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yn4r3
|
Which historical text, from any point in time, that we are aware of but not in possession of would be of greatest value to mankind if it were to be suddenly found?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/yn4r3/which_historical_text_from_any_point_in_time_that/
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"The recipe for Greek fire would be pretty cool.\n_URL_0_",
"The [Q document](_URL_0_) (a hypothesized early record of Jesus's teachings used as a source by the gospel writers) would be of enormous religious and cultural significance if an extant copy ever turned up.\n\nEdit: This is a pretty interesting shot at a reconstruction of what Q might have looked like: [The *Logia*](_URL_1_).",
"I doubt it would benefit mankind all that much, but I desperately want aristotle's histories of the constitutions of the greek city states besides athens back. ",
"3 choices:\n\n1. The works of Titus Livius aka Livy. His book, Ab Urbe Condita or the History of Rome, takes the city from the foundations under Romulus all the way to the death of Germanicus, proposed successor to the emperor Tiberius. Of the 142 \"books\" (see long chapters) only 35 survive, only from the early republican to early \"imperial\" (by this I mean the construction of the physical empire, not the political revolution which would breed Augustus). Notably missing is the second Punic War, which is poorly recorded as it is. Say what you want about Livy, but he was a solid source toting the \"party line\". Having the full works would also fully show us Livy's perspective in writing the editions.\n\n2. Along the same line, is the Biographies of Plutarch. While these works exist in a fairly complete manner. Of what we DONT have is his biography of Publius Cornelius Scipio Africanus, the man who defeated Hannibal. The war-hero, after the famous war, was crucified politically for, what Ive always read about the charges leveled against him (especially out of Livy :P) was murky at best. This alternate perspective would be interesting to have on such an important Roman hero. \n\n3. A little different, and an interesting point of fact: No work still exists which presents a negative opinion of the lauded philosopher Socrates. He was executed for crimes against the state, so there were some powerful people who *didnt* think he was the bees knees. All we know is what was left from Plato (the most famous and prominent source on Socrates, *who used him as a pen name in his philosophical works*) and several other pro-Socratic contemporaries. It would be interesting to see what other people thought about him, and maybe wed find out some interesting things about the second most important man in western philosophy. ",
"The Library of Alexandria....I know that's alot of books, not just one - but imagine all that ancient information!",
"Charthegenian litterature would have been a really nice addition to our world viwe. Its known that the chartehgenians had an extensive litterary tradition, but only a faction still exist throug greek and roman renditions. The travels of the charthegenian explorer Hanno to south africa just as an example",
"*Love's Labours Won* would be wonderful to recover. Given the inestimable formative impact that pretty much every other play by Shakespeare has had on English and Western culture as a whole, finding one of the \"lost plays\" would be incredibly valuable.",
"[All the suggestions and more from Cracked. It's actually very insightful and humourous.](_URL_0_)",
"The mountains of Aztec (Maya?) scrolls that burned for 3 days when put to the torch. The Alexandria of the Americas, all the more precious because only 3 books remain from the entire continent. ",
"Gorgias' \"On Nature or the Non-Existent\".\n\nProdicus' \"On Propriety of Language\".\n\nHeraclitus' refutation of the Principle of non-Contradiction.\n\nProtagorus' \"On Truth\".\n\nI'm choosing those because what references we have makes them seem...naive. But who knows what kind of philosophies we'd hold if Aristotle or Plato had been trash-canned in their favour.\n\nAnd given I subscribe to \"The philosophy of today is the common sense of tomorrow\" (loosely) that's fascinating. What we're left with is biased quips and dismissals. But who knows, maybe those forgottens were rigourous? And if they were...!",
"the book of eve",
"According to a PBS documentary series I saw some years ago about the history of China, when a new empire was established, the \"official histories' of the conquered empire would be burned and palace historians given the task of re-writing history in a way that represented the new regime in a favorable light.\n\nChina was not the only place where this kind of thing was done either by any means.\n\nIn the times when cities who lost wars were completely destroyed, that probably meant the records too, so there are probably many places we know nothing about whose writing all went up in flames.\n\nConsidering that 'official histories' might usually be filled with tedious propaganda and/or laden with mundane record keeping - it may or may not be a great loss, but we'll never know.\n\n",
"Slightly related but a question:\n\nThere was a history book in the great library before it burnt down that Carl Sagan talks about in his TV series. It apparently contained a bunch of history about the ancient world, including something like 10,000 years of history from before the Sumerian empire. Any idea what the title of this book was?",
"I don't know if this would be historically significant (and I'm no historian) but personally I would love if someone ever discovered [Claudius'](_URL_0_) lost histories and autobiography, if only to get his perspective on his relatives. ",
"I can't believe that no one has mentioned it: how about a real, authentic copy of the original Bible? There are literally thousands of versions with typos, mistranslations, intentional changes made by scribes, but we don't know what the actual text was originally.\n\nConsidering that there are cults and entire religious denominations that were founded based on a single sentence in the book, it would be nice to have an authentic copy.\n\nHere is a Stanford lecture on this issue:\n_URL_0_",
"Aristotle's Poetics, Book II",
"It's not of greatest value to mankind, but the Greek writer Posidonius wrote an ethnography on the Gauls, upon which pretty much every subsequent work dealing with the Gauls was based (even information in Caesar's *Conquest of Gaul*). This ethnography, along with everything else Posidonius wrote, exists only in fragments quoted by later writers. Given that the ancient Celtic speaking peoples of Europe didn't really write anything about themselves down, finding an extant copy of this work would be fascinating.",
"In addition to all the ancient texts already mentioned, are any of the texts burned by the Nazi's considered 'lost'?\n\nFurther, I recall seeing or hearing something about comics being destroyed in the mid-20th century, but I can't find any references to it. Can someone elaborate on the scale of this episode and what might have been lost?",
"Anything from the Library of Alexandrea just before the \"accidental\" fire.",
"I learned so much in this thread alone, about so many different cultures. This was an awesome question to ask. Thank you. :)",
"Lost cantatas of J. S. Bach!",
"I'm no history buff but I'm pretty sure the dead sea scrolls would mean a bit.",
"This thread made me sad about how much human knowledge and records were lost.",
"How about Claudius's 20-volume history of the Etruscans including a dictionary of the Etruscan language?",
"Tablets from Sumer and ancient Egypt. We actually know very little about these civilisations. The Hindus civilisation text as well. ",
"Aristotles Second book on Comedy."
]
}
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[] |
[] |
[
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"http://en.wikipedia.org/wiki/Greek_fire"
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[
"http://en.wikipedia.org/wiki/Q_source",
"http://homepage.virgin.net/ron.price/syno_sQet.html"
],
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[],
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"http://www.cracked.com/article/18368_7-books-we-lost-to-history-that-would-have-changed-world/"
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[],
[],
[],
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"http://en.wikipedia.org/wiki/Claudius#Scholarly_works_and_their_impact"
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"http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CD8QtwIwAA&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DogG38VaSG3I&ei=Apw1UILcGo7orQf8roDICg&usg=AFQjCNHsDd70TNcYVle09kNZGBCoAFcrtQ&sig2=24re3aFNZMdp0vEO0rUdPQ"
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65839o
|
If acoustic energy is converted to heat when a material absorbs sound, is it possible for an audio source to produce enough acoustic energy to ignite something?
|
Obviously this isn't a problem even at the loudest of concerts, but would it be possible to concentrate or focus enough acoustic energy onto an object to ignite it? Would the frequency of the audio make a difference?
|
askscience
|
https://www.reddit.com/r/askscience/comments/65839o/if_acoustic_energy_is_converted_to_heat_when_a/
|
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"It IS possible, though as you said yourself highly\nimprobable. Sound is simply the vibration of particles in the air (hence why there's no sound in space) and that vibration hits and object and can vibrate it or induce heat, which is why you can break glass with a sound (not the only reason, mind you). If you played a sound at a certain frequency or amplitude (loudness) you could light something on fire, that said your speaker would light on fire long before due to the way they work (which is another question entirely)."
]
}
|
[] |
[] |
[
[]
] |
|
2w0bla
|
What was the input of the Polish people in the second WW? How did they contribute.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2w0bla/what_was_the_input_of_the_polish_people_in_the/
|
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"Here's a brief answer:\n\nBefore the war Polish agents passed to the British an Enigma machine, which enables the British to be aware of how it worked even if its possession did not solve the problem of how to break German codes.\n\nPolish units and individuals escaped to the West in 1940. Many pilots joined the French Air Force and then the Royal Air Force, proving highly effective and successful from the Battle of Britain (where a Polish squadron was the most successful) onward. There were also Polish squadrons in Bomber Command.\n\nPolish research into paratroops was passed on to the British (who had done almost no work in the area) and things like the basic parachute harness were of Polish design. Polish paras were trained and used alongside British in 1944 at Arnhem. The British raised a Polish armoured division and other army units. This division fought with distinction on the shoulder of the Falaise pocket in 1944, holding despite desperate assault by fanatical SS troops trying to break out of the Allied encirclement. Many Poles fought in Italy.\n\nThe Soviet Union, despite massacring the 1939 Polish leadership at Katyn Forest, saw advantages in raising their own Polish units, which were officered by Russians given Polish identities. The Soviet commander Rokossovssky was Polish.\n\nIn 1944 Polish nationalists rebelled against their German overseers in Warsaw, as the Red Army approached. The Red Army halted on the Vistula River and the Germans had several weeks to put down the uprising in the most brutal fashion. Stalin also resisted Western, in particular British attempts to air drop supplies and weapons to the Poles.\n\nIt is also something of a myth that the Poles fought incompetently in 1939. They did not charge tanks with massed cavalry (in Polish terrain cavalry made some sense the Red Army used cavalry divisions there in 1944), and they would have cost the Germans quite dearly had not the Soviets surprise invasion of their rear forced them into surrender. Many German units suffered grievous casualties in Poland."
]
}
|
[] |
[] |
[
[]
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||
4mzbwd
|
How strong is the link between benzodiazepines and dementia/Alzheimer's? What about marijuana?
|
I've seen information before that indicated that an individual taking benzo's over a long period of time opens themselves up to additional risk to cognitive disorders, and I'm just hoping to get the community's perspective on the subject. Is this true? If so why?
Also, I remember reading that marijuana use has a negative correlation with those types of cognitive disorders? If this is true, is it because of the dopamine involved? If not, why?
Thanks for any and all replies!
|
askscience
|
https://www.reddit.com/r/askscience/comments/4mzbwd/how_strong_is_the_link_between_benzodiazepines/
|
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"text": [
"Tried looking up a few studies for you. A retrospective study in France found that in those with dementia, there was a higher rate of exposure to psychotropic and anti-psychotic drugs, with anti-psychotic exposure having the highest association with dementia. Hypnotics/anxiolytics such as benzodiazepines carried a lower relative risk (1.74 risk ratio vs. 6.44 risk ratio for anti-psychotics). A prospective study from Washington that began in 2004 found no meaningful increased incidence of dementia in those exposed to benzodiazepines. It seems that the link between benzodiazepine use and dementia is not too compelling. \n\nI wasn't able to find any reasonable articles that investigate a link between long-term cannabis use and dementia, although I'm sure this is being investigated. There are some papers out there about pilot projects investigating the use of medical cannabis oil to treat symptoms of dementia which have found promising results, but of course this does not prove any protective effects of cannabis with regards to dementia. But until cannabis is completely legalized, research in the area will be stifled.\n\nBreining A, Bonnet-zamponi D, Zerah L, et al. Exposure to psychotropics in the French older population living with dementia: a nationwide population-based study. Int J Geriatr Psychiatry. 2016\n\nGray SL, Dublin S, Yu O, et al. Benzodiazepine use and risk of incident dementia or cognitive decline: prospective population based study. BMJ. 2016;352:i90."
]
}
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[] |
[] |
[
[]
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|
jxjle
|
What would you see from inside the event horizon of a singularity?
|
Relating to [this paper](_URL_0_) about things orbiting inside black holes without hitting the singularity. Putting aside the feasibility of intelligent life existing within the event horizon, how would the rest of the universe appear to them from the other side of the event horizon? (Or rather, how would it be different to what we see from Earth?) Would there be some kind of lensing effect from the gravity, red/blue shift, etc? Thanks.
|
askscience
|
http://www.reddit.com/r/askscience/comments/jxjle/what_would_you_see_from_inside_the_event_horizon/
|
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"text": [
"RobotRollCall has the answers you seek.\n\n_URL_0_",
"Something like this [A Journey into a Black Hole\n](_URL_0_)\t",
"RobotRollCall has the answers you seek.\n\n_URL_0_",
"Something like this [A Journey into a Black Hole\n](_URL_0_)\t"
]
}
|
[] |
[
"http://arxiv.org/abs/1103.6140"
] |
[
[
"http://www.reddit.com/r/askscience/comments/f1lgu/what_would_happen_if_the_event_horizons_of_two/c1cuiyw"
],
[
"http://www.youtube.com/watch?v=eI9CvipHl_c"
],
[
"http://www.reddit.com/r/askscience/comments/f1lgu/what_would_happen_if_the_event_horizons_of_two/c1cuiyw"
],
[
"http://www.youtube.com/watch?v=eI9CvipHl_c"
]
] |
|
btfh0t
|
what is the difference nutritionally between artificial and natural sugars, like why are the sugars from my apple any better for me than the sugars from my apple lollipop if it’s all still sugar?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/btfh0t/eli5_what_is_the_difference_nutritionally_between/
|
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"There is no difference between 'artificial' and 'natural' sugars, they are the same. \n\nThe important difference is that when you eat a lollipop it might contain more sugar than the apple does and you certainly wouldn't eat ten apples but you could easily eat ten lollipops (in a relatively short period).\n\n & #x200B;\n\nSidenote: Sugar and sugars don't mean the same. When we say sugar we usually mean that type of household sugar you use for baking which is sucrose. Sugars usually refers to carbohydrates in general which is a class of different compounds including sucrose, glucose, fructose (an apple contains some amount of all three) , lactose, etc.",
"Well there's not a chemical difference between the fructose in the apple and the fructose in the lollipop. There are two reasons the apple is better for you. 1. The apple has some vitamin C and probably others 2. The apple has dietary fiber and other complex carbs, which will lead to a smoother blood sugar curve than if you ate the same number of calories in lollipop form."
]
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[] |
[] |
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1qzjrl
|
What is the smallest particle our skin can feel?
|
So I was walking on a cloudy day and I noticed that before raining, most of the times, I feel the slightest amount of water. This is so tiny I cannot see it, but my skin does sense it.
What would be the smallest quantity of atoms our epidermis can feel?
Note: I have a general understanding that our skin has different sensitivity in different areas, so I would propose the question with the most common skin parts to be bare in the air (ie: hands, arms, neck, face).
|
askscience
|
http://www.reddit.com/r/askscience/comments/1qzjrl/what_is_the_smallest_particle_our_skin_can_feel/
|
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"On the fingertip, you can sense the orthogonal displacement of your skin with a detection threshold of roughly 25 microns at 0.5 Hz (a 2 second smooth displacement). At 60 Hz for a half second that threshold is under 10 microns, and it drops to 1-2 microns at 250-300 Hz. \n \nFor movement parallel to the surface of the skin, stimuli a few orders of magnitude smaller (around 10 nm) can be detected simply because they drag the skin from side to side. \n_URL_0_ \n \nOf course, based on this 1999 study published in the Journal of Neurophysiology, scientists created another study to demonstrate the same level of sensitivity and published their results in Nature. And the reviewers must have been very ignorant not to notice this.",
"A very good article was published recently in Nature on the topic of the limit of our [tactile perception](_URL_0_). Interestingly it was found that our sense of touch is sufficiently sensitive to detect nanoscale surface features as small as 10nm. ",
"I was thinking that the rain drop phenomenon was a perception of heat energy, i.e the small drops rapidly cooled a spot of skin and you are detecting the heat loss not the physical size of the object.\n\nSo I went to google smallest temperature difference skin can perceive and accidentally found [this](_URL_0_) research showing how skin temperature affects the perception of roughness."
]
}
|
[] |
[] |
[
[
"http://jn.physiology.org/content/81/4/1548.short"
],
[
"http://www.nature.com/srep/2013/130912/srep02617/full/srep02617.html"
],
[
"http://psycserver.psyc.queensu.ca/lederman/013.pdf"
]
] |
|
fzta9q
|
why does long division work?
|
I understand how to do long division but just can’t see why it should work. Who invented it and how?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/fzta9q/eli5_why_does_long_division_work/
|
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"Think of it a bit like you first learned division, sharing something out, but what you are sharing has a number if different size parts. You put aside the small stuff and share out as many of the big ones as you can. You take the left over big bits and break them into smaller pieces and add in the parts you set aside that are the same size, share out as many as you can. Repeat as necessary.\n\nThe big bits are the numbers on the left of the dividend, breaking into smaller parts is moving one place to the right and bringing down the next digit, effectively multiplying the remainder from each stage by ten.\n\nAs to who invented it, I'm going to guess Arab/Indian scholars as it needs place notation and the zero to work. It's possible the Chinese had something similar using an abacus. The ancient Egyptians had something similar but used smaller and smaller unitary fractions (1/x) rather than powers of ten to share out the successive remainders.",
"Lets do 123/5 with the same steps as in long division but in more rigorous fashion.\n\n123 can be written as 1×100 + 2×10 + 3×1 (or with exponents as 1×10^2 + 2×10^1 + 3×10^(0). We'll need this later).\n\nSo now we have ( 1×100 + 2×10 + 3×1 ) / 5.\n\nWe can write this as\n\n( 1×100 ) / 5 + ( 2×10 ) / 5 + ( 3×1 ) / 5\n\nAnd further.\n\n1/5 × 100 + 2/5 × 10 + 3/5 × 1\n\nNow we can start doing the divisions.\n\n1/5 would result in some fraction. We do not accept any fractions here. So lets go back few steps and combine the 100 term and 10 terms together.\n\n( 1×100 + 2×10 + 3×1 ) / 5 = ( 12×10 + 3×1 ) / 5. = 12/5 × 10 + 3/5 × 1\n\n12/5 is 2 and leftover 2/5 so. Lets keep the 2 here and move the leftover to the next term. So 12/5 ×10 = 2×10 + 2/5×10.\n\n12/5 × 10 + 3/5 × 1 = 2×10 + 2/5 × 10 + 3/5 ×1 = 2×10 + 23/5 × 1\n\n23/5 is 4 and 3/5 as leftover. \n\n2×10 + 23/5 × 1 = 2×10 + 4×1 + 3/5 × 1\n\nAgain lets keep the 4 here and move 3/5 to the next term. \nBut we do not have any terms left? We can just add more.\n\nAt the beginnign we wrote the number using decreasing powers of 10 (10^(2), 10^(1), 10^(0)). So we can just add 0×10^-1 (=0×0.1) in there! (it is just zero, we can add zeros to number as many as we like)\n\n2×10 + 4×1 + 3/5 × 1 + 0×10^-1 = 2×10 + 4×1 + 30/5 ×10^-1\n\n30/5 is nice even 6.\n\nSo our result is \n\n2×10 + 4×1 + 6 ×10^-1\n\nNow we just turn this back into normal number.\n\n24.6\n\nLong division does these steps. (lets see how long division works with reddit formatting...)\n\n 5|123\n -0 5 doesn't go into 1.\n 12 carry the 1 to the next term.\n -10 5 goes into 12 2 times. 2×10 goes into the result so remove 2×5 from here.\n 23 And carry the remaining 2 to next term.\n -20 5 goes into 23 4 times. 4×1 goes to the result so remove the 4×5 from here.\n 30 And carry the remaining 3 to the next term.\n -30 5 goes into 30 6 times. 6×0.1 goes to the result so remove the 6×5 from here.\n 00 No more remainders to carry so we are done.\n Result is 2×10 + 4×1 + 6×0.1"
]
}
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[] |
[] |
[
[],
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|
3568vx
|
What are the exact criteria with which historians can consider a past event to be a historical fact?
|
Hello, I am interested in knowing more about how historians ascertain past events as a fact. I've read some stuff about historical relativism, and I would like to know what criteria historians commonly agree on when debating whether something happened or not.
I'm interested in things like thresholds. E.g., if we say that person a murdered person b, and there is one eyewitness. In that case even judges can have a hard time ascertaining the truth. What if there are ten witnesses though, or hundred, or thousands? At what point is there a threshold that is crossed and after which we can say with conviction that the overlapping witness reports represent a fact, and how would these thresholds be characterized? Couldn't these witnesses all be lying though, and how would a historian refute a denialist argument that those eyewitnesses are lying or are part of a conspiracy and so on?
I would basically like to know what criteria a past event (or the documents, sources, relics etc. OF that event) have to meet in order for the event to be considered a historical fact.
In particular I'd be grateful to get some reading recommendations from a philosophical perspective. Certainly there must be some hallmark texts that deal with this? I've tried to look into some books about analytical philosophy of history, but I find it hard to get answers. Thanks for your time.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/3568vx/what_are_the_exact_criteria_with_which_historians/
|
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"Let me start by proposing that history is not a mere pile of facts that we prove or disprove one by one and add to the pile. There are many things that may or may not have happened, but we can still learn lots from them. \n\nA great example of this is in the book by Alfred Fabian Young, *The Shoemaker and the Tea Party: Memory and the American Revolution* (Boston, Mass.: Beacon Press, 1999). Young looks at the memories and tales told by George Robert Twelves Hewes about his role in the event that came to be known as \"the Boston Tea Party.\" To pick one example of many in the book, Hewes claims that he worked shoulder to shoulder dumping tea overboard with the great Samuel Adams and John Hancock. While history seems to indicate that John Hancock was NOT actually involved in the physical dumping, it is unclear about where Adams was. Now, Young could have given up writing the book because he couldn't establish Hewes' memories as fact, but instead he uses the stories to illustrate how the rhetoric and ideology of the revolution infused Hewes' memory -- and to show what resonated with his eagerly listening audiences in the 1820s as he told his tales. Young reveals a story about the promise of egalitarian democracy and freedom from class bondages in Hewes' memories; and in that story, the question of the 'facts' of the Boston Tea Party is almost totally irrelevant.\n\n > \"Ideology did not set Georges Hewes apart from Samuel Adams or John Hancock. The difference lies in what the Revolution did to him as a person. His experiences transformed him, giving him a sense of citizenship and personal worth. Adams and Hancock began with both. [...] John Hancock and George Hewes breaking open the same chest at the Tea Partty remained for Hewes a symbol of a moment of equality.\"\n\n\nI'll end by eloquently copy-pasting something I posted in another thread recently:\n\nBasically, I think every historian comes to their own philosophy/epistemology/ontology of the past (how can we know what we know; what does exist and in what forms). However, there are certain broad movements in theory that basically set a standard for the field, upon which contemporary practitioners usually practice variations. (E.G. Post-modernism) If you are interested in reading scholars' various takes on the topic, two short and simple reads (if outdated!)that are good to start your journey with are:\n\n* Marc Bloch, *The Historian’s Craft* (New York: Knopf, 1953)\n* Edward Hallett Carr, *What Is History?* (New York: Knopf, 1962).\n\nHeavier reads include:\n\n* Peter Novick, *That Noble Dream: The “Objectivity Question” and the American Historical Profession* (Cambridge University Press, 1988).\n* Gabrielle M. Spiegel, “The Task of the Historian,” *The American Historical Review* 114, no. 1 (2009): 1–15, doi:10.1086/ahr.114.1.1.",
"I think one important point to make is that historians rarely speak in absolutes. I am a great fan of the \"In Our Time\" radio show/podcast, which chooses one topic, per episode, from the fields of history, science, religion, etc, and invites a panel of experts to discuss it. Many of these experts are pioneers in their field, and almost without exception they are professors/lecturers/researchers. The only term heard more frequently than the host's indroductory \"hello\" is \"the sources tell us...\". Even with archaeological corroboration, there aren't many things that are treated as \"facts\"",
"I can give a perspective from archaeology, because we deal with this all the time also. We have lots of \"facts\" in that I can see the remains of a building or hold a pot in my hands, but what those mean is very much an interpretive effort and so establishing facts based on those material things is a hugely difficult task. \n\nThe first thing they teach you in archaeology is that context is everything. A single wall doesn't really tell you much. A single fork doesn't tell you much. It is the association of an object in relation to all the other objects around it that give it meaning and allow us to interpret it. \n\nIt is really just an extension of what you do in your everyday life. How do you know which doors you should or should not walk through? You use contextual clues about whether the door is open or closed, locked or unlocked, clear or opaque, where in a building it is, signs hung around it, and what rooms it has access to. That it is a door really doesn't tell you much about it unless you have that contextual information. \n\nWe establish a lot of archaeological \"facts\" based on this contextual information as it reoccurs in multiple instances. A basic archaeological fact would be a chronology of pottery types. So, for instance, two or three pottery types might have been made for two or three hundred years before being replaced with two or three different types of pottery. We know this as a \"fact\" because we only ever find those first three types at archaeological sites in context together, and the second three in context together, but never a mixing of the two. This is very simplified, and it pretty much always messier than the example I'm giving, but that relates the idea at least. \n\nOf course, it isn't so easy, and there is a huge amount of literature discussing how to interpret the archaeological record and establish what we do and do not know about an archaeological site. For instance, how do we know that a pot we found in a room was actually used by people living in that room or if it was put there by someone else when the room was abandoned. That is a very basic archaeological question that is fairly easy to answer (but perhaps more complicated than you would think), but these are the sort of \"taphonomic\" issues we have to deal with all the time. Basically, how did the artifacts we are looking at end up where they ended up. This is really important because it totally changes the way we interpret them. For instance, if I were to go into my kitchen right now I would find pots and pans in the cupboards and under the sink. The odds that I go into the kitchen and find them being used on the stove are much smaller than finding them in storage. If I didn't think critically about the situation and the contextual information, I might come to the reasonable conclusion that the person who uses that kitchen cooks their meals under the sink. Of course that is preposterous, but that is why archaeologists spend a lot of time talking about how to interpret material remains without knowing what they are a priori. \n\nThen there is the question of interpreting these artifacts and places once we have a pretty good idea of how they were used. In other words, why do we care that you cook on the stove and not under the sink? The tricky part here is that, unlike historical documents, archaeologists have a very hard time talking about specific events. I can't really tell you much about how one person used this particular cooking pot, but I can probably tell you about how a whole population of people used these very similar cooking pots for similar activities. \n\nFor the most part, archaeology can't tell you much about individuals, but it can tell you a lot about populations and what people are doing in aggregate. We can say something about an individual artifact, but I don't think any archaeologist is going to claim there are many instances were one artifact can establish some historical \"fact\". It is only by looking at large numbers of artifacts and comparing with each other that we can say with some certainty that our interpretation is a \"fact\". For example, if a particular type of building with images of a particular deity show up in the same places in multiple villages, we can say with pretty good certainty that people in that region worshiped this deity in that kind of religious building. We can even potentially say that about villages we haven't excavated, because our sample is so large. Of course there are always exceptions, but the more evidence we have and the more similar it all is to each other, the more sure we can be of how \"factual\" something is. \n\nWe also have another criteria for establishing an archaeological fact in addition to having a large sample. Generally, we like to see *multiple lines of evidence* to really solidly establish something as fact. Basically, if we reach the same interpretation from different kinds of evidence, that strengthens the reliability of that interpretation. So, maybe we can say that it is a fact that people in region #1 were trading with people in region #2. We might be able to say that because we find two different styles of pottery in both regions and we have figured out that one kind is made in region #1 and the other kind is made in region #2. That is pretty compelling, but what if we find that shell jewelry made from a particular type of marine shell is found in both regions, but only the people in region #1 are actually by the sea and can access that shell. That is also evidence for trade between the two regions, but both together really strengthen the whole argument. I could say that potentially the people in Region #2 were going down to the coast to get shell for themselves and not trading with Region #1, but if we add in the ceramic evidence it supports trading between the two. \n\nBasically, we can never really know something as \"fact\" in archaeology or history because we can't directly observe what happened, but we can say that certain things are more likely than others. I'm not going to argue that pyramids *couldn't* have been built by aliens, but given everything else we know (the multiple lines of evidence and the context here), it is incredibly unlikely that is the case. The *most reasonable* and most well supported answer is what we generally consider archaeological fact, even if there is always some ambiguity about what exactly happened. \n\nEdit: Going to echo the \"history isn't a pile of facts\". Same with archaeology. Yeah, we spend a lot of time just establishing what people did and when, but the interesting part comes in interpreting the why. "
]
}
|
[] |
[] |
[
[],
[],
[]
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|
6c9s7u
|
why does the healed skin on my wounds have the same patterns, wrinkles and creases as before?
|
I had to cauterize a rather big area on my pinky finger. After 2-3 weeks the skin is healed almost completely, but it seems strange to me that it has the same "imperfections" as the surrounding skin (creases, wrinkles, lines).
Why isn't the healed skin scar tissue? (smooth and without almost any marks)
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6c9s7u/eli5_why_does_the_healed_skin_on_my_wounds_have/
|
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"Because the skin there is constantly being crushed and stretched, resulting in it becoming wrinkled. If it was pure scar tissue it would rip when you tensed your tendons. ",
"Look at your hand, now move the inside of the base of your thumb towards your pinky. See all the folds and such? Your skin will fold the same way even after scarring.\n\nAnother example is that I game about as often as someone with a fulltime job is at work (30ish hours a week) my hand positioning presses the pinky side of my palm into my desk, causing a unique fold that wasn't there just a few years ago. If I sliced that part of my hand up (or burned it) the healed skin wont have those creases and wrinkles, but will develop them again as I continue to hold that unique hand position.\n",
"When you have a wound, it's usually only the top layer of the skin that gets damaged. The wrinkles and creases however come from the deepest layers of the skin. \n\nSo the skin that grows back grows onto the same creases - they haven't gone anywhere. If you were to have a wound so bad that your skin is gone completely, the creases would be gone or at least different. "
]
}
|
[] |
[] |
[
[],
[],
[]
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|
27xsco
|
Are hydrogen and oxygen molecules constantly forming new liquid water, or has all the water that can exist on earth already been formed?
|
askscience
|
http://www.reddit.com/r/askscience/comments/27xsco/are_hydrogen_and_oxygen_molecules_constantly/
|
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"Water is continually being created and destroyed by a number of natural processes. Probably the two fastest are the HOx cycle in the atmosphere:\n\nO3 + photon ( < 300 nm wavelength) = > O2 + O(1D)\nO(1D) + H2O = > 2OH\nOH + organic compd. = > H2O + products\n\nand photosynthesis:\n\nxCO2 + xH2O = > (CHO)x + xO2\nan example of this is where x is 5 or 6, and (CHO)x denotes a carbohydrate "
]
}
|
[] |
[] |
[
[]
] |
||
lnifv
|
If the moon is spinning, why do we always see the same face?
|
How can it be so perfectly in sync with it's orbit around the earth? This seems so unlikely as to be impossible. Is there a "heavy" side of the moon that has been pulled toward the earth and then stayed there?
|
askscience
|
http://www.reddit.com/r/askscience/comments/lnifv/if_the_moon_is_spinning_why_do_we_always_see_the/
|
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"text": [
"It's due to a process called [tidal locking](_URL_0_). The same thing has happened in the Sun/Mercury system, ~~and if let go long enough, I believe it would happen with the Sun/Earth system as well.~~ *Edit: Actually, after thinking for a moment, I don't think that's true, but I'll leave it for someone more qualified to make any further assertions.*",
"It's called tidal locking. Gravitational force depends on the square of the distance. For objects that are close enough and big enough to us, there is a significant variance in the gravitational force on one side versus the gravitational force on the other side. The side of the moon facing us isn't heavier, but because it's closer, our gravity is stronger on that side. ",
"...and it's not entirely locked. it oscillates little bit. it's called \"moon libration\".",
"It's due to a process called [tidal locking](_URL_0_). The same thing has happened in the Sun/Mercury system, ~~and if let go long enough, I believe it would happen with the Sun/Earth system as well.~~ *Edit: Actually, after thinking for a moment, I don't think that's true, but I'll leave it for someone more qualified to make any further assertions.*",
"It's called tidal locking. Gravitational force depends on the square of the distance. For objects that are close enough and big enough to us, there is a significant variance in the gravitational force on one side versus the gravitational force on the other side. The side of the moon facing us isn't heavier, but because it's closer, our gravity is stronger on that side. ",
"...and it's not entirely locked. it oscillates little bit. it's called \"moon libration\"."
]
}
|
[] |
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[
[
"http://en.wikipedia.org/wiki/Tidal_locking"
],
[],
[],
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"http://en.wikipedia.org/wiki/Tidal_locking"
],
[],
[]
] |
|
bsk15c
|
How would soft drinks (Carbonated) behave in space?
|
I was watching a video the other day about how an astronaut invented a special drinking cup for liquids in space, and that gave me a question that lingered in my brain enough to ask here.
