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3v6v7c | why do i sometimes get zapped when touching metals? how can i prevent this from happening? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3v6v7c/eli5_why_do_i_sometimes_get_zapped_when_touching/ | {
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"You are most likely building up a static charge by rubbing dry materials together. \n\nTurn on a humidifier and moisturize your skin.\n\n Pick up your feet when you walk, stop scuffing them, and stop wearing socks on carpet.\n\nPut anti static sheets in your dryer and and stop doing crazy dance moves in wool sweaters and nylon pants.\n\nWear leather soles shoes instead of rubber.\n\nThey also sell anti static spray you can put on carpets and chairs and whatnot too."
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46kt6w | In History, what was the extent to the Region known as India? How was this determined, if India was never unified until recently? | Historically, were places such as Kashmir, Tibet, Ceylon, Bhutan ever considered "India"? (Refering to the Region, not the Current Country). Were parts of Southeast Asia (Burma, Siam, Laos, Vietnam) considered parts of India when they were majority Hindu? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/46kt6w/in_history_what_was_the_extent_to_the_region/ | {
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"Wasn't the Mughal Empire in control of the majority of the sub continent for sometime?",
"As a geographic designation the \"Indies\" has referred to a very diverse region that covers South Asia and both mainland South East Asia and the islands as far east as the Philippines. You'll note that being included in this region doesn't have much to do with place's majority religion.\nOf the places you list in your first sentence only Tibet falls clearly outside of the Indies (all those big mountains keep it fairly separate), though Tibet has historically had interaction with the subcontinent, at one time Tibetans even conquered Bengal.\n\nIf you want to talk more narrowly about the country of India and its borders then that is defined largely by British colonial history and the obvious geographic limits imposed by the Himalayas and the ocean. The only part of mainland South East Asia ruled by the British was Burma and it was considered part of Indian territory until 1937. Both modern Pakistan and modern Bangladesh were also part of Colonial India. When the British granted Indian independence in 1948 they partitioned the country into majority Muslim (Pakistan) and majority non-Muslim (India) parts. Later the Bengal part of Pakistan bloodily broke away from West Pakistan. \n\nIts also not entirely true that it was never unified. The Maurya Empire from the (4th century BCE to 2nd century CE) for a time ruled over much of modern India, (excluding the very southern tip) Pakistan, Bengal and Afghanistan (as did the Mughals though not for as long and with much less imperial integration than the British who followed them). So it didn't 'unite' all of the modern territory of the Indian nation, but that's just privileging the present, one could equally argue that modern India fails to unify all of the territory of the Mauryan Empire (I'm sure some extreme Indian nationalist argue that their nation's borders should be much bigger on this basis)."
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y8ew9 | How does the developing fetus know the structure of the human body? In other words, how does the hand form during pregnancy instead of a glob of flesh? | I saw a creationist video talking about this saying the fetus must have a 'guiding hand'. Bullshit, I say. So I ask you reddit. | askscience | http://www.reddit.com/r/askscience/comments/y8ew9/how_does_the_developing_fetus_know_the_structure/ | {
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"The short answer is [hox genes](_URL_0_) and [programmed cell death](_URL_1_). Wikipedia gives a decent introduction. I'd be happy to elaborate if you'd like a bit less technical description.",
"This is kind of the root of embryology/development biology, which is a huge field with lots still to be discovered. At the adult level, differentiated cells have different levels of DNA expression - just because the DNA is there does not mean it is expressed the same way everywhere. There's a lot of regulation at both the chromosomal level (eg histone methylation, chromatin condensation) and the nucleotide level (eg transcription factors, mRNA splicing, etc). This is further mediated by signalling via chemicals (eg cytokines/growth factors/hormones etc), as well as physical parameters (eg the stiffness of the underlying substrate, or contact inhibition when cells become confluent).\n\nIn the fetus, one of the key players is the HOX gene, which regulates development along the anterior-posterior axis. Various defects in this signalling pathway may result in things like duplication of structures (eg with synpolydactyly). There are many others (if you're interested, check out Shh and wnt-7a), and while we have a general idea of what each one generally regulates, there are many details that are yet to be perfectly described.",
"It's getting on a bit now and may be out of date in some details, but there's a very accessible book on the subject called \"Triumph of the Embryo\", by Lewis Wolpert.",
"A great book about this is \"Your Inner Fish\" by Neil Shubin. He goes through all of this in great detail--all in a quite understandable way for the layman.",
"Determining the answer to this question is basically the goal of the field of [developmental biology](_URL_0_)."
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k9dhp | how a sonogram works and how they do a 3d image. | Soon to be dad and was wondering how all this stuff works.
Thanks in advance. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/k9dhp/eli5_how_a_sonogram_works_and_how_they_do_a_3d/ | {
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"A sonogram is basically a sonar (sound navigation).\n\nWhen you look at a person, you are observing light which has reflected from the them to your eye. A sonogram uses the same principle, it's just that we use sound waves which can travel past our skin and reflect off of our internal organs, or in this case, your child. Don't worry the waves are low energy and are not harmful. \n\nCongratulations on your child, I hope they are healthy and well. :) \n\nEDIT: I should clarify that there is a certain amount of risk taking a sonogram (ultrasound). The potential knowledge gained by the procedure however, far outweighs the risk.",
"A sonogram is basically a sonar (sound navigation).\n\nWhen you look at a person, you are observing light which has reflected from the them to your eye. A sonogram uses the same principle, it's just that we use sound waves which can travel past our skin and reflect off of our internal organs, or in this case, your child. Don't worry the waves are low energy and are not harmful. \n\nCongratulations on your child, I hope they are healthy and well. :) \n\nEDIT: I should clarify that there is a certain amount of risk taking a sonogram (ultrasound). The potential knowledge gained by the procedure however, far outweighs the risk."
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bh8b3f | why do currency exchange rates exist? why is it not just 1:1? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bh8b3f/eli5_why_do_currency_exchange_rates_exist_why_is/ | {
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"Because the value of things is different depending on the country you’re in. The GDP determines the value of money in a country. GDP stands for Gross Domestic Product, that is the total value of goods produced and services provided in a country during one year. \n\nSo lets assume England has a higher GDP than Iceland. Their dollar has a higher value than Iceland, because Iceland is not producing as much in terms of goods and services within their own boarders. So money needs to fluctuate to adjust for that."
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3igke8 | what is actually happening at evangelical church things when people speak in "tounges" and have fits and stuff? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3igke8/eli5_what_is_actually_happening_at_evangelical/ | {
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"nothing... its all a act, all these people that \"speak in tongues\" are just mouthing gibberish. they are actually getting themselves worked up emotionally but that is more a bi product of the crowd and the scenario. its the equivalent to a laugh track on a tv show. more people laugh if other people laughing. mix that in with religious guilt and bang, you have some poor bastard waiving his arms making goofy noises.",
"Hysteria would cover it. You see the same kind of thing in certain primitive tribes during their religious happening. \n\nOfc, you'll get the \"well they're wrong, but Jesus fills us\". Still, externally it's the same thing.",
"Depends on who you ask. If you ask them, [Glossolalia](_URL_0_) is channeling the God/Holy Spirit/ghosts and speaking an angelic language.\n\nTo anyone else, it's [self-hypnosis](_URL_2_), religious mania, and/or group therapy [psychodrama](_URL_1_)."
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4j80h8 | why are some youtube videos flagged for removal for minor use of music clips, but many other youtube videos of entire songs are left to be viewed millions of times no problem (and presumably monetized by someone without the rights)? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4j80h8/eli5_why_are_some_youtube_videos_flagged_for/ | {
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"YouTube doesn't flag them. It's the task of the copyright holder to find and flag any videos that may infringe.",
"YouTube has deals with some song rights owners, allowing videos to have the entire songs in, and any YouTube ad revenue from the video goes to the *song royalties*, and not to the video creator. I have a video on YouTube of my dog and cat playing like this: you can barely hear the song playing in a commercial on the TV in the background, but YouTube detected it and identified the rights owner, and all the ad money goes to some company in Germany. Otherwise YouTube would have not allowed the video on their site."
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2g16rz | why are ebooks generally just as expensive as their print counterparts when publishers don't have to account for ink, paper, and binding costs? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2g16rz/eli5_why_are_ebooks_generally_just_as_expensive/ | {
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"Price fixing\n\nSource: WSJ\n_URL_0_",
"The price of products is only indirectly based on how expensive they are to produce. The primary factor is how much can be charged for them.",
"You're paying for the intellectual property, not the physical artifact. Think of it this way, if the book was empty, just blank pages, it would cost a fraction of what the book with printed words actually costs. That difference is the value of the intellectual property. Take away the printing, and you can just make a lot more money. \n",
"You just described the question Amazon has been asking publishers, authors, and the general public. There is currently a war going on between ebook publishers and Amazon. Everybody knows that these books could easily be cheaper but publishers clearly do not want this.",
"Another post alluded to it, but a large part of it is that most of the cost to make a book is not in the per-unit costs; its in the writing, editing, and marketing of the book. Publishers need to pay writers (even writers who write books that don't sell!), they need to pay editors, they need to pay marketers, etc. And its not like distribution *goes away* magically when things are digital; stores like Amazon or Kobo still take a (substantial) cut, and people need to specifically format the e-book version to make sure it works on your Kobo, Nook, or what have you.\n\nOn top of this, there's very little reason for the publishers to undercut their own product by making the digital version of a release significantly cheaper; the publishers would largely be cannibalizing their own sales.",
"Everyone is offering different comments, but I question how many of you actually read ebooks?\n\nMy answer to OP is, ebooks are cheaper. I don't know where you are shopping, but ebooks are almost all cheaper, and discounted earlier in ebook form.\n\nI was going to provide links, but just go to _URL_0_ and look at books. Kindle versions are almost always the cheapest versions.",
"I'm an author for a major publisher. People have already said that the price is the same because it's simply how much they can charge. This is true, but I'd like to point out that they pass this on to the authors. They're not just greedy bastards! Typically an author's contract gives a much greater percentage of royalties for ebook sales than print sales. When you buy an ebook and feel like you're overpaying, please know that the artists that originally wrote those books and their families thank you. ",
"I might be able to shed some light. I actually run a small publishing business. It grew out of a hobby that I've had since I was young. I've been up and running for a few months as of right now. It isn't making me rich, but I am making beer money off of it right now. People have also already mentioned some of the reasons in this thread as well.\n\nOne reason for the cost of ebooks is that you have to pay programmers to actually make the ebooks. This is one extra cost that you have with ebooks that you don't have with paperbacks. Distribution platforms also take a substantial cut of sales as well. Technically I could lower prices for ebooks, but then it would take forever to make any money.\n\nAlso, things like printing/paper/binding/etc really aren't that expensive when you compare it to everything else that goes into making a book. When I sell a $16 book about $3 goes to printing and binding costs.\n\nWhat really costs money is things like getting the layouts done so that I can get it printed, artwork, and in my specific case translations. You're also going to have to pay editors, royaltees and then still make a profit. In my case, the actual printing costs are almost an afterthought.\n\nedit: I forgot to add that I make my ebooks cheaper than my paperbacks. Also from what I've seen, ebooks generally are less expensive that most physical copies.",
"I'm late to this party, but I'm going to say this anyway because there's a lot of nonsense here.\n\nEbooks from the big publishers are priced around $12-14 or more. Amazon are fighting all of them to get the price down to $9.99 at most. Self published authors have already figured out that the optimal price point is somewhere around $2.99-5.99.\n\nAmazon has the sales data to show that there's more profit to be made by dropping the price to increase the volume sold, and the big publishers are just not listening. They're pricing high because they want to stop ebooks from cannibalizing hardcover sales, even though the print market is dropping and has been doing so for a few years. They also hate Amazon and fear their market dominance, and they tend to overvalue their product.\n\nSo, fact is, ebooks are expensive because the big New York publishers make bad business decisions. They were convicted of collusion to keep the price of ebooks high by the DOJ, remember. They didn't do that because the market could bear a higher price; Amazon had it figured out that the higher price was suboptimal, hence the frequent discounts to $9.99.\n\nSo a lot of the reasons in this thread are missing the point. It's mainly about protectionism and flat out stupidity on the part of the big publishers. Self-published authors have almost all the same up-front costs (which are far less than you'd think, even with professional editing and design), and they price their books far more reasonably and make more money from them.\n\nThe whole industry has been getting a big shakeup in recent years, so don't be surprised if the price does come down significantly. Amazon are in a battle with Hachette right now over ebook pricing, and personally I think Hachette has zero chance of winning."
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3v2ebe | why do we prefer wider-screened tv's over just larger tv's? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3v2ebe/eli5_why_do_we_prefer_widerscreened_tvs_over_just/ | {
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"Because they better match our field of view. A wider screen means that more of our view is of the film/show. This makes it more \"immersive\", to employ some marketing-speak.\n\nAdditionally, for we old folks, the wide format was that of the movie experience and the narrow format was that of our lowly TVs. When we first got the wide-screen we couldn't help but feel we'd brought the theater home. ",
"Look in the mirror. You have two eyes, right? And those eyes are arranged one on the left and one on the right?\n\nTherefore, your total field of vision and more important your field of foveal vision, which you see things _well_ are wider than they are high.\n\nIf you had an Academy ratio (4:3) TV, a more substantial portion of where you see well would be \"wasted\" (on the real world)."
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6bvjua | why do so many acne medications require you to not be exposed to the sun? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6bvjua/eli5_why_do_so_many_acne_medications_require_you/ | {
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"A lot of acne medicines are tetracycline based antibiotics. These can sensitise your skin to sun light making it more susceptible to getting sun burnt. ",
"Acne mediation affect how the skin cell divided and proliferate. And consequently affect your skin barrier. Which make your skin more sensitive icity to the sun",
"Pharmacy student checking in here. Multiple acne medications can increase your sensitivity to sunlight. Isotretinoin and other retinoids, as well as the tetracycline antibiotics (and possibly others). One mechanism of action for certain kinds of photosensitivity is through the activation of the drug by sunlight, leading to a compound which produces some kind of irritation or prompts an immune response. These activated compounds may have reactive groups which damage DNA, or they may cause damage and inflammation through another mechanism. Lastly, as some of the other commenters have said, they may not have experienced a severe reaction to sunlight while on these medications. It is important to remember that not everyone will have these side effects. They may naturally have an excess of certain metabolic enzymes, more melanin production, an underactive immune system, or a whole host of other things which lessen or prevent this reaction. However, this can occur in most patients, and you should wear sunscreen when you plan on being outside for any length of time (skin cancer is bad!!)."
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6uli46 | Why was a garrison left on the Akropolis to withstand the Persian sack of Athens? | Seriously, I cannot get over it unless there is some religious reason, because elsewise, the garrison did not number greatly, and even if it was of great number to pour out if the Hellenic somehow magically ambushed them in order to hit the rearguard, well, the same thing it made the Akropolis good for defense makes it bad for sallies, that not many numbers are needed to hold the path, that would go both ways, so either way, the garrison was to be trapped, so once again, why was it left at all? Even if they were priests or whatever, I just... can't understand it. Please help me understand | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6uli46/why_was_a_garrison_left_on_the_akropolis_to/ | {
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"Herodotos is our only source for this story. He tells us that a few Athenians decided to stay behind on the Akropolis because of their alternative interpretation of the oracle that the Athenians had been given at Delphi in response to their urgent request for divine guidance. The god advised them as follows:\n\n Vainly does Pallas strive to appease great Zeus of Olympos;\n Words of entreaty are vain, and so too cunning counsels of wisdom.\n Nevertheless I will speak to you again of strength adamantine.\n All will be taken and lost that the sacred border of Kekrops\n Holds in keeping today, and the dales divine of Kithairon;\n Yet a wood-built wall will by Zeus all-seeing be granted\n To the Trito-born, a stronghold for you and your children.\n\n Await not the host of horse and foot coming from Asia,\n Nor be still, but turn your back and withdraw from the foe.\n Truly a day will come when you will meet him face to face.\n Divine Salamis, you will bring death to women's sons\n When the corn is scattered, or the harvest gathered in.\n\n-- Hdt. 7.141.3-4\n\nThe Athenians took the \"wooden wall\" in the oracle to be a reference to their fleet, citing the reference to Salamis as a prediction of where they would do battle. However, some argued instead that the \"wooden wall\" was the old thorn hedge that used to ring the Akropolis. They therefore assumed that the Akropolis would be the Athenians' stronghold, and that its wall would be impregnable.\n\nWhen the Persians actually invaded Attika, the Athenians mostly evacuated their people to Salamis and to Troizen across the Saronic Gulf. However, a few men stayed behind on the Akropolis. They blocked off the entry to the Akropolis with planks and doors, believing that they were creating the impenetrable wooden wall (Hdt. 8.51.2). The Persians soon proved them wrong, however, by setting fire to the barricade, climbing the Akropolis, and murdering everyone inside.\n\nIn short, there was certainly no military reason for the occupation of the Akropolis. If Herodotos is right, it was done *in defiance of* Athenian strategy, rather than as an element of it. The reason Herodotos offers is religious, but we might also speculate that the men who stayed behind were those who refused to abandon their homes to the Persians without a fight, or perhaps vainly hoped to compel the Athenians, Spartans and other Greeks to rescue them once the Persians laid siege to their position."
