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942aft | how do sodium and potassium help aid in hydration? | I feel like I have a vague understanding of the sodium potassium pump but can't fully conceptualize how this relates to (or if it does at all) hydration, or water getting into the cells. If the cells pump sodium out and bring potassium in, wouldn't the water stay outside of the cell? To go further, how does the sodium get into the cell in the first place? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/942aft/eli5_how_do_sodium_and_potassium_help_aid_in/ | {
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"You're on the right track with the sodium-potassium pump in relation to how muscle utilize the electrolytes.\n\nFor actual \"hydration\", sodium and potassium don't directly help with hydration. As muscles do their thing, and your body sweats, it loses electrolytes (sodium, potassium, etc) so drinking fluids with those helps to replenish that which was lost.\n\nHydration is more like osmosis, or water going to an area of a higher concentration to try to \"even things out\"; if your blood vessels have a higher concentration of sodium than the cells do, water will move from the cells to the blood vessels to try to equalize the ratio so that the vessels and cells are about equal, and vice versa.\n\nSodium gets in to cells via the sodium channel, or a \"doorway\" designed to move sodium from one side of the cell membrane to the other. Some things, such as water, pass through cells without issue. Others, like sodium, needs a door. Still more, like sugar, needs a \"key\" (insulin) to move in to cells. "
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24djk3 | How violent were the Middle Ages in England? Was crime and violent crime more common than in subsequent periods? | We are often fed a view of the middle ages as being violent and a time of crime and murder. Was this the case? Were the Middle Ages actually violent or were they a time or relative peace?
EDIT: I realise someone already asked a similar question about the Middle Ages but this was related to Game of Thrones... I'm asking more specifically about violent crime in general and not in relation to a TV show. Thanks! | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/24djk3/how_violent_were_the_middle_ages_in_england_was/ | {
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"I'm a history student and this was one of the questions we got asked this year in our 'History of Violence' module. \nThis probably isn't the answer you wanted to receive but to be honest it's difficult to say, because it depends how you look at it.\nFor example, there was a lot more a risk of being murdered as you went about your daily life then, just because we didn't have as many safety measures then as we do now (street lamps, cameras etc.), and it goes without saying that punishment was a lot more violent in the Middle Ages and you were punished severely for minor things.\nBut if you look at the last century alone for example, we've had two world wars, genocide and have had the threat of nuclear war. In my opinion at least, while people in the Middle Ages faced a lot of violent behaviour, it wasn't able to be carried out on the same scale as it is today. If you take an average bomb from an aircraft as an example, it's capable of doing a lot more destruction from quite a large distance away than say close quarters combat with swords. It's also capable of killing more people in a shorter amount of time.\n\nWhile it is quite controversial and I don't necessarily agree with his theories, Steven Pinker wrote a book called 'The Better Angels of our Nature'. _URL_0_\nBasically, he argues that over time we have gotten less violent. But looking at the Middle Ages specifically, he says they WERE violent because of religious intolerance, the government was divided between barons, knights etc. so there was a lot of fighting to regain power, and he also mentions how a lot of entertainment in the Middle Ages had an element of torture - such as jousting or animal baiting. But he describes the Middle Ages as fairly civilised and thinks they were less violent than humans prior to the Middle Ages.\n\nFinally, it sort of depends on what you consider 'violence'. Do you consider it physical violence such as murder alone? Or is persecution and prejudice violent behaviour too? Does violent behaviour include slaughter of animals, or just against humans?\n\nI hope I managed to at least attempt to answer your question. Like most things in history there's different ways of looking at a topic and no definite answer!"
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1k9puu | Historians of China: Are there any books you recommend on the history of taoism? | I'm curious to this, because it seems an interesing topic. Taoism itself is not talked about enough. I was told by a taoist friend that the original taoists believed in the tao and meditated, but later it became mixed with the local folk religion. I was wondering if this is true, but I also want to read about the history of the religion itself. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1k9puu/historians_of_china_are_there_any_books_you/ | {
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"Well, you are in luck, because the quality and number of English language books on daoism in China has increased significantly in recent years. My own journey with daoism (which began about twenty years ago) was much more circuitous than it could have been just ten or fifteen years later. \n\nMore in a moment. Just have to dig up the available sources, most of which are packed for moving next week. \n \nOk, back. \nHere is the newest and best source for a non-specialist - [Livia Kohn's *Introducing Daoism*](_URL_0_). It is readable, comprehensive, and best of all, relatively cheap. It is not a reference text, so that keeps the price down. \n\nAs u/grass_skirt mentioned, Robinet's work is also excellent, but more in depth and academic than the Kohn introduction. \nIf you get really excited and into it - Kohn edited a fantastic two volume grad-level text - [Daoism Handbook](_URL_1_) - but it is better read at the library, unless you want to spend $200+. \n\nWhat you were told by the Daoist is not entirely wrong, but it is such a distillation and simplification that it bears only passing resemblance to *some* of the story of Daoism in China. \nKohn's book lays out all the major strands quite beautifully. Enjoy!",
"These might be of interest:\n\nIsabelle Robinet: *Taoism: Growth of a Religion* (trans. Phyllis Brooks); Stanford, Calif. : Stanford University Press, 1997. \n-----*Taoist meditation: the Mao-shan tradition of great purity* (trans. by Julian F. Pas and Norman J. Girardot); Albany, NY : State University of New York Press, 1993.\n\nThere are references in the *Zhuangzi*, one of the early (supposedly pre-religious) Taoist texts, which seem to be about meditation, known as *zuowang* 'to sit and forget'.\n\nMy understanding is that the modern terms \"philosophical Taoism\" (*daojia*) and \"religious Taoism\" (*daojiao*) are problematic when we try to trace their use historically. Sometimes we are dealing with a bibliographic category, sometimes with a social movement, sometimes with things whose definition as either *daojia* or *daojiao* do not at all match the way we use the terms today. \n\nNathan Sivin's 1978 essay ['On the Word \"Taoist\" as a Source of Perplexity'](_URL_0_) is a classic exposition of the problem. I'm not clear on how the state of the field has progressed since he wrote that essay, however. \n\n/u/lukeweiss will be more helpful in this regard! \n\nEdit: Regarding folk religion: I think the penchant for mixing philosophy with 'folk' mythology is clearly present in the *Zhuangzi* also.\n",
"If you're interested in learning more about the history of the religion, I think that the books Lukeweiss has recommended will serve you well. If you're interested in studying some of the primary sources in greater detail, to understand the key early texts of Daoism (namely, the Daodejing and the Zhuangzi), then here are a few recommendations for you. Of course, you might choose to read these two books before studying them in greater detail, in which case, look [here](_URL_3_) or [here](_URL_5_) for the Daodejing, and [here](_URL_0_) or [here](_URL_8_) for the Zhuangzi. Now then:\n\n[Allan, Sarah. The Way of Water and Sprouts of Virtue.](_URL_4_)\n\n[Coutinho, Steve. Zhuangzi and Early Chinese Philosophy: Vagueness, Transformation and Paradox.](_URL_2_)\n\n[Religious and Philosophical Aspects of the Laozi. Mark Csikszentmihalyi and Philip Ivanhoe.](_URL_9_)\n\n[Schwartz, Benjamin. The World of Thought in Ancient China.](_URL_1_.)\n\n[Slingerland, Edward. Effortless Action.](_URL_6_)\n\nThose are the first few books that are coming to mind - they'll certainly help you get started on understanding these important Daoist texts. I think that the Slingerland book and Benjamin Schwartz's book might serve you better as a general introduction to important ideas in Daoist texts, and then the other books can help you delve even deeper. Although, if you are more interested in learning about the history of Daoism than the careful study of early Daoist philosophy, I definitely have to second Lukeweiss' suggestion of [Introducing Daoism](_URL_7_)."
]
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"http://www.amazon.com/Daoism-Handbook-set-L-Kohn/dp/0391042378"
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"http://www.amazon.com/Zhuangzi-Early-Chinese-Philosophy-Transformation/dp/0754637301/ref=sr_1_1?s=books&ie=UTF8&qid=1376405361&sr=1-1&keywords=coutinho+zhuangzi",
"http://www.daoisopen.com/DDJTranslations.html",
"http://www.amazon.com/books/dp/0791433862",
"http://ctext.org/dao-de-jing",
"http://www.amazon.com/Effortless-Action-Conceptual-Metaphor-Spiritual/dp/0195314875/ref=sr_1_1?s=books&ie=UTF8&qid=1376405433&sr=1-1&keywords=effortless+action+slingerland",
"http://www.amazon.com/Introducing-Daoism-World-Religions-Livia/dp/0415439981",
"http://terebess.hu/english/chuangtzu.html",
"http://www.amazon.com/Religious-Philosohical-Aspects-Chinese-Philosophy/dp/0791441121/ref=sr_1_1?s=books&ie=UTF8&qid=1376405387&sr=1-1&keywords=Religious+and+Philosophical+Aspects+of+the+Laozi.+Mark+Csikszentmihalyi"
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16kgcm | do abusive parents produce abusive children, or submissive ones? | It would make sense that an abused child would live life fearfully, but it also makes sense that abuse happens in unbroken cycles. Is one of these right? Or possibly both? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/16kgcm/eli5_do_abusive_parents_produce_abusive_children/ | {
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"They can produce fucked up kids who can be submissive and/or abusive at different places in their lives.",
"In cases of abused children, generally you end up with both situations arising. If a child is abused they can start to self identify as a victim and start to display learned helplessness - a state where they are convinced that no matter what they do, they're going to still be victimized and terrible things will continue to happen. \n\nAs an example of this consider a child that is beaten under the pretense of not cleaning their room. After the beating they clean their room and make sure everything is nice and tidy and start to feel pride in their accomplishment. After this they are again beaten or otherwise abused, the abuser using another pretense to justify the abuse. The child was expecting to be rewarded (even subtly) and was punished again. As this continues to happen the child will learn that no matter what punishment will happen and end up resigned to their sad predicament. This explains why they can be seen as more passive and often times don't work to try and make their situations better/end up exhibiting self-destructive tendencies.\n\nOn the other side of the coin, an abused child is being taught (incorrectly) that the abusive behavior is the response for a wide range of situations. Consider that you're a small child and you touched your father's prize bowling trophy. You thought it was just a toy and wanted to play with it, but he beat you for touching it. After enough incidents of things like this happening you start to associate touching other people's things with a beating and you accept it as fact. Now, one day in school a classmate touches one of your toys when you didn't want them to. Since you have been taught that physical attacks are the response in this situation, you hit them. \n\nBeing abused is a double edged sword. Not only are you more likely to be violent, you're also less likely to seek help since you don't believe you'll get help or that the help will be useful. You've learned that nothing will please your abusers except for their abuse. You begin to learn that using abuse is the appropriate response to a lot of situations and thus start to emulate abusive behavior.",
"It's offensive that you assume that there isn't a third option, and that people who were abused as children are utterly helpless to get better. We're not. We're in control of our own lives. It's hard for us, but we can do it, and regularly do. Just because some of us use that misconception as an excuse for what they find themselves doing, doesn't make it true.",
"There are more options, but it got me thinking about myself...\n\nThis isn't a sob story. I'm a pretty well-rounded and happy person.\n\nI was raised by a mentally and emotionally abusive mother, who was raised by a mentally and emotionally abusive mother herself and a physically abusive father. As a child I was very submissive and afraid. Some people thought I was shy, and to a degree I was, but I'd mostly become accustomed to being fearful of opening my mouth and saying...well...anything really. My mom has clinical issues that left her with the inability to show love (and maybe feel it, I'm not sure) and no matter what I said she found a way to twist it into me doing or saying something threatening. She has openly expressed a hatred toward me all my life, for no real reason other than she has no other emotion. Obviously there is more to that but...well I'm supposed to pretend you're 5 so I'll move past it.\n\nSo again, I was quiet and submissive and afraid into my college years. After 18, 19, 20 years of being submissive, something snapped. I got angry. My body, mind and heart was sick of it. My mom was less of an influence on me seeing as I lived on campus and suddenly I had power. Control. Of myself. But also, if I was loud enough, I could have that power and control over other people. I became cynical and biting. That \"don't take sh*t from nobody\" mentality turned into me shutting people down before they had a chance to oppress me in any way. By doing that, I became abusive. Not to the degree my mother ever was. And I'm not even sure my friends would call it \"abuse\" if I asked them. Maybe mean or bitchy. I didn't know how abusive I was being till I saw it in the faces of my friends. I saw my former self in their faces. God that killed me. \n\nIts like this: for 20 years my mother was holding me under water, angrily and psychotically shoving me under the surface with a menacing grin on her face. Then somehow I got free, swam away and took a breath of real, fresh air. But when I looked up I saw other people's arms hovering over me, not necessarily motivated to push me back under water, but definitely positioned in the right place to do it. And I refused to go back under that water. So I scratched and clawed at those arms and bent them out of my way so I'd never be without oxygen again. \n\nNow I have to keep it in check. I can sense when I'm getting a little too anxious and frustrated and I walk away from situations where I might feel oppressed. I am always worried I will turn into my mom. But I think it is my system of checking myself and being constantly reflective of my emotions sets me apart from her. But I know what I'm capable of and it scares me. I will probably never have children because of it. "
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j2flh | can someone please explain exactly what a 'realist' person is? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/j2flh/can_someone_please_explain_exactly_what_a_realist/ | {
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"Sorry, but could you clarify? In what situation did you hear this being used? International politics, US politics, everyday life?",
"A realist is best seen as an opposite to an 'idealist' (someone who is focused on ideals rather than the practicalities of life). A realist therefore views the world \"as it is\" and doesn't see it in idealised or romanticised way.\n\nHope that helps!"
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1oqd5d | Historians: What recently available source/material are you most excited about? | It seems historians are all about sources and materials, so what's the hot new thing in your field?
Be it declassified documents, opened archives, unearthed artifacts or discovered manuscripts, what's making your historian's heart beat faster? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1oqd5d/historians_what_recently_available_sourcematerial/ | {
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"[Richard III's body](_URL_1_) found under a parking lot.\n\n[Roman coins](_URL_0_) found in Hertfordshire.\n\nMore broadly, I anticipate a huge amount of stuff to be coming out in the next few years on Magna Carta and the surrounding period, too, since its 800th anniversary is coming in 2015. In addition, libraries are digitizing medieval manuscripts more and more rapidly every year, which is wonderful for those of us studying medieval Europe who don't live in Europe.\n\n",
"Rather dully, I'm most excited about a database. \n\n_URL_0_ - the National Archives recently made the (searchable) writings and correspondence of the U.S. \"Founding Fathers\" available for free online. I don't study the Founding Fathers, but it's already proving to be a tremendous resource. The annotations and biographical sketches attached to correspondence are particularly helpful for quick information on certain figures in early U.S. history.",
"The [treasure](_URL_0_) found in the unopened rooms of an old temple in Southern India (Kerala).",
"The recent dig at Jellinge in Denmark, it haven't really been made public yet, but some interesting discoveries have already been made. It makes me literally shiver with joy."
]
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"http://www.bbc.co.uk/news/uk-england-beds-bucks-herts-22794839",
"http://www.bbc.co.uk/news/uk-england-leicestershire-21063882"
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"http://www.newyorker.com/reporting/2012/04/30/120430fa_fact_halpern"
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|
bvnzyy | why do some large, multimillion dollar companies have so much trouble making a website that works well on mobile ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bvnzyy/eli5_why_do_some_large_multimillion_dollar/ | {
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"Those are usually riddled with ads, adware, tracking stuff for future ads and adware etc. Most news sites are now because that’s the only way they can monetize it without subscription fees",
"There are a lot of potential aspects to this, but I'm a software developer who used to work for a giant digital agency making those multi-million dollar sites, and it is insane how much overhead and waste there is with companies that throw that kind of money around.\n\nOne of my last projects before I left, a company literally paid for me and a team of developers full time as contractors through my agency, which means they were paying at least a few hundred an hour each, for almost 3 weeks, for us to sit around watching YouTube videos while they figured out what they wanted us to work on. Then once you do get to work, there are so many stakeholders and managers with conflicting priorities that it can become nearly impossible to make meaningful progress towards a streamlined product. \n\nTLDR: Paying multiple millions of dollars for a website can sometimes net you a pretty mediocre, bloated website with a lot of consultant travel and expensed business lunches.",
"The management doesn't know shit about websites, they just tell the designer, I want this and that and this and that and these things too, and I want to make money from ads, lots of money.",
"Many of them want to steer you towards the app, which they have more control over and can collect different kinds of data.",
"It is difficult and expensive. New web site designs take years, and little of it is affected by skilled programmers.\n\n & #x200B;\n\nIt is very hard to design a web site for multiple stakeholders with differing priorities. And most large companies have a range of priorities. That is because they have multiple products. For example, Apple needs to balance the needs of the iPhone and the Mac products. Chevy has to balance between trucks and sedans. So a \"new\" web design is the start of a lot of internal discussion and that takes time. There is no magic technology that makes all content visible at the same time. \n\n & #x200B;\n\nNext, the big company designs a site but doesn't have the budget to transfer the content. Or they have the budget, but not the required people, which often must be subject matter experts.",
"Because it's not their biggest market, financially. They are better off spending that money on the desktop site, which is where people go if they are serious about the service. The mobile site is used for the most part by casual browsers killing time, so it's a secondary consideration.",
"From my own experience non-tech oriented companies do not out a priority on tech so many times they dont allocated the resources needed to stay current. In addition they struggle to attract top talenr. If you were a hotshot web dev would you rather work for Newsweek or Netflix?"
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967xa7 | how do domesticated pets know they're pregnant, especially that they're not surrounded by a community of themselves who might be familiar with pregnancy? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/967xa7/eli5_how_do_domesticated_pets_know_theyre/ | {
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"Domesticated animals are much less capable of knowledge than humans, so I'm not sure exactly what you mean by \"know.\" Certainly pregnancy results in a number of physiological changes that can act as triggers for instinctive behavior. ",
"A cat I had apparently didn't know. She started squatting in her kitty litter for the first one. I moved her and when it was out I had to turn her nose around to get a whiff. That's all it took and her instincts took over so she started cleaning it and had several more. She knew to lay down to let them nurse."
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3nkbn8 | Could natives of British colonies migrate between each other and to England? | I'm sure that this post is filled with misconceptions, but nevertheless I'll ask it. Assuming that he had the resources, could a Kenyan or Indian hop on a ship and settle down in England without any trouble? I understand that immigration and emigration as a concept was probably wildly different 200-100 years ago, but were natives of colonised countries given British "passports" so to speak?
Thanks | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3nkbn8/could_natives_of_british_colonies_migrate_between/ | {
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"The first serious emigration from what you describe as the colonies to the UK took place post American War of Independence with American loyalists arriving in the UK. Subsequent to that immigration to the UK from the colonies was mostly that of seamen, mostly from the sub continent, \"paying off\" ships in the UK and, sometimes, settling in whichever port they were in. The main centres of this pattern of immigration were Cardiff, Liverpool, London and the Tyne, especially South Shields. This book has some details Coolies, Capital and Colonialism: Studies in Indian Labour History. Rana P. Behal, Marcel van der Linden, published at Cambridge. It is a bit polemical at times, but the essential story is correct. More here _URL_0_ also here The Invisible Empire: White Discourse, Tolerance and Belonging Again, this is a bit polemical with condemnation of the living conditions of lascars, whilst seemingly unconcerned, or unaware, that living conditions for British or other European seamen were pretty much the same."
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|
140buq | Who where the first people to establish the theory of evolution? | I would assume that many of these people are European, also who are the first poeples to accept these theories?
Edit: I'm not trying to say that I know nothing of the history of evolution, I know this basic information. I was wondering more about who are the first people to have a simple understanding of the theory of evolution, predating Charles Darwin and Alfred Wallace. Sorry for the confusion.
| AskHistorians | http://www.reddit.com/r/AskHistorians/comments/140buq/who_where_the_first_people_to_establish_the/ | {
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"I don't usually like to do this, but...\n\n[Charles Darwin](_URL_0_) and [Alfred Wallace](_URL_2_) are widely accepted as the two men who independently established [the theory of evolution by natural selection](_URL_1_). There had been theories before about how species might have changed and developed over time, but these men were the ones who theorised that this development might occur through natural selection.\n\nI've linked a few Wikipedia articles to get you started on the basics of this topic (if you don't even know that Darwin is the \"father\" of evolutionary theory, then you definitely need to start with the basics).\n\nI hope this helps.\n",
"There have been \"theories of evolution\" going back to [the pre-Socratic philosophers](_URL_0_).\n\nHowever, the idea of biological evolution didn't become \"established\" and \"accepted\" until Darwin proposed a workable mechanism. ",
"Al-Jahiz, in the 9th century, outlined some basic tenants of evolution:\n\n\"Animals engage in a struggle for existence; for resources, to avoid being eaten and to breed. Environmental factors influence organisms to develop new characteristics to ensure survival, thus transforming into new species. Animals that survive to breed can pass on their successful characteristics to offspring.\"\n\nThis probably sounds more similar to what Lamarck was saying than what Darwin eventually envisioned, though.",
"Ooooh, I got this!! The roots of what we consider evolutionary theory really begin with the theory of \"unity of composition\" proposed by Etienne Geoffrey Saint-Hilaire (zoology professor at the Museum d'Histoire Naturelle in Paris, France) in the 1830's. He basically said that all animal body plans could be reduced to common organ components—which indicated a common ancestry and supported the idea of \"transmutation\" (evolution). What came to be called \"Geoffreyism\" was influential in Europe outside of establishment circles in Britain, but its connections with revolutionary ideals prevented it from being accepted at Oxford and Cambridge...which is why it's not widely known about today. In 1844, a Scottish writer/publisher named Robert Chambers anonymously published a book called *Vestiges of the Natural History of Creation* which explained transmutation in terms that the average middle-class reader could understand. He wasn't a scientist, and obviously his writings still had a religious slant, but he brought together a whole bunch of scientific disciplines to flesh out the notion of transmutation. It was still highly controversial, but *Vestiges* sold hundreds of thousands of copies in several consecutive editions (more than Darwin's *Origins* ever did) and more than certainly paved the way for Darwin.\n\nRecommended reading: *The Politics of Evolution* by Adrian Desmond, and *Victorian Sensation* by James Secord (about the impact Chambers' *Vestiges*)\n\nEdit: What set Charles Darwin and Alfred Russell Wallace apart from their scientific predecessors was that:\n\nA.) Darwin provided a lot of good, hard, empirical evidence for evolution.\n\nB.) They provided a *mechanism* for evolution/transmutation: natural selection\n\nC.) Darwin's solidly \"establishment\" status (in contrast with the political outsider mentality of Geoffrey's supporters) made evolution respectable."
]
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"http://en.wikipedia.org/wiki/Charles_Darwin",
"http://en.wikipedia.org/wiki/History_of_evolutionary_thought#1859.E2.80.931930s:_Darwin_and_his_legacy",
"http://en.wikipedia.org/wiki/Alfred_Russel_Wallace"
],
[
"http://en.wikipedia.org/wiki/Evolution#History_of_evolutionary_thought"
],
[],
[]
] |
|
25d9jv | Is it possible to connect nerve cells to electrical wires? | This is a question I've been looking for an answer for since I was very young.
Now I know the state of prosthetics has vastly improved on the years and we already have prosthetics that can sense muscle contractions and can interpret movement of natural limbs to anticipate what movement should come next, but I've always wondered: Is there a way to either physically connect nerve cells (motor neurons) to electrical wires that would still allow the nerve cell to work and control whatever prosthetic limb is required?
OR
Is there a way to have nerve cells (motor neurons) in close enough proximity to the extrication wiring of the prosthetic limb, for an array the electrical wires are attached to to detect the neurotransmitter (acetylcholine is believe is what is used in muscle movement) and then affect action?
I'm also pretty sure this is a bioengineering question (or would it be more valid to show the distinction between the biological issues and engineering ones?)
I'll label this under biology, but if it should be elsewhere then sorry.
Also I have a feeling the answer to this is obvious, but it's always been a question that's floated around in my head (and I literally mean for as long as I can remember finding out what a prosthetic was, I won't say what age as most won't believe me but it's been a long time) | askscience | http://www.reddit.com/r/askscience/comments/25d9jv/is_it_possible_to_connect_nerve_cells_to/ | {
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"I can comment on the electrical side of this question, but not the biological side. \n \nFrom an electrical standpoint - sure, it's possible. It wouldn't be an ordinary circuit, of course. I suspect that the best bet would be to try and setup (highly sensitive) inductive coupling between nerves and a nearby sensor. Of course, you'd potentially run into all kinds of issues with biocompatibility, dealing with feedback, stabilizing the sensors, and a dozen other problems - but it's at least theoretically possible. \n \nSimilarly, as you suggest, it might be possible (I'm not terribly familiar with the biochemistry) to have a molecular sensor which completes a circuit in the presence of acetylcholine - effectively a chemically-triggered transistor. These already exist, designed to detect certain compounds or ions, but I don't know if they've been built for neurotransmitters.",
"Sure. In fact the key study that showed this was possible was done all the way back in [1939](_URL_2_). The technique they used is called a [voltage clamp](_URL_0_), and the short version is that you jam a wire into the inside of a nerve cell, stick another outside the cell and then fiddle with the voltage and current of the circuit you've formed. [Here's](_URL_1_) a textbook chapter that goes into a bit more detail.\n\nTo anticipate your follow up question of \"why did it take this long to directly hook a prosthetic to the neurons\", the answer is I'm not really sure. My guess would be that the problem lay more in the engineering challenge of making the thing work reliably and safely over a long time than in the theoretical concepts involved."
]
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[],
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"http://en.wikipedia.org/wiki/Voltage_clamp",
"https://www.inkling.com/read/medical-physiology-boron-boulpaep-2nd/chapter-6/electrical-model-of-a-cell",
"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2142005/pdf/671.pdf"
]
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|
28kszg | How was (Roman) Catholicism treated under British rule between roughly 1700 up to WW2? | I myself am 1/4th English, ancestrally, and my English family members today are Catholics, as there was about 100 years ago some Irish on that side, as well as obligatory Anglicanism. My Grandma's mum is 100% ethnic English (Anglican religion), and her dad was half Irish half Swedish, hence the Catholicism (my Swedish Great Great Grandfather converted from what we believe to be Lutheranism). Anyways, I've realized that Catholicism has had place in the British Empire for a long time, and when looking to the Irish this is one of the many reasons they once fought with the English over their island and rule. I'm aware the French Canadians had in treaty allowance of their Roman Catholicism, but was it so easily maintained?