Basically, how do soft drinks, like Coke and Pepsi, act in space where there's no gravity? How do the bubbles form and where do they go? Does it pose any dangers? If left opened to the "air" in the space-station, would it become de-carbonated like here on Earth? or will it hold onto the gas in it..etc
(I wasn't sure if I should use Astronomy, Physics or Chemistry for this, sorry if I made the wrong call.)
|
askscience
|
https://www.reddit.com/r/askscience/comments/bsk15c/how_would_soft_drinks_carbonated_behave_in_space/
|
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"Here is a link to a video of alka seltzer in water in the space station. It looks like it behaves similarly to Earth just the bubbles don't float to the top and pop so they just sort of mix together and are held together by the surface tension of the water.\n\n_URL_0_",
"If a bottle of Coke were to be opened and a big enough volume were to be squeezed out, we'd see that the squeezed out soda would take on a near-spherical shape.\n\nThe bubbles would form and not really go anywhere; to actually \"pop\", they would have to form exactly at the surface of the sphere. So the bubbles would just accumulate until the dissolved CO2 turned into gaseous CO2, wherein it would pop depending on its position around/within the sphere. The sphere would expand a significant amount in volume and be more akin to froth than soda when it is done. This is because the bubbles stay where they are.\n\n_URL_0_\n\n_URL_1_",
"I remember a post on Reddit a while back about how both Coke and Pepsi had delivered soda to the ISS. Both times it ended in disaster because there isn't gravity to get the CO2 bubbles to rise up into a burp. Instead the gas stays in your stomach, accumulating, until you vomit it up. Along with a bunch of other liquid and solids. 🤮"
]
}
|
[] |
[] |
[
[
"https://youtu.be/bgC-ocnTTto"
],
[
"https://www.youtube.com/watch?v=DTN76YTB4eI",
"https://www.nasa.gov/audience/foreducators/5-8/features/F_Carbonated_Beverages_Space.html"
],
[]
] |
|
8n5ktp
|
why is it ok to pray to statues and pictures of jesus if there’s a commandment against graven images?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/8n5ktp/eli5_why_is_it_ok_to_pray_to_statues_and_pictures/
|
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"The commandment is to have no other God's not no pictures, in Catholicism. Islam forbids images because they worry about exactly what has happened in the Catholic Church before where the symbols and pictures became more....up front important for lack of a better way of putting it. Can't say it's a bad idea, just think it's a bit of a harsh punishment. ",
"I haven't been to church in 20-25 years but if I remember right it's because you aren't praying to the image of Jesus, but to Jesus himself while you happen to be in front of said image. ",
"When I became catholic, just recently mind you., I was taught that it is not idolatry because I don’t believe the statue of Jesus is God. It’s just a way to feel more intimate and have a focal point for your attention. "
]
}
|
[] |
[] |
[
[],
[],
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||
fm2cl5
|
How are scientists getting estimates of 40-80% of populations that will contract the Coronavirus?
|
askscience
|
https://www.reddit.com/r/askscience/comments/fm2cl5/how_are_scientists_getting_estimates_of_4080_of/
|
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"text": [
"one factor is that, once people are infected, they become (im simplifying) either dead or immune.\n\nthis means that, once this number goes over a certain critical percentage of the population, the disease cant really spread much further because you dont encounter other suceptible individuals that can catch it.",
"Herd immunity is the upper bound.\n\nFor measles, polio, and other prolific viruses its around 80%. This is what people with suppressed immune systems (who cant recieved vaccinations) depend on to prevent getting those viruses.\n\nHere's an article: _URL_0_\n\nBasically, it's the worst case scenario. 100% of the population wont get infected because eventually the amount of uninfected people are vastly outnumbered by those who have recovered already (and are thus immune due to developed antibodies). You cant infect somebody who was already infected.\n\nIf it gets bad enough that we rely on herd immunity, it's bad news. Hopefully social distancing is more effective.\n\nI work for a catastrophe modeler, and unfortunately if we hit herd immunity, we are looking at over 2 million deaths in the US alone.",
"A simplified explanation is that each person infects roughly 3 more persons. This is called the basic reproduction number(R0) and estimates vary. Therefore, when at least 2/3rds of the population are immune, each person will statistically only infect one person or less, thus stopping the spread.",
"Every virus has a property called \"The Basic Reproduction Number\" commonly abbreviated \"R0\" and pronounced \"R Naught.\" In simplest terms the value of R0 describes how contagious something is. A high R0 value indicates how rapidly it can spread throughout a new host, and the faster it can spread through a host the more easily it can then be transferred to more hosts. Using that value, it's then a probability game based on the density of a population. In a high density population, people experience more interactions, and every interaction has the risk of transferring the virus. Density alone doesn't paint a full picture though, if it did then a 100% infection rate would be inevitable for every virus over a long enough time span, and we know that's not the case. There's also models for how social networks form; within a larger population several sub-groups tend to form which have limited interactions between each other despite all living within the same area meaning the virus could die out within one sub-group and never transfer to a neighboring group. There's not a hard number for that last part though, so some assumptions have to be made about how \"communal\" a population is which produces a wide variety of possible outcomes."
]
}
|
[] |
[] |
[
[],
[
"https://www.google.com/amp/s/www.health.com/condition/infectious-diseases/coronavirus/herd-immunity%3famp=true"
],
[],
[]
] |
||
2zf21k
|
If the universe is constantly expanding, how will it ever be possible to have the same temperature at every single point in space?
|
Isn't there a law that says that eventually, the universe will be isothermic? Also I'm not implying that space is discrete, but by every single point I mean at any location in space.
|
askscience
|
http://www.reddit.com/r/askscience/comments/2zf21k/if_the_universe_is_constantly_expanding_how_will/
|
{
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"text": [
"First, there are two relevant laws of thermodynamics for your question:\n\nThe zeroth law of thermodynamics says that if object A is in thermal equilibrium with object B, and B is in thermal equilibrium object C, then A is in thermal equilibrium with C.\n\nThe second law of thermodynamics says that the entropy of an isolated system (such as the universe) can only increase over time. In the context of your question, this means that an isolated system will approach homogeneous thermal equilibrium.\n\nYou're on the right track with your thinking. The expansion of the Universe prevents thermal contact of distant regions of space. However, we know that the Universe was pretty darn small for a significant period of its early life, at least enough for thermal contact between opposite ends of the Universe to occur for some time. This works because one point of space comes to equilibrium with an adjacent point, and so on, so that a long chain of thermally equilibrated points can stretch from end to end of the Universe, thus by the zeroth law, the two ends approach equilibrium.\n\nSeveral experiments (COBE, WMAP, and recently Planck are the missions that come to mind) have been sent into space to observe the [cosmic microwave background radiation](_URL_0_), which is basically a measure of the average temperature of the universe at any given point in space. It is because of the CMB that we can say that the average temperature of the Universe is ~2.7 K. So by determining just how uniform the CMB is, we can get an idea of how quickly it expanded in the first seconds after the Big Bang (i.e., how much time opposite ends of the Universe had to be in equilibrium).\n\nAt first glance, the CMB seemed perfectly uniform. We had to send up better and better experiments to see just how perfect its uniformity was. Eventually, we did notice that the CMB is slightly anistropic with 1 part in 100,000. So the Universe is not even now in thermal equilibrium as a whole, and this has been the case since the inflationary period after the Big Bang.\n\nHowever, the Universe is also always increasing in entropy due to the second law. So regions of the Universe that are not in thermal contact will still run out of usable energy and regress to the temperature of the CMB in that local area. And, since the Universe will (presumably) continue to expand, the temperature of the CMB will asymptotically approach 0 K, and the Universe will be in thermal equilibrium (which gives the maximum entropy of a system). This concept of the Universe's fate is known as the [heat death of the Universe](_URL_1_)."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Cosmic_Microwave_Background",
"http://en.wikipedia.org/wiki/Heat_death_of_the_universe"
]
] |
|
2itr3y
|
Are there any instances of modern wars being won from a production disadvantage?
|
I read through the rules and the FAQ topics under "War". I hope I'm on the correct side of the "any X throughout history" rule, and that this topic is not a repeat.
My question stems from documentaries and books I've encountered about the US fighting Japan in WWII and about the American Civil War. In both cases, the winning side is generally said to have won because of their superior production capabilities making a big difference over the long term. Based on these instances, despite the differing strategies of Japan and the Confederacy, it seems as though production is an insurmountably dominant factor. I am wondering if this is a kind of rule, and if there are exceptions.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2itr3y/are_there_any_instances_of_modern_wars_being_won/
|
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"There's a few minor and debatable examples here and there; when Uganda invaded Tanzania in 1979, the Ugandans had an edge in terms of overall materiel, but were eventually ousted from Tanzanian territory after a counter-attack. The war was a short one, and the Tanzanians had great political allies plus a sympathetic 'hostile' civilian populace during their counter-offensive.\n\nAnother example, perhaps, can be found in the 1904-05 Russo-Japanese war. Technologically, the Japanese were more or less on par, due to a combination of local industry and import purchase, with their Russian foes and Western political allies, however, in most engagements, the Japanese were outnumbered and usually had inferior numbers of artillery pieces to the Russian foe. Yet they won; most put this towards a degree of overall skill and cunning versus relative Russian ineptness. Again, the war was relatively short, and the struggle was not to annihilation of a regime or state. \n\nIts true that the longer the war lasts, the more pronounced the ability to replenish losses becomes a dominant factor - be they human or material losses. Most examples one will find tend to be between nations of approaching technological parity, if not production parity, and the victorious if less industrialized party will generally win with a series of knockout blows (as the Japanese did indeed [try to do](_URL_0_) during WWII). Will to fight has a lot to do with it as well, if I could hazard a theory. ",
"another modern conflict you might add is the Russian invasion of Afghanistan. I think if both of the world's superpowers have lost modern wars to far less industrialized entities then what you suggest is hardly a \"rule\" of war.\n\nYou might also want to consider Portugal vs Angola, as well as the ALgerian revolution. ",
"The Spanish Civil War was an interesting case of the initially (industrially) inferior side eventually winning the war. Although Spain was rather undeveloped compared to the rest of western Europe, it did have some industry. \n\nWhen the war did break out, the Republic managed to maintain control over the most important industrial regions - Barcelona and Madrid, as well as the mines in the north - controlling 60% of the country with 70% of its tax base as well as most vital supplies that were in the country at the time. However only 30% of Spain's agriculture fell into Republican hands at the outbreak of the war. Luckily much of this agriculture was in citrus and other cash crops, which the Republic could sell overseas for its much needed foreign cash and supplies. Even in mid 1937 after losing a large chunk of its initial ground to Franco, the Republic was concluded to be self sufficient still. \n\nUnluckily for the Republic, though, they were plagued with disorganisation and internal revolution. With various parties fighting each other almost as much as Franco (especially the infamous May Days of 1937 in Barcelona), the Republic had to contend with little central control of the economy, as well as the large CNT collectivising industries and farms across the country (concentrated around Catalonia and Aragón) by its own accord and with variable success. With the rest of Republican government administration, the tax structure in the country crumbled with the breakdown of law and order in the initial outbreak, hindering their tax income efforts for at least the first year. \n\nOn the other hand, Franco managed to impose a fairly central and authoritarian economy, which had the benefit of foreign backing to keep it stable for the duration of the war, as well as the brutal methods the authorities used to keep the working population under control. \n\nAnother boost to the Francoists was their immense amount of foreign aid compared to the Republic. Almost as soon as the war started, Franco sought aid from Nazi Germany and Fascist Italy, which they both obliged with, particularly Italy which sent over 75,000 troops to aid the war effort over the 3 years of war. Franco received over $700 million (1940 USD) in aid completely on credit, compared to the Republican's $70 million from the Soviet Union. Furthermore, the Republicans had to sell their gold stocks to fund the rest of the aid from the USSR, which was the only nation willing to aid them due to the lack of willingness to intervene from France, America and Britain. \n\nFrancoist Spain managed to win the war despite their initial lack of potential in a war of attrition. Theoretically, the Republic should've won if one was to look at industry and manpower, but they didn't. It eventually came down to foreign support and internal stability, which Franco achieved much better. \n\nSources:\n\nSeidman, Michael. *The Victorious Counterrevolution*\n\nPreston, Paul. *The Spanish Civil War: Reaction, Revolution and Revenge*\n\nMartín-Acena, Pablo; Martínez-Ruiz, Elena; Pons, María. *War and Economics: Spanish Civil War Finances Revisited*"
]
}
|
[] |
[] |
[
[
"http://www.reddit.com/r/AskHistorians/comments/2gdct6/what_was_the_point_in_the_invasion_of_pear_harbor/cki7eus"
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[],
[]
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|
2blis4
|
what's the difference between a terrorist, a rebel and a separatist?
|
Russian/Ukrainian group shot down a plane killing nearly 300 people but they're called separatists. 2 men kill a soldier in broad daylight in the streets of London (they said they carried out the attack in response to the UK foreign policy) and they're called terrorists.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2blis4/eli5_whats_the_difference_between_a_terrorist_a/
|
{
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"text": [
"The terms aren't necessarily mutually exclusive.",
"Point of view.",
"A terrorist is someone who intentionally does acts of violence in order to instill fear or 'terror' in people to affect change or to carry out an ideology or idea.\n\nA rebel is someone who is a part of or builds a group of people trying to overthrow an existing government or president.\n\nA separatist is someone who usually wants to stay separate from a large group of people, or a government. ie.: The confederate states could be classified as separatist. \n\nSomeone can be a terrorist and not a rebel (Osama bin Laden). Someone can be a rebel and not a terrorist (Che Guevara, Founding Fathers of the US). Someone can be a Separatist and not a rebel (Jim Crow, Confederate Army).\n\nEdit: A separatist *could turn into* a rebel, and a rebel could turn into a separatist. It depends on the context or the political climate of whatever country these groups are working in."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
15i19c
|
Whatever happened to the Magi?
|
The Zoroastrian religion never died out, so what happened to its priests?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/15i19c/whatever_happened_to_the_magi/
|
{
"a_id": [
"c7mx3mh"
],
"score": [
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"text": [
"They are known by different names now. 'Magi' during the classical Greek period came to mean generally anyone skilled at astrology and so it was not specific to Zoroastrianism or a priesthood (think of the three wise men i.e 'magi' of the bible - the word there just means 'wise king' (wise because they knew to follow the star) there's also the linguistic impact of most of the community having moved out of Iran and in to India and further afield.... here's how the priests are now known: \n\n\nDastur - high priest\n \nMobed/Mobad - general word for 'priest' derived from middle-Persian used as an honorific for all ranks and specifically for a certain rank able to do ceremonies etc. \n\nHerbad - lowest ranking priest\n\nNB - Most Zoroastrians now live in South Asia and are know as Irani and Parsi \n\nThere are quite a few differences between the various populations in terms of calenders, festival dates, ritual and terminology The names I've given refer to Parsi priests but they could well differ with other communities. "
]
}
|
[] |
[] |
[
[]
] |
|
r4kyk
|
why does the internet hate skrillex so, so much?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/r4kyk/eli5_why_does_the_internet_hate_skrillex_so_so/
|
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"text": [
"I can't speak for the internet, but I can provide a logical explanation. I think we can both agree that not many people like dubstep. Skrillex is the face of neo-dubstep. When people despise something, they look at its most popular representation and hate him/her. \n\nBasically, skrillex represents dubstep, people hate dubstep, therefore they hate Skrillex. ",
"Because wub wub.\n\nSkrillex is the only dubstep artist that most people can name off the top of their head (at least strictly in the aggressive style). While many many many people like Skrillex, the internet has a tendency to hate stuff that many many many people like, particularly what has gained popularity with young girls and fraternity college boys. The internet's hate for Justin Bieber falls into the former category. Their hate for Skrillex and Nickelback falls into the latter.\n\nA lot of it does indeed fall into the \"everyone knows it so it sucks\" attitude as well.",
"I am fan of some actually good dubstep such as James Blake. Besides Skrillex looking like a fool, all of his songs sound the same.",
"People who don't like dubstep probably have only heard of Skrillex, so they focus on him.\n\nPeople who like dubstep because it is trendy also have probably only heard of Skrillex, so a disproportionate number of his fans are newbie poseurs. \n\nEveryone hates poseurs, so dubstep fans are quick to dismiss Skrillex so everyone will know they are \"real\" fans."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
||
4l8li3
|
Why don't waves through water travel at the speed of sound in water?
|
Okay so in materials I know that most acoustic (and optical as far as I know) waves will travel through the material at the speed of sound in that material (i.e. tapping on one end of a metal bar and seeing the response at the other end) but there are examples of things that display "wave-like" properties that do not follow this rule. These examples could be releasing a spring (especially with a low spring constant) and water traveling in waves. So I am just wondering what causes this difference and why these phenomena are observed?
My thinking, for the spring example at least, would be that the waves do travel through the spring or slinky at the speed of sound in the respective material but the overall response from the material happens over many waves with a slightly (atomically) larger response in one direction than the other with each wave?
|
askscience
|
https://www.reddit.com/r/askscience/comments/4l8li3/why_dont_waves_through_water_travel_at_the_speed/
|
{
"a_id": [
"d3lc6rj",
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"score": [
4,
9
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"text": [
"There's different kinds of waves. The waves that travel across the top of the water are much slower than the compression waves travelling through the water. This is because water is very difficult to compress, but it's not that hard to make the water a bit higher in some areas.",
"Waves like sound transport potential and kinetic energy through vibration and excitation. There is no mass transit.\n\nWater waves transport these energy forms as well but also exchange mass, causing impulse exchange and therefore viscosity effects to enter the picture."
]
}
|
[] |
[] |
[
[],
[]
] |
|
4i3jtf
|
How accurate is the show The Tudors?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/4i3jtf/how_accurate_is_the_show_the_tudors/
|
{
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"d2v4kwt"
],
"score": [
9
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"text": [
"I just finished watching it recently, so I looked into it. However, as I'm not expert on Tudor England, I'm just going to talk about a few specific things that I'm confident of.\n\nThe first, is the order of events and specifically their time. Sometimes the show changes the order of unrelated events slightly. \n\nThe show starts shortly before Henry's divorce of Catherine. It shows him as a young, vital, popular King. And certainly, this is how Henry was when he was young, and it's understandable of the show to want to show this, as most people just think of him as a fat middle-aged man. However, by the time of his marriage to Anne Boleyn, he was already 41. Henry was married to Catherine of Aragon for 24 years, but from their divorce to his marriage to Catherine Howard, it was only 11 years, in which he went through Anne Boleyn, Jane Seymour, Anne of Cleves and Catherine Parr.\n\nSo the show seems to be going through most of his life, from a young man to his death, but really, the first 3.5 seasons only cover about 12 or 13 years, with a few events from earlier put in.\n\nAnother thing they changed is some of the minor characters. Several characters are conflated, or swap roles, or don't fit their real personalities. \n\nFor example, Mary's sisters. In the show, Henry has one sister, Margaret, who marries the King of Portugal briefly, then secretly marries the upjumped commoner, the Duke of Suffolk. He later becomes Henry's longest serving councilor.\n\nHowever, notice that in the last series, Henry several times complains about his nephew, the King of Scotland?\nIn real life, Henry had two sisters. \n\nMargaret married the King of Scotland, and its her son James V that Henry is referring to. Her great-grandson of course, was to become James VI/I of Scotland and England (as Henry VII had considered in case his son's lineage died out, incidentally).\n\nThe other sister Mary, meanwhile, married the aged King of France (the father of the one in the show, who is shown to rule France for most of Henry's reign in the show, but actually didn't), not Portugal. Once he died of old age, she indeed secretly married the Duke of Suffolk as in the show, and Henry banished them temporarily from court.\n\nHowever, the real Charles Brandon, Duke of Suffolk, came from a wealthy noble family that had supported Henry VII and lost his father fighting Richard III (which is why he was raised with Henry VIII, and became one of his closest friends), and didn't do many of the things he's shown to do later in the show. He was indeed one of Henry's main advisors, and often led military campaigns, but some of the things he did in the show were actually things done by the Duke of Norfolk. That's the uncle of Anne Boleyn (and also Catherine Howard, not something shown in the show, where another guy turns up to be her uncle), who in fact survived the fall of his niece, and continued to be very powerful until late in Henry's reign, when he lost favour and was thrown in prison.\n\nSo, there are lots of small details that they changed. And of course, they don't show Henry as the obese man he was in old age, especially after his leg injury. \n\nOverall, however, I felt that while it's not up to the standards of historical accuracy that would be expected for an academic work, I don't think it's terrible. It does show reasonably, I think, the feel of the court, and of Henry's personality: how he started off as a fairly popular king, educated in the humanist way, but became more tyrannical and arbitrary over time. Also, the way the courtiers manipulate him. Finally, one thing I was pleased with is that I think, unusually for a popular history show, is that they show the central importance of religion, and how importantly people took it. For many characters in the show, religion is not just a political faction or something opportunistic, but also something they passionately, genuinely believe in. And yet, at the same time, they resist showing them as simply blind fanatics, as TV shows have a want to do with pre-modern religion. For example, Cromwell is corrupt, at times cruel, willing to compromise to keep the King's favour, but at the same time he is shown as genuinely believing in Protestantism (or, as they generally called it, Reform). Henry VIII resists going too Protestant because, as much as he wants a divorce, he genuinely believes in much of Catholic doctrine, and is suspicious of the reformers' goals. This does appear to be what Henry thought in real life.\n\nOverall... it's not perfect by any means, but it's much better than Reign."
]
}
|
[] |
[] |
[
[]
] |
||
223gwh
|
How can we hope to detect faint intelligent signals from exoplanets when we aren't even able to detect the light from those planets?
|
Wouldn't any signals sent from some other intelligent life 20 light years away (f.ex.), be extremely weak? Even a signal from that distance at 1GW (which is very strong) would, if I did the math correctly, be of the order of 10^-27 watt/m^2 :O Can we detect this?
|
askscience
|
http://www.reddit.com/r/askscience/comments/223gwh/how_can_we_hope_to_detect_faint_intelligent/
|
{
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"cgj0hqt",
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7
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"text": [
"Well... the problem with seeing an exoplanet is that the star is so bright you can't get a long enough exposure to see the planet's light. (like trying to see a speck of dust near a spotlight) There are some neat strategies to work around this, like a giant shadow-casting shield that you'd space in front of your telescope to block the star's light, but allow the planet to be visible.\n\nBut yes too.. it's seemingly unlikely that *random* broadcasts would be visible outside of their neighborhood (maybe a light year or two), with signal being lost to noise. But maybe if you were to focus a beam, you'd have less energy loss over distance, and extend your range. But now you have to point at a target in addition to having a high power source.\n\nSo if we detect external signals it will almost certainly be a deliberate attempt to send an interstellar message in our direction.",
"Aside from what others have said, it's a question of spectrum.\n\nStarts are really loud in certain portions of the EM spectrum. But in other parts (radio waves), they're really quiet. That is, if you could look at the sun in that part of the spectrum, it would be pretty dark. In those frequency bands, it's not hard for even 20th century technology to \"out-shine\" the sun.\n\nYes, those signals dissapate to super-small watts/m^2, as you say, but if you tune your humongous radio dish (or your phased dish array) to the bands where stars are dark, there's no problem other than collecting enough signal to detect it over background noise."
]
}
|
[] |
[] |
[
[],
[]
] |
|
ls1p2
|
When you ingest salt NaCl what does the body do with the chlorine after the sodium is absorbed?
|
askscience
|
http://www.reddit.com/r/askscience/comments/ls1p2/when_you_ingest_salt_nacl_what_does_the_body_do/
|
{
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"[NIH Glossary - Chloride](_URL_0_)",
"\"In the upper part of the small intestine, chloride ion absorption is rapid nd occurs mainly by diffusion (i.e., absorption of sodium ions through the epithelium creates electronegativity in the chyme and electropositivity in the paracellular spaces between the epithelial cells). Then chloride ions move along this electricl gradient to \"follow\" the sodium ions.\" source Guyton and Hall Medical Physiology 12th ed. Just wanted to provide a source for your comment. ",
"Cl- is also absorbed by the gastric mucosa.\nIt can be secreted back into the stomach if needed to increase HCl concentration there.\nIf not needed Cl- can stay inside the cell to be used. There is a certain Cl concentration inside the cells. But this concentration is very little compared to its extracellular concentration as Cl is one of the two major negative charges in the extracellular fluids (the other is bicarbonate).\n\nSo if there is more Cl in the cell than needed it will move out of the cell. It will stay in the blood or be filtered in the kidneys.\n\nIn the kidneys Cl will be reabsorbed or excreted.",
"Much of it is lost in urine. \n\nLike other posters have mentioned, it also plays a big role in balancing out all of the positive charges floating around in the plasma/urine (sodium and potassium, mostly). It also tags along with some of the cations through co-transporters to facilitate movement across membranes and stuff.\n\nAll in all, it's pretty much the wallflower of electrolytes. Sodium, potassium, and bicarb are way more interesting.",
"Chloride ions are also important in the CFTR (cystic fibrosis transmembrane receptor) protein. It's an ion channel specifically for Chloride that allows free movement of the ion which facilitates the movement of water molecules into the mucous to keep it fluid like. When the CFTR protein doesn't work you get the disease cystic fibrosis.",
"Chloride concentration is an important aspect of the resting membrane potential of neurons (_URL_0_.) Furthermore, GABAA and GABAC subtypes of GABA receptors are ionotropic receptors that, in response to GABA, open and allow permeability of a cell to chloride. Traditionally speaking, since the concentration of chloride is so much higher in the extracellular space, this causes an influx of chloride into the postsynaptic neuron, thus causing it to hyperpolarize. Therefore people tend to think about GABA as an \"inhibitory neurotransmitter\" and chloride as an inhibitory ion. However recent research has suggested that cells in the brain actually have a highly variable resting membrane potential, and that depending a number of factors, chloride can in fact efflux from cells when GABA channels are opened, making the action excitatory. ",
"[NIH Glossary - Chloride](_URL_0_)",
"\"In the upper part of the small intestine, chloride ion absorption is rapid nd occurs mainly by diffusion (i.e., absorption of sodium ions through the epithelium creates electronegativity in the chyme and electropositivity in the paracellular spaces between the epithelial cells). Then chloride ions move along this electricl gradient to \"follow\" the sodium ions.\" source Guyton and Hall Medical Physiology 12th ed. Just wanted to provide a source for your comment. ",
"Cl- is also absorbed by the gastric mucosa.\nIt can be secreted back into the stomach if needed to increase HCl concentration there.\nIf not needed Cl- can stay inside the cell to be used. There is a certain Cl concentration inside the cells. But this concentration is very little compared to its extracellular concentration as Cl is one of the two major negative charges in the extracellular fluids (the other is bicarbonate).\n\nSo if there is more Cl in the cell than needed it will move out of the cell. It will stay in the blood or be filtered in the kidneys.\n\nIn the kidneys Cl will be reabsorbed or excreted.",
"Much of it is lost in urine. \n\nLike other posters have mentioned, it also plays a big role in balancing out all of the positive charges floating around in the plasma/urine (sodium and potassium, mostly). It also tags along with some of the cations through co-transporters to facilitate movement across membranes and stuff.\n\nAll in all, it's pretty much the wallflower of electrolytes. Sodium, potassium, and bicarb are way more interesting.",
"Chloride ions are also important in the CFTR (cystic fibrosis transmembrane receptor) protein. It's an ion channel specifically for Chloride that allows free movement of the ion which facilitates the movement of water molecules into the mucous to keep it fluid like. When the CFTR protein doesn't work you get the disease cystic fibrosis.",
"Chloride concentration is an important aspect of the resting membrane potential of neurons (_URL_0_.) Furthermore, GABAA and GABAC subtypes of GABA receptors are ionotropic receptors that, in response to GABA, open and allow permeability of a cell to chloride. Traditionally speaking, since the concentration of chloride is so much higher in the extracellular space, this causes an influx of chloride into the postsynaptic neuron, thus causing it to hyperpolarize. Therefore people tend to think about GABA as an \"inhibitory neurotransmitter\" and chloride as an inhibitory ion. However recent research has suggested that cells in the brain actually have a highly variable resting membrane potential, and that depending a number of factors, chloride can in fact efflux from cells when GABA channels are opened, making the action excitatory. "
]
}
|
[] |
[] |
[
[
"http://ghr.nlm.nih.gov/glossary=chlorideion"
],
[],
[],
[],
[],
[
"http://en.wikipedia.org/wiki/Resting_potential"
],
[
"http://ghr.nlm.nih.gov/glossary=chlorideion"
],
[],
[],
[],
[],
[
"http://en.wikipedia.org/wiki/Resting_potential"
]
] |
||
36q63b
|
Can any given 2D shape be expressed as a single (probably incredibly complex) equation, or do many shapes require a piecewise graph?
|
If I were to draw any random line or shape on a piece of paper, it could be expressed as a long and complicated piecewise graph, but is there a single equation for each and every random shape? If no, then what if the shape had to be continuous? If still no, then what about only functions, or only 1-to-1 functions rather than any 2D shape?
|
askscience
|
http://www.reddit.com/r/askscience/comments/36q63b/can_any_given_2d_shape_be_expressed_as_a_single/
|
{
"a_id": [
"crgtttk"
],
"score": [
3
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"text": [
"Yes. I used to waste so much time in high school typing long formulas into my TI-83 to get it to graph shapes I drew out ahead of time on graph paper. With enough time on your hands, you can use its parametric grapher to graph out your signature.\n\nI used the [Nyquist-Shannon sampling formula](_URL_0_). It smoothly interpolates between sampled points using sine curves. (Meaning, the sine function is used in the sampling; the points them selves are not joined with sections of sine curves the way you might be thinking of them.) If you draw a kooky shape, and record the coordinates of lots of points on the shape very precisely, you can use N-S sampling to reconstruct the shape using a very long sum of sines. The number of terms is equal to the number of sampled points."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem#Shannon.27s_original_proof"
]
] |
|
28g1r4
|
How did the sections of US states become known as "counties" even though they have never been ruled by counts?
|
If counties were already in place before the Revolution, why didn't the states then choose to relabel them to something less indicative of the nobility and crown? If counties were formed after the Revolution, why emulate British nobility at all?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/28g1r4/how_did_the_sections_of_us_states_become_known_as/
|
{
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95,
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"text": [
"Point of order: The British counties have never been ruled by counts (or viscounts): it stems from the Normans, who simply took over the Saxon shires (that's why it's all \"Hampshire\", \"Cheshire\", \"Renfrewshire\" etc.), but brought their Norman French with them (counts actually being a thing on the continent).\n\nHistorically, British counties started out as either kingdoms in their own right ~~after~~ from before Alfred the Great, or just happened to be the administrative division used for taxes (and sheriffs and things).\n\n^(edit: spelling; edit 2 19:23 UTC: slip of tongue)",
"Follow-up question: in Louisiana, our counties are called \"parishes.\" And for all my years of living here I've never learned why?",
"Although it's a state issue, does anyone know why Virginia is a \"commonwealth\"? It is *also* a state, but common referred to as \"the Commonwealth\" and what have you. "
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
abqck8
|
Modern day concrete still doesn’t compare to the concrete made by the Romans. How was the recipe lost?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/abqck8/modern_day_concrete_still_doesnt_compare_to_the/
|
{
"a_id": [
"ed2p2dm"
],
"score": [
4
],
"text": [
"I don't mean to discourage further discussion, but this topic emerges quite often. You might want to read the response by /u/TectonicWafer in [this discussion](_URL_0_). For some additional insight, you may also read the short discussion about 'losing knowledge' [here](_URL_1_)."
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/23893y/how_did_we_lose_the_ancient_roman_invention_of/",
"https://www.reddit.com/r/AskHistorians/comments/4k29dg/we_as_a_civilization_lost_the_ability_to_create/"
]
] |
||
4m2qqb
|
the difference between a particulate, gas, and vapor
|
I was looking at [respirators](_URL_0_) because I was curious as to what my filter could do and I came across the aforementioned three terms and I really can't tell the difference between a particulate and a vapor, and vapor and gas.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4m2qqb/eli5the_difference_between_a_particulate_gas_and/
|
{
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2,
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"text": [
"Particulate is just very small pieces of solid material. Vapor is a substance diffused in the air which would normally be solid or liquid; think of water vapor. A gas is... a gas.",
"Particulates are debris in the air from solid objects\n\nVapors come from solid or liquid objects that would be solid or liquid at room temperature \n\nAnd gasses don't coincide with solids or liquids ",
"* Particulate - small solid particles dispersed into the are\n* Vapor - individual molecules mixed in with the air, but not at high enough of a temperature to be a gas...sometimes incorrectly used as a synonym for gas\n* Gas - molecules travelling at high enough speed they cannot for the temporary and permanent bonds that characters liquids and solids"
]
}
|
[] |
[
"http://multimedia.3m.com/mws/media/447121O/filter-change-out-brochure.pdf"
] |
[
[],
[],
[]
] |
|
261vpa
|
Do male and female human genitalia exhibit a similar degree of variation in length and width?
|
askscience
|
http://www.reddit.com/r/askscience/comments/261vpa/do_male_and_female_human_genitalia_exhibit_a/
|
{
"a_id": [
"chn19qn"
],
"score": [
3
],
"text": [
"There definitely is substantial variation in the size of the female reproductive tract, but I am not aware of any studies that actually try to compare the variability to that for penises.\n\nIt would be a challenging study because the vagina both opens up and lengthens quite substantially during arousal and at different times in a woman's cycle, and it would be hard to keep everything consistent when taking measurements. It would be like trying to do a study on average penis size, but all you get is a bunch of penis measurements but it's random and unknown whether the measurement was taken while erect of flaccid. You would have to measure the same woman several times in several different states."