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35wbbj | why does obama and the republicans like the trans-pacific partnership and many democrats dislike it? are trade pacts good for american jobs? | What's the theories and how have they worked in the past? It seems to be a very complex subject. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/35wbbj/eli5_why_does_obama_and_the_republicans_like_the/ | {
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"It's incredibly complex, yes. The answer to your american jobs question is that it both helps AND harms the economy, it just depends what sector.\n\nIt would likely improve the job situation in any of the poorer countries, it would be very good for finance and financial services (LOTS of american jobs there), it would be good for retail, as goods can be imported cheaper.\n\nIt would likely be a bad thing for American Manufacturing in general. It would be a bad thing for anything that can be outsourced or offshored. \n\nThe main area of concern with most people is that we just don't know. Trade deals often deal with specific sectors in different ways, so we have no idea what effects it will have if we can't read it. "
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jh0a3 | warhammer 40k lore | I'm really digging the whole brutal empire of man, but I want to learn more. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/jh0a3/eli5_warhammer_40k_lore/ | {
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"The universe was broken by the eldar, they accidentally unleashed chaos into the universe, this chaos seeks to corrupt everything, the only thing standing in its way is the empire of man, lead by the god emperor in his golden throne, the eldar try to help but mankind wont have any of it and pretty much kill anyone who isn't human. Theres various alien species that exist in the universe, and mankind will kill any of them on sight. Also nuns with flamethrowers. ",
"There is an ungodly amount of information out there, so much that it is nigh impossible to give a brief synopsis. But:\n\n**15th millennium**: Dark Age of Technology - Actually a Golden Age that saw humanity hit its zenith in technology. The creation of the Iron Men (think Terminator-like robots) that worked and fought for humans was, at first, a great and wonderful thing. But...\n\n**25th millennium**: Age of Strife - The Iron Men revolt, technology breaks down and the vast empires of Man are sundered when the Warp becomes much more prevelant. The rise of Chaos and uncontrolled psykers caused much trouble for man, lasting centuries.\n\n**30th millennium**: First Founding - The Space Marines are created.\n\n**31st millennium**: Horus Heresy - The God Emperor is almost killed by his most trusted friend. Chaos marines are born. Fifteen novels are written detailing this time frame. Black Library rejoices.\n\n**31st millennium**: The Age of Man (Age of Imperium) begins\n\nLots of other stuff.\n\n",
"[The TVTropes page for it](_URL_0_) is surprisingly informative.\n\nAnyway, since you seem to understand the Imperium, I'll explain some of the other factions:\n\nThe Tau Empire is the closest thing you get to \"good guys\" in Warhammer. The main reason they're nicer than other factions is they'll at least offer you a chance to join before they start blasting you to pieces. Their society is broken into 5 castes: Fire (warriors), Air (pilots), Earth (builders), Water (uh, I forget) and Ethereal (leaders). Ethereals are very rare, but very powerful. They also exude some sort of pheromone that makes it impossible for other Tau to disobey their orders. \n\nUnlike the Imperium, the Tau embrace progress and have advanced technologically at an impressive rate, going from cave dwellers when they were discovered 6000 years ago to flying around in hover tanks with plasma guns by \"current\" times. Their empire also includes various other races like the Kroot, a savage race that gains strength by eating the bodies of foes (which tends to be a problem when the Tau fight Chaos), the insectlike Vespids and even some humans.\n\nThe Eldar are space elves. Very old, very technologically advanced, but on the verge of extinction. They come in three flavors: Dark Eldar are exactly what they sound like. They thrive on torture and feed on the souls of their enemies. Craftworld Eldar are probably what most people mean when they talk about Eldar. Each Craftworld generally focuses on one specific thing. For example Biel-Tan is a warrior Craftworld, Ulthwe is the Craftworld of seers, or something. Exodite Eldar are pretty rare and not a playable race in the game. They're like space wood elves, sort of. They eschew technology and just sort of live all primitive like on \"Maiden Worlds.\"\n\nAll Eldar used to be a bit like the Dark Eldar, actually. Not as much with the torture and murder, but they embraced debauchery and generally having a good time. However their society got so wild and debased that they actually spawned a Chaos god (Slaanesh) who is now out to consume the souls of all the Eldar. The Dark Eldar keep their own souls safe by feeding on the souls of others, while Craftworld Eldar protect themselves by storing the souls of their dead in soulstones.\n\nThe Necrons were once the Necrontyr, a very short lived race that I guess were jealous of races that lived longer, and eventually came to hate everyone else. The C'Tan Star Gods (that's not just a cool name, their gods are actually stars sort of) replaced their bodies with a living metal, making them immortal and essentially unkillable. (They can be defeated in combat, but can always be repaired.) Most of them lie dormant in underground tombs with pseudo-Egyptian themes, but once they're awakened they do not rest until they've exterminated all life on a planet.\n\nThe Tyranids are ravenous aliens from outside the galaxy. You are no doubt familiar with Starcraft's Zerg, yes? Well they're based on the Tyranids. Tyranids have a massive hive mind and just go around devouring everything on a planet to add to their stores of biomass. \n\nOrks are the comic relief. Seriously. Their actual history is that they were genetically engineered by some ancient race as warriors/guardians/whatever. A plague destroyed their creators and the Orks were left to roam the galaxy, looking for fights because that's what they do for fun. Ork infestations are almost impossible to get rid of as they release spores when excited (and considering how much they like fighting, they're excited pretty much any time they're awake) which can grow into a new Ork in something like 6 months I think. Orks are also strangely psychic, and most of their technology works because they believe it does. \n\nChaos: Demons and traitors and all that lot. The Imperium but with more spikes and carnage and giant medieval demons with horns.",
"The universe was broken by the eldar, they accidentally unleashed chaos into the universe, this chaos seeks to corrupt everything, the only thing standing in its way is the empire of man, lead by the god emperor in his golden throne, the eldar try to help but mankind wont have any of it and pretty much kill anyone who isn't human. Theres various alien species that exist in the universe, and mankind will kill any of them on sight. Also nuns with flamethrowers. ",
"There is an ungodly amount of information out there, so much that it is nigh impossible to give a brief synopsis. But:\n\n**15th millennium**: Dark Age of Technology - Actually a Golden Age that saw humanity hit its zenith in technology. The creation of the Iron Men (think Terminator-like robots) that worked and fought for humans was, at first, a great and wonderful thing. But...\n\n**25th millennium**: Age of Strife - The Iron Men revolt, technology breaks down and the vast empires of Man are sundered when the Warp becomes much more prevelant. The rise of Chaos and uncontrolled psykers caused much trouble for man, lasting centuries.\n\n**30th millennium**: First Founding - The Space Marines are created.\n\n**31st millennium**: Horus Heresy - The God Emperor is almost killed by his most trusted friend. Chaos marines are born. Fifteen novels are written detailing this time frame. Black Library rejoices.\n\n**31st millennium**: The Age of Man (Age of Imperium) begins\n\nLots of other stuff.\n\n",
"[The TVTropes page for it](_URL_0_) is surprisingly informative.\n\nAnyway, since you seem to understand the Imperium, I'll explain some of the other factions:\n\nThe Tau Empire is the closest thing you get to \"good guys\" in Warhammer. The main reason they're nicer than other factions is they'll at least offer you a chance to join before they start blasting you to pieces. Their society is broken into 5 castes: Fire (warriors), Air (pilots), Earth (builders), Water (uh, I forget) and Ethereal (leaders). Ethereals are very rare, but very powerful. They also exude some sort of pheromone that makes it impossible for other Tau to disobey their orders. \n\nUnlike the Imperium, the Tau embrace progress and have advanced technologically at an impressive rate, going from cave dwellers when they were discovered 6000 years ago to flying around in hover tanks with plasma guns by \"current\" times. Their empire also includes various other races like the Kroot, a savage race that gains strength by eating the bodies of foes (which tends to be a problem when the Tau fight Chaos), the insectlike Vespids and even some humans.\n\nThe Eldar are space elves. Very old, very technologically advanced, but on the verge of extinction. They come in three flavors: Dark Eldar are exactly what they sound like. They thrive on torture and feed on the souls of their enemies. Craftworld Eldar are probably what most people mean when they talk about Eldar. Each Craftworld generally focuses on one specific thing. For example Biel-Tan is a warrior Craftworld, Ulthwe is the Craftworld of seers, or something. Exodite Eldar are pretty rare and not a playable race in the game. They're like space wood elves, sort of. They eschew technology and just sort of live all primitive like on \"Maiden Worlds.\"\n\nAll Eldar used to be a bit like the Dark Eldar, actually. Not as much with the torture and murder, but they embraced debauchery and generally having a good time. However their society got so wild and debased that they actually spawned a Chaos god (Slaanesh) who is now out to consume the souls of all the Eldar. The Dark Eldar keep their own souls safe by feeding on the souls of others, while Craftworld Eldar protect themselves by storing the souls of their dead in soulstones.\n\nThe Necrons were once the Necrontyr, a very short lived race that I guess were jealous of races that lived longer, and eventually came to hate everyone else. The C'Tan Star Gods (that's not just a cool name, their gods are actually stars sort of) replaced their bodies with a living metal, making them immortal and essentially unkillable. (They can be defeated in combat, but can always be repaired.) Most of them lie dormant in underground tombs with pseudo-Egyptian themes, but once they're awakened they do not rest until they've exterminated all life on a planet.\n\nThe Tyranids are ravenous aliens from outside the galaxy. You are no doubt familiar with Starcraft's Zerg, yes? Well they're based on the Tyranids. Tyranids have a massive hive mind and just go around devouring everything on a planet to add to their stores of biomass. \n\nOrks are the comic relief. Seriously. Their actual history is that they were genetically engineered by some ancient race as warriors/guardians/whatever. A plague destroyed their creators and the Orks were left to roam the galaxy, looking for fights because that's what they do for fun. Ork infestations are almost impossible to get rid of as they release spores when excited (and considering how much they like fighting, they're excited pretty much any time they're awake) which can grow into a new Ork in something like 6 months I think. Orks are also strangely psychic, and most of their technology works because they believe it does. \n\nChaos: Demons and traitors and all that lot. The Imperium but with more spikes and carnage and giant medieval demons with horns."
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ezdppw | what is the best thing the average person in a more-developed country can do to improve the life of the average person in a less-developed country? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ezdppw/eli5_what_is_the_best_thing_the_average_person_in/ | {
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"One average 3^rd world person = marry them.\n\nAll average 3^rd world people = raise your children to study engineering and appreciate the necessity of contributing to those less fortunate than themselves."
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9ivgnc | if we have the ability to create tall skyscrapers, why don’t cities have a bunch of skyscrapers of the same height? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9ivgnc/eli5_if_we_have_the_ability_to_create_tall/ | {
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"Each builder is going to do what they want.\n\nGoogle pictures of Beijing some time, they have entire large blocks of buildings the same style and height. They also are far more regulated about how they build.\n\nI imagine in a more free market economy, each builder wants their building to be \"their building\" and not like another one. Plus each builder has a plan, purpose and marketing approach to create a profitable building, and that's going to differ from developer/investor to developer/investor.\n\nYou'd have to ask an engineer, but another short answer is the materials and design of the building will also dictate what is optimal. So again, with each design being different, making the building as tall as another building is just not going to even make the bottom of the priorities list for the engineer/builder/investor/developer teams.",
"It has less to do with engineering and more to do with politics.\n\nIf someone proposes building a high-rise, there's liable to be all kinds of complaints from people who live nearby. High rises block peoples' views, they put pressure on infrastructure, they bring lots of people into the neighbourhood, etc. \n\nSo city planners have to balance the willingness to densify their city with concerns that the residents might have. ",
"Well.... because, each company wants their own building. think of it like buildings owned by different people, all who want their own looks, heights, needs. ",
"It is much cheaper to build out than up. Two 50 story buildings are much cheaper than one 100 story building, and ten 10 story buildings are cheaper still.\n\nThe height of a building is going to be a function of the prevailing economic conditions. Is the extra cost of having one building in Manhattan justified over having two in Queens or ten in New Jersey?\n\nIn addition, building that 100 story building will put a glut of real estate on the market, making the next 100 story building less valuable.",
"And, in addition to the other posters, building height of a skyscraper is a safety question. Basically, the more relaxed your safety standards are, the higher you can build. Different cities over the world have different safety standards, and therefor different maximum heights.\n\nThis is not to imply that higher buildings are unsafe, but it gets more expensive to make them safe, adding the the great number of economic limiting factors."
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6hrcke | When someone wakes up from a coma lasting an extended period of time (months-years), what happens to their short term memory? | If they are in a coma for a long time, do they remember things that happened the day/night before they entered the coma as if they just happened? For example, will a patient who's been in a coma for a month remember exactly what meal they had before entering the coma? Or will they be groggy about things and remember only general things like going into work or getting into an accident?
Follow up question, is it different for each person? And if so, are there any trends seen with the type/length of the coma and the memory issues? | askscience | https://www.reddit.com/r/askscience/comments/6hrcke/when_someone_wakes_up_from_a_coma_lasting_an/ | {
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"Very dependent on circumstances.\n\nThere is a general idea in the public's mind about comas which is more informed by representations in movies, books, and TV than it is by fact.\n\nA coma is an abnormal state of unresponsive unconsciousness. Not only is the person not aware, they respond minimally or not at all even to painful stimuli.\n\nComas occur with serious brain injuries or intoxications. As a result, much more depends on the long-term outcome of the injury than it does on the coma itself.\n\nSo consider patient A who is comatose due to severe septic shock and compare to patient B who is comatose due to multiple traumatic intracerebral hemorrhages.\n\nPatient A, if they recover from sepsis, may have few ongoing problems afterward. Patient B may have significant and permanent issues with memory and cognition after recovery."
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9jez9f | WWII: During the Attack on Mers-el-Kébir the British attacked French ships, what was the sentiment after the war? | Over 1200 French sailors were killed by the British. Did the British ever apologize? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/9jez9f/wwii_during_the_attack_on_merselkébir_the_british/ | {
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"No. They didn't. Operation Catapult did sour Franco-British relations during the war itself, making, for example, recruitment into the Free French more difficult. And, of course, after many remaining French capital ships were scuttled at Toulon to prevent falling into German hands, the French believed they had demonstrated both their honor & the needlessness of the Mers-el-Kebir attack. Certainly this sentiment carried over into the post-war world, especially among the armed forces. But when you consider that the French had agreed to neutralize their ships prior to the Armistice, then later agreed to bring them back into French ports under occupation, it was difficult to hold Churchill in the wrong.\n\nAdmiral Somerville, who carried out the attack, believed it would permanently harm British credibility as an ally, but of course it did the opposite. FDR could assure Congress that the fifty destroyers the British coveted wouldn't likely fall into German hands. It made the entire Lend-Lease program work that much better.\n\nOf course, that's not what you asked. I know that in spite of anti-British sentiment, exacerbated by Goebbels during the occupation, very little of it carried over past the war into practical relations. DeGaulle had been supported as the leader of first the Free French, then France herself. His focus was on restoring the country & her colonial empire, & so couldn't afford to maintain grudges. \n\nMy own opinion, take it what you will, is that ordering Catapult was likely the single most momentous & consequential decision of World War Two, because not only did it demonstrate Britain's resolve & open Lend-Lease, it also may have inspired FDR to initiate an undeclared naval war against the Kriegsmarine that prompted Hitler to declare war after Pearl Harbor & resolve any remaining vestiges of America First! isolationism.\n\nI believe it would very difficult, even in light of the Toulon scuttlings, for French leaders & historians to find fault with Mers-el-Kebir given those circumstances."
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20uu8w | Would a deflated party balloon that is tied off seem to "inflate" when put in outer space? | The balloon would have some air inside. Not vacuumed out. Just curious as to what would happen. | askscience | http://www.reddit.com/r/askscience/comments/20uu8w/would_a_deflated_party_balloon_that_is_tied_off/ | {
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"Yes. You can do this on Earth in a vacuum chamber."
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110k7r | Why is entropy "the energy unavailable to do work"? What does that mean?? | I'm learning about the second law of thermodynamics, something that I've learned about before.
But now that I've stepped back to think about it, I have NO IDEA what my textbook means when it says that entropy is the energy unavailable to do work.
How does dS=Q/T translate to energy unavailable to do work?
Thanks in advance! | askscience | http://www.reddit.com/r/askscience/comments/110k7r/why_is_entropy_the_energy_unavailable_to_do_work/ | {
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"One of the problems with thermodynamics being taught separately from statistical mechanics is that it provides no basis for understanding entropy. Anyway, one way to think about entropy (via Feynman) is to think about trying to dry off after taking a shower. You want a towel that's much drier than you are, because a wet towel will just get you wetter. You won't get a perfectly dry towel because there's always some ambient moisture in the air. So you can try yourself with a towel that's pretty dry. Now think about having to dry lots and lots of things with the one towel. Eventually the towel will get so wet that it will stop picking up extra water from other stuff, but its not sopping wet. It's still has some amount of \"dryness\", but you can't use it for drying things. In this case, think of \"dryness\" as energy. A damp towel has more entropy than a dry towel.",
"Depending on how you want to look at it, entropy is:\n\n* Energy unavailable to do work (or a measure of it) - the classical thermodynamical view.\n\n* The 'disorder' of the system - the way it's often described/taught, although it has its drawbacks.\n\n* A measure of the distribution of energy in a system - my personal favorite.\n\n* A measure of the amount of 'information' in the system, in a rather abstract sense. (this isn't really necessary to understand physical entropy though)\n\nIt sounds a bit like Zen philosophy, but once you figure out how all these different views can be describing the same thing, that's when you've reached enlightenment on what entropy really is. (and it can take a while to wrap your head around it)\n\nTake an ideal gas in a box. This only has one energetic degree of freedom (form of energy) in it: The kinetic energy of the gas particles. Distribute some energy among the gas particles however you like - make them all move at the same speed, or put all the energy into one particle while the others are stationary. However you want. Then let the particles bounce around randomly for a while and equilibrate. At equilibrium, the velocities become [Maxwell-Boltzmann](_URL_0_) distributed, and stay that way. This is a purely statistical thing - you might start with all the energy in a single particle, but it's incredibly unlikely that all the energy will re-concentrate back into one. Just as you don't notice all the particles suddenly concentrating into one corner of the box, etc.\n\nThat's entropy. Having the M-B distribution among the particles is the most probable state (after a long period of time). It's the state with the highest entropy. In a statistical-thermodynamical view, the Second Law is really just saying that the system, over time, will end up where it's statistically most likely to be. You can also see the link to 'disorder' here, as having all the energy in one particle, or having the energy distributed exactly equally among the particles, are more 'ordered' states.\n\nWhat does this have to do with the ability to do work? Well, 'work' (such as mechanical work, but it doesn't have to be that) is a _single_ energetic degree of freedom. Being able to do more work, means having more energy in that degree of freedom - the others don't matter. For instance, a falling object can perform more work the farther it has to fall - but you won't get any more work out of its falling just because it's hotter or colder. \n\nWhen an object falls and comes to a stop, it has lost its kinetic energy to 'heat' and gained temperature. Meaning its kinetic energy has become distributed 'evenly' (in a Boltzmann sense) among all the other degrees of freedom of the system (most significantly the translational/vibrational/rotational kinetic energy at the molecular level). Since it's evenly distributed, it'll stay that way and can't do any work. No more than the evenly distributed gas will spontaneously put itself into a corner.\n\nYou cannot extract any work from the thermal energy of an object, or the pressure of a gas (etc) alone. The only way to do so, is if you have a _difference_ in temperature/pressure/etc that you can exploit, a system which is _not_ in equilibrium, where the energy is not evenly distributed yet.\n\nYou can transfer energy without losing much (or any) of it, if the energy is in a form that doesn't easily get transferred to the other forms around. (For instance, in an electrical superconductor) But when you're transferring _heat_, this is not possible - because thermal energy is by definition energy that belongs to _all_ the degrees of freedom (and thus can't be isolated from them). \n\nSo when you transfer heat from a hot object to a cold one, entropy will always be created (by _at least_ the amount dS = dQ/T), because your new system is larger, and in a larger system you can distribute the energy in more ways. (If you return to the ideal-gas-in-a-box, simply increasing the size of the box will increase the entropy)\n\nThere's simply a limit to how much of the flow of thermal energy you can 'divert' into a single form of energy. Some of the energy is just going to get spread around evenly, creating entropy. Thus entropy can be viewed as the energy involved in this process that is unavailable to do work.\n\n"
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6jwnoc | stupidly, i replied to a text near a petrol bowser & was embarrassingly told off over the pa system to "get off your phone", in front of everybody. what're the actual concerns for using phones at service stations? (and how stupid was i?) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6jwnoc/eli5_stupidly_i_replied_to_a_text_near_a_petrol/ | {
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"It's an urban myth that mobile phones can ignite gasoline vapor (it's actually static electricity, which doesn't come from a phone).\n\nIt's complete bunk, and they're parroting misinformation. Just keep a good ole \"fuck you\" chambered when they say nonsense like that.",
"As far as using a cell phone at a gas station and having it start a fire, that's been well proven as a myth. \n\nThe biggest problem with someone using a cell phone at a gas station is operator inattention. Walking into traffic, forgetting to remove the gas nozzle from the car before driving off, not paying attention to any possible equipment malfunction such as the gas nozzle auto-shutoff not working.",
"Don't feel too stupid. As a former gas jockey I can tell you that there are still people who have to be reminded not to smoke while filling up. ",
"Trivia but a little on topic - real risk is using a purse. Women much more likely to have fires at the gas station as they get in and out of their car to fiddle with their purse and static electricity builds up to cause a spark. Happened several times.\n"
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bskx63 | What was the highest percentage of 'men living in monasteries' that was ever reached? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/bskx63/what_was_the_highest_percentage_of_men_living_in/ | {
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"As a follow-up question: how does the percentage of people who have either taken vows and living in monasteries/convents along with lay people living there change when talking about Medieval Europe in comparison with other countries with strong monastic traditions such as the Theravada Buddhist kingdoms of Southeast Asia or the Tibetan Buddhist cultures of the Himalayas?",
"When asked about what the time was where religious fervour and zeal reached its peak, most people would probably say \"the Middle Ages\". But, well - it's not *quite* right. It's hard to quantify religiosity, of course, but at least for the Catholic Church the heyday more likely has to be located in the Baroque, i.e. that era between the late 16th and the late 18th century (depending on where exactly you're looking) where the cultural and especially religious spheres were totally dominant in everyday life, made all the clearer by having a direct comparison to Protestant Europe where this was very much not the case.\n\nWhat the Baroque also has going for it is that historians can generally work with much more sources than the Middle Ages. While we therefore also can't rule out that medieval Europe was teeming with monastic clergy much more than we thought before, we can at least say that there were a *lot* of monks and nuns in the Catholic Baroque, and at least to my knowledge there is no reason to assume that their relative numbers didn't eclipse all other periods in history.\n\nSo, how many men were living in monasteries during that time? Well, first there are the limits of what we can say: While the sources tend to be much better for the Early Modern Era than for earlier times, they are still far from being truly comprehensive, especially when it comes to demographics and reliable statistics. That said, some scholars have tried to gather as many data about early modern clerical demographics as possible.\n\nAs mentioned above, the Baroque's exact timeframe varies between countries and regions. Nevertheless it seems to be a safe bet that for all of Europe altogether, the peak of monastic religiosity was reached in the mid-1700s. Taking a look at the disparate statistics, we know for example that in 1792 about 0.26% of all Bavarians were men living in monasteries, but that was at a time when the Baroque boom had been long past. The Habsburgs census of 1781/87 came up with some 24,000 monastic clergy altogether in the dynasty's various territories, most of which were men. In France there might have been more than 3,000 male monasteries with an unknown number of total inhabitants. In 1765, the Portuguese authorities counted 531 monasteries with roughly 42,000 monks and nuns in between them at a ratio ofabout 3:1. For 1650 the *inchiesta innocenziana*, a monastic census ordered by Pope Innocence, came up with exactly 6,238 male convents in all of Italy with \\~70,000 men living in them equalling 0.61% of the population, although later research shows that even this ambitious census wasn't fully comprehensive either. The Capuchins, one order out of many (though a pretty popular one, to be fair), rose to 33,000 members in 1754.\n\nSo, how many altogether? It's of course hard to say, but Peter Hersche estimates that at its peak up to half a million men and women might have lived in monasteries in Europe alone, with men making up at least half of that. For all of Christian Europe, Protestants and Orthodox included, this would come out as a a percentage of maybe 0.25% of men living in monasteries and quite possibly even more (depending on your exact definition of \"Europe\", of course).\n\nApplied to all of Europe, this number isn't all that helpful however, at least if you ask me. The differences between the regions were vast; while in Protestant areas the number of monks was obviously zero, their percentage could easily rise up to 5% of the population in some mediterranean cities like Lecce and Valladolid.\n\n**Sources:**\n\n* Derek Beales: Prosperity and Plunder. European Catholic Monasteries in the Age of Revolution, 1650-1815, Cambridge 2003.\n* Peter Hersche: Muße und Verschwendung. Europäische Gesellschaft und Kultur im Barockzeitalter, Freiburg/Basel/Vienna 2006."