When Ireland was under UK rule, was their Roman Catholicism purged, or was it allowed? What of the catholic French Canadians once they became subjects of the British Empire? What of Jacobian Scots, or the Spanish of Gibraltar? I'm very curious. I'm aware that nowadays it is no big deal at all your religion in the UK or Commonwealth, but I'm wondering how it used to be. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/28kszg/how_was_roman_catholicism_treated_under_british/ | {
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"Catholics in Ireland certainly were oppressed. Big time. There is a famous phrase that stems from the famine days called \"taking the soup\" This was basically you had two choices: starve or convert to Church of England. This is called souperism. Basically if you decided not to starve it was called taking the soup. \n\nCite:Thomas Edward Jordan (1998). Ireland's Children: Quality of Life, Stress, and Child Development in the Famine Era\n\nThen of course there's Oliver Cromwell. A man still cursed here in Ireland to this day. Cromwell started a bloody campaign against the Irish catholics and English royalists in 1649 and ended in 1653. Over 200,000 Irish are believed to have died during this time. All catholic land was confiscated during this time too in the \"Act for the Settlement of Ireland of 1652\"\n\nCite: \"Rather the region was chosen out of exaggerated respect for the impermeability of the Shannon line\".\n\nDuring this time there was a famous phrase \"Hell or Connaught\" Which meant you can either die or be exiled to Connaught. Connaught is a province in the west of Ireland. It has awful farming conditions. So really you were going to die regardless. "
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w8nau | What holds empires together ? | Why dont the conquered provinces rebel ? Why do people from conquered provinces agree to become soldiers for the conquerors, and help them dominate other people ? I guess the size of the army hold the empire together, but such an army cannot simply be made from the conquering race; the conquered must also provide people to the army. But why would they agree to do that ? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/w8nau/what_holds_empires_together/ | {
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"This is the question that destroys the image of Empires as being inherently evil states; why did so many people not only accept being part of an Empire but actively take part in them? Was it because the majority of humanity is/was evil or complacent? Or is it because Imperial states can offer something to people that is actually helpful?\n\nBefore I sink my teeth into this, a major disclaimer; I am not an imperialist. I don't think Empires are inherently evil, but I don't think that they're *nice* either. They are morally ambiguous, capable of both great acts of service and great acts of cruelty because they operate on such a large scale; anything they do is magnified in impact. It is certainly never, ever nice to be caught in an Empire's way.\n\nSo, let's turn to your first subquestion- why don't the conquered provinces rebel? In many Empires, the conquered provinces did attempt to rebel initially or even multiple times over the course of the Empire's lengthtime. For example, Egypt managed to gain independence from Achaemenid Persia not once but twice. In fact the examples are so numerous that I can't begin to list all of history's rebellions here.\n\nSo what do Empires do to solve this problem, as clearly many did not face constant revolts everywhere at once? Well, firstly most ancient Empires weren't able to centralise their administration as we would recognise; the King would only ever be able to really rule everything in a 50 mile radius around where he was at a given moment. This is a weakness in the state, but it was very often turned into a strength of Empires; lightness of touch. In many Empires, provinces, subkingdoms and whatever were relatively free to do as they wished as long as they didn't threaten the Empire and kept to their treaty obligations. In many cases, no direct governor was appointed- instead, a 'client-king' was installed; he was normally a local who had proven loyalty to the Empire in question, or who had been shown favour. Whilst these states obviously lost their ability to make foreign policy decisions, on a day to day level they could essentially continue as before.\n\nSpeaking of courting locals, many states went straight for the jugular and outright attempted to buy the loyalty of local elites. When I say local elites, I mean the people in a society who have control over social organisation, economics, everything like that. Imagine Medieval aristocrats for a relatively clear example of 'an elite'. Many Empires would court these elite groups on a case-by-case basis; an Empire controlling Babylon example might have the 'Emperor' act as King of Babylon, and repair the major temples of the city, whereas an Empire controlling a Greek city might guarantee to keep a certain ruling family in charge. By keeping the local elite onside, it meant that even if there was resistance in a given area Empires would face no *organised* resistance, which often meant it collapsed easily and quickly. Indeed, these local communities often began policing themselves whenever rebellion seemed to be on the cards.\n\nIn addition, starting from the very first Empire (Assyria) measures were adopted to attempt to counter the limited capacity of the Emperor to directly observe a situation. Efficient communication systems were created to drastically improve the ability of the King to communicate with his governors, generals and other important subjects; pony expresses were the method of choice from Assyria onwards, and did their job extremely well. Not only that, the creation of a vast bureaucracy enabled the Imperial state to actually begin to manage the *vast* amounts of data that would pour in every day. Also importantly, infrastructure was built; roads, forts, garrisons, capital cities, navies, all of these are ways of protecting interests, or speeding up movement.\n\nSpeaking of infrastructure, let's turn to the actual palpable benefits to ordinary people in conquered societies. This is the paragraph in which I basically list all of the nice things that Empires *can* do in the right situation. First and foremost, the world has been a very dangerous place. Not only can settled states declare war on you, but quite often people who were not in 'official states' might just turn up one day and decide to burn your crops, sack your city, plunder its treasures and leave everyone for dead. Empires can legitimately protect the states within its borders in a way that the state wouldn't be able to do on its own. This is one of the reasons to contribute troops to an Empire's forces, or to join them; you are not just protecting the Empire, you are by extension protecting your home as well. Speaking of which, the other major function of many Empires was to protect trade routes- this may not very exciting, but piracy has been a problem for a very long time, as have scams to cheat people out of money or to sink ships for profit. Empires can safeguard trade routes, and even increase the volume of trade by including the traders in an enormous network of exchange; there is a reason why so many cities became prosperous under Empires even without direct intervention. Empires also act as arbitrators in disputes between states- for all that the Empire is usually working for their advantage, that does not also mean they can't legitimately solve disputes. This is in itself a way of keeping peace- preventing disputes escalating into war. Indeed, if ordinary people were wronged they actually now had a level far beyond that of their direct king or governor to appeal to- appeals to Emperors for help have been around for a very long time. And this was actually sometimes effective- from a pragmatic point of view, if a governor was so hated that ordinary people were constantly sending representatives to complain about how harsh he was, it was entirely in the Emperor's interest to intervene and replace the man with a new governor. In most Empires, you actually had to consider what ordinary people wanted because you *needed* some element of co-operation in order to continue to exist.\n\nAnd last but not least in terms of tangible benefits, as I mentioned *everything* is on a larger scale. Glory you win on behalf of an Emperor is glory resounding throughout dozens of nations and cities, achievements are on an Imperial scale. An Empire might often invest immense amounts of money into making an area prosperous, in several cases they even spent time and money on making sure the local farming was up to scratch and invested in upgrades where possible (I'm mostly thinking of the Seleucid Empire here). If you're a trader, you have access to a vast regulated network where you are guaranteed safe passage and where a single currency is likely to be serviceable the entire time. If you're an intellectual, instead of being the biggest fish in a tiny pond you can suddenly find yourself in a whole lake; Empires are often breeding grounds for intellectual study as previous separate trains of thought encounter one another and begin to react to one another. If you count religion as part of intellectual thought, which in the ancient world I would, then just look at the Roman Empire between about 100 BC- 400 AD; the number of new religions formed from interactions of older ones is dizzying.\n\nEmpires are not nice, but they are not necessarily parasitic; there can often be tangible benefits to being part of an Empire, and even reasons to actively prefer to remain part of the Empire rather than attempt to leave.\n\nHowever, let's turn to the stick; the ways that Empires controlled their subjects. You are right in saying military dominance was not enough, but in the case of some Empires they were already militarily dominant before becoming an Empire; in the case of Assyria it was already the largest state in the Near East, with a standing army of 60,000 men by 800 BC. This is not an insignificant thing. Additionally, there are other ways of using that military force to control populations than as an army; many Empires garrison forces in cities and other areas using forts. When 600 armed soldiers loyal to the Emperor are in your city, you think twice before trying to get rid of them. Some Empires went further, and made locals responsible for billeting and feeding the soldiers. It's a canny if really nasty move. Also, taxes serve a twofold purpose; they enrich the Empire's core whilst also reducing the power of the local people being taxed. If you're being taxed and have troops in your house that *you* have to pay for in terms of living expenses, how do you even begin to consider resistance?\n\nAdditionally, the method of getting local elites on board is also a method of control. As is propaganda, like erecting massive *stele* in a city talking about your conquests- even if almost no-one there can read it, they are impressive to look at. And you divide and conquer; you move populations around to weaken them. However, a major caveat here- relocating populations was never used by early Empires as a punishment, the intention was usually that they had a new city and needed a population whilst also weakening the strength of the original people. Indeed, usually you ended up taking much of the local elite out of the original territory- the intellectuals often ended up in the Empire's capitals, the soldiers in the Empire's armies, the scribes in the Empire's administration.\n\nNow, this was a bit sprawling, and there's a few things wrong with this post; I've not used specific examples very much, it didn't dwell on any of the topics long enough, and sourcing it is going to be difficult because I'm piecing together my knowledge of multiple Empires rather than using specific texts that talk about all of them. So if either the OP or anyone else wants me to elaborate about any of this, feel free."
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7p8b4z | What were the reactions of early Jewish leaders to claims that Jesus had risen from the grave? Did they issue any refutations? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/7p8b4z/what_were_the_reactions_of_early_jewish_leaders/ | {
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"No, there are no reactions recorded.\n\nIn general there isn't a whole lot of written material about Christianity from Jewish sources in this period. Rabbinic sources do have occasional reference to Jesus, but they don't generally contain meaningful details. It's also an issue that the narratives put Jesus in the wrong time period. It is likely that they are literary ways to talk about Christianity in general, but because of distance from the context of authorship (and the massive amount of censorship that's happened of these passages) the exact meaning is not entirely clear.\n\nNone of these have any reference to a resurrection at all, much less any refutation of it. Really, the period was a very tumultuous time for Judaism in general, and most Rabbinic texts are intended for internal consumption. So it is somewhat unlikely that opinions on Christianity would be discussed very much.\n\nThe big exception to all this is Josephus, who was Jewish and wrote history texts. He did not refute Jesus's supposed resurrection, he actually records it as a historical event. But that passage is likely to have been either tampered with or entirely added by Christian scribes, since it would be somewhat incongruous for a Jewish author to write that, even at such an early time before Christianity and Judaism had become completely distinct religions."
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oer52 | Is it conceivable that we might tubes from the earth's surface into orbit and pump our smog or smoke from all the burning waste into the void of space to save the planet? | What might get in our way with this? | askscience | http://www.reddit.com/r/askscience/comments/oer52/is_it_conceivable_that_we_might_tubes_from_the/ | {
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27n5i9 | why aren't we supposed to lock our knees when standing? | I don't understand why it's bad to lock your knees when standing. How else are you supposed to stand? Like you're riding a skateboard?
**edit: thanks guys! just to clarify i actually don't ride skateboards, i was just thinking that skateboarders kind of bend their knees, and i was wondering if i was supposed to stand more like that** | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/27n5i9/eli5_why_arent_we_supposed_to_lock_our_knees_when/ | {
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"It reduces the blood flow to your legs making your muscles do more with less resources. I heard this all through basic training because it was one of the main factors that causes people to pass out while standing at the position of attention. Other factors usually included looking at bright lights and tilting your head back. Not sure why, but the only thing that comes to mind is blood flow. ",
"Med student here. It's (supposedly) bad to lock your knees as that in theory restricts venous return of blood back to the heart. Since veins contain one way valves and are extremely compliant, one good method of returning blood is through muscle contractions. Standing will cause pooling of blood in the lower extremities and with reduced supply to the heart, your cardiac output should decrease which limits the amount of blood going to your brain. Brain becomes hypo-perfused, lacking oxygen it requires, leading to syncope. ",
"I have stood like this everyday for the past 22 1/2 years. I work a job that makes me stand for 12 hours. Why have I never passed out?",
"It blocks blood flow (EDIT: returning from your legs, it starts to pool in your veins) as other people have said, and if you do faint and your knees are locked, you go down face first, with your face going down in an arc onto you nose (seen it many times at cadets), if your knees are straight ish but not locked and you faint, you just crumple and are less likely to fuck your face up. Seen soooo many people break noses/jaws/skin on their faces/chins from locking their knees and not wiggling their ~~feet~~ toes.\n\nBut that is on parade, when you're stationary for a while, day to day won't really do much for short periods.",
"What does \"locking your knees\" mean?",
"when you lock your legs you aren't using your leg muscles, your calves are like big pumps that move blood back up you legs. so if you lock them; the blood collects down there and your brain doesn't have enough causing you to faint.",
"Your arteries are lined with muscles that contract to help keep blood flowing through them. Your veins are not. The veins in your legs have leaflet valves that keep blood from flowing backward through them (like a ratchet, but with liquid) but nothing to keep the blood moving up. The flexing of your leg muscles helps keep the blood moving up against gravity back to the heart. The ability to lock out our legs is a useful ability that allows us to conserve energy while standing bipedally since it drastically reduces the amount of muscle activity necessary to stay upright (apes cannot to this and therefore are not comfortable on two legs for extended periods of time). However, that reduction in muscle activity means worse blood flow out of the legs, this reduces the amount of blood available to the brain. Throw in various factors including environment and health and that can cause you to pass out.\n\nI do lock out my legs when standing for the most part but occasionally slightly bend my knees and wiggle my toes to keep things flowing. It's gotten me through some long formations and inspections in the US Marines but what works for me may not work for you. \n\nEdit for poor thumb typing and formatting. ",
"Most people have covered the blood flow issue. You are also a lot less stable and more prone to injury with your knees locked. \n\nTry this, have you or a friend stand with knees locked. Go up behind the person with the locked knees and give a good push to the back of their knees. This won't hurt them, but it will throw them way off balance most of the time. Then try it without locked knees. \n\nAlso, if you stand with your knees locked and something hits the front of the knee... bye bye knee. At least with it not locked you have a bit of room to maneuver. ",
"I've never heard of this. I guess I've been standing wrong my whole life. ",
"Locking your knees doesn't effect whether to pass out or not. Yes, there is pooling of blood in your lower limbs since you are standing and not moving, but that happens regardless if your knees are locked or not. You can faint if you are dehydrated or low on blood sugar. \n\nWhy you shouldn't lock your knees is because if you do faint, you will fall over like a plank and probably hurt yourself. If your knees are not locked and you faint, your knees bend and you crumble downwards- a safer way to fall. ",
"This was a huge problem in the army. I remember one time Bush came for a brigade inspection so you had to stand in this field with your neutered weapon for like an entire day in the middle of North Carolina. So many people started dropping like flies and all the first sgts were getting super angry because it made them look stupid. \n\n",
"I passed out at a funeral for my brother's classmate's dad because I did this. Everyone thought that I was overcome with grief.",
"During my senior year of HS, a chick passed out during our choir concert. She was on the top row of the risers:( fell forward...thankfully she was ok. Her mom happened to be an EMT and was in the front row. ",
"Cuz it looks weird as fuck. Like you're too lazy to stand normal。",
"When I was in 2nd grade I was in CCD (like Sunday school for Catholics, except not on Sundays), we had a yearly thing called class mass. All it involved was our CCD class standing up on the altar for most of mass on Sunday. We were all dressed up and it was hot up there. I locked my legs standing there trying to be as proper as possible and I passed out. WHAM! I hit the stone altar hard, all while the priest is giving his homily and doesn't notice.\n\nWhat he DOES notice is my 6 ft 5 father leaping over a row of pews and rushing towards the altar. Priest thinks my dad is coming for him and hides behind the pulpit.\n\nAt the next year's class mass I got scolded by the nuns for wiggling my legs too much. I still can't grow hair on the scar on my chin from when I hit the floor to this day.",
"you will pass out and fall down... ouch",
"Orthopaedic surgeon here. None of these people know what they are taking about. Lock your knees all you want. ",
"As far as regular standing goes, I've no idea. However, I have been advised against it when standing for long periods of time (Chorus stuff) due to it being related to losing balance and passing out. Additionally, it's bad for athletic endeavors because your knee will take all of the energy, as opposed to your leg muscles, and could be compromised.",
"From a musculoskeletal perspective. Locking your legs allows you to 'hang' off your joint, and reduce muscle effort. But overtime this passive 'hanging' stretches the joint and it's ligaments, gradually causing joint laxity (leaving you more susceptable to sprains) or genu recurvatum deformity.",
"ELI5= its normal to have a little bend in your legs while you stand. You should feel like you're ready to jump rope at any second.",
"I had knee problems when I was a teenager, and when I went to a physical therapist, it turned out I had been locking my knees back so\\ that they were hyperextended 7 degrees through. I had to wear braces and do various exercises to restore the muscle tone that holds my legs straight - and even today, I have to be conscious of how I stand. Locking your knees can cause a lot of problems for the muscles in your lower half - and so can resting your legs on a coffee table, by the way. Sorry for the anecdote, but I was told at 14 that in another year without change, I wouldn't have been able to walk anymore.",
"What is locking your knees?",
"You are applying all your weight to a single joint/bone, if you are jumping from a high point you can end up breaking something. Same goes with weights training, legs always soft so the weight doesn't crush your joints.",
"I remember the many formations we'd spend hours in while I was in the Military. It never failed that a few people would drop like flies because they locked their knees. Their eyes roll back and just like that they're like a wet noodle",
"From what I understand (I'm no professional, nor do I have much experience in this area), locking your knees cuts off bloodflow. Until recently, I never had troubles with this. However, a few months ago, I fainted from standing like this, and nearly cracked my skull open on some steps.",
"because if i come kick you in the knee it would probably fuck you up",
"Lol I feel like some of these questions are posed by non-humans.",
"TIL I stand wrong...",
"I talked to a Physical Therapist friend once and asked this, I guess when you lock your joints, a lot of pressure is pushed over to tendons and joint structures. So, not only do you have the blood pooling effect that everybody is mentioning, but long term you can wear out joints and tendons. Pressure on these also is bad if you're sitting cross legged, and she mentioned a few others that I forget right now. Essentially, if you can use muscles to do something rather than relying on tendons and bone structures, use them because that's what there job is suppose to be.",
"TIL we aren't supposed to lock our knees when standing.",
"Who's stopping you from standing a little straighter? Stand however you like mate! :)",
"as said a thousand times, it cuts off blood flow, you'll pass out, seen it multiple times standing in formation for hours at a time.",
"My pilates instructor says you shouldn't lock your knees because you use your core muscles and glutes to hold yourself up so you're engaging your core. Otherwise your lower abdominals weaken and you'll end up out of alignment with a sore lower back.",
"I always heard this when I was little. So what did I do?\n\nEvery performance I was ever forced in, every time we had to stand for extended periods of time, I kept my legs locked and tried not to move at all because I wanted to see if I would really pass out. \n\nOver YEARS of trying, it never happened. Never came close. \n\nI do not believe in this myth. ",
"I didn't see it, but when I was in boot camp, some guy locked his knees, passed out, and promptly kissed the deck during our graduation ceremony.",
"Because you pass the fuck out from lack of blood circulation. Was in marching band during highschool, and they always heavily emphasized this when standing for large periods of time. During full retreat every single year, at least 2 people in the band would pass out from locking their knees. ",
"Restricts blood flow.\n\nIn the cadets we were taught that we shouldn't lock our knees and should slightly bend them, otherwise you might faint (something along those lines, I probably some important detail).",
"If you stand with your knee's locked, you can pass out from the lack of blood flow. I've had it happen before, it sucked.",
"You have plenty of answers about why you shouldn't lock your knees, so I'll tell a little story.\n\nIn college I had a professor that was obsessed with his students not locking their knees (drama professor, proper standing balance is important in theatre). He would often sneak up on students and gently push on the back of the knee with his foot. If the student had their knees locked they would stumble/fall as their balance shifted. If your knees were loose then your balance wouldn't change at all as your knees bent and you'd be annoyed, but still standing.\n\nI can't question his methods though, to this day I still don't lock my knees when standing around.",
"I have a life-long history of passing out hilariously from standing up too long (sometimes ten minutes is too long). Here are a few things that make absolutely no difference for me, tested many times:\n\nNot Locking knees.\n\nLocking knees. \n\nChanging breathing patterns in any way.\n\nWriggling toes. \n\nOutright jumping. \n\nIt was so bad that by highschool I was automatically allowed to go sit down/pass out quietly in private when we were having an assembly, no questions asked. I suspect there may be something wrong with my body.",
"dancer here, there's nothing completely wrong with it. In the Dance world knees that lock are a 'gift' and make your lines look stronger and more appealing. With the blood pooling, we don't get that because our legs are above our head half the time we dance",
"Can someone eli5 this thread please? I have know idea what \"lock our knees\" means",
"This thread made me more confused about the subject",
"as a girl who was in my high school choir competition will tell you, you will become light headed and pass out on the bleachers. but mainly i think it has to do with the fact that any time you use a muscle that's where the blood goes and your legs have really big muscles in them so the blood stays there and doesn't circulate as much. less circulation=lightheaded=passing out.",
"English is a lost art. ",
"While standing, having \"locked\" knees can pose a safety risk to the one standing, should they somehow become unconscious, or incapacitated. As said individual falls to the ground, there is a possibility for the person to just fall straight back, or especially forward, in a more rigid fashion, increasing the likelyhood of a head injury. Those with \"unlocked\" knees, seem to fall in a less rigid manner (they crumple), rather than falling like a solid object, hopefully decreasing the severity of any head injuries.\n\nTL;DR: Safety, Yo",
"On a skateboard, bending your knees allows your legs to act as shock absorbers, gives you a lower center of gravity (more stable), and gives a greater ability to shift your weight to steer.\n",
"It's because if the sky ever falls on you, you won't break your knees.",
"because the joint when locked in a straight position, cuts pinches off major veins, so blood and oxygen end up getting trapped below your knees. It messes up the circulation of oxygen in the bloodstream, and ends up leaving the brain with less oxygen, causing you to pass out. Also, because it causes shearing stress on the tendons and socket joint of the knee itself. I have major knee problems from locking my knees out of habbit when I was younger. I also have permanent dizziness as a result.",
"Fuck. Now I'm never going to be able to stand without wondering if I'm standing wrong. Fuck you reddit.",
"In the military, you have to stand at attention/parade rest for long periods of time. People who lock their knees tend to pass out, so they urge you not to do it.",
"I no longer remember how I normally stand. Do I lock my knees? Do I not? This thread is like engaging manual blinking.",
"Mechanical Engineering Explanation: If you lock your knees, your muscles are no longer suspending the joint, and thus any micro-vibrations will pass straight through your cartilage and will wear it down a lot more than if your muscles and tendons allowed for a more elastic network to dissipate these forces. Think wear and tear on a suspension bridge vs. fixed connection in a wind storm. \n",
"Thats one of the first and most important rule they teach you in bootcamp when learning how to stand at attention. DO NOT LOCK YOUR FUCKING KNEES. I saw two trainees lose there grill because of this. You pass the fuck out and most likely your teeth are going to mash on the pavement. ",
"I have personally never heard this. However, locking your knees in a position where there is stress on your legs means that the stress is on your joint rather than on your muscles.\n\nFor example, when you are performing a leg press or squat with weights, you are not supposed to lock the knees as it puts strain on the joints.",
"Here's some anecdotal stuff.\n\nAt my wedding, my father-in-law was in the wedding party meaning he was standing at the altar with us. It was a hot august day, outside, and we were all in suits. He ended up locking his knees. About 15 minutes in, he fell back, passing out and hitting his head on the ground. He had to be rushed to the hospital during our wedding ceremony.\n\nHe was in the army and was always told not to lock his knees, but he figured it would \"never happen to him.\" He's ok now, and we had 3 nurses in the audience, but it could've been really bad if he hit his head in a bad way.",
"When I was little we had to have these concerts where we'd stand and sing for a long time. One kid locked his knees while up there and passed out.",
"The blood in your legs gets recirculated through your body by the movement of your calves. Essentially every time you take a step you pump the blood that is pooling in your lower extremities back towards the heart. Gravity doesn't stop working inside your body, so this pumping is mandatory.\n\nSo if you're standing perfectly still, legs locked you won't have anywhere near the require blood flowing back to your heart.\n\nI'm not sure if the locking is the problem as much as the lack of movement, but it is definitely possible that in the leg-locked position the Vena-Cava is constricted more than otherwise.\n\nEDIT: typo at start.\n",
"When standing in military formation, it is advised not to do so due to the history of persons passing out during long time frames. Would you like to know why they pass out? They pass out not due to their locked limbs, but due to lack of air. Holidng their breath whilst puffing out their chest for formation/inspection seems like a good idea... at first. If your doing muster or standing watch, it doesnt hurt yourself to look sharp, but just remember to breathe. ",
"Because your best friend will walk behind you and tap the back of your knees making you fall flat on your face",
"This is just my opinion but if you lock your knees it makes it easier for someone to knock you over and I think it's bad for your knees",
"I guess this explains why some kids passed out in the 'morning openings' at the school. We had a small event like that in grade school every Friday that lasted about half an hour. Kids always had to stand there and it wasn't very uncommon for someone to pass out. It was usually the \"good kids\" too that took orders very seriously. ",
"They used to tell us not to lock your knees while standing when I was in grade school choir. One time we were preforming at a concert, and a girl in the back row fainted. Her knees were locked apparently, and she fell forward, taking out the three rows of singers below her. "
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hsw6g | What exactly are the limitations on childhood learning? | I'm thinking about this mostly in terms of homeschooling as I don't think there's a public or private school in existence that could do this, due to funding, teacher limitations, etc.
For example, would it be possible to introduce summation, differentiation and integration in say 3rd or 4th grade along with the other mathematical operations? Could the scientific method be taught in 1st or 2nd grade?
I guess the basis to the question is, why is the elementary, junior high, and high school curriculum designed the way it currently is? Could students learn more useful topics in a shorter period of time if it were redesigned, or is there some neurological / developmental reason that would prevent this from working? | askscience | http://www.reddit.com/r/askscience/comments/hsw6g/what_exactly_are_the_limitations_on_childhood/ | {
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"I feel qualified to answer this because I actually do Astrobiology education and have a masters in Education. \n\nThere are many schools that try different things. Some education researchers believe the only limit is time. IE if a student grasp a topic quickly you can teach them anything. There have been people who have graduated college at 12 years old because they picked it up so fast. Now I understand this is not the average person. Sadly our school systems are not designed for the average student, but for the below average student (no child left behind). \n\nAlso what comes into account is methods of teaching. It is being shown that through inquiry methods advanced science (physics, microbiology) can be taught to students in 2nd and 3rd grade. Really as long as students have the pre-requisites there may be no limit."
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3cqycl | how did donald trump end up with so much money? | He obviously inherited a good chunk, but I've heard all sorts of tales about how (and how well) he handled his money after that: "He would be worth more if he had just put his money in the stock market"; "He took advantage of the bankruptcy system"; "He made back his money by selling his name"; etc., but I don't have a clear picture of what exactly he did and whether he's an incompetent buffoon, a devilishly shrewd businessman, or something else. So I'd like to get a clear picture of how he got to where he is, so I know in what ratio I ought to be despising/mocking him. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3cqycl/eli5_how_did_donald_trump_end_up_with_so_much/ | {
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"he made a business of getting investors to pay for a building to be built, called trump hotel, tower, ect. he didnt use his own money that had been used up with a previous failure. so he goes to people a b and c, and asks each for a million bucks. b and c agree. he uses that million, tells a \"hey a, ive got 2 million bucks, give me another million and ill make a building worth 6 million\" so a goes along with it, because who doesnt want to double their money? then trump takes out a cut, builds the towers, and promises a b and c their money back, afte he gets tenants. if the building doesnt get tenants, then he files for bankruptcy, and loses a b and c's money, but he gets to keep the chunk he had taken out. rinse and repeat.\nedit: if he does get tenants for the building, then he says, \"A b and c, i have made you money, now i wish to put up another building, but i need 2 million each\" and he keeps going like this, making more money by taking out a cut each time. ",
"He's a decent businessman and a great salesman. And by far his most valuable asset is himself. He's been able to build and sell an image that makes other people want to buy his products and rent/buy his properties. \n\nIt's very hard to make a profit selling undifferentiated goods, it's easy if what you sell carries an advantage. If consumers are willing to pay 5% more for a Trump suit or to stay in a Trump hotel than go to an undifferentiated alternative, then that 5% is pure profit. \n\nIn business you make money by limiting supply, and Trump has a monopoly on the use of his name. And for good and bad, the Trump brand carries a lot of value in many markets. \n\nIt's the same basic reason why music starts and actors who know nothing about business are able to make money selling branded clothes and accessories. People pay more for the same things because of the brand they're associated with. ",
"He inherited a fortune from his father. Forbes points out that his net worth is likely half of what he claims. That means that if he'd stuck his inheritance in a mutual fund he'd be worth more today. He's a shit businessman.",
"I heard he protects the Trump name and owns another company named something else. If something he does is successful, its Trump enterprises all the way. When something starts failing, he 'sells' it to the other business, and the flawless Trump record remains 'successful'.\n\nThat, and he started with daddies 200 million. "
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1zfgyh | For depression and anxiety disorders, what is it in the brain that triggers the change in behaviour? | I am asking in the chemical or biological sense, when people suffering from depression or anxiety go "down" or have anxiety attacks, what is it in the brain that causes the degradation of their mental state?
Emotional responses are one thing but the symptoms aren't just that people feel down, they actually think more negatively about things, dream up impossibly bad scenarios and convince themselves that they must be true etc, causing themselves the emotional pain in the process.
