathematical Union 1922 Mathematics
INQUA International Union for Quaternary Research 2005 Quaternary Period
ISA International Sociological Association 2011 Sociology and Social Sciences
ISPRS International Society for Photogrammetry and Remote Sensing 2002 Photogrammetry and Remote Sensing
IUAES International Union of Anthropological and Ethnological Sciences 1993 Anthropology and Ethnology
IUBMB International Union of Biochemistry and Molecular Biology 1955 Biochemistry and Molecular Biology
IUBS International Union of Biological Sciences 1925 Biology
IUCr International Union of Crystallography 1947 Crystallography
IUFRO International Union of Forest Research Organizations 2005 Forestry
IUFoST International Union of Food Science and Technology 1996 Food science and Food technology
IUGG International Union of Geodesy and Geophysics 1919 Geodesy and Geophysics
IUGS International Union of Geological Sciences 1922 Geology
IUHPS International Union of History and Philosophy of Science 1922 History of science and Philosophy of science
IUIS International Union of Immunological Societies 1976 Immunology
IUMRS International Union of Materials Research Societies 2005 Materials science
IUMS International Union of Microbiological Societies 1982 Microbiology
IUNS International Union of Nutritional Sciences 1968 Nutrition
IUPAB International Union for Pure and Applied Biophysics 1966 Biophysics
IUPAC International Union of Pure and Applied Chemistry 1922 Chemistry
IUPAP International Union of Pure and Applied Physics 1922 Physics
IUPESM International Union for Physical and Engineering Sciences in Medicine 1999 Medical physics
IUPHAR International Union of Basic and Clinical Pharmacology 1972 Pharmacology
IUPS International Union of Physiological Sciences 1955 Physiology
IUPsyS International Union of Psychological Science 1982 Psychology
IUSS International Union of Soil Sciences 1993 Soil science
IUTAM International Union of Theoretical and Applied Mechanics 1947 Mechanics
IUTOX International Union of Toxicology 1996 Toxicology
URSI International Union of Radio Science 1922 Radio science
### Associate member organizations {#associate_member_organizations}
Abbr
| 323 |
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| 1 |
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# IBM mainframe
**IBM mainframes** are large computer systems produced by IBM since 1952. During the 1960s and 1970s, IBM dominated the computer market with the 7000 series and the later System/360, followed by the System/370. Current mainframe computers in IBM\'s line of business computers are developments of the basic design of the System/360.
## First and second generation {#first_and_second_generation}
From 1952 into the late 1960s, IBM manufactured and marketed several large computer models, known as the IBM 700/7000 series. The first-generation 700s were based on vacuum tubes, while the later, second-generation 7000s used transistors. These machines established IBM\'s dominance in electronic data processing (\"EDP\"). IBM had two model categories: one (701, 704, 709, 7030, 7090, 7094, 7040, 7044) for engineering and scientific use, and one (702, 705, 705-II, 705-III, 7080, 7070, 7072, 7074, 7010) for commercial or data processing use. The two categories, scientific and commercial, generally used common peripherals but had completely different instruction sets, and there were incompatibilities even within each category.
IBM initially sold its computers without any software, expecting customers to write their own; programs were manually initiated, one at a time. Later, IBM provided compilers for the newly developed higher-level programming languages Fortran, COMTRAN and later COBOL. The first operating systems for IBM computers were written by IBM customers who did not wish to have their very expensive machines (US\$2M in the mid-1950s) sitting idle while operators set up jobs manually. These first operating systems were essentially scheduled work queues. It is generally thought the first operating system used for real work was GM-NAA I/O, produced by General Motors\' Research division in 1956. IBM enhanced one of GM-NAA I/O\'s successors, the SHARE Operating System, and provided it to customers under the name IBSYS. As software became more complex and important, the cost of supporting it on so many different designs became burdensome, and this was one of the factors which led IBM to develop System/360 and its operating systems.
The second generation (transistor-based) products were a mainstay of IBM\'s business and IBM continued to make them for several years after the introduction of the System/360. (Some IBM 7094s remained in service into the 1980s.)
## Smaller machines {#smaller_machines}
Prior to System/360, IBM also sold computers smaller in scale that were not considered mainframes, though they were still bulky and expensive by modern standards. These included:
- IBM 650 (vacuum tube logic, decimal architecture, drum memory, business and scientific)
- IBM 305 RAMAC (vacuum tube logic, first computer with disk storage; *see:* Early IBM disk storage)
- IBM 1400 series (business data processing; very successful and many 1400 peripherals were used with the 360s)
- IBM 1620 (decimal architecture, engineering, scientific, and education)
IBM had difficulty getting customers to upgrade from the smaller machines to the mainframes because so much software had to be rewritten. The 7010 was introduced in 1962 as a mainframe-sized 1410. The later Systems 360 and 370 could emulate the 1400 machines. A desk-size machine with a different instruction set, the IBM 1130, was released concurrently with the System/360 to address the niche occupied by the 1620. It used the same EBCDIC character encoding as the 360 and was mostly programmed in Fortran, which was relatively easy to adapt to larger machines when necessary.
IBM also introduced smaller machines after S/360. These included:
- IBM System/7 (semiconductor memory, process control, incompatible replacement for IBM 1800
- IBM Series/1
- IBM 3790
- IBM 8100
- IBM System/3 (Introduced 96 column card)
*Midrange computer* is a designation used by IBM for a class of computer systems which fall in between mainframes and microcomputers.
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# IBM mainframe
## IBM System/360 {#ibm_system360}
IBM announced the System/360 (S/360) line of mainframes in April 1964. The System/360 was a single series of compatible models for both commercial and scientific use. The number \"360\" suggested a \"360 degree,\" or \"all-around\" computer system. System/360 incorporated features which had previously been present on only either the commercial line (such as decimal arithmetic and byte addressing) or the engineering and scientific line (such as floating-point arithmetic). Some of the arithmetic units and addressing features were optional on some models of the System/360. However, models were upward compatible and most were also downward compatible. The System/360 was also the first computer in wide use to include dedicated hardware provisions for the use of operating systems. Among these were supervisor and application mode programs and instructions, as well as built-in memory protection facilities. Hardware memory protection was provided to protect the operating system from the user programs (tasks) and user tasks from each other. The new machine also had a larger address space than the older mainframes, 24 bits addressing 8-bit bytes vs. a typical 18 bits addressing 36-bit words.
The smaller models in the System/360 line (e.g. the 360/30) were intended to replace the 1400 series while providing an easier upgrade path to the larger 360s. To smooth the transition from the second generation to the new line, IBM used the 360\'s microprogramming capability to emulate the more popular older models. Thus 360/30s with this added cost feature could run 1401 programs and the larger 360/65s could run 7094 programs. To run old programs, the 360 had to be halted and restarted in emulation mode. Many customers kept using their old software and one of the features of the later System/370 was the ability to switch to emulation mode and back under operating system control.
Operating systems for the System/360 family included OS/360 (with PCP, MFT, and MVT), BOS/360, TOS/360, and DOS/360.
The System/360 later evolved into the System/370, the System/390, and the 64-bit zSeries, System z, and zEnterprise machines. System/370 introduced virtual memory capabilities in all models other than the first System/370 models; the OS/VS1 variant of OS/360 MFT, the OS/VS2 (SVS) variant of OS/360 MVT, and the DOS/VS variant of DOS/360 were introduced to use the virtual memory capabilities, followed by MVS, which, unlike the earlier virtual-memory operating systems, ran separate programs in separate address spaces, rather than running all programs in a single virtual address space. The virtual memory capabilities also allowed the system to support virtual machines; the VM/370 hypervisor would run one or more virtual machines running either standard System/360 or System/370 operating systems or the single-user Conversational Monitor System (CMS). A time-sharing VM system could run multiple virtual machines, one per user, with each virtual machine running an instance of CMS.
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# IBM mainframe
## Today\'s systems {#todays_systems}
The IBM Z family, introduced in 2000 with the z900, supports z/Architecture, which extends the architecture used by the System/390 mainframes to 64 bits.
### Processor units {#processor_units}
The different processors on current IBM mainframes are:
- CP, central processor: general-purpose processor
- IFL, Integrated Facility for Linux: dedicated to Linux OSes (optionally under z/VM)
- ICF, Integrated Coupling Facility: designed to support Parallel Sysplex operations
- SAP, System Assist Processor: designed to handle various system accounting, management, and I/O channel operations
- zAAP, System z Application Assist Processor: currently limited to run only Java and XML processing
- zIIP, System z Integrated Information Processor: dedicated to run specific workloads including IBM Db2, XML, and IPSec
These are essentially identical, but distinguished for software cost control: all but CP are slightly restricted such they cannot be used to run arbitrary operating systems, and thus do not count in software licensing costs (which are typically based on the number of CPs). There are other supporting processors typically installed inside mainframes such as cryptographic accelerators (CryptoExpress), the OSA-Express networking processor, and FICON Express disk I/O processors.
Software to allow users to run \"traditional\" workloads on zIIPs and zAAPs was briefly marketed by Neon Enterprise Software as \"zPrime\" but was withdrawn from the market in 2011 after a lawsuit by IBM.
### Operating systems {#operating_systems}
The primary operating systems in use on current IBM mainframes include z/OS (which followed MVS/ESA and OS/390 in the OS/360 lineage), z/VM (which followed VM/ESA and VM/XA SP in the CP-40 lineage), z/VSE (which is in the DOS/360 lineage), z/TPF (a successor of Transaction Processing Facility in the Airlines Control Program lineage), and Linux on IBM Z (e.g., Debian, Red Hat Enterprise Linux, SUSE Linux Enterprise Server). Some systems run MUSIC/SP, as well as UTS (Mainframe UNIX). In October 2008, Sine Nomine Associates introduced OpenSolaris on System z; it has since been discontinued.
### Middleware
Current IBM mainframes run all the major enterprise transaction processing environments and databases, including CICS, IMS, WebSphere Application Server, IBM Db2, and Oracle. In many cases these software subsystems can run on more than one mainframe operating system.
### Emulators
There are software-based emulators for the System/370, System/390, and System z hardware, including FLEX-ES, which runs under UnixWare or Linux, and the freely available Hercules, which runs under Linux, FreeBSD, Solaris, macOS and Microsoft Windows. IBM offers an emulator called zPDT (System z Personal Development Tool) which runs on Linux on x86-64 machines
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# International Astronomical Union
The **International Astronomical Union** (**IAU**; *Union astronomique internationale*, **UAI**) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded on 28 July 1919 in Brussels, Belgium and is based in Paris, France.
The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. `{{As of|May 2024|post=,}}`{=mediawiki} the Union had 85 national members and 12,734 individual members, spanning 90 countries and territories.
Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy and includes various scientific meetings. The Union is best known for being the leading authority in assigning official names and designations to astronomical objects, and for setting uniform definitions for astronomical principles. It also coordinates with national and international partners, such as UNESCO, to fulfill its mission.
The IAU is a member of the International Science Council, which is composed of international scholarly and scientific institutions and national academies of sciences.
## Function
The International Astronomical Union is an international association of professional astronomers, at the PhD level and beyond, active in professional research and education in astronomy. Among other activities, it acts as the recognized authority for assigning designations and names to celestial bodies (stars, planets, asteroids, etc.) and any surface features on them.
The IAU is a member of the International Science Council. Its main objective is to promote and safeguard the science of astronomy in all its aspects through international cooperation. The IAU maintains friendly relations with organizations that include amateur astronomers in their membership. The IAU has its head office on the second floor of the *Institut d\'Astrophysique de Paris* in the 14th arrondissement of Paris.
This organisation has many working groups. For example, the Working Group for Planetary System Nomenclature (WGPSN), which maintains the astronomical naming conventions and planetary nomenclature for planetary bodies, and the Working Group on Star Names (WGSN), which catalogues and standardizes proper names for stars. The IAU is also responsible for the system of astronomical telegrams which are produced and distributed on its behalf by the Central Bureau for Astronomical Telegrams. The Minor Planet Center also operates under the IAU, and is a \"clearinghouse\" for all non-planetary or non-moon bodies in the Solar System.
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# International Astronomical Union
## History
The IAU was founded on 28 July 1919, at the Constitutive Assembly of the International Research Council (now the International Science Council) held in Brussels, Belgium. Two subsidiaries of the IAU were also created at this assembly: the *International Time Commission* seated at the International Time Bureau in Paris, France, and the *International Central Bureau of Astronomical Telegrams* initially seated in Copenhagen, Denmark.
The seven initial member states were Belgium, Canada, France, Great Britain, Greece, Japan, and the United States, soon to be followed by Italy and Mexico. The first executive committee consisted of Benjamin Baillaud (President, France), Alfred Fowler (General Secretary, UK), and four vice presidents: William Campbell (US), Frank Dyson (UK), Georges Lecointe (Belgium), and Annibale Riccò (Italy). Thirty-two Commissions (referred to initially as Standing Committees) were appointed at the Brussels meeting and focused on topics ranging from relativity to minor planets. The reports of these 32 Commissions formed the main substance of the first General Assembly, which took place in Rome, Italy, 2--10 May 1922.
By the end of the first General Assembly, ten additional nations (Australia, Brazil, Czechoslovakia, Denmark, the Netherlands, Norway, Poland, Romania, South Africa, and Spain) had joined the Union, bringing the total membership to 19 countries. Although the Union was officially formed eight months after the end of World War I, international collaboration in astronomy had been strong in the pre-war era (e.g., the *Astronomische Gesellschaft Katalog* projects since 1868, the Astrographic Catalogue since 1887, and the International Union for Solar research since 1904).
The first 50 years of the Union\'s history are well documented. Subsequent history is recorded in the form of reminiscences of past IAU Presidents and General Secretaries. Twelve of the fourteen past General Secretaries in the period 1964--2006 contributed their recollections of the Union\'s history in IAU Information Bulletin No. 100. Six past IAU Presidents in the period 1976--2003 also contributed their recollections in IAU Information Bulletin No. 104.
In 2015 and 2019, the Union held the NameExoWorlds contests.
Starting in 2024, the Union, in partnership with the United Nations, is poised to play a critical role in developing the legislation and framework for lunar industrialization.
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# International Astronomical Union
## Composition
As of 1 August 2019, the IAU has a total of 13,701 *individual members*, who are professional astronomers from 102 countries worldwide; 81.7% of individual members are male, while 18.3% are female.
Membership also includes 82 *national members*, professional astronomical communities representing their country\'s affiliation with the IAU. National members include the Australian Academy of Science, the Chinese Astronomical Society, the French Academy of Sciences, the Indian National Science Academy, the National Academies (United States), the National Research Foundation of South Africa, the National Scientific and Technical Research Council (Argentina), the Council of German Observatories, the Royal Astronomical Society (United Kingdom), the Royal Astronomical Society of New Zealand, the Royal Swedish Academy of Sciences, the Russian Academy of Sciences, and the Science Council of Japan, among many others.
The sovereign body of the IAU is its *General Assembly*, which comprises all members. The Assembly determines IAU policy, approves the Statutes and By-Laws of the Union (and amendments proposed thereto) and elects various committees.
The right to vote on matters brought before the Assembly varies according to the type of business under discussion. The Statutes consider such business to be divided into two categories:
- **issues of a \"primarily scientific nature\"** (as determined by the Executive Committee), upon which voting is restricted to individual members, and
- **all other matters** (such as Statute revision and procedural questions), upon which voting is restricted to the representatives of national members.
On budget matters (which fall into the second category), votes are weighted according to the relative subscription levels of the national members. A second category vote requires a turnout of at least two-thirds of national members to be valid. An absolute majority is sufficient for approval in any vote, except for Statute revision which requires a two-thirds majority. An equality of votes is resolved by the vote of the President of the Union.
### List of national members {#list_of_national_members}
#### Africa
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### Terminated national members {#terminated_national_members}
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# International Astronomical Union
## General Assemblies {#general_assemblies}
Since 1922, the IAU General Assembly meets every three years, except for the period between 1938 and 1948, due to World War II. After a Polish request in 1967, and by a controversial decision of the then President of the IAU, an *Extraordinary IAU General Assembly* was held in September 1973 in Warsaw, Poland, to commemorate the 500th anniversary of the birth of Nicolaus Copernicus, soon after the regular 1973 GA had been held in Sydney.
Meeting Year Venue
-------------------------------------- ------ -------------------------------------------------------------
Ist IAU General Assembly (1st) 1922 Rome, Italy
IInd IAU General Assembly (2nd) 1925 Cambridge, England, United Kingdom
IIIrd IAU General Assembly (3rd) 1928 Leiden, Netherlands
IVth IAU General Assembly (4th) 1932 Cambridge, Massachusetts, United States
Vth IAU General Assembly (5th) 1935 Paris, France
VIth IAU General Assembly (6th) 1938 Stockholm, Sweden
VIIth IAU General Assembly (7th) 1948 Zürich, Switzerland
VIIIth IAU General Assembly (8th) 1952 Rome, Italy
IXth IAU General Assembly (9th) 1955 Dublin, Ireland
Xth IAU General Assembly (10th) 1958 Moscow, Soviet Union
XIth IAU General Assembly (11th) 1961 Berkeley, California, United States
XIIth IAU General Assembly (12th) 1964 Hamburg, West Germany
XIIIth IAU General Assembly (13th) 1967 Prague, Czechoslovakia
XIVth IAU General Assembly (14th) 1970 Brighton, England, United Kingdom
XVth IAU General Assembly (15th) 1973 Sydney, Australia
XVIth IAU General Assembly (16th) 1976 Grenoble, France
XVIIth IAU General Assembly (17th) 1979 Montreal, Quebec, Canada
XVIIIth IAU General Assembly (18th) 1982 Patras, Greece
XIXth IAU General Assembly (19th) 1985 New Delhi, India
XXth IAU General Assembly (20th) 1988 Baltimore, Maryland, United States
XXIst IAU General Assembly (21st) 1991 Buenos Aires, Argentina
XXIInd IAU General Assembly (22nd) 1994 The Hague, Netherlands
XXIIIrd IAU General Assembly (23rd) 1997 Kyoto, Japan
XXIVth IAU General Assembly (24th) 2000 Manchester, England, United Kingdom
XXVth IAU General Assembly (25th) 2003 Sydney, Australia
XXVIth IAU General Assembly (26th) 2006 Prague, Czech Republic
XXVIIth IAU General Assembly (27th) 2009 Rio de Janeiro, Brazil
XXVIIIth IAU General Assembly (28th) 2012 Beijing, China
XXIXth IAU General Assembly (29th) 2015 Honolulu, Hawaii, United States
XXXth IAU General Assembly (30th) 2018 Vienna, Austria
XXXIst IAU General Assembly (31st) 2022 Busan, South Korea
XXXIInd IAU General Assembly (32nd) 2024 Cape Town, South Africa
XXXIIIrd IAU General Assembly (33rd) 2027 Rome, Italy{{cite web \|title=iau2410 --- Press Release
XXXIVth IAU General Assembly (34th) 2030 Santiago, Chile{{cite web \|title=iau2410 --- Press Release
## List of the presidents of the IAU {#list_of_the_presidents_of_the_iau}
Sources.
+-------------------------------------------------------------------------------+---+------------------------------------------------------------------------+---+-------------------------------------------------------------------------+
| - (1919--1922) `{{flagicon|FRA|1794}}`{=mediawiki} Benjamin Baillaud | | - (1958--1961) `{{flagicon|NED}}`{=mediawiki} Jan Oort | | - (1991--1994) `{{flagicon|RUS|1991}}`{=mediawiki} Alexandr Boyarchuk |
| - (1922--1925) `{{flagicon|USA|1912}}`{=mediawiki} William Wallace Campbell | | - (1961--1964) `{{flagicon|USSR}}`{=mediawiki} Victor Ambartsumian | | - (1994--1997) `{{flagicon|NED}}`{=mediawiki} Lodewijk Woltjer |
| - (1925--1928) `{{flagicon|NED}}`{=mediawiki} Willem de Sitter | | - (1964--1967) `{{flagicon|BEL}}`{=mediawiki} Pol Swings | | - (1997--2000) `{{flagicon|USA}}`{=mediawiki} Robert Kraft |
| - (1928--1932) `{{flagicon|UK}}`{=mediawiki} Frank Watson Dyson | | - (1967--1970) `{{flagicon|West Germany}}`{=mediawiki} Otto Heckmann | | - (2000--2003) `{{flagicon|ITA}}`{=mediawiki} Franco Pacini |
| - (1932--1935) `{{flagicon|USA|1912}}`{=mediawiki} Frank Schlesinger | | - (1970--1973) `{{flagicon|DEN}}`{=mediawiki} Bengt Strömgren | | - (2003--2006) `{{flagicon|AUS}}`{=mediawiki} Ronald Ekers |
| - (1935--1938) `{{flagicon|FRA|1794}}`{=mediawiki} Ernest Esclangon | | - (1973--1976) `{{flagicon|USA}}`{=mediawiki} Leo Goldberg | | - (2006--2009) `{{flagicon|ARG}}`{=mediawiki} Catherine Cesarsky |
| - (1938--1944) `{{flagicon|UK}}`{=mediawiki} Arthur Eddington | | - (1976--1979) `{{flagicon|NED}}`{=mediawiki} Adriaan Blaauw | | - (2009--2012) `{{flagicon|USA}}`{=mediawiki} Robert Williams |
| - (1944--1948) `{{flagicon|UK}}`{=mediawiki} Harold Spencer Jones | | - (1979--1982) `{{flagicon|IND}}`{=mediawiki} Vainu Bappu | | - (2012--2015) `{{flagicon|JPN}}`{=mediawiki} Norio Kaifu |
| - (1948--1952) `{{flagicon|SWE}}`{=mediawiki} Bertil Lindblad | | - (1982--1985) `{{flagicon|UK}}`{=mediawiki} Robert Hanbury Brown | | - (2015--2018) `{{flagicon|MEX}}`{=mediawiki} Silvia Torres-Peimbert |
| - (1952--1955) `{{flagicon|USA|1912}}`{=mediawiki} Otto Struve | | - (1985--1988) `{{flagicon|ARG}}`{=mediawiki} Jorge Sahade | | - (2018--2021) `{{flagicon|NED}}`{=mediawiki} Ewine van Dishoeck |
| - (1955--1958) `{{flagicon|FRA|1794}}`{=mediawiki} André-Louis Danjon | | - (1988--1991) `{{flagicon|JPN}}`{=mediawiki} Yoshihide Kozai | | - (2021--2024) `{{flagicon|USA}}`{=mediawiki} Debra Elmegreen |
| | | | | - (2024--present) `{{flagicon|SUI}}`{=mediawiki} Willy Benz |
+-------------------------------------------------------------------------------+---+------------------------------------------------------------------------+---+-------------------------------------------------------------------------+
## Commission 46: Education in astronomy {#commission_46_education_in_astronomy}
Commission 46 is a Committee of the Executive Committee of the IAU, playing a special role in the discussion of astronomy development with governments and scientific academies. The IAU is affiliated with the International Council of Scientific Unions (ICSU), a non-governmental organization representing a global membership that includes both national scientific bodies and international scientific unions. They often encourage countries to become members of the IAU. The Commission further seeks to development, information or improvement of astronomical education. Part of Commission 46, is Teaching Astronomy for Development (TAD) program in countries where there is currently very little astronomical education. Another program is named the Galileo Teacher Training Program (GTTP), is a project of the International Year of Astronomy 2009, among which Hands-On Universe that will concentrate more resources on education activities for children and schools designed to advance sustainable global development. GTTP is also concerned with the effective use and transfer of astronomy education tools and resources into classroom science curricula. A strategic plan for the period 2010--2020 has been published.
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# International Astronomical Union
## Publications
In 2004 the IAU contracted with the Cambridge University Press to publish the *Proceedings of the International Astronomical Union*.
In 2007, the Communicating Astronomy with the Public Journal Working Group prepared a study assessing the feasibility of the *Communicating Astronomy with the Public Journal* (*CAP Journal*)
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# Incremental reading
**Incremental reading** is a software-assisted method for learning and retaining information from reading, which involves the creation of flashcards out of electronic articles. \"Incremental reading\" means \"reading in portions\". Instead of a linear reading of articles one at a time, the method works by keeping a large list of electronic articles or books (often dozens or hundreds) and reading parts of several articles in each session. The user prioritizes articles in the reading list. During reading, key points of articles are broken up into flashcards, which are then learned and reviewed over an extended period with the help of a spaced repetition algorithm.
This use of flashcards at later stages of the process is based on the spacing effect (the phenomenon whereby learning is greater when studying is spread out over time) and the testing effect (the finding that long-term memory is increased when some of the learning periods are devoted to retrieving the to-be-remembered information through testing). It targets people trying to learn for life a large amount of information, particularly if it comes from various sources.
## History
The method itself is often credited to the Polish software developer Piotr Woźniak. He implemented the first version of incremental reading in 1999 in SuperMemo 99, providing the essential tools of the method: a prioritized reading list and the possibility to extract portions of articles and to create cloze deletions. The term \"incremental reading\" itself appeared the following year with SuperMemo 10 (2000). Later SuperMemo programmes subsequently enhanced the tools and techniques involved, such as webpage imports, material overload handling, etc.
Limited incremental reading support for the text editor Emacs appeared in 2007.
An Anki add-on for incremental reading was later published in 2011; for Anki 2.0 and 2.1, another add-on is available.
Incremental reading was the first of a series of related concepts invented by Piotr Woźniak: incremental image learning, incremental video, incremental audio, incremental mail processing, incremental problem solving, and incremental writing. \"Incremental learning\" is the term Wozniak uses to refer to those concepts.
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# Incremental reading
## Method
When reading an electronic article, the user extracts the most important parts (similar to underlining or highlighting a paper article) and gradually distills them into flashcards. Flashcards are information presented in a question-answer format (making active recall possible). Cloze deletions are often used in incremental reading, as they are easy to create from the text. Both extracts and flashcards are scheduled independently from the original article.
With time and reviews, articles are supposed to be gradually converted into extracts and extracts into flashcards. Hence, incremental reading is a method of breaking down information from electronic articles into sets of flashcards.
Contrary to extracts, flashcards are reviewed with active recall. This means that extracts such as \"George Washington was the first U.S. president\" must ultimately be converted into questions like \"Who was the first U.S. president?\" (answer: George Washington), or cloze deletions like \"\[\...\] was the first U.S. president.\"
This flashcard creation process is semi-automated -- the reader chooses which material to learn and edits the precise wording of the questions. In contrast, the software assists in prioritizing articles and making the flashcards and does the scheduling: it calculates the time for the reader to review each chunk according to the rules of a spaced repetition algorithm. This means that all processed pieces of information are presented at increasing intervals.
Individual articles are read in portions proportional to the attention span, which depends on the user, their mood, the article, etc. This allows for a substantial gain in attention, according to Piotr Wozniak.
Without spaced repetition, the reader would quickly get lost in the glut of information when studying dozens of subjects in parallel. However, spaced repetition makes it possible to retain traces of the processed material in memory
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# Intensive insulin therapy
**Intensive insulin therapy** or **flexible insulin therapy** is a therapeutic regimen for diabetes mellitus treatment. This newer approach contrasts with conventional insulin therapy. Rather than minimize the number of insulin injections per day (a technique which demands a rigid schedule for food and activities), the intensive approach favors flexible meal times with variable carbohydrate as well as flexible physical activities. The trade-off is the increase from 2 or 3 injections per day to 4 or more injections per day, which was considered \"intensive\" relative to the older approach. In North America in 2004, many endocrinologists prefer the term \"flexible insulin therapy\" (FIT) to \"intensive therapy\" and use it to refer to any method of replacing insulin that attempts to mimic the pattern of small continuous basal insulin secretion of a working pancreas combined with larger insulin secretions at mealtimes. The semantic distinction reflects changing treatment.
## Rationale
Long-term studies like the UK Prospective Diabetes Study (*UKPDS*) and the Diabetes control and complications trial (*DCCT*) showed that intensive insulin therapy achieved blood glucose levels closer to non-diabetic people and that this was associated with reduced frequency and severity of blood vessel damage. Damage to large and small blood vessels (macro- and microvascular disease) is central to the development of complications of diabetes.
This evidence convinced most physicians who specialize in diabetes care that an important goal of treatment is to make the biochemical profile of the diabetic patient (blood lipids, HbA1c, etc.) as close to the values of non-diabetic people as possible. This is especially true for young patients with many decades of life ahead.
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# Intensive insulin therapy
## General description {#general_description}
A working pancreas continually secretes small amounts of insulin into the blood to maintain normal glucose levels, which would otherwise rise from glucose release by the liver, especially during the early morning dawn phenomenon. This insulin is referred to as *basal insulin secretion*, and constitutes almost half the insulin produced by the normal pancreas.
Bolus insulin is produced during the digestion of meals. Insulin levels rise immediately as we begin to eat, remaining higher than the basal rate for 1 to 4 hours. This meal-associated (*prandial*) insulin production is roughly proportional to the amount of carbohydrate in the meal.
Intensive or flexible therapy involves supplying a continual supply of insulin to serve as the *basal insulin*, supplying meal insulin in doses proportional to nutritional load of the meals, and supplying extra insulin when needed to correct high glucose levels. These three components of the insulin regimen are commonly referred to as basal insulin, bolus insulin, and high glucose correction insulin.
### Two common regimens: pens, injection ports, and pumps {#two_common_regimens_pens_injection_ports_and_pumps}
One method of intensive insulinotherapy is based on multiple daily injections (sometimes referred to in medical literature as *MDI*). Meal insulin is supplied by injection of rapid-acting insulin before each meal in an amount proportional to the meal. Basal insulin is provided as a once or twice daily injection of dose of a long-acting insulin.
In an MDI regimen, long-acting insulins are preferred for basal use. An older insulin used for this purpose is ultralente, and beef ultralente in particular was considered for decades to be the gold standard of basal insulin. Long-acting insulin analogs such as insulin glargine (brand name *Lantus*, made by Sanofi-Aventis) and insulin detemir (brand name *Levemir*, made by Novo Nordisk) are also used, with insulin glargine used more than insulin detemir. Rapid-acting insulin analogs such as lispro (brand name *Humalog*, made by Eli Lilly and Company) and aspart (brand name *Novolog*/*Novorapid*, made by Novo Nordisk and *Apidra* made by Sanofi Aventis) are preferred by many clinicians over older regular insulin for meal coverage and high correction. Many people on MDI regimens carry insulin pens to inject their rapid-acting insulins instead of traditional syringes. Some people on an MDI regimen also use injection ports such as the I-port to minimize the number of daily skin punctures.
The other method of intensive/flexible insulin therapy is an insulin pump. It is a small mechanical device about the size of a deck of cards. It contains a syringe-like reservoir with about three days\' insulin supply. This is connected by thin, disposable, plastic tubing to a needle-like cannula inserted into the patient\'s skin and held in place by an adhesive patch. The infusion tubing and cannula must be removed and replaced every few days.
An insulin pump can be programmed to infuse a steady amount of rapid-acting insulin under the skin. This steady infusion is termed the basal rate and is designed to supply the background insulin needs. Each time the patient eats, he or she must press a button on the pump to deliver a specified dose of insulin to cover that meal. Extra insulin is also given the same way to correct a high glucose reading. Although current pumps can include a glucose sensor, they cannot automatically respond to meals or to rising or falling glucose levels.
Both MDI and pumping can achieve similarly excellent glycemic control. Some people prefer injections because they are less expensive than pumps and do not require the wearing of a continually attached device. However, the clinical literature is very clear that patients whose basal insulin requirements tend not to vary throughout the day or do not require dosage precision smaller than 0.5 IU, are much less likely to realize much significant advantage of pump therapy. Another perceived advantage of pumps is the freedom from syringes and injections, however, infusion sets still require less frequent injections to guide infusion sets into the subcutaneous tissue.
Intensive/flexible insulin therapy requires frequent blood glucose checking. To achieve the best balance of blood sugar with either intensive/flexible method, a patient must check his or her glucose level with a meter monitoring of blood glucose several times a day. This allows optimization of the basal insulin and meal coverage as well as correction of high glucose episodes.
## Advantages and disadvantages {#advantages_and_disadvantages}
The two primary advantages of intensive/flexible therapy over more traditional two or three injection regimens are:
1. greater flexibility of meal times, carbohydrate quantities, and physical activities, and
2. better glycemic control to reduce the incidence and severity of the complications of diabetes.
Major disadvantages of intensive/flexible therapy are that it requires greater amounts of education and effort to achieve the goals, and it increases the daily cost for glucose monitoring four or more times a day. This cost can substantially increase when the therapy is implemented with an insulin pump and/or continuous glucose monitor.
It is a common notion that more frequent hypoglycemia is a disadvantage of intensive/flexible regimens. The frequency of hypoglycemia increases with increasing effort to achieve normal blood glucoses with most insulin regimens, but hypoglycemia can be minimized with appropriate glucose targets and control strategies. The difficulties lie in remembering to test, estimating meal size, taking the meal bolus and eating within the prescribed time, and being aware of snacks and meals that are not the expected size. When implemented correctly, flexible regimens offer greater ability to achieve good glycemic control with easier accommodation to variations of eating and physical activity.
A 2020 Cochrane systematic review did not find enough evidence of reduction of cardiovascular mortality, non-fatal myocardial infarction or non-fatal stroke when comparing insulin to metformin monotherapy.
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# Intensive insulin therapy
## Semantics of changing care: why \"flexible\" is replacing \"intensive\" therapy {#semantics_of_changing_care_why_flexible_is_replacing_intensive_therapy}
Over the last two decades, the evidence that better glycemic control (i.e., keeping blood glucose and HbA1c levels as close to normal as possible) reduces the rates of many complications of diabetes has become overwhelming. As a result, diabetes specialists have expended increasing effort to help most people with diabetes achieve blood glucose levels as close to normal as achievable. It takes about the same amount of effort to achieve good glycemic control with a traditional two or three injection regimen as it does with flexible therapy: frequent glucose monitoring, attention to timing and amounts of meals. Many diabetes specialists no longer think of flexible insulin therapy as \"intensive\" or \"special\" treatment for a select group of patients but simply as standard care for most patients with type 1 diabetes.
## Treatment devices used {#treatment_devices_used}
The insulin pump is one device used in intensive insulinotherapy. The insulin pump is about the size of a beeper. It can be programmed to send a steady stream of insulin as *basal insulin*. It contains a reservoir or cartridge holding several days\' worth of insulin, the tiny battery-operated pump, and the computer chip that regulates how much insulin is pumped. The infusion set is a thin plastic tube with a fine needle at the end. There are also newer \"pods\" which do not require tubing. It carries the insulin from the pump to the infusion site beneath the skin. It sends a larger amount before eating meals as \"bolus\" doses.