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408z5a | How much did the invention of the nuclear bomb affect Carbon 14 dating? | askscience | https://www.reddit.com/r/askscience/comments/408z5a/how_much_did_the_invention_of_the_nuclear_bomb/ | {
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"Oooooh. So much. Eventually anyway. (Also, be sure to see the below comments, people have some interesting corrections/nuance below).\n\nThe bomb spike began along with large-scale atmospheric nuclear testing. In earnest, this means it peaks ~mid 1960s, (below I've not NOAA's link.) \n\nIn short, as one might expect every bomb represented a huge flux of C14 into the atmosphere. C14 has a natural generation rate; its the result of cosmic ray bombardment of the upper atmosphere. Sometimes after the cosmic ray hits the atmosphere, yadda yadda yadda (i.e. various reactions), a free neutron is born. When this neutron hits an N14 atom, it may knock off a proton, creating C14. IF the neutron hits a C12, you have a C13 waiting and ready.\n\nAtomic bursts represent huge spikes of neutron radiation. (An aside. Uranium-235 may spontaneously decay by neutron decay, and if this neutron hits another U-235 atom, it too will break apart. Usually it releases 2 neutrons. Get enough of these close together, you achieve criticality and boom!. Additionally, many daughter particles of nuclear detonations release neutrons as well. While fusion detonations don't themselves release neutrons, the Teller-Ulam design (believed to be the US thermonuclear design as well as the Soviet/Russian) relies on an atomic devices as the detonator. Yes I just used nested parenthesis, deal.) \n\nWhen all these neutrons went out into the atmosphere they created a large amount of C14. Since this occurred in the upper atmosphere, the global wind patterns help achieve rather quick and equal distribution. The result is a huge influx of C14 into the terrestrial biosphere, well above the natural range. As with natural C14, plants take up C14 as part of heavy-CO2 in the course of their normal photosynthesis.\n\nThe result is it is really easy to date something as coming before or after the ~60s, based on the amount of C14. Anything which died before the \"bomb spike\" as it's called has a much lower percentage of anything coming after. \n\nThe bomb spike is really useful, especially in my field (ag-science), in archaeology, geology etc. This is especially true given the amount of land disturbance which has occurred in the last 50 years. Places without bomb-spike material have obviously not been heavily modified since the 60s.\n\nThe bomb spike is ending. For the most part, the additional heavy CO2 has partitioned into the oceans. We're also diluting it by increasing the CO2 levels with all our fossil fuels (the C14 has a half life ~5000 years. After a few million there's nothing left).\n\nTL, DR: The proliferation of large-scale atmospheric nuclear testing created a huge spike of C14 in the atmosphere. It is really easy to tell if something lived before or after the 1960s. \n\nNOAAs stuff: _URL_0_\n\nEdited for accuracy.",
"Nuclear weapons and testing also affected the amount of tritium in surface waters. You can tell the difference between water from before the 50/60s and after. The before water might be old groundwater, frozen ice or water isolated from the general water cycle in some other way. You can use this to age date water over the past 100 years. Here's a review on the topic:\n\n_URL_0_",
"I read somewhere that the scuttled fleet from Germany in WW1 was sometimes mined as a source of pre-atomic age steel for some purposes because of this\n\nIs that right? And if so, what uses would it be good for?",
"Other posts (like Osageandrot) accurately answer your question.\n\nI can add that, on the contrary, burning fossil fuel releases a lot of old carbon in its CO2,thus lowers the C14 part in the atmosphere. This effect is for example noticeable near big roads: the C14 map isn't homogeneous.",
"There is a term from archaeology, Before Present, where the time 'present' is fixed to mean 1 January 1950 because radiocarbon dating after that time will be unreliable due to the changed proportions of carbon isotopes in the atmosphere due to nuclear testing.",
"Something to add: the use of nuclear bombs (testing) in the 60s also added a unique opportunity to neuroscientists, oddly enough! The increased carbon 14 at the time was incorporated into brain cells. This allowed scientists to use the levels of C14 to determine how much adult brain cells were still regenerating. It was a clever way to take advantage of the C14 spike during nuclear bomb testing. \n\nHere's a news article of that paper: \n\n_URL_0_"
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bs10ss | How does Trans-cranial magnetic stimulation(TMS) work? | I read about TMS in a neuroanatomy book and am under the impression that it basically works by the principle of electromagnetic induction and this is exactly what I cannot seem to understand. For an electric potential to be induced there are two requirements- 1) Changing magnetic fields and 2) There should be a conductor present in these changing magnetic fields for electrical potential to be induced. How is the brain tissue a conductor? I mean of course brain is electrically active but that is due to the exchange of ions as far as I know and neurons mostly work in two mode inhibitory and excitatory states, how does TMS affect this in any significant way and bring about the effects mentioned in the book? | askscience | https://www.reddit.com/r/askscience/comments/bs10ss/how_does_transcranial_magnetic_stimulationtms_work/ | {
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"How this works, I’m not exactly sure, but physics states that the ions in question would be physically affected by the field, so it’s possible that the electromagnetic field affects the quantum vibrations of the ions. This could have a very real effect; the new field of quantum biology attributes olfactory perception to the detection of quantum vibrations of molecules trapped in smell receptors. This indicates that it wouldn’t be a huge leap to consider that neurotransmitters work in the same way...\n\nThat may not answer your question but it was definitely fun to think about!",
"The electric fields induced by TMS drive currents within the neurons themselves. A *current* is any movement of charge; in metals we think of currents as electron flows but currents can be carried by ions as well. Currents in the neurons can drive membrane voltages above the depolarization threshold and cause action potentials to fire. Or conversely, can drive the membrane voltage into the more hyperpolarized state, reducing the chance of action potential generation."
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svh7a | Would Mars be considered to be in "Habital Zone"? | askscience | http://www.reddit.com/r/askscience/comments/svh7a/would_mars_be_considered_to_be_in_habital_zone/ | {
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"Mars is considered to be just outside the habitable zone for our star\n\n_URL_0_\n\n_URL_1_\n\n_URL_2_"
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ttmjm | So what would happen if a thimble full of Neutron Star were to suddenly transport itself instantly into empty space? | Number 6 on this link: [10 Mind bending facts about the universe](_URL_0_)
In case you don't click the link:
6. Just a thimbleful of a neutron star would weigh over 100 million tons.
So what would happen if this little thimbleful of star were to pop in empty space?
Would it explode? Expand? Or would it be like "naa, i'm just gonna stay a thimble size, try and pick me up foo!" I'm curiously confused... | askscience | http://www.reddit.com/r/askscience/comments/ttmjm/so_what_would_happen_if_a_thimble_full_of_neutron/ | {
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"It would expand phenomenally fast (might as well define it as an explosion), as the force compressing it would be gone. It would be at a very high temperature, but more than that the structure of a neutron star is extremely unstable and only held in place by the massive gravitational field of the star, so most of the force of the expansion would, I would say, come from the nucleons returning to lower energy states.\n\nBasically though, big big explosion."
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18jrf5 | If I had cuts on eat hand... Bandaged then together for a few weeks would skin/nerves/blood vessels for and heal together? | askscience | http://www.reddit.com/r/askscience/comments/18jrf5/if_i_had_cuts_on_eat_hand_bandaged_then_together/ | {
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"Each them. \n \n \nSorry typing on my phone",
"If you ensured they don't move...yes.\nSome time ago a firefighter suffered bad burns to his hand They sliced him open and shoved the hand inside his abdominal wall. Once enough tissue regenerated they could apply skin grafts.\nThe idea of two hands fusing would be similar, provided the cuts were deep enough.\n_URL_0_"
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2m8im0 | Why do the majority of Native Americans in the US have significant European heritage, if English settlers rarely intermarried with native people? | Was this because of institutionalized rape by white men? Or adoption of white children by Native groups?
Was there ever an initiative to "whiten" Native Americans ethnically? Not through cultural change, but through forced marriage. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2m8im0/why_do_the_majority_of_native_americans_in_the_us/ | {
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"Native Americans are the most exogamous ethnic group in the US. Being only 2% of the population has a lot to do with that, as well as strict tribal taboos against marrying any relative, not matter how distant. Many tribes also have rules against marrying within your clan or moiety.\n\nA great deal of intermarriage between Native and European-Americans has happened in the last century. During the 20th century, many Native Americans left their tribal homelands for jobs, as part of military service, or as part of the [1950s US Federal Relocation program](_URL_1_), which moved Indian families to urban centers. By the 1980s, [47.7–48.7% of American Indians married European-Americans](_URL_0_)."
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"http://books.google.com/books?id=yCe-jE2oSNQC&pg=PA87&lpg=PA87&dq=urban+indians+intermarriage&source=bl&ots=J4VzrD4whi&sig=QKBJVDcQ9m8O7dr0OwhKtUTpcAE&hl=en&sa=X&ei=qG1lVJjyHYigyATz4YHQCw&ved=0CCwQ6AEwAg#v=onepage&q=urban%20indians%20intermarriage&f=false",
... | |
edylie | why does alcohol have the wavy/ distorted looking lines when mixed with other drinks? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/edylie/eli5_why_does_alcohol_have_the_wavy_distorted/ | {
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"Alcohol has a slightly different index of refraction to water (1.36 vs 1.3333 for water). As the fluids mix the light will take slightly different paths through the fluid which results in the wavy/distorted lines you see."
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5wr23r | Were criminals/felons in prison ever enlisted to fight during the World Wars? | If so, did they choose to go or refuse and stay? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/5wr23r/were_criminalsfelons_in_prison_ever_enlisted_to/ | {
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"At least in the WW2 they were. In Finland there was a battalion called Musta nuoli(black arrow) that consisted mainly of criminals and political prisoners. It was led by Nikke Pärmi, a convicted criminal himself. Much to everyones surprise, although I can't tell you why, many of them surrendered and jumped to Soviet side at the first opportunity, although later on they performed so well in combat that even finnish marshal Mannerheim personally congratulated Pärmi for their efforts. \nSource: Sari Näre & Jenni Kirves: Ruma sota(don't know if it's translated but the title means Ugly war)\n"
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2vl501 | Did the popularization of the progressionist, post modernist views of history in the 20th century effectively reduce the role of history as a science? | (I know this is more concerning historiography than actual history but I couldn't think of a better place to ask the question)
Lately I've been researching the different approaches to history developed in the late 20th and early 21st centuries, and it would seem that the progressive view of history was once justified, yet at this point has lessened the usefulness (or perception of usefulness I should say) of history in academia.
Generally I'm speaking of the attitudes that "every man is his own historian," there is no objectivity, truth is relative, etc. What purpose do we have for being historians if there isn't a possibility of truth? I know the assumption of no possible truth is a tad extreme but it would seem that no matter where you turn today popular, newly written historical works are very reductionist and almost needlessly contrarian to past interpretations.
What scientific value, or teaching value rather can the study of history offer if we feel the need to always teach the controversy simply to "stand out" from past generations? I realize truth is subjective and that being provocative will sell more books, but at some point it seems like history is slowing merging with philosophy or sociology rather than being an actual science on its own account.
I'm very interested in both insight into why this shift occurred in the last century and other historians opinions on the matter.
**TL;DR questions**
- Why did the progressionist view of history come about in the last century?
- Was it justified at that point?
- Are post modernism and progressivism still justifiable in the study of history?
- Do you feel like the role of history as a proper science (and therefore historians as "scientists," for lack of a better term) has been lessened?
If any of those questions are too meta then I'd simply like to understand the evolution of the study of history in the last century and the historiographical ramifications from these shifts. (Still very meta but a question nonetheless!)
Thanks for any responses! | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2vl501/did_the_popularization_of_the_progressionist_post/ | {
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"not really an answer to your question but historiography does explicitly fall within the subrules so your fine in asking it. ",
"I'd say that history as an academic discipline is slowely coming into it's own through it's interaction with related disciplines. It's not being defined by philosophy, sociology or anthropology. Through careful interdisciplinary research, these academic disciplines are working together and improving their own methods. While it's true that post-modernism added some bumps to the road, I think that's was to be expected. It ultimately forced historians to take a more rigorous look at their methods, tools and even their own frame of mind. I'd argue that the increasing importance given to historiography in contemporary history is largely thanks to post-modern arguments. What you describe sounds a lot like historical relativism, which was a direct result of post-modernist theories, and theoretical historians have been working hard to get past that. With great success so far, if you were to ask me.\n\nRecognizing that writing history is a subjective process and urging historians to be wary of their own personal frame of mind, isn't exactly synonymous with forgoing all claim to objectivity or denying the existence of 'facts'. For example, when Patrick Joyce scrutinizes the approach where employed methods and terminologies are instilled with a deterministic nature or an objective value, he isn't asking historians to do the opposite and to give in to chaos. All he asks of his fellow historians is that they employ a high degree of reflexivity and meta criticism. What you are describing in your comment is basically what happened with the Holocaust Denial in historiography. Unfortunatly, many history educations aren't very preoccupied with historiography and might be lagging behind. So it's a great question. Still, I think it's safe to say that most historians have been able to overcome that hurdle roughly ten to fifteen years ago. Wether be it by appealing to increased reflexivity or \"Internal Realism\", the solutions presented are many.\n\n > Do you feel like the role of history as a proper science (and therefore historians as \"scientists,\" for lack of a better term) has been lessened?\n\nthis is sort of a separate question, so I'll answer it as such. I don't think it has changed much. As always, everyone thinks they can be a historian. Popular opinion of history is still very much stuck on the perception of history as a list of dates and names. They have no knowledge of proper historical practice or methods and they think that it's just about telling a story. I doubt that will change anytime soon. It's very telling of our day and age, but I don't think that cultural sciences will be looked upon without scepticism anytime soon. That being said, I think we have some great minds in various branches of the cultural and social sciences working together to improve their respective fields. So as far as I'm concerned, history as a scientific discipline is doing great.\n\nIf you are interested in more, here are some of the sources I used. I could give you more titles on the subject if you so desire.\n\nSources:\n\n- Patrick Finney, *Ethics, Historical Relativism and Holocaust Denial*\n- Patrick Joyce, *The End of Social History?*\n- Chris Lorenz, *Historical knowledge and Historical Reality: A Plea for 'Internal Realism'*",
"I'm not going to engage with the first three questions you asked; I'm not really one for grand theoreticals of historiography and much prefer getting down to the 'dirty work' of history (I also have no desire to relive my compulsory undergraduate debate models *shudders*). I will, however, offer my thoughts on your last question - which may be a bit rambly and incoherent, owing to my internet disconnecting a dozen times whilst trying to write this!\n\nWith sincere respect, one of the serious issues I have with the premise of your post is that it is assumes all academic pursuits must be fundamentally scientific - in the sense that they must follow something akin to the scientific method, and following that method must reveal an objective truth if applied properly and rigorously - for them to have worth. I really don't think that's the case at all. I find it difficult to imagine how, say, English Literature or Theology could be considered particularly scientific pursuits, yet the contributions scholars in those fields have made to the intellectual, cultural and social fabric of our society has been immense.\n\nIn terms of whether history is a science, I would struggle to say that it is - but I would not go so far as to say that it is *unscientific*, either. Whilst I am slightly inclined to the post-modernist contention that it is never possible to know the completely, absolute, objective truth of the past, that does not mean that we as historians cannot develop a meaningful, worthwhile approximation of that truth. Put simply, there is an objective truth to be discovered; that is difficult to refute. Whether we can ever discover it or not is a very different question - but certainly if that truth exists, then we can at least construct a version of events that closely reflects the reality, even if imperfectly. \n\nIt is through the rigorous application of the historical method that we strive to construct that version, and we should always have in mind a responsibility to try and reconstruct the past as faithfully as possible, based on the evidence we have available to us. Dissent and debate are an important part of that process, just as they are in the natural sciences or in any other academic field; it is through considering defences and justifications for conflicting interpretations of the source material, and by constantly seeking out new material, that we can reach a meaningful consensus on a topic. Usually, when there is a shift in consensus it is because new evidence has come to light and been accepted by the historical community, not simply because we wish to make (a quite literal) name for ourselves in the history books. Indeed, a lot of the most innovative and exciting work in many fields of history is not work that seeks to challenge existing norms but work which opens up entirely new avenues of inquiry, or revisits questions that have not been addressed in a very long time.\n\nIn terms of our interaction with other disciplines, I think that this has enormously strengthened, not weakened, history as an academic pursuit. Whilst the lines do sometimes become blurred, it is certainly not the case that historians are becoming sociologists or economists or philosophers - but by engaging with those disciplines, we are able to develop a much more rigorous account of the past. If these disciplines have applications in the modern world, then they certainly are useful in helping us to understand the source material we encounter and its implications - but our method ultimately remains the historical one. If anything, engaging with these disciplines has helped ours - and theirs - to mature and develop a higher standard of scholarship.\n\nPopular history is, I think, a beast of quite a different kind to academic history. Some of it is very good, most of it is decidedly mediocre, and a great deal of it is very, *very* bad. Too few people in my experience appreciate proper historical practice and think of history very much as a factual narrative; something anyone could put together if they had the time. It can sometimes lead others to question the validity of our pursuit and lend credence to works that really do not deserve such. I have read too many popular history pieces that remind me of first year undergraduate essays - and not always strong ones! Regardless of perceptions though, and regardless of what gets published masquerading as rigorous history, academic history - including that produced by those 'amateur' historians who have a rigorous grasp of their subjects - is stronger than ever in my opinion.\n\nFinally, I would have to say that I always found the extreme subjectivist notion that history is not worth time and effort because it cannot find objective truth very odd. The past has happened, and it has had a profound impact on our lives, one that is worth understanding. If it is not possible to know the objective details of the past, then surely that makes history very important in a different way - as the only way in which we can possibly understand who and what came before us. Even if those understandings are completely subjective and have no objective merit, they are surely still valuable to us as individuals, communities and society."
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5zay1d | What is the history of William The Conqueror's title? | Conventionally, people seem to think he was "The Bastard" until 1066, whereupon he had a global official name change to "The Conqueror".
I assume he is mentioned in documents in Anglo-Saxon English, Celtic languages, Norman French and presumably legal/ecclesiastical Latin?
What do we actually know about this?
| AskHistorians | https://www.reddit.com/r/AskHistorians/comments/5zay1d/what_is_the_history_of_william_the_conquerors/ | {
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"Those aren't titles, they're \"Epithets,\" descriptive terms/phrases accompanying a name which are basically nicknames given by other people. His only real titles were \"Duke of Normandy,\" and after his conquest \"King of England.\" \n\nWilliam's epithet *The Bastard* mostly appears in non-Norman sources, ostensibly penned by people close to his opponents. There are very few contemporary written accounts describing what he was like and what people called him. "
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2rrdr2 | How did the double slit experiment explain if light was a wave or a particle? | I have general background of the experiment, but I'm confused as to what exactly it explained | askscience | http://www.reddit.com/r/askscience/comments/2rrdr2/how_did_the_double_slit_experiment_explain_if/ | {
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"Interference patterns only happen with waves. Detection of objects at point locations only happens with particles. In the double slit experiment, light (or electrons, or whatever), are shone through two slits to create two coherent beams that can potentially experience interfere. The result of the experiment is that on the photographic plate you indeed get an interference pattern, but the pattern is composed of a smattering of point-wise detections. Therefore, the light is both a wave and a particle. If it were just a particle, you would not get the interference pattern. If if were just a wave, you would not get the point-wise detections. Look at [this image of the double slit experiment perfomed with electrons](_URL_0_). You see both dots and bars, meaning that electrons are both particles and waves. You get the same kind of result with light (but you need much more sensitive equipment to actually run the experiment with light).\n\nUPDATE: As others have mentioned, the more accurate statement is: Light is neither a classical wave nor a classical particle, but is something more complicated which acts in certain ways like a wave and in other ways like a particle, at the same time. If this sounds vague to you, its not because quantum theory is vague. The theory itself is concrete, predictive, quantitative, self-consistent, and complete in its own realm. The hard part is turning the equations of quantum theory into little qualitative pictures that humans can visualize in their minds based on things they are used to in everyday life. That is where the vagueness of quantum theory arises, and that is where the wording gets clumsy. Calling a quantum object a classical wave or a classical particle, or both is not strictly accurate, but is a useful mental shortcut for humans to use in making a picture in their mind.",
"First of all, abandon the idea of the wave-particle duality - it's self-contradictory and not correct. [The wave-particle duality is an old misconception which is avoided in modern textbooks and papers.](_URL_0_) \n\nWe should be calling photons \"elementary entities\" which can be described as probability waves for some manifestations. Today it is possible to detect the arrival of individual photons, and to see the diffraction pattern emerge as a statistical pattern made up of many small spots. Stated another way, no single photon creates an interference pattern. Rather, MANY do because they form a wave-like distribution. \n\nSo what are photons? We know photons are \"fundamental\" particles that mediate electromagnetic interactions. They are wave packets of energy in the electromagnetic field which obey Bose-Einstein statistics (indistinguishable elements). Photons are not merely a ripple in the electromagnetic field, but spend some of its time as an electron field disturbance, such that the combination remains a massless particle. Photons arise as the proper observables from the field(s) when certain measurements are done; namely, energy measurements. Note that there are also \"virtual\" photons ... A charged object with an electric (and possibly also a magnetic) field is surrounded by an entourage of photons, constantly being emitted and reabsorbed. \n\nIf you want to learn more, read up on the \"Copenhagen Interpretation\" and you can also find many opinions to the contrary including Bohmian mechanics and others. \n \nHere's a [cool video](_URL_1_) which may confuse you even more ;)",
"In 1984, Richard Feynman gave a [series of lectures](_URL_0_) in which he explained why the double slit experiment showed what it did.\n\nIn the lead up to his talking about the double slit, he laid out the following properties of light:\n\n* Light arrives as a particle. Not a wave. Not a wavicle. Just a particle.\n* Light particles (photons) have a probability to be detected in some places and not others. When you plot the probabilities of where you're likely and not likely to detect photons, you get a wave pattern. \n* Photons can be absorbed by electrons.\n* Electrons can emit photons.\n* Both can travel from point to point.\n\n \nWhen you view the wave patterns that arise in the double slit experiment what you're looking at are probability patterns that arise from a set of initial conditions. When you alter the number of slits, you alter the initial conditions which alter the probability patterns displayed in the experiment.\n\n The net result is it doesn't matter if you dribble the photons one by one or by the trillion, the probability functions remain unchanged. The slit experiment is unaffected by how quickly the photons pass through the apparatus. \n\nOne way of thinking about it is to realize if you plot how two dice roll over thousands of rolls, it doesn't matter if you roll the dice quickly or slowly, you're still going to get a similar pattern\n\nWhat makes photons and electrons different than something like bullets is photons and electrons can interact with each other. That is, electrons have a probability of absorbing or emitting a photon which you can't do with bullets. Moreover, photons can decay into electrons and positrons which can recombine to form a photon. Both events are tricks a bullet can't pull off.\n\nThinking about wave troughs and peaks cancelling each other out leads you down the wrong path. Cancelling out happens but it happens way before the troughs and peaks become apparent - the cancelling happens when you look at the probability vectors that arise from the electron absorbing/emitting or not absorbing/emitting a photon.\n",
"Everything is always a wave. Sometimes, waves act like particles. Quantum mechanics provides the mechanism by which you recover particle-y behavior out of a wave (in most cases. You can get waves to act like particles in certain other cases, but they're very special and less interesting).\n\nHow does the double slit experiment fit in here? It showed that light and electrons are both waves. We already knew that electrons acted like particles. The photoelectric effect showed that light did too.\n\nIt took a while for us to mostly shake off the silly duality idea. Every time something acts like a particle, it's really just a very, very bunched up wave."