]
}
|
[] |
[] |
[
[]
] |
||
4hq8ek
|
is the united states currently at war?
|
I feel like in the past it has been pretty easy determine when we are at war. I considered myself to be pretty up to date when it comes to news but today there are so many small conflicts in the middle east I dont actually know if we are even currently at war. Also having a military spread out all over the globe can make it even more confusing. So:
1. Are we at war?
2. What are our goals if we are at war?
3. Are we making any progress with these goals?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4hq8ek/eli5is_the_united_states_currently_at_war/
|
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"text": [
"No. To be at war, Congress has to basically say \"we declare war against _____\". They have not said that, therefore, we are not at war. ",
"1. Technically, no, but we are dropping bombs on multiple continents. \n\n2. They're not very specific goals, which is part of the reason it's just seems like endless combat.\n\n3. The war on terrorism has been going on for 15 years, and all we've done is make more terrorists. So...no.",
"Anymore this is a good question. Reminds me of of this exchange in 2002 on The West Wing:\n\nAdmiral Percy Fitzwallace: Can you tell when it's peacetime and wartime anymore? \n\nLeo McGarry: No. \n\nAdmiral Percy Fitzwallace: I don't know who the world's leading expert on warfare is, but any list of the top has got to include me, and I can't tell when it's peacetime and wartime anymore.",
"We are at war in virtually any meaningful sense, we have just refused to call it such because that word has real legal and political ramifications.",
"1. Technically no but by any reasonable metric of what \"being at war\" mean, yes.\n\n2. If you consider the limited cases of intervention in the ME our goal is the deterrence of non-state Islamist militias such as ISIS (when you are recognized by 0 other countries, you are not a state in a way that is meaningful as far as a description of US foreign policy toward non-state actors), Al Shabaab, and the Taliban and the strengthening of the recognized governments in the areas those groups operate in or, in the case of Syria, the containment of ISIS with a tacit recognition that the Assad regime will likely stay mostly in place.\n\n3. It depends. The Taliban is alive and well in Afghanistan and the peace process with the Afghani government collapsed as it was revealed that the Taliban's leader had been dead for 2 years (most of the group's low ranking members didn't know), which fragmented the group and scuttled the peace process. ISIS is losing territory and fighters in both Syria and Iraq. However, Syria is not much closer to any stable government, even one controlled by Assad. Al Shabaab is a lot weaker than it has been in years past ."
]
}
|
[] |
[] |
[
[],
[],
[],
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[]
] |
|
35qwno
|
Do 2 atoms of the same element (I.e hydrogen) always weigh the same? Why or why not?
|
askscience
|
http://www.reddit.com/r/askscience/comments/35qwno/do_2_atoms_of_the_same_element_ie_hydrogen_always/
|
{
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"No, two atoms of the same element will not always have the same mass. Two atoms of the same element can have a different number of neutrons in their nuclei. Since neutrons have a significant mass compared to electrons, this can lead to an important difference in mass between the various isotopes of an element. This fact is very important to isotope enrichment, such as is needed to develop nuclear bombs.\n\nAdditionally, atoms can be in different ionization states, meaning that they are missing electrons or have extra electrons. Since electrons carry mass, an atom that is missing an electron will have less mass then an otherwise identical atom in the neutral state.\n\nEven if two atoms are the same element, the same isotope, and in same ionization state (they have the same numbers of electrons, protons, and neutrons), they can still have slightly different masses. Due to E = mc^2 , when energy is pumped into an otherwise closed system, the system as a whole gains mass. Therefore, two atoms of the same element, isotope, and ionization state can be in different excitation states and therefore have slightly different masses. All of the pieces of an atom (electrons, neutrons, and protons) can be excited to higher energy levels within the atom."
]
}
|
[] |
[] |
[
[]
] |
||
25i2mi
|
Did the Nazis view blonde-haired and blue-eyed Slavs and Jews as any better than the others?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/25i2mi/did_the_nazis_view_blondehaired_and_blueeyed/
|
{
"a_id": [
"chhm72s"
],
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"text": [
"The blond-hairs / blue eyes thing is actually a gross simplification of the racial policies of Nazi Germany. They were mainly obsessed with blood purity and Japanese were seen as vastly superior to the slavs despite not having blond hairs. \n\nA good example of this obsession for blood purity was Reinard Heydrich, a high ranking Nazi who, despite being the archetypical pure aryan in appearance (blond, ruthless and a fanatical nazi), has been the target of a smear campaign where rivals launched rumors according to which he had a Jewish ancestor, meaning he was not pure aryan.\n\nIt was a very grave accusation for a Nazi official and the Reich paid a \"racial expert\" to investigate closely Heydrich's genealogy to make sure the rumors were unfounded. His report showed that Heydrich had no \"Jewish taint\" in his blood. If the report got positive Heydrich would probably have been in trouble and could have been expelled from Nazi party.\n\nAll that to show you that it was not really about hairs or eye color but about purity and ancestry. Slavic people had a unpure blood for the Nazis and so did the jews, meaning that if you had the taint you were good for the concentration camp, whatever your eye or hair colors were.\n\nConcerning the accusations of being unpure toward Heydrich, you can read more about these in *\"Hitler's hangman: The life of Heydrich\"* by Robert Gewarth."
]
}
|
[] |
[] |
[
[]
] |
||
1hw7ky
|
what are the benefits of methadone/a methadone clinic?
|
I'm having trouble understanding the use and effects of methadone. Is it a drug like heroin? Does a methadone clinic just give you methadone if you're a recovering addict? and is it better than just trying to stop using drugs at all?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1hw7ky/eli5_what_are_the_benefits_of_methadonea/
|
{
"a_id": [
"cayiudy"
],
"score": [
2
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"text": [
"It's an opiate like heroin so users wont withdraw and it's little less extreme. You can think of it like shorts with cigarettes, good for tapering off if you're trying to quit."
]
}
|
[] |
[] |
[
[]
] |
|
epiwej
|
How did RBMK reactors come to be and how were they different from other models used in the western world?
|
How did RBMK reactors come about? What was their evolution from the early versions to the latest models? How did they differ from the models used by the western countries?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/epiwej/how_did_rbmk_reactors_come_to_be_and_how_were/
|
{
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"text": [
"Briefly, the RMBK was a very unusual reactor design, optimized for the demands of the Soviet bureaucracy and production needs. The basic requirements that the RMBK was trying to satisfy were:\n\n* the design had to be a relatively cheap way of producing gobs of electrical energy\n\n* the reactor was designed to be capable of being designed and manufactured locally, as opposed to in a centralized facility (this is related to the cheapness and the labor model)\n\n* the military (who essentially ran the reactor development program) wanted it to be capable of also producing plutonium for military purposes (no RMBKs actually did this, but they wanted the option)\n\nThe result was a reactor that looks very different from most Western reactors and looks even different from the other main Soviet design, the VVER, which is basically the Soviet equivalent of the Pressurized Water Reactor (PWR). The PWR/VVER both require very specially produced reactor vessels, and both use expensive containment domes, and both are essentially difficult to use for the production of military plutonium (you can't circulate fuel through them very quickly). The RMBK by comparison does not have a special reactor vessel, lacked a containment dome, and could circulate fuel very quickly. Importantly they could use the existing Soviet industrial workforce very efficiently, without the need to construct new facilities or train workers for radically new skills — this was a high priority in the late 1970s USSR, when the design was approved.\n\nThe RBMK had significant safety problems which are obvious in retrospect, though it is of note that with careful operation, the accident rate can still be very low (there have been RMBKs operating continuously since Chernobyl without incident). Similarly one can run VVER/PWRs in ways that produce accidents (Three Mile Island was PWR accident), and the other major design in operation, the Boiling Water Reactor, has its own flaws as well (Fukushima was a BWR accident). Obviously the lack of a containment dome is dangerous no matter what — this was also an artifact of the Soviet bureaucracy and engineering culture, in which to admit the possibility of engineering fault was seen as attacking the Soviet state. \n\nI think it is worth noting that _every_ reactor design has the hallmarks of its original priorities and goals written upon it. The RMBK is not unique in this respect, though the specific priorities and goals are very attuned to the place and period it was created, and, regrettably, said priorities and goals were less focused on safety than they ought to have been, with grave consequences. \n\nAs I always emphasize, you can design a reactor for whatever priorities you want (safety, economy, plutonium production, whatever), but some of these priorities can interfere with one another (e.g., if you optimize for economy you can cut into safety, and vice versa). So it is important that you know what your priorities are, and what priorities your production and regulatory systems are set up to honor. In the case of the RBMK, it is clear that safety and transparency were far too under-valued, both in the reactor design, but also in its operation.\n\nIf you would like a lot more detail into the development of the RBMK and VVER, Sonja D. Schmid's _Producing Power: The Pre-Chernobyl History of the Soviet Nuclear Industry_ (MIT Press, 2015) is the best technical history of Soviet reactor development prior to Chernobyl, and goes into great detail into how the institutional divisions (between, say, the military and civilian aspects of nuclear power in the USSR) and priorities shaped these technologies."
]
}
|
[] |
[] |
[
[]
] |
|
1e9r1q
|
How long does it take for a particle to loop around LHC? How much does it change for the particle due to time dilation?
|
Since time passes slower(/faster depending on perspective) for muons traveling close to c and space 'warps' so that they see the atmosphere as ≈50 meters deep. How long does a trip around LHC seem to a particle and how long does the particle 'think' it is?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1e9r1q/how_long_does_it_take_for_a_particle_to_loop/
|
{
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"_URL_0_\n\n > When running at full design power of 7 TeV per beam, once or twice a day, as the protons are accelerated from 450 GeV to 7 TeV, the field of the superconducting dipole magnets will be increased from 0.54 to 8.3 teslas (T). The protons will each have an energy of 7 TeV, giving a total collision energy of 14 TeV. At this energy the protons have a Lorentz factor of about 7,500 and move at about 0.999999991 c, or about 3 metres per second slower than the speed of light (c). It will take less than 90 microseconds (μs) for a proton to travel once around the main ring – a speed of about 11,000 revolutions per second. \n\nSo, if the protons going around the LHC each had watches, their watches would appear to elapse by (9 x 10^-5 s) / (7500) = .012 microseconds, from a stationary observer's point of view. Of course, in the protons' reference frame, time would appear to pass normally, but the the watch on the stationary observer would appear to move very quickly.\n\nEdit: Yes, I should have divided to get the indicated time on the proton as observed from a stationary position. From that point of view, it would appear that the protons' watches were moving very slowly (and I confused myself into thinking that time moving slowly corresponded to a larger delta on the proton watch - not the case, as is clearly indicated in comments below)."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Large_Hadron_Collider"
]
] |
|
vhzgj
|
if sea level has been rising then how come it is not evident from the beach yet?
|
ELIF: I have lived in a city with a seashore my whole life. I have seen the tides come in and go out and I am yet to see any effects of a rise of sea level. As I understand the (man made) climate change has been happening for more than a 100 years. Shouldn't we have seen at least some effect on the sea level every where? What makes scientists think the level will rise quickly in the coming decades?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/vhzgj/if_sea_level_has_been_rising_then_how_come_it_is/
|
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"text": [
"From 1993 to 2009 the sea level has risen 3.3mm/yr - that's not very much and would be almost impossible to notice. [Source](_URL_0_)",
"The sea has risen by about 15cm due to the 0.8^o C rise in global temperatures so far; this is not enough to notice on a typical beach without careful measurement. \n\nSome places, such as Tuvalu and Bangladesh, have experienced more drastic and obvious effects due to the rise.\n\nScientists are concerned that the rise will increase much further in future partly due to positive feedback loops causing greater warming. These are due to things like a reduced albedo, released methane from ice sheets, and a positive feedback between temperature and CO2.\n\nThe rise in sea level is largely due to the melting of ice on land. The ice masses are mahoosive and take a long time to melt. Even without further warming the ice will continue to melt for several centuries so the sea will rise further in any case.",
"The problem with anthropogenic climate change is that its a positive feedback loop.\n\nThe CO2 we make raises the temperature around the world by 1 degree C. This causes some ice to melt at the poles, which raises water levels and exposes more ice to the water. With less ice to reflect the sun's rays, more light is absorbed, raising the temperature another degree.\n\nIn this time, we've put out enough CO2 to raise the temperature another degree. This 2 degree change melts more ice, raises the water levels more, and raises the temperature by another 2 degrees.\n\nWe do some hard-handed emissions control and reduce out emissions so that we only raise it by .5 degrees. This 2.5 degree change melts ice, raises the sea level, and elevates global temperatures by 2.5 degrees.\n\nAnd so on, and so forth. The temperature change that our CO2 causes generates another temperature change, which causes another and another. This means that the CO2 we made in the Industrial Revolution may still be affecting the current climate, and we've only been piling on more and more CO2 in the intervening years before we even began any emissions control programs. Of course, this example is highly exaggerated and hyperbolic, but that's the idea; that the cycle feeds itself, and our output, instead of simply adding a degree to the global temperature, is adding a degree to the **rate of change** of global temperature.",
"_URL_0_\n\nThe Maldives are slowly being swallowed by the ocean due to rising sea levels. It is happening, and this nation is in serious danger."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Current_sea_level_rise"
],
[],
[],
[
"http://www.treehugger.com/climate-change/sea-levels-rise-maldives-president-may-move-his-entire-island-nation-australia.html"
]
] |
|
1el04p
|
Why do we feel comfortable in some positions and not others?
|
I had a friend ask this today and no one knew the answer. I know it's not as sophisticated a question as others, but intriguing nonetheless.
|
askscience
|
http://www.reddit.com/r/askscience/comments/1el04p/why_do_we_feel_comfortable_in_some_positions_and/
|
{
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"text": [
"It has a certain degree to do with blood flow. This also explains why we roll around in bed at night- in some positions, blood may be restricted to some areas due to pressure on the blood vessels, so we roll to another position to redistribute the bloodflow.\n\nHow comfortable you are in a position whilst concious is likely to be more to do with how much pressure are on certain body parts or how strenuous that position is."
]
}
|
[] |
[] |
[
[]
] |
|
2869tg
|
food stamp fraud
|
So I just finished watching the episode of orange is the new black where SPOILER!!! they explore Gloria's food stamp fraud situation. What exactly was she doing with the food stamps to get cash from them? I understand she purchased them from other people, but how did she turn the cards into cash?? I tried looking it up, but I can't find an explanation for what the receiver of the cards can do to make money off them.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2869tg/eli5_food_stamp_fraud/
|
{
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"Vendors (grocery stores, etc) receive reimbursement from the government for accepting food stamps as payment for (approved) food items. Things that cannot be purchased with them include non-food items, hot pre-prepared foods, as well as cigarettes and alcohol. \n\n\n\nWhat she was doing was allowing people to pay for non-eligible items with food stamps. This was beneficial for her because she would charge more and pocket the difference. So for a $10 case of beer she might charge $20 in food stamps and then keep the extra $10 for herself.\n\n\n\nShe would then submit to the gov for reimbursements and make up fake receipts for eligible things that people \"bought\""
]
}
|
[] |
[] |
[
[]
] |
|
9o64w8
|
why does your neck get tense when you’re stressed and how does a massage fix it?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9o64w8/eli5_why_does_your_neck_get_tense_when_youre/
|
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"When you are stressed, you experience fight-or-flight, even if the stressor is emotional/psychological in nature. When this response occurs, it causes you to produce more adrenaline. Adrenaline causes muscle tension (muscle tension being a sign of stress). If you massage a muscle, you can cause that muscle to relax. So stress increases adrenaline, causing muscle tension, massage relaxes muscles.",
"Typically when you're stressed most people clench their jaw or tense their muscles without realizing it. After so long that muscle will stay tense. MT helps to release those muscle from all that tension by applying pressure in certain areas of the muscle to have it \"let go\". Stretching the muscle(s) helps as well because tension can cause muscles to shorten. ",
"Animals curl up into a ball when they are threatened. This is part of the “fight or flight” response. Our brains evolved in a world full of predators and dangers. The problems of our modern world like stress over money or friendships trigger the same “fight or flight” response. That part of our brain isn’t smart enough to know the difference. That’s why stress tenses us up into knots, and why stretching in the opposite direction can feel really good.\n\nAs to why massage “works”, I’m not totally sure — I think it’s something people are still debating over.",
"Forgive my formatting as I'm on mobile and forgive the oversimplification.\nThere are a few reasons why on both sides (why im tense vs why I stop being tense.) Muscles are affected by certain nerotransmitters when you're stressed. Also, hydrogen and collegen can bind together muscle fibers and create knots. Also part duex, a lot of people dont tend to realize they clench their jaws or move their head forward when they are stressed. Massage (of which there are several modalities) can in essence break apart muscle tissue, leading to fibroblasts (the clean up guys) and lymphatic fluid to clear up those transmitters, while the massage itself affects the parasympathetic nervous system and releases other neruotransmitters that help relax muscles. For knots, we use something called friction, stripping or deep transverse friction that literally help pull apart the muscle tissues and those hydrogen,collagen bonds or taught bands of tissue. So in essence, we kind of best your muscle up in a nice way and good neurotransmitters fix the rest.",
"When people are tense, they tend to shrug their shoulders up (no idea why). We're not talking shrugging a lot, but it's enough to activate the trapezius muscle and the muscles of the neck. Overtime, the muscles get sore and contracted from having been activated for so long. When they've been contracted for so long, it's also hard for the muscle fibers to relax and release to their normal length. This is what you experience as an achy/sore neck.\n\n The reason a massage fixes it is due to the massage forcing the muscle fibers to extend again. When the muscle fibers can lengthen to their normal range, bam, no tightness.",
"I’ve seen explantations on why it gets tense so I’ll just tell you what might help. I work at a salon that offers massage and one of the massage therapist told me just having someone put pressure on your neck/shoulders with there elbows helps a lot. It has made a huge difference. Hope this helps!",
"If you've ever seen a cat or dog get frightened, you'll notice they puff up and try to look bigger. This is a response to danger and our body experiences stress in the same way. We tuck our shoulders up and keep our head low. Doing this for a long time can cause the muscles tension. An easy way to massage this is to slowly rotate your neck from the left, to down, to right and back again over and over. You can also shrug and relax your shoulders. Lastly, hold your finders on one side of your neck close to your shoulders, pretty tight but not too tight, and then cock your head to the opposite side slowly, then move your fingers a bit higher and repeat. The key to any stretching is if it hurts, don't do it. If you're still experiencing pain, you should consider seeing your doctor. Many insurance plans cover massage for rehabilitation of injury, most massage chains won't/can't bill your insurance, so try to go to a sports medicine specialists, they employee masseuses that can bill your insurance. Source: Me, 36 free massages a year baby!",
"As the other redditors have thoughtfully and thoroughly explained the reasons why your neck gets tense and the effect of the massage i wont get into it but instead give you an alternative. A massage is(usually) a temporary relief for the muscles as it just takes a new series of stressfull events and boom your muscles are tense again. \n\nNow the tension in the muscles is nothing but stored information: stress that has tensed up the muscles in reaction to a stressfull situation. However by learning how to breathe with the belly in a relaxed and calm manner you can project that sense of calm feeling towards any tension point in the body, making it relaxed(provided you are in a correct upright posture).\n\nAlso breathing and emotions are linked, for example by experiencing or thinking about something anxious your breath shortens and becomes more shallow(try it). So by controlling the breath you not only can learn to relax your muscles but also keep your stress away from physically manifesting in your body. \n\nPeace :)\n",
"Your neck muscles don't have much to do, and they are quite complicated. Because we rarely workout the neck muscles they don't get practice lining up correctly. When the rest of your body is under stress the neck tries to help, and the muscles contract in unexpected ways. ",
"Now you know the why. Now seek help from massage, yoga, tai chi, acupuncture, and acupressure. All these are great at helping relieve the tension.",
"One of the only perks to the house I overpaid for is a hot tub. Am I imagining it helps the occasional sore back & neck, and if so, how?",
"Hiya! Massage Therapist here. \n\nMuscles can do lots of things! You can use them to move parts of your body around, like your arms and legs. You can also use them to hold yourself really still, like a statue! This is called tensing up. When you use your muscles to tense up, it’s really hard for anyone to push you around. Try it! Have a friend try to push you over while your body is relaxed. Then have them try to push you while your muscles are tense, and feel the difference. Tensing up can protect you!\n\nNow, when a person is overly stressed, they may feel the need to be in a constant state of protection, and stay tense all the time. This is called ‘hypertension’ (double edit: that isn’t the correct term, forgive me! It’s really called hypertonicity.). The shoulders and neck are the most common place for stuck tension, but it can be held in different places all over the body.\n\nWhen a muscle is constantly contracted, it can cause some problems. Tense muscles restrict blood circulation, which can prevent the muscle from getting the nutrients it needs to be healthy. Also, a muscle that doesn’t relax and can limit the amount of movement your body can do.\n\nPhew! That was a lot of information! Let’s shake it out before we continue.\n\nOkay, so now we get to the good stuff: how does massage actually help? The simple answer is that it takes the muscles out of tension, and into a supple, relaxed state. BUT HOW? \n\nFirst, a massage can only be effective if the person can relax. They need to be in a space where they feel safe, where they can lower their tension defenses. This is why spas and massage studios pay extra attention to atmosphere and ambiance. Soft music, low lights, and privacy are standard in most massage spaces.\n\nThen you get to the actual massage. There are a ton of techniques that massage therapists use to loosen muscles! By kneading, stroking, pressing, shaking and/or tapping muscles, we help them out of tension and into relaxation. Without the tension, you can move the muscle more easily, the circulation to the area improves, and posture improves. \n\nAlso, there can be great emotional relief alongside the physical relief, when you can shift away from feeling defensive and locked down.\n\nI hope this helps, I know it’s long-winded. Feel free to ask me any questions you have about the benefits of massage! I love the field, and am so happy to help people feel better in their bodies all day!",
"While some people have explained the relationship between your flight-or-fight system and muscle tension, I would actually suggest that massages often by untrained hands or even at the hands of professionals have lower success than exercising the muscles. I can explain further if you prefer but I will say this, I suffer from frequent tension in my traps and neck because I sit down for long hours in the day and spend a decent amount of time studying in bed. The thing about most massage therapies is that often they are very acute or short term solutions and won't solve the roots of the problem. Personally I do a particular resistance band exercise for relief and I make sure to have frequent \"walking breaks\". \n\n\nSource: 4th Year Kinesiology Student ",
"How many people just started rubbing their sore neck and shoulders? I did.",
"Essentially, muscles have different types of fibers and neuro-sensory organs that responds to different types of stimuli and elicit a response. Some of these receptors are mechanoreceptors and they respond to pressure differences. Within the muscles, our two main sensory organs that elicit a response are muscle spindles and golgi tendon. And in simple terms, golgi tendon organs are those that respond to an overload of tension and fires up the opposite muscle so that the muscle that is currently contracting, relaxes before there is damage. This is the protective mechanism you have when you have this heavy load you can't maintain and you automatically just drop it. The other sensory organ is the muscle spindle. This is the one where there is a stretch , or lengthening of a muscle because of a load, so this fires up so that that same muscle contracts so there's no lengthening. This is the one you are mainly using all the time, like holding your phone. Now knots has to deal a lot with this mechanism. More often than not it's more of a neuronal component and with that, you have to also consider nerve insertions and piercing points of fascia. Fascia is the covering of your muscles that serves as lubrication and provides glide, for the most part. Now...knots are thought to be an over stimulation of these muscle spindles...where your muscle sustain contraction for a long time, hence slouching or being sat in a particular way or even diseases processes can illicit the nervous system to activate. this creates a reflex that then elicits your muscles to contract. And there you have your knots. When you are stressed you are activating your sympathetic system, the fight-or-flight respond. If sustained, this can lead to a hyperactivation of this reflex. Now, you've probably heard of stress points where most often than not you'll find a knot. This if I'm not mistaken, has to deal with nerve penetrating the fascia. So, there are multiple things that can happen. Be it that the nerve is hyperactivated and is causing congestion around the fascial penetration spot. Or that because of an awkward muscle contraction you have, the fascia is creating pressure on the nerve causing it to fire and sustain that knot... you'll have a knot. Lol. Now massages can help with by different mechanisms. Be it that you are creating direct inhibition, hence removing the congestion around the nerve and then leading to relief. Or direct inhibition causing a break from the reflex loop hence no sustained contraction, or the mechanoreceptors responding to this different type of pressure that then relaxes the muscles...You are essentially trying to reset the system. And this leads either way to the activation of inflammation, to \"heal\" the area. Hence why you can feel sore or bruised a day or two after massages. Now...going back to the neck...It's all anatomy. So we need to know muscles, bones and nerves and their location. From a chiropractor or Osteopathic medical approach, you have to consider articulation dysfunctions, at the level of joints. That could be pinching or shortening a muscle. Think of the same thing but with nerves. In terms of muscles, your trapezius, splenius capitus, levator scapulae, scalenes, sternocleidomastoids and your suboccipital muscles are your major culprits for neck pain under stress. Also, especially if you have a propensity of headaches and migraines, your suboccipital muscles will be tight. These are the muscles at the back of the base of your skull. You more likely than not if you have migraines, you'll have a tenderpoint/knot at the opthalmic nerve (facial nerve V1 branch) that will radiate to the back/posterior base of the skull wherever your suboccipital/occipital nerves exit through. And these can lead to these pains. By treating the reflex...you can aid these things and these symptoms might diminish.",
"Ok, sidebar here, from a nerdy ((and pedantic) massage therapist:\n\nThere are lots of responses here, all giving very reasonable and more or less science-y sounding answers expressed with absolute confidence. They're all missing one important thing.\n\nHere's the somewhat awkward truth: we don't really know. In fact, the answer to most questions about massage is \"We don't know for sure.\" There are a lot of things that we know definitely work, and we have some theories as to why, but we aren't really sure. \n\nThere are a couple of really good reasons for this. \n\nFirst, massage is really hard to study in a scientifically rigorous way. You can't even do a proper blind study - every subject will know whether or not they got a massage! \n\nThe second reason is that to really understand how massage works, you'd have to be able to see what's going on in a living body on a sub-microscopic level in real-time, and we don't have any way to do that. Through decades of studying chemical structures of proteins and other components in muscle tissues and nerve fibers, scientists have developed a really good sense of how these things work, and *some* of the ways things can go wrong. But there are still lots of failure modes that aren't well understood yet.\n\nSo, if we don't know exactly why your neck gets tense when you're stressed, or why massage fixes it, what *do* we know? Well, let's start with a basic understanding of the feedback loop that regulates the tension in any given muscle (or really, any cluster of muscle fibers within a muscle):\n\n1. Sensory receptors in and around every muscle in the body, every second of every day, send information up to the brain. This includes pressure sensors in the muscle that detect contraction, stretch sensors in the tendons, chemical receptors throughout the muscle tissue that detect inflammation, and more.\n2. The brain receives all this info, and compares it to past experience to estimate the current position, motion, and state of every body part, including the current tension of each muscle. (When you close your eyes and wave your arms around and you can feel where they are, this is what makes that possible.)\n3. The brain determines the difference between the position and motion of each body part vs where it wants those body parts to be, as well as the current contraction state of each muscle, and contracts or relaxes all muscles accordingly. (This is why you're capable of walking, or even standing, without falling over.)\n4. Return to step #1.\n\nSo, if a muscle is more tense (that is, trying to contract more) than it should be - or, if just a few fibers in a muscle are tense, as in the case of a \"knot\" - the problem could be at any step of that process. Perhaps the tissues are sending incorrect or contradictory information to the brain, or the brain is misinterpreting the information, or the brain is sending the wrong signals to the muscle, or the signal from the brain isn't reaching the muscle properly. And of course, there are several possible causes for each of these.\n\nMassage could help any of those situations. It can increase lymphatic flow, flushing out metabolic byproducts that might interfere with nerve signals or with the muscle's ability to respond. It could also \"recalibrate\" the brain's sensorimotor system, by sending a wide range of unusual signals - for example, I can stretch the tendon at one end of the muscle without simultaneously stretching the other end - something that rarely happens naturally, forcing the brain to \"recalibrate\" its idea of what a given sensory input means.\n\nWithout being able to trace individual nerve signals, let alone look at the chemical changes inside a muscle cell from one millisecond to the next, it's surprisingly hard to tell for sure exactly which of these things is happening, and why, and how. Which is why the most honest answer to why massage works is still almost always \"I don't know.\"\n\n & #x200B;\n\nSo, with that huge disclaimer, let's finally come back to your original question: my own pet theory, based on what I've read and my personal experience, is something like this: \n\nUnder normal circumstances, it's very rare that you'll keep the same muscle active for an extended period. You're always making small movements and adjustments, giving any particular group of muscle fibers a chance to relax every now and then. When you're under stress, however, as others have pointed out, your brain switches to \"fight or flight\" mode, releasing cortisol, adrenaline, and other hormones into your body. This can cause you to tense up all your muscles in preparation for sudden action. It can also help you to hold very still, perhaps as you focus intently one one thing. And then, of course, the mental distraction of the stress may cause you not to consciously notice that you've held one muscle tight long enough that it's getting uncomfortable.\n\nAt some point, when you perform this unusual action of keeping a muscle tight for a very long time, something goes wrong in the feedback loop above. Perhaps the tight muscles inhibit lymphatic flow, causing a build up of metabolic byproducts, causing inflammation. Or perhaps fatigue of the overworked stretch sensors causes the brain to misinterpret their signals, or start to ignore them completely. For whatever reason, that muscle (or part of a muscle) keeps trying to contract more than is appropriate. Then you get a massage, and (one way or another) everything is cleared out and recalibrated, and you feel better.\n\nWhy does this happen in the neck, specifically? Well, it can happen anywhere, and different people \"carry their tension\" in different places. The thing about the neck is, those muscles are pretty busy. If you're not lying down, you're probably using those muscles to support your head. And especially if you spend your days at a desk, looking at a screen or at paperwork or anything involving focused attention, not looking around much, while feeling stressed and anxious... it's just asking for trouble!",
"I have constant neck and back pain. Sometimes it’s not too bad but sometimes it still hurts even when I’m just lying in bed. I’m a side and stomach sleeper which I’ve heard is bad, but I absolutely cannot sleep on my back. Is there anything I can do to help it? Supportive pillows? Should I be finding a massage therapist? Any ideas? ",
"I always thought it was because your head fills up with thoughts when your anxious and gets heavier and adds stress to your neck. ",
"I completely recovered after getting familiar with Sarno's TMS hypothesis. Hope it will do for you what it did for me.",
"The explanation hinges on whether you are prepared to accept the existence and function of the subconscious or unconscious portion of the human mind. If you can accept it, there is a very adequate explanation (largely not accepted by mainstream medicine) that has fallen out of favor, though has never been disproven.\n\nObviously, if the pain is caused directly by injury or disease that can be explained with clinical diagnostic, then the pain is caused by that injury or disease. However, where there is no obvious explanation for the pain, the pain may be caused by stress or essentially, your own brain. What is pain caused by the brain? Psychosomatic illness or symptoms. What is the psychosomatic illness caused by? Suppressed or repressed anger -- the most powerful emotion. Why would the brain cause you pain? To offer a distraction from your unsolvable or inescapable problems or let downs in life that you may consider inescapable, to, in essence, allow you to function.\n\nThe brain frequently picks a 'favorite' site to locate physical psychosomatic pain. I carried my psychosomatic pain in my shoulders/neck for many years, and after a back injury, my brain then 'preferred' to locate my psychosomatic pain in my back instead. Long after my back injury had healed, I still had un-explainable back pain (like 3 bloody years later!).\n\n & #x200B;\n\nPlease let me explain (and sorry for the wall of text, oof).\n\n & #x200B;\n\nSarno^(1,2) believes that the purpose of psychosomatic symptoms or pain are to offer a distraction, to relieve the person suffering of emotional pain, by substituting physical symptoms instead. The bigger the stressor, the more unsolvable, the more intractable, the more emotionally painful it is, the greater the risk is of developing psychosomatic symptoms, and the greater the resulting psychosomatic pain.\n\nPsychosomatic illness or symptoms causing pain are largely unconscious, as in not under any direct voluntary executive conscious control, reactions to strong emotions, particularly anger. This doesn't mean the pain is made up, it means, we aren't even aware its made up, and cannot certainly just pretend it away. The pain is very real, the muscle tension is real, the symptoms are real. The cause, however, is not organic: it is our own brain.\n\nHow does the brain cause pain? As Sarno^(1,2) points out, there are studies that show that enervated muscle tissue suffering from psychosomatic pain actively has lower oxygen content. Sarno believes that the brain is capable of utilizing the autonomic nervous system to deprive target tissues of blood flow, and hence oxygen. Nerves that are deprived of oxygen are capable of generating pain.\n\nMassaging the affected areas may increase blood flow, and hence, temporarily alleviate the tension symptoms.\n\nWhat do psychosomatic symptoms include? They can include muscle pain, particularly lower back pain that doesn't have any obvious cause, depression, anxiety, sleep problems, IBS, fibromyalgia, among others.\n\nFreud is largely credited with documentation and early work on this, however, his insistence that psychosomatic illness was as a result of repressed sexual feelings missed the mark.\n\nLater work (by Sarno^(1,2), Hanscom^(3), Schechter^(4), Schubiner^(5), and Kellerman^(6)) has shown that suppressed or repressed anger or rage is the primary emotion that drives psychosomatic illness. Why repress rage? Because those of us who act on it and lash out end up ostracized, in fights we may not win, hurting people, losing our jobs, or ending up in jail. Thats why. As social animals, we evolved to repress rage.\n\nHow does suppressed or repressed anger or rage work? According to Kellerman^(6) ,Sarno^(1), and Luskin^(7), subconscious anger is generated when we experience let downs, stress or our 'wishes' or expectations in life don't get met. Note this is normal: we either (1) don't get what we want, (2) don't get what we want the way we want it, (3) in the amount we want it in, (4) or when we want it.\n\nThe anger may also be the result of grevious insult or injury, caused by accidents, abuse, crime (assault, rape, or murder of family member or loved one), see Luskin^(7).\n\nCertain personalities of people, as Sarno^(1,2) pointed out, seem to be at higher risk for developing symptoms of psychosomatic illness. People who suffer from 'goodism', or want to do the right thing and internalize anger very readily may suffer moreso from psychosomatic symptoms.\n\nAccording to Hanscom^(3) and Sarno^(2), symptom relief provided by massage therapy, accupuncture, chiropractic manipulation, physiotherapy may simply be providing temporary relief of the pain caused by psychosomatic illness, but in the end all of these are possibly a placebo, and do not treat the cause (again, if the cause is not an obvious injury or clinically diagnosable disease).\n\nOne way to rid yourself of the anger causing the psychosomatic symptoms is to forgive those who have transgressed against you or caused you emotional suffering. As Luskin^(7) points out, many people who suffer from anger and hurt, decades later, caused by grevious injury or injustice, gain better emotional peace of mind by forgiving.\n\nThe more I read about it, the more I am fascinated by anger as an emotion.\n\n & #x200B;\n\nReferences:\n\n1. Sarno, John. The Divided Mind: The Epidemic of Mind-Body Disorders. 2009. Harper-Collins. [_URL_4_](_URL_4_). Also, _URL_7_\n2. Sarno, John. The Mindbody Prescription: Healing the Body, Healing the Pain. 1999. [_URL_1_](_URL_1_)\n3. Hanscom, David. Back in Control: A Surgeon's Roadmap out of chronic pain. 2016. Vertus Press. Also [_URL_0_](http://_URL_0_).\n4. Schechter, David. Think Away Your Pain: Your Brain is the Solution to Your Pain. 2014. MindBody Medicine Publications. Also [_URL_3_](_URL_3_)\n5. Schubiner, Howard. Unlearn Your Pain. 2010. Mind Body Publishing. [_URL_6_](_URL_6_). Also, [_URL_2_](_URL_2_).\n6. Kellerman, Henry. The 4 Steps to Peace of Mind: The Simple Effective Way to Cure Our Emotional Symptoms. 2007. Rowman & Littlefield. [_URL_8_](_URL_8_).\n7. Luskin, Fred. Forgive for Good: A Proven Prescription for Health and Happiness. [_URL_5_](_URL_5_)\n\n & #x200B;",
"wait what neck is this?",
"dealing with this now. Been so stressed out about my thesis defence, while writing for hours on end i think i have been clenching and lifting my shoulders (towards my ears). Been seeing a PT for it...but it just wont go away. Hopefully soon it will.",
"Stress is often acompanied by unconscious muscle tensing. \nWhen muscles are tensed in a sustained manner, they can block the lymphatic system from collecting and purging the body of toxins. Massages works by loosening those pathways, allowing the lymphatic system to do its job",
"And how does a Sauna/Hot tub help with this?\n\nOne of my last massages included 30 minutes in a sauna before the massage, and that did something to my muscles which really improved the effect on my muscles during the massage. It was like a whole other level of therapy."