The insulin pump replaces insulin injections. This device is useful for people who regularly forget to inject themselves or for people who don\'t like injections. This machine does the injecting by replacing the slow-acting insulin for basal needs with an ongoing infusion of rapid-acting insulin.
Basal insulin: the insulin that controls blood glucose levels between meals and overnight. It controls glucose in the fasting state.
Boluses: the insulin that is released when food is eaten or to correct a high reading.
Another device used in intensive insulinotherapy is the injection port. An injection port is a small disposable device, similar to the infusion set used with an insulin pump, configured to accept a syringe. Standard insulin injections are administered through the injection port. When using an injection port, the syringe needle always stays above the surface of the skin, thus reducing the number of skin punctures associated with intensive insulinotheraphy
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# Inverse function
`{{Functions}}`{=mediawiki} In mathematics, the **inverse function** of a function `{{Mvar|f}}`{=mediawiki} (also called the **inverse** of `{{Mvar|f}}`{=mediawiki}) is a function that undoes the operation of `{{Mvar|f}}`{=mediawiki}. The inverse of `{{Mvar|f}}`{=mediawiki} exists if and only if `{{Mvar|f}}`{=mediawiki} is bijective, and if it exists, is denoted by $f^{-1} .$
For a function $f\colon X\to Y$, its inverse $f^{-1}\colon Y\to X$ admits an explicit description: it sends each element $y\in Y$ to the unique element $x\in X$ such that `{{Math|1=''f''(''x'') = ''y''}}`{=mediawiki}.
As an example, consider the real-valued function of a real variable given by `{{math|1=''f''(''x'') = 5''x'' − 7}}`{=mediawiki}. One can think of `{{Mvar|f}}`{=mediawiki} as the function which multiplies its input by 5 then subtracts 7 from the result. To undo this, one adds 7 to the input, then divides the result by 5. Therefore, the inverse of `{{Mvar|f}}`{=mediawiki} is the function $f^{-1}\colon \R\to\R$ defined by $f^{-1}(y) = \frac{y+7}{5} .$
## Definitions
Let `{{mvar|f}}`{=mediawiki} be a function whose domain is the set `{{mvar|X}}`{=mediawiki}, and whose codomain is the set `{{mvar|Y}}`{=mediawiki}. Then `{{mvar|f}}`{=mediawiki} is *invertible* if there exists a function `{{mvar|g}}`{=mediawiki} from `{{mvar|Y}}`{=mediawiki} to `{{mvar|X}}`{=mediawiki} such that $g(f(x))=x$ for all $x\in X$ and $f(g(y))=y$ for all $y\in Y$.
If `{{mvar|f}}`{=mediawiki} is invertible, then there is exactly one function `{{mvar|g}}`{=mediawiki} satisfying this property. The function `{{mvar|g}}`{=mediawiki} is called the inverse of `{{mvar|f}}`{=mediawiki}, and is usually denoted as `{{math|''f''<sup> −1</sup>}}`{=mediawiki}, a notation introduced by John Frederick William Herschel in 1813.
The function `{{mvar|f}}`{=mediawiki} is invertible if and only if it is bijective. This is because the condition $g(f(x))=x$ for all $x\in X$ implies that `{{mvar|f}}`{=mediawiki} is injective, and the condition $f(g(y))=y$ for all $y\in Y$ implies that `{{mvar|f}}`{=mediawiki} is surjective.
The inverse function `{{math|''f''<sup> −1</sup>}}`{=mediawiki} to `{{mvar|f}}`{=mediawiki} can be explicitly described as the function
$$f^{-1}(y)=(\text{the unique element }x\in X\text{ such that }f(x)=y)$$.
### `{{anchor|Compositional inverse}}`{=mediawiki}Inverses and composition {#inverses_and_composition}
Recall that if `{{mvar|f}}`{=mediawiki} is an invertible function with domain `{{mvar|X}}`{=mediawiki} and codomain `{{mvar|Y}}`{=mediawiki}, then
: $f^{-1}\left(f(x)\right) = x$, for every $x \in X$ and $f\left(f^{-1}(y)\right) = y$ for every $y \in Y$.
Using the composition of functions, this statement can be rewritten to the following equations between functions:
: $f^{-1} \circ f = \operatorname{id}_X$ and $f \circ f^{-1} = \operatorname{id}_Y,$
where `{{math|id<sub>''X''</sub>}}`{=mediawiki} is the identity function on the set `{{mvar|X}}`{=mediawiki}; that is, the function that leaves its argument unchanged. In category theory, this statement is used as the definition of an inverse morphism.
Considering function composition helps to understand the notation `{{math|''f''<sup> −1</sup>}}`{=mediawiki}. Repeatedly composing a function `{{math|''f'': ''X''→''X''}}`{=mediawiki} with itself is called iteration. If `{{mvar|f}}`{=mediawiki} is applied `{{mvar|n}}`{=mediawiki} times, starting with the value `{{mvar|x}}`{=mediawiki}, then this is written as `{{math|''f''<sup> ''n''</sup>(''x'')}}`{=mediawiki}; so `{{math|''f''<sup> 2</sup>(''x'') {{=}}`{=mediawiki} *f* (*f* (*x*))}}, etc. Since `{{math|''f''<sup> −1</sup>(''f'' (''x'')) {{=}}`{=mediawiki} *x*}}, composing `{{math|''f''<sup> −1</sup>}}`{=mediawiki} and `{{math|''f''<sup> ''n''</sup>}}`{=mediawiki} yields `{{math|''f''<sup> ''n''−1</sup>}}`{=mediawiki}, \"undoing\" the effect of one application of `{{mvar|f}}`{=mediawiki}.
### Notation
While the notation `{{math|''f''<sup> −1</sup>(''x'')}}`{=mediawiki} might be misunderstood, `{{math|(''f''(''x''))<sup>−1</sup>}}`{=mediawiki} certainly denotes the multiplicative inverse of `{{math|''f''(''x'')}}`{=mediawiki} and has nothing to do with the inverse function of `{{mvar|f}}`{=mediawiki}. The notation $f^{\langle -1\rangle}$ might be used for the inverse function to avoid ambiguity with the multiplicative inverse.
In keeping with the general notation, some English authors use expressions like `{{math|sin<sup>−1</sup>(''x'')}}`{=mediawiki} to denote the inverse of the sine function applied to `{{mvar|x}}`{=mediawiki} (actually a partial inverse; see below). Other authors feel that this may be confused with the notation for the multiplicative inverse of `{{math|sin (''x'')}}`{=mediawiki}, which can be denoted as `{{math|(sin (''x''))<sup>−1</sup>}}`{=mediawiki}. To avoid any confusion, an inverse trigonometric function is often indicated by the prefix \"arc\" (for Latin *arcus*). For instance, the inverse of the sine function is typically called the arcsine function, written as `{{math|[[arcsin]](''x'')}}`{=mediawiki}. Similarly, the inverse of a hyperbolic function is indicated by the prefix \"ar\" (for Latin *ārea*). For instance, the inverse of the hyperbolic sine function is typically written as `{{math|[[arsinh]](''x'')}}`{=mediawiki}. The expressions like `{{math|sin<sup>−1</sup>(''x'')}}`{=mediawiki} can still be useful to distinguish the multivalued inverse from the partial inverse: $\sin^{-1}(x) = \{(-1)^n \arcsin(x) + \pi n : n \in \mathbb Z\}$. Other inverse special functions are sometimes prefixed with the prefix \"inv\", if the ambiguity of the `{{math|''f''<sup> −1</sup>}}`{=mediawiki} notation should be avoided.
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# Inverse function
## Examples
### Squaring and square root functions {#squaring_and_square_root_functions}
The function `{{math|''f'': '''R''' → [0,∞)}}`{=mediawiki} given by `{{math|1=''f''(''x'') = ''x''<sup>2</sup>}}`{=mediawiki} is not injective because $(-x)^2=x^2$ for all $x\in\R$. Therefore, `{{Mvar|f}}`{=mediawiki} is not invertible.
If the domain of the function is restricted to the nonnegative reals, that is, we take the function $f\colon [0,\infty)\to [0,\infty);\ x\mapsto x^2$ with the same *rule* as before, then the function is bijective and so, invertible. The inverse function here is called the *(positive) square root function* and is denoted by $x\mapsto\sqrt x$.
### Standard inverse functions {#standard_inverse_functions}
The following table shows several standard functions and their inverses:
Function `{{math|''f''(''x'')}}`{=mediawiki} Inverse `{{math|''f''<sup> −1</sup>(''y'')}}`{=mediawiki} Notes
-------------------------------------------------- ------------------------------------------------------------------- -----------------------------------------------------------------------------------------------------------------------
(i.e. `{{math|''x''<sup>−1</sup>}}`{=mediawiki}) (i.e. `{{math|''y''<sup>−1</sup>}}`{=mediawiki})
$\sqrt[p]y$ (i.e. `{{math|''y''<sup>1/''p''</sup>}}`{=mediawiki}) integer `{{math|''p'' > 0}}`{=mediawiki}; `{{math|''x'', ''y'' ≥ 0}}`{=mediawiki} if `{{math|p}}`{=mediawiki} is even
and `{{math|''a'' > 0}}`{=mediawiki} and `{{math|''a'' ≠ 1}}`{=mediawiki}
and `{{math|''y'' ≥ −1/''e''}}`{=mediawiki}
trigonometric functions inverse trigonometric functions various restrictions (see table below)
hyperbolic functions inverse hyperbolic functions various restrictions
: Inverse arithmetic functions
### Formula for the inverse {#formula_for_the_inverse}
Many functions given by algebraic formulas possess a formula for their inverse. This is because the inverse $f^{-1}$ of an invertible function $f\colon\R\to\R$ has an explicit description as
: $f^{-1}(y)=(\text{the unique element }x\in \R\text{ such that }f(x)=y)$.
This allows one to easily determine inverses of many functions that are given by algebraic formulas. For example, if `{{mvar|f}}`{=mediawiki} is the function
: $f(x) = (2x + 8)^3$
then to determine $f^{-1}(y)$ for a real number `{{Mvar|y}}`{=mediawiki}, one must find the unique real number `{{mvar|x}}`{=mediawiki} such that `{{math|1= (2''x'' + 8)<sup>3</sup> = ''y''}}`{=mediawiki}. This equation can be solved:
: \\begin{align}
` y & = (2x+8)^3 \\`\
` \sqrt[3]{y} & = 2x + 8 \\`
\\sqrt\[3\]{y} - 8 & = 2x \\\\ \\dfrac{\\sqrt\[3\]{y} - 8}{2} & = x . \\end{align}
Thus the inverse function `{{math|''f''<sup> −1</sup>}}`{=mediawiki} is given by the formula
: $f^{-1}(y) = \frac{\sqrt[3]{y} - 8} 2.$
Sometimes, the inverse of a function cannot be expressed by a closed-form formula. For example, if `{{mvar|f}}`{=mediawiki} is the function
: $f(x) = x - \sin x ,$
then `{{mvar|f}}`{=mediawiki} is a bijection, and therefore possesses an inverse function `{{math|''f''<sup> −1</sup>}}`{=mediawiki}. The formula for this inverse has an expression as an infinite sum:
: f\^{-1}(y) =
\\sum\_{n=1}\^\\infty
`\frac{y^{n/3}}{n!} \lim_{ \theta \to 0} \left(`\
`\frac{\mathrm{d}^{\,n-1}}{\mathrm{d} \theta^{\,n-1}} \left(`\
`\frac \theta { \sqrt[3]{ \theta - \sin( \theta )} } \right)^n`
\\right).
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# Inverse function
## Properties
Since a function is a special type of binary relation, many of the properties of an inverse function correspond to properties of converse relations.
### Uniqueness
If an inverse function exists for a given function `{{mvar|f}}`{=mediawiki}, then it is unique. This follows since the inverse function must be the converse relation, which is completely determined by `{{mvar|f}}`{=mediawiki}.
### Symmetry
There is a symmetry between a function and its inverse. Specifically, if `{{mvar|f}}`{=mediawiki} is an invertible function with domain `{{mvar|X}}`{=mediawiki} and codomain `{{mvar|Y}}`{=mediawiki}, then its inverse `{{math|''f''<sup> −1</sup>}}`{=mediawiki} has domain `{{mvar|Y}}`{=mediawiki} and image `{{mvar|X}}`{=mediawiki}, and the inverse of `{{math|''f''<sup> −1</sup>}}`{=mediawiki} is the original function `{{mvar|f}}`{=mediawiki}. In symbols, for functions `{{math|''f'':''X'' → ''Y''}}`{=mediawiki} and `{{math|''f''<sup>−1</sup>:''Y'' → ''X''}}`{=mediawiki},
$$f^{-1}\circ f = \operatorname{id}_X$$ and $f \circ f^{-1} = \operatorname{id}_Y.$
This statement is a consequence of the implication that for `{{mvar|f}}`{=mediawiki} to be invertible it must be bijective. The involutory nature of the inverse can be concisely expressed by
$$\left(f^{-1}\right)^{-1} = f.$$
The inverse of a composition of functions is given by
$$(g \circ f)^{-1} = f^{-1} \circ g^{-1}.$$ Notice that the order of `{{mvar|g}}`{=mediawiki} and `{{mvar|f}}`{=mediawiki} have been reversed; to undo `{{mvar|f}}`{=mediawiki} followed by `{{mvar|g}}`{=mediawiki}, we must first undo `{{mvar|g}}`{=mediawiki}, and then undo `{{mvar|f}}`{=mediawiki}.
For example, let `{{math|1= ''f''(''x'') = 3''x''}}`{=mediawiki} and let `{{math|1= ''g''(''x'') = ''x'' + 5}}`{=mediawiki}. Then the composition `{{math| ''g'' ∘ ''f''}}`{=mediawiki} is the function that first multiplies by three and then adds five,
: $(g \circ f)(x) = 3x + 5.$
To reverse this process, we must first subtract five, and then divide by three,
: $(g \circ f)^{-1}(x) = \tfrac13(x - 5).$
This is the composition `{{math| (''f''<sup> −1</sup> ∘ ''g''<sup> −1</sup>)(''x'')}}`{=mediawiki}.
### Self-inverses {#self_inverses}
If `{{mvar|X}}`{=mediawiki} is a set, then the identity function on `{{mvar|X}}`{=mediawiki} is its own inverse:
: ${\operatorname{id}_X}^{-1} = \operatorname{id}_X.$
More generally, a function `{{math| ''f'' : ''X'' → ''X''}}`{=mediawiki} is equal to its own inverse, if and only if the composition `{{math| ''f'' ∘ ''f''}}`{=mediawiki} is equal to `{{math|id<sub>''X''</sub>}}`{=mediawiki}. Such a function is called an involution.
### Graph of the inverse {#graph_of_the_inverse}
If `{{mvar|f}}`{=mediawiki} is invertible, then the graph of the function
: $y = f^{-1}(x)$
is the same as the graph of the equation
: $x = f(y) .$
This is identical to the equation `{{math|1= ''y'' = ''f''(''x'')}}`{=mediawiki} that defines the graph of `{{mvar|f}}`{=mediawiki}, except that the roles of `{{mvar|x}}`{=mediawiki} and `{{mvar|y}}`{=mediawiki} have been reversed. Thus the graph of `{{math|''f''<sup> −1</sup>}}`{=mediawiki} can be obtained from the graph of `{{mvar|f}}`{=mediawiki} by switching the positions of the `{{mvar|x}}`{=mediawiki} and `{{mvar|y}}`{=mediawiki} axes. This is equivalent to reflecting the graph across the line `{{math|1= ''y'' = ''x''}}`{=mediawiki}.
### Inverses and derivatives {#inverses_and_derivatives}
By the inverse function theorem, a continuous function of a single variable $f\colon A\to\mathbb{R}$ (where $A\subseteq\mathbb{R}$) is invertible on its range (image) if and only if it is either strictly increasing or decreasing (with no local maxima or minima). For example, the function
: $f(x) = x^3 + x$
is invertible, since the derivative `{{math|1= ''f′''(''x'') = 3''x''<sup>2</sup> + 1 }}`{=mediawiki} is always positive.
If the function `{{mvar|f}}`{=mediawiki} is differentiable on an interval `{{mvar|I}}`{=mediawiki} and `{{math| ''f′''(''x'') ≠ 0}}`{=mediawiki} for each `{{math|''x'' ∈ ''I''}}`{=mediawiki}, then the inverse `{{math|''f''<sup> −1</sup>}}`{=mediawiki} is differentiable on `{{math|''f''(''I'')}}`{=mediawiki}. If `{{math|1= ''y'' = ''f''(''x'')}}`{=mediawiki}, the derivative of the inverse is given by the inverse function theorem,
: $\left(f^{-1}\right)^\prime (y) = \frac{1}{f'\left(x \right)}.$
Using Leibniz\'s notation the formula above can be written as
: $\frac{dx}{dy} = \frac{1}{dy / dx}.$
This result follows from the chain rule (see the article on inverse functions and differentiation).
The inverse function theorem can be generalized to functions of several variables. Specifically, a continuously differentiable multivariable function `{{math| ''f '': '''R'''<sup>''n''</sup> → '''R'''<sup>''n''</sup>}}`{=mediawiki} is invertible in a neighborhood of a point `{{mvar|p}}`{=mediawiki} as long as the Jacobian matrix of `{{mvar|f}}`{=mediawiki} at `{{mvar|p}}`{=mediawiki} is invertible. In this case, the Jacobian of `{{math|''f''<sup> −1</sup>}}`{=mediawiki} at `{{math|''f''(''p'')}}`{=mediawiki} is the matrix inverse of the Jacobian of `{{mvar|f}}`{=mediawiki} at `{{mvar|p}}`{=mediawiki}.
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# Inverse function
## Real-world examples {#real_world_examples}
- Let `{{mvar|f}}`{=mediawiki} be the function that converts a temperature in degrees Celsius to a temperature in degrees Fahrenheit, $F = f(C) = \tfrac95 C + 32 ;$ then its inverse function converts degrees Fahrenheit to degrees Celsius, $C = f^{-1}(F) = \tfrac59 (F - 32) ,$ since
\\begin{align} f\^{-1} (f(C)) = {} & f\^{-1}\\left( \\tfrac95 C + 32 \\right) = \\tfrac59 \\left( (\\tfrac95 C + 32 ) - 32 \\right) = C, \\\\ & \\text{for every value of } C, \\text{ and } \\\\\[6pt\] f\\left(f\^{-1}(F)\\right) = {} & f\\left(\\tfrac59 (F - 32)\\right) = \\tfrac95 \\left(\\tfrac59 (F - 32)\\right) + 32 = F, \\\\ & \\text{for every value of } F. \\end{align}
- Suppose `{{mvar|f}}`{=mediawiki} assigns each child in a family its birth year. An inverse function would output which child was born in a given year. However, if the family has children born in the same year (for instance, twins or triplets, etc.) then the output cannot be known when the input is the common birth year. As well, if a year is given in which no child was born then a child cannot be named. But if each child was born in a separate year, and if we restrict attention to the three years in which a child was born, then we do have an inverse function. For example, \\begin{align}
`f(\text{Allan})&=2005 , \quad & f(\text{Brad})&=2007 , \quad & f(\text{Cary})&=2001 \\`\
`f^{-1}(2005)&=\text{Allan} , \quad & f^{-1}(2007)&=\text{Brad} , \quad & f^{-1}(2001)&=\text{Cary}`
\\end{align}
- Let `{{mvar|R}}`{=mediawiki} be the function that leads to an `{{mvar|x}}`{=mediawiki} percentage rise of some quantity, and `{{mvar|F}}`{=mediawiki} be the function producing an `{{mvar|x}}`{=mediawiki} percentage fall. Applied to \$100 with `{{mvar|x}}`{=mediawiki} = 10%, we find that applying the first function followed by the second does not restore the original value of \$100, demonstrating the fact that, despite appearances, these two functions are not inverses of each other.
- The formula to calculate the pH of a solution is `{{math|1=pH = −log<sub>10</sub>[H<sup>+</sup>]}}`{=mediawiki}. In many cases we need to find the concentration of acid from a pH measurement. The inverse function `{{math|1=[H<sup>+</sup>] = 10<sup>−pH</sup>}}`{=mediawiki} is used.
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# Inverse function
## Generalizations
### Partial inverses {#partial_inverses}
Even if a function `{{mvar|f}}`{=mediawiki} is not one-to-one, it may be possible to define a **partial inverse** of `{{mvar|f}}`{=mediawiki} by restricting the domain. For example, the function
: $f(x) = x^2$
is not one-to-one, since `{{math|1= ''x''<sup>2</sup> = (−''x'')<sup>2</sup>}}`{=mediawiki}. However, the function becomes one-to-one if we restrict to the domain `{{math| ''x'' ≥ 0}}`{=mediawiki}, in which case
: $f^{-1}(y) = \sqrt{y} .$
(If we instead restrict to the domain `{{math| ''x'' ≤ 0}}`{=mediawiki}, then the inverse is the negative of the square root of `{{mvar|y}}`{=mediawiki}.)
### Full inverses {#full_inverses}
Alternatively, there is no need to restrict the domain if we are content with the inverse being a multivalued function:
: $f^{-1}(y) = \pm\sqrt{y} .$
Sometimes, this multivalued inverse is called the **full inverse** of `{{mvar|f}}`{=mediawiki}, and the portions (such as `{{sqrt|{{mvar|x}}}}`{=mediawiki} and −`{{sqrt|{{mvar|x}}}}`{=mediawiki}) are called *branches*. The most important branch of a multivalued function (e.g. the positive square root) is called the *principal branch*, and its value at `{{mvar|y}}`{=mediawiki} is called the *principal value* of `{{math|''f''<sup> −1</sup>(''y'')}}`{=mediawiki}.
For a continuous function on the real line, one branch is required between each pair of local extrema. For example, the inverse of a cubic function with a local maximum and a local minimum has three branches (see the adjacent picture).
### Trigonometric inverses {#trigonometric_inverses}
The above considerations are particularly important for defining the inverses of trigonometric functions. For example, the sine function is not one-to-one, since
: $\sin(x + 2\pi) = \sin(x)$
for every real `{{mvar|x}}`{=mediawiki} (and more generally `{{math|1= sin(''x'' + 2{{pi}}''n'') = sin(''x'')}}`{=mediawiki} for every integer `{{mvar|n}}`{=mediawiki}). However, the sine is one-to-one on the interval `{{closed-closed|−{{sfrac|{{pi}}|2}}, {{sfrac|{{pi}}|2}}}}`{=mediawiki}, and the corresponding partial inverse is called the arcsine. This is considered the principal branch of the inverse sine, so the principal value of the inverse sine is always between −`{{sfrac|{{pi}}|2}}`{=mediawiki} and `{{sfrac|{{pi}}|2}}`{=mediawiki}. The following table describes the principal branch of each inverse trigonometric function:
function Range of usual principal value
---------- --------------------------------
arcsin
arccos
arctan
arccot
arcsec
arccsc
### Left and right inverses {#left_and_right_inverses}
Function composition on the left and on the right need not coincide. In general, the conditions
1. \"There exists `{{mvar|g}}`{=mediawiki} such that `{{math|''g''(''f''(''x'')){{=}}`{=mediawiki}*x*}}\" and
2. \"There exists `{{mvar|g}}`{=mediawiki} such that `{{math|''f''(''g''(''x'')){{=}}`{=mediawiki}*x*}}\"
imply different properties of `{{mvar|f}}`{=mediawiki}. For example, let `{{math|''f'': '''R''' → {{closed-open|0, ∞}}}}`{=mediawiki} denote the squaring map, such that `{{math|1=''f''(''x'') = ''x''<sup>2</sup>}}`{=mediawiki} for all `{{mvar|x}}`{=mediawiki} in `{{math|'''R'''}}`{=mediawiki}, and let `{{math|{{mvar|g}}: {{closed-open|0, ∞}} → '''R'''}}`{=mediawiki} denote the square root map, such that `{{math|''g''(''x'') {{=}}`{=mediawiki} }}`{{radic|{{mvar|x}}}}`{=mediawiki} for all `{{math|''x'' ≥ 0}}`{=mediawiki}. Then `{{math|1=''f''(''g''(''x'')) = ''x''}}`{=mediawiki} for all `{{mvar|x}}`{=mediawiki} in `{{closed-open|0, ∞}}`{=mediawiki}; that is, `{{mvar|g}}`{=mediawiki} is a right inverse to `{{mvar|f}}`{=mediawiki}. However, `{{mvar|g}}`{=mediawiki} is not a left inverse to `{{mvar|f}}`{=mediawiki}, since, e.g., `{{math|1=''g''(''f''(−1)) = 1 ≠ −1}}`{=mediawiki}.
#### Left inverses {#left_inverses}
If `{{math|''f'': ''X'' → ''Y''}}`{=mediawiki}, a **left inverse** for `{{mvar|f}}`{=mediawiki} (or *retraction* of `{{mvar|f}}`{=mediawiki} ) is a function `{{math| ''g'': ''Y'' → ''X''}}`{=mediawiki} such that composing `{{mvar|f}}`{=mediawiki} with `{{mvar|g}}`{=mediawiki} from the left gives the identity function $g \circ f = \operatorname{id}_X\text{.}$ That is, the function `{{mvar|g}}`{=mediawiki} satisfies the rule
: If `{{math|''f''(''x''){{=}}`{=mediawiki}*y*}}, then `{{math|''g''(''y''){{=}}`{=mediawiki}*x*}}.
The function `{{mvar|g}}`{=mediawiki} must equal the inverse of `{{mvar|f}}`{=mediawiki} on the image of `{{mvar|f}}`{=mediawiki}, but may take any values for elements of `{{mvar|Y}}`{=mediawiki} not in the image.
A function `{{mvar|f}}`{=mediawiki} with nonempty domain is injective if and only if it has a left inverse. An elementary proof runs as follows:
- If `{{mvar|g}}`{=mediawiki} is the left inverse of `{{mvar|f}}`{=mediawiki}, and `{{math|1=''f''(''x'') = ''f''(''y'')}}`{=mediawiki}, then `{{math|1=''g''(''f''(''x'')) = ''g''(''f''(''y'')) = ''x'' = ''y''}}`{=mediawiki}.
- If nonempty `{{math|''f'': ''X'' → ''Y''}}`{=mediawiki} is injective, construct a left inverse `{{math|''g'': ''Y'' → ''X''}}`{=mediawiki} as follows: for all `{{math|''y'' ∈ ''Y''}}`{=mediawiki}, if `{{mvar|y}}`{=mediawiki} is in the image of `{{mvar|f}}`{=mediawiki}, then there exists `{{math|''x'' ∈ ''X''}}`{=mediawiki} such that `{{math|1=''f''(''x'') = ''y''}}`{=mediawiki}. Let `{{math|1=''g''(''y'') = ''x''}}`{=mediawiki}; this definition is unique because `{{mvar|f}}`{=mediawiki} is injective. Otherwise, let `{{math|''g''(''y'')}}`{=mediawiki} be an arbitrary element of `{{mvar|X}}`{=mediawiki}.
For all `{{math|''x'' ∈ ''X''}}`{=mediawiki}, `{{math|''f''(''x'')}}`{=mediawiki} is in the image of `{{mvar|f}}`{=mediawiki}. By construction, `{{math|1=''g''(''f''(''x'')) = ''x''}}`{=mediawiki}, the condition for a left inverse.
In classical mathematics, every injective function `{{mvar|f}}`{=mediawiki} with a nonempty domain necessarily has a left inverse; however, this may fail in constructive mathematics. For instance, a left inverse of the inclusion `{{math|{0,1} → '''R'''}}`{=mediawiki} of the two-element set in the reals violates indecomposability by giving a retraction of the real line to the set `{{math|{0,1{{)}}`{=mediawiki}}}.
#### Right inverses {#right_inverses}
A **right inverse** for `{{mvar|f}}`{=mediawiki} (or *section* of `{{mvar|f}}`{=mediawiki} ) is a function `{{math| ''h'': ''Y'' → ''X''}}`{=mediawiki} such that
: $f \circ h = \operatorname{id}_Y .$
That is, the function `{{mvar|h}}`{=mediawiki} satisfies the rule
: If $\displaystyle h(y) = x$, then $\displaystyle f(x) = y .$
Thus, `{{math|''h''(''y'')}}`{=mediawiki} may be any of the elements of `{{mvar|X}}`{=mediawiki} that map to `{{mvar|y}}`{=mediawiki} under `{{mvar|f}}`{=mediawiki}.
A function `{{mvar|f}}`{=mediawiki} has a right inverse if and only if it is surjective (though constructing such an inverse in general requires the axiom of choice).
: If `{{mvar|h}}`{=mediawiki} is the right inverse of `{{mvar|f}}`{=mediawiki}, then `{{mvar|f}}`{=mediawiki} is surjective. For all $y \in Y$, there is $x = h(y)$ such that $f(x) = f(h(y)) = y$.
: If `{{mvar|f}}`{=mediawiki} is surjective, `{{mvar|f}}`{=mediawiki} has a right inverse `{{mvar|h}}`{=mediawiki}, which can be constructed as follows: for all $y \in Y$, there is at least one $x \in X$ such that $f(x) = y$ (because `{{mvar|f}}`{=mediawiki} is surjective), so we choose one to be the value of `{{math|''h''(''y'')}}`{=mediawiki}.
#### Two-sided inverses {#two_sided_inverses}
An inverse that is both a left and right inverse (a **two-sided inverse**), if it exists, must be unique. In fact, if a function has a left inverse and a right inverse, they are both the same two-sided inverse, so it can be called **the inverse**.
: If $g$ is a left inverse and $h$ a right inverse of $f$, for all $y \in Y$, $g(y) = g(f(h(y)) = h(y)$.
A function has a two-sided inverse if and only if it is bijective.
: A bijective function `{{mvar|f}}`{=mediawiki} is injective, so it has a left inverse (if `{{mvar|f}}`{=mediawiki} is the empty function, $f \colon \varnothing \to \varnothing$ is its own left inverse). `{{mvar|f}}`{=mediawiki} is surjective, so it has a right inverse. By the above, the left and right inverse are the same.
: If `{{mvar|f}}`{=mediawiki} has a two-sided inverse `{{mvar|g}}`{=mediawiki}, then `{{mvar|g}}`{=mediawiki} is a left inverse and right inverse of `{{mvar|f}}`{=mediawiki}, so `{{mvar|f}}`{=mediawiki} is injective and surjective.
### Preimages
If `{{math|''f'': ''X'' → ''Y''}}`{=mediawiki} is any function (not necessarily invertible), the **preimage** (or **inverse image**) of an element `{{math| ''y'' ∈ ''Y''}}`{=mediawiki} is defined to be the set of all elements of `{{mvar|X}}`{=mediawiki} that map to `{{mvar|y}}`{=mediawiki}:
: $f^{-1}(y) = \left\{ x\in X : f(x) = y \right\} .$
The preimage of `{{mvar|y}}`{=mediawiki} can be thought of as the image of `{{mvar|y}}`{=mediawiki} under the (multivalued) full inverse of the function `{{mvar|f}}`{=mediawiki}.
The notion can be generalized to subsets of the range. Specifically, if `{{mvar|S}}`{=mediawiki} is any subset of `{{mvar|Y}}`{=mediawiki}, the preimage of `{{mvar|S}}`{=mediawiki}, denoted by $f^{-1}(S)$, is the set of all elements of `{{mvar|X}}`{=mediawiki} that map to `{{mvar|S}}`{=mediawiki}:
: $f^{-1}(S) = \left\{ x\in X : f(x) \in S \right\} .$
For example, take the function `{{math|''f'': '''R''' → '''R'''; ''x'' ↦ ''x''<sup>2</sup>}}`{=mediawiki}. This function is not invertible as it is not bijective, but preimages may be defined for subsets of the codomain, e.g.
: $f^{-1}(\left\{1,4,9,16\right\}) = \left\{-4,-3,-2,-1,1,2,3,4\right\}$.
The original notion and its generalization are related by the identity $f^{-1}(y) = f^{-1}(\{y\}),$ The preimage of a single element `{{math| ''y'' ∈ ''Y''}}`{=mediawiki} -- a singleton set `{{math|{''y''} }}`{=mediawiki} -- is sometimes called the *fiber* of `{{mvar|y}}`{=mediawiki}. When `{{mvar|Y}}`{=mediawiki} is the set of real numbers, it is common to refer to `{{math|''f''<sup> −1</sup>({''y''})}}`{=mediawiki} as a *level set*
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# If and only if
In logic and related fields such as mathematics and philosophy, \"**if and only if**\" (often shortened as \"**iff**\") is paraphrased by the biconditional, a logical connective between statements. The biconditional is true in two cases, where either both statements are true or both are false. The connective is biconditional (a statement of **material equivalence** ), and can be likened to the standard material conditional (\"only if\", equal to \"if \... then\") combined with its reverse (\"if\"); hence the name. The result is that the truth of either one of the connected statements requires the truth of the other (i.e. either both statements are true, or both are false), though it is controversial whether the connective thus defined is properly rendered by the English \"if and only if\"---with its pre-existing meaning. For example, *P if and only if Q* means that *P* is true whenever *Q* is true, and the only case in which *P* is true is if *Q* is also true, whereas in the case of *P if Q*, there could be other scenarios where *P* is true and *Q* is false.
In writing, phrases commonly used as alternatives to P \"if and only if\" Q include: *Q is necessary and sufficient for P*, *for P it is necessary and sufficient that Q*, *P is equivalent (or materially equivalent) to Q* (compare with material implication), *P precisely if Q*, *P precisely (or exactly) when Q*, *P exactly in case Q*, and *P just in case Q*. Some authors regard \"iff\" as unsuitable in formal writing; others consider it a \"borderline case\" and tolerate its use. In logical formulae, logical symbols, such as $\leftrightarrow$ and $\Leftrightarrow$, are used instead of these phrases; see `{{Section link||Notation}}`{=mediawiki} below.
## Definition
The truth table of *P* $\leftrightarrow$ *Q* is as follows:
It is equivalent to that produced by the XNOR gate, and opposite to that produced by the XOR gate.
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# If and only if
## Usage
### Notation
The corresponding logical symbols are \"$\leftrightarrow$\", \"$\Leftrightarrow$\", and $\equiv$, and sometimes \"iff\". These are usually treated as equivalent. However, some texts of mathematical logic (particularly those on first-order logic, rather than propositional logic) make a distinction between these, in which the first, $\leftrightarrow$, is used as a symbol in logic formulas, while $\Leftrightarrow$ or $\equiv$ is used in reasoning about those logic formulas (e.g., in metalogic). In Łukasiewicz\'s Polish notation, it is the prefix symbol $E$.