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302zxc | how are rock songs constructed? | How exactly does the guitar interact with the bass, rhythm and vocals.
I know nothing about music theory or rhythm, and I don't even know where to begin looking for a deeper understanding about how a rock song is put together. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/302zxc/eli5_how_are_rock_songs_constructed/ | {
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"Rock grew out of American folk music and jazz. Rock music covers a very wide range of sounds and styles, however. There's no good description of a genre that includes Good Charlotte, Megadeth and AC/DC.\n\nEvery band handles writing their music differently. Some start with lyrics and then work music around it, others start with a bit of music and then work out lyrics later. Some build on a guitar riff, some on a chord progression, some on a baseline, some a drum beat. \n\nSome like simple guitar parts, some do more complex ones, some like to weave many parts together, some keep it all really simple.\n\nMost of them use a mix of these approaches. \n\nThere's really no substitute for learning to play the kind of music you want to write, and working out first hand what makes it work. And there's nothing better than just writing pages and pages rubbish music to find out what works for you. \n\nNow, if you want to ask about a specific band or song I can talk about what I think makes it work.",
" > How exactly does the guitar interact with the bass, rhythm and vocals.\n\nGenerally speaking, one instrument (most often the guitar) plays a lead melody, while all other instrumentation and vocals play harmonically-compatible parts which *support* that melody. On their own these supportive instruments do not play parts that could be considered distinct melodies, as they're designed to accent the lead melody. More complex rock music, and a great deal of music from other genres (such as classical or technical death metal), will feature instruments playing completely *separate* but harmonically-compatible melodies, each of which could stand on its own as a distinct melody.\n\nIf you require more information than that, I don't think your question is really ELI5 appropriate. You'll need to start learning music theory thoroughly, and from the ground-up. And [this](_URL_0_) is as good as any place to start.",
"Most band composed rock songs start with a riff, guitar/bass/vocals. Everyone else starts writing to it, staying in the same key usually. Some can be quite complex, some simple. If the guitar riff is written first, the bass player will often start with the root notes and work from there. Some groups are into collaboration, some have writers who control the process, short of flourishes. It really depends on the band. As the song gets put together, often pieces are changed to fit. "
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63cjok | why do many college students want safe spaces on their campuses? why is it such a big deal to them? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/63cjok/eli5_why_do_many_college_students_want_safe/ | {
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"The problem with 'safe spaces' is the context it is used in - in different context, it could range from referring to a safe space as a space where certain groups of people/ideas are not discriminated against (tolerated) and allowed to be themselves (love whoever, demonstrate faith however, express whatever), it's a place where tolerance and inclusion is almost celebrated - to basically a space where ideas/opinions are censored, etc. \n\nWhat many people fails to realize is that the desire for safe spaces on campuses (as a sign of inclusion and acceptance) implies that it is not safe for certain demographics to function within certain public spaces - a lot of subtle discrimination reflected in nuances in behavior is easily overlooked by people not experiencing certain cultural biases working against them and thus conclude that there is no on-going problems with discrimination. It isn't meant to be a tool to silence ideas you disagree with (as many people perceive it to be) but it's supposed to be a public space without (unfair) hateful ideas (from cultural biases) - ideally it would be a space where people don't insult each other right away if they slightly disagree with one another but are encouraged to learn about each other's differences through discussions and eventually awareness to acceptance. ",
"Wouldn't it be a big deal to you if you felt unsafe on campus?\n\nThat is what it is about: safety. Certain people (4channers, gamergaters, MRA's and the like) want to pretend that it is about protecting people's feelings, but the clue is in the name. It is about making people feel safe.\n\nIf you're black, and the school invites a KKK leader out to talk about their beliefs, you are going to feel unsafe. Because that person wishes to harm you, and the simple fact that so many on the school wanted to hear this person means that some of your fellow students harbor similar ideas. If you're a rape victim, and students are encouraged to discuss subjects such as \"there's no such thing as rape\", you are going to feel really, really unsafe. Because you know people are literally discussing whether or not they can get away with harming people like you, and they are doing so with the school's blessing.\n\nA lot of people want to harm many different minorities in many different ways. Sometimes with physical violence, sometimes with verbal abuse, sometimes by taking away their rights. If you have to fear these things happening to you at campus, you're not going to learn much, you're not going to contribute much, and you're putting yourself at danger. That is why knowing that you're not in danger when you go to college is a big deal.",
"It's so they won't have to be exposed to uncomfortable thoughts and ideas. This is both a good and bad thing.\n\nIt's a good thing when \"safe space\" means \"I don't have to worry about feeling threatened or endangered here.\" It's a bad thing when \"safe space\" means \"I don't have to deal with thoughts, ideas, or people that make me uncomfortable.\" The former says \"We can discuss tough topics openly because we're all adults here.\" the latter says \"We can't discuss tough topics because we're still children here.\"\n\nSexual assault is bad, there's no ^[citation ^needed] about it. A college campus isn't \"safe\" from it if the entire male student body is corralled and labelled \"potential rapists\" over one incident. In fact, that makes it even less safe; the faculty's sending a message to female students that \"Men are predators and you should be afraid and suspicious of them.\"\n\nBuilding on from this, there's a difference between hosting a presentation on racism and hosting a Klan rally. Painting both with the same \"safe space\" brush delegitimizes an open and honest discussion on a sensitive topic."
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46z0jw | how does running/walking for a cause work? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/46z0jw/eli5_how_does_runningwalking_for_a_cause_work/ | {
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"one method. you as the runner/walker go and beg people to donate money for each mile that you run or walk. \n\nanother method. you pay to run or walk for the cause. ",
"Basically to participate in those thing you have to raise some money. Either from other people or pay it out of your own pocket.Some of those money goes towards charity that even it held for. Then you run/walk to show that you participated, and contributed. Not sure if there prizes for the people who comes first. ",
"It is a fund raiser, runners/walkers pay in registration fees that help go toward the race and also some of that money goes toward the cause. Sponsors agree to pay in so much to the cause in return for the advertisement of sponsoring the race. The event raises awareness and there are places to donate when people come to watch the race. "
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eyigg8 | Does a Tesla’s (car) battery die faster in extremely hot or cold climates like our phone battery? | askscience | https://www.reddit.com/r/askscience/comments/eyigg8/does_a_teslas_car_battery_die_faster_in_extremely/ | {
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"Tesla batteries are actively cooled (using a radiator just like in a conventional car).\n\nThey might be slower on startup if cold (the system should limit current), and also if very hot (such that the cooling system can’t cope).\n\nOverall capacity should not be affected given they will be warm by the time you fully discharge (or charge) them."
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1myd8v | electronic device battery charge indicators? | What process tells the software what level of charge a battery is at? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1myd8v/eli5_electronic_device_battery_charge_indicators/ | {
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"Batteries provide a constant output of power. Though the amount they put out drops slightly as it's charge decreases. The software monitors this drop in output and uses it to extrapolate the remaining charge level."
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1v3788 | having a family member who is once or twice removed? | Can someone please explain what this means... and what they did to get themselves removed at one point in time..? My dad tried explaining how some of my cousins were "once removed" but I still don't understand what it has to do with removal. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1v3788/eli5_having_a_family_member_who_is_once_or_twice/ | {
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"Removal doesnt mean \"taken away\" it mean \"distanced from generationally\".\n\nFor instance, if your first cousin (your parent's sibling's child) had a child, that person would be your first cousin once removed. If that person had a child, they would be your first cousin twice removed.\n\nWikipedia has some pretty charts that will help, I think: _URL_0_",
"I'll state this in a few different ways:\n\n* My sibling is my sibling.\n* Our respective children are first cousins.\n* Our respective grandchildren are second cousins.\n* Our respective great-grandchildren are third cousins.\n* Our respective great-great-grandchildren are fourth cousins.\n\nWho is the common ancestor:\n\n* Siblings have the same parents as you.\n* First cousins have one pair of the same grandparents as you.\n* Second cousins have one pair of the same great-grandparents as you.\n* Third cousins have one pair of the same great-great-grandparents as you.\n* Fourth cousins have one pair of the same great-great-great grandparents as you.\n\nThe number of \"greats\" in the grandparents who are the same:\n\n* First cousin = 0 greats\n* Second cousin = 1 great\n* Third cousin = 2 greats\n* Fourth cousin = 3 greats\n\nCommon ancestor distance:\n\n* Sibling: 1 generation back\n* First cousin: 2 generations back\n* Second cousin: 3 generations back\n* Third cousin: 4 generations back\n\net cetera...\n\n\"Removed\" means that the two of you have a different number of generations back to your common ancestor. If our common ancestor is three generations back for me and five generations back for you, our relationship as cousins would be twice removed. My first cousin's child would be my first cousin once removed. I would be their second cousin once removed.\n\nSomeone can also be a \"double-cousin\" if one of your parents is one of their parent's siblings and if your other parent is also their other parent's sibling."
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86rmll | why do electric cars have a lower range when it's cold? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/86rmll/eli5_why_do_electric_cars_have_a_lower_range_when/ | {
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"Batteries rely on chemical reactions to provide power. Cold temperature slows down those reactions, giving you less power",
"That's for two reasons:\n\nFirstly, in colder weather, it is more difficult for electrons to move through the battery, so many electric cars will have a climate control system exclusively for the battery for optimal battery performance at the cost of range.\n\nSecondly, unlike gas engines, electrical engines produce much less heat energy (thus why they are more efficient), which would normally be used to keep the inside of the car warm. In electric cars, because the engine doesn't make a lot of heat, the climate control will be used a lot, and that power comes from the same better that drives the car, thus reducing the range. If the climate control isn't used, then there's hardly a difference."
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4wm0zi | Were bronze swords reused through many battles? | Were bronze swords ever reusable through many battles, and were they generally constructed (within organized militaries) to last for a full campaign? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4wm0zi/were_bronze_swords_reused_through_many_battles/ | {
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"Bronze swords were certainly reusable: examples have been studied from Denmark, Croatia and Hungary which show signs of repair.^1 Whether they were deliberately constructed with campaigns in mind is a harder question to answer - and would depend on what a \"campaign\" would consist of. Given the high levels of edge damage that have been observed on some bronze swords^2 it seems likely that repairing swords would have been commonplace, and so could be carried out as needed.\n\nMy knowledge is mostly based on prehistoric Europe, where records that would allow us to know about how militaries constructed swords are generally absent. Written records from the Near East or NE Africa might have some information on the manufacture of swords - perhaps someone else here could comment on that? \n\n^1 Kristiansen (1977) \"The Circulation of Ornaments and Weapons in Bronze Age Denmark\" *Archaeologica Baltica* 2; Kristiansen (1984) \"Krieger und Häuptlinge in der Bronzezeit Dänemarks. Ein Beitrag zur Geschichte des bronzezeitlichen Schwertes\" *Jahrbuch des Römisch-Germanisches Zentralmuseums Mainz* 31; Harding (1995) *Die Schwerter im ehemaligen jugoslawien* p.34; Kristiansen (2002) \"The Tale of the Sword – Swords and swordfighters in Bronze Age Europe\" *Oxford Journal of Archaeology* 21.\n\n^2 Bridgford (1997) \"Mightier than the Pen? (An edgewise look at Irish Bronze Age swords)\", in *Material Harm: Archaeological studies of war and violence*."
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5mbn0v | Can you identify this ship? (Circa WWII-1950s?) | Hi, Historians!
_URL_0_
I received this photo from my mother, who has requested help in identifying anything about the ship.
Here's what she had to say about the photo:
"The negative for this photo was in amongst Dad's stuff, and I wondered what the significance might have been. I don't know where it was taken and there aren't any identifying markings on the ship that I can see.
The negative is approximately 6 x 6 cm and is labelled Kodak Safety Film. I have a number of photos on similar negatives of me taken around 1954-56, some of grandma and grandpa when they were on their honeymoon in 1950.
From that I gather that the ship might have been off the coast of Anglesey, or Cardigan Bay, or on the South Coast in the Portsmouth area.
Failing that, Dad served in Ghana during the second world war.."
Thanks in advance for your help! | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/5mbn0v/can_you_identify_this_ship_circa_wwii1950s/ | {
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"The side profile matches an [Iowa-class battleship](_URL_0_), although I can't seem to discern which of the four (Iowa, New Jersey, Missouri, Wisconsin) this one is due to the identification number near the bow not being visible. u/DBHT14?",
"Sure so if I was a betting man I would say in order or likelihood for the 4 of which one it was would go:\n\n1. Wisconsin\n\n2. New Jersey\n\n3. Iowa\n\n4. Missouri\n\nAll 4 ships did spend time in European waters after the war but Wisconsin and NJ made the most trips both hosting summer training cruises for Midshipmen in the late 40's. Then after service in Korea as surface combatants in the fledgling NATO naval element. Wisconsin notably participated in Exercise MAINBRACE, the first real joint NATO large naval exercise in 1952, while Iowa joined her for STRIKEBACK in 1957. ",
"OK! \n\nSo I think I am going to reassert my original assertion that it was most probably Wisconsin.\n\nI got this by looking at the radar set on the mainmast, and seeing the very distinct SPS-8A radar. \n\nNavWeps then was very helpful in showing when each ship got what radar on what mast. _URL_0_\n\nWisconsin got hit first in 1952, Missouri and New Jersey both in 1954, while Iowa only got a set in 1958. ",
"I'd like to send a HUGE thank you to /u/the_howling_cow, /u/DBHT14, /u/diggerhistory, and /u/kieslowskifan for all of the wonderful responses and information.\n\nMy mother and I have spent some time going over all of your information and doing some reading up on these ships ourselves. We have discovered that we have another negative of a picture of this ship, at a slightly different angle, in which we can see open water both at the front and back. We're going to try to get this second negative scanned and hopefully we will be able to see the numbers on the ship! We will absolutely let you know if we come across further information.\n\nWe feel that it is likely that this picture is from Portsmouth and very likely the ship is in The Solent. We noticed as we were looking at it more closely that the deck appears to be lined with sailors, so they may have been arriving at port or leaving from? If the picture was taken in Portsmouth, the date of the photo would have been between 1954-1957, as that is the time period in which my grandparents lived in Portsmouth.\n\nThank you all so much. You guys are completely awesome. :)"
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qqpy1 | If a tree is planted and given infinite resources, in perfect growing conditions at all times, can that tree grow forever? Or does it hit a limit and die of old age? | I'm pretty much trying to find out if a plant put in perfect conditions and is at all times in a constantly changing environment that supports perfect growth. Would it grow forever or stop at one point and die? | askscience | http://www.reddit.com/r/askscience/comments/qqpy1/if_a_tree_is_planted_and_given_infinite_resources/ | {
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"There is a limit to how tall a tree can grow, mostly due to [hydraulic constraints in getting water from the roots to the branches](_URL_2_).\n\nIn terms of age, bristlecone pines are the oldest non-clonal trees, with [Methuselah](_URL_1_) holding the record at just under 5000 years. [Clonal](_URL_4_) tree systems can grow even older, with an 80,000 year old Quaking Aspen system called [Pando](_URL_0_) holding the record for oldest and heaviest (6,000,000 kg) organism.\n\nEdit: [King Clone](_URL_3_) is also kind of awesome, having been dated more precisely with dendrochronology.",
"Aside from the other comment, wouldn't the tree eventually get cancer? (Laymen's question)",
"Depends on the species. Some species will grow for 10-20 years and then slowly lose vigor (making them not suitable as 'heirloom' bonsai trees intended to be kept for generations). Other species don't seem to have this problem.\n\nYou might need to periodically prune the tree's branches and roots, since trees do best when they're actively growing and there are upper size limits. ",
"In some cases, harsher conditions make for older individuals, even though the average lifespan and especially the median lifespan are much lower.",
"There is a limit, funnily enough its actually a physics question. It all depends on how much the tree can battle gravitational potential to get water to its branches. This maximum height figure was calculated, based upon the idea that the tree used air pressure/suction to get water to the top. But how a tree gets water up there is not a known fact but there are a few best guesses (and with a little experimentation we shall soon call one fact). Each of these guesses resulting in a different maximum height.",
"[Paper Birch, aka. White Birch (Betula papyrifera var. papyrifera)](_URL_0_) live about 80-100yrs. My wife and I made this personal discovery across a 10yr time span. In the 90s we toured around Lake Superior in the United States and Canada, one thing that was remarkable was the beauty of the huge White Birch in Minnesota and Wisconsin that lined the lake. 10yrs later when we returned to the same area, most of those glorious stands of Birch were now a shadow of their former glory. After some research, we discovered that most of them were planted in the [early 1900s](_URL_1_) after the White Pine logging days. Since they had mostly been planted around the same time and had reached they end of their natural life cycle with the addition of some natural stressors, there was a massive die-off. It will be a very long time before the forests fully recover.",
"I had the a question along the same line. Can a person take a cutting from a house plant, repot and take a cutting from that plant, repot and so on indefinitely? Will this plant live forever through infinite cuttings or will the plant die at some point in time. Not explained well but hope someone understand.....\n",
"While cuttings bring up an interesting possibility, I'm curious about the potential of bonsai. It seems that by containing the roots and height of trees one could possibly avoid the issue of hydraulic constraint. I'm not speaking from any particular knowledge base. It just seemed like an interesting thought. Any thoughts?",
"Each time a cell divides, mutations can happen -- including telomeres (which are regions at the end of chromosomes, which are made up of DNA) getting shortened. So over time, these regions get shorter and shorter. Eventually they will get so short that the cells would die. Cells can't live forever, there is a limit observed in most cells because of this telomere shortening process known as the Hayflick limit",
"Hello, I am a forester and fairly well qualified to answer this question. Trees do grow old and die. Overall growth of a tree, x=age y=height, resembles a sigmoidal form, like most living things. As such, the derivative of that function is the rate of growth, or periodic annual increment as foresters often call it. There is also mean annual increment which is total growth to date divided by the age of the tree. A tree is often thought to reach maturity when PAI = MAI, though I am sure that is debatable. Anyways, when a tree reaches maturity, how large it is when it reaches that point is a function of several different factors including the specific species, how well the site meets the needs of the particular species, and lots of other more marginal factors such as the genetics of the species.\n\nSo you are asking given totally ideal traits, will a tree grow forever? The answer is no, all trees more or less die at some point, though many trees are coppice sprouters like Redwood. \n\nAn interesting question that I just thought of is this: Do trees actually live shorter lives given absolutely ideal conditions? I am a tree farmer, not a botanist, so I am not exactly sure. One thing that I can tell you for sure is that trees reach commercial maturity at a younger age the more ideal the environment is.\n\nAlso, trees like the redwood are more or less freaks of nature. That's a major reason why there has been so much interest in them lately. Compared to most trees, they are extremely resistant to disease, they grow to outrageous heights, they are coppice sprouters, they seemingly suck water our of the air, their heartwood has incredible anti-microbial properties, the list goes on and on. The MAI/PAI curves for Redwoods fly in the face of standard wisdom about the silvics of trees and their CMAI (mai=pai) is hundreds of years past CMAI for most species.",
"This made me want to ask another question. Would the tree in question have rings if you cut it down considering it was in perfect growing conditions at all times?",
"On a slightly-tangential note: according to this page on Wiki: _URL_0_ there are several animals that don't show higher mortality rates as they age. Does this mean that these animals could, under the right conditions, live indefinitely?",
"Some trees are able to reach an equilibrium and live to [extremely old ages](_URL_0_).\n\nThere is a [tree in Sweden](_URL_1_) believed to be over 9000 years old. The article states that it survives by growing a new trunk when the previous trunk dies. In that way, it does not end up being a huge tree overall, but the roots keep living.",
"OK -- It's an hour long (but worth it and somewhat relevant). RadioLab podcast from a couple of years ago (called: \"Oops\"). Did this episode pop into anyone else's mind? _URL_0_\n\ntl;dl; man cuts down tree ... gets a nasty surprise",
"According to [this article](_URL_0_), the root system of a Swedish conifer has been growing for 9,550 years.\n\nWhether or not that \"counts\" is left for the reader to decide.",
"well, it depends on how you look at it. A tree in its entirety (roots, trunk, branches, and leaves) will eventually die at one point because, like others have said, water won't be able to the top of the tree due to its height and gravity. However, a tree's presence can be forever because plants can clone themselves. You can take a root of a tree and grow another one that is genetically identical to the tree it came from. In fact, there's a tree that is a few acres large because it cloned itself. That is the root sytem is giant, and its sprouts are what we can see from it and we think of the sprouts as trees, but in fact, they are all the same.",
"sorry if this is a little off topic, but why is that prehistoric trees are so much bigger and taller? \n\nDoes the higher level of oxygen during those times have anything to do with it?",
"I'm no expert in this field by any means but from what I understand about the cellular replication of DNA i believe this may have some importance/relevance to why the tree may eventually begin to die. As our cells replicate our DNA incredibly fast, the proteins responsible for replication also frequently end up cutting off bits and pieces from the ends of the DNA. This is why in our genetic code all of the important bits tend to be in the middle. The stuff at the end typically has little/no significance. However, as we get older those bits and pieces from the end add up and its believed that the bits and pieces at the end which get cut off are now near/cutting into our important DNA. Thus, it is believed that one of the major reasons for aging could potentially be this fact. This too likely occurs in trees and all other organisms because they too need to replicate DNA in order to grow. As to why the trees live longer than us I can not say. Perhaps they replicate slower so it takes longer for the ends which get cut off to reach their important genetic material. \n\nAn interesting side-note: The protein telomerase is linked to re-creating the ends of our DNA so that the important genetic material is not reached. However, telomerase is present in fetal humans (not-active in adults) which is note worthy because if the ends were not built back up then the offspring would be left with the DNA already much shorter than that of the parents. Also, telomerase has been found in cancer cells which may explain their uncontrolled growth. \"If telomerase activity was to be turned off, then telomeres in cancer cells would shorten, just like they do in normal body cells. This would prevent the cancer cells from dividing uncontrollably in their early stages of development.\"\n\nHope all my facts are correct. I know you guys will let me know if I'm wrong. :)",
"Many of these answers say that the tree would stop growing, but could it stay alive at its maximum height indefinitely?",
"The ONLY immortal creature on the earth is jellyfish."