]
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|
[] |
[] |
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[],
[],
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"www.backincontrol.com",
"https://www.amazon.com/gp/product/0446675156/",
"https://www.unlearnyourpain.com/",
"https://www.mindbodymedicine.com",
"https://www.harpercollins.com/9780061860584/the-divided-mind/",
"https://www.amazon.com/Forgive-Good-Proven-Prescription-Happiness/dp/006251721X",
"https://www.amazon.com/Unlearn-Your-Pain-Howard-Schubiner/dp/0984336702",
"thankyoudrsarno.org",
"https://www.amazon.com/gp/product/0742558789",
"http://www.backincontrol.com"
],
[],
[],
[],
[]
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||
4knpgb
|
Knowledge of coats of arms in medieval Europe
|
So, this crossed my mind while watching the recent Game of Thrones episodes. (Note: this post does **not** contain spoilers.)
How familiar were knights supposed to be with coats of arms and names of noble families? Specifically, I'm asking in the context of wars and battles. Was a knight supposed to know all the coats of arms and banners of all the other knights in his army, so that he didn't strike down an ally by accident? Or maybe there were some noted cases of 'friendly sword stabs' and 'friendly axe chops' (sorry) during battles because someone didn't know that 'Two Longaxes Beneath a Black Crown' fought on the same side?
Also, would a noble family's child be expected to learn by rote memorization all the names and coats of arms of families they might come across on a regular basis?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/4knpgb/knowledge_of_coats_of_arms_in_medieval_europe/
|
{
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"text": [
"Yes, a noble was supposed to know the coat of arms of at least the important lords, at least in his own army (because it's rather easy to deduce who's an enemy when you know who's your friend).\n\nThe most notable example for this (or rather for it's absence, from which a presumed knowledge for nobles can be inferred) is the Battle of Worringen in 1288, the battle with the largest amount of knights in the middle ages. \n\nThe leader of the one side was Siegfried von Westerburg, Archbishop Elector of Cologne, who sported more armored riders than soldiers on foot, making infantry for him rather negligible mostly used to guard the baggage train. On his opponents side fought the people of Cologne, who wanted to weaken the position of the Archbishop to better their own position within the city politics (the Archbishop had a very strained relationship to the citizens of Cologne, with one of his predecessors having been evicted from the city by force at one point).\n\nMost of these people of Cologne were fighting on foot and were not part of the patricians but regular citizens. Now, this militia of citizens had no formal training and very little \"noble\" education - and subsequently, when they entered the fray, they attacked everyone (or rather: all armored riders) indiscriminately, which is attributed to them not knowing friend from foe because they could not recognize the colors of the nobles.\n\nAnother factor for why knowing the colors of ones enemy was important was that battles in the Middle Ages were not really fought to the death. The goal was to take as many of the enemy knights as prisoners to ransom them to pay for the massive costs of waging a war. Knowing who is who is rather essential if you want to know who needs to be spared at almost all costs because a high ransom is to be expected. \n\nSo to summarize: Yes, a noble was supposed to know the colors of his friends at least and of his enemies to a large extent when he went to war. \n\nSadly I can't give you a source for it in English, but on the off chance that you can read German, this information is taken from:\n\n*Lehnart, Ulrich: \"Die Schlacht von Worringen 1288. Kriegführung im Mittelalter. Der Limburger Erbfolgekrieg unter besonderer Berücksichtigung der Schlacht von Worringen\", Frankfurt 1993*"
]
}
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[
[]
] |
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7nj53r
|
Do any animals live at the extreme poles and how do they survive?
|
I know of the animals that live near the poles such as penguins and polar bears. But this usually refers to the coastal parts of the polar surface (Coasts of Antarctica and the coast of the northern ice sheet). Do any animals live inland and actually close (say within 100 km) of the actual poles? How do they feed themselves without access to plants or sea?
|
askscience
|
https://www.reddit.com/r/askscience/comments/7nj53r/do_any_animals_live_at_the_extreme_poles_and_how/
|
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"text": [
" > A lone polar bear, tracks of an Arctic fox, unidentified sea creatures, and several birds have been observed at the North Pole over the years.\n\n[Source](_URL_0_) - you still have the ocean as food source.\n\nAt the South Pole: Technically humans live there, and a few animals live on them. But outside the research station I didn't find any mention of animals living there."
]
}
|
[] |
[] |
[
[
"https://www.worldatlas.com/articles/what-animals-live-in-the-north-pole.html"
]
] |
|
6a77wt
|
how do tolls work? do you really get in trouble for running one?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6a77wt/eli5_how_do_tolls_work_do_you_really_get_in/
|
{
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"dhc7rz0"
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"text": [
"You mean on a road? A machine will take a photo of your license plate if you go through without paying. Some offer an option to pay the toll afterward, by Web or by mail. (Some don't have that option.) You may get a fine/ticket in the mail if you don't pay."
]
}
|
[] |
[] |
[
[]
] |
||
3qbb9v
|
What are the best sources to understand Gaius Marius's reforms in Rome?
|
[deleted]
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3qbb9v/what_are_the_best_sources_to_understand_gaius/
|
{
"a_id": [
"cwfaig8"
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"score": [
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"text": [
"Sorry it took me a while, hope this is helpful. The bibliography from my old Marian Reforms paper follows. Especially useful were Gabba, Kildahl, Smith. If you want my full paper (with page numbers for references) let me know, I'll find a place to put up the pdf or you can PM me with an email address. Cheers.\n\n\nAdcock, F. E. The Roman Art of War Under the Republic. New York: Barnes and Noble Books, 1995.\n\nCicero. De Republica. In The Political Works of Marcus Tullius Cicero: Comprising his Treatise on the Commonwealth; and his Treatise on the Laws Vol I. Translated by Francis Barham. London: Edmund Spettigue, 1841-42.\n\nDobson, M. The Army of the Roman Republic: The Second Century BC, Polybius and the Camps at Numantia, Spain. Oxford: Oxbow Books, 2008.\n\nGabba, E. Republican Rome, the Army, and the Allies. Berkeley: University of California Press, 1976.\n\nGoldsworthy, A. The Roman Army at War 100 BC-AD 200. Oxford: Clarendon Press, 1996.\n\nKildahl, P. Caius Marius. New York: Twayne Publishers, 1968.\n\nLivy. Ab Urbe Conditi Libri. Translated by F. G. Moore. Cambridge: Harvard University Press, 1949.\n\nPlutarch. Gaius Marius. In Fall of the Roman Republic. Translated by Rex Warner. London: Penguin Books, 2005.\n\nPlutarch. Tiberius Gracchus. In Makers of Rome. Translated by Ian Scott-Kilvert. London: Penguin Books, 1965.\n\nSallust. The Jugurthine War. Translated by John Selby Watson. New York and London: Harper & Brothers, 1899.\n\nScullard, H. From the Gracchi to Nero: a History of Rome 133 BC to AD 68. London: Routledge, 1982.\n\nSeyffert, O. Dictionary of Classical Antiquities. Edited by H. Nettleship and J. E. Sandys, _URL_0_.\n\nSmith, R. Service in the Post-Marian Army. Manchester: Manchester University Press, 1958."
]
}
|
[] |
[] |
[
[
"http://www.ancientlibrary.com/seyffert/index.html"
]
] |
|
1kqquy
|
how did humans in asia evolve to have narrower eyes, why did africans skin stay black while arabic and european peoples became lighter?
|
No offense meant, just phrasing the question as best I can as to how some humans evolved with certain traits and how the process occurred.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1kqquy/eli5_how_did_humans_in_asia_evolve_to_have/
|
{
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"text": [
"If you live in the tropics, dark skin is a helpful adaptation, because it protects your skin from sunlight (fewer sun burns and cancers).\n\nIf you live in the northern latitudes where there is significantly less sun certain times of the year, light skin is a helpful adaptation, because it allows more sunlight to penetrate the dermis, thereby creating more vitamin D.\n\nThe primary characteristic of east Asian eyes is called the *epicanthic fold*, and we believe it may have evolved to protect the eye from harsh winds, but the jury is still out on that one.",
"It was recently discovered that a collection of physical traits typical in Asian populations (thicker hair shafts, more sweat glands, teeth shape, smaller breasts) are all the result of a single gene mutation that occurred 35,000 years ago in what is now China. There are a few explanations as to why that may have spread through generations to become so widespread, but scientists aren't sure which is correct. It could be a combination of them. This article goes into detail:\n\n > extra sweat glands could have been the feature favored by natural selection, with all the other effects being dragged along in its train...the EDAR variant arose about 35,000 years ago in central China and that the region was then quite warm and humid. Extra sweat glands would have been advantageous to the hunter-gatherers who lived at that time.\n\n > Thick hair and small breasts are visible sexual signals which, if preferred by men, could quickly become more common as the carriers had more children. \n\n > each of the effects of the EDAR variant may have been favored by natural selection at a different time. A series of selections on different traits thus made the variant version so common among East Asians.\n\n_URL_1_\n\nOf course these gene isn't responsible for the eye shape (epicanthic fold) common in Asian populations, but it's the same principle. \n\nMelanin is the pigment in human skin that makes it dark. It protects from the harmful effects of the sun's UV radiation, keeping the UV from damaging skin and the DNA in our skin cells.\n\nAs early humans migrated out of Africa, they were all dark from having evolved near the equator and needing the protection of melanin from the fierce sun. At some point, a mutation arose in a population that had migrated out of Africa that caused lighter color skin.\n\n > Some scientists suggest that lighter skin offered a strong survival advantage for people who migrated out of Africa by boosting their levels of bone-strengthening vitamin D; others have posited that its novelty and showiness simply made it more attractive to those seeking mates. \n\nEDIT: Vitamin D is made in your skin as a reaction to sunlight, so the Vitamin D theory of light skin goes that in the weaker sunlight of northern climates, having a light skin mutation gave you an evolutionary advantage because more of the sun's energy would penetrate the skin for form Vitamin D.\n\n_URL_0_\n\n**TLDR** We don't know for sure but here's the \"how\" and some theories \"why.\"",
"I'll link the TED talk video for skin colors... give me one second..\n\nedit: [Nina Jablonski: Skin color is an illusion](_URL_0_)",
"I don't want to sound racist but black people often have larger lips/ a bigger mouth, why is this?",
"I am not sure what the proof was for this, so I am gonna run with it as if it were a hypothetical. It has been theorized that the northeastern breezes that keep western europe unseasonably warm are the root cause for pale caucasian skin.\nSee, there are people ALL over the planet at the similar latitudes as western Europe, getting the same amount of winter sun as western Europe, but only in one place do we have white people. This stems from the warm atlantic breezes that have allowed western Europeans to get a longer growing season for gathering of vegetables, hunting of red meat animals and eventually the growing of grain. Other lattitudes don't have this, and subsisted on a fish diet for much of the winter. A diet heavy on the fish provides vitamin D, so the people in similar latitudes never had to develop lighter skin, hair and eyes. \nNo clue if it's true, but it sure sounds good, huh?\n",
"One possible theory goes like this: way back in the day, there were multiple species in the genus *homo*, particularly the Neanderthals in Europe and the Middle East, the Denisovans in Asia, and of course the Homo Sapiens (us) in Africa. Sometime in the last 200,000 years (sorry, I can't remember eras off the top of my head) lots of the Homo Sapiens migrated from Africa to Europe, the Middle East, and Asia. As they did this, the Denisovans and Neanderthals became extinct. However, recent studies have yielded an interesting finding: European/Middle Eastern genes are about 4% Neanderthal DNA, while Native Australian/Asian genes contain around 6% DNA. This means that somewhere along the way, some Homo Sapiens decided, AND were able to procreate with members of other species. This could possibly have a relationship to the way people from certain regions look. However, this is just one theory.\nTL;DR Asians, Middle Easterns, and White People aren't 100% Homo Sapien.",
"Skin color appears to have been an adaptation to the wavelength of ultraviolet light. We need this ultraviolet light to stimulate the production of vitamin D. But if we get too much of this ultraviolet light, you'll just get skin cancer. So dark melanin blocks out most of the ultraviolet light, but lets enough through to still make vitamin D.\n\nBut beyond a certain latitude this wavelength of ultraviolet light is diminished. This is just because of the angle of refraction of sunlight through the atmosphere during the day. So dark pigmentation just diminished the ability to produce vitamin D. Removing the the pigmentation allows what little of this wavelength of ultraviolet light to be absorbed for the purpose of making vitamin D.\n\nThe narrower eyes for Asians -- I have only a guess: You don't get that sort of pervasive change over such an area without significant sexual selection. That is to say, you don't find pockets of east Asians in certain regions that have non-east Asiatic features. At the same time, west of the Himalayas there are basically no east-Asiatic features. Furthermore, nobody can think of any real adaptive advantage to the east-Asian features. So my feeling is that the best explanation is the same explanation for why there are usually an \"Asian\" categories on porn sites: There is a slightly stronger sexual desire for Asian features in humans. And over time in isolation, for about 40,000 years, the Asians cultivated fluke occurrences of eastern-Asiatic features until it was the most pervasive physical appearance.\n"
]
}
|
[] |
[] |
[
[],
[
"http://www.washingtonpost.com/wp-dyn/content/article/2005/12/15/AR2005121501728.html",
"http://www.nytimes.com/2013/02/15/science/studying-recent-human-evolution-at-the-genetic-level.html"
],
[
"http://www.ted.com/talks/nina_jablonski_breaks_the_illusion_of_skin_color.html"
],
[],
[],
[],
[]
] |
|
8y6s37
|
Wehrmacht Clean Hands in the West?
|
Obviously the Wehrmacht committed all kinds of atrocities in the East: helping to implement the Holocaust and the genocide of the Slavs (the Hunger PLan, General Plan Ost). However, is it true that they more or less abided the Geneva Conventions and the norms of war in the West? Perhaps this is the source of the clean hands myth? Or is this another lie? I heard something to this effect in a documentary about Rommel and the Afrikakorps.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/8y6s37/wehrmacht_clean_hands_in_the_west/
|
{
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"e28me84"
],
"score": [
2
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"text": [
"As for Rommel specifically: more can be written on this, but you might want to read [\"Rommel's legacy\"](_URL_0_) by /u/commiespaceinvader.\n\nEDIT: As for the source of the Wehrmacht Clean Hands myth, I suggest the reply to [\"Did the Rommel Myth and Clean Wehrmacht myth (and others) pushed after World War II come from Government level or Academia?\"](_URL_1_) also by commiespaceinvader, with a bibliography at the end. Replies by /u/kieslowskifan and /u/]Georgy_K_Zhukov list books for further reading.\n\nEDIT 2: I *am* sorry for not looking further down in previous postings before writing this. A few examples of Wehrmacht war crimes in the west (scattered in more about the east) is in [\"Just how much of the Wehrmacht was dirty?\"](_URL_2_) , again by commiespaceinvader.\n\nThis is not to discourage discussion. Further questions, data, and debate are welcome.\n"
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/619lia/rommels_legacy/dfd5n4f/",
"https://www.reddit.com/r/AskHistorians/comments/5799li/did_the_rommel_myth_and_clean_wehrmacht_myth_and/d8suoyk/",
"https://www.reddit.com/r/AskHistorians/comments/3xc03h/just_how_much_of_the_wehrmacht_was_dirty/cy3cxs0/"
]
] |
|
n0lrw
|
Could we just inject dopamine and other molecules that cause feelings of well-being into our bodies and stay happy for the rest of our lives?
|
If we could, every other human activity would be pointless, as we only do such things to be happy( i.e. get dopamine rushing through our bodies), right?
|
askscience
|
http://www.reddit.com/r/askscience/comments/n0lrw/could_we_just_inject_dopamine_and_other_molecules/
|
{
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"text": [
"There is no safe or effective happiness treatment. Short term happy pills (e.g. cocaine, which causes elevation in levels of dopamine right in the areas that cause you to feel happy) don't work for long. \n \n > If we could, every other human activity would be pointless, as we only do such things to be happy( i.e. get dopamine rushing through our bodies), right? \n \nI think that's partly right. Rats that learn to electrically stimulate their own mesolimbic dopamine pathway get such a great high that given the choice between food or sex and another hit of stimulation, they can willingly starve themselves to death for another hit. Some heroin users have said that heroin fills a void that makes them feel fulfilled and all the yearning that they ever had for love, accomplishment, etc. is all addressed wonderfully and nothing else is needed anymore (during the high). Soon thereafter, of course, more heroin is needed. ",
"You cannot give Dopamine as a drug for the use you're implying. Dopamine administered peripherally (tablet, injection, etc.) does not cross the blood-brain barrier and won't act centrally. In fact, Dopamine has some pretty bad side-effects (nausea, namely) when administered peripherally. This was found when scientists tried treating Parkinson's disease with Dopamine.\n\nYou can use Dopamine's precursor, L-Dopa, which does cross the blood-brain barrier where it is converted to Dopamine by dopa decarboxylase. This is often paired with Carbidopa which prevents peripheral conversion of L-Dopa to Dopamine.",
"There is no safe or effective happiness treatment. Short term happy pills (e.g. cocaine, which causes elevation in levels of dopamine right in the areas that cause you to feel happy) don't work for long. \n \n > If we could, every other human activity would be pointless, as we only do such things to be happy( i.e. get dopamine rushing through our bodies), right? \n \nI think that's partly right. Rats that learn to electrically stimulate their own mesolimbic dopamine pathway get such a great high that given the choice between food or sex and another hit of stimulation, they can willingly starve themselves to death for another hit. Some heroin users have said that heroin fills a void that makes them feel fulfilled and all the yearning that they ever had for love, accomplishment, etc. is all addressed wonderfully and nothing else is needed anymore (during the high). Soon thereafter, of course, more heroin is needed. ",
"You cannot give Dopamine as a drug for the use you're implying. Dopamine administered peripherally (tablet, injection, etc.) does not cross the blood-brain barrier and won't act centrally. In fact, Dopamine has some pretty bad side-effects (nausea, namely) when administered peripherally. This was found when scientists tried treating Parkinson's disease with Dopamine.\n\nYou can use Dopamine's precursor, L-Dopa, which does cross the blood-brain barrier where it is converted to Dopamine by dopa decarboxylase. This is often paired with Carbidopa which prevents peripheral conversion of L-Dopa to Dopamine."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
|
920ix6
|
*How* do left/right handed molecules form and how are they different?
|
I understand that they're mirror reflections of each other, but what makes them left or right handed? My first thought when the concept occured to me in chemistry was that it's just an relatively upside down molecule. My reasoning was that the properties shouldn't change simply because you see it at a new angle. Now though, I'm hearing of these exact things as though they were more than just a different perspective.
What makes the molecules different in a way that isn't just a change of perspective? I couldn't find an explanation of *why* or *how* this is on Google as it was only returning the *what*.
|
askscience
|
https://www.reddit.com/r/askscience/comments/920ix6/how_do_leftright_handed_molecules_form_and_how/
|
{
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"e32uhhg",
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2
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"text": [
"Your left hand is structurally distinct from your right hand. In other words, there's no orientation, rotation or any translation that will turn your right hand into your left hand. What this means is there's absolutely no way to put your left hand in a right handed glove and vice-versa (have a go).\n\nThis chirality, as its termed, works in the exact same way for molecules. For example, 'left handed' molecules can't fit into 'right handed' enzymes. An enzyme would be right handed because it's made up of smaller right handed molecules.\n\nI just to make sure that it's understood that not all objects can be left or right handed. Just because it has a mirror image it doesn't mean the mirror image is the other hand. For example, imagine you put a mirror next to a coffee cup and then removed the mirror but kept the reflection there as a real object. You could translate one of the cups into the other and they would perfectly match - they are the exact object. And that's the key. Left and right handed objects/ molecules are structurally distinct objects/ molecules.",
"Even though they have the same chemical composition they function differently S isomers (left isomers) and R isomers (right isomers) are shaped functionally different. Much in the way you can’t put a square peg through a round hole you can’t expect an s isomer to work where an r isomer is supposed to. They also have different chemical properties. I can’t remember which right now but one of the isomers of a common NSAID will get rid of a headache the other will kill you. Because they’re shaped differently and the body breaks them down differently "
]
}
|
[] |
[] |
[
[],
[]
] |
|
55466s
|
what causes things to sound differently such as a breaking glass sound vs typing on a keyboard?
|
How does the composition of these materials affect the sound they can produce, if any, once disturbed in some fashion.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/55466s/eli5_what_causes_things_to_sound_differently_such/
|
{
"a_id": [
"d87f02l"
],
"score": [
3
],
"text": [
"Sound is air vibrating. The air vibrates because it's being bumped into by a surface that's vibrating. Those surfaces have different characteristic amplitude and frequencies due to their materials, construction and size. So a large, flappy piece of paper is going to make very different vibrations than a big brick, when given similar energy inputs. Then the air in their vicinity is vibrated from the surface vibrating and different sounds are produced. \n\nThink about it: How fast can you shake a marble back and forth? Can you shake a bowling ball at the same number of oscillations per second? (Well, yes, but the amount of energy required goes up in proportion to the mass). Or hit a bowl of jello with a hammer and hit a bowl of mashed potatoes with the same hammer. Which one jiggles more? At a microscopic level, that is what is happening to the air molecules that make the sound. "
]
}
|
[] |
[] |
[
[]
] |
|
9x4gw6
|
How was King Alfred able to beat the Vikings?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/9x4gw6/how_was_king_alfred_able_to_beat_the_vikings/
|
{
"a_id": [
"e9pqkfc"
],
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"text": [
"Honestly whole books and theses have been written on this.\n\nI've written a little about it [here](_URL_0_).\n\nFor reading I would recommend Hill *et al*, *The Defence of Wessex*; Baker and Brookes, *Beyond the Burghal Hidage*; Reynolds *et al*, *Landscapes of Defence*; Stenton, *Anglo-Saxon England*; Lavelle, *Alfred's Wars* and *The Danes in Wessex* to start with. Our primary sources are *The Anglo-Saxon Chronicle* and Asser's *Vita Ælfredi*.\n\nTo put things very briefly: Viking warfare is based on rapid manouevre and avoiding fair fights as much as possible. As Asser recounts for the year 871, Wessex spends so much manpower chasing down small forced and defending against raids that when it comes to pitched battle, its forces are often outnumbered and exhausted.\n\nAlfred's strategy comes from a mass overhaul, reform and bureaucratisation of the Anglo-Saxon defensive infrastructure. Potentially influenced by the fortified bridges over the River Seine to defend Paris from the Vikings that he would have witnessed on his childhood visits, as well as earlier English fortification networks from Offa's Mercia, the new *burghal* system essentially establishes a system of fortified garrison sites at roughly a day's march from each other at major road junctions, river crossings, bridges, landings etc. These severely limit the Vikings ability to outmanoeuvre the English, and instead allow an organised military reaction force to rapidly respond to Viking threats."
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/8qiw9b/z/e0jta84"
]
] |
||
2fipq4
|
What is human skin actually made up of? Is it technically a human organ?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2fipq4/what_is_human_skin_actually_made_up_of_is_it/
|
{
"a_id": [
"ck9of4i"
],
"score": [
4
],
"text": [
"An organ is a collection of tissues that perform a specific function. The skin is an organ that provides protection from the outside world to our viscerals. \n\n\n\nThere are three layers to the skin: the outermost **epidermis**, the **dermis**, and the underlying **hypodermis**. The epidermis is almost entirely keratinocytes arranged in five distinct layers; dead cells that slough off are constantly replaced by new cells pushing up from the lower layers of the epidermis. The dermis and hypodermis are layers of connective tissue and fat that physically and physiologically support the epidermis and protect the body. As such, these two deeper layers facilitate the routing of blood vessels and nerves to the skin, and provide the scaffolding for hair follicles, sebaceous glands, and sweat glands. The involvement of myriad cell types to make our skin function is what characterizes it as an organ."
]
}
|
[] |
[] |
[
[]
] |
||
2mhthp
|
is this paper about roundup being dangerous legit?
|
_URL_0_
EDIT: Sorry for the crappy title.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2mhthp/eli5_is_this_paper_about_roundup_being_dangerous/
|
{
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"text": [
" > Consequences are most of the diseases and conditions associated with a Western diet, which include gastrointestinal disorders, obesity, diabetes, heart disease, depression, autism, infertility, cancer and Alzheimer’s disease.\n\nThat seems sketchy, just reading the abstract...",
"What's dangerous about this study is that that abstract seems to have attitude about it -- as if the people running the study have an agenda.\n\nI think if they had just said, \"we show how interference with CYP enzymes acts synergistically with disruption of the biosynthesis of aromatic amino acids by gut bacteria, as well as impairment in serum sulfate transport,\" that would have been enough to get their point across.\n\nI would never celebrate or discount a scientific paper based on the abstract (or it's tone), however I would only read this paper to get the specific causal effects of CYP enzyme interface and leave the rest of their inferences for the philosophers.",
"\"Exogenous semiotic entropy\" aka a term they made up.\n\nArticle criticizing that paper for bad science:\n_URL_0_",
"Having worked in a wheat genetics lab for 5 years, I can weigh in. Roundup is bad for you if you inhale or ingest it. As is any other fertilizer or pesticide. Spraying it on crops should not affect you. The reason for this is because it isn't sprayed on the seeds (the part that is used) and even when it does, there are regulations for how long you must wait between spraying and harvest. If an unscrupulous farmer sprayed then cut immediately, you may get sick. However the chances of that happening are very very unlikely. Also, many crops have been selectively bred to not need fertilizer or pesticide, that is what my research was about. We would check each breed to see if they carried pest resistant and virus resistant genes so that we could breed stronger healthier and safer crops. "
]
}
|
[] |
[
"http://www.mdpi.com/1099-4300/15/4/1416"
] |
[
[],
[],
[
"http://www.huffingtonpost.com/tamar-haspel/condemning-monsanto-with-_b_3162694.html"
],
[]
] |
|
4sl86p
|
Are all galaxies eventually going to become spiral galaxies?
|
Because of the way gravity works, objects tend to choose a favorable direction and plane of motion. This is why the planets in our solar system all revolve in the same direction and are (as far as I know) on the same plane. Does this principle hold true for galaxies where there are billions of objects which are all massive, and does this mean that all galaxies are eventually going to become spiral galaxies?
|
askscience
|
https://www.reddit.com/r/askscience/comments/4sl86p/are_all_galaxies_eventually_going_to_become/
|
{
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"I believe I've seen somewhere that the oldest (maturest) galaxies are typically elliptical, and that spiral galaxies are theorized to eventually turn into those. When the Milky Way collides with Andromeda that's what we'll be. In fact they say most galaxies today are already elliptical. The spirals are more easily spotted, but when they do a deep field scan they notice that most of the area is filled with elliptical galaxies. \nOn a system that large I'm not sure the motions necessarily have to form an accretion disk, especially if there's no black hole in the middle.",
"It's actually the opposite. Objects will collapse and choose a favorable direction (due to angular momentum conservation) only if there is significant friction during gravitational collapse so that kinetic energy is transformed into heat (and light). So disks only form if most of the matter is in gas rather than stars. If the material is already bound up in stars, there is no friction, so when the star falls to the center it just goes right back out - this is what elliptical galaxies are like.\n\nWhen large spiral galaxies collide, the remaining gas forms stars in one huge burst and the stellar orbits are randomized. The resulting galaxy has no friction, so the stars orbit separately: the galaxy has become an elliptical."
]
}
|
[] |
[] |
[
[],
[]
] |
|
ev9uqf
|
how does isothermal clothing work?
|
I tried looking it up before posting here, but since I am making this post, you can take a guess on how that went. I even tried Youtube and tried searching this r/ but it led nowhere. I couldn't find anything on how it works. Just that there are some more "advanced" pieces with body-mapping technology applied.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/ev9uqf/eli5_how_does_isothermal_clothing_work/
|
{
"a_id": [
"ffuqwqc"
],
"score": [
2
],
"text": [
"Actually I don't think it does. it's just a marketing gimmick. usually, it's a base layer that's made to trap some air between your skin and the clothing (for insulation). in the old days, it was just little dimples they have grander schemes now and haven't found they work any better, it just allows them to use more plastic in the fabric. If they advertise isothermic then it should also lay out the rest of the system and the temperature range it's made to work in. Usually, I find the clothing that does give you the intended use, doesn't necessarily cater to the fashion market."