I'm wondering if we know what causes this? | askscience | http://www.reddit.com/r/askscience/comments/1zfgyh/for_depression_and_anxiety_disorders_what_is_it/ | {
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"The one and only correct answer is: we don't know.\n\nSure, it looks like serotonin is involved. But it also looks like many other neurotransmitters are involved. And it doesn't stop there, because there are several brain regions and nuclei which show either reduced or enhanced activity during a depression. And it doesn't stop at your brain either, because even declines in your immune system functioning and other bodily functions have been documented. And that's just observational research. We haven't even come close to establishing any kind of causality.\n\nThat being said: you need to get yourself help. Posting this question on AskScience is *not* going to help you battle depression and/or anxiety disorders.\nFor that, you need assistance from a professional. \nAssistance meaning therapy, combined with medication if and when necessary. "
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1sf40e | Germany and France are next to one another yet have vastly different languages. Why is this? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1sf40e/germany_and_france_are_next_to_one_another_yet/ | {
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"Territory that we now call France was part of Roman republic (and later Roman empire) for centuries. Its previous Celtic-speaking population adopted Latin language which later developed into dialects of Vulgar Latins, called Romance languages, which included the ancestor of Old French and finally French. \n\nWhereas most of Germany were left unconquered by the Romans. This area was later inhabited by various Germanic (and to lesser extent Slavic) tribes. This is why the French speak languages descending from Vulgar Latin, where as the Germans speak languages from Germanic languages (and to lesser extent we have Sorbians in eastern Germany which speak a Slavic language).\n\nThere were indeed various migrations from area of modern-day Germany to France after the fall of Roman empire, most importantly the Visigoths, the Burgundians, and the Franks, from whom France took its name, but these \"barbarians\" migrants were absorbed into the existing, settled Gallo-Roman population and mostly adopted Romance languages. \n\nBy the time of Charlemagne, whose ancestors were Germanic Franks from modern-day Low Countries and western Germany, the Franks already started using Old French in addition of their Frankish languages. This shift further accelerated under his successors as Charlemagne's western Frankish realm (which consisted of most of Romance area) was separated from Charlemagne's eastern Frankish realm (which consisted of Germanic and Slavic areas).\n\nHaving said that we also have to consider the modern phenomenon of ethnic nationalism which equated citizenship with ethnolinguistic identity. There was indeed area in France whose population until recently spoke Germanic dialects, the Alsace-Lorraine, or in German Elsass-Lothringen in the east and Dutch-speaking area in South Flanders near English Channel. The Germanic languages in these area declined significantly following the rise of Nationalism in French revolution, where education in French and speaking in French were enforced, often very severely. This strict enforcement affected not only Germanic languages in France, but also non-French Romance languages such as Occitan and Provencal. The practice is known as *Vergonha* in Occitan.\n\nAlsace-Lorraine was conquered by the Germans from France in 1870 following Franco-Prussian war. After regaining the area after World War I, the French intensified their Francification in the area, and today Alsace-Lorraine is a French-speaking area. "
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87zvzl | how does ovulation work? what are 'safe days' and 'fertile days'? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/87zvzl/eli5_how_does_ovulation_work_what_are_safe_days/ | {
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"Fertile days are the ones just before, during and just after ovulation, about 3-5 days depending on your cycle. It's the time you're most likely to get pregnant. Ovulation is when one of your ovaries releases an egg to your uterus. Safe days are the ones you are less likely to get pregnant. The most safe days will be just before you menstruate. Be aware that you could possibly still get pregnant on safe days, it's just less likely. ",
"This video gives a bit of explanation as to what is happening when during your cycle... \n_URL_0_",
"If you don't want a kid, then you should probably use other more effective means of birth control such as condoms. Tracking your ovulation is fine if you're in a committed relationship and are prepared for what may happen if you track it wrong or the cycle is off for a month. "
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4phsh2 | At what point did different civilizations begin to build vertically? What are the earliest multi-story buildings? | It occurred to me the other day that creating a flight of stairs or a ladder is not a simple invention. At what point did humans go from having single story buildings (houses or otherwise) to having buildings be two or more stories? What did they use to get to the top? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4phsh2/at_what_point_did_different_civilizations_begin/ | {
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"Very early.\n\nThe cities Harappa and Mohenjo-Daro in the Indus Valley Civilization (which existed fro 3000 BC-1700 BC) which can now be found in modern-day Pakistan and northwest India were excavated to have several multi-storey buildings. \n\nAnd an interesting feature of the very early city of Çatalhöyük in modern Turkey which existed from 7500 BC to 5700 BC was that ladders from the ceiling were used to enter the houses instead of doorways. \n\n"
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qtijv | Did Greece's ancient significance to Western history influence early decisions to admit it to the EU/Eurozone? | Despite being the subject of Ottoman/Turkish control for nearly 500 years and subsequently lacking many modern Western European cultural, economic, and social institutions and shared experiences, it was admitted to the EU and Eurozone very early on. In light of its economic woes, was it admitted prematurely? Did its historical significance as the "birthplace of Western civilization" unduly influence European leaders to admit it to the EU when it may not have been ready? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/qtijv/did_greeces_ancient_significance_to_western/ | {
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"I would say that it was probably more to do with the fact that towards the end of WWII, the UK and the USA supported the Greek royal family and government against comunist and leftist military groups in the Greek civil war, and the western-backed government eventually established control. They then joined NATO and got money as part of the Marshall plan, so were closely related to other European nations that later made the EEC, later EU",
"*As a note, I'm going to use the term EU throughout, though technically EEC is accurate for much of the period discussed*.\n\nThe answer is no, though Greece did receive special political consideration:\n\n\nTo give you an historical sketch, Greece ascended to the EU in 1981, several decades before other eastern european states with similar economies did. \n\nThe process to join the EU is complicated, and a consists of a mix of legal and political barriers. For purposes of discussion, they involve:\n\n* Mandatory 'red line' issues, mainly relating to human rights complaince and legislative procedure. Essentially the ascending state needs to be compliant, or able to rapidly comply with all the conditions of EU membership (the [Four Freedoms](_URL_1_), human rights, resolution of political issues with other EU states, etc. \n* Legal and economic 'amber line' issues. The EU's commission, it's exceptionally assembled civil service, audits a prospective nation's economy and legal infrastructure for issues which may not be show-stoppers as red-line issues are, but which make membership complicated. \n* Political tussling. The political as opposed to administrative leaders of each EU state then examine the Commission's above work, and decide on whether to proceed. They can overrule the 'amber' issues, but not the red ones. \n* Implementation. The EU will organize a framework and timetable with both its existing member states, and the new applicant. Existing states can attach conditions to ascension, an example being the UK's arguing for a bar on polish migration for a number of years after Poland joined (normally Polish-EU citizens would automatically gain a right to immigrate to other EU states on ascension, but concerns over an influx led to a negotiated time-delay on this one particular right). \n\nGreece passed the red-line test, but failed the amber one. Commission officials officially recommended against ascension due to Greece's distance and political and economic underdevelopment compared to the rest of the EU.\n\nThe member states however disagreed, and overruled the commission. There was a **huge** amount of political wrangling over this, [for example here](_URL_2_), and there were widespread concerns over Greece's ability to integrate successfully with the EU.\n\nSo, greece got special treatment, but was it because of it's pedigry?\n\nI don't think so.\n\n* Greece had just emerged from a political dictatorship. A dictatorship is obviously utterly unacceptable to EU membership, and as with Portugal and Spain, NATO / EU interests were decidedly in favour of integrating them into a political structure that had proved astoundingly effective at preserving democracy and stability (the origins of the EU lie in the attempt to make ['war unthinkable'](_URL_0_) amongst its member states by shackling them together economically.) \n\n* It's application came a year after Turkey invaded Cyprus and led to Greece withdrawing from NATO as a result of inaction. Given that the cold war was raging, keeping Greece firmly in the Western / Capitalist sphere was undoubtedly a motivation amongst the EU states.\n\n* Having mentioned the Cold War, it might be a good idea to bring up the general aim of EU enlargement. Without getting into the politics of it (as a rule, EU members opposed to perceived centralisation favour enlargement, whilst integrationists oppose it) the EU's final size is all of geographic Europe minus Russia. Of course, because of the cold war the Eastern European states were out, and Turkey is a cultural issue that the EU has still not resolved. Switzerland and Norway also just don't want in (yet), so Greece was, at the time, a pretty logical move for expansion.\n\n\nSo those factors should hopefully make it clear that there were powerful EU, Cold War and NATO reasons for allowing Greece an exception.\n\nWhat about culture?\n\nGreece is Christian, capitalist and definitively European. Though it was under Ottoman control, it retained (and more interestingly, redeveloped) a powerful identity of its own. If you had to chalk modern Greece into a cultural class, European would come before any other word.\n\nIt's important to understand that this Greek identity is, romanticism aside, stridingly different from the classical greek one. From their tussles over reform of their language to their decidedly un-athenian government structures for much of the post-war era, Greece is not ancient greece. \n\nCultural issues don't usually play a favourable role in the EU. They serve as a political excluder as Turkey demonstrates, but given the uniqueness of each EU state's own culture, Greece's (and I would dispute this somewhat) role as father of Western thought would have little bearing on the Greece of now, other than to make clear to the EU that it is within the ambit of expansion (as Turkey is).\n\nSo I doubt it had anything to do with ascension. **Certainly** the Greek press and sympathetic journalists would probably have had a field day in the propaganda wars that were going on in between the Commission's rejection and the political organs overruling. But that doesn't at all mean they formed a substantive part of the decision making.\n\nOne last point: Greece's economic woes are more of an issue of the Euro, which was separate to membership. The Euro wasn't a serious proposal until several decades after Greece joined and by that point all EU economies were deemed competent enough for the monetary union (we can debate back and forth over the naysayers at the time, and whether they were prescient or just sceptical). \n\nA telling point is that if Greece was being pulled into the EU despite its economic inability, member states would have attached strings to its ascension in the same way that ascending Eastern European states did (remember Poland?) in the 2000s."
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3e1cpt | why isn't the white house flag at half staff following the tn shootings? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3e1cpt/eli5_why_isnt_the_white_house_flag_at_half_staff/ | {
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"short answer is it's unclear. They lowered after Fort Hood, but don't usually lower federally for soldiers killed in line of duty. \n\n_URL_0_"
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5ahxbr | why was the morse code discontinued? | It seems very versatile, not just for telegrams but for secret messaging and transmission of knowledge with just visuals. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ahxbr/eli5_why_was_the_morse_code_discontinued/ | {
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"Morse code became obsolete when people found ways to transmit voice over radio/wire. As for the \"secret\" messages - they are not really secret, since anyone who knows the Morse code can decode them. And there are easier, more secure way of sending secret information than Morse Code. For individuals, it isn't really worth the effort learning it (unless its your hobby or something).",
"Why don't we write on stone tablets instead of paper? Because the alternative is better.\n\nMorse was OK when it was literally the only option, but now we've got plenty of better ways to send a message, none of which require me to learn something special that I don't already know.\n\nFor a while, morse was still in use in situations where you couldn't get decent enough radio signal to get a message through, but with the advent of satellite communications even that usage is disappearing.\n\nIt's still used in certain fields - some radio amateurs use it (but probably because they can rather than because they need to), plus certain automated devices including some aircraft navigational beacons will report certain information using morse.",
"It *hasn't* been discontinued, and is alive and well in Ham Radio.\n\nIt's absolutely terrible for secrecy. Never do that. But for narrow bandwidth, great."
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da6rfb | Did Celtic cultures outside Gaul, Britain, and Ireland have druids too? | According to Wikipedia, Transylvanian Celtic religion may have influenced the practices of druids in other Celtic regions. But I'm not sure if these Transylvanian priests were quite the same thing as druids. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/da6rfb/did_celtic_cultures_outside_gaul_britain_and/ | {
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"The first problem there is that ,due to the popularity of \"Celtic\" romanticism and Celtic Revival, a lot of features are popularly attributed to all of Celtic peoples without necessarily being attested or verified in sources, either historical or archaeological Druidism isn't an exception to this rule.\n\nEven if, thanks to exploiting ancient and medieval sources as well archaeological data, we might have a relatively clearer perception of Druids, it still a fragmented image where various interpretation create important academic debates.\n\nIn Antiquity, Druidism is only mentioned by Greek or Roman authors as a Gaulish and British feature : never the word or an equivalent position is described for Celtiberians, Danubian Celts or Irish; it doesn't negate the possibility of their presence in these peoples, but the argument tends to revolve about the axiom of Druidism being pan-Celtic, which is largely unproven.These sources first identify druids in the late IIIrd century BCE but it's possible that they were known by Greek scholars as far as the Vth century, after centuries of contact with Mediterranean Celts in comparison with Pythagoricians. Did druids only appeared with the LaTenian period, however? This is the other bone of contention between historians arguing in favour of an earlier, proto-Celtic institution, and those arguing in favour of a Gaulish institution born out of the contact with Mediterranean peoples (trough trade or mercenariate) and the transformation of local polities in the VIth to Vth centuries BCE^(1).For the sake of transparency, I must say I rather agree with the latter and follows essentially this perspective in this post : even there, the existence of \"pre-Druids\" existing from the late Bronze Age, is still considered possible.\n\nThese Gaulish and British druids had an important set of responsibilities, ranging from organising religion to being philosopher, as well as scholars and judges.However we can still see a functional slip of Druids, still considered as seers in the Vth century, when *Uates* took over this role in the IInd; which possibly hints at the role of the aforementioned \"pre-Druids\", or even as sorcerers of sorts which would be essentially cast away later in Gaulish Druidism in favour of a more rationalist figure closer to a Greek philosopher or a theologian than a priest (bards and uates being unfortunately ignored by Caesar, hence a later mix up of Druids as seers, sacrificer and priests).In this perspective, contacts with Greeks since the VIth century, the Rhone trade road entering deep in Gaulish and Celtic heartlands, might have well played a role there, especially given the trope of Gaulish philhellenism (hellenic influence being obvious in regions closer to Massalia, as it appears in the oppidae of Ensérune or Entremont; but also further as demonstrated by the Vix Krater) new ideas colliding with old ones in the early Celtic states of the region, filling a social vacuum with the decline of Halstattian aristocracies in the VIth - Vth centuries; partly explaining the cultural rupture between Halstattian and Latenian cultures.Ancient Greek made comparisons with Druids and Pythagoricians, and the fortune of the latter in Greek Italy might provide something to the idea early Druidism could have been partly and indirectly inspired by Pythagore's disciples but as well by Orphic tendencies among Greeks, especially with the stress on metempsychosis. (Peoples closer to Mediterranean Sea are also the same that seem the less marked, if at all, by a Druidic influence; which would stress the indirect transmission and an original emergence of Druidism among Gauls).\n\nGaulish sanctuaries might be an interesting feature too on this regard : the appear, almost out of the left field, in the IVth and IIIrd centuries without known predecessors. While superficially Greek-like on the exterior, the interior is open-aired and both the sacred wood (*nemeton*) and the altar are close to each _URL_0_ would be tempting (and it is done, truth to be told) to associate this brand new religious materiality to Druidism : chronological correspondence isn't really perfect tough, and it would require new archaeological discoveries to be more decisive when it come to Britain (Britto-Roman temples, as Roman temples in Gaul, being quite distinct from the aforementioned sanctuaries)On the other hand, it was previously thought to be rather a northern Gaulish thing but equivalent had been found in southern Gaul too, namely in Le _URL_1_'s hard not to hypothesize a Druidic presence in Germania, where people share essentially the same culture than Gauls until the Ist century BCE, but there's a lack of historical and archaeological sources to propose something strong enough; although speculating about their presence there isn't really implausible; that the known Druidic annual council took place in Gaul (in the territory of Carnutes, believed to live in the center of Gaul) and the comparison with \"lay\" Gaulish council might indicate that neither British druids or their hypothesized Germanic colleagues took part in these.\n\nDruidic presence in Britain is nevertheless attested for the Antiquity trough Roman sources, which giving the important ties between Gaulish and British peoples is quite logical, as well as an increased presence pointed by Caesar since the IInd century (probably because Roman influence was detrimental to Druidic teaching even before the conquest). Welsh sources are too scarce to be really definitive, but could hint at a pre-Roman reality.Presence of druids in ancient Ireland, however, is a challenge : there's simply no mention of them for the period and only medieval texts which depict them as different figures than British or Gaulish counterparts : wizards, enchanters, brewers, sorcerers, or even quacks. Giving the relative isolation of Ireland, it might be possible that an equivalent of \"pre-Druids\" remained there as an archaic feature, possibly called druids by later chroniclers linking them to what they knew of Gaulish or British pagan religious figures.\n\nEventually, what we call Druidism from ancient sources about Gauls and Britons might have been only one of the religious (understood as an institutions) traditions of the various Celtic cultures, which could be compared only to what might have existed in Ireland as an isolated archaic survival; but not efficiently to Celtiberians or Danubian peoples due to the utter lack of historical and archaeological evidence.\n\nRegarding your second question : aforementioned contacts between Celts and Greeks don't seem to have taken place in Balkans, mostly because migrations to Middle Danube and Balkans took place only in the IIIrd century BCE; but also because contacts there took a more confrontational look with raiding expeditions. While druidic presence is possibly hinted at trough the *Drunemeton* of the Galatians, it might be due to a Gaulish influence rather than a local \"re-creation\" of Druidism (although Druids themselves aren't accounted for in Galatia, maybe due to an early and intense Hellenistic influence).It is only at this point that Celtic influence (either due to migration of Celtic or Celticized peoples; or Celticization trough trade or relations of local peoples) can really be pointed at in Transylvania, when Druidism is already attested in Gaul.\n\nThe (broken) source in the Wikipedia article seems to comes from Carl Wadman and Catherine Mason's *Encyclopedia of the European People;* where a lot of assumptions made about Druids (as being pre-Celtic, unmistakably seers, not taking part in fights, direct continuity between ancient and medieval Druids etc.) could benefit from actual sources, and some other are blatantly wrong (Caesar never mentioned Anglesey as a Druidic centre, neither Bibracte by the way). Both of the authors seems to be freelance writers of pop-history and, while I don't want to seem lacking respect to them as persons, you'd be better off with actual historians of Celtic peoples (*Druids : a very short introduction*, by Barry Cunliffe for instance even if you'll find he describes a much different perspective that the one in this post)\n\nWhoever put this source in the Wikipedia article, furthermore, *doesn't seem to have even actually read it,* as the author states that \"The Dacian priestly class may have emulated the Druids of the Celts\" (it's technically possible, but a direct Pythagorician or Orphic influence from Greeks is as if not more plausible) which you could recognize as the exact contrary of t*he Dacian priestly class may have influenced the* *druids* *of the Celts*\n\n\\- *The Celtic Gauls: Gods, Rites and Sanctuaries*; Jean-Louis Brunaux; 1988\n\n\\- *Les Druides - Des philosophes chez les Barbares*; Jean-Louis Brunaux; 2006\n\n\\- *The Druids*; Stuart Piggot; 1968\n\n(on a more Indo-Europeanist and Pan-Celticist take)\n\n\\- *Les Druides*; François Leroux, Christian Guyonvarc'h; 1985"
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fheeo5 | Through *The Odyssey*, it's a severe threat to social order should Penelope entertain lovers (as exemplified in the ominous tale of Agamemnon's return), yet Odysseus himself has a string of lovers (Circe, Calypso, possibly Nausicca); was he a special case or indicative of a cultural double standard? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/fheeo5/through_the_odyssey_its_a_severe_threat_to_social/ | {
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"I can perhaps add a few notes on the character, raise some complications, and offer some ideological background given to these distinctions in the Archaic period. \n\nPenelope is presented as a crafty, prudent, wise, loyal, yet also empathic wife (e.g. Hom. Od. 24.191-203) and this is her reputation also later, for instance in Apollodorus and Pausanias. Yet she is strangely remote from her family of origin (even her father plays no part in the Odyssey) and is explicitly contrasted with the sorceresses (Circe, Calypso) and other superhuman women, including Helen (Hom. Od. 4.219-235), and with the husband killer Klytaimnestra, all of whom exemplify normatively deviant forms of wife/womanhood. \n\nUnlike these women, Penelope is therefore a character designed to be an ideal in loyalty and decorum, in her weaving, her devotion to her husband's family, her production of a good son, and her crafty preservation of the household in her husband's absence. Her character therefore tells us about the idealising elite expectations for married women in the Archaic period, but little about their actual, average behaviour, which surely involved closer ties to their family of origin, especially in an extreme situation like the one the Odyssey explores. Looking beyond the idealisation, she is also, however, linked to Odysseus throughout the Odyssey by inverse similes, designed to undercut and enrich the portrayal of the ideal gender roles by pointing out their potential inverses.\n\nAs others have pointed out, the sexual politics of the Odyssey and its differentiation by gender does agree broadly with other normative texts (Xenophon's Oeconomicus, Plato's Laws, Demosthenes and Lysias Speeches involving family matters, some archaic poetry etc.), though they are largely from particularly restrictive Athens and later in date. In the Odyssey itself, having multiple lovers is a trait of bad or superhuman women and therefore certainly conceivable, but not normatively acceptable. What Odysseus does, sleeping with divine women, is however not a simple matter either: The Homeric Hymn to Aphrodite offers a different perspective on such relations, in that Anchises is weakened by his sexual encounter with a goddess, something Odysseus escapes, perhaps because these relations are not being presented as legitimate relations, but as exceptional relations meant to characterise the deviant women and the difference between divine and human experience rather than Odysseus.\n\nWhat is at work here more generally is a deep-rooted concern with Eros (“desire”), a primal force (Hes. Theog. 116-122) that has to be controlled by culture, but causes failures of such control in many a form. This force is imagined in the Archaic period to have taken form for mankind via Pandora, who turns mankind into a race with two sexes, ending the golden age (Hes. Op. 57-92; Theog. 590-613) and making man dependent on women for offspring. This ideologically „explains“ and „justifies“ the difference in social space accorded women in sexual matters, as they hence have to be controlled (by rites of passage like marriage) as sources of evil. Lack of such control causes most of the messes Greek tragedy explores.\n\n**Some reading:**\n\nSkinner, Marilyn B., *Sexuality in Greek and Roman Culture*, London 2013.\n\nWohl, Victoria J., “Standing by the Stathmos: The Creation of sexual Ideology in the ‘Odyssey’”, in: *Arethusa* 26:1 (1993), 19-50.\n\nFoley, Helene P., “’Reverse similes’ and sex roles in the Odyssey”, in: *Arethusa* 11 (1978), 7-26.",
"It is not quite an identical question (and if you have followup questions, let me know), but you may be interested in the answers to [this similar question](_URL_0_) by u/sunagainstgold (especially considering the ways in which a mortal/divine pairing could fall outside the normal rules of marriage), u/AristaAchaion, and me.",
"The short answer is that it was a big, BIG double standard.\n\nAncient Greeks were extremely misogynistic by modern standards, and even by ancient standards. Women weren’t allowed out of the home alone, and they were expected to get married young, spin a lot of wool, and die in childbirth in their early twenties.\n\nA good source for this is “On the Murder of Eratosthenes,” a speech by Lysias. You can get a good sense of what was allowed and not allowed for women in Athens.\n\nFor the Greeks, to penetrate was to be a man. Womanhood was defined by chastity to better facilitate transfer of property via inheritance and manhood was expressed by having sex with women, having sex with men, having sex with boys, and stabbing people. All forms of penetration.\n\nRe: Agamemnon, Aeschylus inserts a metaphor early on in the work which implies that Agamemnon’s real crime wasn’t taking Cassandra as a slave, but rather damaging the household. When he first returns, Clytemnestra has him tread over some tapestries from the palace to symbolically re-create his sacrifice of Iphigenia to Artemis. Bringing Cassandra back was an insult to Clytemnestra, but not beyond the realm of normal. Killing Iphigenia wasn’t a crime because he killed his daughter, but because he diminished the worth of the household. Clytemnestra taking Aegisthus as a lover, however, was a good enough reason for Orestes to murder her. In short, Agamemnon was not killed only for his adultery.\n\nRe: Penelope and Odysseus, Odysseus cheating on Penelope is not culturally as bad as Penelope cheating on Odysseus simply because Penelope was considered a part of Odysseus’ household like Iphigenia was hers. The suitors had to die because they were trying to deprive Odysseus of his household. The women of the house who slept with the suitors had to die for betraying the house, but it was extra bad because due to the above mentioned double standard, their act was also considered sexually immoral.\n\ntl;dr: the rules of sexual morality were really different for men and women in Ancient Greece."
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1q0sny | why the king of hearts (also known as the suicide king), is more often than not, depicted having a sword through his head | [Here's](_URL_0_) an example of 4 seperate card decks with the suicide king, including the King of Hearts from both The Simpson's and Futurama's decks (Although in the Simpsons deck, The jack of hearts is responsible for the barrel of the gun).
Does anyone know why this is a recurring thing? Just Google image search "King of Hearts" and you will see many different decks with this happening.