Another term for the logical connective, i.e., the symbol in logic formulas, is exclusive nor.
In TeX, \"if and only if\" is shown as a long double arrow: $\iff$ via command \\iff or \\Longleftrightarrow.
### Proofs
In most logical systems, one proves a statement of the form \"P iff Q\" by proving either \"if P, then Q\" and \"if Q, then P\", or \"if P, then Q\" and \"if not-P, then not-Q\". Proving these pairs of statements sometimes leads to a more natural proof, since there are not obvious conditions in which one would infer a biconditional directly. An alternative is to prove the disjunction \"(P and Q) or (not-P and not-Q)\", which itself can be inferred directly from either of its disjuncts---that is, because \"iff\" is truth-functional, \"P iff Q\" follows if P and Q have been shown to be both true, or both false.
### Origin of iff and pronunciation {#origin_of_iff_and_pronunciation}
Usage of the abbreviation \"iff\" first appeared in print in John L. Kelley\'s 1955 book *General Topology*. Its invention is often credited to Paul Halmos, who wrote \"I invented \'iff,\' for \'if and only if\'---but I could never believe I was really its first inventor.\"
It is somewhat unclear how \"iff\" was meant to be pronounced. In current practice, the single \'word\' \"iff\" is almost always read as the four words \"if and only if\". However, in the preface of *General Topology*, Kelley suggests that it should be read differently: \"In some cases where mathematical content requires \'if and only if\' and euphony demands something less I use Halmos\' \'iff{{\'\"}}. The authors of one discrete mathematics textbook suggest: \"Should you need to pronounce iff, really hang on to the \'ff\' so that people hear the difference from \'if{{\'\"}}, implying that \"iff\" could be pronounced as `{{IPA|[ɪfː]}}`{=mediawiki}.
### Usage in definitions {#usage_in_definitions}
Conventionally, definitions are \"if and only if\" statements; some texts --- such as Kelley\'s *General Topology* --- follow this convention, and use \"if and only if\" or *iff* in definitions of new terms. However, this usage of \"if and only if\" is relatively uncommon and overlooks the linguistic fact that the \"if\" of a definition is interpreted as meaning \"if and only if\". The majority of textbooks, research papers and articles (including English Wikipedia articles) follow the linguistic convention of interpreting \"if\" as \"if and only if\" whenever a mathematical definition is involved (as in \"a topological space is compact if every open cover has a finite subcover\"). Moreover, in the case of a recursive definition, the *only if* half of the definition is interpreted as a sentence in the metalanguage stating that the sentences in the definition of a predicate are the *only sentences* determining the extension of the predicate.
## In terms of Euler diagrams {#in_terms_of_euler_diagrams}
<File:Example> of A is a proper subset of B.svg\|*A* is a proper subset of *B*. A number is in *A* only if it is in *B*; a number is in *B* if it is in *A*. <File:Example> of C is no proper subset of B.svg\|*C* is a subset but not a proper subset of *B*. A number is in *B* if and only if it is in *C*, and a number is in *C* if and only if it is in *B*.
Euler diagrams show logical relationships among events, properties, and so forth. \"P only if Q\", \"if P then Q\", and \"P→Q\" all mean that P is a subset, either proper or improper, of Q. \"P if Q\", \"if Q then P\", and Q→P all mean that Q is a proper or improper subset of P. \"P if and only if Q\" and \"Q if and only if P\" both mean that the sets P and Q are identical to each other.
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# If and only if
## More general usage {#more_general_usage}
*Iff* is used outside the field of logic as well. Wherever logic is applied, especially in mathematical discussions, it has the same meaning as above: it is an abbreviation for *if and only if*, indicating that one statement is both necessary and sufficient for the other. This is an example of mathematical jargon (although, as noted above, *if* is more often used than *iff* in statements of definition).
The elements of *X* are *all and only* the elements of *Y* means: \"For any *z* in the domain of discourse, *z* is in *X* if and only if *z* is in *Y*.\"
## When \"if\" means \"if and only if\" {#when_if_means_if_and_only_if}
In their *Artificial Intelligence: A Modern Approach*, Russell and Norvig note (page 282), in effect, that it is often more natural to express *if and only if* as *if* together with a \"database (or logic programming) semantics\". They give the example of the English sentence \"Richard has two brothers, Geoffrey and John\".
In a database or logic program, this could be represented simply by two sentences:
: Brother(Richard, Geoffrey).
: Brother(Richard, John).
The database semantics interprets the database (or program) as containing *all* and *only* the knowledge relevant for problem solving in a given domain. It interprets *only if* as expressing in the metalanguage that the sentences in the database represent the *only* knowledge that should be considered when drawing conclusions from the database.
In first-order logic (FOL) with the standard semantics, the same English sentence would need to be represented, using *if and only if*, with *only if* interpreted in the object language, in some such form as:
$$\forall$$ X(Brother(Richard, X) iff X = Geoffrey or X = John).
: Geoffrey ≠ John.
Compared with the standard semantics for FOL, the database semantics has a more efficient implementation. Instead of reasoning with sentences of the form:
: *conclusion iff conditions*
it uses sentences of the form:
: *conclusion if conditions*
to reason forwards from *conditions* to *conclusions* or backwards from *conclusions* to *conditions*.
The database semantics is analogous to the legal principle expressio unius est exclusio alterius (the express mention of one thing excludes all others). Moreover, it underpins the application of logic programming to the representation of legal texts and legal reasoning
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# Isaac Ambrose
**Isaac Ambrose** (1604 -- 20 January 1664) was an English Puritan divine. He graduated with a BA from Brasenose College, Oxford, on 1624. He obtained the curacy of St Edmund's Church, Castleton, Derbyshire, in 1627. He was one of king\'s four preachers in Lancashire in 1631. He was twice imprisoned by commissioners of array. He worked for the establishment of Presbyterianism; successively at Leeds, Preston, and Garstang, whence he was ejected for nonconformity in 1662. He also published religious works.
## Biography
Ambrose was born in 1604. He was the son of Richard Ambrose, vicar of Ormskirk, and was probably descended from the Ambroses of Lowick in Furness, a well-known Roman Catholic family. He entered Brasenose College, Oxford, in 1621, in his seventeenth year.
Having graduated B.A. in 1624 and been ordained, Ambroses received in 1627 the little cure of Castleton in Derbyshire. By the influence of William Russell, earl of Bedford, he was appointed one of the king\'s itinerant preachers in Lancashire, and after living for a time in Garstang, he was selected by the Lady Margaret Hoghton as vicar of Preston. He associated himself with Presbyterianism, and was on the celebrated committee for the ejection of \"scandalous and ignorant ministers and schoolmasters\" during the Commonwealth.
So long as Ambrose continued at Preston he was favoured with the warm friendship of the Hoghton family, their ancestral woods and the tower near Blackburn affording him sequestered places for those devout meditations and \"experiences\" that give such a charm to his diary, portions of which are quoted in his *Prima Media & Ultima* (1650, 1659). The immense auditory of his sermon (*Redeeming the Time*) at the funeral of Lady Hoghton was long a living tradition all over the county. On account of the feeling engendered by the civil war Ambrose left his great church of Preston in 1654, and became minister of Garstang, whence, however, in 1662 he was ejected along two thousand ministers who refused to conform (see Great Ejection). His after years were passed among old friends and in quiet meditation at Preston. He died of apoplexy about 20 January 1664.
## Character assessment {#character_assessment}
As a religious writer Ambrose has a vividness and freshness of imagination possessed by scarcely any of the Puritan Nonconformists. Many who have no love for Puritan doctrine, nor sympathy with Puritan experience, have appreciated the pathos and beauty of his writings, and his *Looking unto Jesus* long held its own in popular appreciation with the writings of John Bunyan.
Dr Edmund Calamy the Elder (1600--1666) wrote about him:
In the opinion of John Eglington Bailey (his biographer in the DNB), his character has been misrepresented by Wood. He was of a peaceful disposition; and though he put his name to the fierce \"Harmonious Consent\", he was not naturally a partisan. He evaded the political controversies of the time. His gentleness of character and earnest presentation of the gospel attached him to his people. He was much given to secluding himself, retiring every May into the woods of Hoghton Tower and remaining there a month.
Bailey continues that Dr. Halley justly characterises him as the most meditative puritan of Lancashire. This quality pervades his writings, which abound, besides, in deep feeling and earnest piety. Mr. Hunter has called attention to his recommendation of diaries as a means of advancing personal piety, and has remarked, in reference to the fragments from Ambrose\'s diary quoted in the \"Media\", that \"with such passages before us we cannot but lament that the carelessness of later times should have suffered such a curious and valuable document to perish; for perished it is to be feared it has\".
## Works
- *[Looking unto Jesus: A View of the Everlasting Gospel; Or, The Soul\'s Eying of Jesus as Carrying on the Great Work of Man\'s Salvation, from First to Last](https://books.google.com/books?id=Oj9aAAAAYAAJ&pg=PR3)*
- *[The Christian Warrior: Wrestling with Sin, Satan, The World and the Flesh](http://www.digitalpuritan.net/Digital%20Puritan%20Resources/Ambrose,%20Isaac/The%20Christian%20Warrior.pdf)*
- *[The well-ordered family : wherein the duties of `{{sic|i|t's|hide=y|reason=correct for the day}}`{=mediawiki} various members are described and urged. A small, but very comprehensive piece, suitable to be in the hand of every `{{sic|housho|lder|hide=y}}`{=mediawiki}; and may be especially seasonable in the present day](https://archive.org/details/wellorderedfamil00ambr/page/n5/mode/2up)*
- \'\'[Prima, media et ultima, or, The First, Middle and Last Things](https://archive
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# International Convention for the Regulation of Whaling
The **International Convention for the Regulation of Whaling** is an international environmental agreement aimed at the \"proper conservation of whale stocks and thus make possible the orderly development of the whaling industry\". It governs the commercial, scientific, and aboriginal subsistence whaling practices of 88 member states.
The convention is a successor to the 1931 Geneva Convention for Regulation of Whaling and the 1937 International Agreement for the Regulation of Whaling, established in response to the overexploitation of whales in the post-World War I period. Neither instrument was effective, but each provided the framework for the International Convention for the Regulation of Whaling, which was spearheaded by the United States and signed by 15 countries in Washington, D.C., on 3 December 1946; the convention took effect on 10 November 1948. A protocol broadening the scope of the convention\'s enforcement was signed on 19 November 1956.
The objectives of the International Convention for the Regulation of Whaling are to protect all whale species from overhunting; establish a system of international regulation for whale fisheries to ensure proper conservation and development of whale stocks; and safeguard for future generations the important natural resources represented by whale stocks. The primary instrument implementing these aims is the International Whaling Commission, established by the convention as its main decision-making body. The IWC meets annually and adopts a binding \"schedule\" that regulates catch limits, whaling methods, protected areas, and the right to carry out scientific research involving the killing of whales.
## Members
As of January 2021, there are 88 parties to the convention. The initial signatories were Argentina, Australia, Brazil, Canada, Chile, Denmark, France, the Netherlands, New Zealand, Norway, Peru, South Africa, the Soviet Union, the United Kingdom and the United States.
Although Norway is party to the convention, it maintains an objection to the 1986 IWC global moratorium and it does not apply to it.
### Withdrawals
Ten states have withdrawn from the convention since its ratification: Canada, Egypt, Greece, Guatemala, Jamaica, Japan, Mauritius, the Philippines, Seychelles and Venezuela.
Belize, Brazil, Dominica, Ecuador, Iceland, New Zealand, Norway, Panama, Solomon Islands, Sweden and Uruguay withdrew from the convention temporarily but joined again; the Netherlands withdrew twice, only to join a third time.
Japan is the most recent member to withdraw, effective June 2019, so as to resume commercial whaling.
## Effectiveness
There have been consistent disagreement over the scope of the convention. The 1946 Convention does not define a \'whale\'. Some members of IWC claim that it has the legal competence to regulate catches of only great whales (the baleen whales and the sperm whale). Others believe that all cetaceans, including the smaller dolphins and porpoises, fall within IWC jurisdiction.
An analysis by the Carnegie Council determined that while the International Convention for the Regulation of Whaling has had \"ambiguous success\" owing to its internal divisions, it has nonetheless \"successfully managed the historical transition from open whale hunting to highly restricted hunting. It has stopped all but the most highly motivated whale-hunting countries. This success has made its life more difficult, since it has left the hardest part of the problem for last
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# Irish traditional music session
**Irish traditional music sessions** are mostly informal gatherings at which people play Irish traditional music. The Irish language word for \"session\" is *seisiún*. This article discusses tune-playing, although \"session\" can also refer to a singing session or a mixed session (tunes and songs).
Barry Foy\'s *Field Guide to the Irish Music Session* defines a session as:
> \...a gathering of Irish traditional musicians for the purpose of celebrating their common interest in the music by playing it together in a relaxed, informal setting, while in the process generally beefing up the mystical cultural mantra that hums along uninterruptedly beneath all manifestations of Irishness worldwide.
## History
Before the 1940s, Irish traditional music (both in Ireland and the diaspora) was typically played in private homes and farmyards and occasionally at dance halls. In Ireland, the UK, and Canada most public houses (\"pubs\") and taverns were not legally allowed to host music in the early 20th Century. This division between folk music at home and popular commercial music in bars held on to some in Eastern Canada, where the name \"kitchen party\" denotes a gathering of folk musicians.
In the post-war era, social dancing developed in new trends based on jazz and later rock and roll, which displaced traditional music from dance halls (a similar trend happened to Central European \"polka music\" in North America). The session as understood today was purportedly invented in 1946 at the Devonshire Arms pub in Kentish Town, London, UK by a group of Irish emigrants from the Irish west coast, particularly near the town of Tubbercurry.
## Social and cultural aspects {#social_and_cultural_aspects}
The general session scheme is that someone starts a tune, and those who know it join in. Good session etiquette requires not playing if one does not know the tune (or at least quietly playing an accompaniment part) and waiting until a tune one knows comes along. In an \"open\" session, anyone who is able to play Irish music is welcome. Most often there are more-or-less recognized session leaders; sometimes there are no leaders. At times a song will be sung or a slow air played by a single musician between sets.
## Locations and times {#locations_and_times}
Sessions are usually held in public houses or taverns. A pub owner might have one or two musicians paid to come regularly in order for the session to have a base. These musicians can perform during any gaps during the day or evening when no other performers are there and wish to play. Sunday afternoons and weekday nights (especially Tuesday and Wednesday) are common times for sessions to be scheduled, on the theory that these are the least likely times for dances and concerts to be held, and therefore the times that professional musicians will be most able to show up.
Sessions can be held in homes or at various public places in addition to pubs; often at a festival sessions will be got together in the beer tent or in the vendor\'s booth of a music-loving craftsperson or dealer. When a particularly large musical event \"takes over\" an entire village, spontaneous sessions may erupt on the street corners. Sessions may also take place occasionally at wakes. House sessions are not as common now as they were in the past. In her book *Peig*, Peig Sayers notes that when she was young they often attended sessions at people\'s houses, in a practice called \'bothántiocht\'
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# Ionic bonding
**Ionic bonding** is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, or between two atoms with sharply different electronegativities, and is the primary interaction occurring in ionic compounds. It is one of the main types of bonding, along with covalent bonding and metallic bonding. Ions are atoms (or groups of atoms) with an electrostatic charge. Atoms that gain electrons make negatively charged ions (called anions). Atoms that lose electrons make positively charged ions (called cations). This transfer of electrons is known as **electrovalence** in contrast to covalence. In the simplest case, the cation is a metal atom and the anion is a nonmetal atom, but these ions can be more complex, e.g. polyatomic ions like `{{chem|NH|4|+}}`{=mediawiki} or `{{chem|SO|4|2−}}`{=mediawiki}. In simpler words, an ionic bond results from the transfer of electrons from a metal to a non-metal to obtain a full valence shell for both atoms.
*Clean* ionic bonding --- in which one atom or molecule completely transfers an electron to another --- cannot exist: all ionic compounds have some degree of covalent bonding or electron sharing. Thus, the term \"ionic bonding\" is given when the ionic character is greater than the covalent character -- that is, a bond in which there is a large difference in electronegativity between the cation and anion, causing the bonding to be more polar (ionic) than in covalent bonding where electrons are shared more equally. Bonds with partially ionic and partially covalent characters are called polar covalent bonds.
Ionic compounds conduct electricity when molten or in solution, typically not when solid. Ionic compounds generally have a high melting point, depending on the charge of the ions they consist of. The higher the charges the stronger the cohesive forces and the higher the melting point. They also tend to be soluble in water; the stronger the cohesive forces, the lower the solubility.
## Overview
Atoms that have an almost full or almost empty valence shell tend to be very reactive. Strongly electronegative atoms (such as halogens) often have only one or two empty electron states in their valence shell, and frequently bond with other atoms or gain electrons to form anions. Weakly electronegative atoms (such as alkali metals) have relatively few valence electrons, which can easily be lost to strongly electronegative atoms. As a result, weakly electronegative atoms tend to distort their electron cloud and form cations.
### Properties of ionic bonds {#properties_of_ionic_bonds}
- They are considered to be among the **strongest** of all types of chemical bonds. This often causes ionic compounds to be very stable.
- Ionic bonds have **high bond energy**. Bond energy is the mean amount of energy required to break the bond in the gaseous state.
- Most ionic compounds exist in the form of a **crystal structure**, in which the ions occupy the corners of the crystal. Such a structure is called a crystal lattice.
- Ionic compounds **lose their crystal lattice structure** and break up into ions when dissolved in water or any other polar solvent. This process is called solvation. The presence of these free ions makes aqueous ionic compound solutions good conductors of electricity. The same occurs when the compounds are heated above their melting point in a process known as melting.
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# Ionic bonding
## Formation
Ionic bonding can result from a redox reaction when atoms of an element (usually metal), whose ionization energy is low, give some of their electrons to achieve a stable electron configuration. In doing so, cations are formed. An atom of another element (usually nonmetal) with greater electron affinity accepts one or more electrons to attain a stable electron configuration, and after accepting electrons an atom becomes an anion. Typically, the stable electron configuration is one of the noble gases for elements in the s-block and the p-block, and particular stable electron configurations for d-block and f-block elements. The electrostatic attraction between the anions and cations leads to the formation of a solid with a crystallographic lattice in which the ions are stacked in an alternating fashion. In such a lattice, it is usually not possible to distinguish discrete molecular units, so that the compounds formed are not molecular. However, the ions themselves can be complex and form molecular ions like the acetate anion or the ammonium cation. For example, common table salt is sodium chloride. When sodium (Na) and chlorine (Cl) are combined, the sodium atoms each lose an electron, forming cations (Na^+^), and the chlorine atoms each gain an electron to form anions (Cl^−^). These ions are then attracted to each other in a 1:1 ratio to form sodium chloride (NaCl).
: Na + Cl → Na^+^ + Cl^−^ → NaCl
However, to maintain charge neutrality, strict ratios between anions and cations are observed so that ionic compounds, in general, obey the rules of stoichiometry despite not being molecular compounds. For compounds that are transitional to the alloys and possess mixed ionic and metallic bonding, this may not be the case anymore. Many sulfides, e.g., do form non-stoichiometric compounds.
Many ionic compounds are referred to as **salts** as they can also be formed by the neutralization reaction of an Arrhenius base like NaOH with an Arrhenius acid like HCl
: NaOH + HCl → NaCl + H~2~O
The salt NaCl is then said to consist of the acid rest Cl^−^ and the base rest Na^+^.
The removal of electrons to form the cation is endothermic, raising the system\'s overall energy. There may also be energy changes associated with breaking of existing bonds or the addition of more than one electron to form anions. However, the action of the anion\'s accepting the cation\'s valence electrons and the subsequent attraction of the ions to each other releases (lattice) energy and, thus, lowers the overall energy of the system.
Ionic bonding will occur only if the overall energy change for the reaction is favorable. In general, the reaction is exothermic, but, e.g., the formation of mercuric oxide (HgO) is endothermic. The charge of the resulting ions is a major factor in the strength of ionic bonding, e.g. a salt C^+^A^−^ is held together by electrostatic forces roughly four times weaker than C^2+^A^2−^ according to Coulomb\'s law, where C and A represent a generic cation and anion respectively. The sizes of the ions and the particular packing of the lattice are ignored in this rather simplistic argument.
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# Ionic bonding
## Structures
Ionic compounds in the solid state form lattice structures. The two principal factors in determining the form of the lattice are the relative charges of the ions and their relative sizes. Some structures are adopted by a number of compounds; for example, the structure of the rock salt sodium chloride is also adopted by many alkali halides, and binary oxides such as magnesium oxide. Pauling\'s rules provide guidelines for predicting and rationalizing the crystal structures of ionic crystals
## Strength of the bonding {#strength_of_the_bonding}
For a solid crystalline ionic compound the enthalpy change in forming the solid from gaseous ions is termed the lattice energy. The experimental value for the lattice energy can be determined using the Born--Haber cycle. It can also be calculated (predicted) using the Born--Landé equation as the sum of the electrostatic potential energy, calculated by summing interactions between cations and anions, and a short-range repulsive potential energy term. The electrostatic potential can be expressed in terms of the interionic separation and a constant (Madelung constant) that takes account of the geometry of the crystal. The further away from the nucleus the weaker the shield. The Born--Landé equation gives a reasonable fit to the lattice energy of, e.g., sodium chloride, where the calculated (predicted) value is −756 kJ/mol, which compares to −787 kJ/mol using the Born--Haber cycle. In aqueous solution the binding strength can be described by the Bjerrum or Fuoss equation as function of the ion charges, rather independent of the nature of the ions such as polarizability or size. The strength of salt bridges is most often evaluated by measurements of equilibria between molecules containing cationic and anionic sites, most often in solution. Equilibrium constants in water indicate additive free energy contributions for each salt bridge. Another method for the identification of hydrogen bonds in complicated molecules is crystallography, sometimes also NMR-spectroscopy.
The attractive forces defining the strength of ionic bonding can be modeled by Coulomb\'s Law. Ionic bond strengths are typically (cited ranges vary) between 170 and 1500 kJ/mol.
## Polarization power effects {#polarization_power_effects}
Ions in crystal lattices of purely ionic compounds are spherical; however, if the positive ion is small and/or highly charged, it will distort the electron cloud of the negative ion, an effect summarised in Fajans\' rules. This polarization of the negative ion leads to a build-up of extra charge density between the two nuclei, that is, to partial covalency. Larger negative ions are more easily polarized, but the effect is usually important only when positive ions with charges of 3+ (e.g., Al^3+^) are involved. However, 2+ ions (Be^2+^) or even 1+ (Li^+^) show some polarizing power because their sizes are so small (e.g., LiI is ionic but has some covalent bonding present). Note that this is not the ionic polarization effect that refers to the displacement of ions in the lattice due to the application of an electric field.
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# Ionic bonding
## Comparison with covalent bonding {#comparison_with_covalent_bonding}
In ionic bonding, the atoms are bound by the attraction of oppositely charged ions, whereas, in covalent bonding, atoms are bound by sharing electrons to attain stable electron configurations. In covalent bonding, the molecular geometry around each atom is determined by valence shell electron pair repulsion VSEPR rules, whereas, in ionic materials, the geometry follows maximum packing rules. One could say that covalent bonding is more *directional* in the sense that the energy penalty for not adhering to the optimum bond angles is large, whereas ionic bonding has no such penalty. There are no shared electron pairs to repel each other, the ions should simply be packed as efficiently as possible. This often leads to much higher coordination numbers. In NaCl, each ion has 6 bonds and all bond angles are 90°. In CsCl the coordination number is 8. By comparison, carbon typically has a maximum of four bonds.
Purely ionic bonding cannot exist, as the proximity of the entities involved in the bonding allows some degree of sharing electron density between them. Therefore, all ionic bonding has some covalent character. Thus, bonding is considered ionic where the ionic character is greater than the covalent character. The larger the difference in electronegativity between the two types of atoms involved in the bonding, the more ionic (polar) it is. Bonds with partially ionic and partially covalent character are called polar covalent bonds. For example, Na--Cl and Mg--O interactions have a few percent covalency, while Si--O bonds are usually \~50% ionic and \~50% covalent. Pauling estimated that an electronegativity difference of 1.7 (on the Pauling scale) corresponds to 50% ionic character, so that a difference greater than 1.7 corresponds to a bond which is predominantly ionic.
Ionic character in covalent bonds can be directly measured for atoms having quadrupolar nuclei (^2^H, ^14^N, ^81,79^Br, ^35,37^Cl or ^127^I). These nuclei are generally objects of NQR nuclear quadrupole resonance and NMR nuclear magnetic resonance studies. Interactions between the nuclear quadrupole moments *Q* and the electric field gradients (EFG) are characterized via the nuclear quadrupole coupling constants
: QCC = `{{sfrac|''e''<sup>2</sup>''q''<sub>zz</sub>''Q''|''h''}}`{=mediawiki}
where the *eq*~zz~ term corresponds to the principal component of the EFG tensor and *e* is the elementary charge. In turn, the electric field gradient opens the way to description of bonding modes in molecules when the QCC values are accurately determined by NMR or NQR methods.
In general, when ionic bonding occurs in the solid (or liquid) state, it is not possible to talk about a single \"ionic bond\" between two individual atoms, because the cohesive forces that keep the lattice together are of a more collective nature. This is quite different in the case of covalent bonding, where we can often speak of a distinct bond localized between two particular atoms. However, even if ionic bonding is combined with some covalency, the result is *not* necessarily discrete bonds of a localized character. In such cases, the resulting bonding often requires description in terms of a band structure consisting of gigantic molecular orbitals spanning the entire crystal. Thus, the bonding in the solid often retains its collective rather than localized nature. When the difference in electronegativity is decreased, the bonding may then lead to a semiconductor, a semimetal or eventually a metallic conductor with metallic bonding
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# Identity element
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# Industrial archaeology of Dartmoor
The **industrial archaeology of Dartmoor** covers a number of the industries which have, over the ages, taken place on Dartmoor, and the remaining evidence surrounding them. Currently only three industries are economically significant, yet all three will inevitably leave their own traces on the moor: china clay mining, farming and tourism.
A good general guide to the commercial activities on Dartmoor at the end of the 19th century is William Crossing\'s *The Dartmoor Worker*.
## Mining
In former times, lead, silver, tin and copper were mined extensively on Dartmoor. The most obvious evidence of mining to the casual visitor to Dartmoor are the remains of the old engine-house at Wheal Betsy which is alongside the A386 road between Tavistock and Okehampton. The word *Wheal* has a particular meaning in Devon and Cornwall being either a tin or a copper mine, however in the case of Wheal Betsy it was principally lead and silver which were mined.
Once widely practised by many miners across the moor, by the early 1900s only a few tinners remained, and mining had almost completely ceased twenty years later. Some of the more significant mines were Eylesbarrow, Knock Mine, Vitifer Mine and Hexworthy Mine. The last active mine in the Dartmoor area was Great Rock Mine, which shut down in 1969.
## Quarrying
Dartmoor granite has been used in many Devon and Cornish buildings. The prison at Princetown was built from granite taken from Walkhampton Common. When the horse tramroad from Plymouth to Princetown was completed in 1823, large quantities of granite were more easily transported.
There were three major granite quarries on the moor: Haytor, Foggintor and Merrivale. The granite quarries around Haytor were the source of the stone used in several famous structures, including the New London Bridge, completed in 1831. This granite was transported from the moor via the Haytor Granite Tramway, stretches of which are still visible.
The extensive quarries at Foggintor provided granite for the construction of London\'s Nelson\'s Column in the early 1840s, and New Scotland Yard was faced with granite from the quarry at Merrivale. Merrivale Quarry continued excavating and working its own granite until the 1970s, producing gravestones and agricultural rollers. Work at Merrivale continued until the 1990s, for the last 20 years imported stone such as gabbro from Norway and Italian marble was dressed and polished. The unusual pink granite at Great Trowlesworthy Tor was also quarried, and there were many other small granite quarries dotted around the moor. Various metamorphic rocks were also quarried in the metamorphic aureole around the edge of the moor, most notably at Meldon.
## Gunpowder factory {#gunpowder_factory}
In 1844 a factory for making gunpowder was built on the open moor, not far from Postbridge. Gunpowder was needed for the tin mines and granite quarries then in operation on the moor. The buildings were widely spaced from one another for safety and the mechanical power for grinding (\"incorporating\") the powder was derived from waterwheels driven by a leat.
Now known as \"Powdermills\" or \"Powder Mills\", there are extensive remains of this factory still visible. Two chimneys still stand and the walls of the two sturdily-built incorporating mills with central waterwheels survive well: they were built with substantial walls but flimsy roofs so that in the event of an explosion, the force of the blast would be directed safely upwards. The ruins of a number of ancillary buildings also survive. A proving mortar---a type of small cannon used to gauge the strength of the gunpowder---used by the factory still lies by the side of the road to the nearby pottery.
## Peat-cutting {#peat_cutting}
Peat-cutting for fuel occurred at some locations on Dartmoor until certainly the 1970s, usually for personal use. The right of Dartmoor commoners to cut peat for fuel is known as *turbary*. These rights were conferred a long time ago, pre-dating most written records. The area once known as the *Turbary of Alberysheved* between the River Teign and the headwaters of the River Bovey is mentioned in the Perambulation of the Forest of Dartmoor of 1240 (by 1609 the name of the area had changed to Turf Hill).
An attempt was made to commercialise the cutting of peat in 1901 at Rattle Brook Head, however this quickly failed.
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# Industrial archaeology of Dartmoor
## Warrens
From at least the 13th century until early in the 20th, rabbits were kept on a commercial scale, both for their flesh and their fur. Documentary evidence for this exists in place names such as Trowlesworthy Warren (mentioned in a document dated 1272) and Warren House Inn. The physical evidence, in the form of pillow mounds is also plentiful, for example there are 50 pillow mounds at Legis Tor Warren. The sophistication of the warreners is shown by the existence of vermin traps that were placed near the warrens to capture weasels and stoats attempting to get at the rabbits.
The significance of the term *warren* nowadays is not what it once was. In the Middle Ages it was a privileged place, and the creatures of the warren were protected by the king \'for his princely delight and pleasure\'.
The subject of warrening on Dartmoor was addressed in Eden Phillpotts\' story *The River*.
## Farming
Farming has been practised on Dartmoor since time immemorial. The dry-stone walls which separate fields and mark boundaries give an idea of the extent to which the landscape has been shaped by farming. There is little or no arable farming within the moor, mostly being given over to livestock farming on account of the thin and rocky soil. Some Dartmoor farms are remote in the extreme
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# Isidore of Miletus
**Isidore of Miletus** (*Ἰσίδωρος ὁ Μιλήσιος*; Medieval Greek pronunciation: `{{IPA|el|iˈsiðoros o miˈlisios|}}`{=mediawiki}; *Isidorus Miletus*) was one of the two main Byzantine Greek mathematician, physicist and architects (Anthemius of Tralles was the other) that Emperor Justinian I commissioned to design the cathedral Hagia Sophia in Constantinople from 532 to 537. He was born c. 475 AD. The creation of an important compilation of Archimedes\' works has been attributed to him. The spurious Book XV from Euclid\'s Elements has been partly attributed to Isidore of Miletus.
## Biography
Isidore of Miletus was a renowned scientist and mathematician before Emperor Justinian I hired him. Isidorus taught stereometry and physics at the universities of Alexandria and then of Constantinople, and wrote a commentary on an older treatise on vaulting. Eutocius together with Isidore studied Archimedes\' work. Isidore is also renowned for producing the first comprehensive compilation of Archimedes\' work, the Archimedes palimpsest survived to the present.
### Teachings and writings {#teachings_and_writings}
A majority of Isidore\'s preserved work are his edits and commentaries on older Greek mathematical texts. For example, Isidore is known to have revised and checked some of Archimedes\' works and also Book XV of Euclid\'s elements.
That being said, claims from Alan Cameron have been made about a hypothetical \"School of Isidore\". Between his work on architectural exploits, Isidore taught about math and geometry of the time. The School of Isidore is supported more by the presence of his teaching\'s in much of his students (such as Eutocious) works rather than his own writings. In an edit of the fifteenth book of Euclid\'s *Elements,* for instance, the editor quotes Isidore, but then proceeds to explain that Isidore did not publish much of his work himself. Instead, he taught, and once he himself could understand the material, did not see a need to write it down. It is because of this that Cameron claims that Isidore helped to revitalize interest in ancient mathematicians in Constantinople and Alexandria circa 510.
In addition to editing the works of others, Isidore is known to have written his own commentary on Hero of Alexandria\'s \"On Vaulting\", which discussed aspects of vault construction and design in relation to geometry. While this commentary is lost Eutocius makes mention of it in his own writings. It is when referring to this work that Eutocius credits Isidore with designing a special compass for the purpose of drawing parabolas. Isidore\'s invention allowed for the drawing of parabolas with a greater level accuracy than that of which many previous methods were capable. From Eutocius (or his copyist) it is believed that one notable use for Isidores invention was to visually solve the problem of doubling the volume of a cube. This was said to be done by drawing two parabolas and finding the point where they intersect. In addition to their mathematical applications, Isidore is believed to have highlighted the uses of applying the use of parabolas to the construction of vaults.
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# Isidore of Miletus
## Biography
### Hagia Sophia {#hagia_sophia}
Emperor Justinian I appointed his architects to rebuild the Hagia Sophia following his victory over protesters within the capital city of the Roman Empire, Constantinople. The first basilica was completed in 360 and remodelled from 404 to 415, but had been damaged in 532 in the course of the Nika Riot, "The temple of Sophia, the baths of Zeuxippus, and the imperial courtyard from the Propylaia all the way to the so-called House of Ares were burned up and destroyed, as were both of the great porticoes that lead to the forum that is named after Constantine, houses of prosperous people, and a great deal of other properties."
The rival factions of Constantinople populace, the Blues and the Greens, opposed each other in the chariot races at the Hippodrome and often resorted to violence. During the Nika Riot, more than thirty thousand people were killed. Emperor Justinian I ensured that his new structure would not be burned down, like its predecessors, by commissioning architects that would build the church mainly out of stone, rather than wood, "He compacted it of baked brick and mortar, and in many places bound it together with iron, but made no use of wood, so that the church should no longer prove combustible." The construction of the Hagia Sophia began so fast after the riots were quelled that many think that Justinian had his architects begin planning it before the riots even stopped.