]
}
|
[] |
[] |
[
[]
] |
|
cuabo0
|
disney world is such a money maker, why are the cities surrounding it so poor with such a housing crisis?
|
Poor Florida.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/cuabo0/eli5_disney_world_is_such_a_money_maker_why_are/
|
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"The thing I would say is that no one who goes to Disney world is really going to stay for a long time in that area. Two I don’t really think any of those theme parks really pay there employees all that much. And most of the area around is full of swamp places.",
"Disney doesn't pay a living wage. Also many of the homes near the park are Air BnBs for the tourists. It jacks up the rental rate for residents.",
"Look into the history of the city of Celebration, FL, and learn the story of Disney's attempt (and failure) at building the perfect city",
"Because that money does not go back to the local economy. It instead gets funneled to corporate accounts, and the corporate team doesn't live in these neighborhoods.\n\nA company doing well only helps the local area if they put the money back in. For example paying workers well, ordering supplies from local companies, making donations to local charities, paying a fair amount of taxes.\n\n\nWhat usually happens is that none of those happen. Workers get low wages, supplies are bought from the cheapest foreign supplier, donations are pretty often less than 0.05%, and they find ways to avoid paying taxes.",
"It allows Disney to leach off of the desperate families by offering them employment but at rates of pay so poor they are unable to move out of their current situation.",
"All the headlines say that central Florida is experiencing an *affordable* housing crisis. This is different from the housing crisis that followed the Great Recession, where lots of people couldn't afford mortgages they had already taken out and lost their homes. This crisis means that some people in the region can't find housing in their price range. You can get in that situation by having a lot of low income people, by having a lot of expensive housing, or both. \n\nCentral Florida isn't exactly the richest region in the US. It's swampy and plagued by heat and hurricanes. Some counties have poverty rates up to 30%, though the areas around Disney World are more in the 15-20% range, so it's unlikely that Disney World is making surrounding communities *less* prosperous (though that's a low bar). \n\nDisney World could be contributing on the supply side. If you are a real estate developer in the region, you will probably get a higher return to building a resort, hotel, or timeshares than you would with inexpensive resident housing. Land is in fixed supply, so every vacation home in that area takes up property that could be use to house residents. This could be compounded with the fact that even if Disney World pays a decent wage, it's paying a lot of people to do relatively unskilled jobs like concessions and janitorial work. Those jobs are necessary, but the people who do them are getting priced out of the areas around their workplace, forcing them into longer commutes.",
"The area around Disney World is not especially poor. Check these maps:\n\n_URL_2_\n_URL_3_\n\nThe Orlando area has relatively low poverty compared to the Florida panhandle or Miami. It's not spectacularly wealthy, but it's not bad either.\n\nThe Orlando area also doesn't have a community-wide housing crisis. Housing prices there are near the national average.\n\n_URL_0_\n\nIt does, however, have a low-income housing crisis. There are very few homes for the very poor. \n\n_URL_1_\n\nLow-income housing doesn't happen by accident in growing cities: opportunities must be created -- or at least permitted -- by the local government, which reflects the priorities of its voters. IMO, Orlando has a low-income housing crisis because it has a whole lot of residents who don't want a trailer park or housing project anywhere near their retirement home."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[
"https://www.realwealthnetwork.com/markets/orlando-florida/",
"https://reports.nlihc.org/sites/default/files/gap/Gap-Report_2019.pdf",
"http://www.nytimes.com/newsgraphics/2014/01/05/poverty-map/index.html",
"https://www.bebr.ufl.edu/economics/website-article/poverty-and-income-florida"
]
] |
|
21u5bi
|
Did radio have a reputation as being vapid or intellectually detrimental, the way TV does today?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/21u5bi/did_radio_have_a_reputation_as_being_vapid_or/
|
{
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"text": [
"I've only come up on this tangentially, but as it turns out: Yes, in the early 20th century there was a lot of opposition to radio as a form. As early as 1923 we start seeing anti-radio editorials such as an op-ed on the Times (of London), by one Douglas Hacking (then MP). In it, he calls \"the wireless\" a \"maddeningly pedestrian diversion...\" that is \"sure to degenerate the minds of a generation of Britons.\" There were multiple bills introduced in Parliament that year calling for the defunding of the fledgeling BBC, and even the outright banning of radio in the UK. Though they were largely shelved due to more pressing issues at the time, it is notable that 1923-24 saw a brief fad in wearing pots or pans, or aluminium foil (Still a fairly new and expensive good at this time) on one's head while listening to the wireless, as those were thought to protect against brain degeneration - not even the threat of brain damage could keep the first generation of radio listeners away from the \"simpleton box\" as it was known! This was also a generational issue, of course; briefly during this period, youngsters were referred to as a generation of \"twentieth-centurials\" who were described (As one article in prominent American woman's magazine *The Delineator* put it) \"self-centered, perpetual children more interested in the goings-on of the newfangled radio box than the real world around them.\" Twentieth-centennials were also portrayed as be selfish, ignorant, materialistic, lazy, and just generally no good compared to the heroic generation of WWI veterans that came just before them.\n\nAcross the pond, the radio was a target for the (rapidly dwindling) temperance organisations that were looking for a new thing to go after, having recently succeeded in getting Prohibition passed. Radio broadcasters were terrified of this, of course - if those temperance people could get Congress to outlaw *drinking,* what chance did the nascent radio broadcasters have? Radio broadcasters in New York, led by the venerable RCA, convened to develop the Hughes Code, a morality code for the radio, which was supposed to allay radio-borne brain damage (By 1925 a major issue in America's national conversation). The sedate, gentle style of Hughes code-era broadcasts is thought to have been a major influence on the early NPR and the genesis of public talk radio, too. By 1926, the panic seems to have subsided as radio became an accepted part of life in the Anglosphere, which is why the notion of putting a pot on your head to guard against radio-borne brain damage is so strange - it came and went in the popular culture very fast, though it remains in the use of \"tinfoil\" as a by-word for lunacy; that got mixed up in popular culture and stuck around, so much so that people are generally unaware of the very real use of aluminium foil to guard against brain damage in the twenties!\n\n**This post was written as part of the AskHistorians 2014 April Fools' prank, and is therefore total nonsense.**"
]
}
|
[] |
[] |
[
[]
] |
||
6ajvml
|
why do most bipedal robots always keep their knees bent a bit when standing?
|
See for example the robots in [this](_URL_1_) and [this](_URL_0_).
As humans, we don't stand like that very often because it would be tiring since we would have to be tensing muscles the whole time, Instead we can rely on ligaments/tendons to support us.
I suppose a robot doesn't have to use energy to keep muscles tensed for that knees-bent pose, but what benefit does it bring to stay in that position and never get truly upright?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6ajvml/eli5_why_do_most_bipedal_robots_always_keep_their/
|
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"I've always been under the impression that it was due to balance. The robot could stand up, but once upright the weight of the bot would make it lose balance as the parts aren't distributed in a way that allows for the robot to stand completely upright.\n\nI eagerly await a more informed answer :D\n",
"Has to do with the way they walk. It's called Zero-Moment-Point movement. Basically they position their legs, so that they do not produce any moment in horizontal direction, thus the robot cannot flip over. The drawback of the calculation behind this is that you cannot allow two axles to be co linear because then you have a singularity that you cannot calculate, because you then have two axles that could cancel out a momentum but you cannot chose which. The easiest solution is to forbid the joint to be stretched. \n\nEdit: To put it more ELI5: IF you have two axles that are in line the robot brain cannot chose which one should move in what direction to make the next step since they have the same direction. So they forbid them to be in line.",
"I'm still an industrial electronics student but if I had to guess I would say that it is because when engineers program robots they are given a \"home position\" that the robot stays in. In this case the home position is the one that best allows the robot to react to varying conditions. Like if the robot were to step into a hole and the knees were locked straight it would have trouble being able to step down into the hole because that joint can't rotate any further. But if the knee is in the middle of its rotation then it can straighten to step down into the hole or rotate further to step up onto something. Basically it's the position that allows a robot to do as much as possible and as far efficiency goes we are still just getting the kinks worked out of getting a robot walking. So it's not the most efficient way to stand but it's the easiest. ",
"Because they are trying to model them off humans, because our bodies have adapted to walking on two legs and the closer we get to mimicking that, the more functional they will be. As humans we actually do stand with our knees slightly bent. Try standing in one place with your knees locked. It gets very tiring very fast, and if you are in a very hot environment or thick clothing, you can actually pass out because of it. I don't know the exact reasoning but it was what they always told us in military school during stationary reward parades. And I saw many a person drop like a fly because they didn't listen and locked their knees. ",
"I'm throwing my hat in the ring for balance, and you kind of touched on this in your question.\n\n-Humans-\n\nThere are several muscles, nerve endings, and neurological pathways that are triggered when we are standing. Our muscle fibers, ligaments, tendons, and nerves are always adjusting to the environmental influences on our steady standing state (knees bent barely bent).\n\nJust like standing normally, when we engage in a straight leg stand, our feet are gripping into the floor/shoes, our ankles are pivoting and compensating, our calf/leg muscles are flexing to keep us upright, our arms continually providing counter-weight (not to mention our brain instructing all of this). You are correct that we don't do this very long, but the same thing happens in both scenarios.\n\n-Robots-\n\nWe don't the same level of complexity in the skeletal/nervous structure; therefore, they have to rely on a level surface and proper weight distribution. With legs straight, there is no opportunity to react to small environmental changes sending that weight to-and-fro.\n\n\nThe slightly lower center of gravity provides much more stability and structure to withstand these forces (for example, think LEGO people - it's tough for them to stand when holding things in their hands, so we have to compensate the weight offset by angling their torso, or just glue them in place ;) ). The more height you have and/or the more weight gravity is having force on, the harder it is to keep upright.\n\nEDIT: formatting",
"Humans _do_ keep their knees bent when standing, just not as obviously. If you \"lock\" your knees straight while standing you'll pass out. This happens to military recruits standing at attention all the time.\n\nIndeed part of learning to stand at attention is learning to keep your knees bent.\n\nBut an average human shifts around constantly in autonomic balance as the pressure in their joints signals reflexes in the spine to adjust posture. This lets us stand in \"much riskier\" postures.\n\nRobots tend to _lack_ this second signaling system and the fast-twitch muscles that make it work. So their designers have them park in a much more stable partial-crouch.\n\nRobots also tend to have larger feet per unit height to ensure a larger range of motion that still keeps the center of mass over the center of support.\n\nTL;DR :: Robots are slower so they need to be more careful, but humans _do_ keep their knees bent while standing still... or they fall down.\n\n_URL_0_"
]
}
|
[] |
[
"https://youtu.be/QdQL11uWWcI?t=123",
"https://youtu.be/GA-M1pMtANs?t=222"
] |
[
[],
[],
[],
[],
[],
[
"https://www.youtube.com/watch?v=Z62esVdmxCQ"
]
] |
|
183qo2
|
how does the body "know" to try and reattach itself to a severed limb?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/183qo2/how_does_the_body_know_to_try_and_reattach_itself/
|
{
"a_id": [
"c8bfofb"
],
"score": [
8
],
"text": [
"Uhm, it totally doesn't.\n\nI'm having difficulty understanding what you are asking, exactly. Like, let's say I am trying to fix my lawnmower when a neighbor kid herpderps over and turns the motor on. Off goes my left hand.\n\nMy left wrist is NOT sending signals to my brain saying \"Look! The hand is right there! Let's reattach!\" All it's sending to the brain is \"Holyshit, a lot a lot of tissue just got severely damaged ow ow ow ow ow,\" or possibly \"Hot damn, you're losing a lot of blood. You should go into shock so you have a fighting chance of getting yourself to a hospital or something.\" Now, assuming you are not blind, your eyes *are* sending your brain the message of \"Lookie, it's right there\" and your brain, which has basically always had the will to live, hatches a plan saying \"I gotta put this on ice and take it to the ER immediately\" and then carries that out.\n\nPotentially you are trying to ask \"Once the doctor puts the hand back in place and sews things up, how do the tissues on the hand \"know\" to line up properly and attach themselves to the tissues in the wrist?\" Well, again, they don't. The tissues in your hand and wrist, provided they are getting adequate assistance from the body (enough blood flow, platelets, infection-fighting white blood cells) will try to heal the wound any way they can. Scabs and equivalent connective tissues will be made by your body and then eventually skin and permanent tissue will grow around/under it until the scabs can go away. If my hand is obliterated in the lawnmower, the end of my wrist will STILL try to scab and heal itself, it will just end up as a nub. If, however, my hand happens to have been professionally medically put back in the right place, then when my body starts scabbing/rebuilding, it will encounter my hand, and the reattachment process will include it. This is also why skin grafts work. The body is scabbing up, and will scab up against whatever is there, an in the case of skin grafts it goes \"Oh how convenient! More skin to scab up against!\" and continue doing its thing. If the doctor effs up the alignment, my body will not just gloss over the error and make everything be hunky-dory again because he was \"close enough.\" I'm gonna lose that hand. And in fact, I probably will anyway. The bigger or more complicated the part you are reattaching is, the less likely it will be to reattach successfully."
]
}
|
[] |
[] |
[
[]
] |
||
6f2foo
|
how does anxiety cause one to experience feeling unattached to one's body, or "derealization"?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6f2foo/eli5_how_does_anxiety_cause_one_to_experience/
|
{
"a_id": [
"difhbk5"
],
"score": [
5
],
"text": [
"It's a coping mechanism; really short answer, dissociation/derealization is a defense mechanism to deal with stress or trauma. Not being there = not having to deal with the stressful situation. If you need me to expand on it I can. :o\n\nSource: I have severe dissociation and dissociative identity disorder "
]
}
|
[] |
[] |
[
[]
] |
||
7e975d
|
why the value of so many western currencies is roughly equal?
|
USD, EUR, CHF, GBP, AUD, CAD, are more or less aligned to a 1:1 ratio, when I don't think there is any economic/financial reason why they should be so. Is it just the result of a convenient choice?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7e975d/eli5_why_the_value_of_so_many_western_currencies/
|
{
"a_id": [
"dq3iz2d",
"dq3j2y1"
],
"score": [
42,
4
],
"text": [
"Many of these currencies are or were pegged to the USD after WWII. Since the United States had the vast majority of the world's gold (lend-lease was expensive, as it turns out), the agreement was that the USD would be backed by gold and the other currencies would be backed by the Dollar. (The [Bretton Woods](_URL_0_) system)\n\nIn fact, France and Switzerland actually followed through on this, redeeming their reserve USD for around $250 million in gold in the late 60's. This of course prompted Nixon to make the Dollar free floating, backed by nothing in particular. (The Nixon Shock)\n\nSince the Euro and Australian Dollar were created after this system, it made sense to value them around 1:1 with the USD. The Pound Sterling and the Swiss Franc were initially valued at around 4:1 with the dollar, but the post war economic boom in America rapidly increased the relative value if American dollars, bringing them more in line with each other. \n\nThe Canadian dollar, on the other hand, was pegged at 1.1:1 in the 40s and has been slightly less valuable ever since. \n\nTL;DR: America had all the gold after WWII and made the rules.",
"That's a great question! I'm sure someone else can give a more complete answer, but it's in part due to the fact that several of these western countries had explicit currency pegs tying their currency to the price of gold at similar rates (so, you could covert dollars to gold at a fixed rate the government set) - read about the Bretton Woods system for more info about that: _URL_0_. For a time several countries also explicitly tied their exchange rates to the US dollar (so, you could exchange that currency for US dollars at fixed rates). This kept the exchange rates relatively stable, and many of these countries chose pegs that were near a 1:1 ratio.\n\nToday, those countries you listed don't have explicit pegs, but the central banks operate in similar ways. Many central banks of developed western countries either formally or informally manage their policies in order to hit an inflation target of around 1-2%. This and the fact that the currencies had similar initial values due to the choice of the previously fixed rates keeps the exchange rates fairly stable as the different central banks have similar goals. "
]
}
|
[] |
[] |
[
[
"https://en.m.wikipedia.org/wiki/Bretton_Woods_system"
],
[
"https://en.wikipedia.org/wiki/Bretton_Woods_system"
]
] |
|
253b43
|
How would schizophrenia manifest itself in someone who was deaf or raised isolated from language? Would the voices be manifested elsewhere in their sensory system?
|
I work with people with disabilities and mental disorders. This intrigues me.
edit: was about to crash when I scrolled past the front page and see my post! thanks for all the input guys this is awesome!
|
askscience
|
http://www.reddit.com/r/askscience/comments/253b43/how_would_schizophrenia_manifest_itself_in/
|
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"text": [
"To add, schizophrenia does not equal hearing voices. Auditory hallucinations are a sign of psychosis, which can be schizophrenia or several other things. And someone with schizophrenia might have delusions, visual hallucinations, loose speech, paranoia, etc., and never have auditory hallucinations. They could be catatonic or have a flat affect. Schizophrenia can present in a number of different ways.",
"Here are a few things to consider:\n\n(1) If a deaf person has visual hallucinations of someone signing to them, this is not equivalent to having delusional thoughts in sign language. In schizophrenia, delusions can arise with or without hallucinating voices or signs, and these delusions have more to do with cognition than perception [(Cuesta & Peralta, 1995)](_URL_0_).\n\n(2) In people who are born deaf, the auditory cortex is recruited to handle processing for other perceptual modalities [(Lambertz et al., 2005)](_URL_2_); therefore, it is unlikely that abnormal activity in the auditory cortex of a congenitally deaf person could manifest auditory hallucinations, and would more likely manifest hallucinations in other modalities.\n\n(3) If someone has never perceived sound, their concept of hearing is solely based on how the experience has been described to them. Even if the random firing of auditory neurons somehow elicited auditory hallucinations in a congenitally deaf person, it would be very difficult to recognize these sensations as sound because they would not correspond to any previous experience [(Mishkin & Murray, 2003)](_URL_3_).\n\n(4) In cases where people with schizophrenia become deaf later in life, whether or not they would continue to experience auditory hallucinations depends on the cause of their deafness; if caused by damage to the basilar membrane, auditory hallucinations would likely persist, but if a stroke destroyed the auditory cortex, they would likely cease to occur [(Lennox et al., 2000)](_URL_1_).\n\n",
"Not all persons with schizophrenia hear \"voices.\" Some have no hallucinations, only disorganized, non-rational thinking. Some have visual hallucinations. If their brains have never heard a sound, then they would not hallucinate \"sounds\" but rather, they might hallucinate thoughts, such as \"You're trying to kill me\", but without the sound.",
"It is worth noting that schizophrenia does not only manifest itself as \"hearing voices.\" Schizophrenia is a very, very complex disease, and only a subset of sufferers have audio hallucinations aka \"hear voices.\"\n\nFrom WebMD:\n \" Paranoid-type schizophrenia is characterized by delusions and auditory hallucinations (hearing voices that don't exist) but relatively normal intellectual functioning and expression of emotions. The delusions can often be about being persecuted by a person or an organization, or feeling harassed or treated unfairly. People with paranoid-type schizophrenia can exhibit anger, aloofness, anxiety, and can be argumentative.\n Disorganized-type schizophrenia is characterized by speech and behavior that are disorganized or difficult to understand, and flattening or inappropriate emotions. People with disorganized-type schizophrenia may laugh inappropriately for no apparent reason, make illogical statements, or seem preoccupied with their own thoughts or perceptions. Their disorganized behavior may disrupt normal activities, such as showering, dressing, and preparing meals.\n Undifferentiated-type schizophrenia is characterized by some symptoms seen in all of the above types, but not enough of any one of them to define it as another particular type of schizophrenia.\n Residual-type schizophrenia is characterized by a past history of at least one episode of schizophrenia, but the person currently has no \"positive\" symptoms (such as delusions, hallucinations, disorganized speech, or behavior). It may represent a transition between a full-blown episode and complete remission, or it may continue for years without any further psychotic episodes.\"\n\nSource: _URL_1_\n\nWith that established, how *do* non-visual hallucinations occur in deaf populations? Here's three articles:\n[Auditory hallucinations in a deaf patient: a case report.] (_URL_0_)\n\n[Identifying and assessing psychosis in deaf psychiatric patients.](_URL_3_)\n\n[[Peculiarities of schizophrenic diseases in prelingually deaf persons].](_URL_2_)\n\nFrom the abstract of the last: \"The article shows that acoustic hallucinations of normal hearing schizophrenic people correspond to visual and tactile hallucinations of the prelingually deaf. An additional similarity is found in a disorder of the structure of the language. These similarities show that schizophrenia does not depend on the acoustic part of language or the acquisition of spoken language\"\n\nI wish I could do better than that, but the article is in German.",
"It depends on their linguistic development. Born-deaf people with schizophrenia report signed 'voices', finger spelled messages, 'shouting' in a visual form etc etc. Our problem is that hearing symptomology defines the disorder and the assessment process and so doctors naive to Deafness often unwittingly teach the patient to report 'voices' when the experience is non-auditory. IAMA Clinical Psychologist with Deaf People.",
"According to a german dissertation \"[Pharmakotherapie gehörloser\nschizophrener Patienten](_URL_0_)\" (\"pharmacotherapy of deaf schizophrenic patients\") deaf people can have hallucinations of hearing voices. (paragraph 1.4.2)\n\nIt's not fully explored how this can be.\nThe deaf people hearing voices have problems to describe it, as they try to describe what actually never happended to them - they heard something - but the description of the patients are so precise that it's handled as actual fact.\n\nBut in addition they often see people giving sign language, too.\n\nOn the end of that paragraph it's mentioned that these evidences could indicate that the theories of hallucinations beeing originated of the combination of nerve stimulus and imagination of the patient are wrong.",
"It all depends on how you understand schizophrenia. There are many theories that have come up since it has been coined by Eugen Bleuler in 1908 (formerly Dementia Praecox from his book Dementia Praecox, or the Group of Schizophrenias). The mad mother theory (purported mostly by R. D. Laing in the 60's) found some relevance, but it became somewhat politically incorrect to blame parents, and psychologists were moving towards a scientific model and away from a philosophical model. I think in the 80's the \"serial invalidation\" theory became popular where one continually denies ones experiences or feelings. This paved the way for a stronger medical model of psychosis, meaning, it is a neurological/chemical imbalance that can be corrected or treated through medication. But all of the models aside, it is all relative to the experiences a person has. If something traumatic happens and the person cannot cope, or struggles to harmonize the experience, it could lead to a type of splitting (schizophrenia means literally \"split mind\"). The split in a deaf person could be his internal and external experiences. Or his relationship with objects and people. His sense of trust his other senses might be lost. I think someone who is born deaf and lacks sufficient language to communicate and with schizophrenia, would be a challenge to treat. You would have to use alternative methods. Talking and meds alone will not do it. "
]
}
|
[] |
[] |
[
[],
[
"https://www.sciencedirect.com/science/article/pii/0165178195027126?np=y",
"https://www.sciencedirect.com/science/article/pii/S0925492700000688?np=y",
"https://www.sciencedirect.com/science/article/pii/S0926641005002715?np=y",
"https://www.sciencedirect.com/science/article/pii/0959438894900736?np=y"
],
[],
[
"http://www.ncbi.nlm.nih.gov/pubmed/23936715",
"http://www.webmd.com/schizophrenia/guide/schizophrenia-types",
"http://www.ncbi.nlm.nih.gov/pubmed/21591325",
"http://www.ncbi.nlm.nih.gov/pubmed/21327903"
],
[],
[
"http://www.zbmed.de/ccmedimages/2011/ZBMED-20114151511-9.pdf"
],
[]
] |
|
a0evuv
|
why does eating more frequently increase your appetite?
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/a0evuv/eli5_why_does_eating_more_frequently_increase/
|
{
"a_id": [
"eah71ie"
],
"score": [
2
],
"text": [
"Simple. You stomach is elastic. Eating a lot causes it to stretch and grow. Not eating a lot causes it to shrink. Your appetite always drives you to fill your stomach, whatever size it currently is, so if you eat a lot, it take more food to fill it since you are stretching it out (and I think it grows if it stretches a lot.)"
]
}
|
[] |
[] |
[
[]
] |
|
125wd3
|
How does blue and red shift of a star occur if light is constant?
|
Hey ask science, I'm confused how blue and red shift occurs if light travels at a constant speed ( not considering certain materials and gravity)?
|
askscience
|
http://www.reddit.com/r/askscience/comments/125wd3/how_does_blue_and_red_shift_of_a_star_occur_if/
|
{
"a_id": [
"c6sffi1",
"c6sfvk7"
],
"score": [
11,
6
],
"text": [
"The wavelength and frequency both change, while the light maintains a constant speed.\n\nThe speed of a wave is equal to the length of a wave from peak to peak times the frequency, or how often a peak passes you as the wave travels by. Redshift corresponds to lower frequency and longer wavelength, and vice versa for blueshift.",
"Think of it the same way as being next to a moving train. As it comes towards you, you hear it's sound get higher. When it moves away from you, it's sound gets lower. The same thing happens with light."
]
}
|
[] |
[] |
[
[],
[]
] |
|
3wkgky
|
Why no aerial oxygen torpedoes for the Japanese?
|
The way I understand it, the Type 93 'Long Lance' torpedo was much deadlier than American torpedoes, because of it's greater speed, range, damage, and difficulty in spotting it. However, damage to the volatile torpedoes could sink destroyers carrying them.
The way I see it, carrying oxygen torpedoes nullifies this weakness, since damage severe enough to detonate the torpedo would down the aircraft anyway, while improving survival rates by keeping the torpedo bombers further from Allied AA screens. Was it just impossible to make oxygen torpedoes small enough to be carried by single engine craft? It just seems strange that they wouldn't play their torpedo advantage to the hilt.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3wkgky/why_no_aerial_oxygen_torpedoes_for_the_japanese/
|
{
"a_id": [
"cxx0a11"
],
"score": [
5
],
"text": [
"The Japanese did develop an experimental oxygen-propelled aerial torpedo, the Type 94 in the early 1930s in parallel with the oxygen-propelled Type 93 and Type 95. The Navy Technical Arsenal found that the Type 94 was too complicated and maintenance- intensive for an aerial weapon. The main advantage of an oxygen torpedo- range- was not nearly as important for aerial attacks, especially since aircraft often lacked the sophisticated and heavy fire-control equipment surface ships and submarines possessed to successfully carry out an attack at distance. Although the Yokusuka and Nagasaki Arsenals produced between 100-200 Type 94s, the Japanese soon went back to conventional aerial torpedoes. The IJN would not revisit the possibility of oxygen aerial torpedoes in no small part because its standard aerial torpedo, the Type 91, gave sterling performance. The Type 91 was superior in performance to its American counterpart at the start of the Pacific War and their anti-roll stabilizers allowed the torpedo to better hit their target. The only serious wartime modifications of the Type 91 was replacement of bronze parts with steel and minor alterations that eased production and boosted performance, with the resulting simplified torpedo, the Type 4, entering production in 1944. "
]
}
|
[] |
[] |
[
[]
] |
|
9tt8me
|
do wifi signals face resistance when passing through walls?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/9tt8me/eli5_do_wifi_signals_face_resistance_when_passing/
|
{
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10,
36,
2,
2
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"text": [
"yes it does, the signal cant go throught too many walls, it get weaker everytime and if you got heavy duty old walls (like 1m thick) it doesnt go throught at all\nthe medium absorb more energy than the air and the signal is gone",
"If you think of the WiFi signal like a stream of water coming from a hose and the wall like a mesh screen, when you point the stream coming from the hose at the mesh, most of it goes through but the stream is slightly degraded. The thicker the wall or the make up, is it a wooden wall a concrete one a steel one, etc., then the tighter the mesh so the less water goes through. ",
"Yes, but walls aren't always the big issue!\n\nWaves can be absorbed by walls, reflected off of surfaces like windows and metal panels, and they can be grounded really easily.\n\nI used to do a bit of RF work and we found the biggest thing that hampered us was either metal fences (didn't matter that they're full of holes, they act like antennas and ground the shit out of it) and even trees, which behaved similarly.\n\nOften times walls (even fairly thick ones) aren't the biggest deal breaker.",
"They can also be more hampered by plaster walls than by sheetrock because some plaster walls contain a wire mesh. I live in an old apt building with those kinds of plaster walls. My computer is only probaby about 40/50ft from our router, but it passes through 3 walls. The signal was terrible, and sometimes not present at all. I had to buy a 100ft Ethernet cord and wind it all the way to my room. ",
"Man, do they. I live in a pretty old house. So the walls are all plaster and chicken wire. I barely get WiFi in my room that’s like 20 feet from the router. "
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
||
4bh2ir
|
how exactly does a power strip work?
|
How can you plug in multiple different things into the strip without it overloading on power or something . . . ?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4bh2ir/eli5_how_exactly_does_a_power_strip_work/
|
{
"a_id": [
"d190in1",
"d190kia",
"d19cn38"
],
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51,
7,
5
],
"text": [
"The outlets in a power strip are wired up in parallel. As you plug more items in the load does increase. Most power strips have a circuit breaker on them that will trip if you exceed the load, if not your outlet should have a circuit breaker as well. It is entirely possible to overload a power strip, it is just most consumers don't have that many high draw items in one area and professionals such as contractors already know better.",
"You power outlet has a maximum load, usually (but not always) 16A - which corresponds to 1760W with 110V and 3680W with 230V. If the power draw on an outlet is higher than that, the heat dissipated in the wiring would be too high, and therefore the power strip should have an overload protection which cuts power if power draw exceeds the maximum.\n\nSo if you are in the US and have a vacuum cleaner and kettle with 1500W each, and you connect them to a single power brick, it should cut power before anything serious happens.",
"Electricity is like a road network of copper where each each group of electron travel in that road with the same load, 120V. Each road has a capacity in group of electron per second (A). If there is too much amperage, the road melt and it is unusable. \n\nPower strip just prolong the road with more exits, and that can bring more amperage to the network, which can not only be over capacity for the strip, but also the plug it is been plugged in."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
dnz1ac
|
how are our intestines able to sort between gas, liquids and poo?
|
And what are the mechanisms that allow to distinguish whether we are going to fart or poo?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/dnz1ac/eli5_how_are_our_intestines_able_to_sort_between/
|
{
"a_id": [
"f5ijmxw"
],
"score": [
3
],
"text": [
"Liquid is extracted by the large intestine. Essentially the large intestine has chemical pumps that take advantage of osmosis to force water out of the intestines and into the body. Salt is pumped into the liquid between the cells and this causes osmosis to push water into that liquid and from there the bloodstream. \n\nThis leaves solid wastes and gases (which comes from swallowed air and gut bacteria). The large intestine has nerves in it, which essentially allows us to feel what's in our large intestine. Gas and solid waste behave differently and over time we learn to feel the difference."
]
}
|
[] |
[] |
[
[]
] |
|
239hzn
|
how does a surveying work?
|
I see people surveying at construction sites all the time, but I have no idea what they are actually doing. What is that thing on the tripod? And what are they looking at?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/239hzn/eli5_how_does_a_surveying_work/
|
{
"a_id": [
"cgurz60"
],
"score": [
3
],
"text": [
"Basically it is a measuring device to measure angles and distances, and elevation.\n\nSo a building is designed on a computer model of the site. You need a way to take that electronic information and place it on the real ground so the guys actually building the building know where to build the building, or the new road or whatever.\n\nThe thing on the tripod is kinda like a telescope, it has cross hairs and can measure very precise angles and distances, the newer ones are robotic and use gps.\n\nSurveying also works the opposite way, you can measure stuff on the ground and recreate it electronically on a computer."
]
}
|
[] |
[] |
[
[]
] |
|
261ubq
|
Will swirling my coffee in it's cup cool it down faster, slower, or have no impact?
|
I imagine the coffee hitting the upper 'walls' of the cup and thus transferring energy to it, but maybe the swirling causes friction and thus, small amounts of heat?
|
askscience
|
http://www.reddit.com/r/askscience/comments/261ubq/will_swirling_my_coffee_in_its_cup_cool_it_down/
|
{
"a_id": [
"chmwak6",
"chmwfjz"
],
"score": [
2,
2
],
"text": [
"faster, the coffee is in contact with more of the cups surface area, plus more evaporated cooling, and mixing the hottest coffee at the top with the coolest from the bottom. If you're using a metal spoon, it'll absorb some heat too.",
"The coffee should cool more quickly. Reason being that as the liquid transfers heat the cup, and evaporates off the top. the coffee on the sides and top is colder, and the temperature difference narrows, slowing conduction and evaporation cooling. by swirling, you get an even distribution of heat, so the coffee on the sides and top is as hot as possible, so the temperature difference between the cup and coffee is as great as possible.\n\nEdit to add: a way to test this would be to get a digital thermometer and stopwatch. pour boiling water into a cup, and pick a temperature to start off. say, start the stopwatch when the temp reaches 90 C, then take readings every minute. repeat the experiment while stirring. for better data, do several trails of both the experimental (stirring) and control (no stirring)"
]
}
|
[] |
[] |
[
[],
[]
] |
|
4e6gc1
|
why does it take some people longer than others to be alert upon waking? as in, why does it take some people longer to really "wake up"?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4e6gc1/eli5_why_does_it_take_some_people_longer_than/
|
{
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"d1xi7he",
"d1xj6s9"
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21,
44,
8,
101
],
"text": [
"Great question, I would actually like an in-depth science explanation though. I very recently switched from being a snoozer to just getting up when the alarm goes off. So I'm getting up at the exact same time every morning. It's so much easier to get up now after about a month and I'm more alert than before. \nThis works well even if I've been up late the night before. ",
"I think it depends on which sleep cycle you're in when you wake up. If you wake up in your Rapid Eye Movement(REM) sleep it will take longer to wake up fully and you may feel groggy for the rest of the day. But if you wake up in between or even on your own it is easier to become alert. ",
"My wife laughs at me about this. When something happens suddenly, like an earthquake or a car crash, I jump out of bed and hop into action well before I'm awake. It's cool and everything, except in those cases when it's not really an emergency, like when she accidentally banged something against the bed frame and asleep me thought it was an earthquake. I had my robe on and was halfway out the room before I realized she was calling my name. ",
"Cortisol production also has to do with this. Some people make more cortisol in their sleep. These people tend to appear to \"snap awake\"... _URL_0_ (edit: I just woke up and forgot to link to the wiki-sauce)."