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"http://en.wikipedia.org/wiki/King_Clone",
"http://en.wikipedia.org/wiki/Ve... | |
ltc1i | how goldman sachs is ruining the world. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ltc1i/eli5_how_goldman_sachs_is_ruining_the_world/ | {
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"It's not explaining LY5, but [this Rolling Stone article](_URL_0_) is pretty thorough. One of those rare many-paged articles that's actually worth reading all the way through.",
"It's not so much that they alone are ruining it. It's more that they're a very useful accomplice to those that are, and that they happen to be making a lot of money while accomplicing...[sic]",
"It's a variation of \"Money = Power\". Goldman is good at a) making money; b) raising money. People are willing to stretch their morals and ethics for money and power.\n",
"I don't know if Goldman Sachs necessarily is ruining the world, but they seem all too happy to help people who are interested in such, and don't mind bending the law in order to do it.\n\nCase in point - in 2007 a hedge fund named Paulson & Co. Inc. put together a CDO with toxic mortgages and asked Goldman Sachs to sell it for them. Paulson & Co. Inc. was a company known to short the mortgage market, which means they were expecting it to lose money. So you aren't going to run off and pay top dollar for mortgages hand picked by these guys.\n\nBut here's the deal - Goldman Sachs didn't tell the people they were selling the CDO to that it was put together by Paulson & Co. Inc., something which they are required to do by law.\n\nThe SEC filed a criminal complaint, Goldman Sachs said the lack of information was a mistake, and paid a half billion dollar fine to have the case dropped.\n\nThat may not seem like an example of ruining the world, but to the people who invested in the CDO and saw their entire investment virtually disappear because of Goldman Sachs withholding information they were legally obligated to share, they might find it more grievous.",
"It's not explaining LY5, but [this Rolling Stone article](_URL_0_) is pretty thorough. One of those rare many-paged articles that's actually worth reading all the way through.",
"It's not so much that they alone are ruining it. It's more that they're a very useful accomplice to those that are, and that they happen to be making a lot of money while accomplicing...[sic]",
"It's a variation of \"Money = Power\". Goldman is good at a) making money; b) raising money. People are willing to stretch their morals and ethics for money and power.\n",
"I don't know if Goldman Sachs necessarily is ruining the world, but they seem all too happy to help people who are interested in such, and don't mind bending the law in order to do it.\n\nCase in point - in 2007 a hedge fund named Paulson & Co. Inc. put together a CDO with toxic mortgages and asked Goldman Sachs to sell it for them. Paulson & Co. Inc. was a company known to short the mortgage market, which means they were expecting it to lose money. So you aren't going to run off and pay top dollar for mortgages hand picked by these guys.\n\nBut here's the deal - Goldman Sachs didn't tell the people they were selling the CDO to that it was put together by Paulson & Co. Inc., something which they are required to do by law.\n\nThe SEC filed a criminal complaint, Goldman Sachs said the lack of information was a mistake, and paid a half billion dollar fine to have the case dropped.\n\nThat may not seem like an example of ruining the world, but to the people who invested in the CDO and saw their entire investment virtually disappear because of Goldman Sachs withholding information they were legally obligated to share, they might find it more grievous."
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6f9qds | why do chip card transactions take so much longer to process than magnetic strip transactions? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6f9qds/eli5_why_do_chip_card_transactions_take_so_much/ | {
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"You're right, chip cards do take longer. According to the [Chicago Tribune](_URL_0_) here's why:\n\n > The delay is due to the added security features, the primary reason for using the technology. Specifically, the chip in the card is generating a unique encrypted message between the store and the bank's network.... All of this is more secure than the old slide-card technology ",
"It's an Infrastructure Issue.\n\nChip Cards have added Security Features. These features are meant to make forging a Chip Card *incredibly* difficult, even if you manage to get a Skimmer working for them. However, more complex security features require more Computer Processing to verify and authorize.\n\nThe Chip Cards are new, and they're running on the older hardware made for Swipe Cards. This hardware isn't fast enough to do Chip Cards as quickly. You've basically traded some Time for Security.\n\nChip Card Transactions *will* become faster as the Infrastructure is improved. It's just a matter of waiting for companies to get that Infrastructure set up.",
"Chips take longer because the security is in incredible amounts, and therefore, because every machine that reads them insnt a high-grade supercomputer, it takes longer for a weaker machine to process as much information as it is providing for you to use your card.",
"Two reasons: 1.) Chip cards encrypt the information. Think of it as a code, it takes a while to take a normal message and turn it into a coded message. It also takes a while for someone else to decode the message. It would be a lot faster just to write the message out in plain text and then give it the other person, but if anyone grabbed it, they would be able to read that message.\n\n2.) Chip cards have a secret handshake. Now that the message has been encrypted, before handing it to the other person, they first must verify that the person they are handing it to actually is the person they say they are. This is done by a secret handshake between the chip card and the person. This secret handshake takes time to do.",
"Do you have contactless payment with debit cards in the USA yet? Just touch the machine with the card and beep, 3 seconds on wifi it's approved? Anything up to £29.99 is pin free. Guaranteed by the banks. Works a treat in U.K. ",
"Mag stripe is an info dump. Machine reads the stripe, grabs what it needs, then throws that up to the processor who gives the thumbs up or thumbs down.\n\nChip and Pin is more complex. Behind the chip there is a computer, and the computer needs to encrypt the message. Due to this there are two trips that need to be done to the processor.\n\nSo in short, there's more going on when you use EMV (Chip and Pin) than with a mag stripe. This more stuff takes more time.",
"At my store the chip reader takes about 5 seconds. I think it depends on the terminal setup. We have a stand alone terminal hooked straight to the internet. We hand input the amount into it. Maybe the slow ones go through the business' infrastructure, slowing it down.",
"As a cashier operations supervisor, I get this complaint a lot. I had a feeling it was a myth. So I actually timed about 50 transactions from the moment the card was swiped or inserted, depending on type.\nAssuming their is no \"user error,\" they take about the same amount of time. Thing is, the consumer actually pays attention to the card reader while the card is in a chip reader so they don't forget their card. With a swipe, the consumer can swipe and forget. The \"extra time\" is an illusion.",
"In the U.K. Under a set amount all you need to do is tap your card on the terminal and it's done about 3 second.",
"As someone who worked in retail, they don't take longer.... anymore. They took way longer at first because of the transition, but now they are actually faster or just as fast. People just have a hard time letting go of the stigma of it being slow. Maybe they are still figuring it out where you shop, but that shouldn't last.",
"tripped me the fuck out the other day i had a customer from the US and he had to swipe and and the sign the receipt. first time i ever saw that with a customer. Everyone here either has contactless or swipe with pin. (New zealand)",
"My store has tap and pay, chip readers, and brand new pin pads, all running on Internet that has the equivalence to LESS than that of dialup.\nSo generally they bought rims for the car, but didn't wanna put gas in it.",
"Credit card applications solution architect here.\n\nFirst of all, think a chip card as a small memory device which stores its own software code in the chip and decides what to do. Several security steps like encryption, decryption, generating security data etc needed to be completed using that code to ensure completely secure financial transmissions. Furthermore the terminal communicates with your card, verifies it, and executes the code stored in it which your bank stores in your chip while issuing your card. Even your bank authorizes your purchase, your card can deny it thanks to the software code stored on it. This all takes some time. Even in some cases your bank sends some new code (called scripts) for your card to execute and along with execution, writing the output to your card takes some time too.\n\nMagnetic stripe transactions do not honor many security rules and only work with your card number, transaction amount and terminal information. That's why when your card number, and expire date are stolen, it's very easy for a third party to use your card and purchase online."
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4gl0tc | how do video game sales work? | I assume that Steam can't just cut half the price off of a game whenever they feel like it, but do they really have to get every single game creator's permission to put their game on sale? (I can imagine this'd be a nightmare during the summer sale) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4gl0tc/eli5_how_do_video_game_sales_work/ | {
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"Steam and the publishers work together on those sales. Steam does not have pricing power over the games it sells. On the other hand, if you sell things on Steam, you actually have to go through Valve to do your own sale - you can't just change the pricing yourself.",
"It's not really as much of a nightmare as you'd assume. Game publishers know that sales are coming up, and can give Valve permission months in advance if necessary. It wouldn't surprise me if Valve just has a standing email list of all the publisher's marketing departments that they can use to send out what essentially amounts to a legal permission slip before each sale."
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4u5vl7 | how is it possible that data doesn't weigh anything? | Think of all the data in the world. How come if it's on a (admittedly massive) hard drive, the hard drive will weigh the same even if the data is deleted off it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4u5vl7/eli5_how_is_it_possible_that_data_doesnt_weigh/ | {
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"You aren't adding anything or taking anything away when you delete things. All a computer does is change the current state of something, almost like millions of little switches that are either on or off. if it is flipped off, it doesn't magically start weighing less.",
"Let's say that we have a bunch of bottle caps laying on a table in a big grid, just bottlecap after bottlecap, red on top, silver on the bottom. \n\nIf we turn some of the bottlecaps over, we can draw a triangle. Now the bottlecaps are storing data (a picture of a triangle). But they're still the exact same bottlecaps, and weigh the same as they did 'blank'.\n\nComputers store 'data' as a pattern of switches. The switches weigh the same whether they're switched on or off. But once all of the switches are being used to store something, if you want more data you need another hard drive, and that will have weight.",
"does a light switch weigh more when it's on? does a bead weigh more on one side of the abacus than the other? nope, and that's why data doesn't necessarily weigh more. just a bunch of 1s and 0s, and 1s don't weigh more than 0s.",
"Sometimes \"data\" does weigh something! [A charged capacitor weighs more than a discharged one](_URL_0_). So if data is stored in volatile memory, it does have a little bit of weigh, although not very much.\n\nIn the case of a hard drive, or a solid state drive the data is not stored as a charge. Imagine the drive has being billions of very small switches. The data is stored by flipping the switch. No matter how you flip the switch, it weighs the same!",
"I stole this: \"higher information content correlates with a more energetic configuration and this is true regardless of the particular type of storage... Now, as per Einstein's most famous formula, energy is equivalent to mass.\"\n \n \nIt's a miniscule difference, you would need a very high precision scale to accurately tell the difference. An electric charge (even magnetic) carries with it mass. Those electric charges are recorded for long term on magnetic cylinders. \n \n \nRam (not your harddrive) is volatile memory, which means it loses its charge and whatever values in memory when it loses power. That type of memory will always be the same mass or weight when power is not running through it."
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9busg5 | Why didnt the B-29s that attacked Hiroshima and Nagasaki have fighter escorts? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/9busg5/why_didnt_the_b29s_that_attacked_hiroshima_and/ | {
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"Because there were daily reconnaissance missions flying over Japan at that stage of the war which the Japanese ignored, and the atomic bomb missions relied on the plane's similarity to those missions for surprise. u/restricteddata talked about this when the question was asked earlier this year: \n\n_URL_0_\n"
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5ai1l8 | why are there so many conflicting scientific research, especially in fitness/nutrition? how do we know which one is true? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ai1l8/eli5why_are_there_so_many_conflicting_scientific/ | {
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"These days researchers get paid, and get recognition for having researched published, they can also get paid to do research. Companies can also be selective of what results they publish, and when it is bublished, media companies or marketers can take that info and spin it in a way to make it click baity, or make their product look better. So it is really difficult to figure out what is true, what is false, and what has been omitted from research. I even find ot hard to beleive some goverment research. \n\nA good way to know how factual research is, is to find out who paid for the research, and to find stuff that has been reviewed, or has reseach from other organizations that came up with similar results. Also, don't beleive some hot blond women who tells you they found a root in the amazon rain forrest that cures hemorrhoids, common sense helps. ",
"There is conflict in studies about nutrition because a) the body is a very complex biochemical factory and b) there are vested interests who want to muddy the waters and c) we simply don't know everything d) people apply their existing knowledge to a subject more complex.\n\nFor example /u/sexuallemon below has applied a (valid in that discipline) scientific principle from another discipline and extrapolated it on the assumption that \"energy is energy\" (and no offence to sexuallemon it's a common error). This error is based on the original definition of \"calorie\" which was based on how much it heated water when burned.\n\nUnfortunately your body doesn't work that way, it doesn't neccessarily extract all of the *potentially available* calories, if they're wrapped in an indigestible way or your body is missing key vitamins to metabolise it, it will go straight through.\n\nSugars and high GI carbohydrates are very easy to metabolise, low GI (Glycaemic Index) foods are metabolised more slowly and often less completely. Fibre is mostly not metabolised particularly well at all but as we know - wood (cellulose fibre) burns and hence has \"calories\".\n\nThen there is the complex biochem thing, for example you have a trigger in your gastrointestinal tract that signals saiety based in part on how much fat you have eaten. If you've only been eating carbs you won't get that hormone trigger making you more likely to over eat. Then there is a bunch of complexity around hunger and insulin levels that new science is coming out about regularly now.\n\nJust to make it more complex, you're a symbiote - you carry millions of bacteria in your gut that help you digest your food (your mum was right, eat your yoghurt and eat your greens, they need it). The *particular* combination of bacteria will determine how well you can metabolise certain foods. Evidence now even shows that the wrong combo of bacteria will cause you to get fatter without changing your diet (faecal transplants are now being doing to stave off serious C. Diff infections, and studies on rats plus the actual results on humans show a skinny person will get fat if transplanted with the biota of someone obese - but hey it beats being dead).\n\nThen lastly, people make shedloads of money off making people confused so you buy THEIR book\n\nSo as a rule of thumb. Eat a balanced diet - which is NOT the food pyramid common in the 70s- 90s (it comes from a bunch of bad research that has been now rejected but it's hard to get the message out). \n\nA balanced diet means a substantial amount of your intake is raw or lightly cooked vegetables NOT including potatoes (high GI nearly pure carbs) and a balance of protein (preferencing whitemeat and oily fish if you're a meat eater) dairy, carbs and fruits.\n\nThings not to do, don't drink fruit juice, you might as well drink coke (chock full of sugar), avoid processed meats (yes that includes bacon :-( avoid sugar\n\nThere is solid peer reviewed evidence for everything above. More than that and we start getting into the conjecture part because we don't know or the obfuscation part because I want to make money off you\n\nEdit: corrected resistant bacteria from MSRA to C. Diff (Clostridium difficile) brain fade error thanks to /u/gatz for spotting\n\n\n",
"They're all *true* -- in that they all report results that were found. However most scientific research isn't easily generalizable all by itself, particularly when it comes to applying that research to individual humans and getting particular results. ",
"What other answers are missing is that reports written by newspapers, magazines, and websites telling you about a new study and what it found, are often fundamentally wrong in their summary of the study and its conclusion.\n\nIt's worth just once going to the trouble to find and read the whole scientific study relating to a web story you find interesting. You're likely to find the stunning conclusion reported in the mass media is actually very conditional (eg the effect only occurred in male mice that already had cancer, and didn't affect the female mice) or maybe doesn't even exist in the study at all and was just a random idea the scientist mentioned in one sentence.",
"In my opinion, marketing plays a large part of it. \n\nHave you ever noticed, almost like a TV show... there is always a \"bad guy\" in the food world?\n\nEveryone screams about the \"bad guy\", and new foods (that happen to be more expensive and higher margin) are sold without the \"bad guy\". \n\nOnce the buzz dies down, a new \"bad guy\" is introduced and the old one slowly fades away. \n\nFat (this one was brilliant and seems to have pretty much started the trend)\nSalt\nSodium (When \"salt\" died down they just changed the name. \"Sodium\" sounds more threatening anyway)\nMSG\nTrans Fat\nCorn syrup vs. sugar\nGluten\n\nNow we seem to be shifting into the production of foods as the bad guy. \"Cage free\", \"free range\", \"organic\", \"grass fed\", \"farm raised\", etc. \n\nOr perhaps that's just a sub plot, and the next bad guy is just a paid study or two away. Stay tuned. ",
"This is how science works. Unless you want to volunteer to be locked in a room and [fed only yogurt for 6 months](_URL_0_), researchers can't control all the factors involved in human health studies. The truth gradually emerges over the course of time, when many different studies are combined. This isn't a problem for scientists, because the preliminary studies almost always say something like this at the end: \"our findings require further confirmation and clarification by other studies\", like the one I linked. The media, however, normally does not include that qualification.\n",
"Humans are not all alike. You've probably noticed that we all look unique and have learnt that no two humans share the same dna. There is more far more variety in humans than 2 sexes and 4 blood types. We use our bodies differently, we live in ecosystems, etc. even though we are the same species nothing holds true for every person... except may be that we all have opinions. \n\n\nI do not believe there is one diet that works for everyone. There are certain aspects that many diets outline such as: exercise regularly, be hydrated, eat yer veg, cut back on soda and processed foods, eat in moderation, etc. These repeated things are more likely to be universally helpful but not always (fat is not evil). You have to be mindful of your body and find a diet and fitness regime that suits it. If you have allergies, are pregnant, sit at a desk all day, are old, whoever! your diet and fitness needs are going to be different. ",
"First why are there conflicting studies. To do a study you need money which you either have or have influence over people with the money (governments). And you need a reason for doing it. Most of the people with the money and reason are not looking for the way to stay healthy but instead that their food or product is not harmful. So first there are a lot of studies with the goal of proving something just isn't bad, so sugar doesn't kill you and you can eat sugar and not get fat gets found. Still doesn't mean it's healthy or has the possibility of getting you fat. See the issue there, that is just 1 of many problems. \n \nSecond Many studies are very broad due to I want to say limited ability to do invasive testing. People are people, you can't put them in a lab with probes attached for a year and monitor the complete response of every system with everything they eat. So we have studies that monitor people over the years and we get correlations between things instead of causal relationships. \n \nSo like some others have already said it's hard, the body is very complex and there are many factors that inhibit in one way or another effective study of it. \n \nNow with all that, we are still making progress although a bit slow. There was a pretty bad mix up in the 50s and 60s that we are still feeling the hurt from but I will ignore that. Also as far as healthy eating I don't know too much but what makes us fat is something I have looked into for a long time now. \n \nWhat we do know is that insulin is the hormone that makes us fat, it tells our cells to start to take up blood sugar and other things for energy and regulates our bodies energy. You might think that's fantastic so how do I control my insulin? Well we don't really know, as far as I know there has not been any major study that has measure insulin responses in people based on different foods and genetics. There are some people out there, usually body building people that have done some more personal tests, but it's not wide scale enough to say anything general. \n \nAs related to studies most insulin stuff is related to diabetes and not healthy eating/weight loss. Because of this there really hasn't been any studies centered around controlling insulin response in the body because doctors use insulin to regulate the patient. So if there is not enough insulin they don't care about making the body make more (which is Diabeties type 1, can't make it) they just give you a shot of insulin. It's treated as a medicine. \n \nThis is where I am at after looking into this stuff for about 5 years on and off. I am not a doctor it was just for personal understanding of the situation. ",
"The key is understanding the subtle difference between these statements:\n\nA: \"This result only has a 5% chance of happening by coincidence\"\n\nB: \"This result only has a 5% chance of being a coincidence\"\n\nStatement A doesn't say anything about how likely it is there's a real effect. Maybe the odds are only 0.01%. In that case, even though both explanations are unlikely, a coincidence is still much more likely.\n\nOn the other hand, statement B implies there's a 95% chance the effect is real.\n\nThe problem is that scientific studies almost always mean statement A, but people often confuse it with statement B, which is a much stronger statement.\n\nIt's actually very easy to generate results that only have a 5% chance of happening by coincidence. If you measure 100 things, then each one will, on average, be correlated with 5 of the others by pure coincidence. That's 5 *each*, so 500 possible headlines can come from one small study. It's so easy to do that [someone made a website that does it automatically](_URL_0_). My favorite: Per capita consumption of mozzarella cheese correlates with civil engineering doctorates awarded.",
"I'm a science grad student, not studying nutrition but I know enough that I can tell when people are reaching with science for a reason to eat or not eat something. I have been curious about food for the last 5 years or so; where it comes from, what makes it bad or good for you, how to cook it, etc. I've found that Michael Pollan is a great author to read to learn about food, and he had a nice rule that he wrote: \"Eat food. Mostly plants. Not too much.\" He wrote a quick little 60 page book called food rules where he defines the terms in this sentence pretty specifically, but I think it makes sense to me.\n\nIn terms of common nutrients like salt, sugar, fat, carbs I think everyone has heard that they're both good and bad in a dozen different ways. It can be frustrating not knowing what's healthy! Trends or lifestyles like vegetarianism, veganism, paleo, raw foodies, even a fad like juicing (god forbid) may point you in the right direction but ultimately there will still be a number of exceptions.\nA lot of people volley for raw food only (or mostly) but from the way I understand evolution part of the reason humanity developed superior usage of brainpower was the discovery of cooking, allowing your body to consume more calories at once from the food you eat so you don't spend half you day finding your food and chewing it. Cooking and processing can unlock nutrients that wouldn't be accessible to our bodies if we just ate them raw. While a lot of food is great to eat raw, like salads and fruits, I'm not going to eat a raw sweet potato, I won't get anything out of that. Even raw kale is so fibrous you chew each leaf forever before you can swallow it, but if you massage it with some acidic dressing, it softens and becomes significantly more edible.\n\nSo let's say that's our philosophy now, let's find every nutrient in every food and figure out what needs to be cooked and what can be eaten raw, and we'll build a diet out of that, right? Wrong. There's no database for that... except history. This is another thing I think Pollan conveys very well in his book (and Netflix series) cooked. People have thrived for thousands of years without obesity, but also without juicing, or vitamin supplements, or dieting smoothies. Learning from cultural traditions of eating is the best way I've been able to understand what is healthy. There are just too many variables! Even if we know the exact contents of everything we put in our bodies, we won't know how much of it we actually digest and benefit from unless we can describe every enzyme and interactive nutritional agent in our body, which won't happen for a while. My favorite example is corn, or maize more specifically. Early civilizations of North and Central America lived off of corn, it made up a huge percentage of their diet. When corn was taken back to Europe, everyone ate a bunch of it and got sick with pallegra due to a vitamin deficiency or something (one of the big diseases contributing to the spread of vampire lore, but that's for another time), which was not fun. Turns out, maize had some pretty specific processing protocol (the Good Eats episode on tortillas explains this very well) to extract nutrients from it, along with how it interacted with the food in the rest of their diet.\n\nNext there's fermentation. This is food processing, where bacteria basically digests part of your food for you, adding some tasty and sometimes nutritious treats of their own. Chocolate, bread (made properly), beer, wine, yogurt, and sometimes pickling are all forms of fermentation. I don't know a lot about why fermentation is good for you, but there's a reason it's been around about as long as we have. It's a good place to start for healthy food preparation ideas.\n\nTLDR: Learn about food culture and traditions. Cooking methods, ingredient combinations, and even fermentation techniques developed over generations of thriving and healthy lifestyles. Use them. Also nutrients on a label can only tell you so much, assuming we know everything about how the human body processes food is ignorant. Michael Pollan, Good Eats. Great references for me.",
"Part of the problem is that science journalism has conflated \"a single study came out that says X\" with \"all scientists now believe X\" and created that impression in the public. So with that in mind, it's easy to see how it could appear as if \"scientists\" are constantly changing their minds if you consider \"scientists\" as a monolithic unit. \n\nIn my opinion, this has also eroded the boundary between fact and opinion in the public imagination. These articles try to tell us \"all scientists now believe X\", implying that \"all scientists say X is fact\". Really the takeaway should be \"there is some evidence for X, but it could also be Y, **we don't know yet**\". But uncertainty isn't flashy.",
"The main reason is the rather obvious one that properly conducted studies take a lot of time, planning and money. To get funding it is desirable to explain why you are not simply replicating previous studies that have been done in an area. Therefore it is very unusual to be comparing identical studies.\nAnother reason is that some areas such as diet and nutrition have a lot of preconceived notions that suit certain ideas such as weight loss is not about energy intake versus expenditure. So studies that support the basic physics are not news whereas poorly designed and controlled studies with a headline of \"Scientists say calories don't matter, eat what you like\" is going to attract a lot of attention as it suits what many people want to hear.",
"In my experience talking with scientists (emphasis on endurance sport performance) they don't see a lot of conflict or contradiction, but rather a gradual increase understanding the whole picture. They have the experience to know that the results of a study are necessarily limited in application and focus.\n\nThe popular press on the other hand is another matter. While a scientists will be the first to say that Study X reveals something they will qualify this noting that the results are constrained to certain duration of exercise, experience and fitness of subjects and a variety of factors. The popular press is frequently guilty of extrapolating a positive sign from research into a much larger population case than the research supports. There are some genuine areas where new research contradicts and corrects old assumptions but most research simply widens the arc of understanding. The results seem in conflict when they are poorly reported in the media.",
"Actually we do know the basic stuff about fitness nutrition. For example we definitely know that to lose weight you need to eat less calories than what you maintain and to minimize muscle loss and maximize health along the way you just need to consume enough protein and the essential micronutrients/fats needed for life.\n\nThere isn't a secret diet or food that will make you lose fat and there isn't a single food item/family that will 100% make you fat (carbs for example as many people think). It's all about the total calories.\n\nHaving said that, fitness is a big industry that thrives on the ignorance of the general public to sell them fad diets and supplements to lose fat and gain muscle. If the general public knew how simple it is to build muscle and lose fat then they wouldn't buy said fitness industry products."