Isidore of Miletus and Anthemius of Tralles originally planned on a main hall of the Hagia Sophia that measured 70 by 75 metres (230 x 250 ft), making it the largest church in Constantinople, but the original dome was nearly 6 metres (20 ft) lower than it was constructed, "Justinian suppressed these riots and took the opportunity of marking his victory by erecting in 532-7 the new Hagia Sophia, one of the largest, most lavish, and most expensive buildings of all time."
Although Isidore of Miletus and Anthemius of Tralles were not formally educated in architecture, they were scientists who could organize the logistics of drawing thousands of labourers and unprecedented loads of rare raw materials from around the Roman Empire to construct the Hagia Sophia for Emperor Justinian I. Isidore and Anthemius obtained stone from as far away as Egypt, Syria, and Libya, and columns from several temples in Rome. The finished product was built in admirable form for the Roman Emperor, "All of these elements marvellously fitted together in mid-air, suspended from one another and reposing only on the parts adjacent to them, produce a unified and most remarkable harmony in the work, and yet do not allow the spectators to rest their gaze upon any one of them for a length of time." It is believed that Isidore did much of the work on the domes of the Hagia Sophia due to his extensive work on vaults, and his commentary, \"On Vaulting\".
The Hagia Sophia architects innovatively combined the longitudinal structure of a Roman basilica and the central plan of a drum-supported dome, in order to withstand the high magnitude earthquakes of the Marmara Region, "However, in May 558, little more than 20 years after the Church's dedication, following the earthquakes of August 553 and December 557, parts of the central dome and its supporting structure system collapsed." The Hagia Sophia was repeatedly cracked by earthquakes and was quickly repaired. Isidore of Miletus' nephew, Isidore the Younger, introduced the new dome design that can be viewed in the Hagia Sophia in present-day Istanbul, Turkey. Originally the dome was constructed without ribs, but achieved its present-day construction with ribs when Isidore the Younger repaired the church.
After a great earthquake in 989 ruined the dome of Hagia Sophia, the Byzantine officials summoned Trdat the Architect to Byzantium to organize repairs. The restored dome was completed by 994
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# International African Institute
The **International African Institute** (**IAI**) was founded (as the **International Institute of African Languages and Cultures** - **IIALC**) in 1926 in London for the study of African languages. Frederick Lugard was the first chairman (1926 to his death in 1945); Diedrich Hermann Westermann (1926 to 1939) and Maurice Delafosse (1926) were the initial co-directors.
Since 1928, the IAI has published a quarterly journal, *Africa*. For some years during the 1950s and 1960s, the assistant editor was the novelist Barbara Pym.
The IAI\'s mission is \"to promote the education of the public in the study of Africa and its languages and cultures\". Its operations includes seminars, journals, monographs, edited volumes and stimulating scholarship within Africa.
## Publications
The IAI has been involved in scholarly publishing since 1927. Scholars whose work has been published by the institute include Emmanuel K. Akyeampong, Samir Amin, Karin Barber, Alex de Waal, Patrick Chabal, Mary Douglas, E. E. Evans-Pritchard, Jack Goody, Jane Guyer, Monica Hunter, Bronislaw Malinowski, Z. K. Matthews, D. A. Masolo, Achille Mbembe, Thomas Mofolo, John Middleton, Simon Ottenberg, J. D. Y. Peel, Mamphela Ramphele, Isaac Schapera, Monica Wilson and V. Y. Mudimbe.
IAI publications fall into a number of series, notably **International African Library** and **International African Seminars**. The International African Library is published from volume 41 (2011) by Cambridge University Press; Volumes 7--40 are available from Edinburgh University Press. `{{as of|November 2016}}`{=mediawiki}, there are 49 volumes.
## Archives
The archives of the International African Institute are held at the [Archives Division](http://www.lse.ac.uk/library/archive/Default.htm) of the Library of the London School of Economics. An [online catalogue](http://archives.lse.ac.uk/TreeBrowse.aspx?src=CalmView.Catalog&field=RefNo&key=IAI) of these papers is available.
## History
### Africa alphabet {#africa_alphabet}
In 1928, the IAI (then IIALC) published an \"Africa Alphabet\" to facilitate standardization of Latin-based writing systems for African languages.
### Prize for African-language literature, 1929--50 {#prize_for_african_language_literature_192950}
From April 1929 to 1950, the IAI offered prizes for works of literature in African languages
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# Idiot
`{{pp-semi-vandalism|small=yes}}`{=mediawiki}
An **idiot**, in modern use, is a stupid or foolish person.
\"Idiot\" was formerly a technical term in legal and psychiatric contexts for some kinds of profound intellectual disability where the mental age is two years or less, and the person cannot guard themself against common physical dangers. The term was gradually replaced by \"profound mental retardation\", which has since been replaced by other terms. Along with terms like moron, imbecile, retard and cretin, its use to describe people with mental disabilities is considered archaic and offensive. Moral idiocy refers to a moral disability.
## Etymology
The word \"idiot\" ultimately comes from the Greek noun *ἰδιώτης\]\]* *idiōtēs* \'a private person, individual\' (as opposed to the state), \'a private citizen\' (as opposed to someone with a political office), \'a common man\', \'a person lacking professional skill, layman\', later \'unskilled\', \'ignorant\', derived from the adjective *ἴδιος* *idios* \'personal\' (not public, not shared). In Latin, *idiota* was borrowed in the meaning \'uneducated\', \'ignorant\', \'common\', and in Late Latin came to mean \'crude, illiterate, ignorant\'. In French, it kept the meaning of \'illiterate\', \'ignorant\', and added the meaning \'stupid\' in the 13th century. In English, it added the meaning \'mentally deficient\' in the 14th century.
Many political commentators, starting as early as 1856, have interpreted the word \"idiot\" as reflecting the Ancient Athenians\' attitudes to civic participation and private life, combining the ancient meaning of \'private citizen\' with the modern meaning \'fool\' to conclude that the Greeks used the word to say that it is selfish and foolish not to participate in public life. But this is not how the Greeks used the word.
It is certainly true that the Greeks valued civic participation and criticized non-participation. Thucydides quotes Pericles\' Funeral Oration as saying: \"\[we\] regard\... him who takes no part in these \[public\] duties not as unambitious but as useless\" (*τόν τε μηδὲν τῶνδε μετέχοντα οὐκ ἀπράγμονα, ἀλλ᾽ ἀχρεῖον νομίζομεν*). However, neither he nor any other ancient author uses the word \"idiot\" to describe non-participants, or in a derogatory sense; its most common use was simply a private citizen or amateur as opposed to a government official, professional, or expert. The derogatory sense came centuries later, and was unrelated to the political meaning.
## Disability and early classification and nomenclature {#disability_and_early_classification_and_nomenclature}
In 19th- and early 20th-century medicine and psychology, an \"idiot\" was a person with a very profound intellectual disability, being diagnosed with \"idiocy\". In the early 1900s, Dr. Henry H. Goddard proposed a classification system for intellectual disability based on the Binet-Simon concept of mental age. Individuals with the lowest mental age level (less than three years) were identified as *idiots*; *imbeciles* had a mental age of three to seven years, and *morons* had a mental age of seven to ten years. The term \"idiot\" was used to refer to people having an IQ below 30 IQ, or intelligence quotient, was originally determined by dividing a person\'s mental age, as determined by standardized tests, by their actual age. The concept of mental age has fallen into disfavor, though, and IQ is now determined on the basis of statistical distributions.
In the obsolete medical classification (ICD-9, 1977), these people were said to have \"profound mental retardation\" or \"profound mental subnormality\" with IQ under 20.
## Regional law {#regional_law}
### United States {#united_states}
Until 2007, the California Penal Code Section 26 stated that \"Idiots\" were one of six types of people who are not capable of committing crimes. In 2007 the code was amended to read \"persons who are mentally incapacitated.\" In 2008, Iowa voters passed a measure replacing \"idiot, or insane person\" in the State\'s constitution with \"person adjudged mentally incompetent.\"
In the constitution of several U.S. states, \"idiots\" do not have the right to vote:
- Kentucky Section 145
- Mississippi Article 12, Section 241
- Ohio Article V, Section 6
The constitution of the state of Arkansas was amended in the general election of 2008 to, among other things, repeal a provision (Article 3, Section 5) which had until its repeal prohibited \"idiots or insane persons\" from voting.
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# Idiot
## In literature {#in_literature}
A few authors have used \"idiot\" characters in novels, plays and poetry. Often these characters are used to highlight or indicate something else (allegory). Examples of such usage are William Faulkner\'s *The Sound and the Fury*, Daphne du Maurier\'s *Rebecca* and William Wordsworth\'s *The Idiot Boy*. Idiot characters in literature are often confused with or subsumed within mad or lunatic characters. The most common intersection between these two categories of mental impairment occurs in the polemic surrounding Edmund from William Shakespeare\'s *King Lear*.
In Fyodor Dostoevsky\'s novel *The Idiot* the title refers to the central character Prince Myshkin, a man whose innocence, kindness and humility, combined with his occasional epileptic symptoms, cause many in the corrupt, egoistic culture around him to mistakenly assume that he lacks intelligence. In *The Antichrist*, Nietzsche applies the word \"idiot\" to Jesus in a comparable fashion, almost certainly in an allusion to Dostoevsky\'s use of the word: \"One has to regret that no Dostoevsky lived in the neighbourhood of this most interesting *décadent*; I mean someone who could feel the thrilling fascination of such a combination of the sublime, the sick and the childish
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# Instructional theory
An **instructional theory** is \"a theory that offers explicit guidance on how to better help people learn and develop.\" It provides insights about what is likely to happen and why with respect to different kinds of teaching and learning activities while helping indicate approaches for their evaluation. Instructional designers focus on how to best structure material and instructional behavior to facilitate learning.
## Development
Originating in the United States in the late 1970s, *instructional theory* is influenced by three basic theories in educational thought: behaviorism, the theory that helps us understand how people conform to predetermined standards; cognitivism, the theory that learning occurs through mental associations; and constructivism, the theory explores the value of human activity as a critical function of gaining knowledge. Instructional theory is heavily influenced by the 1956 work of Benjamin Bloom, a University of Chicago professor, and the results of his Taxonomy of Education Objectives---one of the first modern codifications of the learning process. One of the first instructional theorists was Robert M. Gagne, who in 1965 published *Conditions of Learning* for the Florida State University\'s Department of Educational Research.
## Definition
Instructional theory is different than learning theory. A learning theory *describes* how learning takes place, and an instructional theory *prescribes* how to better help people learn. Learning theories often inform instructional theory, and three general theoretical stances take part in this influence: behaviorism (learning as response acquisition), cognitivism (learning as knowledge acquisition), and constructivism (learning as knowledge construction). Instructional theory helps us create conditions that increases the probability of learning. Its goal is understanding the instructional system and to improve the process of instruction.
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# Instructional theory
## Overview
Instructional theories identify what instruction or teaching should be like. It outlines strategies that an educator may adopt to achieve the learning objectives. Instructional theories are adapted based on the educational content and more importantly the learning style of the students. They are used as teaching guidelines/tools by teachers/trainers to facilitate learning. Instructional theories encompass different instructional methods, models and strategies.
David Merrill\'s First Principles of Instruction discusses universal methods of instruction, situational methods and core ideas of the post-industrial paradigm of instruction.
**Universal Methods of Instruction:**
- Task-Centered Principle - instruction should use a progression of increasingly complex whole tasks.
- Demonstration Principle - instruction should guide learners through a skill and engage peer discussion/demonstration.
- Application Principle - instruction should provide intrinsic or corrective feedback and engage peer-collaboration.
- Activation Principle - instruction should build upon prior knowledge and encourage learners to acquire a structure for organizing new knowledge.
- Integration Principle - instruction should engage learners in peer-critiques and synthesizing newly acquired knowledge.
**Situational Methods:**
based on different approaches to instruction
- Role play
- Synectics
- Mastery learning
- Direct instruction
- Discussion
- Conflict resolution
- Peer learning
- Experiential learning
- Problem-based learning
- Simulation-based learning
based on different learning outcomes:
- Knowledge
- Comprehension
- Application
- Analysis
- Synthesis
- Evaluation
- Affective development
- Integrated learning
**Core ideas for the Post-industrial Paradigm of Instruction:**
- Learner centered vs. teacher centered instruction -- with respect to the focus, instruction can be based on the capability and style of the learner or the teacher.
- Learning by doing vs. teacher presenting -- Students often learn more by doing rather than simply listening to instructions given by the teacher.
- Attainment based vs. time based progress -- The instruction can either be based on the focus on the mastery of the concept or the time spent on learning the concept.
- Customized vs. standardized instruction -- The instruction can be different for different learners or the instruction can be given in general to the entire classroom
- Criterion referenced vs. norm referenced instruction -- Instruction related to different types of evaluations.
- Collaborative vs. individual instruction -- Instruction can be for a team of students or individual students.
- Enjoyable vs. unpleasant instructions -- Instructions can create a pleasant learning experience or a negative one (often to enforce discipline). Teachers must take care to ensure positive experiences.
Four tasks of Instructional theory:
- Knowledge selection
- Knowledge sequence
- Interaction management
- Setting of interaction environment
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# Instructional theory
## Critiques
Paulo Freire\'s work appears to critique instructional approaches that adhere to the knowledge acquisition stance, and his work *Pedagogy of the Oppressed* has had a broad influence over a generation of American educators with his critique of various \"banking\" models of education and analysis of the teacher-student relationship.
Freire explains, \"Narration (with the teacher as narrator) leads the students to memorize mechanically the narrated content. Worse yet, it turns them into \"containers\", into \"receptacles\" to be \"filled\" by the teacher. The more completely she fills the receptacles, the better a teacher she is. The more meekly the receptacles permit themselves to be filled, the better students they are.\" In this way he explains educator creates an act of depositing knowledge in a student. The student thus becomes a repository of knowledge. Freire explains that this system that diminishes creativity and knowledge suffers. Knowledge, according to Freire, comes about only through the learner by inquiry and pursuing the subjects in the world and through interpersonal interaction.
Freire further states, \"In the banking concept of education, knowledge is a gift bestowed by those who consider themselves knowledgeable upon those whom they consider to know nothing. Projecting an absolute ignorance onto others, a characteristic of the ideology of oppression, negates education and knowledge as processes of inquiry. The teacher presents himself to his students as their necessary opposite; by considering their ignorance absolute, he justifies his own existence. The students, alienated like the slave in the Hegelian dialectic, accept their ignorance as justifying the teacher\'s existence---but, unlike the slave, they never discover that they educate the teacher.\" Freire then offered an alternative stance and wrote, \"The raison d\'etre of libertarian education, on the other hand, lies in its drive towards reconciliation. Education must begin with the solution of the teacher-student contradiction, by reconciling the poles of the contradiction so that both are simultaneously teachers and students.\"
In the article, \"A process for the critical analysis of instructional theory\", the authors use an ontology-building process to review and analyze concepts across different instructional theories. Here are their findings:
- Concepts exist in theoretical writing that theorists do not address directly.
- These tacit concepts, which supply the ontological categories, enable a more detailed comparison of theories beyond specific terminologies.
- Divergences between theories can be concealed behind common terms used by different theorists.
- A false sense of understanding often arises from a cursory, uncritical reading of the theories.
- Discontinuities and gaps are revealed within the theoretical literature when the tacit concepts are elicited
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# Infusoria
**Infusoria** is a word used to describe various freshwater microorganisms, including ciliates, copepods, euglenoids, planktonic crustaceans, protozoa, unicellular algae and small invertebrates. Some authors (e.g., Bütschli) have used the term as a synonym for Ciliophora. In modern, formal classifications, the term is considered obsolete; the microorganisms previously and colloquially referred to as Infusoria are mostly assigned to the clades Diaphoretickes (e.g. ciliates, most algae), Amorphea (e.g. crustaceans and other small animals) and Discoba (euglenids).
In other contexts, the term is used to define various aquatic microorganisms found in decomposing matter.
## Aquarium use {#aquarium_use}
Certain microorganisms, including cyclops and daphnia (among others), are sold as a supplemental fish food. Some fish stores or pet shops may have these infusoria available for live purchase, but typically they are sold in frozen cubes---for example, by the Japan-based fish food brand Hikari. Still, some advanced aquarists, with especially large collections of fish, will breed and cultivate their own supplies of the microorganisms.
Infusoria are especially used by aquarists and fish breeders to feed fish fry; because of their small sizes, infusoria can be used to rear newly-hatched offspring of many common (and also less common) aquarium species. Many average home aquaria are unable to naturally supply sufficient infusoria for fish-rearing, so hobbyists may create and maintain their own cultures, either through utilizing their own existing aquarium water or by using one of the many commercial cultures available.
Infusoria can be cultured at-home by soaking any decomposing vegetative matter, such as papaya or cucumber peels, in a jar of aged (i.e., chlorine-free) water, preferably from an existing aquarium setup. The culture starts to proliferate in two to three days, depending on temperature and light received. The water first turns cloudy because of a rise in levels of bacteria, but clears up once the infusoria consume them. At this point, the infusoria are usually visible to the naked eye as small, white motile specks. They can be easily fed to fish with the use of a large turkey-baster or by gently scooping with a very fine net. Additionally, the water in which the infusoria are kept in can be changed periodically, even one to two times per week, by draining and replacing up to 50% of the volume of water (for hygienic and maintenance purposes)
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# Icosidodecahedron
In geometry, an **icosidodecahedron** or **pentagonal gyrobirotunda** is a polyhedron with twenty (*icosi-*) triangular faces and twelve (*dodeca-*) pentagonal faces. An icosidodecahedron has 30 identical vertices, with two triangles and two pentagons meeting at each, and 60 identical edges, each separating a triangle from a pentagon. As such, it is one of the Archimedean solids and more particularly, a quasiregular polyhedron.
## Construction
One way to construct the icosidodecahedron is to start with two pentagonal rotunda by attaching them to their bases. These rotundas cover their decagonal base so that the resulting polyhedron has 32 faces, 30 vertices, and 60 edges. This construction is similar to one of the Johnson solids, the pentagonal orthobirotunda. The difference is that the icosidodecahedron is constructed by twisting its rotundas by 36°, a process known as gyration, resulting in the pentagonal face connecting to the triangular one. The icosidodecahedron has an alternative name, *pentagonal gyrobirotunda*.`{{r|berman|os}}`{=mediawiki} `{{multiple image
| image1 = Icosidodecahedron.png
| image2 = Dissected icosidodecahedron.png
| image3 = Pentagonal orthobirotunda solid.png
| footer = The difference between icosidodecahedron and pentagonal orthobirotunda, and its dissection.
| align = center
| total_width = 400
}}`{=mediawiki}
There is another way to construct it, and that is rectification of an Icosahedron or a Dodecahedron.
Convenient Cartesian coordinates for the vertices of an icosidodecahedron with unit edges are given by the even permutations of: $(\pm 1, 0, 0), \qquad \tfrac{1}{2}\left(\pm \varphi, \pm \tfrac{1}{\varphi}, \pm 1 \right),$ where $\varphi$ denotes the golden ratio.`{{r|dm}}`{=mediawiki}
## Properties
The surface area of an icosidodecahedron `{{mvar|A}}`{=mediawiki} can be determined by calculating the area of all pentagonal faces. The volume of an icosidodecahedron `{{mvar|V}}`{=mediawiki} can be determined by slicing it off into two pentagonal rotunda, after which summing up their volumes. Therefore, its surface area and volume can be formulated as:`{{r|berman}}`{=mediawiki} $\begin{align}
A &= \left(5\sqrt{3}+3\sqrt{25+10\sqrt{5}}\right) a^2 &\approx 29.306a^2 \\
V &= \frac{45+17\sqrt{5}}{6}a^3 &\approx 13.836a^3.
\end{align}$
The dihedral angle of an icosidodecahedron between pentagon-to-triangle is $\arccos \left(-\sqrt{\frac{5 + 2\sqrt{5}}{15}} \right) \approx 142.62^\circ,$ determined by calculating the angle of a pentagonal rotunda.`{{r|williams}}`{=mediawiki}
An icosidodecahedron has icosahedral symmetry, and its first stellation is the compound of a dodecahedron and its dual icosahedron, with the vertices of the icosidodecahedron located at the midpoints of the edges of either.
The icosidodecahedron is an Archimedean solid, meaning it is a highly symmetric and semi-regular polyhedron, and two or more different regular polygonal faces meet in a vertex.`{{r|diudea}}`{=mediawiki} The polygonal faces that meet for every vertex are two equilateral triangles and two regular pentagons, and the vertex figure of an icosidodecahedron is $(3 \cdot 5)^2 = 3^2 \cdot 5^2$. Its dual polyhedron is rhombic triacontahedron, a Catalan solid.`{{r|williams}}`{=mediawiki}
The icosidodecahedron has 6 central decagons. Projected into a sphere, they define 6 great circles. `{{harvtxt|Fuller|1975}}`{=mediawiki} used these 6 great circles, along with 15 and 10 others in two other polyhedra to define his 31 great circles of the spherical icosahedron.`{{r|fuller}}`{=mediawiki}
The long radius (center to vertex) of the icosidodecahedron is in the golden ratio to its edge length; thus its radius is `{{mvar|φ}}`{=mediawiki} if its edge length is 1, and its edge length is `{{math|{{sfrac|1|''φ''}}}}`{=mediawiki} if its radius is 1.`{{r|williams}}`{=mediawiki} Only a few uniform polytopes have this property, including the four-dimensional 600-cell, the three-dimensional icosidodecahedron, and the two-dimensional decagon. (The icosidodecahedron is the equatorial cross-section of the 600-cell, and the decagon is the equatorial cross-section of the icosidodecahedron.) These *radially golden* polytopes can be constructed, with their radii, from golden triangles which meet at the center, each contributing two radii and an edge.
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# Icosidodecahedron
## Related polytopes {#related_polytopes}
The icosidodecahedron is a rectified dodecahedron and also a rectified icosahedron, existing as the full-edge truncation between these regular solids.
The icosidodecahedron contains 12 pentagons of the dodecahedron and 20 triangles of the icosahedron: `{{Icosahedral truncations}}`{=mediawiki}
The icosidodecahedron exists in a sequence of symmetries of quasiregular polyhedra and tilings with vertex configurations (3.*n*)^2^, progressing from tilings of the sphere to the Euclidean plane and into the hyperbolic plane. With orbifold notation symmetry of \**n*32 all of these tilings are wythoff construction within a fundamental domain of symmetry, with generator points at the right angle corner of the domain. `{{Quasiregular3 small table}}`{=mediawiki}
### Related polyhedra {#related_polyhedra}
The truncated cube can be turned into an icosidodecahedron by dividing the octagons into two pentagons and two triangles. It has pyritohedral symmetry.
Eight uniform star polyhedra share the same vertex arrangement. Of these, two also share the same edge arrangement: the small icosihemidodecahedron (having the triangular faces in common), and the small dodecahemidodecahedron (having the pentagonal faces in common). The vertex arrangement is also shared with the compounds of five octahedra and of five tetrahemihexahedra.
+:--------------------------:+:-----------------------------------:+:----------------------------:+
| \ | \ | \ |
| Icosidodecahedron | Small icosihemidodecahedron | Small dodecahemidodecahedron |
+----------------------------+-------------------------------------+------------------------------+
| \ | \ | \ |
| Great icosidodecahedron | Great dodecahemidodecahedron | Great icosihemidodecahedron |
+----------------------------+-------------------------------------+------------------------------+
| \ | \ | \ |
| Dodecadodecahedron | Small dodecahemicosahedron | Great dodecahemicosahedron |
+----------------------------+-------------------------------------+------------------------------+
| \ | \ | |
| Compound of five octahedra | Compound of five tetrahemihexahedra | |
+----------------------------+-------------------------------------+------------------------------+
### Related polychora {#related_polychora}
In four-dimensional geometry, the icosidodecahedron appears in the regular 600-cell as the equatorial slice that belongs to the vertex-first passage of the 600-cell through 3D space. In other words: the 30 vertices of the 600-cell which lie at arc distances of 90 degrees on its circumscribed hypersphere from a pair of opposite vertices, are the vertices of an icosidodecahedron. The wireframe figure of the 600-cell consists of 72 flat regular decagons. Six of these are the equatorial decagons to a pair of opposite vertices, and these six form the wireframe figure of an icosidodecahedron.
If a 600-cell is stereographically projected to 3-space about any vertex and all points are normalised, the geodesics upon which edges fall comprise the icosidodecahedron\'s barycentric subdivision.
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# Icosidodecahedron
## Graph
The skeleton of an icosidodecahedron can be represented as the symmetric graph with 30 vertices and 60 edges, one of the Archimedean graphs. It is quartic, meaning that each of its vertex is connected by four other vertices.
## Applications
The icosidodecahedron may appear in structures, as in the geodesic dome or the Hoberman sphere.
Icosidodecahedra can be found in all eukaryotic cells, including human cells, as Sec13/31 COPII coat-protein formations.`{{r|rs}}`{=mediawiki}
The icosidodecahedron may also found in popular culture. In Star Trek universe, the Vulcan game of logic Kal-Toh has the goal of creating a shape with two nested holographic icosidodecahedra joined at the midpoints of their segments
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# International Seabed Authority
The **International Seabed Authority** (**ISA**; *Autorité internationale des fonds marins*) is a Kingston, Jamaica-based intergovernmental body of 167 member states and the European Union. It was established under the 1982 UN Convention on the Law of the Sea (UNCLOS) and its 1994 Agreement on Implementation. The ISA\'s dual mission is to authorize and control the development of mineral related operations in the international seabed, which is considered the \"common heritage of all mankind\", and to protect the ecosystem of the seabed, ocean floor and subsoil in \"The Area\" beyond national jurisdiction. The ISA is responsible for safeguarding the international deep sea, defined as waters below 200 meters (656 feet), where photosynthesis is hampered by inadequate light. Governing approximately half of the total area of the world\'s oceans, the ISA oversees activities that might threaten biological diversity and harm the marine environment.
Since its inception in 1994, the ISA has approved over two dozen ocean floor mining exploration contracts in the Atlantic, Pacific and Indian Oceans. The majority of these contracts are for exploration in the Clarion--Clipperton zone between Hawaii and Mexico, where polymetallic nodules contain copper, cobalt and other minerals essential for powering electric batteries. To date, the Authority has not authorized any commercial mining contracts as it continues to deliberate over regulations amid global calls for a moratorium on deep sea mining. Scientists and environmentalists warn that such mining could wreak havoc on the ocean, a crucial carbon sink and home to rare and diverse species.
Funded by UNCLOS members and mining contractors, the Authority operates as an autonomous international organization with its own Assembly, Council, and Secretariat. The current secretary-general of the agency is Leticia Carvalho, whose four-year term began on 1 January 2025.
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# International Seabed Authority
## Origin
The Authority held its inaugural meeting in its host country, Jamaica, on 16 November 1994, the day the Convention came into force. The articles governing the Authority have been made \"noting the political and economic changes, including market-oriented approaches, affecting the implementation\" of the convention. The Authority obtained its observer status to the United Nations in October 1996. The Authority has 167 members and the European Union, composed of all parties to the United Nations Convention on the Law of the Sea. The Authority operates by contracting with private and public corporations and other entities authorizing them to explore, and potentially exploit, specified areas on the deep seabed for mineral resources, such as cobalt, nickel and manganese.
### \"Common Heritage of All Mankind\" {#common_heritage_of_all_mankind}
Under UNCLOS, Part XI, Section 2. \"The Area and its resources are the common heritage of mankind.\" As a result, ISA must ensure that activities in the Area are undertaken only for peaceful purposes and for the benefit of all humankind, with economic benefits shared equitably and special consideration given to the needs of developing nations.
### Governance and operations {#governance_and_operations}
Along with a Secretary-General, two principal organs establish the policies and govern the work of the Authority: the Assembly, in which all UNCLOS parties are represented, and a 36-member Council elected by the Assembly.
#### Secretary-General {#secretary_general}
The Assembly elects a Secretary-General to serve a four-year term as the ISA\'s chief administrative officer, oversee Authority staff and issue an annual report to the Assembly. The Secretary-General is prohibited from holding a financial interest in any mining operations authorized by the Authority.
There have been four Secretary-Generals since ISA\'s creation in 1996:
Country Image Name Term
--------- ------- --------------------- ------------
Satya Nandan 1996--2008
Nii Allotey Odunton 2008−2016
Michael Lodge 2016--2024
Leticia Carvalho 2025--
#### Assembly
The Assembly, which consists of all members of the Authority, elects the 36-member Council, as well as the Secretary-General from among candidates the Council recommends. The Assembly also has the power to approve or reject the council\'s recommendations for the following: rules and regulations governing seabed mining, distribution of financial benefits accrued from authorized mining and the Authority\'s annual budget.
#### Council
The 36-member Council, elected by the Assembly, authorizes contracts with governments and private corporations to explore and mine the international seabed and sets rules and procedures, subject to the Assembly\'s approval, for ISA governance. The council also nominates a Secretary-General, who then must be elected by the full Assembly to serve a four-year term. The ISA\'s annual plenary sessions, which usually last two weeks, are held in Kingston.
#### Advisory bodies {#advisory_bodies}
Also established is a 30-member Legal and Technical Commission which advises the Council and a 15-member Finance Committee that deals with budgetary and related matters. All members are experts nominated by governments and elected to serve in their individual capacity.
#### Enterprise
The convention also established a body called the Enterprise which is to serve as the Authority\'s own mining operator, potentially generating \"hundreds of millions of dollars in royalties\" to be shared with developing nations.\" The environmental organization Greenpeace has expressed concerns over the ISA\'s alleged conflict of interest as both regulator and business operator, though the ISA denies the conflict of interest charge.
## Status
The Authority has a Secretariat of 37 authorized posts and a 2022 biennial budget of approximately \$10,000,000.
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# International Seabed Authority
## Jurisdiction
UNCLOS defines the international seabed area---the part under ISA jurisdiction---as \"the seabed and ocean floor and the subsoil thereof, beyond the limits of national jurisdiction\" UNCLOS outlines the areas of national jurisdiction as a \"12 nautical-mile territorial sea; an exclusive economic zone of up to 200 nautical miles and a continental shelf\", unless a nation can demonstrate that its continental shelf is naturally prolonged beyond that limit, in which case it may claim up to 350 nmi. ISA has no role in determining this boundary. Rather, this task is left to another body established by UNCLOS, the Commission on the Limits of the Continental Shelf, which examines scientific data submitted by coastal states that claim a broader reach.
## Exploration contracts and commercial mining {#exploration_contracts_and_commercial_mining}
### Commercial
Although the ISA has yet to approve commercial mining contracts, the Authority anticipates commercial mining could begin as early as 2023--2024 with the completion of much-debated ISA regulations. In 2021, the Pacific Island nation of Nauru triggered a deadline that requires the ISA to approve final commercial mining regulations by July 2023 or allow contractors to mine under existing draft regulations.
### Exploratory
Exploratory mining involves \"deep-sea mapping, manned submersibles or remotely-operated vehicles, photographic and video systems, and drilling devices.\"
#### Clarion--Clipperton zone {#clarionclipperton_zone}
Most areas of exploration are in the Clarion--Clipperton zone (CCZ), in the Equatorial North Pacific Ocean, south and southeast of Hawaii, between Hawaii and Mexico. The quiet CCZ, as wide as the continental U.S., is home to polymetallic nodules or trillions of potato-size lumps of matter formed over millions of years that contain nickel, manganese, copper, zinc and cobalt, as well as deep water coral, sponges and unusual species (\"ghost octopus\", crustaceans, worms and sea cucumbers) that in a near light-less environment attach to the rock-like nodules for shelter. Contractors want to mine polymetallic nodules for battery storage for electric vehicles, smartphones, and solar and wind energy.
#### Other areas of exploration {#other_areas_of_exploration}
Exploration contracts for polymetallic nodules have also been issued for contractors operating in the Central Indian Ocean Basin and Western Pacific Ocean. The ISA has issued exploration contracts for polymetallic sulphides in the South West Indian Ridge, Central Indian Ridge and the Mid-Atlantic Ridge, and contracts for exploration for cobalt-rich crusts in the Western Pacific Ocean.
#### Requirements of contractors {#requirements_of_contractors}
Each contractor is required to develop a contingency plan should something go wrong during exploration, report annually on its activities in its assigned area and propose a training program for developing countries .
#### List of exploratory contractors {#list_of_exploratory_contractors}
The ISA has signed 15-year contracts for exploration with 22 contractors seeking polymetallic nodules, polymetallic sulphides and cobalt-rich ferromanganese crusts in the deep seabed.
In 2001-2002 the ISA signed contracts with Yuzhmorgeologya (Russian Federation); Interoceanmetal Joint Organization (IOM) (Bulgaria, Cuba, Slovakia, Czech Republic, Poland and Russian Federation); the Government of the Republic of Korea; China Ocean Minerals Research and Development Association (COMRA) (China); Deep Ocean Resources Development Company (DORD) (Japan); Institut français de recherche pour l'exploitation de la mer (IFREMER) (France); the Government of India. In 2006, the Authority signed a 15-year contract with the Federal Institute for Geosciences and Natural Resources of Germany.
In 2008, the Authority received two new applications for authorization to explore for polymetallic nodules, coming for the first time from private firms in developing island nations of the Pacific. Sponsored by their respective governments, they were submitted by Nauru Ocean Resources Inc. and Tonga Offshore Mining Limited. A 15-year exploration contract was granted by the Authority to Nauru Ocean Resources Inc. on 22 July 2011 and to Tonga Offshore Mining Limited on 12 January 2012.
Fifteen-year exploration contracts for polymetallic nodules were also granted to G-TECH Sea Mineral Resources NV (Belgium) on 14 January 2013; Marawa Research and Exploration Ltd (Kiribati) on 19 January 2015; Ocean Mineral Singapore Pte Ltd on 22 January 2015; UK Seabed Resources Ltd (two contracts on 8 February 2013 and 29 March 2016 respectively); Cook Islands Investment Corporation on 15 July 2016 and more recently China Minmetals Corporation on 12 May 2017.
The Authority has signed seven contracts for the exploration for polymetallic sulphides in the South West Indian Ridge, Central Indian Ridge and Mid-Atlantic Ridge with China Ocean Mineral Resources Research and Development Association (18 November 2011); the Government of Russia (29 October 2012); Government of the Republic of Korea (24 June 2014); Institut français de recherche pour l'exploitation de la mer (Ifremer, France, 18 November 2014); the Federal Institute for Geosciences and Natural Resources of Germany (6 May 2015); and the Government of India (26 September 2016) and the Government of the Republic of Poland (12 February 2018).