Maybe I will have to try /r/askhistory. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1q0sny/eli5_why_the_king_of_hearts_also_known_as_the/ | {
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"In the 15th century, the French had given names to each of the kings: the King of Hearts was King Charles, AKA Charlamagne.\n\nHowever, him stabbing himself in the head originates after this. Only references I can find is that the deck images in use now are French designs, easier to copy with a block than the more elaborate German designs which were popular previously.\n\nThat said, I can't find any references to why he is stabbing himself, or why there are one-eyed Jacks either. Most likely, they just couldn't fit the sword in vertically and they made it look much like he was swinging it.",
"I don't know how true this is, but I heard the suicide kind isn't actually stabbing himself. It is actually the knife of the Queen of Spades. The evidence is in the sleeves and the way each card is facing. In truth, he is actually being murdered. \n\nCheckout this site. The theory is well-explained here.\n_URL_0_",
"No proof or source, but I've always understood it that he was drawing or preparing to swing the sword",
"He wants to die because he can't grow a sweet 'stache like his bros.",
"The sword is behind his head, like he is about to swing it. It would be pretty ineffective to kill yourself by trying to stab through the side of your head.\n\nSuicide king is just a nickname from how it appears, and many people who make novelty deads keep up with the theme.",
"I'm not sure about the origins, but I've always understood the suits to represent different classes of society, or lifestyle motivations? God now that I'm typing it I realize my ideas are totally fuzzy. Good question.",
"According to [this source](_URL_0_), there is no story or history behind the design; it looks like it was just a series of adjustments made by publishers over the years to cram as much of the original 16th century design into the smaller and smaller cards...",
"from the research i have done on traditional playing cards, i would say that the answer to this question is lost in history. from a time when playing cards were considered to be a luxury for the upper class, to when they become more readily available in part by advances in printmaking technology, the reproductions had slowly but surely become significantly rendered to the point where such symbolism delineated from its original intent. there are some sources which tell of Charlamagne as the king of hearts, but the descriptors of each suit are too vague to be certain. ",
"In your example the latter two were developed way after the \"phrase\" suicide king\" was in place so as a novelty deck are just playing off the pre-existing lore of the card. \n\nwhile the [King of Spades](_URL_1_) and[ King of Clubs](_URL_0_) are the same holding a sword vertically the [King of Diamonds](_URL_2_) has an axe behind him (though no fancy name)\n\nthe King of hearts is also holding a knife/sword but *behind* his head like he's about to swing it. and i think that's the end of it there. 4 kings 3 different poses, and since wherever they originate became ***the*** style for cards it's represented everywhere. \n\nat some point someone looked at that and said \"hey it looks like he's putting a knife in his own head. after which i'm sure tales were made up of why it was like that and theories etc when really the original artist just wanted to mix it up in the graphics. ",
"As a related ELI5, I'm having trouble finding online who is responsible for the most recognizable (at least in america) playing card royal faces? For example, both kings in OP's link look pretty much the same, with minor differences- the style of dress looks like it could be 18th century perhaps? \n\nI've found that 16th century Parisians are responsible for aesthetic we're most familiar with today, but who first gave us the zoomed-in portrait of the King, Queen and Jack, with their curly hair and heavy mascara, that are well-known today? Was it just some designer at Bicycle? ",
"Also, why is he the only king without a [mustache](_URL_0_)?",
"I always thought the sword was just going behind his head. ",
"He doesn't. It's behind his head. The reason it's behind his head is that he was holding it up in the original drawings, while the other kings had their weapons vertical.\n\nThe modern English design (double sided Monarchs) is based on the French design from the 15-16th century. In the original drawings, the red cards were holding axes and the black ones had swords. \n\nLater copies were more distorted. Within a hundred years (especially in England) the king was holding the axe behind his head, and by the 19th century, the King's Axe been made to look like the hilt of a sword by shoddy copy-artists. The phrase \"suicide king\" came from people who looked at the design afterwards.\n\nThe modern design is the double-sided English design from as recent as the 19th century. The earlier English designs (very similar, but dating back to the 16th century) were single sided. \n\n*edit:I looked up the names. Thomas De La Rue, a printing pioneer, used his fancy printing to make the shoddy copy designs much more intricate. It seems most of the 19th century designs are specifically a ripoff of HIS much fancier ripoffs of earlier crap. Modern designs ripoff the company Reynolds, who printed the first double ended design in 1860, which was about 30-40 years after the single-sided De La Rue versions became popular. There wasn't much intellectual property law back then. Also, pictures!*\n\n\n\n\n_URL_1_\n\n\nHere you can see an example of a shoddy copy that caused confusion.\n\n_URL_0_\n\nGoogle *Rouen playing cards* and you can find more on the history of the design.\n\n\n",
"I'm a bit confused. I always understood/assumed that 'suicide' was more or less a nickname for a card, but I though it was in reference to the orientation of the blade to the head (blade facing head→suicide 【card】). So to me the King of Diamonds is also a suicide king. Was I the only one taught this?",
"Offtopic but interesting .. King of hearts is the only king without a mustache too",
"As person from east german, i can only laugh about the french design!\nReally cards look like this:\n\n[Altenburger Blatt](_URL_1_)\n\n[Old Design, more Pics](_URL_0_)\n\nall fun and easy :D",
"/u/blockplanner already explained this perfectly, but here's on article on _URL_0_ (they sell lots and lots of playing cards) that covers the same thing.\n\n[_URL_1_](_URL_2_)\n",
"I do know that the King of Clubs and King of Diamonds are called the Kissing Kings cause when you open up a new deck they are facing each other in the standard order.\n\nI'm guessing that the real answer is probably that there are only so many ways to draw a King in a different pose so that you can easily tell them apart quickly and the King of Hearts ended up in that funky position.",
"All this talk of swords through heads makes me think of Finland's coat of arms. _URL_0_\n_URL_1_",
"It's because he's married to the Queen of Hearts. Imagine the implications of that and you might want to kill yourself too.",
"I believe the ending of G Gundam explains it best. Spoilers, obviously.\n\n_URL_0_"
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423mqh | For your average Russian serf around the time of Catherine II, would joining the army be a step up in life? | From my understanding life as a serf in Imperial Russia was sorta shit, being sort of close to chattel slavery in many ways. So I was wondering if joining the Russian army was an upgrade in life quality at all? Was it a small step up the social ladder? Was the notoriously draconian life of the Russian army any worse than life as a serf? (when you weren't in battle that is) | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/423mqh/for_your_average_russian_serf_around_the_time_of/ | {
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"Modified from an [earlier answer](_URL_0_) \n\nMilitary service in the Petrine army and its successors was very much a mixed bag. One of Peter I's innovations, and one that made Russia's military unique up through the Napoleonic Wars was that he sought to establish a large, permanent force structure that made the Army a major institution within the Russian state. This meant that recruiting for the military embraced both volunteerism and increasingly a type of conscription or blood tax imposed upon peasant communities, the largest source of manpower reserve the Russia state possessed. The choice of recruits for this military poll-tax often fell upon the elders of the serf community, so these elders would often designate certain individuals, often those outside his immediate family, as the ones destined for military service. The Russian Army was also atypical in terms of the length of service, initially life, but limited to 25 years in 1793 and were garrisoned away from their native villages to discourage desertion. \n\nThe typical serf-recruit drafted would have a funeral service in his community before he mustered to his regiment. This funeral service was quite deceptive from the position of the twenty-first century and it is dangerous to take the idea of a funeral for the living at face value. Firstly, given the size of the empire, the limited transportation infrastructure, and the tactic of stationing the formations away from where they were recruited, it was highly unlikely a soldier could ever return home to his native village. Occasionally a soldier would be able to get a request granted for extended leave to return home, but regimental commanders usually granted such requests after receiving a bribe or other sort of inducement. Secondly, entering into the army meant leaving one's native estate (*soslovie*) and entering into a new *soslovie* class. The *soslovie* table of ranks in the eighteenth century was not as hardened and defined as it would become in the nineteenth, but military men, even lowly infantry men, were in a separate social estate set up for military service. This estate status was inheritable and was in evidence in many of the garrison towns that serviced the Russian state. It's important to remember that garrison duty was much more the typical life of a soldier than one of constant battles and garrison life became one of the focal points of a soldier's new life. Although there were restrictions upon soldiers' ability to marry, garrison life could make the regiments' authorities more amenable to granting permission. The children of soldier's wives could enter into garrison schools, first founded in 1721, that fast tracked young boys for military service. Similarly, off duty soldiers were legally allowed to practice a trade and if they were allowed to muster out, such individuals often became tradesmen. Those soldiers though who did not learn a trade or were otherwise incapacitated by injuries acquired during service, were often less fortunate. Some of these individuals returned to their birth communities as free peasants, but there was little role for them in their home towns. The state itself tried to correct this problem in the late eighteenth century by establishing military colonies in the southern portions of the empire, but as with many attempts to ameliorate the lives of older veterans, such efforts were often quite anemic. But it is also worth keeping in mind that the first priority for tsarist military organization was to create an effective and large fighting force, the needs of veterans was often subordinate to this need. The estate system imparted to the Russian army a much greater and cohesive institutional character than many of its contemporaries and the long-term service helped add to the Russian military estate as a somewhat distinct class in Russian society. \n\nHowever, just because the Russian armed forces were a special military estate does not mean that the tsarist state looked fondly upon them. Pay was very much in arrears and quite meager as many general and officers felt that the troops in garrison would spend it on drink and other surly pursuits. Discipline was very rough and corporal punishment was the norm. Cooking the rations of food provided was usually left up to the soldiers themselves, who broke up into small groups called *artel* usually run by a corporal elected by the ranks. The *artel* would organize supplements of vegetables and meat to the rations of bread, rye, or barley the commissaries provided. The organization of these supplemental foodstuffs led to collective sharing of excess pay, gambling windfalls, plunder, or other forms of currency and the *artels* acted as form of a bank for the regiment. This system created a degree of self-sufficiency within the Russian army and was something many foreign commentators observed that the Russian rank and file had an amazing recuperative ability and ability to march great distances in good order. \n\nThat said, there are also a lot of overlap between the life of the average Russian soldier and a number of his European contemporaries. Corporal punishment was quite the norm in most European armies at this time and low pay, or any pay, was a common complaint of soldiers regardless of which state they served. One of the common tropes of European veterans' accounts was that outside of those few who learned a trade, the civilian world had little use for the skills necessary for a soldier. The relative inaccessibility of sources on the Russian army, both because of the language barrier and the administrative poverty of the imperial Russian bureaucracy left a relatively small archival base, ensured that demi-Orientalist depictions of the Russian army by those who fought it have remained relatively unchallenged in a lot of popular literature such as John Elting's *Swords Around a Throne*, whose section on the Russian army is especially poor. The Russian army was in many respects the equal of its contemporaries and in some ways, their superior. The Russian artillery arm started strong under Shuvalov's reforms of the 1740s and remained typically much stronger than its European counterparts. The institution was able to promote individuals like Suvorov whom was just as capable a general as any in Western Europe. The hypothetical serf recruit entered into an institution that reflected the unique conditions of the Russian empire, but shared a lot of experiences in common (low pay, corporal punishment, boredom of garrison life, etc.) with his contemporaries. \n\n*Sources*\n\nDuffy, Christopher. *Russia's Military Way to the West: Origins and Nature of Russian Military Power, 1700-1800*. London: Routledge & Kegan Paul, 1981. \n\nKeep, John L. H. *Soldiers of the Tsar: Army and Society in Russia, 1462-1874*. Oxford: Clarendon Press, 1985. \n\nWirtschafter, Elise Kimerling.*From Serf to Russian Soldier*. Princeton, N.J.: Princeton University Press, 1990. "
]
} | [] | [] | [
[
"https://www.reddit.com/r/AskHistorians/comments/352yj8/im_a_young_serf_from_near_moscow_at_the_end_of/"
]
] |
|
1qplad | why do the vast majority of government websites look old and outdated? | Adding on to this question, since their design was funded in the first place, why aren't they updated? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1qplad/eli5_why_do_the_vast_majority_of_government/ | {
"a_id": [
"cdf5ku1",
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"Changes in design require new funding. Web development for the government doesn't run cheap - you have tons of regulation that has to be dealt with in addition to normal development.\n\nThey will probably at minimum need to have a Project Manager (100-150K salary), Frontend Web Developer (65-100K salary), Backend Developer (80-120K salary), and QA Engineer (65-90K Salary). Chances are there would be two to three Web Developers, two QA engineers, and maybe two Backend Developers if at all possible. That's my ideal web dev team for something that has to be robust. Sometimes you can get front and backend together, but realistically they should be separate.\n\nSo to update that website, there has to be enough demand and need for updated visuals/functionality for the Department to request the funds, and for Congress to approve those funds. Based on the minimum possible salaries, you're looking at close to 500K+ *per year* to get that website redone.\n\nLikely a lot of government websites don't see the levels of traffic necessary to make such a decision.",
"Government websites are not usually created by government employees but government contractors. These contractors participate in the bid process where the choice is based on two categories. 1) Cheapest bid, 2) Most documentation.\n\nThe project managers have to provide reams of data and scope documents explaining the process, risks involved, how the site will function, etc. It would seem logical to map out everything before you start, so you will know what it will cost and the time it would take. Unfortunately, predicting how long the process will take, resources used, and potential risks is not such an exact science. Also, creating anything innovative requires trial and error and quick thinking. This type of development is very hard to predict. Government employees are not known for taking any risks, so they want to know their ass is covered.\n\nSo contractors promise very vanilla solutions with the least risk (which are usually outdated), so that they can get through the bid process to get the job in the first place. \n\nIf contractors were hired to do the job without having to EXACTLY predict cost and time before you start, then they might have the freedom to develop something more cutting edge. In the corporate world, there is project management and design principals to predict costs, but it does not deter from innovation because they are not competing.\n"
]
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[],
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|
no118 | the third prong on an electrical plug | I know it's called a ground plug, and I know that it's a safety measure, but beyond that I don't know why it's there and why it's better to have one. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/no118/eli5_the_third_prong_on_an_electrical_plug/ | {
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"I took this from my physics class (15 years old) what it does, assuming their was a fault like an opencircuit and the resistance sky rockets, then you were to touch it your body has less resistance than the open circuit so you get electrocuted, but the Earth wire has a resistance less than you so it flows through there, I'm guessing it has a higher resistance than the wires though. Correct me if I am wrong. ",
"When you touch 2 wires together this creates a short circuit. A short circuit causes the electricity to flow real fast until a fuse or circuit breaker interrupts the flow. A ground is an \"escape\" for the excess electricity giving it a path to escape.\n\nIf a electronic or appliance develops an internal short circuit, this has the potential to shock you while you're using it. If the appliance is grounded, the excess electricity escapes through the ground.\n\nElectricity follow the path of least resistance, which is why a ground works, it lets is escape and disappate into the earth or your cars frame for example.",
"I usually refer people to this link which is funny, simple, and easy to read.\n\n_URL_0_",
"I took this from my physics class (15 years old) what it does, assuming their was a fault like an opencircuit and the resistance sky rockets, then you were to touch it your body has less resistance than the open circuit so you get electrocuted, but the Earth wire has a resistance less than you so it flows through there, I'm guessing it has a higher resistance than the wires though. Correct me if I am wrong. ",
"When you touch 2 wires together this creates a short circuit. A short circuit causes the electricity to flow real fast until a fuse or circuit breaker interrupts the flow. A ground is an \"escape\" for the excess electricity giving it a path to escape.\n\nIf a electronic or appliance develops an internal short circuit, this has the potential to shock you while you're using it. If the appliance is grounded, the excess electricity escapes through the ground.\n\nElectricity follow the path of least resistance, which is why a ground works, it lets is escape and disappate into the earth or your cars frame for example.",
"I usually refer people to this link which is funny, simple, and easy to read.\n\n_URL_0_"
]
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[],
[],
[
"http://amasci.com/amateur/whygnd.html"
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[],
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[
"http://amasci.com/amateur/whygnd.html"
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|
3rlrwl | Why don't vehicle exhaust pipes have some kind of CO2 and CO scrubbers like what spacecrafts have? | I tagged this as chemistry, but I'm not sure if that's an appropriate tag. | askscience | https://www.reddit.com/r/askscience/comments/3rlrwl/why_dont_vehicle_exhaust_pipes_have_some_kind_of/ | {
"a_id": [
"cwpnahq"
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"score": [
6
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"text": [
"Money mostly. We definitely have technologies that can scrub CO2 out of exhaust but they are either going to require constantly replacing some kind of absorbing media or a large amount of energy to convert the CO2 into something usable (like oxygen or a new fuel like methanol). Both of these strategies require a significant amount of money to implement and run, as well as being relatively bulky and likely a decent hit on gas mileage for the vehicle. If carbon taxes and offsets became a universal thing then it might make sense, or more people would just use electric cars and consolidate the CO2 capture at the power plant making the initial energy."
]
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[]
] |
|
j2grc | can someone explain stimulus package (like i'm 5)? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/j2grc/can_someone_explain_stimulus_package_like_im_5/ | {
"a_id": [
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"text": [
"Governments pay for projects, (like new highways or theatres,) so that more people can have jobs.\n\nThen more people will have money to spend, which will make more jobs for other people, (like shoemakers and dentists,) and soon enough people will be spending money and the government can start collecting saving tax money for the next economic downturn."
]
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[]
] |
||
1vgats | how is a spacecraft going to land on a meteor | I have been hearing a lot lately about new space probes landing on meteors. How is it possible that something that is moving so much faster than a planet and is also of a much smaller size can have any sort of gravitational pull for a probe to land on it. Some of the terminology I'm using is definitely off also. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vgats/eli5_how_is_a_spacecraft_going_to_land_on_a_meteor/ | {
"a_id": [
"cery3xa",
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2
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"text": [
"There doesn't have to be significant gravitational pull - the probe will essentially fly up alongside and match velocities so that it ends up touching the meteor. This is very similar to a spacecraft docking at the space station.",
"The exact same way we land on the moon or dock with the ISS. \nmoon (around the earth) = 3680 km per hour.\nEarth (around the sun) 107,300 km/h.\nSpace shuttle (at max vel) 28,003 km/h.\nIts all relative to the point of observation. \nIf the moon is flying around the earth at 3680 km an hour you slowly accelerate and move into its trajectory. Then it will be like you are both standing still. \n\nThink about the relative position of things. The earth is moving 107,300 km/h around the sun. Guess what ? So are you!!!! \nIf you think in terms of the universe we are moving WAY faster than that, spining around the galaxy, even faster with the milky way expanding outwards with the universe expansion. "
]
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[],
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] |
|
329x7a | what happens when we get "butterflys" in our stomach? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/329x7a/eli5_what_happens_when_we_get_butterflys_in_our/ | {
"a_id": [
"cq9966e"
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"score": [
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"text": [
"When you're nervous, your body floods with adrenaline. It's known as the fight-or-flight response as your body gets ready to react whatever way it needs to a danger. \n\nOne of the things that happens is your body reduces blood flow to nonessential organs and increases the blood flow to your muscles. For the short time you're likely to be in danger, your stomach is nonessential and the sudden reduction in blood flow and the consequent reduction in digestion is what you're feeling as 'butterflies'."
]
} | [] | [] | [
[]
] |
||
3ep5rc | why do extreme temperatures make me lethargic? | My AC is been out for a couple of days and its 100 degrees out. All I wanna do is loaf around. Same when its really cold. What up with that? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3ep5rc/eli5_why_do_extreme_temperatures_make_me_lethargic/ | {
"a_id": [
"cth1vjq"
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"score": [
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"text": [
"It takes a lot of energy for your body to either heat itself up or cool itself down. Leaves less energy for things like exercise... which will in turn only heat you up further. Shivering when you're cold is a way for your body to generate heat by using your muscles. High temperatures cause considerable increases in your heart rate and respiration - to circulate your blood from your core to the surface where it can expel heat. "
]
} | [] | [] | [
[]
] |
|
9vohww | why are fertility rates decreasing? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9vohww/eli5_why_are_fertility_rates_decreasing/ | {
"a_id": [
"e9dv7g3",
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"score": [
5,
2
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"text": [
"People are having less babies. Infant mortality dropped, women have other things to do than just parent, we have birth control. We can control when we get pregnant, and we don't need large families the way we use to.\n\nFertility rates aren't decreasing in a Handsmaid Tale way. We have a bunch of techniques for getting pregnant.",
"Mainly due to a lack of interest in making babies combined with good technological means of getting sexual gratification without making babies (condoms, the pill, ect)."
]
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[],
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|
1wwcvf | how do they show events that have not happened yet on t.v.? (ads for the opening ceremonies in sochi) | I was watching a commercial for the Olympics in Sochi that Start on Thursday and they had footage from the opening ceremonies like the torch being lit and countries walking in the stadium and being introduced. How do they do that if these events have not happened yet? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1wwcvf/eli5how_do_they_show_events_that_have_not/ | {
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"text": [
"That's footage from past Winter Olympics, not Sochi. ",
"It's footage from past Olympics, or footage taken from dress rehearsals, etc.",
"Sometimes they show archived footage from previous events. Sometimes they travel through time."
]
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[],
[],
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|
2t7aty | Can cancer spread through transfusion? | So let's say someone with cancer ( and doesn't know) donated blood. If the cancer had metastasized, could it then spread to the receiver? | askscience | http://www.reddit.com/r/askscience/comments/2t7aty/can_cancer_spread_through_transfusion/ | {
"a_id": [
"cnwshrm"
],
"score": [
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"text": [
"Its very unlikely. The cancer cells aren't cells of your own body, so your immune system will attack them. \n\nHowever there are some exceptions. If the cancer cells can make their way to an immunological privileged site (places where swelling is counterproductive and your immune system cannot reach... like eyes and testes), it can potentially seed and grow into a tumor. Also, if you had a compromised immune system, its very possible for cancer to \"seed\" itself in some nook and start growing. Essentially, if you are immunocompromised enough to recieve an organ transplant, you will be immunocompromised enough to get cancer from a transfusion.\n\n"
]
} | [] | [] | [
[]
] |
|
49s9tr | when did wearing the jersey of your favorite sports team become popular, and why? | Edit: I should have been more clear, I meant why as in why did it become popular. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/49s9tr/eli5_when_did_wearing_the_jersey_of_your_favorite/ | {
"a_id": [
"d0uh4o0"
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"score": [
2
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"text": [
"Showing support for your team has been a thing for a long time. I don't think that's changed appreciably in the last several decades.\n\nWhat has changed has been the availability of jerseys and the acceptability of wearing them in public. We've spent the last 50-60 years getting less formal & less rigid about dress codes in general.\n\nThe rise of hip hop music/fashion has probably also contributed a fair bit."
]
} | [] | [] | [
[]
] |
|
s66oz | How much of an image can you build of a person from simply examing their brain? | If you only had access to a random individual's brain, how much information could you gather from it, in terms of personality, appearance, race, gender, etc
This would be without looking at their genes though. | askscience | http://www.reddit.com/r/askscience/comments/s66oz/how_much_of_an_image_can_you_build_of_a_person/ | {
"a_id": [
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"text": [
"Not sure if this is allowed in the limits of your hypothetical experiment but if you put said person in an MRI and started doing [fMRI imaging of their brain](_URL_0_) in response to carefully thought out statements or words put to them you might well be able to figure out their gender and possibly ethnic background among other points -without seeing or hearing them yourself - by how strongly they react and in which part of the brain.\n\nDespite my tag my knowledge of fMRI is a bit weak so hopefully someone can expand on this.",
"If you just mean a brain in a jar that you could but in an MRI machine or CT scanner, then maybe some. The most helpful would be if the individual had a disease that affected the anatomy such as syphilis or Korsakoff's, or localized brain trauma; then you could make some inferences based on common symptoms associated with those diseases/injuries. \n\nYou might be able to get both gender and age based on the amounts of gray matter and white matter ([1](_URL_2_), [2](_URL_0_)). If you knew age, you might be able to get gender since rate of reduction of certain brain regions with age is thought to differ by gender (assuming we are talking about adult brains here). If you knew the gender, there's a study that claims that amount of gray matter in certain areas correlates with IQ and this differs by gender ([source](_URL_1_)). I'm sure there are tons of other studies that have looked at correlations between behavior and amount of gray/white matter; however, I don't know what the current thoughts are on which of those studies are any good =) If anyone would like to step in here, I'd like to know."
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/Fmri"
],
[
"http://cercor.oxfordjournals.org/content/18/12/2920.short",
"http://www.sciencedirect.com/science/article/pii/S1053811904006822",
"http://www.sciencedirect.com/science/article/pii/S105381190500145X"
]
] |
|
6kl2hr | is there no discernable brain activity that would allow us to read what a person is thinking? | If not, how come? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6kl2hr/eli5_is_there_no_discernable_brain_activity_that/ | {
"a_id": [
"djmwjxi"
],
"score": [
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"text": [
"We can detect which parts of the brain are lighting up, if the person is in an MRI, but not what memories, words, or images they are actually picturing. Brains are mindboggingly complex, and there is no one spot responsible for every word, image, or thought. If I think of a dog, it's not going to light up my brain the same way as when YOU think of a dog. It will even be different if I think of a different dog."
]
} | [] | [] | [
[]
] |
|
a1t3s9 | Does muscular atrophy cause muscle memory/acquired skills to decay? | Quick examples to elaborate:
If a pianist experienced muscular atrophy, would his well-honed fundamental skills and/or ability to play specific pieces decline? (Assuming the decline in his strength and stamina are not impactful on his ability to play)
If a baseball player experienced muscular atrophy, would his learned swinging and pitching technique decline? (Again assuming the decline in his strength and stamina do not affect his technique) | askscience | https://www.reddit.com/r/askscience/comments/a1t3s9/does_muscular_atrophy_cause_muscle_memoryacquired/ | {
"a_id": [
"eass42k",
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"text": [
"It likely depends on the cause of the atrophy. “Muscle” memory is actually a neurological phenomenon - a pathway worn into the brain from repetition. It should theoretically be retained unless the atrophy is neurologic (loss of its nerve supply will cause a muscle to atrophy) or possibly metabolic and organism wide (things like diffuse muscle loss from severe illness or starvation that could impact systems other than muscle). ",
"Okay there are a couple of concepts to deconstruct here, so do be patient with me.\n\nMuscle memory and muscle atrophy belong to two separate boxes, medically speaking.\n\nMuscle memory, unlike how the name sounds, actually happens within your brain where the areas affecting movement and coordination learn and fine-tune themselves upon repeated exposure. This is why beginner pianist can't play anything, but give them 30min playing the same thing over and over again and they will eventually learn it. Your brain forms muscle memory by making new links between brain cells (aka synaptogenesis). The motor areas within your brain proper are heavily utilised when you first perform the action, and with repeated exposure, your cerebellum then takes over. When your cerebellum takes over, one can say that muscle memory has truly 'formed'. \n\nLearnt muscle memory can be 'forgotten' if unused for some time, but can be easily regained with further exposure - which is why you can never really forget how to ride a bike as long as you've learnt how to ride one.\n\nMuscle atrophy however, refers to muscles becoming smaller. This downgrading in size can be either physiological or pathological.\n\nPhysiological atrophy can simply be say not going to the gym for a couple of weeks. One can gain back said muscle mass quickly if it's just physiological atrophy.\n\nPathological atrophy on the other hand is much more problematic. Basically people with pathological muscle atrophy have some sort of disease where their muscles become weaker and smaller as time passes. The cause of this varies and can range from neurological causes to say starvation.\n\nBut to answer your question, a rule of thumb would be - if the nerve connections are still intact, there is always a chance of regaining previously learnt skills/muscle memory with further repeated exposure (look at retired boxers - they sometimes just need abit of practice but they never really lose their skills/training).\n\nIf the nerve connections are faulty (be it within the brain or the nerves), then it's *usually* impossible/extremely difficult to regain previously learnt muscle memory.\n\nThe catch is that the brain might attempt to learn how to cope with this, but the performance can never quite be the same (eg someone with spinal injury learning how to walk again. They will eventually learn to walk properly after some time, but it will never be the same).\n\nedit: reorganising paragraphs to make it flow better"
]
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[],
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|
2io6vx | the difference between the domain controller and an active directory. | This always confuses me, so I would appreciate the help. Thanks! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2io6vx/eli5_the_difference_between_the_domain_controller/ | {
"a_id": [
"cl3v6h0"
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"text": [
"Active directory is the place where information about people and organizations are stored and accessed. The domain controller is the host(s) on the network that _manage_ membership within the network, often using active directory as it's source of rights, permissions etc. The domain controller is the air traffic control tower, active directory holds all the flight schedules. In practice on small networks they reside on the same network device/server."
]
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[]
] |
|
1tn9jy | why do american trucks and european trucks look so different? | After playing Euro Truck Simulator, I noticed that Euro trucks are flat in the front and don't have noses, where American trucks have long noses. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1tn9jy/eli5why_do_american_trucks_and_european_trucks/ | {
"a_id": [
"ce9m1nq",
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7,
2
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"text": [
"Hahaha I WAS wondering, is this guy playing that trucking game? ETS2 is my current gaming addiction, I can't stop playing.\n\nAnyway it's mostly vehicle length regulations. For a while America had similar, either on a state-by-state or federal basis, I can't remember; one can still see older trucks of that design puttering around. Example: Peterbilt 362, Kenworth K100\n\nThe term for them is COE, Cab-Over-Engine. Advantages include better visibility from the cab, and better maneuverability. Disadvantages are a rougher ride since the driver sits right over the front axle, decreased safety for lack of a crumple zone in front, poorer aerodynamics. \n",
"American regulations that stipulate the maximum length of the vehicle measure the length of the truck and trailer separately, so there is no penalty for building a longer truck, within reason. European regulations measure them as a single unit. Because of this, the trucks themselves must be shorter, so that the length of the trailer (and therefore capacity) can be maximized."
]
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[],
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|
61wrjd | If we were to colonize one of Jupiter's moons, would Jupiter have cycles the same way our moon has lunar cycles? | If we were to somehow colonize one of Jupiter's moon, would Jupiter go through cycles like our moon? Would we look in the sky and maybe see Jupiter like a crescent? | askscience | https://www.reddit.com/r/askscience/comments/61wrjd/if_we_were_to_colonize_one_of_jupiters_moons/ | {
"a_id": [
"dfi2tqq"
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"score": [
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"text": [
"Yes, if you were on the side of the moon facing Jupiter, you would see Jupiter cycle through its phases every day. Jupiter's location on the sky wouldn't change during the course of the day, but the fraction of Jupiter's face illuminated by sunlight would cycle through the full set of phases.\n\nIf you were on one of the bigger moons, you could probably also watch your own moon's shadow on Jupiter.\n\nFor an example of how this might appear, [here is an image of a crescent Jupiter](_URL_0_) taken by Cassini."
]
} | [] | [] | [
[
"https://saturn.jpl.nasa.gov/resources/1660/?category=images"
]
] |
|
54w75b | why exactly are whole life insurance policies considered scams? | Almost everything I've read recently has said not to purchase and/or contribute to the policy. Doesn't the cash value grow within the policy as you contribute to it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/54w75b/eli5_why_exactly_are_whole_life_insurance/ | {
"a_id": [
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"text": [
"The school of thought that calls them expensive has several solid points in their favor:\n\n* Insurance is supposed to protect the buyer against risks that would wipe them out financially. Life insurance makes a lot of sense when its on a sole breadwinner (protecting a spouse who is staying at home to raise the children and whose earning power is lower). However, once the children are gone and the home is paid off, maintaining the same level of insurance isn't always prudent. Term plans allow adjustment (or dropping coverage all together) in this case, while whole life plans maintain the more costly coverage. \n* Whole life plans are a sort of bundle, and many buyers might be better off picking the parts of the bundle they prefer. As a simple comparison, how does the cash value compare with buying a term policy and investing the difference in premiums? \n* Especially in the golden years, whole life plans tend to be priced to cover the needs of those wishing to use the plan for estate planning purposes, which makes them quite expensive for anyone whose estate is less than the minimum threshold of the estate tax. ",
"Only buy enough coverage for what you need, a hybrid policy is best. Have a term for X years while you have a mortgage etc, then after it goes to a lower reasonable coverage. Ofcourse you should shop around and see what rate are best. some policies can be paid off in 20yrs and not have to pay a dime after. plan early so you dont have to worry."
]
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eko88x | why do anime characters have to yell the name of their move? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/eko88x/eli5why_do_anime_characters_have_to_yell_the_name/ | {
"a_id": [
"fdcr94l"
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"score": [
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"text": [
"It's so that the \"move\" is identifiable to the audience. Think about how many kids have tried the \"kamehamaha way\" irl. Do you think that happened by accident? That kind of playground nonsense is what keeps shows like dbz and powerrangers popular."
]
} | [] | [] | [
[]
] |
||
86o7k6 | sperm competition | Im aware that sperm compete to get to the egg, but what im wondering is how is this helpful? wouldnt this just promote males that produce fast sperm but potentially have less than adequate genes or does having fast sperm correlate to good genes? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/86o7k6/eli5_sperm_competition/ | {
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"I may be wrong, but I'm pretty sure it doesn't have much of an effect between males, but it is this way because then the healthiest, usually the fastest, will reach the egg first. So it has less to do with intraspecies competition and more with trying to ensure the health of any given offspring.",
"Sperm from the same man don't really compete with each other. It only takes one to fertilize the egg, but the reason a male releases millions of them is to increase the chances that one of them will make it. Some of them die along the way.\n\nIf the female mated with other males around the same time, releasing more sperm also increases the chances that one of yours will make it, and not the other guy's. So, they could compete with another male's sperm, but not with each other.",
"Better genes = Genes that result in progeny. In short, it would be helpful at passing on better genes.",
"Evolution does not need to be helpful. Evolution does not try to be helpful. Evolution is an emergent effect that happens as a result of things that copy themselves being more likely to exist. Nature doesn't care about being helpful, it just does things. Often helpful things get copied more often, because \"helpful\" means they help you survive more, but sometimes they don't.\n\nIf faster sperm are more likely to get the egg, then more babies will be born from faster sperm. If the sperm carry their speediness in their genetic code, then those babies will grow up into men with faster sperm.\n\nSame for any other sort of attribute sperm might have like \"healthiness\" or \"longevity\" that make them more likely to get the egg. It doesn't matter if it's helpful to anyone, it just happens."