]
}
|
[] |
[] |
[
[],
[],
[],
[
"https://en.m.wikipedia.org/wiki/Cortisol_awakening_response"
]
] |
||
5x7fk4
|
the artistic value of rothko's orange, red, yellow painting
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5x7fk4/eli5_the_artistic_value_of_rothkos_orange_red/
|
{
"a_id": [
"deg19eq"
],
"score": [
2
],
"text": [
"Like everything else, something is worth what another person is willing to pay for it. A sub that focuses on art work might be a better place."
]
}
|
[] |
[] |
[
[]
] |
||
1sdwtf
|
What is the current historiographical opinion regarding Henri Pirenne's: Muhammad and Charlemagne.
|
A while ago I read Pirenne's *Muhammad and Charlemagne* and thought he gave a very convincing argument. My understanding is that Pirenne wrote his book *Muhammad and Charlemagne* arguing that Western Rome did not fall in 476 but later in the 8th century with the rise of Islam. Control of eastern trade by Islamic states prevented the flow of goods to Western Europe which in turn lead to economic decline.
I was hoping someone with more knowledge of the area could explain: Which parts of Pirenne's thesis are currently supported (and which parts are not)? How useful is this thesis in explaining early medieval political state formation? What alternatives out there are there to Pirenne's thesis.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1sdwtf/what_is_the_current_historiographical_opinion/
|
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"\"Without Mohammed Charlemagne would have been impossible\"\nFamous words. But does the evidence support it?\n\nI've actually just read a fascinating work that deals with some of Pirenne's concepts in depth. Have you heard of Power and Plenty? The author states that Pirenne's thesis, while attractive, is not effectively backed by the evidence. \n\nI'll paraphrase the author's response: Pirenne summarizes Islam's effect by noting the disappearances from Western Europe of papyrus, luxury fabrics, spices, and gold. However, these disappearances either did not occur, or are a result of causes aside from the great Islamic conquests. Papyrus was still found widely in Italy, and its reduction in use throughout the Western world might better be attributed to a loss in the need for legal record-keeping. More troubling still for Pirenne's thesis is the question: why on Earth would the Arabs have even wanted to restrict trade with Europe? They certainly happily commerced with the nomads of Central Asia, the Hindus of India, and even with their Great Enemy, Byzantium. Why would Western Europe be an exception to this rule? \n\nIt is more likely a great deal trade was rather *redirected*, through everyone's favorite warrior-merchants, the Vikings, who would also incorporate products of the north such as furs, honey, and wax. This is known as the Bolin thesis, and is more widely accepted as a cause of the many moves in European power during this period. ",
"In a nutshell (because the non-nutshell version would stretch across several already written books):\n\nWhat holds:\n\n* The Arab Conquests absolutely cemented (as one could argue that the Persian conquests did their number already) the breaking of the Mediterranean economic system, with catastrophic effects on the urban and political structure of what was left of the Eastern Roman Empire, as well as causing economic regression in southern France, which at the time was still somewhat integrated with the Mediterranean network.\n\nWhat doesn't (keeping in mind almost all of Pirenne's ideas were pre-archaeological):\n\n* Pirenne uses documentary luxury trade evidence as a marker for economic vitality in the pre-Arab conquest Mediterranean. More modern analysis uses pottery, which shows a drastic reduction in volume and regional scope of trade even before the Arab conquests.\n* He overestimates the vitality of North Sea trade. Though it clearly started growing in the time of Charlemagne, in Pirenne's visualization it was already something akin to a proto-Hanseatic League that continued on into the high Middle Ages. Later archaeological digs have found that North Sea trade quickly collapsed after the death of Charlemagne, taking a few centuries to return to the same level.\n* His idea of Germania as Romania is too much of an overextrapolation of \"possible\" de jure Roman authority rather than a reflection of the power situation on the ground, which is that the Germanic successor states were already so heavily regionalized that Constantinople had at best a distant legitimizing influence akin to what the Queen of England has on the policies of Commonwealth (and ex-Commonwealth) nations, which is to say almost nil. \n\nWith that said, Pirenne has absolutely been used as the starting point for analysis of the period, and I would dare say that Peter Brown's promotion of the phrase \"Late Antiquity\" over \"Early Medieval\" is a direct consequence of Pirenne's theory.\n\n(Though with that said, Late Antiquity clearly has a Mediterranean connotation, whereas Early Medieval is much more Western Europe. I have yet to find a periodization name that suitably covers the entire post-Roman European/Mediterranean/Near Asian transition.)\n\nWhat's really interesting is that despite Pirenne's flawed thesis, it has had an amazing durability as a start point, so much so that it's taken until the last 10 years for anyone to come up with an alternative framework for the entirety of post-Roman transition. \n\nBest as I can tell, the only person so far (who has explicitly said he has sought to create a new framework beyond Pirenne) would be Chris Wickham, in his book \"Framing the Early Middle Ages.\" I've seen this book cited everywhere, even as far as East Asian studies on state economic structures. \n\nIn yet another nutshell, he tries to reorient the discussion away from specifically the Arab conquest break in Mediterranean trade, and more toward the collapse (or survival) of regional taxation as a key to the survival of a post-Roman state.\n\nYet despite his explicit statement of seeking to establish a new paradigm (god I hate that word, but I can't find anything else in the thesaurus), he plainly acknowledges the debt owed to Pirenne for coming up with an economic, as opposed to a purely political (barbarians took over the leadership), reason for Roman collapse.\n\nOnly thing about the book, is despite its solid scholarship, you see particular Marxist interpretations pop up every now and then. For example, in the idea that the demographic collapse of Europe was due to voluntary peasant population reduction. Or the assumption that peasants would prefer a life of poorer autonomy to one of relatively greater material wealth but under subjection. I also have issues with his suggestion of monolithicness (and this may just be the nature of Marxist philosophy) of aristocratic attitudes toward the peasantry, as well as vice versa.\n\nBut other than these criticisms, no one debates the quality of the scholarship and subsequent analysis. His examples regarding state collapse or survival are useful enough to be extrapolated or tested elsewhere, which is why you're seeing it in other areas like East Asian, which is attempting to see if his theory holds up with regards to state survival/collapse in that region.\n\nBack to Pirenne. One thing of note that I've read recently. The Pirenne quote \"without Mohammed, Charlemagne would be impossible\" is seen quite often, however it is extrapolated for a wide range of purposes. It should be remembered that the context of that quote in Pirenne's book is specifically religious (the need for a Christian antipode to Islamic caliphs), as opposed economic (i.e. the breaking of mediterranean unity by the Arabs), despite the obvious economic repercussions Mohammed had on the emergence of Charlemagne.\n\nHope this helps, let me know if you have any other questions. ",
"The problem with Pirenne is that he simply did not have the sort of archaeological evidence necessary to engage with this period on a more than, to show my bias, somewhat superficial level. That is, he could look at the way laws were used and promulgated, he could look at titulature and civic organization, he could to an extent track luxury good trade and he could look at historical narrative. This is all useful and necessary to a point but, to use a bit of an odd analysis, is a bit like assessing North Korean economic performance using nothing but official government reports, and so it is difficult for him to make a connection to grounded reality.\n\nSo what he could see is that everyone was still basically presenting themselves as Roman--they were still passing Roman laws and even to an extent following the Roman model of civic aristocracy. However, archaeology very clearly documents a collapse in material sophistication, civic organization capabilities, and in trade routes. This was not, by any means, immediate (except in Britain and a few other places) but it was still very real. It is best to think of the period of one of fragmentation, in each each of the actions of the political organizations had sort of crackling reverberations, decreasing unity and economic integration, further contributing to the material decline.\n\nThis, naturally, only applies to the West. The Eastern Mediterranean maintained its cohesion for some time, and in certain areas flourished as the loss of trade contacts with the West forced greater economic intensification in what were previously marginal zones (the dead Cities of Syria are a prime example of this), and some have indeed argued that the Arab conquest is what eventually broke this economic zone. I can't comment on this, but I think it is important to stress how the East didn't simply continue unaffected, as from a simple political standpoint there is an enormous difference in the power relations between it and its neighbors between Heraclitus and, say, Julian the Apostate.\n\nThere are opposing theories to this, of course, but I am going to be a little dogmatic and say that the nature of our sources *demand* that the material evidence sets the bounds for our interpretations of the period. Seeing that people still read Virgil and called themselves \"consul\" is all well and good, but ultimately describes only presentation and individual cases.\n\nThe leader of this interpretation is Bryan Ward-Perkins' *Fall of Rome and End of Civilization*. It isn't completely uncontroversial, but the only real arguments against it I have seen are that it doesn't account for the East, which I find to be somewhat nonsensical, both because the book is focused on the West and because the model of political disintegration leading to material collapse works quite well in explaining the different outcomes of the East and West."
]
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[] |
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[
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1kcopa
|
what is "dutch disease"?
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explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1kcopa/eli5what_is_dutch_disease/
|
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"The Dutch can breathe easy, because, contrary to popular belief, Dutch disease is not a flesh-eating disease in the Netherlands.\n\nIt's an economic term used to describe an indirect relationship between the usage of natural resources and agriculture. Exploitation of natural resources increases, agriculture declines. Now, why is this? Because the more and more money you make from natural resources, the stronger a country's currency can be compared to other nations. Because of this, a country's *other* exports become more expensive for different countries to buy, which makes the agricultural market much less competitive, thus causing a decline in the sector."
]
}
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[] |
[
[]
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3hdt04
|
what is canon?
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Not the camera manufacturer, the literary term. How is something canon or canonical?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3hdt04/eli5_what_is_canon/
|
{
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"The term was largely used when referring to the Bible. The many authors whose writings appear in the Bible wrote many other things as well. The pieces deemed \"The Bible\" were democratically selected by high ranking clergy. These are referred to as \"Canon\", while the many other writings of biblical authors are deemed \"apocrypha\" and most religions basically think that the canonical writings are inspired by God and for some reason that the apocryphal texts were not. They were mostly excluded because clergy didn't like what they said.\n\nAnyways, \"canon\" is used to refer to the \"official\" part of a story, while other related texts that take place in the same world but aren't \"official\" are \"apocryphal\". For example, many authors wrote stories that took place in the Star Wars universe, but George Lucas didn't read and approve every word, so they are consider non-canonical. "
]
}
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[
[]
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2vhcl5
|
why obama is criticized for going golfing?
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Is he supposed to stay in the Oval Office 24/7?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2vhcl5/eli5_why_obama_is_criticized_for_going_golfing/
|
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"text": [
"It's part of the partisan bickering that comes with a two party system. If the President is a member of your party and takes a break, he's been working really hard and deserves it. If he's a member of the opposition, he's a lazy bum. ",
"Thats what everyone expects, why should he have a small bit of a normal life is what they are thinking",
"People like to criticize for anything and they forgot he is a person who should get to choose what he does with his own free time away from his job.",
"Just like how Democrats and news agencies criticized GW Bush for spending a lot of vacation time at his ranch, Obama is criticized by his opponents for taking his own time off. No matter the president, his opponents will reach for anything they can hold against him.\n\nOf course, Bush actually did set the record for most vacation time ever taken buy a President. I haven't actually seen stats for Obama's time off, but I'd be interested to know how comparable they are.",
"Well, it's a bit funny when coming from the republicans as George W. Bush took way more vacation days.\n\nBush had an average of 128 vacation days per year. Obama has 27 days per year(as of the middle of last year). Yes that is a different of 101 days per year:P"
]
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[] |
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2q9nj3
|
how can windmills compare to nuclear powerplants, where the generators spin with thousands of rounds per minute?
|
And windmills rotate with less than 50RPM.
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explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2q9nj3/eli5_how_can_windmills_compare_to_nuclear/
|
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"Windmills produce less power, that's why you build more of them",
"Simple. With a gearbox.\n\n_URL_0_\n\nYou hook up the slower spinning big gear connected to the wind facing turbine and a smaller gear to a generator and presto. The generator spins faster. You can repeat this with a series of gears and have the generator spin at an optimum rpm.\n\nThe amount of energy you generate isn't dependent on how fast you can spin a generator though, or at least only part of the equation. It also depends on the capacity of the generator in terms of how large it is, how much copper winding it has, etc... and the ability to turn that generator depends on the force the generator is provided. "
]
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[] |
[] |
[
[],
[
"http://auto.howstuffworks.com/gears.htm"
]
] |
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4ilgbo
|
how does "trading futures" work? i've been told it's a good and cheap way to play the stock market, but everything i've read on it confuses me even more.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4ilgbo/eli5how_does_trading_futures_work_ive_been_told/
|
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"Futures are contracts. You agree to buy or sell a certain amount of something (stocks, commodities, whatever) on a date in the future at a price you agree to now. You are betting the movement in price between now and the contract date is favorable to you. If you are selling, you are betting the price will fall, so by setting a price now you will get more than whatever it will be worth on the day. If you are buying it is the opposite. You are betting the price will go up so you are locking in today's price.",
"So I come up to you and say I will deliver to you, a ten pound ready-to-eat turkey on November 22nd if you give me $50 right now... and you think \"that's a good price\" and you give me fifty bucks.\n\nI have just sold you a future comodity or service. We have just performed futures trading.\n\nNow I've sold you that promise. I owe you a Turkey. But I don't have a turkey yet. And if I had a ready-to-eat turkey right now then it'd be inedible in six months anyway.\n\nSo I have six month's to arrange for a turkey to show up at your door on the 22nd. If I can make it happen for under $50 then I made a profit. If it costs me $65 then I lost 15 bucks.\n\nNow lets move to something that could survive six months. Something like a barrel of oil. If I have someplace to store that barrel of oil _and_ I have a way to deliver that oil, then I can buy it at any time and store it.\n\nSo I sell you a barrel of oil for November delivery, for $50 right now. I am betting that sometime between now and then I can get that barrel for less than $50. And Ideally I can just go and have the oil guy deliver \"my barrel to you\" at the requested time.\n\nSo you can go out and arrange for your power plant or refinery to receive 500 barrels of oil a day for all of the foreseeable future, weeks, months, or even years in advance. And the people you bough it from already got the money and are on the hook. If you've got a year's worth of oil lined up at $50 a barrel and the prices rise to $100 a barrel it's my problem not yours.\n\nOther things can work this way too. You can buy my winter corn crop today. I promise you 1,000 bushels of corn and you give me money. I use that money to buy the seed now and grow the corn. I'm on a hook for that 1,000 bushels, it's already sold. But if I can produce more, or produce it for less than you paid, then I make money.\n\nSo \"futures\" are bets on future prices and availability. If I think something is going to be cheap and you think it'll be expensive, you buy from me at a price that's less than you think it will cost, and a price that I think is high. ~~And if we are both right we've spread the risk and the reward.~~ (EDIT: we can\nt both be right enough to make a split profit.) Its essentially impossible for us both to be right or wrong at the same time.\n\nSo most of the stock and commodities markets are just bets. Seller is betting the price will go down, buyer is betting the price will go up.\n\nShort sales and futures sales are just making the bet before you have the item on hand.\n\n(\"Short Sales\" is sort-of like futures trading. Your broker lends you stock to sell right now, and you have to return that stock by buying some of that same stock by a fixed future date _and_ you have to pay a fee for the loan. But both are about selling things now that you'll have to buy in the future. The flaming disasters happen if, by that future date, _nobody_ is selling what you need to buy to make good on your promises.)\n\nIt's higher risk. (What happens if all the corn dies from blight?) but that risk _can_ net higher rewards.\n\nIt's only cheap for as long as you don't lose big."
]
}
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[] |
[
[],
[]
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34hta2
|
how does the brita filter detector work?
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I'm talking about [this thing](_URL_0_). It's not connected to the filter and the underside of it is just a plastic backing. How can it be deciding how fresh the water filter is?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/34hta2/eli5_how_does_the_brita_filter_detector_work/
|
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"Its just a timer, programmed with the average lifespan of a filter that is reset when you put a new filter in, nothing magical. Make sure you reset every time you change filters or it gets confusing!",
"it counts the number of times you tip the pitcher. it assumes that on average each time you tip it forward another glass of water has been poured out (and the LED will blink). the filter life is about 40 gallons, so it predicts when you've gotten close to the end of the useful life of the filter.\n\nwhen the yellow LED starts to blink you have about 2 weeks use (on average) left. which means you should have another filter ready.\n\nwhen the red LED blinks each time you've reached the average useful life for the filter. of course its all pretty imprecise, and it varies depending on whats in your water (sediment or hard water will cause the filter to become too slow to use sooner). \n\nin any event, after two months they suggest you replace the filter.\n\nBTW: you only need to press the RESET button when you install a new filter, not each time you refill the pitcher with water."
]
}
|
[] |
[
"http://imgur.com/O1vAP02"
] |
[
[],
[]
] |
|
1zvicm
|
how bi-planes are able to time/shoot their guns without the bullets hitting the propellers.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1zvicm/eli5_how_biplanes_are_able_to_timeshoot_their/
|
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"In the very earliest aircraft, they wouldn't shoot at all. Aircraft were used for reconnaissance, not for fighting, and pilots of aircraft on opposing sides would wave at each other as they flew past each other.\n\nThen, people started to figure out that, if they had guns, they could shoot down the other side's aircraft to prevent them carrying out their reconnaissance. But shooting had to be done sideways, so that you didn't shoot your propeller.\n\nEventually, the [gun synchronizer](_URL_0_) was invented. This times the gun's shots so that they went between the propeller blades, and allowed pilots to shoot forwards for the first time.",
"As others have said they invented a gear to fire between the props. The machine guns were turned into semiautomatic guns that were fired by the props. The props would send a signal to the gun to fire when it was out of the way. This would fire 1 bullet. This technically means that they were no longer machine guns.\n\nHowever, there were other methods. One involved reinforcing the props with metal and angling them and just letting bullets hit them. This did result in planes shooting themselves down.\n\nAnother method was to put the guns on top of the wing above the pilot so it fired over the prop. \n\nAnother was to put in a second seat and that person would have a gun that could fire to the sides and rear.",
"While all of the responses so far are good (the wiki link explains quite well in-depth, with illustrations), I'd like to try making this as ELI5/TL;DR as I can:\n\nThe pilot's trigger is not really the same as a trigger on a handgun - it does not make the weapon fire. Instead, it works more like a safety - when pressed down the safety is off. The trigger is attached to the propeller - the propeller will pull the trigger each time it is in a position where the bullet will miss.",
"In some earlier cases, there were actually wedges attached to the back of the prop to deflect bullets that were fired at the wrong time."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Synchronization_gear"
],
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[]
] |
||
21fvk8
|
Are there any accounts of interviews with people who participated in lynchings 20, 30, or 40 years later?
|
Not specifically those intervals, but significantly after the event.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/21fvk8/are_there_any_accounts_of_interviews_with_people/
|
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"Yes, contemporary interviews exist documenting the perspectives of those who participated, witnessed, in rare cases even those that survived lynchings. Interviews taking place some decades later are more difficult to find, but can be found in a few cases. \n\nA powerful example comes from the [lynching of two men in Marion, Indiana](_URL_0_), in August 1930 [link NSFW]. The two men were accused of raping a white woman, the typical crime associated with lynching. A third man also accused of the crime was to be hung alongside them, but the crowd spared him at the last minute. The survivor told his story in an interview sometime in the 2000's. It makes for a powerful account - you can find it [here](_URL_2_). \n\nInterviews from perpetrators of these crimes are more difficult to find, especially in the decades after the passage of the major civil rights acts authorizing federal prosecution even decades after the crimes were committed. One major and famous exception involved perhaps America's most infamous lynching - the murder of [Emmett Till](_URL_3_) in 1955. After an all-white jury found Roy Bryant and J. W. Milam innocent, they [told their story](_URL_4_) to *Look Magazine* and in the interview the two essentially admitted to the murder. [Double jeopardy](_URL_1_) prevented future prosecution. "
]
}
|
[] |
[] |
[
[
"http://media.npr.org/assets/news/2010/08/06/lynch-db2a1722a61a2ea2e98a0cc7e20300a12023b7af.jpg",
"http://en.wikipedia.org/wiki/Double_jeopardy",
"http://www.npr.org/templates/story/story.php?storyId=129025516",
"http://en.wikipedia.org/wiki/Emmett_Till",
"http://www.pbs.org/wgbh/amex/till/sfeature/sf_look_confession.html"
]
] |
|
85xose
|
why is it unhealthy/more difficult for hunger’s sake to eat a 2000 calorie breakfast instead of lighter meals throughout the day?
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/85xose/eli5_why_is_it_unhealthymore_difficult_for/
|
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"Your body doesn't need 2000 calories all at once. If you eat a single 2000 calorie meal, then your body will use however many calories it needs at that moment, and then store the rest as fat to be used later. However, when you need calories a few hours later, it won't immediately dip into your fat reserves. Instead it makes you feel hungry. Your body would rather turn fresh food into energy than stored fat. \n\n",
"It's neither unhealthy nor inherently difficult, the fact is you've simply adjusted to eating throughout the day. You could adjust to eating all at once if you stick with it long enough (or eating more often).\n\nThere are some theories about timing your meals for optimum absorption and use of macros and nutrients, but at the end of the day the difference is either negligible or only useful in a case by case basis. All else equal, given time you'll likely notice no significant difference eating all your food at once or spread throughout the day. If you're one of the people who would notice a difference, you'd likely be advanced enough in nutrition to not be asking. "
]
}
|
[] |
[] |
[
[],
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|
73sivg
|
Would it be possible to create helium-4 by introducing helium-3 to a neutron rich environment?
|
askscience
|
https://www.reddit.com/r/askscience/comments/73sivg/would_it_be_possible_to_create_helium4_by/
|
{
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"text": [
"Yes, but this wouldn’t be a very good way of doing it. Most helium in nature is helium-4. So you’d have to gather helium, enrich it with helium-3, and then use the helium-3 to breed helium-4. Unless you have a source of helium which is already enriched in ^(3)He, and want to convert it to ^(4)He for some reason."
]
}
|
[] |
[] |
[
[]
] |
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7pisr5
|
why is it scary when kids sing or laugh or say nursery rhymes in horror movies/games?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7pisr5/eli5_why_is_it_scary_when_kids_sing_or_laugh_or/
|
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"I'm speaking with no actual knowledge on the matter, but I would guess that it's mostly context. There is almost always extremely creepy sounding atmospheric music and/or visuals accompanying the children's voices. I think it's partially just the tone of the scene, and partially the juxtaposition of the sounds of children saying/singing things that would normally be joyful while at the same time, very disconcerting notes and sounds are playing behind it, often accompanied by suspenseful/scary/unnerving events occurring on-screen. There very likely is a defined psychological reason that it bothers us, but I don't know what it is.",
"Generally, it's done in a minor key where the tune is altered, so anything can be spoopy when done that way (Have you seen the Teletubby episode in black and white that plays a Joy Division Song over it?). \n\nAlso, one of the early films to do this was Nightmare on Elm Street where kids are jumping rope and singing 1-2 Freddy's coming for you, 3-4, better lock your door. \n\nIn this case, it's contextual. Freddy Kruger was a child molester and murderer, so it's about dead kids, and the context makes it spoopier.",
"Honestly, kids are just fukin creepy. And when they are used for actual creepy purposes, they turn up to 11",
"its a really old trope\n\npeople used to think you could give birth to demon babies, and obviously that terrified people. that fear was used in art, and that art influenced more art, which in turn influenced more art.\n\nthe fact is, anything can be made scary. you are probably scared of sharks, or at least know someone who is. however, you've probably never heard of anyone who is scared of catfish? why is that? they are about as dangerous as sharks, don't look too much different than sharks (just a big ol fish), and have razor sharp teeth. but art has made sharks scary - despite the fact that only about 1 person in the us gets killed by one ever two years. for the record, 10 americans die every day in the us from drowning - meaning that the water itself is far more deadly than the sharks within it.\n\nso once people got the idea that it made sense that kids should be scary, it was pretty easy to make them scary. ",
"It's the incongruity of horror and innocence. Vsauce did a good video on [creepiness](_URL_0_). It' similar to humor, where two seemingly exclusive ideas are justaposed. But in humor, they are resolved harmlessly. When something is creepy, your brain keeps you wary because it senses a potentially dangerous signal, but also has a conflicting signal that something may be safe.",
"Children like animals are the harbingers of doom. They are apparently ignorant, yet in their ignorance their minds are open to the bizarre such as the supernatural. \n\nChildren being weird. Dogs acting up. Sudden flock of birds.... Ghosts are coming!",
"For me kids general don’t have a moral compass or at least it’s not fully developed. So there is no telling what they are capable of even playing or something. Mix that with atmosphere and the kids having other worldly abilities. Nope nope nope!"
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[
"https://www.youtube.com/watch?v=PEikGKDVsCc"
],
[],
[]
] |
||
2u25ly
|
Can electrons from a particular atom be anywhere in the universe but statisticaly nearly always in a definite zone near the core or there is places those electrons can't be?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2u25ly/can_electrons_from_a_particular_atom_be_anywhere/
|
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"text": [
"Electrons can not exist within nodes. The number and shape of nodes is dependent on the orbital angular momentum. ",
"You do have orbitals that can get very far from the nucleus, but for large distances away from the atom you would need to use relativistic quantum mechanics to calculate the chances of finding the electron there. Fun Fact: Using non-relativistic quantum mechanics and assuming the universe was was infinitely big, then statistical physics would predict that an electron would have zero chance of being in any given orbital around a hydrogen atom and it would be spread over a nearly infinite volume. Here is a discussion: _URL_0_",
"They would still be limited by their light cones, which I think would be set everytime they are observed or interact. So this would basically limited them to a sphere with radius set to number of light seconds equal to number of seconds since the last interaction.\n\nOtherwise, this would break causality and relativity.\n\nTo answer your underlying question though, yes, they could be found anywhere in that light cone. (with nearly impossible probability)",
"Well the electrons in any atom are the reason the reactions happen, meaning that in a reaction there will be electron transfer and the electron from a metal will \"be a part\" of the anion. The electrons do really belong to a specific atom as they can always move around during a reaction. Also for where exactly the electron could be found is determined using atomic orbitals. The atomic orbital is basically a probability calculation of where the 1st, 2nd, 3rd etc. electron could be found in an atom depending on the number of electrons found in the neutral state of the atom. Hope that helps. "
]
}
|
[] |
[] |
[
[],
[
"http://scienceblogs.com/builtonfacts/2011/01/25/the-hydrogen-partition-functio/"
],
[],
[]
] |
||
xbbw1
|
Is squinting actually bad for your eyesight?
|
I tried googleing it, but I couldn't find anything useful.
|
askscience
|
http://www.reddit.com/r/askscience/comments/xbbw1/is_squinting_actually_bad_for_your_eyesight/
|
{
"a_id": [
"c5kvazr"
],
"score": [
2
],
"text": [
"I don't know if it's bad for your eyesight or just a sign of bad eyes. Squinting will improve peoples vision slightly if they have bad eyesight which is why you might see people do that if they lost their glasses. Because of this reason it might have also made people think it was the cause of them needing glasses when it was simply their body compensating for their bad vision up until they got glasses. \n\nAlso, squinting can help protect your eyes. Squinting in bring light is your bodies response to light so bright it could harm damage your retina. Squinting will limit the amount of light entering your eyes preventing/limiting damage until your eye compensates by making the iris smaller or until the light source is removed. "
]
}
|
[] |
[] |
[
[]
] |
|
7fwyj9
|
Operation Barbarossa caused massive Soviet casualities/incredible success for the Germans yet failed in capturing Moscow or force a surrender, was there a glaring tactical error that prevented this?
|
Much is given to the fact that the attack started late, yet, if they were so dominant and the plan exceeded expatations in terms of enemy captured, territory seized, was there something military historians have pointed to as a major error?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/7fwyj9/operation_barbarossa_caused_massive_soviet/
|
{
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"dqf1wir"
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"text": [
"Logistics.\n\nThe campaign didn't start \"late\": the early summer months in Russia see significant rainfall, resulting in the so-called *rasputitsa*, literally \"time without roads\". Barbarossa's launch was timed so the ground could dry and the roads become usable again. In 1941 only 40,000 miles of the Soviet Union's 850,000 miles of road were hard-surfaced and suitable for use in all weathers. In the event, the roads were still atrociously bad. Most were little more than dirt tracks, which became rivers of glutinous mud after a summer downpour. These quickly became impassable quagmires to thousands of marching men, horses and vehicles. The roads were so bad that at one point it took the 7th Panzer Division two days to advance 90 kilometres. When they dried, they became rutted and treacherous, ready to turn an ankle or break an axle, and kicked up great clouds of dust that choked man, beast and machine alike: as well as being intolerable for men and horses, vehicles broke down at an alarming rate as filters were clogged and engines suffered dust contamination.\n\nIn such conditions, POL (Petrol, Oil, Lubricant) consumption accordingly rocketed: LVII Panzer Corps reported in August that its vehicles were consuming up to 30 litres of oil per 100 kilometres rather than the usual half-litre of oil. Even the few paved highways soon became unsuitable for large military movements because the ground they are built on was so poor: as early as two days into the campaign, XXXXVII Panzer Corps was delayed in crossing the Bug River because the surfaces of the approach roads were literally sinking into the sodden ground under such heavy weight of traffic.\n\nThen there were the Germans' vehicles themselves: there was a critical shortage of trucks. The deficit was somewhat made up by thousands of captured French Army and requisitioned civilian vehicles, but these were very rarely 4-wheel drive models and were quickly ridden to destruction on the horrendous roads. Where there were no motor vehicles, horses were used: an infantry division had an establishment strength of 942 motor vehicles compared to 1,200 horses, while the *Ostheer* invaded the Soviet Union with a total of 625,000 horses. A horse cart is unlikely to travel more than thirty kilometres a day and no more than five kilometres in an hour, to say nothing of horses' vulnerability: they are easily incapacitated by colic caused by poor feeding, infections picked up from contaminated water, or severe cold. Within a year of Barbarossa being launched, fully half of the *Ostheer's* horses had perished.\n\nThe perception gained from looking at maps that the *Ostheer* nearly took Moscow conceals the fact that the offensive had reached its culminating point around Smolensk: the German logistic system was incapable of sustaining an advance more than 500 kilometres from railheads. After this point, it would have to stop and redress its lines of communications before it could hope to make the next bound. It *tried* to do this, but Stalin was in no mood to give the Germans the luxury of a pause and hammered their positions at Smolensk with relentless counteroffensives. There was no opportunity to tidy up supply lines because those very same supply lines had to supply troops desperately trying to fend off the counteroffensive. There was no particular tactical flaw that doomed Barbarossa (though many German Generals subsequently tried to blame Hitler for focusing on Kiev and the Ukraine before taking Moscow); it was flawed from the beginning owing to the impossibility of sustaining it.\n\nSources:\n\nRobert Kirchubel, *Operation Barbarossa: The German Invasion of Soviet Russia*\n\nRobert Kirchubel, *Atlas of the Eastern Front*\n\nDavid Stahel, *Operation Barbarossa and Germany's Defeat in the East*"
]
}
|
[] |
[] |
[
[]
] |
|
ehg5rv
|
How much of an impact did the Civil War have on what is considered the Wild West?
|
You see things like Jesse James who was heavily influenced by the events of the war or the fact that the railroad became a vital point to the Unions success during the war and it's boom in later years.
How did it affect people going west or the general politics of the era?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/ehg5rv/how_much_of_an_impact_did_the_civil_war_have_on/
|
{
"a_id": [
"fck931j"
],
"score": [
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"text": [
"You're gonna have a hard time getting any kind of a comprehensive answer to this question, as it's just too broad of a topic. It would be like asking, \"what kind of an impact did World War II have on America in the second half of the 20th century?\" The question itself is so open-ended and complex that you could run in any number of directions trying to answer it. \n\nFor example, one could write at great length at how the role of women changed in American culture, specifically west of the Mississippi River, following the Civil War. One could go on for ages talking about the evolution of racial opinions and ideals out \"West\" following the Civil War, and how ideas of \"whiteness\" came into focus in a sort of mass hegemony that eventually eliminated notions of \"German,\" \"Dutch,\" or \"Italian\" in favor of just \"white.\" How do you define \"West,\" too? Is it by time period as well as region, and if so, what region and what time period? \n\nI don't mean to discourage discussion, but it might help to focus your question into something that's a bit more digestible. You mention how the war affected people going west, and \"the general politics of the era.\" What politics are you referring to? State or federal, and in relation to what?"
]
}
|
[] |
[] |
[
[]
] |
|
161gcn
|
I have a very specific question about the death of our star and supernovae (s?). Please look inside for details.
|
I was just watching a program where they were describing how a supernova happens. From what I've gathered when the metal compress and go up the periodic table and reach iron, fusion becomes impossible and the iron just absorbs energy from the star which kills the fusion process allowing it to collapse and implode in a supernova. Here is my question.