The Authority holds five contracts for the exploration of cobalt-rich ferromanganese crusts in the Western Pacific Ocean with China Ocean Mineral Resources Research and Development Association (29 April 2014); Japan Oil Gas and Metals National Corporation (JOGMEC, 27 January 2014); Ministry of Natural Resources and Environment of the Russian Federation (10 March 2015), Companhia De Pesquisa de Recursos Minerais (9 November 2015) and the Government of the Republic of Korea (27 March 2018).
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# International Seabed Authority
## Controversy
### Environmental concerns and climate crisis {#environmental_concerns_and_climate_crisis}
Environmentalists, scientists from 44 countries, Google, BMW and Volvo, World Wildlife Fund and several Pacific nations, including Fiji and Papua New Guinea, have called for a moratorium on deep-sea mining until more scientific research is conducted on its impact on the marine environment.
Advocates for deep sea mining argue extraction of rare metals is critical for electric car batteries necessary to develop a fossil-free economy.
Opponents argue seabed mining could wreak havoc on the world\'s oceans, which act as a carbon sink absorbing a quarter of the world\'s carbon emissions each year. The environmental organization Greenpeace has raised objections about deep seabed mining disrupting the habitats of newly reported species, from crabs to whales to snails that survive without eating and congregate near bioluminescent thermal vents. Greenpeace has urged the ISA to further develop UNCLOS\' foundational Article 136 principle \"of common heritage to all mankind\" to revise regulations and set conservation targets. In a 2018 Greenpeace Research Laboratories report the organization stressed the importance of protecting marine biodiversity from toxins released during seabed mining for natural gas and rare metals for photovoltaic cells. Greenpeace maintains the \"pro-exploitation\" ISA is not the appropriate authority to regulate deep sea mining (DSM). In 2019 Greenpeace activists protested outside the annual meeting of the International Seabed Authority in Jamaica, calling for a global ocean treaty to ban deep sea mining in ocean sanctuaries. Some of the activists had sailed to Jamaica aboard Greenpeace\'s ship, the Esperanza, which travelled from the \"Lost City in the mid-Atlantic\", an area Greenpeace says is threatened by exploratory mining the ISA authorized.
ISA Secretary-General Michael Lodge said Greenpeace\'s support for a global ocean treaty, not the ISA, to control deep sea mining did not make sense.
### Concern over transparency issues {#concern_over_transparency_issues}
In 2022, The Guardian reported the ISA failed to renew the contract for Earth Negotiations Bulletin (ENB), a division of the International Institute for Sustainable Development (IISD), which covered past proceedings to maintain an independent record of the ISA. The decision came amid warnings from scientists that commercial ocean floor mining \"would be "dangerous", "reckless" and "irreversible" in its harm to the ecosystem. In its defense, the ISA said ENB\'s non-renewal was triggered by budget cuts. The Guardian also reported that Germany and environmentalists had raised questions about the lack of transparency by the ISA\'s Legal and Technical Commission (LTC), which conducts closed meetings to set standards and issue guidelines for seabed mining.
In response to criticism, ISA Secretary-General Michael Lodge defended ISA as a \"transparent public forum of consensus-building.\"
### Charges of conflict of interest {#charges_of_conflict_of_interest}
In 2022, the *Los Angeles Times* reported that the International Seabed Authority faced criticisms over conflicts of interest. The *LA Times* reported that the ISA was scheduled to approve seabed mining, despite concerns by scientists and environmentalists about the environmental impact. ISA head Michael Lodge had criticized these groups, saying there was \"a growing environmental absolutism and dogmatism bordering on fanaticism\" and arguing that seabed mining was \"predictable and manageable\". Scientists and members of Lodge\'s staff objected to Lodge\'s appearance in a mining company video seeking investments in robotic exploration for minerals to manufacture electric vehicles. In the video, Lodge said his agency supported a 15-year exploration contract because \"land-based resources are becoming increasingly difficult to access.\"
### United States\' non-ratification of UNCLOS {#united_states_non_ratification_of_unclos}
The exact nature of the ISA\'s mission and authority has been questioned by opponents of the Law of the Sea Treaty who are generally skeptical of multilateral engagement by the United States. In 2007, although the US Senate Foreign Relations Committee voted in favor of treaty ratification, the full Senate failed to ratify the treaty, with some Republicans arguing UNCLOS might threaten national security by interfering with ocean military operations and hinder seabed mining corporations by imposing environmental regulations.
One of the main anti-ratification arguments being a charge that the ISA is flawed or unnecessary. In its original form, the Convention included certain provisions that some found objectionable, such as:
- Use of collected money for wealth redistribution in addition to ISA administration
- Mandatory technology transfer
Because of these concerns, the United States pushed for modification of the Convention, obtaining a 1994 Agreement on Implementation that somewhat mitigates them and thus modifies the ISA\'s authority. Despite this change the United States has not ratified the Convention and so is not a member of ISA, although it sends sizable delegations to participate in meetings as an observer.
As an observer, not an UNCLOS signatory, the U.S. will not be allowed to vote on approval of final commercial mining regulations and will be unable to sponsor companies to apply for contracts in international waters. This is because the ISA requires contractors be sponsored by a state that is a signatory to UNCLOS. U.S.-based military contractor Lockheed Martin, however, is participating in two British deep sea mining projects.
### Palau\'s advocacy against deep-sea mining {#palaus_advocacy_against_deep_sea_mining}
Palau was the first country to call for a moratorium, or precautionary pause, on deep-sea mining until the impact of such a practice is better understood. By July 10, 2023, 17 countries had called for a deep-sea mining moratorium or pause, including Germany, New Zealand, Spain, France, Sweden, Fiji, and the Federated States of Micronesia.
On July 29, 2024, President Surangel S. Whipps Jr. of Palau delivered an address titled \"Upholding the Common Heritage of Humankind\" to the 29th General Assembly of the International Seabed Authority (ISA) in Kingston, Jamaica. In his speech, President Whipps emphasized the importance of safeguarding the deep ocean from exploitation and modern-day colonialism. He highlighted Palau's deep cultural and economic ties to the ocean and reiterated the call for an immediate moratorium on deep-sea mining, citing the associated environmental risks and uncertainties. In his speech he referred to the ocean as \"Our greatest ally in our fight against climate change,\" highlighting its role as the largest carbon sink on the planet. He underscored the critical role deep ocean ecosystems play in global environmental health and advocated for prioritizing long-term sustainability over short-term economic gains. He urged the assembly to act responsibly on behalf of future generations, reinforcing the deep seabed's status as the \"common heritage of (hu)mankind.\"
The number of countries against the imminent start of mining for metallic nodules on the seafloor increased to 32 during the 29th ISA annual assembly, with Austria, Guatemala, Honduras, Malta, and Tuvalu joining the list.
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# International Seabed Authority
## Activities
### Legislative
The Authority\'s main legislative accomplishment has been the adoption, in the year 2000, of regulations governing exploration for polymetallic nodules. These resources, also called manganese nodules, contain varying amounts of manganese, cobalt, copper and nickel. They occur as potato-sized lumps scattered about on the surface of the ocean floor, mainly in the central Pacific Ocean in the Clarion--Clipperton zone but with some deposits in the Indian Ocean.
In 2013, the ISA approved amendments to its mining code on deep sea exploration, stating a prospector should take a precautionary approach to avoid polluting the ocean and should immediately inform the Secretary-General of any prospect-related incidents that threaten the marine environment. The amended regulations also said a contractor can recover \"a reasonable amount of material\" for testing but not for sale.
In July 2019, the ISA\'s Legal and Trade Commission prepared \"Draft regulations on exploitation of mineral resources in the Area.\"
In 2010, the ISA adopted Regulations on Prospecting and Exploration for Polymetallic Sulphides.
In 2012, the Authority adopted Regulations on Prospecting and Exploration for Cobalt-Rich Ferromanganese Crusts.
The Council of the Authority began work in August 2002 on another set of regulations, covering polymetallic sulfides and cobalt-rich ferromanganese crusts, which are rich sources of such minerals as copper, iron, zinc, silver and gold, as well as cobalt. The sulphides are found around volcanic hot springs, especially in the western Pacific Ocean, while the crusts occur on oceanic ridges and elsewhere at several locations around the world. The Council decided in 2006 to prepare separate sets of regulations for sulphides and for crusts, with priority given to sulphides. It devoted most of its sessions in 2007 and 2008 to this task, but several issues remained unresolved. Chief among these were the definition and configuration of the area to be allocated to contractors for exploration, the fees to be paid to the Authority and the question of how to deal with any overlapping claims that might arise. Meanwhile, the Legal and Technical Commission reported progress on ferromanganese crusts.
### Workshops and research {#workshops_and_research}
In addition to its legislative work, the Authority organizes annual workshops on various aspects of seabed exploration, with emphasis on measures to protect the marine environment from any harmful consequences. It disseminates the results of these meetings through publications. Studies over several years covering the key mineral area of the Central Pacific resulted in a technical study on biodiversity, species ranges and gene flow in the abyssal Pacific nodule province, with emphasis on predicting and managing the impacts of deep seabed mining A workshop at Manoa, Hawaii, in October 2007 produced a rationale and recommendations for the establishment of \"preservation reference areas\" in the Clarion--Clipperton zone, where nodule mining would be prohibited in order to leave the natural environment intact. In recent years, the ISA hosted workshops on enhancing the role of women in conducting deep-sea scientific studies, sustainable management of deep seabed resources, a series for Africa on resources and technologies for DSM and a session on sharing the economic benefits of DSM.
## National trends in seabed mining {#national_trends_in_seabed_mining}
In recent years, however, interest in deep sea mining, especially with regard to ferromanganese crusts and polymetallic sulphides, has picked up among several firms now operating in waters within the national zones of Papua New Guinea, Fiji and Tonga. Papua New Guinea was the first country in the world to grant commercial exploration licenses for seafloor massive sulphide deposits when it granted the initial license to Nautilus Minerals in 1997. Japan\'s new ocean policy emphasizes the need to develop methane hydrate and hydrothermal deposits within Japan\'s exclusive economic zone and calls for the commercialization of these resources within the next 10 years. Reporting on these developments in his annual report to the Authority in April 2008, Secretary-General Nandan referred also to the upward trend in demand and prices for cobalt, copper, nickel and manganese, the main metals that would be derived from seabed mining, and he noted that technologies being developed for offshore extraction could be adapted for deep sea mining.
Recently, there has been much interest in the possibility of exploiting seabed resources in the Arctic Ocean, bordered by Canada, Denmark, Iceland, Norway, Russia and the United States (see Territorial claims in the Arctic). In 2020, an international coalition of environmental groups urged the government of Norway to not only abandon plans for deep sea mining under national jurisdiction, but to also speak out against DSM Arctic mining before the International Seaboard Authority.
## Endowment fund {#endowment_fund}
In 2006 the Authority established an Endowment Fund to Support Collaborative Marine Scientific Research on the International Seabed Area. The Fund will aid experienced scientists and technicians from developing countries to participate in deep-sea research organized by international and national institutions. A campaign was launched in February 2008 to identify participants, establish a network of cooperating bodies and seek outside funds to augment the initial \$3 million endowment from the Authority.
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# International Seabed Authority
## Voluntary commitments {#voluntary_commitments}
In 2017, the Authority registered seven voluntary commitments with the UN Oceans Conference for Sustainable Development Goal 14. These were:`{{clarify|reason=8 in ref, 7 in this phrase, 6 listed below|date=March 2024}}`{=mediawiki}
1. OceanAction15467 -- Enhancing the role of women in marine scientific research through capacity building
2. OceanAction15796 -- Encouraging dissemination of research results through the ISA Secretary-General Award for Excellence in Deep-Sea Research
3. OceanAction16538 -- Abyssal Initiative for Blue Growth (with UN-DESA)
4. OceanAction16494 -- Fostering cooperation to promote the sustainable development of Africa\'s deep seabed resources in support of Africas Blue Economy
5. OceanAction17746 -- Enhancing the assessment of essential ecological functions of the deep sea oceans through long-term underwater oceanographic observatories in the Area;
6
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# Industry Standard Architecture
**Industry Standard Architecture** (**ISA**) is the 16-bit internal bus of IBM PC/AT and similar computers based on the Intel 80286 and its immediate successors during the 1980s. The bus was (largely) backward compatible with the 8-bit bus of the 8088-based IBM PC, including the IBM PC/XT as well as IBM PC compatibles.
Originally referred to as the **PC bus** (8-bit) or **AT bus** (16-bit), it was also termed *I/O Channel* by IBM. The ISA term was coined as a retronym by IBM PC clone manufacturers in the late 1980s or early 1990s as a reaction to IBM attempts to replace the AT bus with its new and incompatible Micro Channel architecture.
The 16-bit ISA bus was also used with 32-bit processors for several years. An attempt to extend it to 32 bits, called Extended Industry Standard Architecture (EISA), was not very successful, however. Later buses such as VESA Local Bus and PCI were used instead, often along with ISA slots on the same mainboard. Derivatives of the AT bus structure were and still are used in ATA/IDE, the PCMCIA standard, CompactFlash, the PC/104 bus, and internally within Super I/O chips.
Even though ISA disappeared from consumer desktops many years ago, it is still used in industrial PCs, where certain specialized expansion cards that never transitioned to PCI and PCI Express are used.
## History
thumb\|upright=1.25\|`{{nowrap|8-bit XT}}`{=mediawiki}, `{{nowrap|16-bit ISA}}`{=mediawiki}, EISA (top to bottom) thumb\|upright=1.25\|`{{nowrap|8-bit XT}}`{=mediawiki}: Adlib FM Sound card thumb\|upright=1.25\|`{{nowrap|16-bit ISA}}`{=mediawiki}: Madge 4/16 Mbps Token Ring NIC thumb\|upright=1.25\|`{{nowrap|16-bit ISA}}`{=mediawiki}: Ethernet 10BASE-5/2 NIC thumb\|upright=1.25\|`{{nowrap|8-bit XT}}`{=mediawiki}: US Robotics 56k Modem
The original PC bus was developed by a team led by Mark Dean at IBM as part of the IBM PC project in 1981. It was an 8-bit bus based on the I/O bus of the IBM System/23 Datamaster system - it used the same physical connector, and a similar signal protocol and pinout. A 16-bit version, the IBM AT bus, was introduced with the release of the IBM PC/AT in 1984. The AT bus was a mostly backward-compatible extension of the PC bus---the AT bus connector was a superset of the PC bus connector. In 1988, the 32-bit EISA standard was proposed by the \"Gang of Nine\" group of PC-compatible manufacturers that included Compaq. Compaq created the term *Industry Standard Architecture* (ISA) to replace *PC compatible*. In the process, they retroactively renamed the AT bus to ISA to avoid infringing IBM\'s trademark on its PC and PC/AT systems (and to avoid giving their major competitor, IBM, free advertisement).
IBM designed the 8-bit version as a buffered interface to the motherboard buses of the Intel 8088 (16/8 bit) CPU in the IBM PC and PC/XT, augmented with prioritized interrupts and DMA channels. The 16-bit version was an upgrade for the motherboard buses of the Intel 80286 CPU (and expanded interrupt and DMA facilities) used in the IBM AT, with improved support for bus mastering. The ISA bus was therefore synchronous with the CPU clock until sophisticated buffering methods were implemented by chipsets to interface ISA to much faster CPUs.
ISA was designed to connect peripheral cards to the motherboard and allows for bus mastering. Only the first 16 MB of main memory is addressable. The original 8-bit bus ran from the 4.77 MHz clock of the 8088 CPU in the IBM PC and PC/XT. The original 16-bit bus ran from the CPU clock of the 80286 in IBM PC/AT computers, which was 6 MHz in the first models and 8 MHz in later models. The IBM RT PC also used the 16-bit bus. ISA was also used in some non-IBM compatible machines such as Motorola 68k-based Apollo (68020) and Amiga 3000 (68030) workstations, the short-lived AT&T Hobbit and the later PowerPC-based BeBox.
Companies like Dell improved the AT bus\'s performance but in 1987, IBM replaced the AT bus with its proprietary Micro Channel Architecture (MCA). MCA overcame many of the limitations then apparent in ISA but was also an effort by IBM to regain control of the PC architecture and the PC market. MCA was far more advanced than ISA and had many features that would later appear in PCI. However, MCA was also a closed standard whereas IBM had released full specifications and circuit schematics for ISA. Computer manufacturers responded to MCA by developing the Extended Industry Standard Architecture (EISA) and the later VESA Local Bus (VLB). VLB used some electronic parts originally intended for MCA because component manufacturers were already equipped to manufacture them. Both EISA and VLB were backward-compatible expansions of the AT (ISA) bus.
Users of ISA-based machines had to know special information about the hardware they were adding to the system. While a handful of devices were essentially plug-n-play, this was rare. Users frequently had to configure parameters when adding a new device, such as the IRQ line, I/O address, or DMA channel. MCA had done away with this complication and PCI actually incorporated many of the ideas first explored with MCA, though it was more directly descended from EISA.
This trouble with configuration eventually led to the creation of **ISA PnP**, a plug-n-play system that used a combination of modifications to hardware, the system BIOS, and operating system software to automatically manage resource allocations. In reality, ISA PnP could be troublesome and did not become well-supported until the architecture was in its final days.
A PnP ISA, EISA or VLB device may have a 5-byte *EISA ID* (3-byte manufacturer ID + 2-byte hex number) to identify the device. For example, CTL0044 corresponds to Creative Sound Blaster 16/32 PnP.
PCI slots were the first physically incompatible expansion ports to directly squeeze ISA off the motherboard. At first, motherboards were largely ISA, including a few PCI slots. By the mid-1990s, the two slot types were roughly balanced, and ISA slots soon were in the minority of consumer systems. Microsoft\'s PC-99 specification recommended that ISA slots be removed entirely, though the system architecture still required ISA to be present in some vestigial way internally to handle the floppy drive, serial ports, etc., which was why the software compatible LPC bus was created. ISA slots remained for a few more years and towards the turn of the century it was common to see systems with an Accelerated Graphics Port (AGP) sitting near the central processing unit, an array of PCI slots, and one or two ISA slots near the end. In late 2008, even floppy disk drives and serial ports were disappearing, and the extinction of vestigial ISA (by then the LPC bus) from chipsets was on the horizon.
PCI slots are rotated compared to their ISA counterparts---PCI cards were essentially inserted upside-down, allowing ISA and PCI connectors to squeeze together on the motherboard. Only one of the two connectors can be used in each slot at a time, but this allowed for greater flexibility.
The AT Attachment (ATA) hard disk interface is directly descended from the 16-bit ISA of the PC/AT. ATA has its origins in the IBM Personal Computer Fixed Disk and Diskette Adapter, the standard dual-function floppy disk controller and hard disk controller card for the IBM PC AT; the fixed disk controller on this card implemented the register set and the basic command set which became the basis of the ATA interface (and which differed greatly from the interface of IBM\'s fixed disk controller card for the PC XT). Direct precursors to ATA were third-party ISA hardcards that integrated a hard disk drive (HDD) and a hard disk controller (HDC) onto one card. This was at best awkward and at worst damaging to the motherboard, as ISA slots were not designed to support such heavy devices as HDDs. The next generation of Integrated Drive Electronics drives moved both the drive and controller to a drive bay and used a ribbon cable and a very simple interface board to connect it to an ISA slot. ATA is basically a standardization of this arrangement plus a uniform command structure for software to interface with the HDC within the drive. ATA has since been separated from the ISA bus and connected directly to the local bus, usually by integration into the chipset, for much higher clock rates and data throughput than ISA could support. ATA has clear characteristics of 16-bit ISA, such as a 16-bit transfer size, signal timing in the PIO modes and the interrupt and DMA mechanisms.
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# Industry Standard Architecture
## ISA bus architecture {#isa_bus_architecture}
+---+---+
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+---+---+
The **PC/XT-bus** is an eight-bit ISA bus used by Intel 8086 and Intel 8088 systems in the IBM PC and IBM PC XT in the 1980s. Among its 62 pins were demultiplexed and electrically buffered versions of the 8 data and 20 address lines of the 8088 processor, along with power lines, clocks, read/write strobes, interrupt lines, etc. Power lines included −5 V and ±12 V in order to directly support pMOS and enhancement mode nMOS circuits such as dynamic RAMs among other things. The XT bus architecture uses a single Intel 8259 PIC, giving eight vectorized and prioritized interrupt lines. It has four DMA channels originally provided by the Intel 8237. Three of the DMA channels are brought out to the XT bus expansion slots; of these, 2 are normally already allocated to machine functions (diskette drive and hard disk controller):
DMA channel Expansion Standard function
------------- ----------- --------------------------------------
0 No Dynamic random-access memory refresh
1 Yes Add-on cards
2 Yes Floppy disk controller
3 Yes Hard disk controller
The **PC/AT-bus**, a 16-bit (or 80286-) version of the PC/XT bus, was introduced with the IBM PC/AT. This bus was officially termed *I/O Channel* by IBM. It extends the XT-bus by adding a second shorter edge connector in-line with the eight-bit XT-bus connector, which is unchanged, retaining compatibility with most 8-bit cards. The second connector adds four additional address lines for a total of 24, and 8 additional data lines for a total of 16. It also adds new interrupt lines connected to a second 8259 PIC (connected to one of the lines of the first) and 4 × 16-bit DMA channels, as well as control lines to select 8- or 16-bit transfers.
The 16-bit AT bus slot originally used two standard edge connector sockets in early IBM PC/AT machines. However, with the popularity of the AT architecture and the 16-bit ISA bus, manufacturers introduced specialized 98-pin connectors that integrated the two sockets into one unit. These can be found in almost every AT-class PC manufactured after the mid-1980s. The ISA slot connector is typically black (distinguishing it from the brown EISA connectors and white PCI connectors).
### Number of devices {#number_of_devices}
Motherboard devices have dedicated IRQs (not present in the slots). 16-bit devices can use either PC-bus or PC/AT-bus IRQs. It is therefore possible to connect up to 6 devices that use one 8-bit IRQ each and up to 5 devices that use one 16-bit IRQ each. At the same time, up to 4 devices may use one 8-bit DMA channel each, while up to 3 devices can use one 16-bit DMA channel each.
### Varying bus speeds {#varying_bus_speeds}
Originally, the bus clock was synchronous with the CPU clock, resulting in varying bus clock frequencies among the many different IBM clones on the market (sometimes as high as 16 or 20 MHz), leading to software or electrical timing problems for certain ISA cards at bus speeds they were not designed for. Later motherboards or integrated chipsets used a separate clock generator, or a clock divider which either fixed the ISA bus frequency at 4, 6, or 8 MHz or allowed the user to adjust the frequency via the BIOS setup. When used at a higher bus frequency, some ISA cards (certain Hercules-compatible video cards, for instance), could show significant performance improvements.
### 8/16-bit incompatibilities {#bit_incompatibilities}
Memory address decoding for the selection of 8 or 16-bit transfer mode was limited to 128 KB sections, leading to problems when mixing 8- and 16-bit cards as they could not co-exist in the same 128 KB area. This is because the MEMCS16 line is required to be set based on the value of LA17-23 only.
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# Industry Standard Architecture
## Past and current use {#past_and_current_use}
ISA is still used today for specialized industrial purposes. In 2008, IEI Technologies released a modern motherboard for Intel Core 2 Duo processors which, in addition to other special I/O features, is equipped with two ISA slots. It was marketed to industrial and military users who had invested in expensive specialized ISA bus adaptors, which were not available in PCI bus versions.
Similarly, ADEK Industrial Computers released a modern motherboard in early 2013 for Intel Core i3/i5/i7 processors, which contains one (non-DMA) ISA slot. Also, MSI released a modern motherboard with one ISA slot in 2020, for use with Skylake and Kaby Lake Intel processors; per its official specifications, it can be accessed within the 32-bit Windows 7 installation. DFI also released a motherboard featuring two ISA slots, for use with Coffee Lake Intel processors; in this example, due to ISA\'s historic nature, they can only be accessed within KVM-based virtual machines.
The PC/104 bus, used in industrial and embedded applications, is a derivative of the ISA bus, utilizing the same signal lines with different connectors. The LPC bus has replaced the ISA bus as the connection to the legacy I/O devices on current motherboards; while physically quite different, LPC looks just like ISA to software, so the peculiarities of ISA such as the 16 MiB DMA limit (which corresponds to the full address space of the Intel 80286 CPU used in the original IBM AT) are likely to stick around for a while.
### ATA
As explained in the *History* section, ISA was the basis for development of the ATA interface, used for ATA (a.k.a. IDE) hard disks. Physically, ATA is essentially a simple subset of ISA, with 16 data bits, support for exactly one IRQ and one DMA channel, and 3 address bits. To this ISA subset, ATA adds two IDE address select (\"chip select\") lines (i.e. address decodes, effectively equivalent to address bits) and a few unique signal lines specific to ATA/IDE hard disks (such as the Cable Select/Spindle Sync. line.) In addition to the physical interface channel, ATA goes beyond and far outside the scope of ISA by also specifying a set of physical device registers to be implemented on every ATA (IDE) drive and a full set of protocols and device commands for controlling fixed disk drives using these registers. The ATA device registers are accessed using the address bits and address select signals in the ATA physical interface channel, and all operations of ATA hard disks are performed using the ATA-specified protocols through the ATA command set. The earliest versions of the ATA standard featured a few simple protocols and a basic command set comparable to the command sets of MFM and RLL controllers (which preceded ATA controllers), but the latest ATA standards have much more complex protocols and instruction sets that include optional commands and protocols providing such advanced optional-use features as sizable hidden system storage areas, password security locking, and programmable geometry translation.
In the mid-1990s, the ATA host controller (usually integrated into the chipset) was moved to PCI form. A further deviation between ISA and ATA is that while the ISA bus remained locked into a single standard clock rate (for backward hardware compatibility), the ATA interface offered many different speed modes, could select among them to match the maximum speed supported by the attached drives, and kept adding faster speeds with later versions of the ATA standard (up to `{{nowrap|133 MB/s}}`{=mediawiki} for ATA-6, the latest.) In most forms, ATA ran much faster than ISA, provided it was connected directly to a local bus (e.g. southbridge-integrated IDE interfaces) faster than the ISA bus.
### XT-IDE {#xt_ide}
Before the 16-bit ATA/IDE interface, there was an 8-bit XT-IDE (also known as XTA) interface for hard disks. It was not nearly as popular as ATA has become, and XT-IDE hardware is now fairly hard to find. Some XT-IDE adapters were available as 8-bit ISA cards, and XTA sockets were also present on the motherboards of Amstrad\'s later XT clones as well as a short-lived line of Philips units. The XTA pinout was very similar to ATA, but only eight data lines and two address lines were used, and the physical device registers had completely different meanings. A few hard drives (such as the Seagate ST351A/X) could support either type of interface, selected with a jumper.
Many later AT (and AT successor) motherboards had no integrated hard drive interface but relied on a separate hard drive interface plugged into an ISA/EISA/VLB slot. There were even a few 80486-based units shipped with MFM/RLL interfaces and drives instead of the increasingly common AT-IDE.
Commodore built the XT-IDE-based peripheral hard drive and memory expansion unit A590 for their Amiga 500 and 500+ computers that also supported a SCSI drive. Later models -- the A600, A1200, and the Amiga 4000 series -- use AT-IDE drives.
### PCMCIA
The PCMCIA specification can be seen as a superset of ATA. The standard for PCMCIA hard disk interfaces, which included PCMCIA flash drives, allows for the mutual configuration of the port and the drive in an ATA mode. As a de facto extension, most PCMCIA flash drives additionally allow for a simple ATA mode that is enabled by pulling a single pin low, so that PCMCIA hardware and firmware are unnecessary to use them as an ATA drive connected to an ATA port. PCMCIA flash drive to ATA adapters are thus simple and inexpensive but are not guaranteed to work with any and every standard PCMCIA flash drive. Further, such adapters cannot be used as generic PCMCIA ports, as the PCMCIA interface is much more complex than ATA.
## Emulation by embedded chips {#emulation_by_embedded_chips}
Although most modern computers do not have physical ISA buses, almost all PCs --- IA-32, and x86-64 --- have ISA buses allocated in physical address space. Some Southbridges and some CPUs themselves provide services such as temperature monitoring and voltage readings through ISA buses as ISA devices.
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# Industry Standard Architecture
## Standardization
IEEE started a standardization of the ISA bus in 1985, called the P996 specification. However, despite books being published on the P996 specification, it never officially progressed past draft status.
## Modern ISA cards {#modern_isa_cards}
There still is an existing user base with old computers, so some ISA cards are still manufactured, e.g. with USB ports or complete single-board computers based on modern processors, USB 3.0, and SATA
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# Information Sciences Institute
The **USC Information Sciences Institute** (**ISI**) is a component of the University of Southern California (USC) Viterbi School of Engineering, and specializes in research and development in information processing, computing, and communications technologies. It is located in Marina del Rey, California.
ISI actively participated in the information revolution, and it played a leading role in developing and managing the early Internet and its predecessor ARPAnet. The Institute conducts basic and applied research supported by more than 20 U.S. government agencies involved in defense, science, health, homeland security, energy and other areas. Annual funding is about \$100 million.
ISI employs about 400 research scientists, research programmers, graduate students and administrative staff at its Marina del Rey, California headquarters, in Arlington, Virginia, and in Boston, Massachusetts. About half of the research staff hold PhD degrees, and about 40 are research faculty who teach at USC and advise graduate students. Several senior researchers are tenured USC faculty in the Viterbi School.
## Research and sponsors {#research_and_sponsors}
ISI research spans artificial intelligence (AI), cybersecurity, grid computing, cloud computing, quantum computing, microelectronics, supercomputing, nano-satellites and many other areas. AI expertise includes natural language processing, in which ISI has an international reputation, reconfigurable robotics, information integration, motion analysis and social media analysis. Hardware/software expertise includes cyber-physical system security, data mining, reconfigurable computing and cloud computing. In networking, ISI explores Internet resilience, Internet traffic analysis and photonics, among other areas. Researchers also work in scientific data management, wireless technologies, biomimetics and electrical smart grid, in which ISI is advising the Los Angeles Department of Water and Power on a major demonstration project. Another current initiative involves big data brain imaging jointly with the Keck School of Medicine of USC.
Federal agency sponsors include the Air Force Research Laboratory, DARPA, Department of Education, Department of Energy, Department of Homeland Security, National Institutes of Health, National Science Foundation, and other scientific, technical, and defense-related agencies.
Corporate partners include Chevron Corporation in the Center for Interactive Smart Oilfield Technologies (CiSoft), Lockheed Martin in the USC-Lockheed Martin Quantum Computing Center, and Sparta Inc., a subsidiary of Parsons Corporation in the DETER Project, a cybersecurity research initiative and international testbed. ISI also has partnered with businesses including IBM, Samsung Electronics, Raytheon, GlobalFoundries, Northrop Grumman and Carl Zeiss AG, and currently is working with Micron Technology, Inc., Altera Corporation and Fujitsu Ltd.
ISI also operates MOSIS, a multi-project electronic circuit wafer service that has prototyped more than 60,000 chips since 1981. MOSIS provides design tools and pools circuit designs to produce specialty and low-volume chips for corporations, universities and other research entities worldwide. The Institute also has given rise to several startup and spinoff companies in grid software, geospatial information fusion, machine translation, data integration and other technologies.
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# Information Sciences Institute
## History
ISI was founded by Keith Uncapher, who headed the computer research group at RAND Corporation in the 1960s and early 1970s. Uncapher decided to leave RAND after his group\'s funding was cut in 1971. He approached the University of California, Los Angeles about creating an off-campus technology institute, but was told that a decision would take 15 months. He then presented the concept to USC, which approved the proposal in five days. ISI was launched with three employees in 1972. Its first proposal was funded by the Defense Advanced Research Projects Agency (DARPA) in 30 days for \$6 million.
ISI became one of the earliest nodes on ARPANET, the predecessor to the Internet, and in 1977 figured prominently in a demonstration of its international viability. ISI also helped refine the TCP/IP communications protocols fundamental to Net operations, and researcher Paul Mockapetris developed the now-familiar Domain Name System characterized by .com, .org, .net, .gov, and .edu on which the Net still operates. (The names .com, .org et al. were invented at SRI International, an ongoing collaborator.) Steve Crocker originated the Request for Comments (RFC) series, the written record of the network\'s technical structure and operation that both documented and shaped the emerging Internet. Another ISI researcher, Danny Cohen, became first to implement packet voice and packet video over ARPANET, demonstrating the viability of packet switching for real-time applications.
Jonathan Postel collaborated in development of TCP/IP, DNS and the SMTP protocol that supports email. He also edited the RFC for nearly three decades until his sudden death in 1998, when ISI colleagues assumed responsibility. The Institute retained that role until 2009. Postel simultaneously directed the Internet Assigned Numbers Authority (IANA) and its predecessor, which assign Internet addresses. IANA was administered from ISI until a nonprofit organization, ICANN, was created for that purpose in 1998.
## Other achievements {#other_achievements}
Some of the first Net security applications, and one of the world\'s first portable computers, also originated at ISI.
ISI researchers also created or co-created the:
- GLOBUS grid computing standard
- LOOM knowledge representation language and environment, or LOOM (ontology)
- MONARCH supercomputer-on-a-chip
- Soar (cognitive architecture) for developing intelligent behavioral systems
- Pegasus (workflow management)
In 2011, several ISI natural language experts advised the IBM team that created Watson, the computer that became the first machine to win against human competitors on the *Jeopardy!* TV show. In 2012, ISI\'s Kevin Knight spearheaded a successful drive to crack the Copiale cipher, a lengthy encrypted manuscript that had remained unreadable for 250 years. Also in 2012, the USC-Lockheed Martin Quantum Computing Center (QCC) became the first organization to operate a quantum annealing system outside of its manufacturer, D-Wave Systems, Inc. USC, ISI and Lockheed Martin now are performing basic and applied research into quantum computing. A second quantum annealing system is located at NASA Ames Research Center, and is operated jointly by NASA and Google.
The USC Andrew and Erna Viterbi School of Engineering was ranked among the nation\'s top 10 engineering graduate schools by *US News & World Report* in 2015. Including ISI, USC is ranked first nationally in federal computer science research and development expenditures.
## Organizational structure {#organizational_structure}
ISI is organized into seven divisions focused on differing areas of research expertise:
- Advanced Electronics: MOSIS shared-services integrated circuit research and fabrication, CMOS and post-CMOS concepts, and biomimetics
- Computational Systems and Technology: quantum computing; supercomputing; cloud, wireless, reconfigurable and multicore computing; microarchitecture and electronics; science automation technologies; social networks and space systems
- Informatics Systems Research: grid computing, information security, service-oriented architectures, imaging and medical informatics that aim to transform healthcare discovery processes, practice and delivery.
- Artificial Intelligence: artificial intelligence in natural language, machine translation, information integration, education, robotics and other disciplines.