]
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4lqs51 | What was the difference between a marquess and earl in English peerage? | [deleted] | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4lqs51/what_was_the_difference_between_a_marquess_and/ | {
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"The title of Marquess/Marquis in the English/British peerage has only symbolic connection to the title's antecedents of border / \"marcher\" lords on the Continent or in England and Wales. \n\nThe actual use of Marquess in the peerage was to be a title conspicuously higher and more rare than that of Earl, but not dilute the rank of Duke which was (in general) reserved to royalty and public servants of extremely great and unusual distinction. In general, someone who had particularly distinguished himself while already an earl might hope for elevation to the marquessate. \n\nAs with all other peerage titles, it was never associated with any particular (or indeed, any at all) grants of land for private ownership, to say the of bestowal of feudal or governance rights over a territory. Remember that England and then Britain were from the reign of William the Conqueror onward, subject to minor exceptions unitary states, governed by the King's ministers and sheriffs with greater or lesser cooperation of Parliament. The power of a landed peer over his lands wasn't as a ruler but as a private owner. Those powers could be quite considerable of course, but they were artifacts of ownership and not noble title. \n\nIn addition to higher formal social rank, Marquesses differed (and differ) from Earls insofar as they are entitled to the prefix \"Most Honourable\" *vs. \"Right Honourable\"), if they happen simultaneusly to hold an Earldom with a different title their oldest son can be known as \"Earl X\" (as opposed to an Earl's oldest son being able to be known as no more than \"Viscount X\") and their younger sons are entitled to the title of \"Lord\" (vs. \"Honourable\"). But these were not and are not really of much consequence in the second and subsequent generation. Someone who inherited a marquessate had in reality the status among peers afforded to him by his wealth and talent. "
]
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[]
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xuaca | when i sneeze i only sneeze once or twice, my so sneezes up to seven times. elif why does this happen? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/xuaca/when_i_sneeze_i_only_sneeze_once_or_twice_my_so/ | {
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"Most likely, you are sneezing with more force than your SO is. Sneezing is a way of removing irritants from the nasal passages, whether this be pollen, dust, cat hair, etc. If you are sneezing at 40mph, and your SO is sneezing at 10mph, it will take more sneezes to dislodge whatever is irritating his or her nasal passages.\n\nThe other possibility is that your SO's nasal passages are more irritated by allergens and pollutants, so this causes his or her nasal passages to react more violently. Think of it this way: sneezes are essentially muscle reflex, similar to any other muscle in your body. If someone hits you in the leg with a roll of wrapping paper, it will hurt very little if at all. If someone hits you in the leg with a baseball bat, you will have a strong reaction both in emotions and in physical pain.\n\nIf the same happens with sun-sneezes, then it is psychological rather than physical, because people get used to sneezing a certain amount of times no matter what the cause."
]
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||
bj94q5 | How high do mountains have to be to affect precipitation? | This one has been bothering me pretty much as long as I've known: Obviously, mountains cause rain shadows by blocking rain, so there's a dry area right next to the ocean. However, where's the limit? For example, is like half a kilometer high enough? | askscience | https://www.reddit.com/r/askscience/comments/bj94q5/how_high_do_mountains_have_to_be_to_affect/ | {
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"One of the better answers to this question comes from this [paper](_URL_1_). These authors use the Andes as a (huge) natural laboratory and compare topography and satellite derived precipitation measurements to (among other things) try to understand what topography is necessary to produce a significant orographic effect. The answer is not given strictly in terms of elevation, because what is actually important is the relief, which you can think of as kind of the ruggedness or steepness of the topography over a specified length scale. When a geomorphologist uses the term relief (or more correctly, 'local relief'), we have a very specific meaning, which is the difference between maximum and minimum elevations within a specified distance. What they find is that ~1km of 3km relief is sufficient to produce an orographic barrier. A spot that has 1km of 3km relief means that from that spot, the difference between the maximum and minimum elevation is at least 1 km within a circular area with a radius of 3 km (centered on the spot). These authors didn't directly explore this parameter, but there also needs to be some amount of continuity of the high relief area / areas to form an effective barrier that air masses can't easily move around. Ultimately, it is the relief that is important, as opposed to the absolute elevation, because the orographic barrier is created by the [(relatively) rapid uplift, and cooling of air masses](_URL_0_). In areas with high elevations, but that are reached over longer distances (i.e. with less relief), this effect is not as prominent (i.e. air masses aren't pushed up quickly enough) and thus an orographic barrier is not formed. They see this in their data from the paper, where there is not a pronounced orographic barrier in southern Bolivia and northwestern Argentina because of lower relief at the mountain front, even though the total elevations are comparable (or even greater) than elsewhere in the range."
]
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"https://en.wikipedia.org/wiki/Orographic_lift",
"https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2007GL032011"
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|
3mtq8n | why do car lock remotes not lock/unlock other cars within their range? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3mtq8n/eli5_why_do_car_lock_remotes_not_lockunlock_other/ | {
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"Both the remote and the car use a pseudo-random number generator with the same seed. A psuedo-random number isn't truly random, but acts like it. Two computers with the same seed number and using the same random function will generate the same sequence of \"random\" numbers.\n\nWhen you press your remote, it sends the next number in it's sequence to the car. On your remote, it assumes that the request was received and puts the next random number in memory. In the car, if it gets the signal, it checks to see if that was the number it was expecting. If it is, the car unlocks and it puts the next number in memory.\n\nIf you press your remote and you are out of range, the car doesn't get the number it's expecting. When you get closer, it gets the 2nd, 3rd, or maybe even the 20th number *after* the one it was expecting. Once your car gets that number and it is in a list of next available numbers, it skips the ones that were missed.\n\nBasically, all the cars in range of your remote have a list of codes they are expecting from their remotes.\n\nCar A's list is (simplified): 75, 23, 145, 87, 33, 14, 56, 47, 13, 88\n\nCar B's list is : 132, 99, 12, 65, 59, 39, 162, 74, 63, 28\n\nYou have car A. The code in your remote is 75. When you click unlock, your remote sends \"75\" then moves to \"23\". Your car gets \"75\" and unlocks, and *it* moves to 23.\n\nCar B also heard \"75\" but that number isn't it's list of possible codes, so it just ignores it. It's still waiting for \"132\".\n\nJoe comes along who owns car B. He click's his remote which sends \"132\" but he's out of range. His remote moves to \"99\". He tries again and sends \"99\". Still out of range, and the remote moves to \"12\". He tries again, his remote sends \"12\" and moves to \"65\". This time his car hears \"12\". It was expecting \"132\" but 12 *is* in the list of valid codes so it unlocks. His car now advances the list to \"65\" and his car and the remote are now in sync.\n\nYour car was still nearby and heard all of Joe's codes, but none of the numbers he sent were in your car's list so they were ignored.\n\nThat's a simplified example, as the codes are actually 40-bit numbers or larger, so the chances of any two cars having the same number in their \"list\" are extremely remote. Not impossible, but so unlikely as to probably never happen in the history of mankind. And even if it did, by chance, the next number in sequence would be different.\n\n"
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61gow5 | Does a "simple" video have a smaller file size than a "busy" one? | If I'm watching a video that has very little activity on the screen (like a music video on YouTube that just has the album cover) will that have a similar file size to something that is a lot busier? I feel like the video codec should be able to recognize that there isn't anything happening and reduce file size accordingly.
Thanks | askscience | https://www.reddit.com/r/askscience/comments/61gow5/does_a_simple_video_have_a_smaller_file_size_than/ | {
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"For most compressed formats that is true. They generally try to reduce the file size by compressing individual frames in the video (intra-frame compression) and by recognizing similarities between frames (inter-frame compression). That means temporal properties of the video can be exploited to only encode differences from the previous frame rather than an entirely new frame. \n\nConsider a video shot from a handheld camera: There is going to be some movement but in between subsequent frames, many parts of the frame simply move from a spot to a couple pixels over. Modern compression algorithms compute these changes and encode them appropriately. That means during playback, the player has to decode this and compute a frame from the previous rather than simply being able to read it and display immediately. The savings in file size are well worth this computation though.\n\nNow one concern you might have is that skipping to the middle of a video is very inefficient this way: The player has to start from the first frame, add all these changes on top of it until the desired spot in the video is reached. To circumvent this, formats include periodic key-frames that are independent of previous frames and behave as \"anchor\" points for skipping around in the video. See [this](_URL_0_) for more info.\n\nSo in your example a compression algorithm would be able to pick up on the fact that the video isn't changing and would emit a very small video file as a result. \nIn the opposite case, where a video essentially just displays random pixels everywhere, these algorithms would fail completely and maybe even generate larger files than what would be achieved by simply storing a sequence of images."
]
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"https://en.wikipedia.org/wiki/Video_compression_picture_types"
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1crdsx | Why is magnetic attraction more powerful than gravity? Also, is there such things as "magnetic waves"? | askscience | http://www.reddit.com/r/askscience/comments/1crdsx/why_is_magnetic_attraction_more_powerful_than/ | {
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"To my knowledge it is not well understood why the electromagnetic force is stronger than gravity. I'm sure there are hundreds of theories, but there's no compelling evidence for any of them. Right now, it should just be taken as a fact.\n\nMagnetism and electricity are coupled together such that a magnetic wave always produces an electric wave. This is light.",
"The answer is nobody has any idea \n\n_URL_0_",
"As far as exactly why, we currently don't. While gravity is the weakest force in physics (strong nuclear, weak nuclear, electromagnetism, gravity), it is the relationship of the sizes and distances of objects that is relevant comparably. Thinking in planetary terms, gravity is what keeps planets in orbit, the entire solar system in orbit, and is so strong at certain points where black holes are present light cannot even escape its pull. While weak comparably in our experiences, gravity does play a huge roll in the entirety of the universe and is scaled to as such. \n\nYes there are magnetic waves. For familiarity, an electro-magnetic pulse is a prime example. Also the production of electricity has many good examples of where electromagnetic waves are utilized. I'd suggest looking anything up on how we produce power, very interesting and informative. "
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1w2yxw | Why can't we make an all in one Group A Strep Vaccination? | Group A Strep vaccination research is difficult due to the number of different serotypes. Few vaccinations make it to the trial stage, and even then they only work against a few of the many types. What prevents us from combining all the Strep vaccines into a all in one vaccine? | askscience | http://www.reddit.com/r/askscience/comments/1w2yxw/why_cant_we_make_an_all_in_one_group_a_strep/ | {
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"This is very complicated answer. Here's a pretty good [review](_URL_0_).\n\nBut long story short, there are two main reasons:\n\n1) There is a theoretical (but possibly demonstrable) risk of rheumatic fever after vaccination. Presenting multiple antigens (such as you suggest) can drastically increase the chance of such a Type II immune reaction.\n\n2) Each vaccine is developed by different companies--there is no incentive for them to come together and jointly fund a universal vaccine (even if it was technically possible)."
]
} | [] | [] | [
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"http://journals.lww.com/pidj/Documents/Feb%2013%20ESPID%20Progress_Toward_a_Global_Group_A_Streptococcal.19.pdf"
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|
88yfuf | Did medieval European clothing have pockets? | In films and fiction books they always just shove something in their tunic and it magically stays there until they need it. It seems unlikely. How did people store personal belongings on them? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/88yfuf/did_medieval_european_clothing_have_pockets/ | {
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"The short answer is no, no pockets.\n\nThe long answer is that you wouldn't generally speaking have pockets built into your clothing like we do, but you might have a pouch, purse or scrip which fastened to your belt or girdle. A drawstring design like [this](_URL_0_) done on linen would be a good guide for a woman's alms-purse - it dates to the mid-1300s in France - though this is of course an unusually ornate and costly example, given just how much gold and silver thread is involved! Samite might also be an option, but only for the VERY wealthy.\n\nYou see how it has the drawstring across the mouth of the bag (disregard the tassels, they're decorative), and then the two loops of thread? The bag would be tied or hooked on at about hip height, next to a ring of keys, her personal knife for mealtimes or any other personal items the owner wished to keep convenient.\n\nBags for men might be of a similar drawstring type (this was common for both men and women) or might be a more sturdy leather scrip. "
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17v9e9 | Would battles or skirmishes ever be started out of boredom in the middle ages? | I know from reading narratives from the Vietnam War that many times soldiers would intentionally walk into an ambush just because they were itching for a firefight, I guess with the idea that they were slightly safer knowing one was coming up than if they were legitimately ambushed.
I was also thinking about a recent post about a large battle in online game EVE, and despite it being a game, seems to unwittingly model the vague and tenuous vassal loyalty of the feudal era quite good, and how a small skirmish started over boredom can quickly escalate into a massive battle.
Was wondering if this was ever the case in the middle ages, whether it be from roving armed bands, or knights in contested regions.
I'm assuming in a lot of ways, the whole Crusades might be counted as an instance of this? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/17v9e9/would_battles_or_skirmishes_ever_be_started_out/ | {
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"I don't know that actual battles would spring up out of a couple thousand armored guys not having anything else to do, but I can tell you with certainty that the First Crusade was organized as a result of boredom among the nobility.\n\nBecause there weren't any major wars going on, the knights were basically just raping and murdering throughout the countryside out of sheer ennui; when Urban called them to Crusade, he was attempting to direct their martial energies into more productive channels."
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1pbx9k | how does frostbite destroy and permanently damage flesh? and how do you know if you get it? | I feel like I have had mild cases of frostbite, where my hands would be hot once they are in a controlled environment, and my fingers look like they are swollen. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1pbx9k/eli5_how_does_frostbite_destroy_and_permanently/ | {
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"I'm no medical expert, but my understanding is as follows:\n\nFrostbite is caused when tissue freezes after prolonged exposure. As your body cools, blood is drawn away from extremities such as fingers or toes and concentrated in the core to protect vital organs. This drawing away, coupled with a constriction in the blood vessels in extremities, contribute to the beginning of frostbite as the ambient temperature fall\n\nThe tissues freeze and this causes cellular damage, as water expands when it freezes - this is part of the reason human cryogenics is not yet a true reality because nobody has yet figured how to freeze living tissue without causing damage. \n\nMild frostbite, also called frost nip, concerns damage to the upper layers of skin. Second degree begins to go deeper and typically presents with extensive blistering, with third and forth degree being the point where amputation is going to be likely due to level of damage caused to muscle and nerves. When people say 'frostbite' they are thinking of the latter stages.\n\nFrom what you said, you don't have frost bite per say, but take care of your hands. They should be fine soon enough but if not consult a doctor. \n"
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73egxu | If we know the bacteria that cause pneumonia why can't we make a vaccine for it? | askscience | https://www.reddit.com/r/askscience/comments/73egxu/if_we_know_the_bacteria_that_cause_pneumonia_why/ | {
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"Pneumonia just refers to an infection in the lung parenchyma. It can be caused by many bacteria and viruses but the most common is *Strep pneumoniae*, also called pneumococcus. \n\nThere are 2 vaccines for pneumococcal pneumonia: Pneumovax and Prevnar. The first covers 23 serotypes of the pneumococcus bacteria and the second covers 13 of the more virulent strains. There are specific age and comorbidity guidelines for who gets the vaccines. \n\nWhy doesn't everyone get the vaccine? Because of cost, risk/benefit, and low person-to-person transmission of pneumococcal pneumonia. \n\nWhy does pneumonia still exist if we have a vaccine for them? Because there are other types of bacteria and many other serotypes of pneumococcus that can cause pneumonia.",
"CDC website:\nThe pneumococcal conjugate vaccine (PCV13 or Prevnar 13®) protects against 13 types of pneumococcal bacteria.\n\nBefore the vaccine, there were about 700 cases of meningitis, 13,000 bloodstream infections, and 200 deaths from pneumococcal disease each year among children younger than 5 years old. After children started getting this vaccine, these numbers dropped quickly.\n\nCDC recommends PCV13 for use in infants and young children and adults 65 years or older. Older children and adults younger than 65 years old who are at increased risk for getting pneumococcal disease may also need a dose of PCV13.\n\nThe pneumococcal polysaccharide vaccine (PPSV23 or Pneumovax®) protects against 23 types of pneumococcal bacteria. CDC recommends it for all adults 65 years or older and for those 2 years or older at increased risk for disease."
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4pxvnc | why do high-end restaurants do not show pictures of their food in their menu? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4pxvnc/eli5_why_do_highend_restaurants_do_not_show/ | {
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"From what I've heard, food is very difficult to photograph well. That's why there are people who's job it is to set up food for photography. I've seen some restaurants around here that tried to do it themselves, and it looks terrible in the picture. ",
"I'm married to a chef. The wow factor on presentation is important to him, and would be ruined if everyone knew how their food was going too look before it came out.\n\nFlexibility is important as well. If the kitchen is slammed, no one is going to have time to check against the menu picture to make sure the food matches perfectly.",
"In addition to the good answers already provided..... \n\n When I worked in 'fine dining' restaurants, they used lots of veggies and fruits 'in season', so the dish would change throughout the year. \n\n Also, different head/sous chefs have their own versions of the same dish (ingredients, sauce and presentation) The head chefs I've worked for would NOT make an entree to match a photo just because it's on the menu and quality menus aren't cheap to print. They consider their work art (which I agree with) and would be insulted.\n\nNow that the Internet's here, most fine dining restaurants include a photo or two of their signature dish(es) to showcase their presentation. They're not often labeled and can easily be swapped out (much cheaper than changing menus)",
"Expensive food is made to impress you. Cheap food is made just to get by. I feel like pictures make inexpensive food more liable so you can order it without wondering what the heck is this gonna be like? Where as expensive food gives you the same confidence as a picture for the fact that you're paying more to make sure its something good.",
"There's the other factor nobody is discussing, which is that having pictures of the food wastes menu space and makes for complicated and ugly layout. ",
"I've actually been through this back and forth with a chef during a website redesign process where she and one of the owners were basically in an argument with one of the other owners about how much photography to show on the website. There's a very strong association of food photos on a menu to things like plastic diner menus. It's not considered high-class.\n\nAlso, as far as the actual menu goes, the more high-end the restaurant the simpler and sleeker the menu tends to be. There's no where to /put/ pictures on the actual menu itself.",
"At higher end places, the presentation of a dish might change on a chef's whim, and most use seasonal veggies so the pictures likely wouldn't be accurate at all. Also, places like that change their menu regularly (mine changed menus once a week), and taking new pictures and printing photos is a waste of time and expenses. "
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2aok3m | There are so many theories about the beginnings of agriculture. But which one is the most accepted by the modern day historian? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2aok3m/there_are_so_many_theories_about_the_beginnings/ | {
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"This really is more of an archaeological and anthropological question so I suggest cross-posting it to /r/AskAnthropology. \n\nBesides that, can you be more specific about which hypotheses you are referring to? There have been tons of hypotheses suggested, and a few are better-accepted, but it's difficult to just blanket critique everything. \n\nAlso, agriculture was developed independently in at least 7-8 different places. Although there are some similarities between them, so we can generalize a little, each place had its own unique geography and the reasons and way that agriculture developed in each place are somewhat different. So it's hard to say that there is any single reason, though many archaeologists have tried to do that. But I don't focus specifically on early agriculture and I'm not up to speed on current ideas about it, so I would rather leave the real answers to other people."
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||
4jz93s | why does ~x = -x - 1? | I've always been confused about why the bitwise negation `~` of any number `x` equals `-x - 1`.
Should the bitwise negation flip each bit from 1 to 0 and vice versa?
For example, `~10 = -11`, but the binary representation of `10` is `1010` and the binary representation of `-11` is `-1011`?
How come that works? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4jz93s/eli5why_does_x_x_1/ | {
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"In binary math, for most systems, we use what is called Two's complement. It is a way to eliminate the possibility of a positive and negative 0.\n\nThe highest bit (the left-most bit in a binary sequence) is the sign bit. If it is 1, it is a negative number. If it is 0, it is either 0 or a positive number.\n\nIf you were to flip 0, and we didn't do this, you'd end up with all 1s. Instead of having to check between 2 different versions of 0 (one 'negative' and one 'positive'), it is more efficient to just check against one version. This gives an extra integer to use and still works out to correct answers when using binary math (addition and subtraction) without requiring conversion.",
" > For example, ~10 = -11, but the binary representation of 10 is 1010 and the binary representation of -11 is -1011?\n\nRemember that we're not using simple binary, we're evaluating a particular data type (signed integer), which- in the simple case- always uses the same number of digits (bits).\n\nAn 8-bit signed integer ranges from 0000 0000 to 1111 1111, right? The convention we use is that 0000 0000 is 0; 0000 0001 is one, and so on, until we get to 0111 1111, which is 127; after that, with 1000 0000, we jump to (or, the way it's better to think about it, loop around to) -128. And then comes 1000 0001, which is -127, and so on.\n\nThe upshot of all this is that, except for that weirdness between 127 and -128, adding 0000 0001 (ie, 1) to any byte value gives you the same answer as adding 1 to the matching number. (You may have to dump a carry digit from the 128s place.)",
"Suppose you had a counter that had four digits. If it's on 9999 and you add one more, it rolls over to 0000. So you could say that one less than 0000 is 9999. And if you want to multiply something by negative one, you have to find the number you add to it to get 0000. If you subtract each digit from 9, then you get the number you add to it to get 9999, so if you add one more you get 0000.\n\nThis is basically what computers do, except with binary instead of decimal. And you subtract digits from 1 instead of 9. And that's just notting them, so it's easier."
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6mnnwa | Are medical tests structured to be more likely to give a false positive or a false negative? | By "test" I mean something like a pregnancy test or strep throat test. | askscience | https://www.reddit.com/r/askscience/comments/6mnnwa/are_medical_tests_structured_to_be_more_likely_to/ | {
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"Both. You're thinking of sensitivity (percentage of true positive) and specificity (percentage of true negative). A gold standard would have 100% of both. I don't think there's any \"structure\", what you see if what you get with a test (you compare the test with a gold standard). Tests that have low sensitivity and low specificity will rarely be used. \n\nThe selection of which test to use will be determined depending on the situation. If you need to know is someone has a life-threatening disease you would want a test with high sensitivity (few false negative) because the amount of false positives doesn't matter as much (because those who need treatment will get treatment).\n\nIf the treatment itself is very dangerous we may want high specificity (few false positive).",
"There are several properties of tests that make a difference in different circumstances. As already mentioned, sensitivity and specificity are the most commonly known/used [measures](_URL_0_). Other helpful measures are positive predictive value and negative predictive value. Depending on the specific circumstances, you'll want to maximize one or the other of these (more on that later). First, let's define some terms.\n\n* True Positive (TP): a case where the test says the person has the condition and the person actually has the condition\n* False Positive (FP): a case where the test says the person has the condition, but the person does NOT have the condition\n* False Negative (FN): a case where the test says the person does NOT have the condition, but the person actually DOES have the condition\n* True Negative (TN): a case where the test says the person does NOT have the condition and the person actually does not have the condition\n\nSensitivity is TP / (TP + FN), so of all of the people who you test who actually have the condition, what percent does the test accurately identify? If it's really important not to miss anyone with the condition, then you'll want very high sensitivity. How do you get 100% sensitivity? Assume everyone has the condition. Here's a pregnancy test with 100% sensitivity: \"are you a mammal?\" - 0% of pregnant people are non-mammalian, so you will have zero false negatives. But that's a terrible idea - what's the point of the test at all! Good point. This is the sort of thinking that will be helpful in optimizing your test.\n\nSpecificity is TN / (TN + FP), so of all of the people who you test who do NOT have the condition, what percent does your test accurately identify? If you really don't want to be wasting time/resources on people who do not have the condition, then you want high specificity. Here's my 100% specificity pregnancy test: \"are you a mermaid?\" - mermaids are not real, so there will be no false negatives. Again, a terrible idea.\n\nPositive Predictive Value is TP / (TP + FP), so when the test comes back positive, what are the odds that it's correct? This is a much more meaningful question for an individual patient than sensitivity and specificity. What are the odds that I'm pregnant given that the test said I am? Whether to optimize this again depends on how you'll be using the test results. Say it's a pregnancy test, it's positive, and you decide to stop drinking for a week and spend some of the money you saved by not buying alcohol on some prenatal vitamins while you wait to get an appointment with someone who has a better pregnancy test than mine (\"are you a mammal?\"). No big deal, so not that important to optimize. However, if your response to pregnancy is to take a medication with some unpleasant side effects (e.g., RU486), or rush to marry your deadbeat summer fling, drop out of school, skip the prenup, change your name, and upgrade your health insurance to something below bottom tier, then you'd probably like to be a bit more sure.\n\nNegative Predictive Value is TN / (TN + FN), so when the test comes back negative, what are the odds that it's correct? Again, more meaningful to the individual, and optimizing depends on what you plant to do with the information.\n\nAccuracy is (TP + TN) / (TP + TN + FP + FN), so what percent of the time is the test correct, regardless of whether it's saying positive or negative? This can be heavily influenced by base rates (what proportion of the population has the condition). So if 1% of the people I test are actually pregnant, and I use by mammal test, then my accuracy will be 1%. But if 90% of the people I test are actually pregnant (say I test only people in an obstetric pre-natal care waiting room, including spouses and children), then my accuracy will be 90%!!! Actually, everything is influenced by base rates - the more common something is, the more true positives you'll get, The less common it is, the more false positives you'll get.\n\nOkay, so how do you actually optimize a test? Most tests rely on a cutoff value somewhere along a continuum. To bring the pregnancy test back to reality, you may check for certain levels of hormones. It's not like hormones go from non-existent to highly prevalent at the moment of conception, but there are increases in certain hormones (I am not an obstetrician/gynecologist/physician of any sort, so I'll leave the details aside). So if you set your cutpoint low, closer to non-pregnant levels, then you'll increase sensitivity and negative predictive value at the expense of specificity and positive predictive value. A higher cutpoint shifts that balance in the other direction."
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mhrow | Data transmission in Space | How does it possible to transmit data from Mars to Earth? (i.e. image transmitted by Spirit)
Under Earth's atmosphere it is possible to use the radio waves for communication but I wonder how to send/receive data in Space? | askscience | http://www.reddit.com/r/askscience/comments/mhrow/data_transmission_in_space/ | {
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"You do not need atmosphere to send radio signals. In fact, it is better without atmosphere. ",
"NASA uses the Deep Space Network to communicate with many of its interplanetary probes, including the Martian ones. It's a network of three ground based sites around the world, each with several large parabolic radio antennas (I.e. satellite dishes).\n\nLots of cool info at [their website](_URL_0_).\n",
"Every TV show we've ever aired has been transmitted to mars. You don't have to direct radio signals to send them into space. A TV show (or radio show) is beamed to your house the same way it is beamed into space.\n\nThere are some other really great posts in this thread which explain parabolic reflection, and why it's useful.",
"You do not need atmosphere to send radio signals. In fact, it is better without atmosphere. ",
"NASA uses the Deep Space Network to communicate with many of its interplanetary probes, including the Martian ones. It's a network of three ground based sites around the world, each with several large parabolic radio antennas (I.e. satellite dishes).\n\nLots of cool info at [their website](_URL_0_).\n",
"Every TV show we've ever aired has been transmitted to mars. You don't have to direct radio signals to send them into space. A TV show (or radio show) is beamed to your house the same way it is beamed into space.\n\nThere are some other really great posts in this thread which explain parabolic reflection, and why it's useful."
]
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1h25pi | were the Saxons a united kingdom, or just a nebulous ethnic group in AD350? | . | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1h25pi/were_the_saxons_a_united_kingdom_or_just_a/ | {
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"While there definitely was not a 'united kingdom', the early Saxon migrations might have been coordinated by one or a few enterprising individuals (Bede's Hengest and Horsa, for example). Germanic social structure in this time was not strictly organised under territorial kings, but did allow for the election/appointment/ascendancy of what the Romans and the Franks call 'kings'; basically charismatic war-leaders who dealt with affairs such as foreigners, flotsam, tolls and trade, sacrifices and the supernatural, and large-scale war. Later authors identify for the Saxons a system of 'satrapes', where each region has its own aristocratic 'head' or representative who in a council could organise larger-scale affairs (such as how to respond to the Frankish wars of the 780s). I do not believe that such a system was as straightforward as the later sources suggest, and neither was it already in place in Saxony 400 years earlier. Think rather of a figure like Attila or Alaric, who unite people from different tribes together in undertaking large scale operations.\n\nThat said, much of the Anglo-Saxon migrations are likely to have taken place as individuals or in small groups, rather than massive organised invasions."
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58h2bv | why pens appear 'bendy' | As a kid we always used to do that thing where you hold a pen/pencil between your index finger and thumb and 'wobble' it, why when you do this does the pen appear to 'bend' back and forth, even though it is rigid and is obviously staying straight, it is that our eyes simply can't keep up, or something more? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/58h2bv/eli5_why_pens_appear_bendy/ | {
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"Believe it or not, like a camera, our brain has a \"frame rate\" or amount of information we can take in per second and process. It's about 15 f/s. (Side note: any motion slower than that doesn't really seem smooth to us.)\n\nSince our minds take in information in this finite way, filling in spaces as it needs to for the perception of motion, we can get fooled by motion blur, like a pencil wiggling, if it's at certain speeds. That's why when you're doing the trick, you need to get it just right: too slow, and it looks stiff, too fast, and it's the same as a fan blade spinning.\n\nThere's also something to be said for the fact that to do the trick, you need to keep the middle in the same place. This makes it seem like there's a point at which the pencil bends, a point of reference for our eyes. \n\nHope that helped ",
"This illusion is due to a strobe effect. It is the same phenomenon that makes a helicopter's blades look like they are spinning slowly on video. Another example is a wheel spinning backwards. In videos it happens because the object is turning at near the same rate as the camera captures frames. Now in real life, any light that flickers can create this effect too. Old TVs and fluorescent light tubes flicker really fast. Your brain glosses over those moments of darkness so the light appears to be constant, but you can easily see the strobe effect it produces on your pen when you wave it quickly. Your brain tries to piece together the short glimpses it gets of the pen, but it's not perfect so the pen looks bent."