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zmrey | Can a star be far enough away from Earth that it's light never reaches us? | The speed of light, when passed through a medium like water, can stop completely over a distance of a kilometer. If space is not really a vacuum, instead being made out of an extremely low-density medium, how far away does a star have to be, so it's light does not reach earth? | askscience | http://www.reddit.com/r/askscience/comments/zmrey/can_a_star_be_far_enough_away_from_earth_that_its/ | {
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"Yes! However not for the reason you're describing. Space isn't an extremely low-density medium (like the [aether](_URL_1_)) - it's a near-vacuum with very few particles, true - according to [this](_URL_0_) it's 10-100 atoms/cubic meter. \n\nSpace is expanding. There are galaxies on the other side of our visual horizon (or outside of our observable universe), because space is expanding there is a point where we won't see them anymore.\n\nLight travels at a given speed, space expands at a given rate. By balancing those two factors it's possible to figure out how far the furthest away thing we'll ever be able to see is. \n\n~~Basically, we won't be able to see anything further from us than the distance in which space expands at a rate larger than 1 light-year per year.~~ See below this."
]
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"http://www.wisegeek.com/what-is-the-intergalactic-medium.htm",
"http://en.wikipedia.org/wiki/Aether_(classical_element\\)"
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2zy1de | Why are the biggest animals almost never predators? | Throughout the history of the world, the largest species have usually eaten plants or very small animals such as plankton. Why aren't the largest animals always predators? | askscience | http://www.reddit.com/r/askscience/comments/2zy1de/why_are_the_biggest_animals_almost_never_predators/ | {
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"Larger animals require more food to sustain their body mass. For example, a leopard is estimated to need to eat 100 lb's of meat to gain one pound of body mass. You can also see that size and all of that would potentially slow an animal like an elephant or hippo (who also have a very large bone structure) because of their weight and general slowness due to the momentum they would generate at high speeds and the stress on their bodies. They need more food to sustain their big sizes. \n\nDinosaurs are an example of a large environment full of large prey and predator but life never quite evolved that way again. \n\nHope you understand ",
"Surface area to volume ratios are important whenever you think about an animal's body size. With increasing total size, surface area increases at a slower rate than volume does ( length^2 vs length^3 ). Surface area leads to heat loss, which is wasted energy. A big animal requires fewer nutrients per unit body mass to stay alive, so for herbivores that consume nutrient poor (relative to meat) vegetation, there is an advantage to being big.",
"Great Question\n\nI think the best answer to your question was provided by Max Kleiber, a Swiss biologist who published a paper in 1932 that describes the relationship you eluded to in your question. Kleiber found that an interesting relationship existed between the size of a predator and the size of their prey, which is now referred to as Kleiber's Law^1. An expansion upon his theory suggests that larger organisms need to eat less food per lb than their smaller counterparts. One of the most contributing factors to this is the rate of heat loss they experience. Larger animals lose heat at a much slower rate than smaller ones.^2 \n\nIf you have further interest in this topic I recommend reading up on Allometry.\n\nCited:\n1.Max Kleiber (1932). \"Body size and metabolism\". Hilgardia 6: 315–351.\n2._URL_0_\n\n"
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3skqed | why were/are cars designed to slowly roll forward when no pedals are pressed? | I read about *why* this used to happen with older cars, but surely they or newer ones could be designed to not do so.
Is there a reason it's better for the car to move forward slowly with no pedals being pressed? It just seems like a silly precedent. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3skqed/eli5_why_wereare_cars_designed_to_slowly_roll/ | {
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"It's not. The engine is running, and it outputs power. Leave it in neutral (disengage the drive shaft) if you do not want to propel the car forward/backwards. If drive shaft is engaged, the very act of having the engine on will produce a minimum amount of power in whatever gear you have it in. "
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169fdh | What are some of the most plausible verifications of ancient Oral history? | I have read a few books claiming that various aboriginal people's have exceedingly old oral histories verified by physical sciences.
Is this more fringe-science nonsense or are you, the historians of Reddit, aware of a situation where the ancient oral history of people has turned out to be remarkably plausible?
For example, the Iroquois, the Australian Aboriginals and various African tribes are all often said to have extremely accurate oral traditions, have any parts of them been validated by physical science or corroboration by other verifiable historical records? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/169fdh/what_are_some_of_the_most_plausible_verifications/ | {
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"Some examples:\n\nThe Iliad is, or was, oral history, but it had a lot of correct information about the world of that period (there was in fact an important place called Mycenae, there was a city just where Troy should be, the whole shebang did fall apart right about when it was supposed to, and so on). \n\nThe Lemba people of South Africa had an oral tradition that they were the descendents of Jews; people dismissed this (arguing, i think, that they had picked up Bible stories recently). Turns out that they DNA testing says that this is very plausible.\n\nI'm not sure what you mean by \"verified by physical sciences,\" though.\n\n",
"There are a lot of examples of oral history accurately describing volcanic eruptions. I cant remember the book where I read about some groups on the Pacific Northwest, but I did find this interesting article online: \n\n_URL_0_\n\nIf you have access to JSTOR or another history database you can find a lot of articles on this. Well, some articles on this. I found [\"Northern Athapaskan Oral Traditions and the White River Volcano,\" D. Wayne Moodie, A. J. W. Catchpole and Kerry Abel, *Ethnohistory*, Vol. 39, No. 2 (Spring, 1992), pp. 148-171 ](_URL_1_) THat's a link to JSTOR though.\n\nHere's the abstract: \nThis article presents Athapaskan oral traditions that tell of volcanic eruptions at the beginning of time. It concludes that these stories recall a volcanic eruption in the upper White River basin of Alaska circa A.D. 720. It also suggests that the ash fall from this eruption, which covered most of the southwestern Yukon Territory, triggered population displacements that led to Athapaskan migrations eastward into the Mackenzie Valley.\n\nSo yes there are oral histories which have been \"validated\" by geologists/scientists/whathaveyou.",
"The [Homeric Question](_URL_0_) is the one I'm most familiar with.\n\nIt has been largely proven that things like Homer's Iliad and Odyssey were indeed passed down orally for generations without being written down. Milman Parry and Albert Lord went to Yugoslavia and extensively studied the oral traditions there of singers/poets that worked from memory. By working from certain repetitive formulas, the singers are able to recall extensive tales. There are videos of this available [here](_URL_1_).\n\nAs for historical accuracy, the city of Troy did indeed exist. The site was initially excavated by Heinrich Schliemann, although later work has identified a different stratification layer as a more likely candidate for \"Homer's\" Troy. But in terms of the Iliad as an even semi-accurate retelling of a battle that occurred in an archaeologically identifiable fashion - probably not. The Iliad is far more useful in understanding things like Greek Bronze Age ideas about honor, distribution of plunder, etc."
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c9uwc5 | why can firms like ally & goldman sachs offer much higher interest rates for savings then my own bank? | They have rates of \~2.15% while my own bank only has 0.01% interest on savings. Why is this?
Edit - follow up question, besides more inperson support and physical branches, why would anyone want to keep savings invested in the banks with such lower rates, especially now in the digital age where transfer ease/time is neglible? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/c9uwc5/eli5_why_can_firms_like_ally_goldman_sachs_offer/ | {
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" Instead of higher interest rates, it offers services like in person tellers, physical branches, linked checking accounts, notary services, certified checking and networks of no-fee atms. Enough people value those extra benefits that those banks don't feel the need to offer higher interest rates to compete with online no frills banks.",
"Limited (in GS case) or no (ally) local branches allows them to reduce their overhead of paying for locations, utilities, cleaning, staff, etc. So they offer more competitive rates to attract customers because they have fewer expenditures so they can funnel some of that extra money into returns.",
"Banks make most of their money from issuing loans. \n\nThey're allowed to lend more than they have in cash, but they need to have at least some money to start with, so they offer savings accounts to get people to give them money to lend out. \n\nThen the Federal Reserve sets a requirement for the percentage of deposits that they have to hold in cash or at the Federal Reserve. \n\nThe idea is that they incentivize you to give them your money to hold by giving you some of the interest they earn by lending your money out. But a lot of the largest banks have way more deposits than they need to meet the Federal Reserve requirements. So they don't have to pay any interest because they don't need your money anymore."
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8y1gw9 | if clouds are masses of condensed water, then how come if a plane flies through it, the plane does not get wet? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8y1gw9/eli5_if_clouds_are_masses_of_condensed_water_then/ | {
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"Why do you assume they don't get wet?\n\nThere will be some water on the plane but not a large amount. Compare to what happen if you drive a car trough mist/fog that is like a cloud at ground level. It is not a huge amount of water that stick on the car. A plane is faster so it passes trough more clouds/mist per unit of time but the force of the wind is also higher so it will blow away the water.",
"It does get a bit wet, just as your car gets wet when you drive fast through a lot of thick fog. Sometimes you can even see the moisture streaming along the plane's windows.",
"Planes do get wet when they fly through clouds. How wet depends on the type and density of the cloud. ",
"If the plane is warmer than the surrounding air, it would resist (or counteract) the tendency of water to condense on it. Just like a cold drink can collect condensation in a room where there isn't (normally) any water condensing, the conditions of the *surface* impact this as much as the conditions of the air do.\n\nAlso, planes fly very fast. If water did start forming drops on it, it would likely get blown off. So water may come in contact with the plane, but never stay still for long enough or form big enough drops for it to be visible. \n\nLastly, planes can get wet and this is an especially big issue when the water *freezes* and ice starts to build up. They have heaters on the outside to deal with this, and procedures/backup devices to handle a situation where stuff stops working as a result of ice. But occasionally when the situation isn't handled right, ice can cause plane crashes. There was a big crash a few years ago (an Air France plane IIRC) which happened because a speed sensor was blocked by ice. The pilots did not correctly realize that its reading was wrong, or switch to other methods to read or guess their speed. It *may have been* a preventable crash if they pilots had been more aware or trained better in that case, but in those circumstances the result was deadly. "
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3i1n64 | why is it racist/closed-minded to find people of a race unattractive? | I got called out today because a couple of Black women overheard a conversation I was having with my White mom; I'm Mixed. I had said that I don't really find myself attracted to Black women, but White and Asian women, and one of the two had called me out quite loudly, shouting about how I was this horrible, racist, blah blah blah.
I don't get how I'm racist if I don't find myself attracted to Black women.
EDIT: posted this further down but here:
Context: We were at a informal pizza parlor kind of restaurant and we were not speaking that loudly, but one of them kept looking over at us. Eventually my mom asked me if I was looking to see anyone and the conversation went like:
"meh I dunno. I'm going abroad in a year for a year and I'm looking for something long term and someone with whom I could go abroad. [insert somewhat closed-minded country of interest of study here] is a nice place, but if I were to see someone, I'd enjoy it so much more if we could go together."
"What about [Black girl I dated on and off]? You two still a thing?"
"Nah, and I think it's good because I don't know how she'd react to [country of interest] culture. I mean id be hard-pressed to find a Black woman who'd be
"That's true, well do you have your sights set on anyone?"
"this one girl from [country] and I have actually been talking this summer and we're getting coffee once we're back on campus. She might be going abroad."
Eventually it circles around to me saying "Well maybe it's a good thing I don't find myself attracted to Black women—otherwise I might be going all alone."
They were eavesdropping on the entire fucking conversation, it's not like I was like "lol Black wimmenz are 2ugly6me."
| explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3i1n64/eli5_why_is_it_racistclosedminded_to_find_people/ | {
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"It's not. Some people are overly sensitive and think too highly of their own opinion. If you're not attracted to black women, that's completely fine as long as it doesn't lead you to treat black women poorly.",
"You aren't racist. You were expressing an opinion of what you prefer.\n\nIf I were to say I prefer shorter women, \ndoes that automatically imply\ntall women are not attractive?\n\nYou weren't being racist, they were being hyper sensitive.\n \n ",
"They weren't mad about your preferences, they were mad that you were talking about them in public. How would you feel if you were sitting in a restaurant, and someone at the next table over was talking about how ugly mixed-race people are?",
"There are people who like feet over boobies, it's fair to say that some people like Hispanics over blacks or whatever example you wanna use. You can't really change who you wanna get dicked by or dick down. ",
"If you happen to not be attracted to certain features, and those features tend to be present in black women, then you're not racist.\n\nIf you're not attracted to certain features *because* they tend to be present in black women, that's racist. Problem is, it's not always clear to a third party like the two black women who overheard you which of the two it is.",
"Among the black community there is and has been a huge lack of support for black women particularly from black men. While having preference isn't a bad thing and very normal you might have struck a nerve. It's quite possible these women have gone through harsher treatment from other men of color and were lashing out because of it. \n",
"Aesthetic preference isn't completely 100% unambiguously something that you're born with. Stupid people extrapolate this to mean that if they aren't in your aesthetic preference, it's because you're racist. Racism is the only reason you couldn't possible find them attractive in their deluded mind.\n\nSo no, it's not racist. You just met a complete idiot.",
"Short answer: Societal rules(constructs) and human psychology don't mesh well.\n\nDisclaimer: I am on painkillers from surgery two days ago. This may be a bit disjointed, but once you look at the larger concepts, it is all relative. Here in I shall talk about not just \"racism\" but all sorts of preferences and such in general, because it is all manifestations of the same simple(when you get down to it) evolutionary mechanisms.\n\nWe say racism is bad, but we have an instinctual urge to be more trusting and attracted to that which is similar to us. We tend to distrust that which is dissimilar or unfamiliar. We often bond in the face of adversity, and when there is no obvious adversity to be had, we can sort of force something into that wedge. We don't do this on purpose, we do this for the same reason dogs piss on car tires.\n\nBut we create a social construct about how that is unfair, and how we're above nature, almost like religious worship. We have fabricated an impossible golden standard based on wishful thinking and pixie farts.\n\nOne of the best ways to get over \"racism\" is to be conditioned to being around a wide variety of other races as we are growing up. We can't simply *will* our instincts to react a certain way.\n\nI put \"racism\" in quotes because that is only one manifestation of what I talked about, distrust of that which is different. We tend to be distrustful and not attracted to people who look \"gross\", retarded, ill, dangerous, creepy. We don't want them around us and we don't want to breed with them. We often actually treat people who would want to breed with a mentally challenged person, or the very young or very old, or the non-human... as if they are criminal should they try such a thing.....\n\nIt is all about how we've evolved to bond. Over time, those shortcuts became prevalent features in our subconscious because they were useful. We don't find circus freaks and mentally retarded people attractive(mostly), because that would, in general, lead to a weakening of the gene pool....our best chances of reproduction producing viable offspring is someone who is obviously healthy and likely to get along with us. \n\nJudging by a surface trait like skin color isn't really an active choice at all, it is a remnant of evolution that society declairs is \"unfair\". Science is hardly ever fair when it comes to societal standards.\n\nYeah, I went there. There is biological reason to be \"racist\", and in fact, that is the natural state if society doesn't domesticate us. Human's **are** just animals after all, so saying \"domesticate\" is quite apt.\n\nThat we're on the top of the psychological chain and can think about things on a higher order does not eradicate those natural tendencies. We're all judgemental beings, we take cursory looks at X and decide whether we like it or not before we ever try it. People, food, what movies to watch, everything. \n\nIt is *all* a manifestation of the same mechanics within our psyche/brains. Racism is but one sequelae of the illness that is being human.\n\nAnd that is the problem with social constructs. They are fabricated things that are established based on one of our more flawed and subjective measures, emotion. It is no better than dining etiquette or thinking that \"cursing\" is \"bad\". Which are just more tools we use to judge or feel superior to others.\n\nIn fact, that in and of itself, is what I find a bit Ironic or Meta. You get an ignorant racist, who, because of the way evolution has panned out and his separation from society, has a thing against Purple people.....and we see just that....and judge him as a bad person off the get go. We don't take time to study why he feels that way, we just assume that he is a lesser being.\n\nYou see that in a lot of activist types, a kind of hypocrisy and/or projection(seeing the flaw in yourself and subconsciously projecting it on others). There are even people in this thread who are doing such a thing, taking a very tiny and meaningless bit of information and forming opinions about you, some of them severe.\n\nWe like what we like. We can't really control it. I like pizza, but not with anchovies. I like icecream but not yogurt.\n\nIs that fair to yogurt or anchovies? No.\n\nCan wishful thinking, or an arbitrary decree from others, change my tastes/preferences? No.\n\nCan a bit of conditioning be employed to over-ride that natural state of aversion? Sometimes.\n\nAnd that is the best we can do. People can't just up and decide to be straight or gay. Surely society influences us in that area, as well as our instincts and subjective tastes so we're not entirely \"born that way\". Saying \"born that way\" is an intellectually lazy version of saying \"we really can't control our own preferences\" While can choose to try to *do* anything, we cannot simply choose to *be* something else.\n\nGetting along in society is a two way street, IF that is what we want. We have to admit that none of us are perfect. We have to admit that human's are not biblical creatures designed to be X, Y, or Z. We evolved here like everything else. Evolution is not perfect. We all have many flaws. If we want to be forgiven for our flaws, we have to be willing to overlook flaws in others.\n\nMe, some skin color doesn't strike my fancy. I am not a fan of extremely dark skin, aesthetically speaking. I really like pale skin, and I can get into bronze skin or even very dark skin if the features are otherwise attractive to other tastes that I have. The eyes just so, a nose that isn't too gnarly, long legs, etc...whatever your anatomical kinks are. (Whether you like pepperoni or not, maybe You do like anchovies, but not green olives....)\n\nMost people are the same as that. Many people, though, will avoid making a long rambling post like like I am doing here and just say something with a few words. \"I am not a big fan of black chicks.\" That is not an inherently evil statement. It is an offhanded and shallow statement, yeah.\n\nBut why should people have to curb their wording....It's going to be tough to coddle the rest of the entire planet. If we all refrained from being offensive to anyone, our vocabulary would be quite limited. Even monosyllabic grunts some people **take** offense at.\n\nThe ultimate end to being that kind of authoritarian social structure, is to put everyone in place of total solitude so they cannot interact with people at all, because someone *will* get pissed with enough time and exposure.\n\nAs I was saying earlier, the best we can do is try to overlook faults in others. Authoritarianism isn't the way to go, because everyone's criteria for \"authority\" is pretty much themselves and those they agree with, fuck everyone else, because, reasons. We have evolved to be tribalistic. This is why we riot over sports games, this is why we argue on the internet, this is why people who like Coke think they're better than people who like Pepsi...etc\n\nAs much as I talked about evolution it's pretty clear I'm not religious at all, even been the outspoken atheist a time or three, but that doesn't mean that some of them didn't have some good mottos to live by. Turn the other cheek....do unto others. If society could not throw out the baby with the bathwater, we might be able to survive long enough to get off this planet.\n\nWith all that, I'll step down off my soap-box and try to remember to thank my Dr. for prescribing Vicodin after my nose job(functional, not aesthetic, it is going to be as ugly as it always was)\n",
"It isn't racist *to do that*. But, finding an otherwise attractive person ugly due to her ethnic makeup probably comes from living in a society that conditions you not to like her ethnicity, if you follow. You are not *being a racist*, but you, like all of us, are conditioned by a racist society.\n\n .\n .\n .\nI mean, think about it: you are (as an example) a heterosexual male. You see a beautiful, stacked, nude woman. Iman, say, or Beyonce, or Gabrielle Union, whoever. How could it be normal or natural for you to not think she was attractive? Is skin tone *really* stronger than, you know, your natural heterosexual drive? I don't think so.\n\n .\n .\n .",
"This is a loaded (it's not obviously true you are racist if you feel that way) and subjective question so this has been removed.\n\nIt also appears like you posted this in order to argue a point of view, please see the sidebar:\n\n > Don't post just to express an opinion or argue a point of view.\n\nIf you want opinions from redditors try /r/askreddit. If you want to be convinced otherwise try /r/changemyview (but read their rules)."