- Networking and Cybersecurity: internet security research and international testbed, internet measurement and monitoring approaches, and sensor networks that emphasize both networking theory and practice.
- Space Technology and Systems: space research and hands-on involvement for students through the Space Engineering Research Center, operated jointly by ISI and USC.
- Vision, Image, Speech and Text Analytics: ISI\'s Center for Vision, Image, Speech and Text Analytics (VISTA) is an internationally recognized leader in areas such as multimedia signal processing, computer vision, and natural language analysis.
Smaller, specialized research groups operate within almost all divisions.
ISI is led by Executive Director Craig Knoblock, the previous director to the AI division
| 736 |
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| 1 |
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# Ido
**Ido** (`{{IPAc-en|ˈ|iː|d|oʊ}}`{=mediawiki}) is a constructed language derived from a reformed version of Esperanto, and designed similarly with the goal of being a universal second language for people of diverse languages. To function as an effective *international auxiliary language*, Ido was designed specifically to be grammatically, orthographically, and lexicographically regular (and, above all, easy to learn and use). It is the most successful of the many Esperanto derivatives, known as *Esperantidoj.*
Ido was created in 1907 due to a desire to reform the perceived flaws of Esperanto, a language that had been created 20 years earlier to facilitate international communication. The name comes from the Esperanto word *`{{Wikt-lang|eo|ido}}`{=mediawiki}*, meaning \"offspring\", since the language is a derivative of Esperanto. After its inception, Ido was endorsed by some of the Esperanto community. A setback occurred with the sudden death in 1914 of one of its most influential proponents, Louis Couturat. In 1928, promoter Otto Jespersen quit the movement for his own language Novial.
The popularity of Ido decreased for two reasons: the emergence of further schisms developing from competing reform projects, and a general lack of awareness of Ido as a candidate for an international language. It was not until the spread of the Internet that it began to regain popularity.
Ido uses the same 26 letters as the English (Latin) alphabet, with no diacritics. It draws its vocabulary from English, French, German, Italian, Latin, Russian, Spanish and Portuguese, and is largely intelligible to those who have studied Esperanto.
Several works of literature have been translated into Ido, including *The Little Prince*, the Book of Psalms, and the Gospel of Luke. As of the year 2000, there were approximately 100--200 Ido speakers in the world. As of 2022, Ido has 26 speakers in Finland, according to Statistics Finland.
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# Ido
## History
The idea of a universal second language is not new, and constructed languages are not a recent phenomenon. During the 12th century Hildegard of Bingen invented a set of words known as the Lingua Ignota. The concept did not attract significant interest until the language Volapük was created in 1879. Volapük was popular for some time and apparently had a few thousand users, but was later eclipsed by the popularity of Esperanto, which was created in 1887. Several other languages, such as Latino sine Flexione and Idiom Neutral were also proposed. It was during this time that French mathematician Louis Couturat formed the *Delegation for the Adoption of an International Auxiliary Language*.
This delegation made a formal request to the International Association of Academies in Vienna to select and endorse an international language; the request was rejected in May 1907. The Delegation then met as a Committee in Paris in October 1907 to discuss the adoption of a standard international language. Among the languages considered was a new language submitted anonymously after the Committee\'s deadline by someone using the name *Ido*. In the end the committee, always without plenary sessions and consisting of only 12 members, concluded the last day with 4 votes for and 1 abstention. They concluded that no language was completely acceptable, but that Esperanto could be accepted \"on condition of several modifications to be realized by the permanent Commission in the direction defined by the conclusions of the Report of the Secretaries \[Louis Couturat and Léopold Leau\] and by the Ido project\".
Esperanto\'s inventor, L. L. Zamenhof, having heard a number of complaints, had suggested in 1894 a proposal for a reformed Esperanto with several changes that Ido adopted: eliminating the accented letters and the accusative case, changing the plural to an Italianesque *-i*, and replacing the table of correlatives with more Latinate words. However, the Esperanto community voted and rejected Zamenhof\'s reformed Esperanto, and likewise most rejected the recommendations of the 1907 Committee composed nominally of 12 members. Zamenhof, undoubtedly reminiscent of his experience of the 1894 reforms, strongly supported the Esperanto Committee majority decision. Furthermore, controversy ensued when the \"Ido project\" was found to have been devised mainly by Louis de Beaufront, whom Zamenhof had chosen to represent Esperanto to the committee (Zamenhof himself could not represent Esperanto as the committee\'s rules dictated that the creator of a submitted language could not defend it). The Committee\'s meetings were performed mainly in French, with occasional German. When the president of the Committee asked who was the author of Ido\'s project, Couturat, de Beaufront and Leau answered that they were not. De Beaufront presented Ido\'s project and gave a description of it as a better, richer version of Esperanto. Couturat, Leau, de Beaufront and Jespersen were finally the only members who voted, all of them for Ido\'s project. A month later, Couturat accidentally forwarded Jespersen a copy of a letter in which he acknowledged that de Beaufront was the author of the Ido project. Jespersen was angered by this and asked for a public confession. De Beaufront procrastinated for four months before making a public confession.
It is estimated that some 20% of Esperanto\'s major promoters and 3--4% of ordinary Esperantists switched to Ido, which from then on suffered constant modifications seeking to perfect it, but which ultimately had the effect of causing many Ido speakers to abandoned trying to learn it. Although it divided the Esperanto movement, the schism gave the remaining Esperantists the freedom to concentrate on using and promoting their language as it was. At the same time, it gave the Idists freedom to continue working on their own language for several more years before actively promoting it. The *Uniono di la Amiki di la Linguo Internaciona* (*Union of Friends of the International Language*) was established along with an Ido Academy to develop the details of the new language.
Couturat, who was the main proponent of Ido, was killed in an automobile accident in 1914. This, along with World War I, practically suspended the activities of the Ido Academy from 1914 to 1920. In 1928 Ido\'s major intellectual promoter, the Danish linguist Otto Jespersen, published his own planned language, Novial and ended his promotion of Ido.
### Digital era {#digital_era}
The language still has active speakers, numbering about 500. The Internet has caused a renewal of interest in the language during recent years. A sample of 24 Idists on the Yahoo! group *Idolisto* during November 2005 showed that 57% had begun their studies of the language during the preceding three years, 32% from the mid-1990s to 2002, and 8% had known the language from before.
| 776 |
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# Ido
## History
### Changes
Few changes have been made to Ido since 1922.
Camiel de Cock was named secretary of linguistic issues in 1990, succeeding Roger Moureaux. He resigned after the creation of a linguistic committee in 1991. De Cock was succeeded by Robert C. Carnaghan, who had the title from 1992 to 2008. No new words were adopted between 2001 and 2006. After the 2008--2011 elections of ULI\'s direction committee, Gonçalo Neves replaced Carnaghan as secretary of linguistic issues during February 2008. Neves resigned during August 2008. A new linguistic committee was formed in 2010. In April 2010, Tiberio Madonna was appointed as secretary of linguistic issues, succeeding Neves. In January 2011, ULI approved eight new words. This was the first addition of words in many years. After a series of severe conflicts with the Directing Committee of ULI, Tiberio Madonna was revoked as secretary of linguistic issues on the 26th of May 2013 by official announcement from Loïs Landais, the secretary of ULI. During January 2022, ULI approved a set of new words (34)
## Phonology
Ido has five vowel phonemes. The values `{{IPAblink|e|}}`{=mediawiki} and `{{IPAblink|ɛ||}}`{=mediawiki} are interchangeable depending on speaker preference, as are `{{IPAblink|o||}}`{=mediawiki} and `{{IPAblink|ɔ||}}`{=mediawiki}. The orthographic sequences `{{angbr|au}}`{=mediawiki} and `{{angbr|eu}}`{=mediawiki} indicate diphthongs in word roots but not when created by affixing.
\| Front \| Back
------- --------------------------------- ---------------------------------
Close
Mid \~ `{{IPA link|ɛ}}`{=mediawiki} \~ `{{IPA link|ɔ}}`{=mediawiki}
Open
: Ido vowels
+-------------+--------+---+---------------------------------+--------------------------------+----------------------------------+--------------------------------+
| | Labial | | Alveolar | | Post-\ | |
| | | | | | alveolar | |
+=============+========+===+=================================+================================+==================================+================================+
| Nasal | | | | | | |
+-------------+--------+---+---------------------------------+--------------------------------+----------------------------------+--------------------------------+
| Stop | | | | | | |
+-------------+--------+---+---------------------------------+--------------------------------+----------------------------------+--------------------------------+
| Affricate | | | c `{{IPAslink|t͡s}}`{=mediawiki} | | ch `{{IPAslink|t͡ʃ}}`{=mediawiki} | |
+-------------+--------+---+---------------------------------+--------------------------------+----------------------------------+--------------------------------+
| Fricative | | | | | sh `{{IPAslink|ʃ}}`{=mediawiki} | j `{{IPAslink|ʒ}}`{=mediawiki} |
+-------------+--------+---+---------------------------------+--------------------------------+----------------------------------+--------------------------------+
| Approximant | | | | | | |
+-------------+--------+---+---------------------------------+--------------------------------+----------------------------------+--------------------------------+
| Flap | | | | r `{{IPAslink|ɾ}}`{=mediawiki} | | |
+-------------+--------+---+---------------------------------+--------------------------------+----------------------------------+--------------------------------+
: Ido consonants
All polysyllabic words are stressed on the second-to-last syllable except for verb infinitives, which are stressed on the last syllable`{{spnd}}`{=mediawiki}**sko**lo, ka**fe**o and **ler**nas for \"school\", \"coffee\" and the present tense of \"to learn\", but i**rar**, sa**var** and drin**kar** for \"to go\", \"to know\" and \"to drink\". If an **i** or **u** precedes another vowel, the pair is considered part of the same syllable when applying the accent rule`{{spnd}}`{=mediawiki}thus **ra**dio, fa**mi**lio and **ma**nuo for \"radio\", \"family\" and \"hand\", unless the two vowels are the only ones in the word, in which case the \"i\" or \"u\" is stressed: **di**o, **fru**a for \"day\" and \"early\".
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# Ido
## Orthography
Ido uses the same 26 letters as the English alphabet and ISO Basic Latin alphabet with three digraphs and no ligatures or diacritics. Where the table below lists two pronunciations, either is perfectly acceptable.
Letter IPA English Esperanto
-------- --------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------- ------------
a *a* as in \"p**a**rt\"
b *b* as in \"sta**b**le\"
c most similar to *ts* as in \"ca**ts**\"`{{Break}}`{=mediawiki}\*(also used in the digraph *ch*)
d *d* as in \"a**d**opt\"
e , `{{IPAslink|ɛ}}`{=mediawiki} most similar to *e* as in \"**e**gg\" or *e* as in \"b**e**t\"
f *f* as in \"a**f**raid\"
g hard *g* as in \"**g**o\"
h *h* as in \"**h**at\", \"a**h**oy\"
i *i* as in \"mach**i**ne\", *ee* in \"b**ee**\"
j , `{{IPAslink|d͡ʒ}}`{=mediawiki} *s* as in \"plea**s**ure, mea**s**ure\" or *g* in \"mira**g**e, bei**g**e\" **ĵ or ĝ**
k *k* as in \"s**k**in, s**k**ip\"
l most similar to *l* as in \"**l**amb\"
m *m* as in \"ad**m**it\"
n *n* as in \"a**n**alogy\"
o , `{{IPAslink|ɔ}}`{=mediawiki} most similar to *o* as in \"**o**r\"
p *p* as in \"s**p**in, s**p**ark\"
q same as *k`{{Break}}`{=mediawiki}*\*(used only in the digraph *qu*) \-
r flapped or rolled *r* as in Italian or Spanish;`{{Break}}`{=mediawiki}or the *r* in ve**r**y in Scottish English pronunciation (cf *Pronunciation of English /r/*)
s *s* as in \"ea**s**t\"`{{Break}}`{=mediawiki}\*(also used in the digraph *sh*)
t *t* as in \"s**t**ake, s**t**op\"
u *u* as in \"r**u**de\"
v *v* as in \"a**v**oid\"
w *w* as in \"a**w**ard\" \-
x , `{{IPA|/ɡz/}}`{=mediawiki} x as in \"e**x**cept\" or \"e**x**ist\" \-
y *y* as in \"**y**es\" j
z *z* as in \"**z**ebra\"
The digraphs are:
Digraph IPA English Esperanto
--------- ------------------------------ -------------------------- -----------
ch *ch* as in \"**ch**ick\" **ĉ**
qu , `{{IPA|/kv/}}`{=mediawiki} *qu* as in \"**qu**ick\" \-
sh *sh* as in \"**sh**y\" **ŝ**
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# Ido
## Grammar
The definite article is *la* and is invariable. The indefinite article (a/an) does not exist in Ido. Each word in the Ido vocabulary is built from a root word. A word consists of a root and a grammatical ending. Other words can be formed from that word by removing the grammatical ending and adding a new one, or by inserting certain affixes between the root and the grammatical ending.
Some of the grammatical endings are defined as follows:
Grammatical form Ido Esperanto
-------------------------- ---------------- --------------------------------- --------------
Singular noun **-o** (libro) **-o** (libro)
Plural noun **-i** (libri) **-oj** (libroj)
Adjective **-a** (varma) **-a**, **-aj** (varma, varmaj)
Adverb **-e** (varme) **-e** (varme)
Present tense infinitive **-ar** (irar) **-anti** (iranti) **-i** (iri)
Past tense infinitive **-ir** (irir) **-inti** (irinti)
Future tense infinitive **-or** (iror) **-onti** (ironti)
Present **-as** (iras) **-as** (iras)
Past **-is** (iris) **-is** (iris)
Future **-os** (iros) **-os** (iros)
Imperative **-ez** (irez) **-u** (iru)
Conditional **-us** (irus) **-us** (irus)
These are the same as in Esperanto except for *-i*, *-ir*, *-ar*, *-or* and *-ez*. Esperanto marks noun plurals by an *agglutinative* ending *-j* (so plural nouns end in *-oj*), uses *-i* for verb infinitives (Esperanto infinitives are tenseless), and uses *-u* for the imperative. Verbs in Ido, as in Esperanto, do not conjugate depending on person, number or gender; the -**as**, -**is**, and -**os** endings suffice whether the subject is I, you, he, she, they, or anything else. For the word \"to be,\" Ido allows either *esas* or *es* in the present tense; however, the full forms must be used for the past tense *esis* and future tense *esos*.\" Adjectives and adverbs are compared in Ido by means of the words *plu* = more, *maxim* = most, *min* = less, *minim* = least, *kam* = than/as. There exist in Ido three categories of adverbs: the simple, the derived, and the composed. The simple adverbs do not need special endings, for example: *tre* = very, *tro* = too, *olim* = formerly, *nun* = now, *nur* = only. The derived and composed adverbs, not being originally adverbs but derived from nouns, adjectives and verbs, have the ending **-e**.
### Syntax
Ido word order is generally the same as English (subject--verb--object), so the sentence *Me havas la blua libro* is the same as the English \"I have the blue book\", both in meaning and word order. There are a few differences, however:
- Adjectives can precede the noun as in English, or follow the noun as in Spanish. Thus, *Me havas la libro blua* means the same thing.
- Ido has the accusative suffix *-n*. Unlike Esperanto, this suffix is only required when the object of the sentence is not clear, for example, when the subject-verb-object word order is not followed. Thus, *La blua libron me havas* also means the same thing.
Ido generally does not impose rules of grammatical agreement between grammatical categories within a sentence. For example, the verb in a sentence is invariable regardless of the number and person of the subject. Nor must the adjectives be pluralized as well the nouns`{{spnd}}`{=mediawiki}in Ido *the large books* would be *la granda libri* as opposed to the Esperanto *la grandaj libroj*.
Negation occurs in Ido by simply adding **ne** before a verb: **Me ne havas libro** means \"I do not have a book\". This as well does not vary, and thus the \"I do not\", \"He does not\", \"They do not\" before a verb are simply **Me ne**, **Il ne**, and **Li ne**. In the same way, past tense and future tense negatives are formed by **ne** before the conjugated verb. \"I will not go\" and \"I did not go\" become **Me ne iros** and **Me ne iris** respectively.
Yes/no questions are formed by the particle **ka** in front of the question. \"I have a book\" (me havas libro) becomes **Ka me havas libro?** (do I have a book?). **Ka** can also be placed in front of a noun without a verb to make a simple question, corresponding to the English \"is it?\" **Ka Mark?** can mean, \"Are you Mark?\", \"Is it Mark?\", \"Do you mean Mark?\" depending on the context.
### Pronouns
The pronouns of Ido were revised to make them more distinct acoustically than those of Esperanto, which all end in *i*. Especially the singular and plural first-person pronouns *mi* and *ni* may be difficult to distinguish in a noisy environment, so Ido has *me* and *ni* instead. Ido also distinguishes between intimate (*tu*) and formal (*vu*) second-person singular pronouns as well as plural second-person pronouns (*vi*) not marked for intimacy. Furthermore, Ido has a pan-gender third-person pronoun *lu* (it can mean \"he\", \"she\", or \"it\", depending on the context) in addition to its masculine (*il*), feminine (*el*), and neuter (*ol*) third-person pronouns.
singular
----------- ------------ ---------- --------- --------
first second third
*familiar* *formal* *masc.* *fem.*
Ido me tu vu il(u)
English I thou you he
Esperanto mi ci¹ vi¹ li
: Pronouns
1. *ci*, although technically the familiar form of the word \"you\" in Esperanto, is seldom used. Esperanto\'s inventor himself did not include the pronoun in the first book on Esperanto and only later reluctantly; later he recommended against using *ci* because different cultures have conflicting traditions regarding the use of the familiar and formal forms of \"you\".
2. *ri*, *iŝi*, *iĝi* and by extension *iri* are proposed neologisms and are rare, but they are still used albeit seldom.
*ol*, like English *it* and Esperanto *ĝi*, is not limited to inanimate objects, but can be used \"for entities whose sex is indeterminate: *babies, children, humans, youths, elders, people, individuals, horses, \[cattle\], cats,* etc.\"
*Lu* is often mistakenly labeled an epicene pronoun, that is, one that refers to both masculine and feminine beings, but in fact, *lu* is more properly a \"pan-gender\" pronoun, as it is also used for referring to inanimate objects. From *Kompleta Gramatiko Detaloza di la Linguo Internaciona Ido* by Beaufront:
### Table of correlatives {#table_of_correlatives}
Ido makes correlatives by combining entire words together and changing the word ending, with some irregularities to show distinction.
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| | | Relative and\ | Demonstrative | Indeterminate | Most\ | Negative |
| | | interrogative | | | Indeterminate | |
+=============+=============+===============+===============+=====================+===================+=======================+
| qua, ∅ | ita, ∅ | ula, ∅ | irga | nula | omna | |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Individual | -u | qua | ita ^1^ | ulu | irgu | nulu |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Plural | -i | qui | iti ^1^ | uli | irgi | nuli |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Thing | -o | quo | ito ^1^ | ulo | irgo | nulo |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Adjective | -a | qua | ita ^1^ | ula | irga | nula |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Motive | pro | pro quo | pro to | pro ulo | pro irgo | pro nulo |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Place | loke | ube | ibe | ulaloke | irgaloke | nulaloke |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Time | tempe | kande | lore | ulatempe ^2^ | irgatempe | nulatempe ^2^ |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Quality | -a, speca | quala | tala | ulaspeca ^2^ | irgaspeca | nulaspeca ^2^ |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Manner | -e, maniere | quale | tale | ule, ulamaniere ^2^ | irge, irgamaniere | nule, nulamaniere ^2^ |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Quantity -\ | quanta | quanta | tanta | kelka | irgaquanta | nulaquanta |
| adjective | | | | | | |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
| Quantity -\ | quanto | quanto | tanto | kelko | irga quanto ^4^ | nula quanto ^4^ |
| noun | | | | | | |
+-------------+-------------+---------------+---------------+---------------------+-------------------+-----------------------+
1. The initial *i* can be omitted: *ta*, *to*, *ti*, *ta*.
2. One can omit the initial *a*: *ultempe*, *nultempe*, *ulspeca*, *nulspeca*, *ulmaniere*, *nulmaniere*.
3. *omnatempe* is correct and usable, but *sempre* is the actual word.
4. Instead of *irga quanto*, *nula quanto* and *la tota quanto* one usually says *irgo*, *nulo* and *omno*.
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# Ido
## Grammar
### Compound formation {#compound_formation}
Composition in Ido obeys stricter rules than in Esperanto, especially formation of nouns, adjectives and verbs from a radical of a different class. The reversibility principle assumes that for each composition rule (affix addition), the corresponding decomposition rule (affix removal) is valid.
Hence, while in Esperanto an adjective (for instance *papera*), formed on the noun radical *paper(o)*, can mean an attribute (*papera enciklopedio* \"paper-made encyclopedia\") and a relation (*papera fabriko* \"paper-making factory\"), Ido will distinguish the attribute *papera* (\"paper\" or \"of paper\" (not \"paper-made\" exactly)) from the relation *paper\'\'\'al\'\'\'a* (\"paper-making\").
Similarly, *krono* means in both Esperanto and Ido the noun \"crown\"; where Esperanto allows formation of \"to crown\" by simply changing the ending from noun to verb *kroni* (\"crowning\" is *kronado*), Ido requires an affix so the composition is reversible: *kron\'\'\'iz\'\'\'ar* (\"the act of crowning\" is *kron\'\'\'iz\'\'\'o*).
According to Claude Piron, some modifications brought by Ido are in practice impossible to use and ruin spontaneous expression:
> Ido displays, on linguistic level, other drawbacks Esperanto succeeded to avoid, but I don\'t have at hand documents which would allow me to go further in detail. For instance, if I remember correctly, where Esperanto only has the suffix *-igi*\*, Ido has several: \**-ifar*\*, \**-izar*\*, \**-igar*\*, which match subtleties which were meant to make language clearer, but that, in practice, inhibit natural expression.
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# Ido
## Vocabulary
Vocabulary in Ido is derived from French, Italian, Spanish, English, German, and Russian. Basing the vocabulary on various widespread languages was intended to make Ido as easy as possible for the greatest number of people possible. Early on, the first 5,371 Ido word roots were analyzed compared to the vocabulary of the six source languages, and the following result was found:
- 2024 roots (38%) belong to 6 languages
- 942 roots (17%) belong to 5 languages
- 1111 roots (21%) belong to 4 languages
- 585 roots (11%) belong to 3 languages
- 454 roots (8%) belong to 2 languages
- 255 roots (5%) belong to 1 language
Another analysis showed that:
- 4880 roots (91%) are found in French
- 4454 roots (83%) are found in Italian
- 4237 roots (79%) are found in Spanish
- 4219 roots (79%) are found in English
- 3302 roots (61%) are found in German
- 2821 roots (52%) are found in Russian
Ido French Italian Spanish English
--------- --------- ---------- -------- ---------- ------- ---------
bona bon buono bueno good
donar donner dare donare dar donar give
filtrar filtrer filtrare filtrar filter
gardeno jardin giardino jardín garden
kavalo cheval cavallo caballo horse
maro mer mare mar sea
naciono nation nazione nación nation
studiar étudier studiare estudiar study
yuna jeune giovane joven young
: Comparison of Ido vocabulary with its six source languages (by \# of roots)
Ido Esperanto Latin Germanic
--------- ----------- ----------------- ----------
bona bona bonum
donar doni dare
filtrar filtri spargere felt
gardeno ĝardeno hortum gardo
kavalo ĉevalo equum, caballus
maro maro mare
naciono nacio gentem, natio
studiar studi studere
yuna juna iuvenis jung
: Comparison of Ido vocabulary with Esperanto and Latin (or Germanic root)
Vocabulary in Ido is often created through a number of official prefixes and suffixes that alter the meaning of the word. This allows a user to take existing words and modify them to create neologisms when necessary, and allows for a wide range of expression without the need to learn new vocabulary each time. Though their number is too large to be included in one article, some examples include:
- The diminutive suffix **-et-**. **Domo** (house) becomes **dometo** (cottage), and **libro** (book) becomes **libreto** (novelette or short story).
- The pejorative suffix **-ach-**. **Domo** becomes **domacho** (hovel), and **libro** becomes **libracho** (a shoddy piece of work, pulp fiction, etc.)
- The prefix **retro-**, which implies a reversal. **Irar** (to go) becomes **retroirar** (to go back, backward) and **venar** (to come) becomes **retrovenar** (to return).
New vocabulary is generally created through an analysis of the word, its etymology, and reference to the six source languages. If a word can be created through vocabulary already existing in the language then it will usually be adopted without need for a new radical (such as **wikipedio** for *Wikipedia*, which consists of **wiki** + **enciklopedio** for *encyclopedia*), and if not then an entirely new word will be created. The word **alternatoro** for example was adopted in 1926, likely because five of the six source languages used largely the same orthography for the word, and because it was long enough to avoid being mistaken for other words in the existing vocabulary. Adoption of a word is done through consensus, after which the word will be made official by the union. Care must also be taken to avoid homonyms if possible, and usually a new word undergoes some discussion before being adopted. Foreign words that have a restricted sense and are not likely to be used in everyday life (such as the word *intifada* to refer to the conflict between Israel and Palestine) are left untouched, and often written in italics.
Ido, unlike Esperanto, does not assume the male sex by default. For example, Ido does not derive the word for \"waitress\" by adding a feminine suffix to \"waiter\", as Esperanto does. Instead, Ido words are defined as sex-neutral, and two different suffixes derive masculine and feminine words from the root: **servisto** for a waiter of either sex, **servistulo** for a male waiter, and **servistino** for a waitress. There are only two exceptions to this rule: First, **patro** for \"father\", **matro** for \"mother\", and **genitoro** for \"parent\", and second, **viro** for \"man\", **muliero** for \"woman\", and **adulto** for \"adult\".
| 712 |
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| 6 |
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# Ido
## Sample
The Lord\'s Prayer:
+--------------------------------------------+---------------------------------------------+
| **Ido** Patro nia, qua esas en la cielo,\ | **English** Our Father, who art in heaven,\ |
| tua nomo santigesez;\ | hallowed be your name.\ |
| tua regno advenez;\ | Thy kingdom come,\ |
| tua volo facesez\ | Thy will be done,\ |
| quale en la cielo, tale anke sur la tero.\ | on earth as it is in heaven.\ |
| Donez a ni cadie l\'omnadia pano,\ | Give us this day our daily bread,\ |
| e pardonez a ni nia ofensi,\ | and forgive us our debts,\ |
| quale anke ni pardonas a nia ofensanti,\ | as we also have forgiven our debtors.\ |
| e ne duktez ni aden la tento,\ | And lead us not into temptation,\ |
| ma liberigez ni del malajo.\ | but deliver us from evil.\ |
+--------------------------------------------+---------------------------------------------+
## Literature and publications {#literature_and_publications}
Ido has a number of publications that can be subscribed to or downloaded for free in most cases. *Kuriero Internaciona* is a magazine produced in France every few months with a range of topics. *Adavane!* is a magazine produced by the Spanish Ido Society every two months that has a range of topics, as well as a few dozen pages of work translated from other languages. *Progreso* is the official organ for the language and has existed since the ibeginning of Idoism in 1908. Other sites can be found with various stories, fables or proverbs along with a few books of the Bible translated into Ido on a smaller scale. The site *publikaji* has a few podcasts in Ido along with various songs and other recorded material.
Wikipedia includes an [Ido-language edition](http://io.wikipedia.org/) (known in Ido as *Wikipedio*); in 2018 it was the 93rd most visited Wikipedia, and is second most viewed Wikipedia edition in artificial language (after Esperanto).
## Symbols of Ido {#symbols_of_ido}
The Ido star or Jankó star is the main symbol of Ido. It is a six pointed star, with the points representing Ido\'s six source languages: English, French, Italian, German, Spanish and Russian. Alternatively, the six points represent the six continents (excluding Antarctica). The emblem was originally a six pointed white star on a circular blue background, consisting of two concentric, equilateral triangles, with one vertically flipped. However, this was soon changed due to the similarity it presented with the Star of David, since a true international auxiliary language should not have religious affiliations.
After a search to find an appropriate new symbol, the Ido-Akademio decided on the current Ido symbol, created by their secretary, Paul von Jankó (hence the alternative name the Jankó star). The current Ido Star is a concave isotoxal hexagon, with a vertically flipped equilateral triangle overlaid on top.
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# Ido
## International Ido conventions {#international_ido_conventions}
ULI organises Ido conventions yearly, and the conventions include a mix of tourism and work. `{{div col|colwidth=15em}}`{=mediawiki}
- 2024: Madrid, Spain ([1](https://www.idohispania.com))
- 2023: Kassel, Germany ([2](http://www.ido.li/index.php/ULI/Idorenkontro2023))
- 2022: Dessau, Germany, 15 participants([3](http://www.ido.li/index.php/ULI/Idorenkontro2022))
- 2019: Berlin, Germany, 15 participants from 2 countries ([Information](http://www.ido.li/index.php/ULI/Idorenkontro2019))
- 2018: Provins, France, 11 participants from 5 countries ([Information](http://www.ido.li/index.php/ULI/Idorenkontro2018))
- 2017: České Budějovice, Czech Republic, 8 participants from 5 countries ([Information](http://www.ido.li/index.php/ULI/Idorenkontro2017))
- 2016: Valencia, Spain, 10 participants from 7 countries ([Information](https://web.archive.org/web/20160412101145/http://www.uli-ido.ovh/ULI/index.php?page=internaciona-renkontro-2016))
- 2015: Berlin, Germany, 14 participants ([Information](http://www.ido.li/index.php/ULI/IR2015))
- 2014: Paris, France ([Information](http://www.ido.li/index.php/ULI/Paris2014))
- 2013: Ouroux-en-Morvan, France, 13 participants from 4 countries ([Information](http://www.ido.li/index.php/ULI/Ouroux2013))
- 2012: Dessau, Germany, 12 participants ([Information](http://www.ido.li/index.php/ULI/Dessau2012))
- 2011: Echternach, Luxembourg ([Information](http://www.ido.li/index.php/ULI/IR2011)), 24 participants from 11 countries
- 2010: Tübingen, Germany ([Information](http://www.ido.li/index.php/ULI/IR2010))
- 2009: Riga, Latvia, and Tallinn, Estonia, 14 participants from 7 countries ([Information](http://www.ido.li/index.php/ULI/Tallin2009))
- 2008: Wuppertal-Neviges, Germany, 18 participants from 5 countries ([Information](http://www.idolinguo.de/Idorenkontro2008/))
- 2007: Paris, France, 14 participants from 9 countries ([Information](http://www.ido.li/Idorenkontro2007/), [Photos](https://plus.google.com/photos/117431545220080970838/albums/5131141749857219169))
- 2006: Berlin, Germany, approx. 25 participants from 10 countries ([Information](http://www.idolinguo.de/index.php/DIG/IdoKonfereo2006))
- 2005: Toulouse, France, 13 participants from 4 countries ([Information](http://www.europa.idolinguo.com/Francia/Idorenkontro2005/))
- 2004: Kyiv, Ukraine, 17 participants from 9 countries ([Information](http://www.europa.idolinguo.com/Ukrainia/Idorenkontro2004/))
- 2003: Großbothen, Germany, participants from 6 countries ([Information](http://www.europa.idolinguo.com/Germania/Idokonfero2003/ido.htm))
- 2002: Kraków, Poland, 14 participants from 6 countries ([Information](http://www.europa.idolinguo.com/Polonia/krakow2002.htm))
- 2001: Nuremberg, Germany, 14 participants from 5 countries ([Information](http://www.nefkom.net/frank.kasper/konf2001.htm))
- 2000: Nuremberg, Germany
- 1999: Waldkappel, Germany
- 1998: Białobrzegi, Poland, 15 participants from 6 countries
- 1997: Bakkum, Netherlands, 19 participants from 7 countries
- 1995: Elsnigk, Germany
- 1991: Ostend, Belgium, 21 participants
- 1990: Waldkappel, Germany
- 1989: Zürich-Thalwil, Switzerland
- 1987: Eschwege, Germany
- 1985: Antwerp, Belgium
- 1983: York, England
- 1981: Jongny, Switzerland
- 1980: Namur, Belgium, 35 participants
- 1979: Uppsala, Sweden
- 1978: Cambridge, England
- 1977: Berlin-Tegel, Germany
- 1976: Saint-Nazaire, France
- 1975: Thun, Switzerland
- 1974: Kyiv, Ukraine
- 1973: Cardiff, Wales
- 1972: Chaux-de-Fonds, Switzerland
- 1971: Trollhättan, Sweden
- 1970: Luxembourg City, Luxembourg
- 1969: Zürich, Switzerland
- 1968: Berlin, Germany
- 1967: Bourges, France
- 1966: Biella, Italy
- 1965: Lons-le-Saunier, France
- 1964: Kiel, Germany
- 1963: Barcelona, Spain
- 1962: Thun, Switzerland
- 1961: Zürich, Switzerland, c. 50 participants
- 1960: Colmar, France
- 1959: Freiburg im Breisgau, Germany
- 1957: Luxembourg City, Luxembourg
- 1952: Berlin, Germany
- 1951: Turin, Italy
- 1950: Colmar, France
- 1939: St
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# Cosmicomics
***Cosmicomics*** (*Le cosmicomiche*) is a collection of twelve short stories by Italo Calvino first published in Italian in 1965 and in English in 1968. The stories were originally published between 1964 and 1965 in the Italian periodicals *Il Caffè* and *Il Giorno*. Each story takes a scientific theory (some of which have since become deprecated) or phenomenon and builds an imaginative story around it. An always-extant being called Qfwfq explicitly narrates all of the stories save two. Every story is a memory of an event in the history of the universe.
All of the stories in *Cosmicomics*, together with more of Qfwfq stories from *t zero* and other sources, are now available in a single volume collection, *The Complete Cosmicomics* (Penguin UK, 2009).
The first U.S. edition, translated by William Weaver, won the National Book Award in the Translation category.
## Contents
- \"The Distance of the Moon\", the first and probably the best known story. Calvino takes the fact that the Moon used to be much closer to the Earth, and builds a story about a love triangle among people who used to jump between the Earth and the Moon; the lovers gradually drift apart as the Moon recedes.
- \"At Daybreak\": Life in a nebula before gas condenses into solid matter, a process which ultimately leads to the formation of solar systems.
- \"A Sign in Space\": The fact that the galaxy slowly revolves is the premise of a story about a being desperate to leave behind some unique sign of its existence. This story is a direct illustration of one of the tenets of postmodern theory---that the sign is not the thing it signifies, nor can one claim to fully or properly describe a thing or an idea with a word or other symbol.