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2x9egw | why is society so averse to people taking their own lives? | I mean I understand the social stigma around suicide, but with the /r/videos post on the front page showing a guy getting shot to "save his life", I can't help but wonder why a society would make it illegal to claim one's own life. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2x9egw/eli5_why_is_society_so_averse_to_people_taking/ | {
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"Because we are wired to want to live. Things like fear and 'flight or fight' mechanisms were evolved to help us survive and stay alive. So when someone wants to kill themselves something is \"off.\" The vast majority of people that end up killing themselves have a mental illness . So a person that wants to kill themselves has over come the will to live plus probably has a mental illness meaning their ability to rationalize their actions is compromised. So as a rational society we have deemed suicide to be irrational. ",
"because the state-corporate society needs people to for sustenance ",
"There are a lot of emotional and cynical responses to your question, but only a few of them touch on a small number of the reasons that suicide is considered a crime.\n\nThere is an emotional basis to making it criminal to kill yourself. Most suicides (like most homicides) are attempted as a result of hasty decision made while under severe mental and possibly physical stress. It isn't common for suicide attempts to be cold, logical and rational decisions(though some are), and is often viewed as a permanent solution to what is most likely a temporary problem. \n\nBut there are a lot of non-emotional reasons for why suicide is considered a crime. The first and coldest reason is that someone committing suicide is about to waste a lot of people's time and a lot of money. Someone's gotta investigate the incident to make sure it wasn't homicide. Someone's gotta clean up the mess you left behind. Someone's gonna have to provide grief counseling for the people you left behind. A successful suicide victim means a lot of work and man-hours spent by the rest of society with absolutely zero gain to show for it (some might argue that if the person committing suicide was a drain on society's resources there is a gain, but forget that this person still had the remainder of their life ahead of them to start being a positive contributor to society). This puts the act of suicide into the category of selfish behavior. \n\nIt goes even further, though. Each person in civilized societies that have decided to make suicide a crime represents a significant investment made by that society. A lot of money, time, and resources went into bringing you up. If you're like most people, you went to a public school which is paid for by society under the expectation that the basic education you recieved will enable you to be a productive member of society willing and able to contribute. Your parents, likely also contributed a small fortune and significant time to raise you into adulthood, and western society has a reasonable expectation that this investment is worthwhile because you will carry on the family legacy and hopefully provide care for your parents when they are no longer able to care for themselves. Suicide throws all of that time and investment away, and often its for no good reason. So a successful suicide attempt not only costs society a decent chunk of time and money to deal with after the fact, it also represents a significant loss in all the time and resources invested in keeping you alive and molding you into a productive member of society from the day you were born.\n\nAnd finally, there is debt to be considered. A significant number of suicide attempts are made as an attempt to escape crippling debt. A successful attempt can often result in the party that loaned you money having to swallow the loan as a loss. By making suicide illegal, police forces now have reason to protect the economic interests of lenders by preventing a suicide attempt taking place. It sounds callous, but its really not fair to the banks and other lending institutions to have to swallow a huge loss because the person they loaned money to offed himself to get out of it. If it weren't illegal, you'd have situations where people would take out massive loans or open up lines of credit to spend frivolously in order to really enjoy their last days on earth before killing themselves and not having to deal with the consequences.\n\nSuicide is illegal to protect the interests and investments society has made into every single individual in that society. A lot of people don't realize how much time and money has been spent on them just to get them to adolescence. Its a massive loss and huge waste that suicidal people aren't in the right mindset to be thinking about. Making it illegal serves to act as a deterrent while also protecting the interests of the society as a whole.",
"You can get as complicated as you want with an issue like this.\n\nBut it basically comes down to most of society has been touched by Christianity, and it is a sin to kill. Which includes killing yourself. Many laws in western countries still adhere, at least loosely, to this. "
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51b0j2 | In most photos of galaxies there seems to be a bright central core. Is that just some giant star or a huge mass of them? | this is just some thing I have noticed looking at all the gorgeous images we have from the Hubel telescope.
| askscience | https://www.reddit.com/r/askscience/comments/51b0j2/in_most_photos_of_galaxies_there_seems_to_be_a/ | {
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"Many hundreds of millions of stars. Look at [this](_URL_0_) ultra high resolution picture of the Andromeda Galaxy. This is a zoomable image, be sure to zoom *way* in. Each point of light is a star or star cluster. Note that in the bright core there are so many stars it becomes difficult to pick out individual ones.",
"It varies depending on the type of galaxy. In many spiral galaxies, there exists a super massive black hole at the center. Usually the light coming from the cores of most of these galaxies are massive clusters of numerous stars. However, in certain galaxies, the black hole itself can be the mechanism for the brightest source of light; gases from stars that come too close to the black hole begin to gather into a sort of \"ring\" known as an accretion disk, which orbits the black hole in varying speeds up to velocities close to the speed of light. Obviously, matter in volumes on the order of countless stellar bodies orbiting one of the most powerful gravitational sources in the universe at near C is bound to generate an insane amount of friction and heat, and thus a a mind-boggling amount of radiation. In certain cases, these \"Quasars\" as they are called can outshine entire galaxies in terms of overall luminescence. "
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oickc | Are there any documented differences between men and women's swimming skills? | After a cruiser hit ground in the middeteranian during the evacuation children and women got to go on the lifeboats first. I am serious now, this actually started a swedish twitter debate about equality between men and women, claiming that your gender should not matter when it comes to getting on a lifeboat and that it's just gender sterotyping.
So my question is, Are there any documented differences between men and women's swimming skills or other factors that might matter? | askscience | http://www.reddit.com/r/askscience/comments/oickc/are_there_any_documented_differences_between_men/ | {
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"The idea of women and children first is rooted in chivalry. It has no real basis on men or women and their swimming ability.\n\nScientifically though women naturally have more body fat than men which makes them more buoyant than their male counterparts. ",
"Like for any athletic task, [the top men always outperform the top women.](_URL_0_) \n\nWomen's lives are instinctively valued more because population growth is more limited by available females than by available males when it comes to reproduction. However, this does not make it \"right.\"\n\n \n"
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3z8nwb | why do songs on the radio sound higher pitched than songs played digitally or on cds? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3z8nwb/eli5_why_do_songs_on_the_radio_sound_higher/ | {
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"The pitch is the same. It can be altered but is not. Your radio is not producing the bass portion as well as the other two. So you pay attention to the treble part more.",
"Sometimes radio stations will speed up songs to be able to fit more of them (and ads) into an hour. The downside is this also slightly raises the pitch. \n\nSource: worked at several radio stations. "
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1trk6p | how does software know that you have already used their 30 day free trial after you uninstall and then re-install the software? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1trk6p/how_does_software_know_that_you_have_already_used/ | {
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"The application could have written the original installation date into the *windows registry* and this information would usually remain untouched after the de-installation.",
"A few possibilities:\n\n* The installer installs some information that the uninstaller doesn't remove.\n* The installer contacts the manufacturer with some unique information about your computer during the installation to check if it's already been installed."
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1mg9i6 | What causes some planes to have characteristic sounds? Is it the airframe, engines, a combination of these or something else? | Example - in this video [taken at the Mach Loop](_URL_0_), the Eurofighter Typhoon has makes a 'moaning' sound which you can pick out before you can see the responsible plane (~3:45), whereas the F-15s make a 'ripping' sound (~4:10) as they pass. | askscience | http://www.reddit.com/r/askscience/comments/1mg9i6/what_causes_some_planes_to_have_characteristic/ | {
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"There are a lot of things at play here. To give a one word answer: engines. However, that is a gross oversimplification.\n\nFirst, I'd like to address the ripping sound. To me, it sounds like a lot of that sound is simply an artifact of the fact that the F-15s are *very* loud and they are pegging out the microphone. Digital microphones encode sound pressure levels on some scale. Sounds are some sort of oscillation of sound pressure. If the sound pressure stays within the bounds of a microphone then the shape of the waveform can be captured accurately. However, when the sound pressure gets outside of the range of the microphone it just pegs out and loses information. What results is pretty much a random square wave with a little bit of preserved sound in the middle.\n\nThe next thing to consider is engine count, which contributes substantially to the sound of a plane. For example, I once was out biking and heard a plane overhead. I immediately stopped and looked up to try to find it in the overcast sky since I could tell by the harmony of the engines turning together \"that has too many engines to be a passenger jet.\" A few moments later I saw the 8-engine B-52 Stratofortress come out of the clouds. To speak to this point more scientifically, when you have two frequency generators (engines, in this case) in the same environment they will interact. If they are at substantially different frequencies then they will appear to be at an interval from each other (e.g. 2:3 is a perfect fourth, (approximately)). If they are closer in frequency then they will just have an interference pattern. Putting more and more frequency sources further complicates the interaction. Also, note that each jet engine produces many frequencies. Different engines will sound different all on their own.\n\nFinally, one must consider how the sound propagates from the engine. The different planes in the video all have slightly different mountings for their engines when it comes to the air pathways around them both up- and down-stream. These pathways will have different resonant frequencies. When there is a resonant frequency that will be the one that is transmitted the best. This can serve to shape the sound that the engines produce (I'm using the word \"shape\" in a non-technical sense here)."
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4qmnuy | How does liquid soap clear the grease/oil layer of dishes in water so quickly? | To clarify, this can be observed by applying a single drop of liquid soap to a greasy pan that's been soaking in water. The thin film of grease disappears almost immediately without any scrubbing action. | askscience | https://www.reddit.com/r/askscience/comments/4qmnuy/how_does_liquid_soap_clear_the_greaseoil_layer_of/ | {
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"Grease is hydrophobic. So it doesn't mix with water. Soap is usually amphiphilic which means it's got one side that mixes with water and one side that mixes with oil. \n\nThe side that mixes with oil is attracted to the oil. The oil soap mix is actually water soluble. The link here might help: _URL_1_\n\nThe speed at which this happens is because of mostly because of [hydration spheres](_URL_0_) which propagate the surface chemistry outward and exerts a force on any suspended particles (amplifies the force of attraction and repulsion). Other factors in the speed are the favorable entropy of the mix over the separation, and the low viscosity of water. "
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4j4i42 | what makes japanese bullet trains much faster and efficient than regular trains? | The question is mostly directed toward the magnetic motor | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4j4i42/eli5_what_makes_japanese_bullet_trains_much/ | {
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"EDIT: /u/L8BCIFPOouJHjFMTFQdY gives a better answer. maglev bullet trains are being introduced, but they are very much a minority.\n\nThey (maglevs) float above the track. With magnets and superconductors and shit. That means no kinetic friction from the track, which means less energy has to be used to get equivalent acceleration.",
"Lots of engineering went into the Shinkansen to make them more aerodynamic than other more typical trains. Wikipedia is nice to provide a [nice list](_URL_0_).\n\nBut to sum up some of the major technological aspects:\n\n1) It's its own private rail network, so the congestion of other lines have no effect. This is actually the biggest thing--they were able to completely design all of the lines specifically for high-speed passenger transport, tunneling through mountains and barely turning at all.\n\n2) It uses continuous welded rails, so there's less bumping up and down when going from one rail to the next.\n\n3) More power in the power lines.\n\nThere's some other stuff I don't see in the article, like the impressive aerodynamics such as minimizing the amount of shock to the vehicle as it enters/leaves tunnels.\n\nWhile it was revolutionary at the time back in the 50s/60s, most countries in the world now employ some form of high speed rail similar to the shinkansen."
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4f329c | national socialism/fascism | How does this system work?
Is racism and genocide a required concept in this ideology?
why did Germany, one of the first countries to adopt this ideology seemed so successful economically and technologically before they ruined themselves in ww2?
Can it be implemented today without all its negative qualities? (racism, genocide, indulging in war etc.)
| explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4f329c/eli5national_socialismfascism/ | {
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"It's not a specific system, but has several parts, but it is very common for these parts to get referred to by a variety of names.\n\nFascism has come to largely be associated with an ideology of reduced tolerance for cultural diversity. The political benefit for fascists is that it is very common that people distrust those in other cultural groups and when a society is under stress people will often desire less tolerance of these others. Politicians can use this anxiety to gain support.\n\nNational Socialism is associated with a form of \"cronie capitalism\". It is a system where government officials decide how the private marketplace is broken and very heavily intervenes to try to make it right. This might often include nationalizing certain industries, consolidating firms, and using public money to start, expand, or improve capital investments (e.g. build or retool factories). This usually involves installing government loyalists into the leadership of these semi-private firms.\n\nWhile there is plenty of literature to question the long-term efficacy of the Nazi party's economic policies, part of the reason it seemed to work so well is that the German economy was incredibly broken, despite having a skilled workforce and a history of strong institutions.\n\nThe Nazi party comes in with a message that Germans are great and we need to restore Germany for the German people who have suffered for too long at the hands of outside influences. They come to power and do everything they can to get industry up and running again, re-writing laws, ignoring debts, and getting people active. Importantly, the Nazi's weren't acting *just* to line their own pockets (even though there was plenty of that going on) but many (most?) truly wanted to make Germany great again, even if 'great' was defined by many top officials as conquering most of Europe as soon as possible.\n\nMaking this work is probably very tricky at best. Command economies are those where the government makes most of the decisions and those economies tend to do a bad job of cutting failing businesses or adapting existing businesses to changing demands. The result is usually that the bureaucrats become more interested in maintaining the status-quo than shaking things up. This likely would have happened in Germany if given the chance (and many say it had already begun).",
"This is slightly tricky because, like all political terms, the specifics of where fascism begins and ends aren't clear and each individual fascist thinker had varying perspectives on it. \n\nThe six key tenets of fascism are \n\n- **Nationalism.** The belief that your nation and its people are special, and have a distinct character with innate qualities, tied to the belief that each person should identify with the nation and seek to serve it. This is typically ethnic nationalism (tied to race/ethnicity).\n- **Autarky.** Autarky is strict self-reliance; the nation should not enter into long-term alliances with other nations and should minimise international trade, the goal being self-reliance.\n- **Militarism.** Placing the military at the core of society, in major political roles; emphasising military service and achievement in culture; believing that your nation has the right to use its military to pursue its interests aggressively, through war or invasion. \n- **Conservativism and reaction.** Conservativism is the belief that ideas, systems, and values currently or previously existing should be preserved and adhered to, and that tradition in itself is valuable. It is opposed to progressivism, the belief that traditional ideas, systems, and values should be analysed and discarded as better alternatives are proposed. Reaction is the belief that recent changes to society have been negative, and wanting to return to a better past. Fascism emphasises conservatism heavily as a matter of doctrine, and every actually existing fascism (Italian, German, etc) has also been reactionary -- the Italian fascists yearned to return to the glory days of Rome and the Nazis glorified the Teutonic Knights and Germanic heroes of old, building up a glorious and epic national mythology that should be returned to.\n- **Corporatism.** Corporatism, despite the name and many people's assumptions, does not mean *corporationism*. Corporatism is the socio-economic system where society is divided into sections (eg Military, Agriculture, Manufacturing) with leaders who have representatives to organise them and negotiate with other leaders. This is opposed to the liberal capitalist system (where every person and organisation is in a free market with no official authorities or representation) and the socialist system (where workers own means of production and operate democratically). Corporatism is a tricky thing to nail down and appears in nonfascist ideologies also.\n- **Anticommunism/antisocialism.** The founder of the movement, Benito Mussolini, was an ex-socialist who created his theory of fascism after, he said, discovering its weakness and \"waking from its terrible spell.\" Fascism is opposed to socialism on almost all fronts: socialism is internationalist (the nation is regarded as a temporary and irrelevant structure, movements seek to transcend borders claiming 'the poor of Germany and France have more in common than the rich and the poor in France'), progressive (tradition is not valued, socialists seek to overturn old systems and develop new ones, and then new ones to replace those), anti-autarky, anti-corporatist. Hitler's rhetoric focused on reaction against Jewish-socialist (\"Judeobolshevik\") plots which had weakened European society and future fascists followed.\n\nNow for the other questions...\n\n > Is racism and genocide a required concept in this ideology?\n\nGenocide no. Racism, yes. The special qualities of the race, the purity of the race and dominance of its homeland, loyalty to your race, and the rights of races to act aggressively towards other races are ideas that appear in the writings of all the major fascists I'm aware of. Hitler's obvious, Mussolini didn't start off this way but became aggressively racist in the 1920s when Italy [colonised Africa](_URL_0_) \"as was its right as the superior race\" (this campaign featured concentration camps, forced starvation, and mass execution of civilians).\n\n > why did Germany, one of the first countries to adopt this ideology seemed so successful economically and technologically before they ruined themselves in ww2?\n\nFirst it's important to note that Germany was very successful economically and technologically for generations before the word fascism was coined. Germany suffered harsh setbacks after WW2 and in the early 20s, but had already been recovering quite well by the time Hitler appeared on the scene. Hjalmar Schacht is widely credited with the revitalisation of Germany's economy after WWI and his major achievements all predated Nazism. The second thing to note is that Germany *did* experience an economic growth under Hitler, but that this was a heavily publicly-funded effort that involved massive rearmament, which isn't any kind of long-term solution or surprise. The United States experienced a similar industrial and economic growth during WW2 due to massive public spending on the war and they did it without fascism.\n\n > Can it be implemented today without all its negative qualities? (racism, genocide, indulging in war etc.)\n\nRacism and militarism are at the heart of fascism, imagining a fully peaceful and non-racist fascist society is pretty difficult."
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6cule9 | Why did "communist" revolutions often originate in agricultural instead of industrial societies? | A quick search on this subreddit showed that a similar question was asked [four months ago](_URL_0_), but the only (interesting) answer is about why Cuba's revolution wasn't really communist.
If I recall correctly communism was a response by Marx and Engels on the exploitation of labourers during the industrial revolution. So what lead to the so-called communist revolutions in mostly agricultural societies? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6cule9/why_did_communist_revolutions_often_originate_in/ | {
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"I'm in mobile and don't have access to my notes or books, so I apologize for the less-than rigorous response. \n\nWhat you're asking about can essentially be restated as \"Why does communist in practice not adhere to Marx's presentation of dialectical materialism.\" As I imagine you know, Marx says society moves from antiquity to feudalism to capitalism to socialism/communism. As you also seem to understand, capitalism will inevitably begin to manifest itself as industrialization, for reasons he makes clear in *Kapital*. Inevitably, Marx reasons, as capitalism continues to deprive the laboring class of both its species-being and true value of the cost of their labor, the laboring class will rise up and seize the means of production. They will institute a dictatorship of the proletariat, then communism will appear somewhere on the distant horizon. \n\nOf course we know this prediction to not have unfolded like that at all. As Western Europe and America continued to industrialize, you see the increase in colonization and the sort of imperialism whose scale Marx hadn't fathomed, nor even truly considered until his last years. This in turn meant that while the colonizing powers enjoyed more growth and more wealth, the colonized became even more impoverished and left behind. Marx didn't account for the fact that capitalism could also be regulated by the state to agree that allowed for an increase in living standards for most of the laboring class, which had the effect of appeasement; the proletariat was fed, clothed, and bedded, and therefore had no need to revolutionize. \n\nThe promises of socialist utopia was much more popular east of Germany, where many nations, notably Russia, were still feudal. There were millions of peasants that frequently starved. They were, in short, more captivated by the promise of liberation through revolution. This is why Lenin (and Trotsky and later Stalin) were successful in initiating the Bolshevist revolution of 1917: Russia was hemorrhaging support among the people for the War, the nobility was hated, and people were starving. Lenin took it upon himself to be the \"subjective element\" (I forget how it was exactly translated in his *What is to be Done*) in the unfolding of Marx's theory of historical materialism, and so triggered the revolution. \n\nWhat does this say about Marx's theories? It's hard to say, because, indeed, Lenin (and Stalin) seemed to think one could jump from feudalism to socialism by taking control of the state and then coordinating its industrialization. History has shown the terrors of this endeavor, it being not limited to Russia but to China as well. \n\nThe short of it is that, like all things, the implementation of such a systemic theory of society will inevitably produce results that differ from one's hopes. As for why *that* is, is a question best left for r/AskPhilosophy. "
]
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"https://www.reddit.com/r/AskHistorians/comments/5oyy9c/why_were_communist_revolutions_predominantly/"
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[]
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3olrb2 | Is the game "Crusader Kings 2" portrayal of 9th Century Italy accurate? | Hi AskHistorians! I'm working on a historical fiction story, set in 9th Century Italy, after the death of the younger son of late "Emperor" Lothair I. However, I'm having trouble finding information about the political and social situation of the kingdom in that time. So I went to CK2 "Old Gods" bookmark, that has a map of 867 Italy with its nobles, dukes, etc. It is accurate by any means? How did the nobility interated with eachother? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3olrb2/is_the_game_crusader_kings_2_portrayal_of_9th/ | {
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"Politically, in terms of who is ruling each region, it's probably pretty close to the truth. *Crusader Kings* can be good about that stuff. That said, the way the nobility in any given region interacted is going to vary, and thus CK2's system is probably to broad to be an indication of what happened. Generally speaking, the the aristocracy of Northern Italy came from a number of populations that gradually became enmeshed with each other. There was the old senatorial elite that held on to some of their power, there were Lombards, and eventually there were Carolingians. The relationship between the Empire and the nobility of northern Italy was in a constant state of flux and the degree that any centralized authority could exert of the region was temporary. No game is going to do that kind of complexity justice.\n\nIf you want more information, *The New Cambridge Medieval History* is pretty good for a general narrative. Chris Wickham has a pretty good book on some of the relationships you're talking about, _URL_1_. It's quite old, but it's not too bad. The best source for your purposes, however, would be the early Middle Ages volume in the *Oxford Short History of Italy* series, _URL_0_. It's more recent and has some good scholars."
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"http://www.worldcat.org/title/italy-in-the-early-middle-ages-476-1000/oclc/48532606&referer=brief_results",
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4ybk8n | What's the difference between a primary source and an anecdote? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4ybk8n/whats_the_difference_between_a_primary_source_and/ | {
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"To clarify, as you asking in the broader sense of historical study, or specifically in the context of the \"No Personal Anecdotes\" rule on this subreddit?"
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1xaxbk | Do historians think Zoroaster existed? | Do historians think Zoroaster existed? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1xaxbk/do_historians_think_zoroaster_existed/ | {
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"Well, you can doubt the existence of virtually every historical figure, especially when it is as remote in history. There is a French scholar who wrote a book in the 1820s to prove (jokingly, of course) that Napoleon was an allegorical figure who never existed. However, names rarely appear out of thin air, except when they have an obvious purpose. It is hard to see why the inventor of Zoroaster should have called him Zarathuštra, *i.e.* “he whose camels are old.” Not that this name is especially shocking in itself; giving deprecatory names is actually a common practice in various cultures, the underlying idea being to “turn away” bad luck (you can call that apotropaic practices, if you want to show off). But it is probably that if you invented a prophet, you would choose a more proper name (like, I don't know, “envoy/priest of Ahura”). Camels may have been an important economic reality, but it did not really translate in terms of symbolic reality into the Gathas (the oldest part of the Avestic corpus). Then, of course, the real importance of Zarathuštra, and the accuracy of the few and obscure written traditions about him can (and should!) be questioned."
]
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7984e8 | why can't we see very small things? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7984e8/eli5_why_cant_we_see_very_small_things/ | {
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"It doesn't even get down to physical properties such as wavelengths. The simple fact is that your eyes have *limited resolution*. Any light that passes into your eye has to be captured by the light-sensitive parts of cells at the retina (the so-called \"rods\" and \"cones\"), and there are only so many cells in your eye.\n\nThe visual size of an object varies with distance. So the closer an object is to your eye, the larger it appears to be, because the light coming from it hits more retinal cells. Past a certain distance, the light from the object is only spread across a single cell. Further away, the object fades from sight as its light blends into the light from its surroundings."
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g7um8 | Does this mean days were shorter while dinosaurs were being awesome because the earth was spinning faster? | [by this, I mean this.](_URL_0_) | askscience | http://www.reddit.com/r/askscience/comments/g7um8/does_this_mean_days_were_shorter_while_dinosaurs/ | {
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"If this guy were a drug that is so lethal to your mind because you risk immense mind blowing (tantamount to the Big Bang going off in your mind every microsecond) then i would take 2 pills... daily.",
"Yes, I feel I have read a 23 hour day; the moon was also about 1/3 as big",
"I can't remember exactly where I've heard this, but apparently for awhile people thought the ancient Greeks/Mayans were slightly off in their astronomical calculations. Turns out a year was just very slightly shorter back then, so their math was off a bit from ours. ",
"Yes. The day was shorter in the Mesozoic.\n\nFrom Day article in Wikipedia...\n\n > The Earth's day has increased in length over time. This phenomenon is due to tides raised by the Moon which slow Earth's rotation. Because of the way the second is defined, the mean length of a day is now about 86,400.002 seconds, and is increasing by about 1.7 milliseconds per century (an average over the last 2,700 years). See tidal acceleration for details.\nThe length of one day was about 21.9 hours 620 million years ago as recorded by rhythmites (alternating layers in sandstone); when the Earth was new about 4.5 billion years ago, it probably has been around six hours as determined by computer simulations.\n"
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6svs3a | how do investors who invest into apps like snapchat make their money back? | Hello. So I want to venture into business so I am currently doing a lot of research. I want to know why so many people invest into snapchat and pour millions of dollars into it. What makes snapchat inc worth the billions of dollars it is proclaimed to be? How do these investors make their money back after investing large sums of cash into it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6svs3a/eli5how_do_investors_who_invest_into_apps_like/ | {
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"This is a bit long to explain, but I'll try to keep it as simple as possible.\n\nImagine Snapchat as a bigass pie. An investor will buy up a percentage of that pie. As Snapchat grows, each piece of its pie will grow and become more valuable. However, the investor still owns the same percentage of the pie.\n\nSo, because each piece is worth more, that means he's made a profit, right? Not yet - on paper, he has. To actually make (or \"realize\") a profit, he has to sell his percentage/piece (called a \"stake\"). In the business world, investors have three options for selling their piece of pie and receiving cash:\n\n1-Sell to another investor. The investor may contact an investment bank to find another pie eater, or may have a friend looking to buy a piece. Once he sells his piece and receives cash in exchange, he has made or \"realized\" his profit.\n\nNow, if an investor thinks the Snapchat pie could grow even more, he may want to hold on to part of his piece. He doesn't have to sell the whole thing.\n\n2-He can \"cash out\" or sell his piece back to Snapchat. To understand this, you have to understand what Equity in a company is.\n\nAll of the things a company owns (cash/equipment/inventory/supplies/property/intangibles) are called \"assets\". To get these assets, a company needs to borrow money (\"liabilities\") or sell a stake in the company (\"equity\"). Using cash, a company has to pay back what it borrows before paying owners. This means that equity can be thought of as the assets owners have a claim to once all debts are paid.\n\nSo, when cashing out, an investor will sell his piece/stake of the pie (\"equity\" in Snapchat) back to Snap corporate, and receive cash (an \"asset\" of Snapchat) in return. Snapchat may favor this if they think the company will continue to grow, and can take on debt or sell pieces to more people (see option 3) - the more of the pie that Snap itself sells, the more cash the company receives. So, it may want to own more of its own pie.\n\n3-Initial Public Offering (IPO) - if there is enough interest, Snapchat and its investors will split their pieces into even smaller slices (called \"shares\") and offer them to individual investors on the open market. Now, if Snap sells some of its shares, it will receive the cash. But, if an investor sells shares from his piece, he gets to keep the cash.\n\nLet me know if this is clear enough, or if you have any other questions. Hope this helps! \n\nEdit: formatting, on mobile and can't preview"
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de44zl | What are instances in which candidates for the American presidency attempted or obtained assistance from foreign powers to win the election? | For example, were there any interactions between Nixon's campaign of 1968 and the North Vietnamese, or the Reagan's campaign of 1980 and the Iranian revolutionaries holding Americans hostage? Or perhaps other examples? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/de44zl/what_are_instances_in_which_candidates_for_the/ | {
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"I cannot answer this in full for all US elections because that is not my field of knowledge.\n\nFrom my own field however, I can say that in the 1968 US presidential elections, the Soviet Union tried to interfere in it. Initially the Soviet ambassador was instructed by the Soviet Foreign Ministry to offer Democratic candidate and Vice President Hubert Humphrey any kind of help he asked for, including money. The offer was made at an informal dinner between Humphrey's family and that of the Soviet ambassador. The ambassador was however careful in his formulations so as not to cause a potential diplomatic scandal.\n\nThe Soviets feared Nixon as an anti-Communist Hawk, while the Kremlin had set as its goal to reach agreements with the US. The domestic prestige of the new Soviet leader Brezhnev was thus at stake to get an agreeable president elected.\n\nThe KGB in the meantime had established contact with the Nixon campaign through Henry Kissinger. Working as academic and foreign policy advisor to Nixon, Kissinger was approached by a Russian reporter for the Novosti Press Agency, Boris Sedov. Russian news reporters were more often than not a cover for KGB officers. Sedov knew Kissinger from before he entered politics, but now made use of this contact to obtain information on Nixon's intentions towards the USSR.\n\nWhen Kissinger hinted that Nixon was pragmatic and that his anti-Communist rhetoric was just rhetoric. Kissinger was probably aware that the reporter was linked to the KGB, and Nixon probably instructed Kissinger to pass on his willingness to improve relations. Several unofficial letters expressing mutual willingness to cooperate in the future were sent between Nixon and Brezhnev through Sedov and Kissinger. These contacts lasted for several months.\n\nRecommended literature & sources:\n\nAnatoly Dobrynin, \"In Confidence: Moscow's Ambassador to America's Six Cold War Presidents\"\n\nOleg Kalugin, \"Spymaster: My Thirty-two Years in Intelligence and Espionage against the West\"\n\nChristopher Andrew & Vasili Mitrokhin, \"The Sword and the Shield: the Mitrokhin archive and the secret history of the KGB\""
]
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|
40nl6b | Do men and women have mental/psychological traits that occur on average more for their respective sex than the other? | I had a conversation with a friend of mine yesterday regarding the idea of a male and female brain. I don't think any traits are going to be exclusive or always present for either sex, but I do think that on AVERAGE women enjoy certain activities, products, etc more than men and vice versa. Also I wanted to ask if any of these traits are the result of biology. | askscience | https://www.reddit.com/r/askscience/comments/40nl6b/do_men_and_women_have_mentalpsychological_traits/ | {
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" > Also I wanted to ask if any of these traits are the result of biology.\n\nTwin studies show that a part of our personality is determined by our genes. Identical twins reared apart are about as similar, in personality traits, [as twins reared together](_URL_0_). \n\nAnd as to differences:\n\nFor example, little males and females like to play with different kinds of toys, and this is apparently due to [prenatal exposure to male hormones](_URL_1_).\n\nThis is culture-independent, and apparently also extends to other species [such as rhesus monkeys].(_URL_2_)\n\n",
"_URL_1_\n\nThis article covers a recent paper about a this topic. The short answer is, it's complicated and our brains are extremely variable. Our brains are made of a complex set (the authors use the word \"mosaic\") of different elements, and some of these individual elements are indeed statistically more common in males or females. However, each individual brain is made up of tons of these elements, and some will come from the \"male\" end of the spectrum, some from the \"female\" end of the spectrum, and a lot will come from somewhere in the middle. This means that very few brains have only elements that all (or even almost all) come from one end of the spectrum, meaning that there is nothing that we can point to as a \"typical\" male or female brain. Essentially, there is so much variation within each sex (as defined by genitals), and overlap between them, that it's not very useful to categorize brains into distinct \"male\" and \"female\" classes.\n\nHere's a link to the original paper if you have access. The paper is quite good, relatively well written, and has an interesting experimental design.\n_URL_0_"
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"http://press.endocrine.org/doi/abs/10.1210/jc.2001-011531",
"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2583786/"
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6q19if | how much of humanity's creation accounts for earth's mass? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6q19if/eli5_how_much_of_humanitys_creation_accounts_for/ | {
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"Pretty much none of it. One way of looking at it is to consider a globe with accurate raised mountains. But in fact, if such a globe were the size of a china teacup, it would be smoother than the cup. So our structures are as nothing. OTOH, our pollution can affect the thin layer of life on the surface, and that's important to all of us. ",
"All human made objects are estimated to weigh 30 trillion tons, which is a lot, but minuscule compared to the weight of the earth: 5,972,000,000,000,000,000,000 tons. It's about one billionth.",
"None. Everything we've built came from the Earth to begin with. You can't create or destroy mass so everything we've made weighs the same (in total) as the raw materials they were made from. \n\nIf anything, the Earth is lighter since humans came along. We've built spacecraft and other things and thrown them off the surface of the Earth in to space. "
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4kds8x | Where did the idea of signing one's name for approval of a contract (even for minor things like delivery of goods) come about? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4kds8x/where_did_the_idea_of_signing_ones_name_for/ | {
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"Adding on, were there any methods of verification that a signature was from who it said it was?"