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cbwx0a | why are there different types of zits? i.e. blackheads, different types of puss, seed-esque, etc. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cbwx0a/eli5_why_are_there_different_types_of_zits_ie/ | {
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"Blackheads is just pores thst fill with dead skin, dust etc and culminates into a black thing.\nZits are basically where the skin has been ruptured, andd bacteria have been allowed to enter pass most of the dermal layers. Blood clots over hole, skins heals over yadda yadda, but bacteris is still inside, so white blood cells are deployed in a video game like scenerio to kill bacteria, begin long ass war. The white residue left under skin, is primarily dead white blood cells, bacteria etc. The reason why some zits grow so latge, is because some invasive bacteria have extremely high mitotic indices, basically replicate very quickly, and it takes the body a while to either develop or find an antimicrobial cell that can deal with the bacteria. Same with a cold or flu really. \n\nIf pus is different colours, it probs to do with the chemical structures of the bacteria, more rhan anything else. Or more simply, the skin might thinner or thicker causing cllour distortion. Think of the ocean, deeper you go the more the colour arounf you will change.\n\nIdhac wtf seed-esque is so ill leave someone else to answer."
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3clv5r | What did people have for breakfast in the 1920's | particularly rich american city dwellers. it's for a play | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/3clv5r/what_did_people_have_for_breakfast_in_the_1920s/ | {
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"They were similar to continental breakfasts, with coffee and bread. Oatmeal was still pretty big in the north, while grits were the thing in the south. Orange juice was pretty commercialized at the time, so a wealthy family would have likely had orange juice. Bacon and Eggs were also a pretty normal meal at the time for breakfast, so they might have had that as well. Dry cereal also started to be more commercialized. Breakfast hasn't really changed too much since the 1920's. There's some mention of breakfast here (_URL_0_), but it focuses mostly on a lot of other foods. "
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7mzgui | how do high blood pressure medicines help reduce blood pressure? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7mzgui/eli5_how_do_high_blood_pressure_medicines_help/ | {
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"There are a few different methods to lower hypertension depending on what is causing it. For what is known as \"essential hypertension\" (in where there is no known cause to the high BP), a certain class of BP meds work to lower BP by decreasing the preload of the heart, which means less blood is going in so the pressure is not as high going out because the volume is lower. People with left sided cardiac failure often have problems retaining fluid, so a diuretic (or \"water pill\") can help the kidneys remove more water from the blood to reduce blood volume, which in turn reduces blood pressure. How cool :) ",
"Couple of ways. High blood pressure mostly comes down to the heart pumping harder/faster, blood vessels squeezing harder (blood vessels have a little lining of muscle), and salt/water balance. The body controls all this in a couple of complicated ways.\n\nLet's cover the most common groups:\n\n* Calcium channel blockers (like amlodipine) stop blood vessels from squeezing down as tight by working on that little lining of muscle.\n\n* ACE inhibitors (like lisinopril) stop part of a signal relay that normally tells blood vessels to squeeze down and tells the kidneys to hold on to salt and water. Angiotensin receptor blockers (ARBs, like losartan) are really similar, but work on a different part of that relay.\n\n* Thiazide diuretics (like HCTZ) are interesting. You'll mostly read that they make you pee off salt and water, so you have less blood in your vessels, meaning lower blood pressure. There actually seems to be a lot more to it long-term, but it's not ELI5 (they don't even explain this part well in med school.)\n\n* Beta-blockers (like metoprolol) block signals that tell the heart to beat harder and faster.\n\n* Alpha-blockers (like prazosin) block signals that tell blood vessels to squeeze down. They act on a different part of the same big system as beta-blockers. \n\n* Central alpha agonists (like clonidine) act on the same system as alpha and beta-blockers, but instead of blocking the signal, they trick the brain into not putting it out to begin with.\n\nIn general, what we've realized is that blood pressure isn't always the thing to focus on. Some drugs that decrease blood pressure don't make you live any longer, or have fewer heart attacks and strokes. (Alpha and beta blockers are both great for a lot of other problems, but not great if high blood pressure is the only one. Thiazides, calcium channel blockers, ACE inhibitors and ARBs are all cool.)"
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2q81u7 | What year was it when people started using the current dating system? | Rome wasn't Christian until 326. And the Gregorian calendar wasn't established until the 500s. So what year did people think it was when they switched? Did anyone ever know it was year 1? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2q81u7/what_year_was_it_when_people_started_using_the/ | {
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"In short, many different dating systems were used before the Anno Domini system was adopted. Common systems included a king's regnal years, the consuls of Rome (until the office fell into disuse), or the \"Year of the Martyrs\" dating from the ascension of Diocletian, a significant persecutor of Christians. This chaos probably helped Dionysius's Anno Domini system be adopted.\n\nYou might also be interested in [these previous threads about the calendar](_URL_0_), from the subreddit wiki.",
"There's no one date. Some credit Bede with popularizing the AD system in the West, but Dionysius Exiguus proposed it circa 525.\n\nIf by dating system you mean calendar, again each region was different but the Gregorian calendar was introduced in 1582."
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3r4ls1 | why do conservatives not typical push for conservation of the environment and of natural resources? | This is not just a semantic question. Conservatives favour family, the economy, a strong country and a continuation of the status quo. It would seem that the degradation of the environment and the overuse of resources would be a being threat to these values than, say, terrorism. So why is conservation of the environment and of natural resources not generally a prominent part of the conservative platform? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3r4ls1/eli5_why_do_conservatives_not_typical_push_for/ | {
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"Generally conservatives are against regulation of business, and conservation of the environment requires businesses to be regulated so that they don't exploit it. This is a case where their economic stance of \"making laws that regulate businesses is bad\" outweighs any other considerations.",
"The short economic answer would be that environmental degradation can only be reflected by charging financial costs to those who are causing the degradation (ie. cap and trade). These extra costs are likely viewed as economic inefficiency which tends to be anathema to conservative ideologies ( which favour light-touch (or zero) regulation and simplifying tax, both of which are aimed at minimising inefficiency).\n\nThe truth is that policies like cap and trade actually maximise efficiency by including previously-unvalued environmental degradation in the costs of polluters but most conservatives don't view it this way (although some do).",
"There's a few things that come into conflict,but they all come from the same root belief\n\nThe main one is that if you accept that it's happening,you pretty much have to accept that the only way to fix it is government regulation. (If the market was taking care of it,it wouldn't be happening).most are ideologically very against government regulation.\n\nGenerally this leads to them trying to mesh those two beliefs. Generally this means \"It's not happening\"(or its not happening on a big enough scale to matter),\"other countries will take advantage of it anyway \",\"God will handle it\" etc.\n\nThey have a conclusion (government regulation is bad),and back rationalize to satisfy that belief",
"There's actually a group of \"green\" conservatives who are doing just that. AND!!!! Ecologists often tag-team with hunters to preserve natural spaces because hunting is important to rural conservatives :)"
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4b1kno | is reverse-engineering easy? like if say, someone dropped an f-22/f-35 at the chinese doorstep how much could they learn from it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4b1kno/eli5is_reverseengineering_easy_like_if_say/ | {
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"I wouldn't call it easy, but a government power like China wouldn't be hard press to find the kind of money to get a good team together to solve any problem like that.",
"Well it some areas of engineering it's quite easy. Basic measuring tools can give dimensions for the physical make up of said plane.\n\nthen there are ways of finding out which alloys and polymers are used in the making. It's a little harder than measuring but still not too terribly hard. \n\nThe electronics on the other hand would be pretty inconceivable to clone. Military programming is a big kept secret and unless created by the Chinese would be pretty hard to decipher and replicate. \n\nSo an exact clone would be terribly difficult but a working jet that looks like an f22 not so much.",
"They could learn a lot, but they couldn't make an exact duplicate. They don't have the metallurgy to build an engine that'll match the performance of the real thing's even if they were able to copy the physical design perfectly.",
"It would certainly boost their aviation programs by quite a bit, but it doesn't mean they'd be able to make a copy of those planes. At best they'd be able to glean some working principles and make a poor substitute.\n\nThe plane is just the outcome or artifact of a long and complicated design and manufacturing process. They only see the outcome of the process, not the process itself, but the process is what makes the plane. So for example, they can measure the plane's dimensions, but that doesn't mean they'll be able to replicate the production process that went into making the parts. It's like being able to measure that a sample of gold is 99.99999% pure but that doesn't mean you'll know how to make gold that pure. In this case, they'll be able to do a lot of analysis on things like the stealth coating and stuff, but they'd still need to figure out how to make them that way.\n\nYou can read about Russia [reverse engineering the B-29 bomber](_URL_0_). They had issues such as the U.S. using the imperial system, so things like sheet aluminum thicknesses were in inches, while Russia (like everyone else) had moved onto the metric system. So it was a pain to actually make a copy, even though they had the measurements, since the available materials were not calibrated to the same scales (i.e. imperial vs metric). And this was back when production processes were relatively simple, and a plane's performance was largely mechanically based (as opposed to nowadays, where there's computers for everything). Nowadays the production process for most parts of a military plane is awesomely complex, and thus both difficult to figure out by just looking at the end result (the plane), and very expensive to reproduce (custom manufacturing processes, large jigs, etc.).\n\nAs a side note, apparently one of the reasons why the F-22 is unavailable for export is because if a foreign nation got it, they could easily get its source code and be able to figure out how the U.S. operates its AESA radar, flight controls, etc. The F-35, on the other hand, was designed from the ground up for export, and so its software is heavily encrypted; other countries can use it of course, but it's supposed to be very difficult to reverse engineer (decompile, etc.). Additionally, one of the problems with restarting F-22 production is that its processors are already out of date now and no longer manufactured, although they were undoubtedly top-of-the-line when the plane was designed. So even for the U.S. to make more (and the U.S. of course already has all the blueprints etc.) would be a difficult proposition. It would be orders of magnitude harder for any other nation (who does not have the blueprints) to make a copy.\n\nBut having the plane would undoubtedly boost their aviation programs by quite a bit. Not anywhere near being able to make a copy though."
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3wevwx | how is the deep web inaccessible via search engines? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3wevwx/eli5_how_is_the_deep_web_inaccessible_via_search/ | {
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"Search engines aren't magic. If a site requires a login to access some content, then a search engine won't be able to access it and therefore can't index it. It's the same reason google maps doesn't have pictures of the inside of your hose - they don't have access.",
"If I create a page, but don't link anything to it, or only link to it from inaccessible locations, then it's part of what's called the deep web.\n\nEven if it's accessible you can always use [robots.txt](_URL_0_) to flag it as \"not to be indexed\".",
"Several ways:\n\n1) Content that needs to be logged into with specific info (e.g. your bank account.) Search bots cannot access this.\n\n2) You can tell bots not to index your site's page(s) by implementing the meta robots tag on your site's page(s): Specifically < META NAME=\"ROBOTS\" CONTENT=\"NOINDEX, NOFOLLOW\" > \n\n3) Likewise, you can also tell bots not to index certain pages / directories in the robots.txt file.\n\n4) As others have mentioned, content that is not linked from elsewhere will not get found by search bots and indexed...but even so, if I link to my personal bank account profile and a bot crawls that link, it will still need to log into my account to access it (#1) which it won't be able to do.\n\nEDIT: mentioned .htaccess file when I should have mentioned robots.txt file."
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1f4q86 | Before WW1, did other countries and civilizations have something comparable to the Tomb of the Unknown Soldier? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1f4q86/before_ww1_did_other_countries_and_civilizations/ | {
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"For most of human history war memorials were erected to commemorate great victories. Remembering the dead was a secondary concern. Indeed in Napoleon's day the dead were shoveled into mass, unmarked graves. The Arc de Triomphe in Paris or Nelson's Column in London contain no names of those killed. By the end of the nineteenth century it was common for regiments in the British Army to erect monuments to their comrades who had died in small Imperial Wars and these memorials would list their names. The Franco-Prussian War of 1870-1871 was the first war in Europe in which rank-and-file soldiers were commemorated in war memorials. Every soldier was granted a permanent resting-place as part of the terms of the Treaty of Frankfurt (1871). By the early twentieth century some towns and cities in the United Kingdom raised the funds to commemorate the men from their communities who had fought and died in the Second Anglo-Boer War. However it was after the great losses of the First World War that commemoration took center stage and most communities erected a war memorial listing those men and women who had gone to war and not returned."
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16op89 | What contribution did the British make to victory in the peninsular war 1808 - 1814? | As a scot who was brought up on the Sharpe books and TV series I had always thought that the British had a major influence on the outcome of the campaign, however, my Spanish girlfriend didn't even know the British had fought in this war. What she was taught was that the guerillas made the country impossible to occupy. Who is right?
| AskHistorians | http://www.reddit.com/r/AskHistorians/comments/16op89/what_contribution_did_the_british_make_to_victory/ | {
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"Much like the militia in the American Revolution, the guerrillas were useful in denying the French control or true possession of the country side. However, they fared pretty poorly when forced into a conventional battle against French regulars, and were incapable of effectively besieging and taking French-held forts and cities. Most of the major battles in the Peninsular War were fought and won by British and Portuguese regulars.",
"I think you're both right. Certainly, what we, coming from an Anglo-centric background, consider the important battles (Talavera, Salamanca, Vitoria) were Wellington's victories. This is important to emphasize, as Wellington was the supreme commander of allied forces in the Peninsula from 1812. \n\nHowever, he was undoubtedly aided by the fact that the French could never muster their full strength against him, tied down as they were by harassment from the Guerillas. \n\nWe'd be getting into counterfactual arguments if we were to argue \"Would Wellington have won had the Spanish Guerillas not been so active against the French?\" or \"Would France have abandoned Spain if it became to hard to occupy?\" But let it suffice to say that both Spanish and British played a mutual role in ousting the French from the Iberian Peninsula.",
"She didn't even know the British had fought? Seriously? The contribution was major, but Sharpe is obviously an exaggeration.\n\nFirst, it should be noted that the Spanish were fighting against the British moments before the war, and there was some rivalries between the two. The war started all of sudden, with Napoleon having his troops on the Peninsula and the king abdicating on Napoleon. Brutal repression ignited the spark that was needed: the army (which was quite large, ~100.000-150.000 depending on the source). On that Napoleon ruled Europe and his army was, for the most part, undefeated. In fact, one would think that all was lost until [Bailén](_URL_2_). This was the first time the French Army was defeated since the Empire. The numbers weren't that big (~20-30k forces), but it was an important symbol: the french could be defeated, even with militia (although a large part of the Spanish side was by regulars, but about that later).\n\nThe British offered to help Portugal, which was defended more or less easily, since the French couldn't cope with Spain and Portugal. Although the tale of Bailén spread quickly, the French had a lot to say. Following Bailén, there was a series of small campaigns that didn't end well for Spain. Napoleon gave Spain a huge reinforcement wave, with a large part of it composed by veterans.\n\nBy 1809, Napoleon had the Nort-East part of Spain controlled, but now it faced 3 fronts: Andalusia, (South), Valencia(East) and. The British has sent John Moore, but he was defeated with his army at [La Corunna](_URL_0_), where he was trying to retreat. [Napoleon](_URL_3_) himself was on the Peninsula and it showed. But another miracle happened, on [Talavera](_URL_6_), where a combined force of Spanish and British troops gave a huge blow to Napoleon. Cuesta and Wellington commanded this battle, both great generals.\n\nMeanwhile, the Spanish government was re-created on [Cadiz](_URL_4_) (the very south of Spain), which ended up being in a long siege. This ended up with 1810 being a stale years: neither side had much resources, and Spain harsh terrain punished both armies.\n\nThe british send more weapons and uniforms, which ended up in the Spanish army reformation. But more importantly, on 1812 Wellington took the lead, and with his British-Portuguese army, he took Salamanca (West) and allowed the Spanish army at the south to push. With Napoleon busy in Russia, the large army of Spain had a lot of problems (and so had the Grand Armée in Russia too). From this point, the battles followed until 1814, where the war ended.\n\nNow, about the guerrillas. Bluntly, they were \"romanticized as fuck\" in Spain. [Spain](_URL_1_) is indeed a map full of mountains, hills, heath in the summer and cold in the winter. Not only that, but it's full of small little [towns](_URL_5_). This means that small french governors had a lot of problems, since they couldn't protect themselves from the citizens with the army. As expected, more repression followed, which ended up with uprisings. In some cases, some guerrilleros (people, like you and me, that were tired of french killing either their food or family) would organize and attack with other villages. For the most part, they weren't organized until the late period of the war. At that point, many formed up light militia regiments and followed the regular army.\n\n**TL;DR:** British army helped a lot and Guerrillas helped a lot, and the Spanish army was the main force. Spanish would have won without British in the end (probably), but they still played a massive role (the war would have been much longer, and without pressure on the Peninsula, Napoleon could have been much more aggressive with Europe).\n\nBTW, I haven't sourced this because it's very general and you can find this on most books of the period.",
"The Spanish government held onto the mainland by a toehold in the port city of Cadiz. Without British financial and military aid that city could not have stood. The Royal Navy kept the Mediterranean under control and brought in vital supplies. Moreover a large British garrison and British civil representatives were present in Cadiz. Most crucially, however, the British supported the Spanish with financial aid and military supplies (as they did with all other powers who fought against the French. The nearby British stronghold of Gibraltar acted as a key staging ground for all of this. \n\nFrom my own work on this (my undergraduate dissertation was on Castlereagh’s tenure at the War ministry from 1807-9 and I have done and am still doing a great deal on both Britain and France in this period) I would say that the main contribution was not that of the Spanish government but of the Spanish people. \n\nRemember the Spanish empire was in the process of collapse in this period – its New World colonies were either rebelling or in a state of flux, certainly not able to provide resources for it to fight a war – indeed many of its resources were devoted to unsuccessful attempts at retaining its South and Central American territory. In the peninsula war Napoleon had a difficult time because whilst he (or his marshals) were able to defeat regular armies sent against them or at least deny them progress; they had to disperse the general French strength in the country to fight partisans; guard supply lines; garrison towns etc. – the French occupation was pretty brutal and vicious attempts to put it down only worsened the situation. The British, whilst constantly being pushed back, kept the pressure up and were able to fund the efforts of others such as the Russians and Austrians in other theatres (remember they were fighting the French too!)\n\nThe key element of the British contribution in the Napoleonic Wars that is often overlooked was financial (and easily forgotten in national memories – including Britain – because we find finance and economics less interesting than we do battles). The British state experienced dramatic growth in its revenues during the Revolutionary/Napoleonic Wars unparalleled since the ‘Financial Revolution’ and its growth into a fiscal-military state a century or so before. \n\nGreat Britain bankrolled pretty much every other country involved in the struggle against Napoleon because they were the only country undamaged by the wars; had a huge colonial empire; and dominated international trade and finance. They were subsidizing the efforts of the other powers to the tune of between £10 and £15 million annually in decade 1805-15. \n\nI can give a breakdown of total government expenditure:\n£82 million in in 1811 rising to £113 million by 1815; the budget for 1815 broke down as:\n£18.6 million on the navy; £39.1 million for the army; £15 million for foreign subsidies; and £30 million servicing the now massive public debt. It achieved these figures with a mixture of international trade, borrowing, taxation. The point is that no other state approached this level of funding. My source for this is the work of Professor O’Brien in *‘Public Finance in the Wars with France 1793-1815’* in Dickinson ed., *‘Britain and the French Revolution.’*\n\nI strongly recommend anyone interested starts with Rory Muir’s *‘Britain and the defeat of Napoleon.’* \n"
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145cui | What specifically makes us, and mammals, warm blooded? How is this heat created within the body? | askscience | http://www.reddit.com/r/askscience/comments/145cui/what_specifically_makes_us_and_mammals_warm/ | {
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"Short answer for a very interesting but complex process:\n\nYour body breaks down glucose into smaller molecules which creates adenosine triphosphate (lookup the Crebs Cycle and oxidative phosphorylation for a mind blowingly awesome process of how this happens) \n\nAdenosine triphosphate (ATP) is a single adenosine molecule with three phosphates stuck to it (Tri-Phosphate) The last phosphate is relatively easy to break off and releases lots of energy when it does so our cells use this chemically stored energy as fuel to perform all their functions. With the release of energy from that reaction comes the release of heat. As our cells perform more work we create more heat. \n\nMammals regulate this heat to keep up operating temperature which is warm enough to keep vital processes and chemical reactions working without being too hot which can denature, or break down, our proteins. Cold blooded animals do not regulate their heat nearly as much and rely on external heat sources for regulation. \n\nInfo about ATP:\n_URL_0_",
"There are several ways the human body produces heat. As MYBALLZAC pointed out, the basic metabolism/turnover of [ATP](_URL_6_) (the basic energy currency inside out body) produces some heat. The amount of heat is basically the same whether its hot or cold outside. Think of it as the baseline heat output. Now one way to increase this is increase metabolic activity in muscle cells, i.e. move your muscles. This is the shivering of your body you experience when you are cold. \n\nBut there is another way the body can produce a lot of heat, which is sort of connected to the ATP production MYBALLZAC mentioned, but then again is different. \n\nWhen your body metabolizes nutrients (sugars and fats) during [cellular respiration](_URL_4_) it goes through a lot of steps. At the end during a step called [oxidative phosphorylation](_URL_2_) you end up with a big proton gradient along the mitochondrial membrane. What this means is there is a large concentration of H^(+)-Ions on one side of the membrane, and a low concentration on the other side. Such a gradient represents a pretty big amount of energy. Think of it like water inside a mountain lake. \n\nNow there are two ways you can get the water downhill. You can either use it to produce usable energy by running it thorugh a hydroelectric plant or you can just let it flow downhill unhindered. The equivalent inside our cells (The mitochondria inside our cells to be precise) to the hydroelectric plant is a special protein called [ATP synthase](_URL_5_), which produces ATP (which can be used for all kinds of things) but little heat. \nBut there is a second kind of protein called [Thermogenin](_URL_0_) which allows for the second option. Here the H^(+)-Ions flow back to the other side of the membrane without creating ATP. Therefore all the energy stored in the proton gradient is released as heat. \n\nNow AFAIK this process only takes place in [brown adipose tissue](_URL_1_), so the body still need to distribute the heat using normal blood circulation.\n\nfurther reading:\n\n _URL_7_\n\n_URL_3_\n\n",
"A cool thing I wanna add that isn't mentioned in the other (very good) top comments is that when metabolic activity occurs, such as cellular respiration, **we could predict the release of heat by the laws of thermodynamics!**\n\nSome nifty numbers here:\n\n* There’s 686kcal (686,000 calories) in a mole of glucose\n* There's also 7.6kcal (7,600 calories) in a mole of ATP\n\nA molecule of glucose produces 38 ATP molecules, so if we do 7,600 * 38, we get 288.8kcal. Therefore, the complete oxidation of glucose is only about 40% efficient (288÷686).\n\n**So where did the other ~400kcal go? The other 60% goes off as heat.** It’s impossible to convert one form of energy into another without creating heat. This release of heat is predicted by the law of thermodynamics. In other words, approximately 40% of the energy that’s created is used to phosphorylate ADP into ATP.\n\nFurthermore, this reaction explains why the temperature of your body is almost 100°F. If you start to exercise, cellular respiration starts to speed up inside your muscle cells to produce more ATP, so your body starts breaking down sugars at a faster rate, you breathe oxygen at a faster rate and exhale carbon dioxide at a faster rate and give off even more heat at the same time.",
"Warm blooded refers to internal thermoregulation from physiological processes, cold-blooded refers to external thermoregulation as a result of behavior based processes. \n\nNow my answer is more from a neuroscience/temperature regulation standpoint. Your body has a structure called the hypothalamus that is located in the brain. This controls many functions of homeostasis, from food to temperature regulation. Now when specific environmental factors are present and stimulate the body (excessive cold, heat, etc) then it will trigger a cascade through its neuronal projections. Heat triggers parasympathetic outflow that causes relaxation of subdermal blood vessels, relaxation of arector pili muscles in sweat glands increasing sweat production etc. Contrary to this, Cold triggers cause a sympathetic response - shivering, closure of arector pili decreasing sweat release. The balance of this neuronal activity creates the concept known as the hypothalamic set-point.\n\n2 interesting points: \n\n1. When you are sick there are systemic mediators of inflammation released in your bloodstream that causes an increase in the temperature setpoint of your hypothalamus - This is ideal for white blood cell activity and less so for growth of bacteria/other pathogens.\n\n2. 45 degrees celcius is the exact temperature above which pain becomes a noxious stimulus. Below this temperature, while unpleasant, pain is bearable. Why 45 degrees celcius? Because it is at this point that proteins start to denature in our body.\n\nSource: I am a 4th year medical student. I have also taken some information from my neuroscience textbook: _URL_0_\n\n* edited for formatting",
"May I just also add that the term *warm blood* is misleading (the correct term being '[endotherm](_URL_1_)') because cold blooded ([ectotherm](_URL_0_)) creature's blood is not necessarily 'cold' as temperature is relative. ",
"Lots of good responses, but how has no one mentioned the fact that the primary separator between cold and warm blooded animals is the heart. Reptiles and fish have a two chambered heart, humans have a four chambered heart. The difference is that in a two chambered heart some of the de-oxigenated blood and oxigenated blood gets mixed, so the overall system is much less efficient, meaning cold blooded animals can't produce as much energy, meaning not enough to regulate body temperature.\n\nMammals don't have this problem. We have a much more efficient system.\n\nThis is intended to add onto all the other responses, which are quite good, but as far as I could tell completely miss this very obvious fact, which I think puts it quite nicely for the layman.",
"There's more to your question than meets the eye.\nFor starters, not all mammals are warm-blooded for the same reason. Naked mole rats regulate their temperature using behavioural methods. _URL_0_\n\nSecondly, the scientific community doesn't recognize \"warm-blooded\" as a useful term. After all, if a lizard sits in the sun for an hour, its blood could be quite warmer than ours.\n\nThirdly, some reptiles are \"warm-blooded\" in the same way that we are, that is homeothermic endotherms. Birds, like the obvious penguin that runs at about 39 degrees C faced with outside temperatures of -50C, or bees and other flying insects that generate substantial heat from their wings, and leatherback turtles that get to be the size of a Volkswagen beetle and thus are so freaking large that they tend to maintain their body temperature.\n\nThe top answers currently talk about exothermic reactions, but the topic is amazingly interesting and complex if you look into all the different things that happen across species and even within a single species the number of physiological mechanisms that exist to regulate body temperature.",
"The term \"warm-blooded\" is misleading. The two categories are endoderm (us) who can regulate our body temperature, and ectoderms who cannot internally regulate their body temperature and therefore have behaviors that maintain their body temperature in the ideal range. \n\nThe heat comes from things that our body does. We naturally create heat through our bodily functions. Everything we do creates heat. When you're cold, your body will aim to create or conserve heat. Shivering is a way to get your body moving so that it creates heat. Our blood vessels become smaller or larger depending on whether your body wants the heat to stay within you or dissipate into the surrounding area. Sweating helps you lose heat because you lose heat energy when the water (sweat) is changed from water into vapor."