- \"All at One Point\": The fact that before the Big Bang the cosmos existed as a single point (the initial singularity. \"Naturally, we were all there---old Qfwfq said---where else could we have been? Nobody knew then that there could be space. Or time, either: what use did we have for time, packed in there like sardines?\"
- \"Without Colors\": Before there was an atmosphere, everything was the same shade of gray. As the atmosphere gradually appears, so do colors. Unfortunately the novelty scares off Ayl, Qfwfq\'s love interest.
- \"Games Without End\": A galactic game of marbles played using Hydrogen atoms, before the universe had created other materials.
- \"The Aquatic Uncle\": A tale on the fact that at one stage in evolution animals left the sea and came to live on land. The story is about a family living on land that is a bit ashamed of their old uncle who still lives in the sea, refusing to come ashore like \"civilized\" people.
- \"How Much Shall We Bet\": Qfwfq bets against his rival Dean (k)yK about the universe\'s transformations, making increasingly long-term and specific conjectures.
- \"The Dinosaurs\": How some dinosaurs lived after most of them had become extinct, and how it felt to be that last existing dinosaur in an age where all the current mammals feared his kind as demons.
- \"The Form of Space\": As the unnamed narrator \"falls\" through space, he cannot help but notice that his trajectory is parallel to that of a beautiful woman, Ursula H\'x, and that of lieutenant Fenimore, who is also in love with Ursula. The narrator dreams of the shape of space changing, so that he may touch Ursula (or fight with Fenimore).
- \"The Light Years\": The unnamed narrator looking at other galaxies spots one with a sign pointed right at him saying \"I saw you.\" Given that there\'s a gulf of 100,000,000 light years, he checks his diary to find out what he had been doing that day eons ago, and finds out that it was something he had wished to hide. He then starts to worry.
- \"The Spiral\": A story about life as a mollusc who creates the first shell. By creating this object of beauty to behold, he enables the development of vision in other creatures and sets off a chain reaction leading to the present day.
All of the stories feature non-human characters who have been heavily anthropomorphized.
## Adaptations
*\"La Luna\" by Enrico Casarosa, 2011* is a short film based on the same premise as \"The Distance of the Moon
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# IA-32
**IA-32** (short for \"**Intel Architecture, 32-bit**\", commonly called *i386*) is the 32-bit version of the x86 instruction set architecture, designed by Intel and first implemented in the 80386 microprocessor in 1985. IA-32 is the first incarnation of x86 that supports 32-bit computing; as a result, the \"IA-32\" term may be used as a metonym to refer to all x86 versions that support 32-bit computing.
Within various programming language directives, IA-32 is still sometimes referred to as the \"i386\" architecture. In some other contexts, certain iterations of the IA-32 ISA are sometimes labelled *i486*, *i586* and *i686*, referring to the instruction supersets offered by the 80486, the P5 and the P6 microarchitectures respectively. These updates offered numerous additions alongside the base IA-32 set including floating-point capabilities and the MMX extensions.
Intel was historically the largest manufacturer of IA-32 processors, with the second biggest supplier having been AMD. During the 1990s, VIA, Transmeta and other chip manufacturers also produced IA-32 compatible processors (e.g. WinChip). In the modern era, Intel still produced IA-32 processors under the Intel Quark microcontroller platform until 2019; however, since the 2000s, the majority of manufacturers (Intel included) moved almost exclusively to implementing CPUs based on the 64-bit variant of x86, x86-64. x86-64, by specification, offers legacy operating modes that operate on the IA-32 ISA for backwards compatibility. Even given the contemporary prevalence of x86-64, as of today, IA-32 protected mode versions of many modern operating systems are still maintained, e.g. Microsoft Windows (until Windows 10), Windows Server (until Windows Server 2008) and the Debian Linux distribution. In spite of IA-32\'s name (and causing some potential confusion), the 64-bit evolution of x86 that originated out of AMD would not be known as \"IA-64\", that name instead belonging to Intel\'s discontinued Itanium architecture.
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# IA-32
## Architectural features {#architectural_features}
The primary defining characteristic of IA-32 is the availability of 32-bit general-purpose processor registers (for example, EAX and EBX), 32-bit integer arithmetic and logical operations, 32-bit offsets within a segment in protected mode, and the translation of segmented addresses to 32-bit linear addresses. The designers took the opportunity to make other improvements as well. Some of the most significant changes (relative to the 16-bit 286 instruction set) are:
32-bit integer capability: All general-purpose registers (GPRs) are expanded from 16 bits to 32 bits, and all arithmetic and logical operations, memory-to-register and register-to-memory operations, etc., can operate directly on 32-bit integers. Pushes and pops on the stack default to 4-byte strides, and non-segmented pointers are 4 bytes wide.\
More general addressing modes: Any GPR can be used as a base register, and any GPR other than ESP can be used as an index register, in a memory reference. The index register value can be multiplied by 1, 2, 4, or 8 before being added to the base register value and displacement.\
Additional segment registers: Two additional segment registers, FS and GS, are provided.\
Larger virtual address space: The IA-32 architecture defines a 48-bit segmented address format, with a 16-bit segment number and a 32-bit offset within the segment. Segmented addresses are mapped to 32-bit linear addresses.\
Demand paging: 32-bit linear addresses are virtual addresses rather than physical addresses; they are translated to physical addresses through a page table. In the 80386, 80486, and the original Pentium processors, the physical address was 32 bits; in the Pentium Pro and later processors, the Physical Address Extension allowed 36-bit physical addresses, although the linear address size was still 32 bits
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# Internalism and externalism
**Internalism** and **externalism** are two opposite ways of integrating and explaining various subjects in several areas of philosophy. These include human motivation, knowledge, justification, meaning, and truth. The distinction arises in many areas of debate with similar but distinct meanings. Internal--external distinction is a distinction used in philosophy to divide an ontology into two parts: an internal part concerning observation related to philosophy, and an external part concerning question related to philosophy.
Internalism is the thesis that no fact about the world can provide reasons for action independently of desires and beliefs. Externalism is the thesis that reasons are to be identified with objective features of the world.
## Moral philosophy {#moral_philosophy}
### Motivation
In contemporary moral philosophy, **motivational internalism** (or **moral internalism** ) is the view that moral convictions (which are not necessarily beliefs, e.g. feelings of moral approval or disapproval) are intrinsically motivating. That is, the motivational internalist believes that there is an internal, necessary connection between one\'s conviction that X ought to be done and one\'s motivation to do X. Conversely, the **motivational externalist** (or **moral externalist** ) claims that there is no necessary internal connection between moral convictions and moral motives. That is, there is no necessary connection between the conviction that X is wrong and the motivational drive not to do X. (The use of these terms has roots in W.D. Falk\'s (1947) paper \"\'Ought\' and Motivation\".)
These views in moral psychology have various implications. In particular, if motivational internalism is true, then amorality is unintelligible (and metaphysically impossible). An amoralist is not simply someone who is immoral, rather it is someone who knows what the moral things to do are, yet is not motivated to do them. Such an agent is unintelligible to the motivational internalist, because moral judgments about the right thing to do have built into them corresponding motivations to do those things that are judged by the agent to be the moral things to do. On the other hand, an amoralist is entirely intelligible to the motivational *externalist*, because the motivational externalist thinks that moral judgments about what is right do not necessitate some motivation to do those things that are judged to be the right thing to do; rather, an independent desire---such as the desire to do the right thing---is required (Brink, 2003), (Rosati, 2006).
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# Internalism and externalism
## Moral philosophy {#moral_philosophy}
### Reasons
There is also a distinction in ethics and action theory, largely made popular by Bernard Williams (1979, reprinted in 1981), concerning internal and external reasons for an action. An *internal reason* is, roughly, something that one has in light of one\'s own \"subjective motivational set\"---one\'s own commitments, desires (or wants), goals, etc. On the other hand, an *external reason* is something that one has independent of one\'s subjective motivational set. For example, suppose that Sally is going to drink a glass of poison, because she wants to commit suicide and believes that she can do so by drinking the poison. Sally has an internal reason to drink the poison, because she wants to commit suicide. However, one might say that she has an external reason not to drink the poison because, even though she wants to die, one ought not to kill oneself no matter what---regardless of whether one wants to die.
Some philosophers embrace the existence of both kinds of reason, while others deny the existence of one or the other. For example, Bernard Williams (1981) argues that there are really only internal reasons for action. Such a view is called *internalism about reasons* (or *reasons internalism*). *Externalism about reasons* (or *reasons externalism*) is the denial of reasons internalism. It is the view that there are external reasons for action; that is, there are reasons for action that one can have even if the action is not part of one\'s subjective motivational set.
Consider the following situation. Suppose that it\'s against the moral law to steal from the poor, and Sasha knows this. However, Sasha doesn\'t desire to follow the moral law, and there is currently a poor person next to him. Is it intelligible to say that Sasha has a reason to follow the moral law right now (to not steal from the poor person next to him), even though he doesn\'t care to do so? The reasons externalist answers in the affirmative (\"Yes, Sasha has a reason not to steal from that poor person.\"), since he believes that one can have reasons for action even if one does not have the relevant desire. Conversely, the reasons internalist answers the question in the negative (\"No, Sasha does not have a reason not to steal from that poor person, though others might.\"). The reasons internalist claims that external reasons are unintelligible; one has a reason for action only if one has the relevant desire (that is, only internal reasons can be reasons for action). The reasons internalist claims the following: the moral facts are a reason *for Sasha\'s action* not to steal from the poor person next to him only if he currently *wants* to follow the moral law (or if not stealing from the poor person is a way to satisfy his other current goals---that is, part of what Williams calls his \"subjective motivational set\"). In short, the reasoning behind reasons internalism, according to Williams, is that reasons for action must be able to explain one\'s action; and only internal reasons can do this.
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# Internalism and externalism
## Epistemology
### Justification
#### Internalism
Two main varieties of epistemic internalism about justification are access internalism and ontological internalism. Access internalists require that a believer must have internal access to the justifier(s) of their belief *p* in order to be justified in believing *p*. For the access internalist, justification amounts to something like the believer being aware (or capable of being aware) of certain facts that make her belief in *p* rational, or them being able to give reasons for her belief in *p*. At minimum, access internalism requires that the believer have some kind of reflective access or awareness to whatever justifies her belief. Ontological internalism is the view that justification for a belief is established by one\'s mental states. Ontological internalism can be distinct from access internalism, but the two are often thought to go together since we are generally considered to be capable of having reflective access to mental states.
One popular argument for internalism is known as the \'new evil demon problem\'. The new evil demon problem indirectly supports internalism by challenging externalist views of justification, particularly reliabilism. The argument asks us to imagine a subject with beliefs and experiences identical to ours, but the subject is being systematically deceived by a malicious Cartesian demon so that all their beliefs turn out false. In spite of the subject\'s unfortunate deception, the argument goes, we do not think this subject ceases to be rational in taking things to be as they appear as we do. After all, it is possible that we could be radically deceived in the same way, yet we are still justified in holding most of our beliefs in spite of this possibility. Since reliabilism maintains that one\'s beliefs are justified via reliable belief-forming processes (where reliable means yielding true beliefs), the subject in the evil demon scenario would not likely have any justified beliefs according to reliabilism because all of their beliefs would be false. Since this result is supposed to clash with our intuitions that the subject is justified in their beliefs in spite of being systematically deceived, some take the new evil demon problem as a reason for rejecting externalist views of justification.
#### Externalism
Externalist views of justification emerged in epistemology during the late 20th century. Externalist conceptions of justification assert that facts external to the believer can serve as the justification for a belief. According to the externalist, a believer need not have any internal access or cognitive grasp of any reasons or facts which make their belief justified. The externalist\'s assessment of justification can be contrasted with access internalism, which demands that the believer have internal reflective access to reasons or facts which corroborate their belief in order to be justified in holding it. Externalism, on the other hand, maintains that the justification for someone\'s belief can come from facts that are entirely external to the agent\'s subjective awareness.
Alvin Goldman, one of the most well-known proponents of externalism in epistemology, is known for developing a popular form of externalism called reliabilism. In his paper, "What is Justified Belief?" Goldman characterizes the reliabilist conception of justification as such:
\"If S's believing *p* at *t* results from a reliable cognitive belief-forming process (or set of processes), then S's belief in *p* at *t* is justified."
Goldman notes that a reliable belief-forming process is one which generally produces true beliefs.
A unique consequence of reliabilism (and other forms of externalism) is that one can have a justified belief without knowing one is justified (this is not possible under most forms of epistemic internalism). In addition, we do not yet know which cognitive processes are in fact reliable, so anyone who embraces reliabilism must concede that we do not always know whether some of our beliefs are justified (even though there is a fact of the matter).
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# Internalism and externalism
## Epistemology
### As a response to skepticism {#as_a_response_to_skepticism}
In responding to skepticism, Hilary Putnam (1982) claims that semantic externalism yields \"an argument we can give that shows we are not brains in a vat (BIV). (See also DeRose, 1999.) If semantic externalism is true, then the meaning of a word or sentence is not wholly determined by what individuals think those words mean. For example, semantic externalists maintain that the word \"water\" referred to the substance whose chemical composition is H~2~O even before scientists had discovered that chemical composition. The fact that the substance out in the world we were calling \"water\" actually had that composition at least partially determined the meaning of the word. One way to use this in a response to skepticism is to apply the same strategy to the terms used in a skeptical argument in the following way (DeRose, 1999):
To clarify how this argument is supposed to work: Imagine that there is brain in a vat, and a whole world is being simulated for it. Call the individual who is being deceived \"Steve.\" When Steve is given an experience of walking through a park, semantic externalism allows for his thought, \"I am walking through a park\" to be true so long as the simulated reality is one in which he is walking through a park. Similarly, what it takes for his thought, \"I am a brain in a vat,\" to be true is for the simulated reality to be one where he is a brain in a vat. But in the simulated reality, he is not a brain in a vat.
Apart from disputes over the success of the argument or the plausibility of the specific type of semantic externalism required for it to work, there is question as to what is gained by defeating the skeptical worry with this strategy. Skeptics can give new skeptical cases that wouldn\'t be subject to the same response (e.g., one where the person was very recently turned into a brain in a vat, so that their words \"brain\" and \"vat\" still pick out real brains and vats, rather than simulated ones). Further, if even brains in vats can correctly believe \"I am not a brain in a vat,\" then the skeptic can still press us on how we know we are not in that situation (though the externalist will point out that it may be difficult for the skeptic to describe that situation).
Another attempt to use externalism to refute skepticism is done by Brueckner and Warfield. It involves the claim that our thoughts are *about* things, unlike a BIV\'s thoughts, which cannot be *about* things (DeRose, 1999).
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# Internalism and externalism
## Semantics
Semantic externalism comes in two varieties, depending on whether meaning is construed cognitively or linguistically. On a cognitive construal, externalism is the thesis that what concepts (or contents) are available to a thinker is determined by their environment, or their relation to their environment. On a linguistic construal, externalism is the thesis that the meaning of a word is environmentally determined. Likewise, one can construe semantic internalism in two ways, as a denial of either of these two theses.
Externalism and internalism in semantics is closely tied to the distinction in philosophy of mind concerning mental content, since the contents of one\'s thoughts (specifically, intentional mental states) are usually taken to be semantic objects that are truth-evaluable.
See also:
- Linguistic turn for more about the two construals of meaning
- Swamp man thought experiment
- Twin Earth thought experiment
## Philosophy of mind {#philosophy_of_mind}
Within the context of the philosophy of mind, externalism is the theory that the contents of at least some of one\'s mental states are dependent in part on their relationship to the external world or one\'s environment.
The traditional discussion on externalism was centered around the semantic aspect of mental content. This is by no means the only meaning of externalism now. Externalism is now a broad collection of philosophical views considering all aspects of mental content and activity. There are various forms of externalism that consider either the content or the vehicles of the mind or both. Furthermore, externalism could be limited to cognition, or it could address broader issues of consciousness.
As to the traditional discussion on semantic externalism (often dubbed *content externalism*), some mental states, such as believing that water is wet, and fearing that the Queen has been insulted, have contents we can capture using \'that\' clauses. The content externalist often appeal to observations found as early as Hilary Putnam\'s seminal essay, \"The Meaning of \'Meaning\',\" (1975). Putnam stated that we can easily imagine pairs of individuals that are microphysical duplicates embedded in different surroundings who use the same words but mean different things when using them.
For example, suppose that Ike and Tina\'s mothers are identical twins and that Ike and Tina are raised in isolation from one another in indistinguishable environments. When Ike says, \"I want my mommy,\" he expresses a want satisfied only if he is brought to his mommy. If we brought Tina\'s mommy, Ike might not notice the difference, but he doesn\'t get what he wants. It seems that what he wants and what he says when he says, \"I want my mommy,\" will be different from what Tina wants and what she says she wants when she says, \"I want my mommy.\"
Externalists say that if we assume competent speakers know what they think, and say what they think, the difference in what these two speakers mean corresponds to a difference in the thoughts of the two speakers that is not (necessarily) reflected by a difference in the internal make up of the speakers or thinkers. They urge us to move from externalism about meaning of the sort Putnam defended to externalism about contentful states of mind. The example pertains to singular terms, but has been extended to cover kind terms as well such as natural kinds (e.g., \'water\') and for kinds of artifacts (e.g., \'espresso maker\'). There is no general agreement amongst content externalists as to the scope of the thesis.
Philosophers now tend to distinguish between *wide content* (externalist mental content) and *narrow content* (anti-externalist mental content). Some, then, align themselves as endorsing one view of content exclusively, or both. For example, Jerry Fodor (1980) argues for narrow content (although he comes to reject that view in his 1995), while David Chalmers (2002) argues for a two dimensional semantics according to which the contents of mental states can have both wide and narrow content.
Critics of the view have questioned the original thought experiments saying that the lessons that Putnam and later writers such as Tyler Burge (1979, 1982) have urged us to draw can be resisted. Frank Jackson and John Searle, for example, have defended internalist accounts of thought content according to which the contents of our thoughts are fixed by descriptions that pick out the individuals and kinds that our thoughts intuitively pertain to the sorts of things that we take them to. In the Ike/Tina example, one might agree that Ike\'s thoughts pertain to Ike\'s mother and that Tina\'s thoughts pertain to Tina\'s but insist that this is because Ike thinks of that woman as his mother and we can capture this by saying that he thinks of her as \'the mother of the speaker\'. This descriptive phrase will pick out one unique woman. Externalists claim this is implausible, as we would have to ascribe to Ike knowledge he wouldn\'t need to successfully think about or refer to his mother.
Critics have also claimed that content externalists are committed to epistemological absurdities. Suppose that a speaker can have the concept of water we do only if the speaker lives in a world that contains H~2~O. It seems this speaker could know a priori that they think that water is wet. This is the thesis of privileged access. It also seems that they could know on the basis of simple thought experiments that they can only think that water is wet if they live in a world that contains water. What would prevent her from putting these together and coming to know a priori that the world contains water? If we should say that no one could possibly know whether water exists a priori, it seems either we cannot know content externalism to be true on the basis of thought experiments or we cannot know what we are thinking without first looking into the world to see what it is like.
As mentioned, content externalism (limited to the semantic aspects) is only one among many other options offered by externalism by and large.
See also:
- Twin Earth thought experiment
- Extended cognition
## Historiography of science {#historiography_of_science}
**Internalism in the historiography of science** claims that science is completely distinct from social influences and pure natural science can exist in any society and at any time given the intellectual capacity. Imre Lakatos is a notable proponent of historiographical internalism.
**Externalism in the historiography of science** is the view that the history of science is due to its social context -- the socio-political climate and the surrounding economy determines scientific progress. Thomas Kuhn is a notable proponent of historiographical externalism
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# Isolationism
**Isolationism** is a term used to refer to a political philosophy advocating a foreign policy that opposes involvement in the political affairs, and especially the wars, of other countries. Thus, isolationism fundamentally advocates neutrality and opposes entanglement in military alliances and mutual defense pacts. In its purest form, isolationism opposes all commitments to foreign countries, including treaties and trade agreements. In the political science lexicon, there is also the term of \"non-interventionism\", which is sometimes improperly used to replace the concept of \"isolationism\". \"Non-interventionism\" is commonly understood as \"a foreign policy of political or military non-involvement in foreign relations or in other countries\' internal affairs\". \"Isolationism\" should be interpreted more broadly as \"a foreign policy grand strategy of military and political non-interference in international affairs and in the internal affairs of sovereign states, associated with trade and economic protectionism and cultural and religious isolation, as well as with the inability to be in permanent military alliances, with the preservation, however, some opportunities to participate in temporary military alliances that meet the current interests of the state and in permanent international organizations of a non-military nature.\"
This contrasts with philosophies such as colonialism, expansionism, and liberal internationalism.
## Introduction
Isolationism has been defined as:
## By country {#by_country}
### Albania
### Bhutan
Before 1999, Bhutan had banned television and the Internet in order to preserve its culture, environment, and identity. Eventually, Jigme Singye Wangchuck lifted the ban on television and the Internet. His son, Jigme Khesar Namgyel Wangchuck, was elected Druk Gyalpo of Bhutan, which helped forge the Bhutanese democracy. Bhutan has subsequently undergone a transition from an absolute monarchy to a constitutional monarchy multi-party democracy. The development of *Bhutanese democracy* has been marked by the active encouragement and participation of the reigning Bhutanese monarchs since the 1950s, beginning with legal reforms, and culminating in the enactment of Bhutan\'s Constitution.
Tourism in Bhutan was prohibited until 1974. Since then, the country has allowed foreigners to visit, but has tightly controlled tourism in an effort to preserve its natural and cultural heritage. `{{As of|2022|post=,}}`{=mediawiki} tourists must pay a \$200 per day fee on top of other travel expenses such as meals and accommodation. Prior to 2022, visitors were not allowed to travel independently and had to be accompanied by a tour guide. `{{as of|2021|post=,}}`{=mediawiki} Bhutan does not maintain formal foreign relations with any of the five permanent members of the UN Security Council, notably including China, its neighbor to the north with which it has a historically tense relationship.
### Cambodia
From 1431 to 1863, the Kingdom of Cambodia enforced an isolationist policy. The policy prohibited foreign contact with most outside countries. When Pol Pot and the Khmer Rouge came to power on 17 April 1975 and established Democratic Kampuchea, the urban population of every city, including Phnom Penh, was relocated to the countryside. This was ordered by the Communist Party of Kampuchea and the secret police Santebal, and they then established an infamous prison gulag inside the torture chamber called Tuol Sleng (S-21). Cambodia proceeded to implement the Year Zero policy, hastening isolation from the rest of the world. Ultimately, the authority of the Khmer Rouge and its isolationist policy would collapse in 1978 when the Vietnamese invaded the country and then overthrew Pol Pot on 7 January 1979.
### China
After Zheng He\'s voyages in the 15th century, the foreign policy of the Ming dynasty in China became increasingly isolationist. The Hongwu Emperor was not the first to propose the policy to ban all maritime shipping in 1390. The Qing dynasty that came after the Ming dynasty often continued the Ming dynasty\'s isolationist policies. Wokou, which literally translates to \"Japanese pirates\" or \"dwarf pirates\", were pirates who raided the coastlines of China, Japan, and Korea, and were one of the key primary concerns, although the maritime ban was not without some control.
In the winter of 1757, the Qianlong Emperor declared that---effective the next year---Guangzhou was to be the only Chinese port permitted to foreign traders, beginning the Canton System.
Since the division of the territory following the Chinese Civil War in 1949, China is divided into two regimes with the People\'s Republic of China solidified control on mainland China while the existing Republic of China was confined to the island of Taiwan as both governments lay claim to each other\'s sovereignty. While the PRC is recognized by the United Nations, European Union, and the majority of the world\'s states, the ROC remains diplomatically isolated although 15 states recognize it as \"China\" with some countries maintaining unofficial diplomatic relations through trade offices.
### Japan
From 1641 to 1853, the Tokugawa shogunate of Japan enforced a policy called *kaikin*. The policy prohibited foreign contact with most outside countries. The commonly held idea that Japan was entirely closed, however, is misleading. In fact, Japan maintained limited-scale trade and diplomatic relations with China, Korea, and the Ryukyu Islands, as well as the Dutch Republic as the only Western trading partner of Japan for much of the period.
The culture of Japan developed with limited influence from the outside world and had one of the longest stretches of peace in history. During this period, Japan developed thriving cities, castle towns, increasing commodification of agriculture and domestic trade, wage labor, increasing literacy and concomitant print culture, laying the groundwork for modernization even as the shogunate itself grew weak.
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# Isolationism
## By country {#by_country}
### Korea
In 1863, Emperor Gojong took the throne of the Joseon Dynasty when he was a child. His father, Regent Heungseon Daewongun, ruled for him until Gojong reached adulthood. During the mid-1860s he was the main proponent of isolationism and the principal instrument of the persecution of both native and foreign Catholics.
Following the division of the peninsula after independence from Japan at the end of World War II, Kim Il Sung inaugurated an isolationist nationalist regime in the North, which would continued by his son and grandson following his death in 1994.
### Paraguay
In 1814, three years after it gained its independence on May 14, 1811, Paraguay was taken over by the dictator José Gaspar Rodríguez de Francia. During his rule which lasted from 1814 until his death in 1840, he closed Paraguay\'s borders and prohibited trade or any relationship between Paraguay and the outside world. The Spanish settlers who had arrived in Paraguay just before it gained its independence were required to marry old colonists or the native Guaraní in order to create a single Paraguayan people.
Francia had a particular dislike of foreigners, and any foreigners who attempted to enter the country were not allowed to leave for an indefinite period of time. An independent character, he hated European influences and the Catholic Church and in order to try to keep foreigners at bay, he turned church courtyards into artillery parks and turned confession boxes into border sentry posts.
### United States {#united_states}
Some scholars, such as Robert J. Art, believe that the United States had an isolationist history, but most other scholars dispute that claim by describing the United States as following a strategy of unilateralism or non-interventionism rather than a strategy of isolationism. Robert Art makes his argument in *A Grand Strategy for America* (2003). Books that have made the argument that the United States followed unilaterism instead of isolationism include Walter A. McDougall\'s *Promised Land, Crusader State* (1997), John Lewis Gaddis\'s *Surprise, Security, and the American Experience* (2004), and Bradley F. Podliska\'s *Acting Alone* (2010). Both sides claim policy prescriptions from George Washington\'s Farewell Address as evidence for their argument. Bear F. Braumoeller argues that even the best case for isolationism, the United States in the interwar period, has been widely misunderstood and that Americans proved willing to fight as soon as they believed a genuine threat existed. Warren F. Kuehl and Gary B. Ostrower argue:
> Events during and after the Revolution related to the treaty of alliance with France, as well as difficulties arising over the neutrality policy pursued during the French revolutionary wars and the Napoleonic wars, encouraged another perspective. A desire for separateness and unilateral freedom of action merged with national pride and a sense of continental safety to foster the policy of isolation. Although the United States maintained diplomatic relations and economic contacts abroad, it sought to restrict these as narrowly as possible in order to retain its independence. The Department of State continually rejected proposals for joint cooperation, a policy made explicit in the Monroe Doctrine\'s emphasis on unilateral action. Not until 1863 did an American delegate attend an international conference.
## Criticism
Isolationism has been criticized for the lack of aiding nations with major troubles. One notable example is that of American isolationism, which Benjamin Schwartz described as a \"tragedy\" inspired by Puritanism.
Some modern American conservative commentators assert that labeling others as isolationist is used against individuals in a pejorative manner
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# Image and Scanner Interface Specification
**Image and Scanner Interface Specification** (**ISIS**) is an industry standard interface for image scanning technologies, developed by Pixel Translations in 1990 (which became EMC Corporation\'s Captiva Software and later acquired by OpenText).
ISIS is an open standard for scanner control and a complete image-processing framework. It is currently supported by a number of application and scanner vendors.
## Functions
The modular design allows the scanner to be accessed both directly or with built-in routines to handle most situations automatically. A message-based interface with tags is used so that features, operations, and formats not yet supported by ISIS can be added as desired without waiting for a new version of the specification.
The standard addresses all of the issues that an application using a scanner needs to be concerned with. Functions include but are not limited to selecting, installing, and configuring a new scanner; setting scanner-specific parameters; scanning, reading and writing files, and fast image scaling, rotating, displaying, and printing. Drivers have been written to dynamically process data for operations such as converting grayscale to binary image data.
An ISIS interface can run scanners at or above their rated speed by linking drivers together in a pipe so that data flows from a scanner driver to compression driver, to packaging driver, to a file, viewer, or printer in a continuous stream, usually without the need to buffer more than a small portion of the full image. As a result of using the piping method, each driver can be optimized to perform one function well. Drivers are typically small and modular in order to make it simple to add new functionality to an existing application
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# Ivo Caprino
**Ivo Caprino** (17 February 1920 -- 8 February 2001) was a Norwegian film director and writer, best known for his puppet films. His most noted film, *Flåklypa Grand Prix* (Pinchcliffe Grand Prix), was made in 1975.
## Early life {#early_life}
Caprino was born 17 February 1920 in Oslo, the son of Italian furniture designer Mario Caprino and the artist, Ingeborg \"Ingse\" Gude, who was a granddaughter of the painter Hans Gude.
## Early career {#early_career}
In the mid-1940s, Caprino helped his mother design puppets for a puppet theatre, which inspired him to try making a film using his mother\'s designs. Ivo used the surplus puppets as inspiration for his first animated film, *Tim and Tøffe* (1948), the result of their collaboration. The eight minute film, however, was not released until 1949. Several other films followed, including two 15-minute shorts that are still shown regularly in Norway, *Veslefrikk med Fela* (*Little Freddy and his Fiddle*), based on a Norwegian folk tale; and *Karius og Baktus*, a story by Thorbjørn Egner of two little trolls---representing caries and bacterium---living in a boy\'s teeth. Gude made the puppets for these films as well.
### Work with Ingse Caprino {#work_with_ingse_caprino}
Following the success of *Tim og Tøffe*, Gude was involved in all of her son\'s films until 1963. Gude made some puppets for a production by Frithjof Tidemand-Johannessen. Caprino had set up a film studio in the manor house, and Gude started working full-time on new puppets, which often had luscious proportions. The film, *Veslefrikk med Fela*, was awarded the best children\'s film at the 13th Venice International Film Festival in 1952. The commissioned production, *Den standhaftige tinnsoldat* (*The Steadfast Tin Soldier*), won several international awards.
Gude filled the role of cinematographer on the last film collaboration with her son. The puppet\'s voice role being played by Liv Strømsted. Gude died 9 December 1963 at Snarøya. The production of puppets was afterwards taken over by her granddaughter Ivonne Caprino.
## Innovations
When making *Tim og Tøffe*, Caprino invented a method for controlling the puppet\'s movements in real time. The technique can be described as a primitive, mechanical version of animatronics. Caprino\'s films received good reviews, and he quickly became a celebrity in Norway. When he switched to traditional stop motion film-making, Caprino tried to maintain the impression that he was still using some kind of \"magic\" technology to make the puppets move, even though all his later films were made with traditional stop motion techniques. Another innovative method used by the team, was the use of condoms for the creation of the puppets\' facial skin.
In addition to the short films, Caprino produced dozens of advertising films with puppets. In 1959, he directed a live action feature film, *Ugler i Mosen*, which also contained stop motion sequences. He then made a feature film about Peter Christen Asbjørnsen, who had travelled around Norway in the 19th century collecting traditional folk tales. The plan was to use live action for the sequences showing Asbjørnsen, and then to realise the folk tales using stop motion. Unfortunately, Caprino was unable to secure funding for the project, so he ended up making the planned folk tale sequences as separate 16-minute puppet films, book-ended by live action sequences showing Asbjørnsen.
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# Ivo Caprino
## *The Pinchcliffe Grand Prix* {#the_pinchcliffe_grand_prix}
In 1970, Caprino and his small team of collaborators, started work on a 25-minute TV special, which eventually became *The Pinchcliffe Grand Prix*. Based on a series of books by Norwegian cartoonist and author, Kjell Aukrust, it featured a group of eccentric characters all living in the small village of Pinchcliffe. The TV special was a collection of sketches based on Aukrust\'s books, with no real story line. After 1.5 years of work, it was decided that it didn\'t really work as a whole, so production on the TV special was stopped (except for some very short clips, no material from it has ever been seen by the public), and Caprino and Aukrust instead wrote a screenplay for a feature film using the characters and environments that had already been built.
The result was *The Pinchcliffe Grand Prix*, which stars Theodore Rimspoke (No. Reodor Felgen) and his two assistants, Sonny Duckworth (No. Solan Gundersen), a cheerful and optimistic bird, and Lambert (No. Ludvig), a nervous, pessimistic and melancholic hedgehog. Theodore works as a bicycle repairman, though he spends most of his time inventing weird Rube Goldberg-like contraptions. One day, the trio discover that one of Theodore\'s former assistants, Rudolph Gore-Slimey (*Rudolf Blodstrupmoen*), has stolen his design for a race car engine, and has become a world champion Formula One driver. Sonny secures funding from an Arab oil sheik who happens to be vacationing in Pinchcliffe, and the trio then build a gigantic racing car, *Il Tempo Gigante*---a fabulous construction with two engines, radar, and its own blood bank. Theodore then enters a race, and ends up winning, beating Gore-Slimey despite his attempts at sabotage.
The film was made in 3.5 years by a team of five people. Caprino directed and animated. Bjarne Sandemose (Caprino\'s principal collaborator throughout his career) built the sets and the cars, and was in charge of the technical side. Ingeborg Riiser modeled the puppets and Gerd Alfsen made the costumes and props. When it came out in 1975, The movie was a large success in Norway, selling one million tickets in its first year of release. It remains the biggest box office hit of all time in Norway. Caprino Studios claims it has sold 5.5 million tickets to date.
There is a rollercoaster replica of Il Tempo Gigante at Hunderfossen Familiepark.
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# Ivo Caprino
## Later career {#later_career}
Except for some TV work in the late 1970s, Caprino made no more puppet films, focusing instead on creating attractions for the *Hunderfossen* theme park outside Lillehammer based on his folk tale movies, and making tourist films using a custom built multi camera setup of his own design that shoots 280 degrees panorama movies.
## Death and afterwards {#death_and_afterwards}
Caprino was born and died in Oslo, but lived all of his life at Snarøya, Bærum. He died in 2001 after having lived several years with cancer. Since Caprino\'s death, his son Remo has had moderate success developing a computer game based on *Flåklypa Grand Prix*
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# Isaac Bonewits
**Phillip Emmons Isaac Bonewits** (October 1, 1949 -- August 12, 2010) was an American Neo-Druid who wrote a number of books on the subject of Neopaganism and magic. Bonewits was a public speaker, liturgist, singer and songwriter, and founder of the Neopagan organizations Ár nDraíocht Féin (ADF) and the Aquarian Anti-Defamation League.