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3yuf3u | why do police body cams have such bad quality when camera's like gopro's are so cheap? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3yuf3u/eli5_why_do_police_body_cams_have_such_bad/ | {
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"it's about how long you plan on recording. \n\nhow many gigabytes would you need to record on your gopro for 8-12 hours? i bet that's a lot more than the size of the card you have. ",
"GoPro's aren't the cheapest cameras you can buy, for an up-to-date model thats ~$400 and going back to the original Hero that's still ~$150. Doesnt seem like much, but your multiplying that cost by every officer you could potentially have deployed at any time. So a small town, maybe 20 cops decked out with original Hero's, thats $3000 in just the camera hardware. More cost is involved in other equipment (cases, harness, storage, replacements) training the officers, maintanence, processing and storing the footage.\n\nThen comes the other point of file size. In a day, one officer could get something like 8hrs of footage. Unless you have really large storage mediums (ie, expensive) you cant record in high quality locally. Then once all 20 officers come back and hand in their cameras, you now have too store 160hrs of footage which is not insignificant. Chances are when the footage is ingested it is transcoded to lower its file size sacrificing quality again, because storage costs money.",
"They are crap in low light situations and need external batteries for longer than a few hours.\n\nCameras record better in low light when they have a larger sensor and night vision capabilities. GoPros have very small sensors and while they record beautifully in the day, not all altercations take place at 2 pm outside on a sunny day. The larger the sensor, the more expensive the camera gets. Add night vision and it gets more expensive. Now add the external battery packs needed to power the extra features and your cost continues to increase. ",
"Everyone has been discussing technical limitations however the likely answer is actually much worse. There are plenty of cameras with much better video quality available. When a municipality or county needs to buy something over a set dollar amount usually a couple thousand they have to go to competitive bid. Here they lost out exactly what they want and the specs they are looking for. In this case a police body camera capable of recording and storing video for say 12 hours. This gets published and then every seller of whatever you sent out for bid gets to send you a proposal of what they can offer and for how much. \n\nThe trick is when you get all these proposals back there's usually a pretty big price difference between the cheapest and most expensive. Obviously the organization ordering in this case the police want the nicest which usually is the most expensive. The town council or county commissioners however usually pressure you towards the cheapest. More times than not you end up with something towards the cheap end that while it works isn't the best option on the market. ",
"Go-pro's are cheap...?"
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6d9wx1 | How did Nikita Khrushchev survive Stalin? | I watched Bob Hoskins play him in the film enemy at the gates, I'm not sure how accurate a portrayal it was, but I'm still curious as to how he managed to keep his head down at a time when Stalin was executing so many senior officials | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6d9wx1/how_did_nikita_khrushchev_survive_stalin/ | {
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"From [an earlier answer of mine](_URL_0_)\n\nThe size and scale of the Great Purges sometimes obscures some of the subtleties of the Soviet system and the nature of political power under Stalin. While the Purges appeared to outsiders- both at the time and since- to be a case of the Revolution eating its own, the senior Bolsheviks purged tended to come from internal factions within the Soviet system. A number of the \"Old Bolsheviks,\" ie veterans of the pre-1917 political world, survived the Purges. Anastas Mikoyan and Lazar Kaganovich were certainly rather senior members of the Politburo and both survived. Stalin himself played a dynamic role in the course and micromanagement of the purging of senior CPSU members. These dynamic of the Soviet state gave some individuals in Stalin's personal entourage a modicum of security all while fueling the the Purges excesses. \n\nOne of the facets of Stalin's dictatorship was that by the early 1930s he had accrued a constellation of hard-nosed administrators and servitors. Stephen Wheatcroft memorably coined the phrase \"Team Stalin,\" to describe these individuals. Some of them had been junior members of the RSDLP and had come to prominence during the Revolution and Civil War, which in turn led them to a position within the nascent Soviet bureaucracy. Both Khrushchev and Molotov fit this mold; both men were what would be termed in the West as \"upwardly-mobile\" within the Soviet state. They were were relative late-comers to the RSDLP but rose up through the ranks during the Civil War and Lenin years. This naturally meant these men were drawn into Stalin's orbit. Stalin's political maneuvering after Lenin's death capitalized on his control over the bureaucracy to sideline his other rivals among the senior leadership. Still other members of the Team were Stalin's early political allies like Kaganovich or Kliment Voroshilov. These men not only capitalized on a close personal relationship with Stalin, but were also important allies for Stalin's emerging dictatorship. The aged Mikhail Kalinin, for instance, struck the correct image of a senior peasant elder within the Politburo. Although he was relatively toothless in terms of actual power, only Stalin received more personal petitions from Soviet citizens than Kalinin. The Team had proved essential in implementing both collectivization and the Five Year Plans, as well as attempting to restore something of a Soviet diplomatic presence within Europe. Stalin may have a strong tendency to micromanage, and this was one of the sins Lenin faulted Stalin in his Testament, but a micromanager needs someone to carry out orders. \n\nThe problem with this semi-open clique leadership is that it puts those outside the group into an anomalous position. They have less real authority, but still exist within the system. Trotsky's purging and exile often obscures the fact that many of Stalin's political opponents of the 1920s remained within the USSR, often in some form of official capacity after a suitable supplication to Stalin. Both Zinoviev and Kamenev were in neutered political positions until their formal expulsion from the Party in 1932. Stalin himself saw these super-attenuated members of the Party as dead wood and they were ready scapegoats for the failures of the 5YPs and other problems with Stalinist state-building. Both in private and in public, Stalin would rail against the old-style thinking and lack of energy devoted to the Soviet project and characterized these sidelined individuals as exemplars of this problem.\n\nThe emergence of the Team as well as a whole generation of young managers from collectivization and the 5YPs created a dangerous nexus that made the Great Purges so destructive. Not only did Stalin fear that his rivals could unite and dethrone him, he also had at his disposal a collection of servitors willing to advance their careers at others' expenses. For the Team, this meant ferreting out real or expected enemies. More often than not, they often targeted outsiders. Of the Politburo members purged in 1937, they were relative outliers within the larger Soviet system. Most were late-comers to the Politburo and a number of them had been abroad for reasons of health, providing a neat pretext for charges of foreign collusion or connections to Trotsky. Other out-groups were especially vulnerable to the purging process. There was a strong distrust within the early Soviet system of military professionals. As good Marxists, a number of the inner circle appreciated the lesson of the French Revolution where Bonaparte used the army to put an end to the revolutionary process. Adding to the fears of Bonapartism, many officers of the first decade of Soviet rule had ascended the ranks semi-independently of the Party, and, by extension, Stalin. These suspicions bore fruit during the Great Purges as military officers found their personal networks within the military provided very little cover against charges of treason and wrecking. \n\nBut being on the Team always carried with it an element of risk. Displeasing Stalin or creating some sort of pretext for removal was an ever-present threat during the Purges. Genrikh Yagoda's fall exemplified that no one was immune from the process. Yagoda, as head of the NKVD, was notoriously corrupt and inefficient and enemies within the Team and the NKVD used this against him. His successor, the much younger Nikolai Yezhov, conducted his duties with far greater probity and thoroughness than the venal Yagoda. But although Yezhov was a more efficient executor, that very status painted a target on Yezhov's back. Like many intelligence chiefs, Yezhov actively sought out intelligence on his political rivals. Such files were dangerous in the collective paranoia of the Great Purges as trivial biographical details and missteps could become treason. Stalin's habit of simultaneously delegating and then micromanaging the Team gave Yezhov plenty of evidence on the Teams' activities that could be spun into a charge. Not surprisingly, Yezhov was the most powerful member of the inner circle to be purged. Even here, the purging process was quite different and staged with a gradual stripping of his power before his arrest, show-trial, and execution. A similar fate befell Yezhov's successor Beria after Stalin's death, illustrating the occupational hazards of being Stalin's chief of secret police. \n\nAlthough underlying causes of the Great Purges are still highly contentious within the historiography, the process of the Purges was relatively straightforward. Much of the initial targets were outliers and men who had lost earlier political battles with Stalin and were thus automatically suspect. But as the Purges escalated, blame-shifting and circular firing squads began to take over, leading to a wider expansion of arrests and show trials. Stalin proved an important bellwether for the Purge process that encouraged to evolve in certain directions or occasionally putting a stop to it in some areas. The Team had been used to tailoring data to suit Stalin's expectations for the better part of a decade before 1937 and the Great Purges were not an exception to this phenomenon. Yezhov in particular knew how to play to Stalin's instincts and suspicions and it was this that made him especially dangerous to other members of the Team. While some members of the leadership participated in the Purges as a matter of self-preservation, others like Yezhov or Khrushchev used them as an opportunity for career advancement or to settle scores with their rivals. While the Terror certainly disrupted the Soviet leadership, it also created opportunities for advancement and bound certain members of the Team together with their master. By fusing self-preservation and careerism, the Stalinist system of government created a self-perpetuating dynamic that only Stalin could put the breaks upon. \n\n*Sources*\n\nFitzpatrick, Sheila. *On Stalin's Team: The Years of Living Dangerously in Soviet Politics*. Princeton: Princeton University Press, 2015. \n\nGetty, John Arch, Nadežda Vladimirovna Murav'eva, and Oleg Vladimirovič Naumov. *Yezhov: The Rise of Stalin's \"Iron Fist\"*. New Haven: Yale University Press, 2008. \n\nKhlevniuk, Oleg. *Master of the House Stalin and the Inner Circle*. New Haven: Yale University Press, 2009. \n\nWheatcroft, Stephen G. \"From Team-Stalin to degenerate tyranny.\" In *The Nature of Stalin’s Dictatorship*, pp. 79-107. Palgrave Macmillan UK, 2004."
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3w7o3r | Has any major political candidate before ever advocated the prohibition of people of a certain religion entering the United States? | Tonight on *The Rachel Maddow Show*, Rachel claimed that Donald Trump's proposal was the first time any major party Presidential candidate has proposed banning entry to the USA on the basis of religion. Is this true? I would think that the idea had been floated before, perhaps about Jews or Catholics.
EDIT: Later in the show she did qualify her statement to "modern" political history. I am still interested in the answer throughout American history though. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3w7o3r/has_any_major_political_candidate_before_ever/ | {
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"I've been thinking about this a lot for the last couple days since I heard about some of the things Trump said. I've wanted to respond since seeing your question but I've refrained because I think it will be hard for me to answer without getting pretty close to violating the 20 year rule.\n\nI'm going to try anyway.\n\nI'd like to bend your question a little bit, because there's an analogous situation to this in American history that I just can't stop being reminded of. It's not a religion, but it's a very similar situation. The discourse you're hearing today is very much like what was being said in the late 1800s and early 1900s related to Chinese immigration. Yes, Chinese isn't a religion, but humour me and the parallels will become apparent.\n\nOne of the most significant and often cited reasons for why \"they\" should be excluded has to do with their inability to assimilate to \"our\" way of life. You find this brought up again and again during this time by journalists, lawmakers and those employed to enforce the laws (and create a few of their own in the process).\n\nQuoting here from *To Be an American: Cultural Pluralism and the Rhetoric of Assimilation* by Bill Ong Hing\n\n > An important element in the anti-Chinese crusade was doubt that they could successfully assimilate into American society... As immigrants, the Chinese posed the first serious threat to the melting pot concept. They were believed to be immutable, tenaciously clinging to old customs, and recalcitrantly opposing progress and moral improvement.\n\nThat should sound familiar. The manufactured thread of obedience to the Emperor kept people scared despite not actually being an issue. The manufactured thread of Shari'a is a good analogy.\n\nQuoting here from Erika Lee's *The Chinese Exclusion Example: Race, Immigration, and American Gatekeeping, 1882–1924*\n\n > While Chinese were considered to be biologically inferior due to their status as heathens and their alleged inability to assimilate in an Anglo-American mold, Mexicans were degraded as an ignorant “hybrid race” of Spanish and Indian origin.\n\nPutting aside the at-that-time very-trendy Social Darwinism, this too has clear parallels. They^1 will not conform to our way of life, they do not follow our God. Thus they should not be accepted.\n\nOne more quick quote, this time from Erika Lee's *At America’s Gates Chinese Immigration During the Exclusion Era, 1882-1943*:\n\n > the witnesses continued to emphasize how Chinese were ‘‘permanently alien’’ to America, unable to ever assimilate into American life and citizenship.\n\nThis was an incredibly important point for people. The eternal foreignness of the Chinese was pivotal to the discussion. This became a major issue not just for immigrants, but for native-born Americans of Chinese descent. There were calls to deport even those that had been born in the states and, in accordance with the 14th amendment, were unquestionably American. Except that it *was* questioned, and often.\n\nVery often, American citizens found themselves being questioned and their credentials being doubted by a system that was intent on removing Chinese from America's shores. At the time this was often based on their language ability and other superficial factors like their dress, the idea being that anyone born in America would be able to speak English just as well as white people.\n\n* \"But Islam isn't a race\" / \"But Chinese isn't a religion\"\n\nSo now I want to get to a point that gets brought up a lot in modern debates and bigotry-apologetics. You will hear people say that they can't be racist because Islam isn't a race. The problem with this argument is that \"racism\" isn't mean't as strictly \"racism\" but simply as bigotry, since the whole notion of race is ultimately a social construct anyway. Here too there are some clear parallels between the situation you bring up and that faced by Chinese-Americans and prospective Chinese immigrants during the exclusion period. The notion of \"Chineseness\" was ever-shifting such that it no longer followed the lines of traditional racial categorisation.\n\nOne notable case of this is that of Lawrence Klindt Kentwell who had been born to a Chinese mother and a British father in the Commonwealth, who had attended Columbia University Law School and who was living in Honolulu. He would regularly get waived through by immigration officers because he looked white. As things progressed and the enforcement got tighter, he too became a target of the policies. Another biracial American, Ms J Morton Riggs, faced similar scrutiny, despite her mannerisms, dress and all outward expressions of culture being that of a white American. One again the notion of being unassimilatable comes up.\n\nOne more point I'd like to bring up. During this period, as today, there were efforts by members of the maligned community to draw distinctions between themselves and the \"bad apples\". Any previously existing lines of solidarity dissolved in time, as members of the community began to distinguish themselves from the undesirable members of the larger community. There wasn't the thread of terror, but the notion that \"our way of life is under attack\" was very much present. This all began as a resistance to manual labourers \"taking our jobs\" in the mid-to-late 1800s in places like California and Hawai'i, but it quickly became a bigger issue that dictated national policy, and it was the very foreignness of the Chinese and the growing Yellow Peril mentality that allowed things to develop to such an extent that California was effectively calling the shots on National immigration policy.\n\nAdditionally, if this is in fact the first time that a religion has been the sole defining cause for limiting immigration, that too has a clear parallel, as the exclusion period was the first time that 'race'/nationality was the sole defining cause for limiting migration.\n\n* Has any major political candidate....\n\nYes, again with the caveat that it's not actually a religion: During this period most major politicians including sitting presidents supported prohibition and often deportation. Letters to the president/s by those with grievances often fell on deaf ears (blind eyes?), and in the early stages of the exclusion period it was *only* that the policies were in violation of the Treaty of Tianjin that in 1880 it was not supported, but then of course two years later the treaty had been amended specifically to allow for what became the Chinese Exclusion Act.\n\nFinally, one more aspect of the historical scenario which merits repeating. Quoting here from Qin (cited below) relaying an 1878 address to the House Committee on Education and Labor on February by Joseph Kennedy:\n\n > Kennedy also emphasized that the Chinese were not Sabbath breakers, criminals, paupers, ballot-box stuffers, Molly Maguires^2, or conspirators against the public schools. Then turning to the charge of nonassimilation, he argued that the Chinese would assimilate with Americans if they were kindly treated, but the desire to assimilate would undoubtedly vanish like smoke if they were maltreated.\n\nThose who cannot remember the past are condemned to repeat it.\n\n**Infallible Mods:** Let me know if I should reign in the modern connections. I'm not attempting to give an analysis of modern events, but rather just to show how the historical situation should be familiar to subscribers.\n\n**Sources:**\n\n* Hing, Bill Ong (2000) *To Be an American: Cultural Pluralism and the Rhetoric of Assimilation*. New York University Press.\n\n* Lee, Erika (2002chinese exclusion) The Chinese Exclusion Example: Race, Immigration, and American Gatekeeping, 1882–1924. Journal of American Ethnic History.\n\n* Lee, Erika (2003) At America’s Gates Chinese Immigration During the Exclusion Era, 1882-1943. University of North Carolina Press.\n\n* Mar, Lisa Rose (2010) *Brokering Belonging Chinese in Canada’s Exclusion Era, 1885–1945.* Oxford University Press.\n\n* Qin, Yucheng (2009) *The Diplomacy of Nationalism the Six Companies and China’s Policy Toward Exclusion*. University of Hawaii Press.\n\n* Zeller, Theresa J (2013) *The Chinese Exclusion Act of 1882 and Hawaii*. University of Washington Tacoma.\n\nI'm probably forgetting some other source I looked at while typing this so I may have to edit to add it in later.\n\n**Footnotes:**\n\n1. I'm referencing the views of the time here, not speaking for myself.\n\n2. [Molly Maguires](_URL_0_)"
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2wlvau | Do viruses evolve? | I know that there really is no consensus as to whether or not viruses should be considered living things, but they do have a way of replicating. This leads to me wondering whether they are capable of evolution. | askscience | http://www.reddit.com/r/askscience/comments/2wlvau/do_viruses_evolve/ | {
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"Yes viruses do evolve. Evolution is the result of random modifications of the DNA sequence. These errors occur due to several factors, e.g. while the DNA is replicated to create a copy of the original virus. \n\nTheses errors occur in viruses as they occur in other cells and organisms. If such a error is beneficial to the virus, e.g. making it more resilient to the immune system of the host, it will be carried on to the next generations. Thus a virus can evolve.",
"Not only viruses evolve, but because of a very short generation time they are the fastest evolving group of organisms. Just to compare, human generation time is approximately 20-30 years. For a flu virus it is 6 hours. So, for one human generation a flu virus will have ~ 30000 generations (assuming that no immune system that cut this insanity short exist). This, is not even the fastest one. Phage T4 that infects bacteria does in in 20-30 minutes, and then there are viroids that replicate in under a minute."