When our star goes red giant and absorbs the earth won't it absorb our iron core? Won't that stop the fusion and cause a supernova instead of a white dwarf? That's the part that I don't understand.
|
askscience
|
http://www.reddit.com/r/askscience/comments/161gcn/i_have_a_very_specific_question_about_the_death/
|
{
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"Without having many details at hand, and I'm sure someone can explain the fusion process better that I, Supernova are after all fusion has expired and caused by the mass of the red giant collapsing in on itself. this compression effectively blows the star apart (core-bounce) which is what a Type II Supernova is. so the earths core wouldn't make any difference to that process. However our Sun is just too small to become a Supernova anyway and it is destined to be a white dwarf. Only stars with sufficiently high mass become a full supernova.",
"It's not that suddenly adding iron to the star stops the fusion. What happens is that you cannot gain energy from fusing beyond iron. So at its core would be some iron and stuff that is no longer fusing, but the other elements, if they have sufficient pressure, can still be fused up along the chain toward iron. \n\nAnyway, our sun isn't large enough to supernova. It's going to expand into a red giant, give off much of its outer layer of gasses, and then have a dwarf remnant",
"As others have noted, iron doesn't kill a star, just like ashes aren't what cause a fire to go out.\n\nEven if it did, the sun already contains 0.16 % iron, or 53 Earth masses of iron. Another earth mass or 2 wouldn't be a very large difference."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
3okbjl
|
How common was circumcision among the Pre-Islamic Arabs? We can safely assume that Christian tribes, namely the Banu Hanifa and the Banu Taghlib , would have abhorred the practice, but what about the rest? What about the Quraysh?
|
[deleted]
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3okbjl/how_common_was_circumcision_among_the_preislamic/
|
{
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],
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5
],
"text": [
"Tangential question, why would assume those Christian tribes would abhor it?",
"Hello everyone, \n\nIn this thread, there have already been a large number of incorrect, speculative, or otherwise disallowed comments, and as such, they were removed by the mod-team. Please, before you attempt answer the question, keep in mind [our rules](_URL_0_) concerning in-depth and comprehensive responses. Answers that do not meet the standards we ask for will be removed. \n\nThank you!"
]
}
|
[] |
[] |
[
[],
[
"http://www.reddit.com/r/AskHistorians/wiki/rules"
]
] |
|
ej1pqc
|
Are animals attracted to each other’s faces the way humans are?
|
askscience
|
https://www.reddit.com/r/askscience/comments/ej1pqc/are_animals_attracted_to_each_others_faces_the/
|
{
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"fcxrtf0",
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"text": [
"Depends, i would assume some focus on colors, others on the rear-end etc... They haave specific evolutionary traits they look for.\n\nNot all humans look at faces either, or find different types of faces attractive",
"Oh sure, lots of species have been found to recognize and respond to faces and facial expressions. \n\n\nDomesticated dogs, for example, can read and respond to human facial expressions. Horses can do the same. That's different from responding to each other's faces, obviously, but they have that ability. \n\n\nPrimates (Chimps, gorillas, monkeys, etc) recognize and respond to faces, as far as recognizing other individuals by their faces, and recognizing moods and emotions based on facial expressions. \n\n\nWe know that sheep, of all things, can recognize one another by face, though I'm not sure about facial expressions specifically. \n\n\nI recently read an article about sun bears, which talked about how the bears appear to recognize and mimic each other's facial expressions much the same way primates do. \n\n\nI know there are other examples but that's all I can think of at the moment."
]
}
|
[] |
[] |
[
[],
[]
] |
||
15p9ji
|
If the earth's core cooled and solidified, would the planet get appreciably smaller? And if so, by how much?
|
askscience
|
http://www.reddit.com/r/askscience/comments/15p9ji/if_the_earths_core_cooled_and_solidified_would/
|
{
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"Related side question: How would the crust behave if the core and mantle solidified and shrunk? I imagine it would crack to try and lay evenly n the mantle but what exactly would happen?",
"Couldn't tell you exactly, but here's some estimates that are beyond rough. I'll have to make lots of assumptions.\n\nAssuming we don't talk about condensates and such, then all material changes density depending on temperature. So I have to assume that we're only talking about the liquid core changing just barely enough to solidify. Also have to assume that this is possible even under the heating effects of gravitational contraction.\n\nWe also have to assume that current ideas of earth composition are correct - so there is the solid core center which is not changing in our thought experiment here, but the liquid outer core is cooling.\n\nNext we have to assume that the liquid core is made of mostly iron, with about 4% nickel, and something else that lowers the density by about 10% by mass. So we can't do any calculations correctly unless we just assumed pure iron.\n\nNext we have to assume that we know the temperature of the liquid core, which we don't. So for this experiment let's assume the liquid core is just barely liquid and is almost turned solid.\n\nNext we have to assume that the compression of gravity and outer layers is not compressing the outer core significantly (or at least that the compression stays the same upon solidifying).\n\nNext we have to assume a mass for the outer core. I found calculations ranging from 1.603x10^24 kg to 1.928x10^24 kg. Let's assume an average of 1.765x10^24 kg.\n\nSo if the density of molten iron is 6.98g/cm^3 then the molten core would occupy 2.52865x10^20 m^3.\n\nAt this point you'll have to forgive me for getting lazy. I don't know the density of iron at it's freezing point, only at room temperature. So We can assume that whatever expansion or contraction that happens from the molten point to room temperature will be consistent and in one direction - either smaller or larger. So if the mass stays the same and the density of solid iron at room temperature is 7.874g/cm^3 then the volume of the now solidified core would be 2.24155x10^20 m^3. That's a difference of 2.871x10^19 m^3 or 2.871x10^10 km^3\n\nSo if we assume the current volume of the earth is 1.08321x10^12 km^3 then after the cooling the volume would be 1.0545x10^12 km^3. \n\nThe current radius of the earth is 6371 km. After cooling the new radius would be 6314 km.\n\nI think if the surface of the earth dropped 57 km we might notice it."
]
}
|
[] |
[] |
[
[],
[]
] |
||
j4jkn
|
can someone explain elasticity of demand and how it relates to the price of crude oil and other commodities?
|
Thx.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/j4jkn/can_someone_explain_elasticity_of_demand_and_how/
|
{
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"text": [
"I'll do my best, though I have a somewhat ameturish knowledgebase myself. Explaining it **like you're five**.\n\nLets say that you own a store. You want to have customers, so you set nice and low prices. It works and people come and buy your stuff. This is great but you need to make some money. \n\nYou want to find out: If you raise the price by a little bit, will your customers still want to buy it? So you do some asking around.\n\nFor some things, like bottled water, people are OK with paying a little more.\n\nOn paper clips, people are totally against it and won't buy from you.\n\nTo wrap up the analogy, the demand for the bottled water would be \"inelastic,\" because people still wanted it after the price went up.\n\nThe demand for paper clips would be \"elastic\" because people weren't as willing to pay the higher price.\n\nWe use those terms because if someone wants something less because the price is higher, they're flexible. Elastic. They want it, but not *that* bad. And vice versa.",
"People don't want to buy things if they cost too much. Some things, though, are so important that they'll buy them even if the price goes up.\n\nPeople probably won't pay a million dollars to buy milk, but they'll probably pay five dollars because everyone needs milk and most people have five dollars.\n\nAnd we like to go to the movies, but we probably won't go to see The Smurfs if movie tickets cost a hundred dollars each. \n\nBut everyone needs gas for their car s, and that's why they'll pay eighty dollars to gas up their car even though that's a lot of money for gas. And that's why daddy always says bad words when we go to the gas station."
]
}
|
[] |
[] |
[
[],
[]
] |
|
2hcwnb
|
White reflects, black absorbs. White radiates little, black radiates a lot. What do transparent materials typically do?
|
If I had a perfectly insulated box with a transparent lid, containing a a vacuum and an object at the bottom, would the object at the bottom get colder than ambient air temperatures at night, if the sky is clear?
For the purposes of this question, assume transparent to all frequencies in the elecromagnetic spectrum, white to all frequencies, black to all frequencies.
|
askscience
|
http://www.reddit.com/r/askscience/comments/2hcwnb/white_reflects_black_absorbs_white_radiates/
|
{
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"ckrl7iw"
],
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"text": [
"Transparent materials let most of the light pass through. Also, many \"transparent\" objects are opaque to other wavelengths of light. Something that lets visible light through might for instance block radio waves or vice versa. \n\nAlso, white *reflects* visible light through diffuse scattering. Black absorbs visible light. How such objects irradiate is a separate concern and a function of temperature and their emissivity."
]
}
|
[] |
[] |
[
[]
] |
|
9v9rgx
|
Do other mammals (or animals in general) "lose their voice" like we do?
|
askscience
|
https://www.reddit.com/r/askscience/comments/9v9rgx/do_other_mammals_or_animals_in_general_lose_their/
|
{
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"**Disclaimer**: I wrote more than I meant to. If you don't want to read it all, the most important parts are the first and last paragraphs.\n\n & #x200B;\n\nYes.... and no. The sounds made by all animals with lungs are made through vibrations in the larynx a.k.a. \"voice box\". In short, we (and other mammals) force air through our larynx while opening, closing, and vibrating it. Different shaped trachea, larynxes, and mouths result in the multitude of sounds created in the animal kingdom.\n\nWhen we lose our voice it is usually because of a common cold, viral infection, or overuse of our voice box that results in swelling and irritation, in turn, inhibiting the use of our voice.\n\nSince \"losing our voice\" is simply a result of interference with our larynxes, and every mammal as far as I'm aware of has a larynx; it is safe to assume that many animals can lose their voices.\n\nThe reason I said no at the beginning is because of this article.\n\n[_URL_0_](_URL_0_)\n\nIt basically says that cats and dogs can lose their voices but while it is nothing to worry about when humans lose their voices, it can be very dangerous with some animals including cats and dogs. This is because it is much more common to lose their voice due to major things like trauma, cancer, paralysis, and sever infections.\n\nIn summary, many animals can lose their voice but many lose their voice for different reasons than humans do which is why we don't see it very often."
]
}
|
[] |
[] |
[
[
"https://www.petmd.com/blogs/thedailyvet/ken-tudor/2015/february/voice-changes-pets-more-serious-you-think-32462"
]
] |
||
43ftr1
|
why did chairman mao kill so many people including teachers? what could he have been trying to accomplish?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/43ftr1/eli5_why_did_chairman_mao_kill_so_many_people/
|
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"There are two moments in which post-war China suffered mass loss of life.\n\n1)\tThe Great Leap Forward (GLF)\n2)\tThe Great Proletarian Cultural Revolution (GPCR)\n\nYour question presupposes that Mao personally killed people in the GLF and GPCR, or at least that their death was his intention. Any serious understanding of the Chinese revolution and the post war years up to Mao’s death highlights how silly this idea would be. Mao was a member of a massive and developed political apparatus (the CCP), which held divergent views and contained harsh political disputes and infighting. To place blame for the deaths solely him is increasingly dubious the more you read about the history of China. We can highlight his role as a source of policy and as the ‘great helmsmen’, and in this way we can morally and historically hold him accountable to an extent, but to say that it was intention to kill millions of people, which is presupposed in your question, that’s absurd. \n\nIt’s interesting that so many bad historians prefer to extrapolate on the psychology of Mao, something I admit we can know a little bit about, but is often largely not the thing we should look at if we want to understand historical events, particularly the GLF and GPCR. The notion of intention relies on a psychological reading of Mao, and it is from there that the ludicrous equation of Mao with Hitler (“even worse!”) is made. It is important that these psychological portraits (“Mao was a monster!”) are generally made without historical or political analysis of Mao or the CCP. Often, they are done with a common-sensical invocation stylized in the manner of a dull monologue by a Dad on the holidays.\n\nYou can read about this on your own. I would suggest Meisner’s “Mao’s China and After”, which I will derive much of the information below from. It is a great primer on the Chinese revolution and done in a critical way that attempts to hold Mao up to his own principles.\n\nAnother one to look up is, “Was Mao Really a Monster?”, the later which attacks the lack of credible source material used by bad historians when writing about Mao. \n\nFinally, I cannot recommend enough the book, William Hinton’s “Fanshen” which highlights the land reform and revolutionary process in a small village in China, as observed by the author. It will give you the emotional depth necessary to truly appreciate how important Mao and the communists were in transforming Chinese society. It truly was a liberation from a two thousand year hell.\n\nThe majority of post war deaths in China occurred in the GLF. In order to understand the GLF, I’ll give background on why the project happened in the first place.\n\nBefore that,however, briefly on the GPCR. This was a dynamic and complex process involving many political actors, both on the right and the left. The majority of deaths that occurred were leftist revolutionary elements being killed by rightist military elements. Mao and his call to eradicate the bourgeoisie that had inhabited in the party took a form well outside his, or his wife’s, control. The people on the ground were relatively autonomous from Beijing, even going farther then Mao (see the Shanghai Commune). It’s a historically amazing period of time and I suggest further reading about it. It also ended in failure, which is why China is so capitalist today. \n\nThe GLF had its basis in the First Five Year Plan which was initiated from 1953-1957. This saw much success as defined by its goal, but the plan was based largely on the Russian Soviet method of development, which aimed at growing capital-intensive industry and urban centers. 88% of capital was invested in heavy industry, and industrial workers grew from 6 to 10 million. This was at the cost of rural agricultural areas, whose labor was the basis for the investment in heavy industry. Peasants had to sell grain to the state at fixed prices and were given heavy quotas to meet.\n\nNot only did this exacerbate differences between urban and rural, but the First FYP created the basis for the growth of a bureaucratic class of specialist technicians, and accompany party apparatuses. Just like the Soviet path of development to ‘socialism’, a new class basis was made while exacerbating differences between rural and urban areas. The idea here is the create the basis of communism through developing productivity, infrastructure, industry, etc. These create the \"material conditions\" to then reorganize society for communism. This idea is called \"stagism\" or \"developmentalism\" and was never propounded by Marx, only conservative interpreters of him. It should be said that \"stagist\" thinkers are usually anti-revolution. \n\nThe First FYP established a new social hierarchy and replaced the old ideal of a spartan communist guerrilla with that of the technical specialist.\n\nIn order to increase agricultural production the CCP formed mutual aid teams to increase production. Mao, believing that as a result of the First FYP, capitalism was developing in the rural and urban areas, used the mutual aid teams to combat those forces. He called for establishing agricultural collectives, believing this would also increase grain production. These collectives went from 100,000 to 600,000 by June 1955. Other cadre in the party, who disagreed with Mao’s ideas put a halt to this. Internal fighting ensued, Mao was blocked. So he gave a speech outside official channels calling for full socialist agricultural cooperative by 1960. He said that the party was conservative and the masses needed to lead the way. \n\nThe people responded in kind and the politburo followed suite, sending organizers to facilitate the movement for collectives. By the end of 1955, 63% of families were in cooperatives. Full socialist collectivization happened by the summer of 1956, largely without violence. \n\nThis already is in contrast to Stalin who accomplished \"collectivization\" in the 1930’s with much violence and suppression. It is necessary to highlight this difference because Mao focused on using the “mass line” and aimed at a different path of development from Stalin. The two are not equivalent in methods or politics. \n\nHowever, bear in mind this process of collectivization happened within basically a year. \n\nIt was also during this time though that China had what was called the 100 Flowers campaign. Basically Mao said the intelligentsia could criticize the party. They did. The politburo was against it. Mao said it should be accepted. There was back and forth of repression on the intelligentsia that did speak up, and much of their criticism was that the CCP had abandoned Marxism and revolution. Tragically Mao later led the charge against the “rightists” then repeated what they themselves said years later in his criticism of the CCP. I bring this up because the 100 Flowers campaign highlighted even more political disagreement (class conflict) in the party. Those who were against it from the outset (Deng Xiaopeng and others) were proponents of the Soviet method of development and stood to gain the most from the continued growth of the bureaucracy.\n",
"The Cultural Revolution was primarily about Mao's quest for ideological purity in the Communist Party. Anyone opposed to Communism or Maoist thought became a bourgeois element working against the interests of the people, and therefore they had to be eliminated. Mao blamed teachers and professors as \"revisionists\" corrupting the minds of students against proletariat interests. \n\nThere was also the fact that Mao wanted the total destruction of traditional Chinese culture because to him traditions and religions maintained social barriers, and traditional Chinese culture frowns on the youth criticizing their parents and elders. So he encouraged students to murder their teachers as a subversion of that.",
"He was trying to purge China of The Four Olds as these were seen to only further the exploitation of the classes. The Four Olds are old customs, old habits, old culture, and old ideas. \n\nA lot of teachers were executed publicly, monks were humiliated in the streets, a great number of Kung Fu masters took to the hills or left China altogether. These were all seen as part of the Old China that the Cultural Revolution was meant to be burning off. ",
"Good to remember that a lot of these killings were personal vendettas. For example, you might want to hurt a teacher who had just failed you, or a landlord to whom you owe rent. \n\nIf anyone is interested in this period, I recommend this book.\n\n_URL_0_",
"Well for example during the amenian genocide the turks specifically targeted intelligent people/high standing officals. This included Politians, Merchants, Teachers, Anyone with an Education(by that i mean university), so on and so forth. Now you ask why is that important and why would you round up those people first? Simple. You silence the people most likely to speak up, organize a crowd and get the hell out of dodge. Secondly. These people are the ones who carry the history of the culture, the land, the ancestors, and the stories of your people. Standard procedure, if you kill them you are wiping out the culture that these people had. What makes you italian, french, german or whatever is the culture, song, dance, and history you kill off the people who have this knowledge you kill off the culture. Mao was trying to kill off the old ways, cultrure, tradition(more like customs is what im saying). So that he could usher in a new china with new customs and new ways of doing things. Any questions just ask",
"Control\n\nyou have to look at china before the Japanese took over, warlords split the country into a hundred fiefdoms, the communists managed to unite the country in the chaos of the Japanese invasion but that doesn't mean their grip on power was secure, from 1950 onwards there was wave and wave of crackdowns on counter-revolutionary's of one sort of another, really it was about destroying other centers of powers in china, he was consolidating control and authority in the communist party. Teachers were just one of a long line of potential threats that were attacked, starting with legitimate and ending with paranoid \n\nIt's a pretty similar pattern that most dictators go through. ",
"The Cultural Revolution (I assume that is what you're referring to) was largely Mao's attempt to continue fighting \"reactionaries\" after that war was long over.\n\nIt wasn't crazy to think that cultural ideas propagate certain values about the world. Confucianism, reverence for authority/elders, are not value-neutral. Mao saw this as a threat.\n\nThe problem obviously was that the war had already been won. The Chinese Civil War ended in 1949 with the Nationalists fleeing to Formosa/Taiwan. The Nationalists hadn't left behind a compelling vision for the future, and they were comprehensively beaten militarily. The people who were left in China as \"enemies\" were... people who held little power anymore. People who were born to the wrong families. People with the wrong ideas.\n\nSo Mao had made his name fighting a very protracted civil war (1927-1949!) and he found himself suddenly the most powerful individual in the Chinese Communist Party. As best I can tell he never stopped feeling besieged by enemies--he devolved into paranoia which became increasingly horrifying as his personal power increased. There were no real enemies left to fight, but Mao saw shadows everywhere.\n\nMao still had massive personal popularity, however, and he inspired many of the younger generation. He called upon them to rise up. They became his Red Guards, vanguards in a battle against the last of the old guard--teachers, Kung fu instructors, people from once-wealthy families. Mao had led China to a new Communist future and he was terrified of losing it.\n\ntl,dr; Mao was never able to understand the war was won, was very popular personally, and gave younger people who had missed the glorious revolution a chance to get involved, which many of them enthusiastically took\n\nRecommended reading:\n\nNien Chang, Life and Death in Shanghai (autobio)\n**Roderick Macfarquhar, Mao's Last Revolution** (broad overview, very dense)\n",
"He was evil scum, and killed anyone who wasn't a \"Communist\". Stalin pretty much did the same thing. When you slaughter millions of people you have everyone living in panic and fear, and that's the \"Communist\" way to control people. The interesting thing to realize is that none of those countries ever had anything similar to real Communism. They always used the guise of Communism to enact pure Totalitarianism.",
"Well, Mao didn't directly order killing of the teachers, since the Cultural Revolution was in large part carried out by the Red Guards, which are basically middle school and high school kids basically given power to destroy whatever or whomever they feel like is \"Counter-revolutionary\", which basically become whatever they don't like. It's not hard to imagine why these teenagers, suddenly in a position of power, would do to people who once had power over them and they feel as wronged them, and for a lot of the students their former teachers became their natural targets.\n\nThe Cultural Revolution itself was never actually about destruction of the old culture or ideology as it was proclaimed, it is mostly a front for power struggle since Mao is becoming paranoid and felt that he was losing power, so he can remove anyone in his way just by deeming them \"Counter Revolutionaries\".\n\n\n",
"Because when you value ideology over everything else, that is the inevitable result. I do not say this flippantly- it is simply that that is the answer. History is rife with examples.\n\nSource: spent childhood in southeast asia/china in the 70's/early 80's, saw the cultural devastation firsthand.",
"\"He who controls the past controls the future; he who controls the present controls the past.\" \n\nPretty much what George Orwell had warned that modern totalitarian states would attempt to do. Culture, teachers, historians and monks could all remember what it was like before the revolution and as such they had a means of comparing the old with the new and judging which was better. Naturally this is a danger to a ruling government which portrays itself as being superior to the China of old. If Mao could kill off all the people who could remember things being different, or at least the people who were likely to talk about the old times, then he could say whatever he wanted about the past to justify the present and nobody would be able to contradict him. ",
"I think Orwell explained it better than anyone else:\n\n > Power is not a means; it is an end. One does not establish a dictatorship in order to safeguard a revolution; one makes the revolution in order to establish the dictatorship. The object of persecution is persecution. The object of torture is torture. The object of power is power.\n\nChairman Mao killed so many especially teachers to perpetuate his own power.",
"Like many totalitarian dictators, Mao sought to create an absolute break with the past so that he could impose his own personal ideology on to his nation in its place. As a militant revolutionary, violence was not only seen as a legitimate means to this break, but as the preferred means. \n\nThe result was an escalating spiral of purges (i.e., murders) of anyone who had any level of investment in or knowledge of the previous system - not just businesspeople and aristocrats, but professionals, artists, academics, even doctors.\n\nIt's a well-known phenomenon that also occurred later in Khmer Rouge Cambodia, earlier in Stalin's Soviet Union, and a couple of centuries before during the Jacobin Terror in Revolutionary France.",
"While a lot of people are talking about the \"Culture Revolution,\" where Mao got the young people into anti-traditionalist mindset, the vast majority of the people who died came from his second five year plan.\n\nFive year plans had been the Stalinist method of industrializing the economy. The first Chinese Five Year Plan was fairly successful, as far as central planned communist economic polices were concerned. Mao decided to followup the success with the [Great Leap Forward](_URL_0_).\n\nIt was horrific disaster. Mao wanted to surpass the UK and the US in industrial and agricultural output. For industry, tens of millions of people were brought from the country side into cities to work in state owned factories. Material shortages were a constant struggle, and these people required a large amount of food to eat. \n\nTo solve some of the material shortages, Mao decided to pull farmers away from their fields to build up steel furnaces in their backyards. These poorly constructed mud furnaces had a tendency to just *explode*, and the farmers who were not killed by their own furnaces only produced essentially unusable steel.\n\nDiverting labor away from agriculture and towards industry, combined with harmful irrigation projects, agriculture experimentation, and continued exportation of grain even in the face of shortages led to *massive* famine.",
"artists and intellectuals are always the first to go in a totalatarian state. Teachers are definately included in the intellectuals categories because they have the ability to point out the oppression of the state to the larger population. plus they technically aren't necessary for a productive society like farmers/engineers/plumbers etc etc. They really only represent a threat to the state.",
"When one wants to bring about a new worldview and culture, one must consider what to do about the reactionary elements. It's very easy to see the reactionary people as a physical embodiment of the old ideas; therefore in a feat of backward logic one might try to simply eliminate the physical embodiment of the old ideas: teachers, religious figures, old aristocratic families et al. It hasn't worked so far, people persist in their path, and are loath to consider, they are wrong, and love the notion of a quick direct solution. ",
"It's extremely rare that there's an ELI5 that I can answer, so this is an exciting day for me.\n\nAs mentioned elsewhere in this thread, Mao was trying to purge China of the \"The Four Olds.\" The reason he was doing this was to create a sense of permanent revolution (spoiler: it didn't work). A worker who made the most widgets would be made foremen, professors were stripped of their position and beaten by students, etc. The idea was to create a sense that the little guy was getting his chance and, under Mao, he would be prosperous and prestigious.\n\nIt created a socio-economic mess that China is still dealing with to this day. ",
"Mao Zedong was not entirely the accomplished intellectual. Yes he studied in a school in Changsha and married the daughter of the principal. He may have read the few Marxist treatises translated into Chinese. \n\nHe mastered the traditional Confucian essay, but his style was very basic and his Hunanese accent was execrable. The intellectual ferment however was in Beijing and he went there and tried to get into Beijing University. But he failed and took a job on campus as a cloakroom attendant. He tried to talk to some of the great Marxist intellectuals but they rebuffed him and mocked his rough peasant manner. They refused to allow him to attend their lectures. \n\nMao never forgave them. At the Whampoa Military School in Guangzhou in the early twenties, Mao taught a course in peasant activism. Chiang Kaishek and Zhou Enlai were the senior academics. Mao had never studied in France or Moscow like Zhou and other leaders, who had the support of Lenin and Stalin. Both of whom looked down on Mao as an illiterate peasant revolutionary. \n\nIt wasn't until the defeat of the CCP in Shanghai and Jiangxi that Mao's bullish insistence that only a peasant army, which avoided the cities could prevail in China. Once in Yenan, where the Red Army was joined by many intellectuals, Mao carried out a thorough rectification of intellectuals (Yenan Forum 1942) which set their limits and brought them under control. \n\nAgain after the Founding of the People's Republc, Mao had a big battle with the overseas educated intellectuals, who backed by Stalin, urged that China build itself up after a decade of war, using so-called New Economic Policy of encouraging a class of \"patriotic capitalists\" to build up new business and expand throughout China. Mao insisted that only by following Stalin's method of complete collectivization of agriculture and nationalization of industry would China prosper, indeed become greater than the Soviet Union. \n\nHence Mao's reaction to the Hundred Flowers was visceral and the Cultural Revolution began as a literary criticism campaign against selected writers who had written critically of certain leaders, implicitly Mao. During this campaign all intellectuals were denounced as the \"stinking ninth category\" 臭老九 of anti-party, anti-revolutionary elements.",
"Killing teachers is a famous tactic in any violent revolution. Along with teachers, common targets include religious buildings/shrines/etc, libraries, and schools. The general idea is to purge any ideas that conflict with the new regime/government. I believe that this tactic may even be mentioned in the Communist Manifesto, if I recall. Anyhoo, this is the big reason why we dont have many documents from the old world from any culture. Its not that \"The Republic\" survived because it just happened to be one of the classical texts to survive wear and tear, its that when Greece was destroyed, everything was burned, and \"The Republic\" -being a rather popular text at the time -had copies around the world which were able to escape the flames. Likewise, teachers, religious leaders, and scholars are all bases of knowledge, and so get the proverbial shaft when violent revolutions displace power abruptly.",
"Killing the educated/intellectuals is a standard for totalitarian regimes. Beware if you have calluses on the sides of the fingers or have eye glasses. Shows you can read and write. The uneducated are far easier to manipulate. Redditors are doomed.",
"From a practical perspective, destroying education is an excellent way to preserve power. An uneducated populace is unable to produce a critical mass of people who evaluate existing problems and see that there is a better way that doesn't involve those in power. Instead, they resign themselves to the status quo as inevitable or even celebrate it as good. \n\nNow consider: am I talking about China or the US?",
"Would it be right to say that china was in such a desperate state because of it's history with britain and the opium wars? ",
"Accomplish? He was a genocidal maniac. He put some other goal above saving human lives.",
"_URL_0_\n\nCrash Course World History gives a nice overview. Thank you John Green.",
"The first thing you want to do when you go full dictatorship, is to cut free the academics. Kick them out of the country, kill them, otherwise get rid of them, but they are the BIGGEST threat after a military coup, because they'll rally the people.\n\nIf the academics get to the people before you can demoralize them, you tend to have problems.",
"Teacher killing was one of the consequences where Mao mobilized students to form his army of red guards with the intention to eliminate \"class struggle\" and \"counter-revolutionaries\". However, his real intention was to maintain and reinstall his influence, using the red guards and Lin Biao(his right hand man and a general of People's Liberation Army), in the CCP since he'd lost a lot of power after the failure of his Great Leap Forward and the growing control of Liu Shaoqi(his appointed successor). In order to reinstall influence, him and Lin Biao created and spread propaganda claiming there are a certain percentage of chinese citizens that are traditionists(右派分子) who are supposedly counter-revolutionaries that should be punished. This idea lead to wide spread chaos and a form of witch hunt where intellectuals(including teachers and his political enemies) were to be publically shamed and executed by the red guards. This essentially is the cultural revolution. \n\nEdit: grammar",
"Mao launched the Cultural Revolution recently after his monumental failure of the Great Leap Forward, in which he became the laughing stock of the Chinese People and was almost ousted from the Chinese Communist Party. (In fact he resigned as State Chairman in 1959.) He did, in fact, have many enemies in the Party after that incident. Mao was not some leader that the people of China blindly followed, contrary to wherever the hell that belief came from.\n\nThe Cultural Revolution was not actually some \"idealogical purge,\" and the people who think so fell for his trick! It was Mao's thinly veiled attempt at silencing dissenters. I am surprised that so many of us, here in the Western world, have fallen for Mao's false guise, even 4 decades after it ended.\n\nLike I said earlier, after the failure of the Great Leap, Mao had close to no backing in the Chinese Communist Party. However, he was still quite popular **among the people who were not aware that many of China's ailments were his fault.** Many Chinese educated intellectuals by the 60s and 70s knew how a lot of the troubles China was facing at the time were due to this dude's missteps. The people who still had faith in him were, (not to sound discriminatory or anything, but it's the unfortunate truth), the mostly uneducated people whose only source of information was the propaganda being fed to them. And so, he came up with an excuse as to why the dissenting classes needed to be shut up, and he acted upon it. He also then used this same excuse to pick off any dissent in the Party as well, and regain authority over it.\n\nAlso, not to downplay how stupid of an idea the entire thing was or anything, but it was not as brutal and cruel as it's made out to be in the West. We sure like our dramatic history here, don't we! Sure, there were executions and beatings and stuff, but not en masse. The only people facing that were the very vocal dissenters of Mao or the Cultural Revolution, those who spoke out. Now, I'm not saying that's a good thing, but it was not some class genocide or anything. Most of the intellectuals and \"bourgeoisie\" were told(forced) to, pretty much, go to the countryside and shut up for a couple years; \"go pretend like you're learning to be farmers or something!\" My parents grew up in Cultural Revolution China, and both also participated in the 1989 Tiananmen Square protests. (Neither of them were there on June 4, \"tank day,\" but my father's little brother, my uncle, was.) They come from both sides of the Revolution, my mother's family being college educated intellectuals who were relocated to the countryside, and my father's family one who had already been robbed poor during the 1949 revolution. My mother's family was not beaten, harassed, or anything. They were given land and servants to tend the farms, told to move out to the countryside, and pretend like they were learning the ways of the proletariat for a couple years. Shush up and you'll be safe!",