## Early life and education {#early_life_and_education}
Bonewits was born on October 1, 1949, in Royal Oak, Michigan, as the fourth of five children. His father was a Presbyterian while his mother a Catholic. Spending much of his childhood in Ferndale, Michigan, he was moved at age 12 to San Clemente, California, where he spent a short time in a Catholic high school before he went back to public school to graduate from high school a year early. He enrolled at UC Berkeley in 1966 and graduated in 1970 with a Bachelor of Arts in magic, perhaps becoming the first and only person known to have ever received any kind of academic degree in magic from an accredited university.
In 1966, while enrolled at UC Berkeley, Bonewits joined the Reformed Druids of North America (RDNA). Bonewits was ordained as a Neo-druid priest in 1969. During this period, the 18-year-old Bonewits was also recruited by the Church of Satan, but left due to political and philosophical conflicts with Anton LaVey. During his stint in the Church of Satan, Bonewits appeared in some scenes of the 1970 documentary *Satanis: The Devil\'s Mass*. Bonewits, in his article \"My Satanic Adventure\", asserts that the rituals in *Satanis* were staged for the movie at the behest of the filmmakers and were not authentic ceremonies.
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# Isaac Bonewits
## Career
### 1970s: writer and editor {#s_writer_and_editor}
Bonewits\' first book, *Real Magic*, was published in 1971. Between 1973 and 1975 Bonewits was employed as the editor of *Gnostica* magazine in Minnesota (published by Llewellyn Publications). He established an offshoot group of the Reformed Druids of North America (RDNA) called the Schismatic Druids of North America, and helped create a group called the Hasidic Druids of North America (despite, in his words, his \"lifelong status as a gentile\"). He also founded the short-lived Aquarian Anti-Defamation League (AADL), an early Pagan civil rights group.
In 1976, Bonewits moved back to Berkeley and rejoined his original grove there, now part of the New Reformed Druids of North America (NRDNA). He was later elected Archdruid of the Berkeley Grove.
### 1980s: founding of Ár nDraíocht Féin {#s_founding_of_ár_ndraíocht_féin}
Throughout his life Bonewits had varying degrees of involvement with occult groups including Gardnerian Wicca and the New Reformed Orthodox Order of the Golden Dawn (a Wiccan organization not to be confused with the Hermetic Order of the Golden Dawn). Bonewits was a regular presenter at Neopagan conferences and festivals all over the US, as well as attending gaming conventions in the Bay Area. He promoted his book *Authentic Thaumaturgy* to gamers as a way of organizing *Dungeons & Dragons* games.
In 1983, Bonewits founded Ár nDraíocht Féin (also known as \"A Druid Fellowship\" or ADF), which was incorporated in 1990 in the state of Delaware as a U.S. 501(c)3 non-profit organization. Although illness curtailed many of his activities and travels for a time, he remained Archdruid of ADF until 1996. In that year, he resigned from the position of Archdruid but retained the lifelong title of ADF Archdruid Emeritus.
### Musician and activist {#musician_and_activist}
A songwriter, singer, and recording artist, he produced two CDs of pagan music and numerous recorded lectures and panel discussions, produced and distributed by the Association for Consciousness Exploration. He lived in Rockland County, New York, and was a member of the Covenant of Unitarian Universalist Pagans (CUUPS).
Bonewits encouraged charity programs to help Neopagan seniors, and in January 2006 was the keynote speaker at the Conference On Current Pagan Studies at the Claremont Graduate University in Claremont, CA.
## Personal life {#personal_life}
Bonewits was married five times. He was married to Rusty Elliot from 1973 to 1976. His second wife was Selene Kumin Vega, followed by marriage to Sally Eaton (1980 to 1985). His fourth wife was author Deborah Lipp, from 1988 to 1998. On July 23, 2004, he was married in a handfasting ceremony to a former vice-president of the Covenant of Unitarian Universalist Pagans, Phaedra Heyman Bonewits. At the time of the handfasting, the marriage was not yet legal because he had not yet been legally divorced from Lipp, although they had been separated for several years. Paperwork and legalities caught up on December 31, 2007, making them legally married.
Bonewits\' only child was born to Lipp in 1990.
## Illness and death {#illness_and_death}
In 1990, Bonewits was diagnosed with eosinophilia-myalgia syndrome. The illness was a factor in his eventual resignation from the position of Archdruid of the ADF.
On October 25, 2009, Bonewits was diagnosed with a rare form of colon cancer, for which he underwent treatment. He died at home, on August 12, 2010, surrounded by his family.
## Accusations of sexual assault {#accusations_of_sexual_assault}
In 2018, accusations of sexual abuse against a minor rose against ADF founder Bonewits relating to his relationship with Moira Greyland when she was six years old. Greyland said in her book, \'The Last Closet: the Dark Side of Avalon\':
In light of this accusation, ADF, the lead pagan organization that Issac Bonewits founded, removed his name from their website and repudiated him.
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# Isaac Bonewits
## Contributions to Neopaganism {#contributions_to_neopaganism}
In his book *Real Magic* (1971), Bonewits proposed his \"Laws of Magic\". These \"laws\" are synthesized from a multitude of belief systems from around the world to explain and categorize magical beliefs within a cohesive framework. Many interrelationships exist, and some belief systems are subsets of others. This work was chosen by Dennis Wheatley in the 1970s to be part of his publishing project *Library of the Occult*.
Bonewits also coined much of the modern terminology used to articulate the themes and issues that affect the North American Neopagan community.
- Pioneered the modern usage of the terms \"thealogy\", \"Paleo-Paganism\", \"Meso-Paganism\", and numerous other retronyms.
- Possibly coined the term \"Pagan Reconstructionism\", though the communities in question would later diverge from his initial meaning.
- Founded Ar nDraiocht Fein, which was incorporated in 1990 in the state of Delaware as a U.S. 501(c)3 non-profit organization.
- Developed the *Advanced Bonewits Cult Danger Evaluation Frame* (ABCDEF).
- Coined the phrase \"Never Again the Burning\".
- Critiqued the Burning Times / Old Religion Murray thesis (in *Bonewits\'s Essential Guide to Witchcraft and Wicca*).
- In his book *Real Magic* (1971), Bonewits proposed his hypothesis on the Laws of Magic, which were then elaborated in his RPG supplement *Authentic Thaumaturgy*. The book makes it clear it is an adaptation of the ideas from Real Magic to gaming with the Laws presented being abbreviated from those in *Real Magic*
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# Insulator (electricity)
An **electrical insulator** is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials---semiconductors and conductors---conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are non-metals.
A perfect insulator does not exist because even the materials used as insulators contain small numbers of mobile charges (charge carriers) which can carry current. In addition, all insulators become electrically conductive when a sufficiently large voltage is applied that the electric field tears electrons away from the atoms. This is known as electrical breakdown, and the voltage at which it occurs is called the breakdown voltage of an insulator. Some materials such as glass, paper and PTFE, which have high resistivity, are very good electrical insulators. A much larger class of materials, even though they may have lower bulk resistivity, are still good enough to prevent significant current from flowing at normally used voltages, and thus are employed as insulation for electrical wiring and cables. Examples include rubber-like polymers and most plastics which can be thermoset or thermoplastic in nature.
Insulators are used in electrical equipment to support and separate electrical conductors without allowing current through themselves. An insulating material used in bulk to wrap electrical cables or other equipment is called *insulation*. The term *insulator* is also used more specifically to refer to insulating supports used to attach electric power distribution or transmission lines to utility poles and transmission towers. They support the weight of the suspended wires without allowing the current to flow through the tower to ground.
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# Insulator (electricity)
## Physics of conduction in solids {#physics_of_conduction_in_solids}
Electrical insulation is the absence of electrical conduction. Electronic band theory (a branch of physics) explains that electric charge flows when quantum states of matter are available into which electrons can be excited. This allows electrons to gain energy and thereby move through a conductor, such as a metal, if an electric potential difference is applied to the material. If no such states are available, the material is an insulator.
Most insulators have a large band gap. This occurs because the \"valence\" band containing the highest energy electrons is full, and a large energy gap separates this band from the next band above it. There is always some voltage (called the breakdown voltage) that gives electrons enough energy to be excited into this band. Once this voltage is exceeded, electrical breakdown occurs, and the material ceases being an insulator, passing charge. This is usually accompanied by physical or chemical changes that permanently degrade the material and its insulating properties.
When the electric field applied across an insulating substance exceeds in any location the threshold breakdown field for that substance, the insulator suddenly becomes a conductor, causing a large increase in current, an electric arc through the substance. Electrical breakdown occurs when the electric field in the material is strong enough to accelerate free charge carriers (electrons and ions, which are always present at low concentrations) to a high enough velocity to knock electrons from atoms when they strike them, ionizing the atoms. These freed electrons and ions are in turn accelerated and strike other atoms, creating more charge carriers, in a chain reaction. Rapidly the insulator becomes filled with mobile charge carriers, and its resistance drops to a low level. In a solid, the breakdown voltage is proportional to the band gap energy. When corona discharge occurs, the air in a region around a high-voltage conductor can break down and ionise without a catastrophic increase in current. However, if the region of air breakdown extends to another conductor at a different voltage it creates a conductive path between them, and a large current flows through the air, creating an *electric arc*. Even a vacuum can suffer a sort of breakdown, but in this case the breakdown or vacuum arc involves charges ejected from the surface of metal electrodes rather than produced by the vacuum itself.
In addition, all insulators become conductors at very high temperatures as the thermal energy of the valence electrons is sufficient to put them in the conduction band.
In certain capacitors, shorts between electrodes formed due to dielectric breakdown can disappear when the applied electric field is reduced.`{{Relevance inline|date=October 2017}}`{=mediawiki}
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# Insulator (electricity)
## Uses
A flexible coating of an insulator is often applied to electric wire and cable; this assembly is called *insulated wire*. Wires sometimes don\'t use an insulating coating, just air, when a solid (e.g. plastic) coating may be impractical. Wires that touch each other produce cross connections, short circuits, and fire hazards. In coaxial cable the center conductor must be supported precisely in the middle of the hollow shield to prevent electro-magnetic wave reflections. Wires that expose high voltages can cause human shock and electrocution hazards.
Most insulated wire and cable products have maximum ratings for voltage and conductor temperature. The product may not have an ampacity (current-carrying capacity) rating, since this is dependent on the surrounding environment (e.g. ambient temperature).
In electronic systems, printed circuit boards are made from epoxy plastic and fibreglass. The nonconductive boards support layers of copper foil conductors. In electronic devices, the tiny and delicate active components are embedded within nonconductive epoxy or phenolic plastics, or within baked glass or ceramic coatings.
In microelectronic components such as transistors and ICs, the silicon material is normally a conductor because of doping, but it can easily be selectively transformed into a good insulator by the application of heat and oxygen. Oxidised silicon is quartz, i.e. silicon dioxide, the primary component of glass.
In high voltage systems containing transformers and capacitors, liquid insulator oil is the typical method used for preventing arcs. The oil replaces air in spaces that must support significant voltage without electrical breakdown. Other high voltage system insulation materials include ceramic or glass wire holders, gas, vacuum, and simply placing wires far enough apart to use air as insulation.
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# Insulator (electricity)
## Insulation in electrical apparatus {#insulation_in_electrical_apparatus}
The most important insulation material is air. A variety of solid, liquid, and gaseous insulators are also used in electrical apparatus. In smaller transformers, generators, and electric motors, insulation on the wire coils consists of up to four thin layers of polymer varnish film. Film-insulated magnet wire permits a manufacturer to obtain the maximum number of turns within the available space. Windings that use thicker conductors are often wrapped with supplemental fiberglass insulating tape. Windings may also be impregnated with insulating varnishes to prevent electrical corona and reduce magnetically induced wire vibration. Large power transformer windings are still mostly insulated with paper, wood, varnish, and mineral oil; although these materials have been used for more than 100 years, they still provide a good balance of economy and adequate performance. Busbars and circuit breakers in switchgear may be insulated with glass-reinforced plastic insulation, treated to have low flame spread and to prevent tracking of current across the material.
In older apparatus made up to the early 1970s, boards made of compressed asbestos may be found; while this is an adequate insulator at power frequencies, handling or repairs to asbestos material can release dangerous fibers into the air and must be carried out cautiously. Wire insulated with felted asbestos was used in high-temperature and rugged applications from the 1920s. Wire of this type was sold by General Electric under the trade name \"Deltabeston.\"
Live-front switchboards up to the early part of the 20th century were made of slate or marble. Some high voltage equipment is designed to operate within a high pressure insulating gas such as sulfur hexafluoride. Insulation materials that perform well at power and low frequencies may be unsatisfactory at radio frequency, due to heating from excessive dielectric dissipation.
Electrical wires may be insulated with polyethylene, crosslinked polyethylene (either through electron beam processing or chemical crosslinking), PVC, Kapton, rubber-like polymers, oil impregnated paper, Teflon, silicone, or modified ethylene tetrafluoroethylene (ETFE). Larger power cables may use compressed inorganic powder, depending on the application.
Flexible insulating materials such as PVC (polyvinyl chloride) are used to insulate the circuit and prevent human contact with a \'live\' wire -- one having voltage of 600 volts or less. Alternative materials are likely to become increasingly used due to EU safety and environmental legislation making PVC less economic.
In electrical apparatus such as motors, generators, and transformers, various insulation systems are used, classified by their maximum recommended working temperature to achieve acceptable operating life. Materials range from upgraded types of paper to inorganic compounds.
### Class I and Class II insulation {#class_i_and_class_ii_insulation}
All portable or hand-held electrical devices are insulated to protect their user from harmful shock.
Class I insulation requires that the metal body and other exposed metal parts of the device be connected to earth via a *grounding wire* that is earthed at the main service panel---but only needs basic insulation on the conductors. This equipment needs an extra pin on the power plug for the grounding connection.
Class II insulation means that the device is *double insulated*. This is used on some appliances such as electric shavers, hair dryers and portable power tools. Double insulation requires that the devices have both basic and supplementary insulation, each of which is sufficient to prevent electric shock. All internal electrically energized components are totally enclosed within an insulated body that prevents any contact with \"live\" parts. In the EU, double insulated appliances all are marked with a symbol of two squares, one inside the other.
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# Insulator (electricity)
## Telegraph and power transmission insulators {#telegraph_and_power_transmission_insulators}
Conductors for overhead high-voltage electric power transmission are bare, and are insulated by the surrounding air. Conductors for lower voltages in distribution may have some insulation but are often bare as well. Insulating supports are required at the points where they are supported by utility poles or transmission towers. Insulators are also required where wire enters buildings or electrical devices, such as transformers or circuit breakers, for insulation from the case. Often these are bushings, which are hollow insulators with the conductor inside them.
### Materials
Insulators used for high-voltage power transmission are made from glass, porcelain or composite polymer materials. Porcelain insulators are made from clay, quartz or alumina and feldspar, and are covered with a smooth glaze to shed water. Insulators made from porcelain rich in alumina are used where high mechanical strength is a criterion. Porcelain has a dielectric strength of about 4--10 kV/mm. Glass has a higher dielectric strength, but it attracts condensation and the thick irregular shapes needed for insulators are difficult to cast without internal strains. Some insulator manufacturers stopped making glass insulators in the late 1960s, switching to ceramic materials.
Some electric utilities use polymer composite materials for some types of insulators. These are typically composed of a central rod made of fibre reinforced plastic and an outer weathershed made of silicone rubber or ethylene propylene diene monomer rubber (EPDM). Composite insulators are less costly, lighter in weight, and have excellent hydrophobic properties. This combination makes them ideal for service in polluted areas. However, these materials do not yet have the long-term proven service life of glass and porcelain.
<File:Power> line with ceramic insulators.jpg\|Power lines supported by ceramic pin-type insulators in California, USA <File:Ceramic> electric insulator.jpg\|upright\|left\|10 kV ceramic insulator, showing sheds
### Design
The electrical breakdown of an insulator due to excessive voltage can occur in one of two ways:
- A *puncture arc* is a breakdown and conduction of the material of the insulator, causing an electric arc through the interior of the insulator. The heat resulting from the arc usually damages the insulator irreparably. *Puncture voltage* is the voltage across the insulator (when installed in its normal manner) that causes a puncture arc.
- A *flashover arc* is a breakdown and conduction of the air around or along the surface of the insulator, causing an arc along the outside of the insulator. Insulators are usually designed to withstand flashover without damage. *Flashover voltage* is the voltage that causes a flash-over arc.
Most high voltage insulators are designed with a lower flashover voltage than puncture voltage, so they flash over before they puncture, to avoid damage.
Dirt, pollution, salt, and particularly water on the surface of a high voltage insulator can create a conductive path across it, causing leakage currents and flashovers. The flashover voltage can be reduced by more than 50% when the insulator is wet. High voltage insulators for outdoor use are shaped to maximise the length of the leakage path along the surface from one end to the other, called the creepage length, to minimise these leakage currents. To accomplish this the surface is moulded into a series of corrugations or concentric disc shapes. These usually include one or more *sheds*; downward facing cup-shaped surfaces that act as umbrellas to ensure that the part of the surface leakage path under the \'cup\' stays dry in wet weather. Minimum creepage distances are 20--25 mm/kV, but must be increased in high pollution or airborne sea-salt areas.
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# Insulator (electricity)
## Telegraph and power transmission insulators {#telegraph_and_power_transmission_insulators}
### Types
thumb\|upright=0.8\|A three-phase insulator used on distribution lines, typically 13.8 kV phase to phase. The lines are held in a diamond pattern, multiple insulators used between poles. Insulators are characterized in several common classes:
- Pin insulator - The pin-type insulator is mounted on a pin affixed on the cross-arm of the pole. The insulator has a groove near the top just below the crown. The conductor passes through this groove and is tied to the insulator with annealed wire of the same material as the conductor. Pin-type insulators are used for transmission and distribution of communication signals, and electric power at voltages up to 33 kV. Insulators made for operating voltages between 33 kV and 69 kV tend to be bulky and have become uneconomical.
- Post insulator - A type of insulator in the 1930s that is more compact than traditional pin-type insulators and which has rapidly replaced many pin-type insulators on lines up to 69 kV and in some configurations, can be made for operation at up to 115 kV.
- Suspension insulator - For voltages greater than 33 kV, it is a usual practice to use suspension type insulators, consisting of a number of glass or porcelain discs connected in series by metal links in the form of a string. The conductor is suspended at the bottom end of this string while the top end is secured to the cross-arm of the tower. The number of disc units used depends on the voltage.
- Strain insulator - A *dead end* or *anchor* pole or tower is used where a straight section of line ends, or angles off in another direction. These poles must withstand the lateral (horizontal) tension of the long straight section of wire. To support this lateral load, strain insulators are used. For low voltage lines (less than 11 kV), shackle insulators are used as strain insulators. However, for high voltage transmission lines, strings of cap-and-pin (suspension) insulators are used, attached to the crossarm in a horizontal direction. When the tension load in lines is exceedingly high, such as at long river spans, two or more strings are used in parallel.
- Shackle insulator - In early days, the shackle insulators were used as strain insulators. But nowaday, they are frequently used for low voltage distribution lines. Such insulators can be used either in a horizontal position or in a vertical position. They can be directly fixed to the pole with a bolt or to the cross arm.
- Bushing - enables one or several conductors to pass through a partition such as a wall or a tank, and insulates the conductors from it.
- Line post insulator
- Station post insulator
- Cut-out
### Sheath insulator {#sheath_insulator}
An insulator that protects a full-length of bottom-contact third rail. `{{expand section|date=April 2021}}`{=mediawiki}
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# Insulator (electricity)
## Telegraph and power transmission insulators {#telegraph_and_power_transmission_insulators}
### Suspension insulators {#suspension_insulators}
+---------------+-------+
| Line voltage\ | Discs |
| (kV) | |
+===============+=======+
| 34.5 | 3 |
+---------------+-------+
| 69 | 4 |
+---------------+-------+
| 115 | 6 |
+---------------+-------+
| 138 | 8 |
+---------------+-------+
| 161 | 11 |
+---------------+-------+
| 230 | 14 |
+---------------+-------+
| 287 | 15 |
+---------------+-------+
| 345 | 18 |
+---------------+-------+
| 360 | 23 |
+---------------+-------+
| 400 | 24 |
+---------------+-------+
| 500 | 34 |
+---------------+-------+
| 600 | 44 |
+---------------+-------+
| 750 | 59 |
+---------------+-------+
| 765 | 60 |
+---------------+-------+
: Typical number of disc insulator units for standard line voltages
Pin-type insulators are unsuitable for voltages greater than about 69 kV line-to-line. Higher voltage transmission lines usually use modular suspension insulator designs. The wires are suspended from a \'string\' of identical disc-shaped insulators that attach to each other with metal clevis pin or ball-and-socket links. The advantage of this design is that insulator strings with different breakdown voltages, for use with different line voltages, can be constructed by using different numbers of the basic units. String insulators can be made for any practical transmission voltage by adding insulator elements to the string. Also, if one of the insulator units in the string breaks, it can be replaced without discarding the entire string.
Each unit is constructed of a ceramic or glass disc with a metal cap and pin cemented to opposite sides. To make defective units obvious, glass units are designed so that an overvoltage causes a puncture arc through the glass instead of a flashover. The glass is heat-treated so it shatters, making the damaged unit visible. However the mechanical strength of the unit is unchanged, so the insulator string stays together.
Standard suspension disc insulator units are 25 cm in diameter and 15 cm long, can support a load of 80-120 kN, have a dry flashover voltage of about 72 kV, and are rated at an operating voltage of 10--12 kV. However, the flashover voltage of a string is less than the sum of its component discs, because the electric field is not distributed evenly across the string but is strongest at the disc nearest to the conductor, which flashes over first. Metal *grading rings* are sometimes added around the disc at the high voltage end, to reduce the electric field across that disc and improve flashover voltage.
In very high voltage lines the insulator may be surrounded by corona rings. These typically consist of toruses of aluminium (most commonly) or copper tubing attached to the line. They are designed to reduce the electric field at the point where the insulator is attached to the line, to prevent corona discharge, which results in power losses.
<File:pylon.detail.arp.750pix.jpg%7CSuspension> insulator string (the vertical string of discs) on a 275 kV suspension pylon <File:LIC> U70.jpg\|Suspended glass disc insulator unit used in suspension insulator strings for high voltage transmission lines
### History
The first electrical systems to make use of insulators were telegraph lines; direct attachment of wires to wooden poles was found to give very poor results, especially during damp weather.
The first glass insulators used in large quantities had an unthreaded pinhole. These pieces of glass were positioned on a tapered wooden pin, vertically extending upwards from the pole\'s crossarm (commonly only two insulators to a pole and maybe one on top of the pole itself). Natural contraction and expansion of the wires tied to these \"threadless insulators\" resulted in insulators unseating from their pins, requiring manual reseating.
Amongst the first to produce ceramic insulators were companies in the United Kingdom, with Stiff and Doulton using stoneware from the mid-1840s, Joseph Bourne (later renamed Denby) producing them from around 1860 and Bullers from 1868. Utility patent number [48,906](http://reference.insulators.info/patents/detail/?patent=48906&type=U) was granted to Louis A. Cauvet on 25 July 1865 for a process to produce insulators with a threaded pinhole: pin-type insulators still have threaded pinholes.
The invention of suspension-type insulators made high-voltage power transmission possible. As transmission line voltages reached and passed 60,000 volts, the insulators required become very large and heavy, with insulators made for a safety margin of 88,000 volts being about the practical limit for manufacturing and installation. Suspension insulators, on the other hand, can be connected into strings as long as required for the line\'s voltage.
A large variety of telephone, telegraph and power insulators have been made; some people collect them, both for their historic interest and for the aesthetic quality of many insulator designs and finishes. One collectors organisation is the US National Insulator Association, which has over 9,000 members.
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# Insulator (electricity)
## Insulation of antennas {#insulation_of_antennas}
Often a broadcasting radio antenna is built as a mast radiator, which means that the entire mast structure is energised with high voltage and must be insulated from the ground. Steatite mountings are used. They have to withstand not only the voltage of the mast radiator to ground, which can reach values up to 400 kV at some antennas, but also the weight of the mast construction and dynamic forces. Arcing horns and lightning arresters are necessary because lightning strikes to the mast are common.
Guy wires supporting antenna masts usually have strain insulators inserted in the cable run, to keep the high voltages on the antenna from short circuiting to ground or creating a shock hazard. Often guy cables have several insulators, placed to break up the cable into lengths that prevent unwanted electrical resonances in the guy. These insulators are usually ceramic and cylindrical or egg-shaped (see picture). This construction has the advantage that the ceramic is under compression rather than tension, so it can withstand greater load, and that if the insulator breaks, the cable ends are still linked.
These insulators also have to be equipped with overvoltage protection equipment. For the dimensions of the guy insulation, static charges on guys have to be considered. For high masts, these can be much higher than the voltage caused by the transmitter, requiring guys divided by insulators in multiple sections on the highest masts. In this case, guys which are grounded at the anchor basements via a coil - or if possible, directly - are the better choice.
Feedlines attaching antennas to radio equipment, particularly twin-lead type, often must be kept at a distance from metal structures. The insulated supports used for this purpose are called *standoff insulators*
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# Internetworking
**Internetworking** is the practice of interconnecting multiple computer networks. Typically, this enables any pair of hosts in the connected networks to exchange messages irrespective of their hardware-level networking technology. The resulting system of interconnected networks is called an *internetwork*, or simply an *internet*.
The most notable example of internetworking is the Internet, a network of networks based on many underlying hardware technologies. The Internet is defined by a unified global addressing system, packet format, and routing methods provided by the Internet Protocol.`{{r|CDKB2012|p=103}}`{=mediawiki}
The term *internetworking* is a combination of the components *inter* (between) and *networking*. An earlier term for an internetwork is **catenet**, a short-form of *(con)catenating networks*.
## History
The first international heterogenous resource sharing network was developed by the computer science department at University College London (UCL) who interconnected the ARPANET with early British academic networks beginning in 1973. In the ARPANET, the network elements used to connect individual networks were called gateways, but the term has been deprecated in this context, because of possible confusion with functionally different devices. By 1973-4, researchers in France, the United States, and the United Kingdom had worked out an approach to internetworking where the differences between network protocols were hidden by using a common internetwork protocol, and instead of the network being responsible for reliability, as in the ARPANET, the hosts became responsible, as demonstrated in the CYCLADES network. Researchers at Xerox PARC outlined the idea of Ethernet and the PARC Universal Packet (PUP) for internetworking. Research at the National Physical Laboratory in the United Kingdom confirmed establishing a common host protocol would be more reliable and efficient. The ARPANET connection to UCL later evolved into SATNET. In 1977, ARPA demonstrated a three-way internetworking experiment, which linked a mobile vehicle in PRNET with nodes in the ARPANET, and, via SATNET, to nodes at UCL. The X.25 protocol, on which public data networks were based in the 1970s and 1980s, was supplemented by the X.75 protocol which enabled internetworking.
Today the interconnecting gateways are called routers. The definition of an internetwork today includes the connection of other types of computer networks such as personal area networks.
### Catenet
Catenet, a short-form of *(con)catenating networks,* is obsolete terminolgy for a system of packet-switched communication networks interconnected via gateways.
The term was coined by Louis Pouzin, who designed the CYCLADES network, in an October 1973 note circulated to the International Network Working Group, which was published in a 1974 paper \"*A Proposal for Interconnecting Packet Switching Networks\"*. Pouzin was a pioneer of internetworking at a time when *network* meant what is now called a local area network. Catenet was the concept of linking these networks into a *network of networks* with specifications for compatibility of addressing and routing. The term was used in technical writing in the late 1970s and early 1980s, including in RFCs and IENs. Catenet was gradually displaced by the short-form of the term internetwork, *internet* (lower-case *i*), when the Internet Protocol spread more widely from the mid 1980s and the use of the term internet took on a broader sense and became well known in the 1990s.
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# Internetworking
## Interconnection of networks {#interconnection_of_networks}
Internetworking, a combination of the components *inter* (between) and *networking*, started as a way to connect disparate types of networking technology, but it became widespread through the developing need to connect two or more local area networks via some sort of wide area network.
To build an internetwork, the following are needed: A standardized scheme to address packets to any host on any participating network; a standardized protocol defining format and handling of transmitted packets; components interconnecting the participating networks by routing packets to their destinations based on standardized addresses.
Another type of interconnection of networks often occurs within enterprises at the link layer of the networking model, i.e. at the hardware-centric layer below the level of the TCP/IP logical interfaces. Such interconnection is accomplished with network bridges and network switches. This is sometimes incorrectly termed internetworking, but the resulting system is simply a larger, single subnetwork, and no internetworking protocol, such as Internet Protocol, is required to traverse these devices. However, a single computer network may be converted into an internetwork by dividing the network into segments and logically dividing the segment traffic with routers and having an internetworking software layer that applications employ.
The Internet Protocol is designed to provide an unreliable (not guaranteed) packet service across the network. The architecture avoids intermediate network elements maintaining any state of the network. Instead, this function is assigned to the endpoints of each communication session. To transfer data reliably, applications must utilize an appropriate transport layer protocol, such as Transmission Control Protocol (TCP), which provides a reliable stream. Some applications use a simpler, connection-less transport protocol, User Datagram Protocol (UDP), for tasks which do not require reliable delivery of data or that require real-time service, such as video streaming or voice chat.
## Networking models {#networking_models}
Two architectural models are commonly used to describe the protocols and methods used in internetworking. The Open System Interconnection (OSI) reference model was developed under the auspices of the International Organization for Standardization (ISO) and provides a rigorous description for layering protocol functions from the underlying hardware to the software interface concepts in user applications. Internetworking is implemented in the Network Layer (Layer 3) of the model.
The Internet Protocol Suite, also known as the TCP/IP model, was not designed to conform to the OSI model and does not refer to it in any of the normative specifications in Request for Comments and Internet standards. Despite similar appearance as a layered model, it has a much less rigorous, loosely defined architecture that concerns itself only with the aspects of the style of networking in its own historical provenance. It assumes the availability of any suitable hardware infrastructure, without discussing hardware-specific low-level interfaces, and that a host has access to this local network to which it is connected via a link layer interface.
For a period in the late 1980s and early 1990s, the network engineering community was polarized over the implementation of competing protocol suites, commonly known as the Protocol Wars. It was unclear which of the OSI model and the Internet protocol suite would result in the best and most robust computer networks
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# Instruction register
In computing, the **instruction register** (**IR**) or **current instruction register** (**CIR**) is the part of a CPU\'s control unit that holds the instruction currently being executed or decoded. In simple processors, each instruction to be executed is loaded into the instruction register, which holds it while it is decoded, prepared and ultimately executed, which can take several steps.
Some of the complicated processors use a pipeline of instruction registers where each stage of the pipeline does part of the decoding, preparation or execution and then passes it to the next stage for its step. Modern processors can even do some of the steps out of order as decoding on several instructions is done in parallel.
Decoding the op-code in the instruction register includes determining the instruction, determining where its operands are in memory, retrieving the operands from memory, allocating processor resources to execute the command (in super scalar processors), etc.
The output of the IR is available to control circuits, which generate the timing signals that control the various processing elements involved in executing the instruction.
In the instruction cycle, the instruction is loaded into the instruction register after the processor fetches it from the memory location pointed to by the program counter
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# International Data Encryption Algorithm
In cryptography, the **International Data Encryption Algorithm** (**IDEA**), originally called **Improved Proposed Encryption Standard** (**IPES**), is a symmetric-key block cipher designed by James Massey of ETH Zurich and Xuejia Lai and was first described in 1991. The algorithm was intended as a replacement for the Data Encryption Standard (DES). IDEA is a minor revision of an earlier cipher, the Proposed Encryption Standard (PES).
The cipher was designed under a research contract with the Hasler Foundation, which became part of Ascom-Tech AG. The cipher was patented in a number of countries but was freely available for non-commercial use. The name \"IDEA\" is also a trademark. The last patents expired in 2012, and IDEA is now patent-free and thus completely free for all uses.
IDEA was used in Pretty Good Privacy (PGP) v2.0 and was incorporated after the original cipher used in v1.0, BassOmatic, was found to be insecure. IDEA is an optional algorithm in the OpenPGP standard.
## Operation
IDEA operates on 64-bit blocks using a 128-bit key and consists of a series of 8 identical transformations (a *round*, see the illustration) and an output transformation (the *half-round*). The processes for encryption and decryption are similar. IDEA derives much of its security by interleaving operations from different groups --- modular addition and multiplication, and bitwise eXclusive OR (XOR) --- which are algebraically \"incompatible\" in some sense. In more detail, these operators, which all deal with 16-bit quantities, are:
- Bitwise XOR (exclusive OR) (denoted with a blue circled plus `{{fontcolor|blue|⊕}}`{=mediawiki}).
- Addition modulo 2^16^ (denoted with a green boxed plus `{{fontcolor|#0F0|⊞}}`{=mediawiki}).
- Multiplication modulo 2^16^ + 1, where the all-zero word (0x0000) in inputs is interpreted as 2^16^, and 2^16^ in output is interpreted as the all-zero word (0x0000) (denoted by a red circled dot `{{fontcolor|red|⊙}}`{=mediawiki}).
After the 8 rounds comes a final "half-round", the output transformation illustrated below (the swap of the middle two values cancels out the swap at the end of the last round, so that there is no net swap):
:
### Structure
The overall structure of IDEA follows the Lai--Massey scheme. XOR is used for both subtraction and addition. IDEA uses a key-dependent half-round function. To work with 16-bit words (meaning 4 inputs instead of 2 for the 64-bit block size), IDEA uses the Lai--Massey scheme twice in parallel, with the two parallel round functions being interwoven with each other. To ensure sufficient diffusion, two of the sub-blocks are swapped after each round.
### Key schedule {#key_schedule}
Each round uses 6 16-bit sub-keys, while the half-round uses 4, a total of 52 for 8.5 rounds. The first 8 sub-keys are extracted directly from the key, with K1 from the first round being the lower 16 bits; further groups of 8 keys are created by rotating the main key left 25 bits between each group of 8. This means that it is rotated less than once per round, on average, for a total of 6 rotations.
### Decryption
Decryption works like encryption, but the order of the round keys is inverted, and the subkeys for the odd rounds are inversed. For instance, the values of subkeys K1--K4 are replaced by the inverse of K49--K52 for the respective group operation, K5 and K6 of each group should be replaced by K47 and K48 for decryption.
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