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5t1lf7 | why do poorer people tend to have more children? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5t1lf7/eli5_why_do_poorer_people_tend_to_have_more/ | {
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"There's a number of factors.\n\n1) Below a certain threshold, even small amounts of money matter. If I have plenty of money, having a stash of condoms (or if female, taking birth control just in case) is relatively easy to do. If putting that money towards birth control means I may have to skip a meal, then I may be more likely to risk pregnancy.\n\n2) There tends to be educational gaps, and I've actually known people who honestly didn't understand what causes pregnancy, so them not taking steps to prevent pregnancy makes more sense.\n\n3) Anecdotal, but possibly related. I've been broke before, and it tends to go hand-in-hand with a \"meh, fuck it\" attitude, at least for me and a lot of the people I know. At some point you just expect life to hand you shit, and there's only so much shit-ade you can make, so you stop taking basic measures to prevent bad things\n\n4) Abortions cost money, which ties back into #1.\n\n5) As someone else pointed out \"when you're poor, there's not much else to do.\"\n\nThere's probably a lot more contributing factors, but I suspect the above will account for the majority of the cases.",
"Wealthy people save for their retirement.\n\nPoor people plan to have at least one of their kids take care of them, financially and also as an alternative to a retirement home.",
"This may be controversial but some people are just not great at making decisions for one reason or another. If you are not someone that made great choices like studying hard and working hard you are probably poor. You probably are not super responsible with your birth control or general life planning. Another factor is that if you are super focused on your career then you will tend to be richer. You will also probably have to wait to have kids until you are older which means you will have less of them. Again, these are all broad generalizations but more often than not the traits that make you rich correlate to the traits that make you more responsible when planning your family.",
"I believe it's more that people focused on gaining financial ground and stability put off having children right away. They spend their 20's in college and building a career instead of focusing on having children. \n\nFor instance, those who want to become a doctor, lawyer, vet, college professor, or advanced business profesional etc. require advanced degrees which will take one into his or her mid-to-late 20's and sometimes a little longer. And then one needs several years to establish a career in a chosen field. \n\nA female's reproductive years are only so long. Most people don't want to still be parenting youngsters in their 50's and beyond, so they choose to procreate in the 30's and stop before their early 40's. In a decade or less, with reasonable age separation, you have have 2 to 3 kids... maybe 4 if you are pushing it. \n\nBasically, more successful people want to go to school, establish a career, get their finances in order, get married and then work on a family. But people who are less well off have a different mind set and don't have a career or nest egg; they have a job that they more than likely fell into and live paycheck to paycheck. If they get married, it's often small and inexpensive. More often than not, they have kids, then (maybe get married) and then worry about their finances (making ends meet) after they have already established several kids. \n\nWhen you add in an entire extra decade of child baring into the equation, that means that you can pop out a heck of a lot more kids... anywhere from 4 to 12. \n",
"A lot of it comes down to women's rights. Poorer communities tend to place women in more traditional roles, where much of their value is determined by having children. When women have more control over their lives, they tend to choose when and whether they have children.\n\nSuch societies often give women perverse incentives to have more children. Discouraged from pursuing careers, they need a man to take care of them and having a child with that man means they are more likely to stick around.\n\nFinally, some it comes down to money and education. Birth control isn't always cheap, can require medical assistance, and discipline and knowledge to use effectively. If you don't have health insurance, never got more than a high school education, and live in a society where \"good girls\" don't talk about sex to their doctors or pharmacists, you might not be good at birth control.",
"Tax exemptions. Less wealthy families see it as a way to evade taxes and also be entitled to a \"refund\" when tax time comes around. Also, some see it as a way to be guaranteed income as the children in poverty or near poverty will most likely be subject to belonging to a divorced parent or one that never marries and as such will benefit from child support.",
"Really simple answer - more children costs in the short run but in poorer countries without labor laws they provide income over a longer time horizon. Especially in agricultural societies where more children = more farmhands. People on here seem to think it has a lot to do with birth control availability.. That may be true in the first world. But even before the advent of birth control, poorer people had more children. Correlation doesn't always equal causality. ",
"there's no one reason...I can think of several off the top of my head\n\n* children actually help support you in the long run, yes they cost money to raise but they support you when you are old and/or sick (hopefully) especially relevant if you are farmers or manual laborers. Kids are the poor man's retirement fund\n* less access to birth control/abortions\n* poorer women tend to be less educated and have less economic power, so they may not be aware of birth control options or may not feel able to stand up to their husbands/boyfriends. The more education a woman has, the fewer children she is likely to have.\n* women may have children in the hopes of maintaining a relationship with a straying partner\n* many poor women have few relationships and children can seem like a way out of loneliness",
"1) Poor people are unlikely to be able to afford more effective forms of birth control, especially if they are un- or underinsured. I'm fortunate to have a good-paying job with health insurance that covers HBC and my IUD, which cost $1200. Someone who works a job that pays poorly is unlikely to have these benefits, and is *definitely* not likely to be able to pay out of pocket.\n\n2) Many poorer communities do not have proper sex education - hell, many schools regardless of socioeconomic status don't. It's difficult to prevent pregnancy if you don't understand how the body works to begin with. That, and many poor communities tend towards more religious/conservative values, which don't often encourage birth control and sex education. It's unlikely that a person who grew up knowing nothing is going to be able offer this crucial knowledge to their offspring. I can only imagine what it'd be like to hear the same bullshit I heard in high school, but with parents who they themselves do not know enough about the subject to correct me.\n\n3) Abortions are not only hella expensive, but very difficult to get in most states - and, you guessed it, even more so in poor communities. I can put in for time off work for a doctor's appointment and use sick time without worrying about being fired. I can call off work if I'm sick without fearing that I'll lose my job. Many poor people, however, may work jobs that do not provide sick time, and there's a very real fear that it would ultimately boil down to wondering if they could truly afford to lose their job over this. An abortion isn't just an in and out visit, in many places.\n\n4) Conservative/religious values that dictate gender roles; for some people, women are inherently meant to be mothers, and bearing children is the greatest, single most important thing a woman can do. ",
"The points mentioned in this thread pretty much encompass all the reasons for poor people having more children. \n\nHowever, I would further like to add two more points from a South Asian perspective-\n\n1. Poor folk tend to have more children as it guarantees that there will be more hands available for work, hence contributing towards the financial stability of the family. \n\n2. Since poor people don't get access to proper education, orthodox beliefs are rampant. This causes them to yearn for a male child (males provide for the family, whereas a females marry into another family), hence keeping on having kids until they have one. ",
"In college we had this sociology class where the professor talked about this. One of the answers that made sense was \"Poor people tend to have more children because they think that having more children will mean more people will be supporting them or their whole family in times of need. Whether it be during their old age or during times of illness and etc\"\n\nThis is an opinion and I believe it is relevant to this topic so I brought it up.",
"I just want to chime in with a personal observation here. In my own experience, it seemed like a lot of poorer women - even as young as high school age - would seek romantic and sexual relationships as a means of escape from troubled home and family lives. In contrast, better-off young women would only seek relationships when they felt they added to an otherwise emotionally positive life. I definitely wouldn't go as far as to accuse poor women as a category of seeing pregnancy as a means of securing a relationship; it just seemed - again, in my observation - that they were more likely to have sex earlier and feel they really needed to constantly be in relationships.\n\ntl;dr seems like poor women have more sex due to lack of positive family relationships \n- > more babies",
"Same reason people masturbate when bored. There's nothing to do. People with money tend to stay occupied and have things to look forward to.",
"All of these reasons listed here are surely contributing factors but I haven't seen anyone get to what I'd consider the root of the answer. \n\nI'd say it's all about \"Instant Gratification\" vs. \"Delayed Gratification\" (aka the Marshmallow Test). \n\nThe same type of people who would habitually spend every dime they earn before the week is out so they can never dig their way out of the hole are going to be the same type of people who are thinking short term during sex and go unprotected. ",
"As mentioned by many others, there are multiple reasons, such as a low standard of education due to the incapability to go to school, little knowledge of contraceptives due to, well, the incapability to go to school too, too poor to use contraceptives and abortion etc...\n\nHowever, the first reason I thought of was actually J.C. Cadwell's Theory of Intergenerational Wealth Flow. Indeed, children cost money to raise. The more children one has, the more money one needs, thus poor people have more children; seems paradoxical as you observed. However, you are not taking into account where that 'money' comes from. Is it from the parents' pockets or the children themselves? In other words, if the children are able to contribute to the family, then having many children isn't a very big problem at all. Sure, toddlers wouldn't be able to contribute much, but when they reach an age capable of doing manual labour, they can start paying off their 'debt' by helping the family.\n\nBut there is another part to this theory. What kind of society are we talking about? Less-developed countries, or developed countries? In less-developed countries, children are valuable assets who can help their parents with housework, such as tending to the livestock. Wealth flows from the children to the parents (hence 'Theory of Intergenerational Wealth Flow). However, in developed countries where the cost of living is high, a child may not be able to pay of one's 'debt' no matter how long he works for. Wealth ultimately flows from the parents to the children. Your question title doesn't state which society you are talking about, but since you mentioned America (which I assume is largely a developed society, maybe less-developed for some rural areas; I don't live in America) in your description, the reasons why poorer people have more children are probably the other reasons mentioned (e.g. lack of education).\n\nMost of us live in developed societies, so we tend to assume that 'having children = expensive', which is mostly correct ONLY in developed societies. In less-developed societies, which tend to be poor, having children can be an asset.\n\n*(I'm not sure if this answer is ELI5 standard :c)*\n\n**tl;dr Children in poor families tend to be from less-developed societies where there is a low cost of living, thus instead of being a burden on the family, they can be an asset to the family by contributing back to the family and offsetting their burden when they are of a capable age.**",
"Childre gives them purpose and meaning in they life. It's all about priorities. They get happiness having children but the rich are interested in the biggest house the fastest car the fame the position in society. Even though they don't have the among of money needed to rise them , however we do things that makes us feel good in the moment. \n",
"Because they do not let the amount in their bank account dictate whether or not to have children.",
"My experience is purely anecdotal, so take it at face value:\n\nI worked for HUD during the late 80s-90s in one of the poorest areas of the nation. 13-year old pregnant girls were brought in by the mothers to apply for housing. Consider their circumstances, though: as young, black, under-educated females without transportation or any job opportunities, who already lived in public housing with mothers who survived on welfare and cash gifts from \"friends\", a pregnancy/child meant a relative fortune in benefits: housing rights, Aid to Dependent Children payments, medical care, food stamps (of a sort), etc. Imagine going from being a poor black teen girl in a depressed rural area, with absolutely NO HOPE of anything better, and then the question is not WHY have children, but WHY NOT? As a normal human being with normal desires for intimacy, love, and family, this situation, no matter how abhorrent to someone in different circumstances, becomes the norm.\n\nEdit: should add that the area this took place in also had the highest per capita number of churches, and ZERO sex ed, and limited contraceptive availability, even if the girls had been educated about how to prevent pregnancy.",
"Having kids makes you poorer, so when we assess poor people with lots of kids maybe the tail is wagging the dog. Plus economic incentive, tax credit. Plus birth control cost being higher percentage of income means people don't buy it. Last part is why I'm in favor of full federal birth control subsidies. Will pay off in reduced crime in 13-20 years. ",
"I'd throw in that something being left out in most comments is parents perspective.\n\nIt's not always about benefits and housing. \n\nI look at mentality. People are wired different. People have different ambitions.\n\nMy family growing up, my parents always owned their own business, so about the time I turned 10 I saw my mom to get on the bus and occasionally would see them around 8pm-10pm at night. Their drive was less family oriented but for finances.\n\nMyself growing up mostly parentless from their job pretty much vowed I'd never own my own business and that my kids would get the majority of my time.\n\nI'm not well off by any means and I'm about to go into a different field (IT to nursing). But my gf and I have 3 kids between us and plan on having one more at some point. Because we want to have a big family. \n\nThe kids are not neglected, we are not on benefits, it's merely want we want. We enjoy being parents.\n\nI can't attest to the situation in urban areas as I live fairly rurally. So take that with a grain of salt.\n\nI do know people that have 8+ kids for benefits and I know some that have atleast 5+ that enjoy having a big family. So I think it really depends on the people.\n\nI do know that for the few benefit reaping ones drugs played a large part.",
"Many good reasons already stated in the comments.\n\nHere in The Philippines, it's a mixture of causes.\n\n1. Birth control being unavailable or seen as a luxury. \n2. Poor sex education. I've met 15 year olds with funny ideas about pregnancy or how to prevent it. (Like..if the girl eats certain foods afterwards or doesn't lie down for 3 hours then she can't get a baby).\n3. High infant mortality rate. Even basic medicines are out of financial reach for many. They refuse to go to hospitals, even for serious issues.\n4. Interference from the fucking Catholic church. Apparently God wants people earning $4 a day to have 10 kids.\n5. The hope that one of the kids will get a good job and be able to financially support the entire family. Families here will often pick the eldest girl or smartest kid and put them through school whilst ignoring the education of others. It's easier for girls to find work here. Filipino's focus on supporting their parents more than their children which helps continue the circle of poverty.\n6. Just not caring. So many guys here get girls pregnant and then disappear."
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hxxd2 | From how far away is evidence of humanity optically visible? | From near Earth orbit and our general area, we can see the lights of civilization at night. From how far away can we still distinguish humanity?
From Earth, Mars looks like a bright star. I presume we look the same from Mars. Have we changed Earth's albedo? Are we a brighter star than we were a thousand years ago? | askscience | http://www.reddit.com/r/askscience/comments/hxxd2/from_how_far_away_is_evidence_of_humanity/ | {
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"With the naked eye, or with an optical telescope of sufficient size?",
"I'm not a climatologist, but I'd wager we've only slightly increased Earth's albedo. This sort of question can be answered in relation to our search for extra-solar planets (planets around other stars)\n\nTo take an actual picture of a planet, you need to get reflected star light from it's surface/atmosphere, and effectively block out the star's light. The contrast ratio of an earth-like planet to a sun-like star in the optical is about 1:10Billion. That is to say, the star would put out 10Billion times more light than the planet would reflect, and you have to VERY carefully block its light out. In the IR the situation is a bit better, at only 1:A few Million. Check out this wikipedia page for more on that:\n_URL_1_\n\nNow to detect \"civilization\", you would need even more contrast, as we don't produce much light or heat. We're probably louder at radio wavelengths (think TV, radio, etc) but aliens would need to filter out the sun and Jupiter's radio emission... I haven't done that calculation, but now that I say that it I would be interested in seeing how \"loud\" we are at those frequencies.\n\nNaked-eye we would only be visible from probably a few million miles. On the moon you can see, with your naked eye, the APOLLO laser in New Mexico\n_URL_0_\nI worked at this observatory, and know the guys who run it. Suuuper cool project. They calculated that the green laser would look as bright as Jupiter on the moon to the naked eye. If you pointed that thing at Mars, and maybe ran at a few times higher intensity, you could probably see it w/ naked eye. This is the best example I can think of, short of seeing a nuclear explosion.",
"Astronauts took pictures of Earth from [Luna](_URL_0_); are you wondering if humans have become more evident since the late 60's? It seems like all you would be able to see is clouds. They reflect the most light on the planet. ",
"At most probably about 200,000 light years. That's how long we've been around.",
"at least about 116 AU. That is where the voyager space probe is, and you could see that if you were near enough to it."
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pmcbs | What would happen if something were to heal into a cut or scrape? | I have a scrape on my ankle on which the entire top layer of skin came off, so I covered it in antibiotic ointment, placed a piece of gauze over it, and wrapped some fabric tape around it. This was yesterday morning. This morning, as I tried to remove the bandage and gauze, some of the gauze had healed into the scrape. My mom made me run it under warm water and pull off the remaining gauze, which caused it to start bleeding (and hurting) again. She said leaving it on there would cause an infection.
**My question:** What would have happened to my scrape if I had never pulled the gauze off, and it had healed into it? Would it cause an infection even though I had it covered with oodles of antibiotic ointment? What if, instead of gauze, it had been some other substance or object? | askscience | http://www.reddit.com/r/askscience/comments/pmcbs/what_would_happen_if_something_were_to_heal_into/ | {
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"it won't necessarily cause an infection. bullets are sterilized by heat so won't cause infections, a few historical figures would have lived longer if doctors hadn't been so set on removing the bullet. Your case is less clear.\n\nabout what will happen to the object, I'm pretty sure that lightly embedded stuff will work its way out. this is what I believe has happened to splinters I have had. I'm not familiar with any process like that though, so someone else will have to give us a better answer for your second question.",
"I have a small pebble embedded in the palm of my hand. \n\nWhen I was a kid, I fell off my bike while speeding down a steeply angled gravel road. Landed palm first.\n\nThe pebble was way bigger than the wound. (They couldn't figure this out, assumed the impact was so fast that the skin stretched or something.)\n\nSo they would have had to cut open my hand, around lots of tiny nerves to get it out. They irrigated it for about a half hour, gave me some antibiotics. And told me to see if my body reacted to it.\n\nIt never did. 20 years later I can't tell it's there unless I press real hard around the tiny scar it left, then I can feel a small lump.\n\nSummation: Foreign bodies will only cause infection if not sterile. Wikipedia claims they can 'hide' infectious agents from the immune system (I had trouble verifying this.) but I don't think this applies to a few strands of gauss in the skin. They can, however, cause chronic inflammation by triggering a response from the immune system.\n\nSource: _URL_0_"
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6d034l | what someone can do with your ssn | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6d034l/eli5_what_someone_can_do_with_your_ssn/ | {
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"A person can do several things if they gain access to your personally identifiable information. The \nSocial Security Sumber (or Social Insurance Number in Canada) is connected with several aspects of a citizen’s life. If a hacker has access to it, the consequences can be disastrous for the person whose identity was compromised. These are the possible things that they can do with it:\n\n* **Apply for a loan or credit card**\n\n With a stolen social security number, a hacker can open a bank account in the victim’s name. The social security number is perhaps the most important information that a lender requires when processing a loan application. A thief who has access to that number and the name on the card can apply for a loan or get credit cards. When it is time to repay the loan, they won’t. This will damage your credit score because the missed payments will be linked to your number.\n\n On the bright side, by simply analyzing your credit reports and credit scores, you can easily spot fraud and stop it. However, your credit will not recover immediately.\n\n\n\n* **Get medical treatment**\n\n Someone who has access to your social security number can receive treatment under your name. This will taint your medical records. And if you receive medical care based on an incorrect medical history, you will have to deal with deadly consequences.\n\n\n\n* **Get tax refunds**\n\n Perhaps the best way to avoid this situation is to file your taxes as soon as possible. Your tax return will be rejected if a thief has already filed it in your name. This way, you can figure out if your card has been compromised. You can then explore ways to resolve the fraud and take steps to ensure that you receive the refund.\n\n\n\n* **Steal Your Benefits**\n\n The identity thief can also file for unemployment benefits using your social security number. This will deplete the assistance you might need later.\n\n\n\n* **Commit Crimes**\n\n The hacker who stole your social security number may have committed several other crimes as well. If he gets caught for his involvement in another crime and gives your number to the police, you will become entrapped in his criminal history.\n\n Thieves can use your identity for several years without getting noticed. Many of the crimes that they commit cannot be detected easily. Checking your credit reports regularly is a good way to detect unauthorized accounts. If you find anything suspicious, you should act immediately.\n"
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3tn7h4 | how is our brain able to accurately pinpoint the area of our body that is feeling pain or being touched? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3tn7h4/eli5_how_is_our_brain_able_to_accurately_pinpoint/ | {
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"You have sensory receptors all over your body and they are there to detect input and communicate that with the brain. When you are touched, that is input, and the receptors generate a message that travels to the spinal cord and then up to the brain. Your brain is like a map and has a region that deals with decoding sensory input. Basically, it can tell which set of receptors picked up on the input and sent the message, and therefore, where precisely the input came from. The signal goes here, you/your brain decides whether to act on that input, and if so, sends a message back down. \n\nInterestingly, some areas of the body have more sensory receptors and more area of the brain devoted to dealing with them than others based on function. Think about how important touch is. Your hands have a ton of tiny receptors because distinguishing touch is really important, and thus a paper cut on your finger hurts a lot. Your back, however, doesn't really need to be that great at touch, so if you were to poke it with something small, you might not be very accurate at pinpointing exactly where you were poked, and a paper cut probably would not hurt as much. (Google \"sensory homunculus\" for a better representation of sensory dedication in the brain.)\n\n(EDIT: changed \"decide\" to \"decides\" because presumably, you/your brain are the same and therefore a singular entity? I hope?)"
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246vkw | If I were to send a tree to mars with sufficient nutritients and water(everything it would need to grow on earth), would it be able to grow and produce oxygen? | askscience | http://www.reddit.com/r/askscience/comments/246vkw/if_i_were_to_send_a_tree_to_mars_with_sufficient/ | {
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"Nasa, among other groups with space exploration in mind, are asking that question themselves:\n\n_URL_0_\n\nIt seems the biggest problem to overcome is the low atmospheric pressure, which sucks the already rare water out of plants. Nutrients don't seem to be a problem.",
"My boss (PI, professor, mentor, etc), did some preliminary research on this [here](_URL_0_). They were looking at cyanobacterial growth in some Mars-like conditions. This was a bit before my time in the lab though. \n\nFrom the abstract, it seems nitrogen and temperature tolerance were some key issues that need to be addressed. \n\nI'm sorry I do not know more, as I said, this was sometime before I entered the lab. It was mostly done and performed by an undergraduate student, so if anyone is currently an undergrad, look for fun research projects!\n\nI did happen to come across the the Martian soil simulant medium one day in lab. It was a fun novelty in a NASA bag, but couldn't think of much to do with it. Maybe a min-Mars terrarium?",
"Short Answer: Yes, If they did it in a giant climate controlled, air tight green house.\n\nThe problem is Mars's does not have a dipole magnetic field like earth does. Our field does a bunch of things for us, mainly help protect our atmosphere from solar winds. So if in theory we were able to have a breathable atmosphere appear surrounding Mars, it would be blown away pretty quickly.",
"One oft mentioned means for colonizing Mars is pressurizing small enclosures to roughly 1/3rd ATM, and growing crops. Since Mars atmo is primarily CO2, you just pressurize the outside air. This generates cropstuff, and oxygen. Rinse, repeat.",
"I know that there is research being conducted on this very topic at my University and I was lucky enough to get a tour of the facilities. Quick link to the website of the Controlled Environment Systems Research Facility at the University of Guelph _URL_0_ and pdf of an article adresssing some of the issues _URL_1_",
"Even if it did work, the oxygen wouldn't last. The molecules travel too fast at average Martian temperatures to stay on the planet. Once a molecule gets to escape velocity and goes into space, it doesn't come back. We have this problem with helium on Earth. A lot of it escapes when we let it go and never comes back.",
"No. The tree would die. Low temps and pressure would kill it. It is as high as about mid 40's a foot or two off the ground but it gets colder as you get higher fast... in the 20's already by your head. It gets down to -90F at night. \n\nThe bigger issue that makes terraforming Mars difficult though, is there is little atmosphere, and it isnt coming back, and if we try to grow one, it will be blown away like the last one. Mars had a thicker atmosphere when it's core was still molten and could create a weak magnetic field to shield it from solar wind. The core cooled, the magnetic shield died, and the atmosphere blew away. Mars is smaller than Earth and further from the sun, possibly why the core cooled faster than ours.",
"In the open? Quite simply no. \n\nToo little atmospheric pressure, too cold, too dry, too much radiation. Remember: There are no trees in Antarctica and only very modest plant-life even though Antarctica is still comparatively hospitable. So you would need some sort of greenhouse, which would have to be a more or less completely closed and self-sufficient ecological system. \n\nSuch systems are [possible](_URL_1_), but very hard to maintain above a certain [stage](_URL_0_).\n\nBut assuming that you had all the technology and expertise needed, that you somehow found ways to produce all necessary resources in situ, that you managed to turn Martian regolith into viable soil (which actually is a massive problem), that you could keep the radiation out while providing enough light, then your tree would certainly grow and produce oxygen.\n\nAside from the lower gravity, I would exactly call its environment 'Mars' anymore, though. 'Earth in a jar' would probably be more fitting.",
"I know I am let to the party but I'd like to add my 2 cents.\n\nA tree is too big of a jump. There are a large number of extremophile organisms that already exists on our world. What we would need to find is an extremophile that can survive on mars or be bred to survive on Mars in the most habitable areas. \n\nDue to the large swings in temperature those organisms may have to live a few feet under the ground. Just as the earth has a stable temperture if you dig down, I am sure mars has the same, does anyone know what that temp is?\n\nApart from surviving the environment, the organism would need to do something productive to improve the environment for other organisms to survive. The first thing that would survive there would be an adjunct. An ideal candidate would be able to eat the iron oxide that is so abundant on Mars. A very hardy strain or symbiotic arrangement including Halomonas titanicae bacteria might work, im not sure if it only eats metal or if it eats rust as well. It's biological output would then be used to grow another organism, ie a water bear. You would build an ecosystem piece by piece in this manner until you could support larger life forms.\n\nWhats interesting about microorganisms is that some of them have aspects that are both plant and animal. Finding that first key organism may require evolving something in the laboratory or searching the world over but you only need one to start.\n\n\n*last thought* If you could somehow get water bears to carry out some photosynthesis you would have an incredibly hardy organism to test this out with.",
"I would be incredible difficult to grow a tree on the surface of Mars. As mentioned before, low atmospheric pressure would be a major concern. As would environmental factors like dust storms and low temperatures. In a greenhouse (likely a large reinforced plastic dome), it would be quite possible though.\n\nWhat would be a better idea would be the use of lichens. Lichens are a symbiotic relationship between certain types of fungi and cyanobacteria. Lichens tend to be among the first things to colonize a newly formed piece of rock because the fungi sequester water and certain nutrients and the cyanobacteria produce food via photosynthesis in exchange for water and nutrients. Lichens would probably make for an ideal colonizing species. ",
"You might want to start with lichen and algae that is adapted for the Martian environment. Laboratory tests prove that lichen can survive on mars. I think we should seed mars with early forms of life for future terraforming of the planet. We wouldn't need to ship water to the planet; if we melted the polar ice caps, it would cover most the surface with 36 feet of water. Why not start a flourishing eco-system on mars to convert it to a hospitable place for life?",
"The biggest problem with Mars is the low air pressure. Nothing that contains things that would be liquid on Earth (water being the biggest example) could live on Mars at the normal Martian surface pressure. Essentially, all the water in the tree would boil and evaporate. This evaporation, along with the cold of Mars, would freeze the tree solid.\n\nOne way around this is to make a dome and use Mars air to pressurize it and maybe heat it a little. The problem with a dome is if it fails, the tree would die, pretty quickly.\n\nA safer solution would be to make a **VERY** deep hole and use mirrors to shine sunlight down to the bottom and plant the tree there. Like the reverse of air at the top of a mountain, the air would get denser at the bottom of a hole and you could get the pressure up high enough to not immediately kill the tree. If the mirror broke, you would have several days to repair it before the tree died. You probably would still need a heater though.\n\nEDIT: I found an equation for the air pressure on mars for a given height above the surface. \n\n P=0.699*e^(0.00009*height)\nWhere P is in kPa and height is in meters. If we were shooting for about 25% of Earth's pressure, this equation says you would need a hole 40km deep. The equation isn't meant for negative altitude, so I suspect this number is WAY off.",
"The soil on mars is toxic to plant life as we know it on earth. There may be a select few plants here on earth that would be hardy enough to survive, however the list would be short. It's less about providing the plants with air to breathe on mars, so much as it is the toxic soil issue. \n\n",
"Wouldn't work, since Mars is close enough to the Sun Mars would receive the effects of a type of energy which the sun releases which would destroy Mars' atmosphere and in turn would have all of the water on Mars evaporated therefore not being able to sustain life due to a lack of atmosphere and water for the plants.\n\nBut wait there is more, you are probably wondering why Earths atmosphere isn't being destroyed by the Suns' release of energy the reason being so is because of the Earths magnetic field which is generated by the liquid iron outer core of the Earth convecting and rubbing against the inner core of the Earth, which is made of solid iron, creating a magnetic field which protects the Earth from the Suns release of energy. May not be completely accurate if you want to you can go on Netflix and watch the show called, How the Universe Works and watch the episode titled Planets or Formation of Planets I'm not to sure to get more accurate information.",
"This isn't directly related to the tree, but if we could raise the atmospheric pressure of Mars 600 Pa to well over 611 Pa (the triple point of water) liquid water could form during Martian summer. The problem right now is that even when Mars warms in summer, ice sublimes directly into water vapor because the pressure is too. If we some how raised doubled the pressure on the mars we could hypothetically get liquid water during the summer which would do a lot to aide a tree or better yet photosynthesizing cyanobacteria. ",
"Mars is outside of the green belt of Sol, so terraforming the planet in any useful way would be almost entirely out of the question. Now, closed systems where outside radiation is blocked and artificial sunlight, water, etc were contained, could work. But so do those bio-jars you can make that have a self-contained ecosystem, where the only outside influence is sunlight. By that argument, you could put one literally anywhere and it would be fine, if you gave it enough sunlight for photosynthesis.",
"without a magnetic field to protect the atmosphere of mars, like we have on earth the gasses will likely be blasted away anyway and not stick around too long. it will continually have an incredibly low pressure.",
"Biggest issues with Mars\n\n1. no magnetic field, unlike Earth and Venus who have molten cores, Mars has a solid core and thus no magnetic field to protect its atmosphere. Gases are constantly stripped away leaving a thin atmosphere, and harmful radiation can penetrate the atmosphere. Other than enclosures, we have no cure for this, so Mars may be a rock we can put a biodome on, but we'll never be able to enjoy a prolonged atmosphere\n\n2. Thin atmosphere, as stated above and elsewhere, air is thin, moisture gets sucked out\n\n3. Temperature, the thin atmosphere and lack of climate lead to desert like temperature swings. We can't simply warm the planet or add water, we need to build an atmosphere (see 2) and then protect it (see 1)\n\nSadly Venus is a much more suitable earth like planet, similar size, magnetic field, atmosphere sustainable. However, no moon (stabilize climate) and incredibly dense and poisonous atmosphere. I always wondered if we could swing a fairly round asteroid into an orbit around it and hit it with a comet or two (provide water, disrupt atmosphere and cool down the surface) if we couldn't come up with a planet that could be terraformed?",
"Short answer no. Long answer sure, but it would involve transporting most of the the Earth to mars. You would either have to transport Earth's molten core or build a giant radiation proof dome to protect the environment from radiation and atmosphere stripping effects. You would have to transport topsoil for whatever region you expect to populate. Grow lights to bring lighting levels up to earth standards etc. etc. For the most part recreating Earth on mars may be fun and interesting on a small scale for exploration, full scale terraforming doesn't make sense."
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2mk7fg | why did columbus think he had found india, and not china or japan? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2mk7fg/eli5why_did_columbus_think_he_had_found_india_and/ | {
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"He knew where he was at relative to the equator. Both India and the West Indies occupy territory around 21ºN. China and Japan are further north than that.",
"The indies were a general term for the East at the time. This is why we have a country named Indonesia (which was called the Dutch Indies), the East Indian Trading company, etc."
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w2ec2 | How is dark matter different than "the ether" | I understand the basics of what dark matter is, but I was wondering what evidence there is to truly prove it exists and what makes it different from the old theory of 'the ether' | askscience | http://www.reddit.com/r/askscience/comments/w2ec2/how_is_dark_matter_different_than_the_ether/ | {
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"This has been asked over and over again. Try searching. [This thread](_URL_0_) is particularly relevant.\n\nEssentially, both are theories formulated to explain phenomena. In the case of ether, the predictions of the theory did not explain later results, so the idea was dropped in good scientific fashion. In the case of dark matter, the predictions of the theory turn out to fit newer data extremely well, including where other theories such as modified gravity do not work well. So dark matter is a theory that fits with incoming evidence the best of all the alternatives, whereas the ether was a theory that did not do so.\n\nThere are lots of different phenomena that are extremely well explained by dark matter as a particle, but it is much harder to fit other theories to this data. For instance, modified gravity theories fit poorly with the [bullet cluster](_URL_1_), which instead shows dark matter distribution in excellent agreement with what a particle would do. Also, a dark matter particle is theoretically extremely plausible, it's not a strange idea in any way.",
"[Searched](_URL_1_)\n\nRelevant [discussion](_URL_0_)\n\nOriginal question by [Rautavaara](_URL_2_)\n\n > I've always had a side hobby in reading non-specialist texts on quantum physics (e.g. Hawking's \"A Brief History of Time\", Greene's \"The Elegant Universe\", Kaku's \"Hyperspace\", etc.). I recently watched a few episodes of Greene's \"Fabric of the Cosmos\" and honestly his explanation(s) of dark matter seem eerily similar to the basic idea(s) behind the Ether. Given I am a Ph.D. in a social science and not physics, I know that my knowledge is inadequate to the task at hand here: why is dark matter so plausible when the ether is laughably wrong?\n\nTop comment courtesy [iorgfeflkd](_URL_3_)\n\n > Ether isn't laughably wrong; it was a reasonable explanation until experiments (Michelson-Morley) and better theories (special relativity) made it unnecessary. Dark matter was hypothesized to explain the galactic rotation curve anomaly, which it does. It also fits with data that it was not contrived to fit, such as the mass distribution in the Bullet Cluster. It is also potentially possible to detect dark matter particles, either directly in experiments such as CoGeNT and DARMA (I think that's the acronym) or indirectly in the LHC.",
"If you explain why you think it's like ether maybe we can explain why it isn't.\n\nKeep in mind that ether wasn't a silly or invalid hypothesis, it was just wrong. Hindsight is 20/20."
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"http://www.reddit.com/r/askscience/comments/mn8ru/given_that_the_ether_was_so_discredited_what/",
"http://en.wikipedia.org/wiki/Bullet_cluster"
],
[
"http://www.reddit.com/r/askscience/comments/mn8ru/given_that_the_ether_was_so_discredited_what/",
"http://www.reddit.com/r/askscience/search?q=ether+dark+matter&restrict_sr=on",
"http://www.reddit.com/user/Rautavaara",
"http://www.reddit.com/user/iorgfeflkd"
],
[]
] |
|
6i0kd4 | why do some peoples have reddish, yellowish etc. tints to their skins? | I understand that peoples who moved to less sunny areas developed paler skin because they could not get the necessary vitamins from the sun. I am not wondering why some people are paler, but instead why some people are more reddish/ yellowish etc.
Edit: I mean more why are certain ethnicities and races tinted different colors, not related to heath issues. For example how most Asian people have a bronze hue to their skin whilst many Middle eastern peoples have a reddish hue to their skin.
| explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6i0kd4/eli5_why_do_some_peoples_have_reddish_yellowish/ | {
"a_id": [
"dj2jt5f",
"dj2kxfb"
],
"score": [
2,
3
],
"text": [
"I tend to get yellowish skin from time to time and it's due to Gilbert's syndrome, which is basically elevated level of bilirubin in bloodstream.",
"Yellow skin is caused by [Jaundice](_URL_0_) \n\nRed skin can be caused by a variety of reasons (sunburn, inflammation, blushing) all of which involve red blood cells congregating in your skin."
]
} | [] | [] | [
[],
[
"https://en.wikipedia.org/wiki/Jaundice"
]
] |
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