"Mao is a very clever man. Unlike Stalin who signed death lists with his own hands and literally ordered thousands to death. Mao took the much more \"managerial\" route. He created a situation where the people are free to do what they please. Mao gave people an excuse to unload all of their private hatreds towards each other. That excuse is the \"4 olds\" (_URL_4_). Basically, Mao said, \"there are anti revolutionary in our midst. People need to be vigilant.\" The people replied by going on witch hunts over everyone and anyone. If you remember the mock court in the latest Batman movie, China basically had many such mock courts during the culture revolution, headed by zealots that loyal to Mao's ideology (for example, the Red Guard, group of self proclaimed enforcer of Mao's teachings), and such courts persecuted anyone and everyone. So it was not... technically... Mao or the Communist government that caused the death of thousands, but the people themselves did it to themselves. Unless you see a photo of that period happened in a official court room. All other trial photos from that period are all those mock courts set up by whoever the mob leader is.\n\nFunny and the sad thing is, many local law enforcement or officials tried to stop the mock courts, but they were branded traitors and anti revolutionaries and themselves were thrown into the mock courts. Because Chairman Mao said \"people be vigilant\" how dare you go against his will? Not all Chinese government officials are corrupt or spineless, then and now. Look at this poster from Culture Revolution - _URL_5_ - the people walking proud holding up Chairman Mao's Quotations, doing Chairman Mao's will. Basically, if you say what you are doing is for the revolution and for Chairman Mao, you have a free pass to anything. No one dares to stop you, to do so is treason. Needless to say, many took advantage of this situation and used the opportunity for their own selfish interests (This is source of vast majority, if almost all, of the travesties happened in the Culture Revolution. Read about the Red Guards, their origin, to understand the lawless chaos at that time below).\n\n(A side note on the Red Guard (_URL_0_ - Note the quote at start of the wiki \"Chairman Mao has defined our future as an armed revolutionary youth organization\" and armed they were. The red guards executed many people during the mock treason trials on their own accord. They were that fanatical). They employed similar tactic to SJWs. SJWs say \"if you don't side with us you are a bigot, racist, etc\" Red guard say \"if you don't side with us you are anti revolutionary.\" Red Guards, at height of the culture revolution have picket lines at road intersections, when people stop waiting for lights to turn green. Red Guard would come to them and say, \"recite line XXX from Mao's Quotes - a little red book recording many of Mao's writings and conversations (_URL_1_ - If you read the Mao's quotes. You'd understand Mao's brilliance. The Chinese calls that part of Mao's quality, the \"quality of emperorship\". That's partly why the Chinese supported Mao). If you cannot recite the line, you are made to stand there, read the book till you memorize all of it.)\n\nThe desired effect from this chaos is purging of those who are not completely loyal to Mao. Because only those who are loyal to Mao's ideology can survive such mock courts. Basically, like a cult, at the end only the fanatics stay. This is a brilliant move, because what Mao did is simply unleash the mob. Give the mob a get out of jail free card, even better, a do what you want card.\n\nOf course the ultimate goal of the purging is to cement Mao's own power. Mao wanted, like Kim in North Korea, make China into another dynastic succession monarchy with him and his sons at the helm. Unfortunately, and fortunately, Mao's only none intellectually challenged son died due to American bombing in the Korea War (_URL_2_ - The wiki and China officially says they were cooking at night that's why they got spotted by American bomber, but at least in Chinese folk history Mao's son went out for a smoke and that did him in, smoking is indeed bad for your health. Mao blamed Peng DeHuai, his son's direct superior, for his son's death and eventually found an excuse to kill him by directing the mob his way. Peng Dehuai is a great general worthy of his own reddit post really). Chinese people actually pretty thankful to America killing Mao's only worthy son (kind of ironic really). If US did not kill Mao's son. China right now would be a ICBM nuclear fusion bomb capable hermit giant kingdom *(China developed Hydrogen Fusion bomb in 1967, during the culture revolution - _URL_3_)* 100000 times worse than Korea.\n\nBut the whole thing did have a positive side. Many ancient Chinese shackles did get broken. For example, equality between the sexes, at least in cities, are pretty much achieved through Culture revolution (you think aborting female fetus now is bad, imagine what it was like before culture revolution). Women were deemed necessary member of the revolution and received equal opportunity in education, work, and advancement. It also broke many old customs that bind people to their land and therefore their socio economic status. It re-unified public opinion and created a China more united than ever before. It also ensured the absolute loyalty of the Army and Executive branch, therefore ensuring stability. It destroyed the traditional confucious ideals and religiosity and making people more pragmatic and materialistic (in a mere decade China became atheist - the Chinese now are superstitious but not religious - who else other than Chairman Mao can achieve such a transformation), putting foundation for Deng Xiaoping's economic reform decade later.\n\nDown side to getting rid of the shackles of the past is that many good customs also got lost, but fortunately they are preserved in Taiwan (another thing the Chinese thank America for, which is also ironic).\n\nEdit: About Mao's son, Mao An Ying's death, weeks passed till someone finally dared to report the death of his son in Korea to Mao. After hearing the news, from his secretary's memoir, Mao lit a cigarette, inhaled and pondered for a long while, then said, \"It is war. Casualty is expected.\" (You have to imagine Mao says this in his strong southern Chinese dialect, strongly suggest you google Mao speak) But later on, Mao showed some emotion and said, \" By Chinese tradition, only son counts as your legacy, girls don't. One son's killed (referring to Mao An Ying) and the other lost his mind. Looks like I have no legacy left.\" Quite sad really. At that moment, Mao realized his dream of creating an empire died with his only worthy son.",
"The Great Leap Forward caused the largest famine in recorded history. Yes, the cultural revolution was up there with the public killings but its death numbers dwarf in comparison to the results of his economic policies, which number lies in the 10s of millions.",
"Taking an alternate angle from many people here (although many of their explanations are correct), Marx's philosophy sort of called for it. \n\nYou know how when Moses and the Israelites crossed the desert (pretend for this analogy it was a real thing that actually happened), many of them wanted to turn back? There was no clear path ahead and their journey had been terrible up to that point. To Marx, those would be the doubters who had to be eliminated before you could complete the journey, because they'd always keep telling everyone that things were better before.\n\nAnother way to put it is that capitalism relies on humans being greedy by nature. In the philosophy of communism, humans are only greedy by nurture (we're raised/developed to be that way) and it's possible to nurture a generation that isn't greedy. But in order to do that, you need to wipe the slate clean of that older generation.\n\nNow there's definitely some debate over whether Marx meant it literally or not, but that is the logical end of his sentiment. \n\nMao and Stalin were murderous assholes, but it's arguably a necessity in Marxism. A lot of people point out that they had totalitarian governments and not communist governments, but the point of this is that (I believe) Marx thought you need to travel through totalitarianism in order to get to communism.",
"It's difficult to make any real sense of why Mao Zedong would do such a thing until you accept that he was a megalomaniac much like Joseph Stalin and a bit like Hitler. People like Mao who believe they have been chosen to change the world also believe that anything that stands in their way, including teachers, must be destroyed. Under normal circumstances such criminal behavior -- after all, they sanctioned torture and murder -- would result in severe penalties, jail, even the death penalty. But since they make the rules . . . . \n\nMao's goal was to \"start over\" so not so different from Cambodia's Khmer Rouge who sought to wipe out the past and begin again. That's a bit like ending gravity. You can't do that. Any political movement that is based on mass murder is seriously deformed. Mao was a mass murderer and a thug. He should have been arrested or killed by someone brave enough. Unfortunately, no Chinese was. That he's still revered in China is utterly pathetic. Imagine if Germany still hung banners with Hitler's picture on them? ",
"Stupid people make best worshippers. You don't have to look too far to see it all around you.",
"Like most leftist, progressive ideology, Mao wanted constant \"revolution\" and \"change\".\n\nThis is the best tool for consolidating and maintaining power.\n\nIt requires constant conflict and identifying of a new enemy and victims at different intervals to keep the authoritative apparatus from ever falling under the eye of the people.\n\nSame story over and over.\n\nEvery country that's embraced communism and state economic planning eventually becomes an autocratic murder factory.",
"Mao Zedong didn't actually kill anyone. Mao was a self-centered maniacal sociopath who sat by a swimming pool all day long, slept and ate whatever and whenever he wanted, bedded an endless string of young women and thought his personal philosophies were the governing policy of China. What killed people was the amazing ability this lazy monster had to get people to do what he wanted.\n\n",
"Mao had certain ideological tenets he wanted everyone to adhere to and believe in. Those who argued against them were a threat to the spread of the ideas he wanted to proliferate. However, a lot of the people whose deaths he was responsible for weren't intentional killings. Nobody knows the exact number, but upwards of 40 million Chinese people died as a result of collectivized communities during what is called the \"Great Leap Forward.\" The vast majority of those deaths were a result of starvation.",
"Mao was put out of politics by Deng Xiaoping and Liu Shiaoqi. Mao wasnt very pleased with this and was concerned that the leadership wasn't going to continue the revolution. Mao took a gamble and unleashed the cultural revolution in China to put himself back in the center of politics; the primary instrument this was accomplished was through the Red Guards. The Red Guards acted a lot on their own and used the little red book as their guide to conducting the cultural revolution. They ended up committing a lot of violence. \n\nI say he took a gamble because what Mao unleashed was a fervor across the country to eliminate incorrect political thought; it could have easily backfired against him in that other people could have rose to power against him at that time. ",
"This is a topic I have done a lot of reading about - here's my best summarized explanation of why it happened and why so many teachers were targeted (but it's still rather long):\n\nThe Cultural Revolution was a response by communist students who thought that the Chinese Communist Party (CCP) of the 1960s was becoming corrupted by careerism, authoritarianism and self-serving bureaucracy, creating a new class system where inner-party members (mostly academics, politicians and bureaucrats) formed a privileged elite oppressing the peasants and workers just like in the days before the revolution. There was a precedent of this happening a few decades earlier in the USSR under Stalin. Seeing as the entire point of communism is to abolish class systems and (ultimately) the state entirely, those who believed most passionately in the promise of communism (mostly students) were prepared to fight against this trend.\n\nMao saw the same trend and was alarmed by it, but he was old and knew he would die soon and couldn't do much to stop it on his own. He made speeches and pronouncements urging the young people of China to defend against this creeping authoritarianism, consolidation of power in the central state (rather than being diffused in local democratic communes as had been encouraged by earlier policies) and the \"Capitalist Road\". The Capitalist Road was the name given to the tendency within the bureaucracy to introduce capitalist elements back into the economic model and winding back of the gains of the workers and peasants made by past class struggle e.g. the Iron Rice Bowl which granted certain necessities of life (such as sufficient food, water, education, healthcare, etc) as basic human rights, regardless of circumstances.\n\nThe academics and teachers who were targeted by the the cultural revolution were mostly intellectuals at China's top schools and universities for the most outstanding students, and traditional Chinese culture has a strong norm of deference towards teachers, so (even though in the west we rarely think of teachers and academics as the elites or the ruling class) they often occupied positions of unusual privilege and (like the top bureaucrats and politicians) as time went on they began to enjoy more and more luxuries not available to the common people. Unsurprisingly, many academics started to promote ideas that would further benefit them and increase the difference in living standards between this emerging upper-class and the general population (e.g. capitalism.) It's not hard to see why their students came to the conclusion that they were corrupted and included them among those that needed to be purged from power.\n\nThe students marched academics, politicians and bureaucrats out to fields to do manual labour, burned down official Communist Party offices of branches who were implementing Capitalist Road policies and killed (or pressured local justices into executing) party members, teachers and officials who were particularly flagrant in exploiting their positions for personal gain. The reasoning was that those who were redeemable could be best shown the error of their ways by destroying their positions of comfort and giving them 1st-hand experience of the living conditions of the average citizen to remind them how the people lived and who they were supposed to be serving. \n\nThough Mao played a crucial role in encouraging the Cultural Revolution with his words, it was largely an organic revolt from below against much of the ruling class to preserve the process of building Communism in China from those undermining it.\n\nWhether or not you approve of them politically, Mao and the Cultural Revolutionaries were indisputably correct about where the CCP was heading and what it meant for the living conditions of the Chinese workers and peasantry. The Cultural Revolution failed to fully destroy the would-be ruling-class and a few year later began the Deng Xiaoping era of transformation of China into a capitalist state. Political power became more centralized and less democratic than it was in the 1960's. Many of the \"Capitalist Road\" bureaucrats and politicians who managed to hold on through the Cultural Revolution became very powerful and many of them and their children are now top officials and billionaires. Meanwhile, the huge improvements in life expectancy, infant mortality rates, education rates, income (and other indicators of standards of living) for the general population that had been made in the previous 30 years variously receded or slowed dramatically.",
"Prior to the revolution, China was the future of the current USA. the 1% had completely stomped the rest of the population into the ground and there was no real chance to move up. Income inequality and corruption ruled the day. Resentment towards the 1% had been growing for a LONG time. But the 1% ignored it and continued on.\n\nMao was part of the people who were tired and angry from being raped by the 1% for so long. So they revolted and let loose the frustration of the 99%. The higher chunks of the 99% were also punished for being brainwashed and perpetuating the 1% domination. They were like struts holding up the 1% and so the struts must be broken as well.\n\nIt is hard for such a HUGE power shift to take place without outright stomping the old guard. The old guard believes THEY are in the right and will certainly never stop trying to regain it. So Mao stomped them all out.\n\nSadly, nobody has really figured out how to have true happiness and productive motivation in a real socialist government. Most people start going \"why do extra when I get no extra reward?\".\n\nAlso Mao was no hero. He was wealthy born and profited immensely from the revolution. It is hard to know whether he really cared or whether he just wanted personal power and this was the avenue he found. He has many parallels to hitler and stalin and has killed 10's of millions of his own people through direct order and by pure incompetence.\n\nGenerally the 1% feel \"righteous\" about their position, that they are creating the greatness in their nation and that the nation and its people owes a debt to the 1% for doing so. ",
"If you kill off everyone with an education or an awareness of history it's much easier to brainwash a large population. Boils down to control. Communism is very big on heavy handed control of the populace. The Khmer rouge used the same methods to wipe out undesirable ideas. ",
"From what I gather here, Mao was fighting for the underdogs. He disliked the idea of inequality in wealth esp (when it usually depends where and to whom you were born to) and I can't say I disagree.",
"it's really odd to me that a country like China, that has such an (arguably, obiv) objectively interesting history could have gone through such lengths to hide it. To me, that speaks volumes about the culture vis-a-via say, eh, American? ",
"Cmon, am I the only person that read Ellen Pao?",
"It's simple, CONTROL! Less intellects = less oppositions. It also mean redistribution of wealth and land that benefit the government directly or indirectly through taxes or government ownership. When you are trying to control and unite as many low income people as china, drastic measures are needed. Either that or a China broken up like Africa with countries controlled by different warlords. Sharia law is adapted as the governing \"law\" in many countries in the middle east for similar reason. Its strict rules gives government control over its people. \n \nWhen you kill the thinkers, all you have left are followers.",
"My dad lived through these times before immigrating to Canada, he would tell me mostly about the famine stories, how there was no grass left in his hometown... ",
"Dictators often kill intellectuals, because it is they who will speak out, and represent the public intelligently. By purging all the smart people, you will only have left the ignorant, and they are much easier to control.",
"The central planners determined that the old traditions were responsible for the problems. So it started out just as a progressive movement. Then when nothing got better, and actually got worse, then they just started killing people. \n\nThen as the progressives continued to create failures after failure, people would starve because of food shortages. The central planners thought they could plan the economy better than letting the people in the market freely choose for themselves. \n\nSo in a progressive effort of getting rid of the old traditions, people were ordered to make their own tools and food. It was even planned so that a certain farmer would make an anvil and hammer, not a blacksmith... \n\nSo the anvil and hammer were terrible... But that didn't stop them. \n\nMeanwhile, food shortages just conveniently happened to the people that the progressives didn't like (the people who believed in the \"old ways.\") \n",
"Governments do not like it when their people are able to think critically and come to their own opinion about things, especially government. Intellectuals (educated people) often criticize governments and are seen as a threat to be neutralized, especially at the levels of higher education - universities and colleges.\n\nBeware the government representatives that speak ill of higher education.",
"What I find funny is, you kill forty people and you are a depraved murderer, the scum of the earth. You kill forty million and you are still referred as Chairman Mao, not as Bloody Mao. Funny how the mind works.",
"The famine was so bad in some villages that there was a market for dead children. They'd take their dead child to the market and exchange the body for another dead child. That way, they didn't have to eat their own children.",
"Originally as others have noted he was trying to purge china of the four olds. Basically their culture,history etc the closest equivalent would be what the Khmer rouge attempted with year zero. However towards the end though the original aims and goals went out the window, as the party tried to make Mao irrelevant, they wanted him to be a godlike figurehead someone revered but neutered concerning actual policy and control. That's when the greatest excesses of the cultural revolution occurred because Mao retaliated, he more or less gave his wife in others like the red guard who were loyal to him free reign to do what they pleased, at certain points mini civil wars were occurring throughout china. During the cultural revolution, china's government for better or worse was non existent in concerns to controlling what was going on. I still feel sadness reading about the destruction of millennia of history in a few short years. Temples, artifacts all gone, i believe at one point some people even tried to target the forbidden city for destruction which point only due to the some elements of the Chinese PLA intervening was this prevented but it's been a few years since i read up on that incident so i may be a little off. \n\nThere's a really good book i read called the wild swans. It not only goes indepth into the history surrounding the horror of the great leap forward and cultural revolution but also gives a nice view of china during the warring warlord period, the japanese vs communist vs nationalist period through the eyes of three generations of women in a chinese family. The author was a red guard when she was younger, her father and mother were top communist officials who ended up being denounced during the revolution, her grandmother was a warlords concubine who had her feet binded it's a fascinating history i recommend if you want an in-depth and easily accessible read concerning the history to pick up the book for a first hand account of Mao's lunacy _URL_0_",
"If you kill all the people who teach there won't be people to teach. People easy to control if they dumb.",
"A totalitarian regime does not benefit from a well-educated populace, people who can look at situations analytically and make decisions for themselves.",
"Classic Communism was always set in motion with an \"agrarian/workers revolution\", i.e. purging society of the middle and upper class, the intellectuals, emptying cities and mass shift to an economy based on agriculture.\n\nTeachers and other \"learned\" people who could inject counter-productive ideas into the population are a clear and present danger to this idea, and since farmers have no use at all for any formal education, teachers were dispensable.\n\nSee also: Pol Pot, Khmer Rouge, Kampuchea, The Killing Fields",
"This is the most interesting, informative, and thought provoking post I have found on reddit. \nThank you. ",
"don't all dictators kill intelectuals since they're the ones supposed to question what is wrong in one society.",
"He didn't and had no interest to do so. The Cultural revolution was not a top-down organised process carried out by party officials. It was more top-bottom-up attempt to involve the people in the continuation of the Revolution. Ordinary workers and students were encouraged to stand up by themselves against bureaucracy, reactionary though and be more involved in the communist ideology in general.\n\nThe party propagated revolutionary slogans like \"What men can do, women can do\" and some instructions to local cadres. The problem is that the process was very decentralised so the Cultural revolution was not carried on like expected everywhere. Factions that mirrored conflicts in the Party emerged that were not controlled by either communist officials or the military.The one that is truest to what Mao and his support indented established communes, spread propaganda and things like that. In some place people went too far and committed atrocities. Sometimes factions fought each other. "
]
}
|
[] |
[] |
[
[],
[],
[],
[
"http://www.ucpress.edu/book.php?isbn=9780520259317"
],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[
"https://en.wikipedia.org/wiki/Great_Leap_Forward"
],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[
"https://youtu.be/UUCEeC4f6ts"
],
[],
[],
[],
[
"https://en.wikipedia.org/wiki/Red_Guards_%28China%29",
"https://en.wikipedia.org/wiki/Quotations_from_Chairman_Mao_Tse-tung",
"https://en.wikipedia.org/wiki/Mao_Anying",
"https://en.wikipedia.org/wiki/Test_No._6",
"https://en.wikipedia.org/wiki/Four_Olds",
"https://en.wikipedia.org/wiki/Cultural_Revolution#/media/File:Cultural_Revolution_poster.jpg"
],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
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"http://www.amazon.com/Wild-Swans-Three-Daughters-China/dp/0743246985/ref=sr_1_8?s=books&ie=UTF8&qid=1454251993&sr=1-8&keywords=china+red+guard"
],
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[],
[],
[],
[],
[]
] |
||
lkjce
|
Why are red and blue wavelengths of light most useful to photosynthesis?
|
Why is this? Using my own knowledge of wavelengths of light, it would be logical to conclude that Indigo/Violet would be the most useful because they have the shortest wavelengths.
|
askscience
|
http://www.reddit.com/r/askscience/comments/lkjce/why_are_red_and_blue_wavelengths_of_light_most/
|
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"Look [here](_URL_0_) Notice how on the left side of the total absorption graph everything is absorbed? If you are a plant, you don't want to be absorbing things in that region... so violet is less efficient than things to the right of it.",
"Look [here](_URL_0_) Notice how on the left side of the total absorption graph everything is absorbed? If you are a plant, you don't want to be absorbing things in that region... so violet is less efficient than things to the right of it."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/File:Atmospheric_Transmission.png"
],
[
"http://en.wikipedia.org/wiki/File:Atmospheric_Transmission.png"
]
] |
|
5x1j5f
|
why can we still smell cigarette smoke i walk through when not breathing in?
|
When there's a bad smell around me, I do what anyone does and either breath through my mouth or don't breath in at all.
Something I've noticed for years and also confirmed with other people that they experience, is when that bad smell is cigarette smoke I can still smell it, or atleast detect it.
This doesn't happen with any other bad smell.
What is it about cigarette smoke that's so, for lack of a better word, invasive?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5x1j5f/eli5_why_can_we_still_smell_cigarette_smoke_i/
|
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"The chemicals from cigarette smoke gets trapped in material (most likely fabric of some sort) and diffuses which is why you smell it. ",
"If you're not inhaling, you smell almost nothing. Air needs to impact your olfactory nerves to register. So if you smell it, it might be because you're expecting to smell it? Or, like u/OldBirdWing mentioned, it could be sticking to your clothes. ",
"depends on what you mean smell. It could be the smell you get after you leave the area, as the smell gets stuck to your clothes.\n\nor the tiny tiny amount of air that would normally diffuse in and out of your nostril that lets you smell it"
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
4i7s71
|
how do journalists find people?
|
Police and other law enforcement agencies obviously can find people through using all their records and things of that nature but how are journalists able to find just about anybody?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4i7s71/eli5_how_do_journalists_find_people/
|
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"Many people can be found through a phone book or a simple google search. Or you can call the company where you heard they work, or the school where you heard they study. Also, you can ask their current and former friends.",
"A lot of work.\n\nIn the early 90's I did my work experience at a local newspaper. Back then, in the pre-google days, if we needed to find someone, we'd grab a phonebook and just start calling everyone with the same surname.\n\n",
"They often can't find people.\n\nAnd when they can't find a person, they don't write a story about it, and you never know about. If they look for 100 people, and only find one, you only get to read the story about the one they did find.\n\n",
"Lexis-Nexis is a commercial database you pay for access to. Basically, it's a searchable copy of just about every public record, and some which aren't. Property records, legal proceedings, possibly credit reports and junk mail mailing lists."
]
}
|
[] |
[] |
[
[],
[],
[],
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|
2rtf7o
|
How thin (nanometer, atoms, etc..) can the human see, looking directly?
|
What I'm trying to ask is how thin does a plane have to be to not be visible to the naked eye? On the same question, how thick does it need to be to appear visible ?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2rtf7o/how_thin_nanometer_atoms_etc_can_the_human_see/
|
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"The visual resolution of the human eye is about 1 arc minute.\n\nAt a viewing distance of 20″, that translates to about 170 dpi (or pixels-per-inch / PPI), which equals a dot pitch of around 0.14 mm. LCD monitors today have a dot pitch of .18mm to .24mm.\n\nEach persons vision is slightly different and some people have better vision then others. Experts believe on average that the naked eye — a normal eye with regular vision and unaided by any other tools — can see objects as small as about 0.1 millimeters. To put this in perspective, the tiniest things a human being can usually see with the naked eye are things like human hair (with the naked eye and under a microscope) and lice (with the naked eye and under a microscope).\n\nWhy is this the case? Lets do the math!\n\nThe finite size of the pupil sets upper limit on eye's resolution. \nIf the resolution of the eye is the smallest object the eye can see. This is limited by the diffraction limit, which is approximated by the formula,\n\nDiffLim=~1.22x(L/D)\n\nWhere \nDiffLim is the angular size of the object.\nL is the wavelength of visible light.\nD is the diameter of the pupil.\n\nThe angular size is just the ratio of the object's size versus the distance to the object.\n\nThe normal pupil size of a human eye is 4mm, which sets a minimum angular resolution of the eye at 2x10^{-4}rad. Obviously, we want to put small objects as close to our eyes as possible to be able to see them, but there is a minimum distance for comfortable viewing which is roughly at 25cm.\n\nThis works out to a size of 0.04mm if the human eye is diffraction-limited, but unfortunately, our eyes do not work at this higher limit. However, a quoted figure for the smallest resolvable size is 0.1mm, just double the figure estimated here, showing that the diffraction limit is a crucial factor in visual resolving power.\n\nTo double check.\n\nNote that the separation of cones at the back of the human eye also effects visible resolution.\n\nLight must hit separate cones for our brain to interpret them as coming from two different 'dots'. The diameter of the human eye is about 25mm and the separation of human cones is 2µm. \n\nWe can calculate the angular resolution (8x10^{-5}rad) and use the minimum comfortable viewing distance of 25cm to determine the smallest resolvable object, which comes out to be approximately 0.02mm. Close enough to the quoted literature value of 0.1mm.\n\nThus, the answer is ~0.1mm in thickness, any smaller and your eyes will have trouble differentiating the plane from the sky. ",
"If you have a thin clear film, scattering, refraction and reflections dominate the view. So, you might still see the film even if it's transparent. For films that are thin enough, they are eventually translucent, since the probability per nanometer of any material to absorb light is finite.\n\nBut, the transition to invisibility at below 600 nm is not a boring fade-out. When the film is about the same as the wavelength of light (400-700 nm), it can resonate with the light, [to give a color](_URL_0_). This is the so-called structural color, and can be deliberately produced by coatings. [Example here.](_URL_1_)\n\nFilms that are even thinner (nanometers) than this are transparent, but they still scatter light.",
"you can *discriminate* two points (or lines, or planes viewed edge-on) that are separated by at least 1 minute of arc (if you have *perfect* acuity); what this comes down to is viewing distance times tan((1/60)) = .0166. So, at a distance of 57 centimeters (a convenient distance since at 57cm 1degree is 1cm), you can distinguish two points separated by 0.0166 cm. If you fixate right in front of your face (say, 8 cm away), you can distinguish two points separated by about 23 microns!\n\nbut if you're looking at *one* point, or *one* line (or *one* plane, edge-on), there's no lower limit. It all comes down to contrast - you can see stars in the sky, and they're... well, they're super small, basically infinitely small points as far as you're concerned. same would be true for a plane - if you had a sheet of atoms 1 atom thick, I think you could see it if the lighting was right (need a physicist for that one)."
]
}
|
[] |
[] |
[
[],
[
"http://en.wikipedia.org/wiki/Thin-film_interference",
"http://www.sciencedaily.com/releases/2014/09/140930111413.htm"
],
[]
] |
|
17t2j4
|
if gps satellites lose time due to the lesser effect of gravity, why can't we just adjust the clock speed to make up the difference?
|
I understand GPS satellites lose time because there is less gravity in their orbital paths. I'm also under the impression that we resync their clocks regularly. Are there too many other variables (like the moon) to adjust the clock speed, what would those variables be? A mechanical watch can be set a little fast or a little slow and gain/loose time each day, why not the satellites?
edit: was at my phone and couldn't mark answered until now.
Or have I got this all wrong?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/17t2j4/if_gps_satellites_lose_time_due_to_the_lesser/
|
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"We *also* have GPS satellites adjust their clock speed themselves. But there are a lot of variables, so it would take a lot of processing power to compute the adjustments exactly; it's much more efficient to just make them kinda accurate and resync regularly.",
"GPS clocks are actually quite drifted from true atomic time. \"Time\", as we know it, has to do with the position of the earth as it orbits the sun. This rate is slowing down, and it doesn't align perfectly to a day. So we fiddle with our time, by adding leap seconds and leap days to make up for it. This messes up time computation - even makes it nonlinear - for the sake of making time understandable to people.\n\nGPS satellites really don't care about the time as it relates to how earth's rotation relates to the orbit around the sun. All they care about is \"when\" they will be in various places in the sky. It makes more sense for the GPS satellites to use a simpler measurement of \"when\" because it's easiest to do the position computations without having to worry about leap time.\n\nInteresting related material that explains this a bit more:\n_URL_0_\n\nAddendum:\nNot directly related to the question, but it's super-important that GPS satellites have a synchronized clock, because a GPS receiver determines position by looking at the time difference reported by each satellite. The difference is only caused by the communication delay between the satellite and the GPS receiver. The \"correct\" time doesn't matter at all - as long as the satellites are synchronized."
]
}
|
[] |
[] |
[
[],
[
"http://what-if.xkcd.com/26/"
]
] |
|
3duv58
|
What do historians think of Foucault's "Discipline and Punish"?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/3duv58/what_do_historians_think_of_foucaults_discipline/
|
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"I'll start by re-posting here several segments I've previously posted on punishment and Foucault.\n\n > His influence is hard to *overstate* ... he's frequently accused (and rightfully so) for his very selective historical sources, and for not doing sufficient archival work, but in general he remains an essential touchpoint for almost every historical work on punishment and incarceration [...] There are large caveats to these citations, which are often empirical objections, such as those pointed out by Spierenburg (*Spectacle of Suffering*, 1984). Elsewhere, it's true that many historians often cite Foucault's various writings without much further commentary, as if he's simply a necessary inclusion (and I'm certainly not alone in making this somewhat sad observation). [...] it should be made clear that you simply can't detach Foucault's theory from his historical works. He doesn't just use them as case studies for his thoughts; they were organic processes of writing, through which his practices and notions of archaeology and genealogy were developed. We have to be uncomfortably reductive to provide a synopsis of such a formidable theorist, but to phrase it simply, you have to understand that his histories were often long-scale, pulling back the historical strata—not solely in events but in what he called epistemes, or the epistemological boundaries of a culture’s discursive constructs of, say, the human body, of sex, of the purposes punishment, or of man itself—to explore the winding-through-history of such concepts. And you can really only imagine these by looking at them in practice: in Discipline and Punishment, he outlined the evolution of Western punitive thought from public punishment to incarceration as the individual subject replaced the communal, concomitant with the internalising process of panopticism ... (_URL_0_)\n\nThat's all a bit tangential, but perhaps might helps some understand a little where I'm coming from. I'm more interested in the punishments and violence of the penal system rather than the move towards incarceration, so what I'm saying won't perhaps apply to others; in other words, I view his work from the early modern perspective, which with *Discipline and Punish* is concerned in many ways only for the sake of argument (\"pre-modern justice was less a serious object of study in itself [for Foucault] than an elegant theoretical foil to the logic of modern punishment\", as Friedland, *Seeing Justice Done*, points out). But I think we have to pair him with other major theorists, in particular Norbert Elias, before anything truly productive is produced. For one, his claims of the early-modern executions' production of 'terror' for the public to reinforce sovereign authority ('Part 1: Torture' of *Discipline and Punish*) draw on Damiens' excruciating and drawn-out death - a very extraordinary case - to make more generalised arguments, which don't really hold up in ordinary acts of punishment (see e.g. Friedland, or Bastien, *L'exécution publique à Paris au XVIIIe siècle*, amongst many others, for varied challenges to this interpretation, including retribution, communal expiation, a return to deterrence and state consolidation, and so on). In this latter sense of its link to the state, secondly, you also need those like Elias to help link punishment to more concrete institutions and systems beyond Foucault's symbolic focus on sovereignty. Those like Spierenburg have therefore done amazing work to reinforce Foucault's thesis by combining it with Elias, while drawing analytical attention away from the former's almost too-blind emphasis on France, as well as underscoring how other forms of punitive spectacularity - and *not* executions and tortures - grew in strength in the 18th century (and furthered in more recent work by, as mentioned, Bastien, Friedland, Porret, Chavaud, etc.). As I wrote elsewhere:\n > ... see Pieter Spierenburg's now-classic *The Spectacle of Suffering* for an overview on spectacular punishment. Although a little dated, it holds its place firm as a go-to in this historical field of public punishment in early modern to modern Europe, and deals with the decline in capital and other visual corporeal punishments, drawing on Foucault's seminal Discipline and Punish -- which charted the 18th- to 19th-century transition from the physical infliction of pain upon the criminal's body to judicial reforms increasingly preoccupied with rehabilitation via incarceration -- and Elias' state-centred Civilizing Process, with a few revisions. (His introduction has a good summary and criticisms on these two 'giants' of the topic.) On the pillory itself, there are too many to list, and it depends what your geographical interests are: John Beattie’s Crime and the Courts in England (1985) is frequently quoted for his descriptions of the pillory as the ‘paradigm’ of the era’s penal practice. A lot of other publications are journal articles behind paywalls, but if you do have access, see as just two examples McGowen, ‘From Pillory to Gallows: The Punishment of Forgery’ (1999) or Greene, ‘Public Secrets: Sodomy and the Pillory in the 18th Century’ (2003). (Those are completely arbitrary suggestions, by the way; there are many others, needless to say.)\nTo return to public penalties in general, there have been many possible answers proposed by historians and criminologists alike as to the causes of this growing antipathy to spectacular punishment. Squeamishness is one; others include the mounting control of the state, legal reformers' awareness of deterrence's failings, growing concerns for bodily integrity, and so forth. Some of these are problematic in their own respects. Shifts in elite sensibilities were not always concomitant with those of the lower classes when measured against continued popular attendance at executions during the 18th century, for instance. Others, like Foucault's narrative, have been found wanting; while discourses of pain and the body are important, for one, their dominance as causal factors might be reduced in favour of the sensibilities argument, since, as many have pointed out, hiding punishment did not necessitate its abolition. The death penalty is a notorious example of that, and I don't just mean in terms of the USA. (France's last guillotining was in 1977, for example.)\n(_URL_1_)\n\n[Edit: fixed typos]"
]
}
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[
[
"https://www.reddit.com/r/AskHistorians/comments/2z2wlc/what_are_your_thoughts_on_michel_foucaults_impact/cpfe4tc",
"https://www.reddit.com/r/AskHistorians/comments/31w9yd/what_happened_to_public_shaming_why_does_the/cq6ha1v"
]
] |
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