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3ie2rb | why are big guys tough (or at least portrayed so in media)? | In all sorts of action and other movies the protagonist inevitably fights a 7 foot tall, often Russian beast of a man. It seems like being tall always correlates to being essentially immune to punches in movies and TV. What does being big have to do with being so tough? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3ie2rb/eli5_why_are_big_guys_tough_or_at_least_portrayed/ | {
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"The old adage 'the bigger they are the harder they fall' is just a feel good statement. The reality is that the bigger a person is the more power it takes to hurt them and the more power that can deliver. \n\nJust think about professional fights, they all have weight classes. 160lbs people do not fight 200lbs people because they would lose. "
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nrb0k | If you put wing extensions on chickens would they learn to fly consistently for prolonged periods of time? | askscience | http://www.reddit.com/r/askscience/comments/nrb0k/if_you_put_wing_extensions_on_chickens_would_they/ | {
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"Chickens have no reason to fly for extended periods of time. Look at the Pheasant for example. These birds don't migrate and don't need to fly for extended periods. Good luck training a non migratory bird with robo wings how to fly south for the winter.",
"No.\n\nSorry I'm not a scientist but I am the proud owner of a pet rooster.\n\nChickens are not built for flight. They can achieve short flights but it's rather exhausting. Also the chickens center of gravity is too far back, they have a sort of ass first posture when flying. If it wasn't for their long necks their feet would be in front of their head in flight. Lastly you would have to completely replace their wings as the are very inefficient for flight, as they have evolved to serve as make shift armor more than for their flight characteristics. If you pull out a chickens wings you will find they are more scooped shaped compared to flighted birds.",
"I don't think it's a wing area problem as much as it is a power problem.\n\nI'm not sure at this point in the chicken's evolution their chest muscles still have what it takes to power and sustain flight for their weight, regardless of wing area.",
"Everyone else has made great points. Going to add one more mechanistic reason why this won't work:\n\nChicken breast is light meat.\n\nI know this sounds silly, but I think this is the simplest way to explain it. The difference between white and dark meat is in part based on the abundance of energy-producing mitochondria in the muscle cells. Dark meat has a much higher density of mitochondria than light meat. This means that the light meat you eat is from muscles that just don't have the same energy-producing capacity as the dark meat in the birds.\n\nMeanwhile, migratory birds such as ducks have dark meat all through their breast muscles. So the chicken needs more than just bigger wings to be able to fly.",
"Even heavy-bodied chicken breeds have the ability to fly for short distances during a growth phase where they have their long wing feathers and have not yet achieved full body weight. It was during this phase that [my pullets decided to become free range chickens](_URL_0_).",
"Chickens are a member of the order Galliformes - game birds/fowl. Along with turkeys, quail, pheasants, peacocks, monals, guineafowl, grouse, capercallies... around 290 species altogether.\n\nThe vast majority of these birds evolved for life on the ground (some like Chachalacas are more tree-dwelling, but this is an abberation from the norm for this group, and they still only fly short distances), and it's one of the \"oldest\" groups of birds (basal, in biology jargon), they never evolved for long sustained flight. They use flight as an escape mechanism, not a major mode of transportation. \n\nThe wild ancestor of domestic chickens are [Red Junglefowl](_URL_1_), they also spend the vast majority of time on the ground.\n\nIn the case of chickens, it's not that they were selected for \"flightlessness\" (in this case meaning little flight) and had the ability to fly long distances before; as far as I know galliformes NEVER had the ability to fly long distances. Chickens are much closer in many ways to their dinosaur ancestors than most species ([Paleognathae](_URL_0_) are the only species closer).\n\n\nI'll note that my studies are mostly in mammalogy, not ornithology, and I don't know the entire fossil history of the galliformes, but I hope this is a good answer!",
"Chickens have no reason to fly for extended periods of time. Look at the Pheasant for example. These birds don't migrate and don't need to fly for extended periods. Good luck training a non migratory bird with robo wings how to fly south for the winter.",
"No.\n\nSorry I'm not a scientist but I am the proud owner of a pet rooster.\n\nChickens are not built for flight. They can achieve short flights but it's rather exhausting. Also the chickens center of gravity is too far back, they have a sort of ass first posture when flying. If it wasn't for their long necks their feet would be in front of their head in flight. Lastly you would have to completely replace their wings as the are very inefficient for flight, as they have evolved to serve as make shift armor more than for their flight characteristics. If you pull out a chickens wings you will find they are more scooped shaped compared to flighted birds.",
"I don't think it's a wing area problem as much as it is a power problem.\n\nI'm not sure at this point in the chicken's evolution their chest muscles still have what it takes to power and sustain flight for their weight, regardless of wing area.",
"Everyone else has made great points. Going to add one more mechanistic reason why this won't work:\n\nChicken breast is light meat.\n\nI know this sounds silly, but I think this is the simplest way to explain it. The difference between white and dark meat is in part based on the abundance of energy-producing mitochondria in the muscle cells. Dark meat has a much higher density of mitochondria than light meat. This means that the light meat you eat is from muscles that just don't have the same energy-producing capacity as the dark meat in the birds.\n\nMeanwhile, migratory birds such as ducks have dark meat all through their breast muscles. So the chicken needs more than just bigger wings to be able to fly.",
"Even heavy-bodied chicken breeds have the ability to fly for short distances during a growth phase where they have their long wing feathers and have not yet achieved full body weight. It was during this phase that [my pullets decided to become free range chickens](_URL_0_).",
"Chickens are a member of the order Galliformes - game birds/fowl. Along with turkeys, quail, pheasants, peacocks, monals, guineafowl, grouse, capercallies... around 290 species altogether.\n\nThe vast majority of these birds evolved for life on the ground (some like Chachalacas are more tree-dwelling, but this is an abberation from the norm for this group, and they still only fly short distances), and it's one of the \"oldest\" groups of birds (basal, in biology jargon), they never evolved for long sustained flight. They use flight as an escape mechanism, not a major mode of transportation. \n\nThe wild ancestor of domestic chickens are [Red Junglefowl](_URL_1_), they also spend the vast majority of time on the ground.\n\nIn the case of chickens, it's not that they were selected for \"flightlessness\" (in this case meaning little flight) and had the ability to fly long distances before; as far as I know galliformes NEVER had the ability to fly long distances. Chickens are much closer in many ways to their dinosaur ancestors than most species ([Paleognathae](_URL_0_) are the only species closer).\n\n\nI'll note that my studies are mostly in mammalogy, not ornithology, and I don't know the entire fossil history of the galliformes, but I hope this is a good answer!"
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3u9l2g | Is rotation relative? | If I match the velocity of a body in motion, I can declare it to be stationary from my observational perspective. There is no test I can conduct to determine an absolute velocity for it.
Now let's say I match a bodies rotation. If I then eject a rock into space, I only need to count the time passed until it appears in the same location to be sure of the rotational velocity.
This has bothered me for a while as it seems to imply that rotation is absolutely measurable, while velocity is not. My question then is this: Is rotation subject to relativity? If so - How could one justify the rotation of a body to be stationary when it seems there are tests available to quantifiably measure it? | askscience | https://www.reddit.com/r/askscience/comments/3u9l2g/is_rotation_relative/ | {
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" > There is no test I can conduct to determine an absolute velocity for it.\n\nFor motion at constant velocity, yes (and freely-falling motion if you wish to include GR).\n\n > This has bothered me for a while as it seems to imply that rotation is absolutely measurable, while velocity is not.\n\nLet's go back to motion in a straight line for a moment. Motion at **constant velocity** is completely relative, but **accelerated motion** is not. If you're accelerating, there is always an experiment you can do to test that.\n\nNow back to rotational motion. Rotations imply accelerations, since your velocity is aways changing (even if not in magnitude, it must be changing in direction since you're rotating). So we know from the discussion above that accelerated motion is not relative, and we know that rotational motion **is** accelerated motion.\n\nSo you're correct that rotation is absolute.\n\nYou can concoct a reference frame in which the rotating object is completely stationary, but it will necessarily be a *non-inertial* frame.",
"This is a good question, let me give you the boring answer first: No, rotation is absolute. All rotation involves acceleration which is not relative, for instance the centripetal force felt by a ball on a swinging chain accelerates the ball inward towards the center.\n\nNow the fun part, we can ask a poignant question, \"Why is the universe approximately at rest along with us when we are not rotating?\"\n\nThis feeds into Mach's principle which colored a lot of the development of general relativity, \n\n* _URL_0_ \n\nIt brings up the question of what is the nature of inertia and is inertia influenced by the rest of the universe? Honestly this debate is so much fun I'll leave you to read the wiki and discover it for yourself."
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cps5sc | How was military recruitment done in Canada/common wealth during WW2? | How did the process of military recruitment and enlistment go in Canada/common wealth during ww2? Would young men just show up to a recruitment centre, select they branch they wanted to enlist in? Or where there different recruiting centres for different branches? How where their trades selected? Did a recruit list what they wanted to do, test for it etc? How was it determined who became an officer and who an NCM? Just curious how the general process of recruitment and enlistment went? Thanks | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/cps5sc/how_was_military_recruitment_done_in_canadacommon/ | {
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"Hi there,\n\nThere a lot of things to consider in your question above, so I will try and start broadly and go from there! I am not an expert on recruitment but I can walk you through some interesting primary sources that can paint a picture of the life cycle or your typical volunteer. \n\nWhen the war began in 1939, even before Parliament declared war on Nazi Germany on September 10th, the Canadian government immediately mobilized Canadian forces and prepared to receive an influx of new recruits. Mobilization was completed as per Defence Scheme No. 3, the third (and by far the most fleshed-out) plan developed by the Ministry of National Defence during the interwar period to prepare the Canadian armed forces for possible conflicts. In this case, the plan in question dealt with essentially another global and/or imperial conflict: it called for the establishment of a \"mobile force\" capable of both home defence and possible deployment overseas as a expeditionary force. Defence Scheme No. 3 was approved and circulated to the 13 Military Districts across Canada in January 1938; these districts would be responsible for managing recruitment in the event of war. Within each military district, several militia regiments would be marked as recruitment centres and were made responsible for managing the influx of volunteers, conducting the necessary medical examinations and suitability interviews, and ultimately accepting men for service. There were also specific provisions for how the recruitment process was going to be conducted, some of which were outlined in Recruiting Memorandum No. 1 which was circulated to the districts in May 1939. Included in this memorandum was the stipulation that preference would be given to unmarried men, and especially men without four or more children. When mobilization began in September 1939, there was therefore already a framework in place to form an expeditionary force and maintain a sizable contingent for home defence.\n\nThe government of prime minister William Lyon Mackenzie King, keen to avoid another painful conscription crisis as in 1917, was interested in prosecuting a war of \"limited liability\". This strategy emphasized the comparatively \"safer\" services of the air force and the navy as being the more important aspects of the forthcoming war effort; large scale army operations posed too much of a risk to national unity if Canada started to suffer casualties on the same scale as it had during the First World War. Although this strategy was soon proved to be woefully naive -- historian C.P. Stacey opined that the idea of any warfare being \"limited\" was \"essentially a contradiction in terms\" -- it did guide recruitment in the first months of the war. \n\nAs for the kinds of decisions that went into accepting or rejecting volunteers, assigning them to a trade, and whatnot, it is useful to look at the personnel files of soldiers that are available through Library and Archives Canada. I have never tried to access the records of someone that survived the war (there may be some special permissions required IIRC), but the records of those who died during the war are [open to the public](_URL_0_) and many can be found online. Personnel files can be quite extensive, generally much more extensive than those from the First World War, and contain a soldier's medical forms, pay forms, injury history, death certificate, will, and other such documents. The most interesting for you, however, would be the attestation paper that was filled out at the time of recruitment which contains all the personal details of the person enlisting. This was often accompanied by an interview form, where the officer conducting the interview would make some basic (often quite superficial) observations on the interviewee and recommend a trade or indicate whether a person could be a suitable non-commissioned officer (NCO) or commissioned officer. \n\n(1/2)"
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9lsmlu | what caused the deserts across the sahara, middle east, and central asia? | What weather conditions created [this](_URL_0_)? Or did ancient civs have access to nukes? All I've heard for central asia is that the Himalayas block moisture from the Indian Ocean leading to a rainshadow effect.
Edit: I still think this is the result of the Finno-Korean Hyperwar | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9lsmlu/eli5_what_caused_the_deserts_across_the_sahara/ | {
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"“Between 30 and 35 degrees both north and south where Earth's atmosphere is dominated by the subtropical high, an area of high pressure, which suppresses precipitation and cloud formation, and has variable winds mixed with calm winds”\n\nBasically there’s regions where rain is unlikely to form due to global air currents as hot air at the equator rises and then falls beyond this zone\n\n_URL_0_",
"These regions are in a band of latitudes known as the sub-tropics. There is a large circulation of air know as the Hadley cell, in which air rises near the equator and descends in the sub-tropics. When air descends in altitude, the pressure increases and the relative humidity goes down, making the air drier. This also helps explain dry regions of Mexico and Australia. Clouds and rain are very unlikely to form in these regions because of this constant supply of dry air. This also happens over the sub-tropical ocean regions, causing less rain there.\n\nA somewhat similar process happens when air goes up and over a mountain range, which results in lots of rain on the front side and a rain shadow (very little rain) on the back side. ",
"The things about weather patterns are true, but it also should be noted it wasn't always desert. The Sahara used to be jungle, which is how our ancestors were able to move through it to get to the fertile Crescent. However an ice age hit, more water was locked up in polar ice, and so areas that were vulnerable to desertification did so\n\nEdit: thanks to all of you for finding a source. I really shouldn't put something out on reddit that late at night without a source. Cheers! ",
"You're right, what is now Iraq/Iran (Mesopotamia and Babylon along the Tigris and Euphrates) and Algeria (over farmed by the Romans), used to be lush, pastoral land. So what happened? Most likely it was desertification caused by early agriculture. In short:\n\n - Over tilling the land leads to loose, bare topsoil\n - Wind/rain takes all that fertile top soil away\n - The same crop is grown year after year on the same land, depleting the soil of key nutrients needed for growing that crop \n\nWhen the land has been tilled and single cropped for centuries, the last of the topsoil erodes and the subsoil beneath is depleted of nutrients needed by native plants. Because no plants are growing, there are no roots and soil organisms like earthworms to keep the soil loose and porous for water infiltration. So the soils become \"hard-capped\" and water runs over, instead of into, the soil. The hard capping makes it even harder for plants to grow, starting a vicious cycle that leads to a desert. \n\nHow could you conclude agriculture is to blame? Scientists looked at pollen samples in lake beds and found a sudden drop in native forest and grassland pollen and a rapid rise of agricultural pollen. This corresponded with a major increase in the rate of sedimentation on the lake bed due to erosion.\n\nIf you want to learn more about it check out Dirt: The Erosion of Civilizations by David Montgomery, everything I've said here is pulled from that book. ",
"Anyone know why the US Southwest gets so much rain even though it looks like it’s in that desert ring?\n\nEdit: oops meant southeast lol",
"a new theory is that the Sahara was man-made through the introduction of livestock which ate the grasses causing a dry feedback loop\n\n > Growing agricultural addiction had a severe effect on the region’s ecology. As more vegetation was removed by the introduction of livestock, it increased the albedo (the amount of sunlight that reflects off the earth’s surface) of the land, which in turn influenced atmospheric conditions sufficiently to reduce monsoon rainfall. The weakening monsoons caused further desertification and vegetation loss, promoting a feedback loop which eventually spread over the entirety of the modern Sahara. Central to this cycle was the role that fire played in creating the new ecological circumstance. Although there is evidence for the presence of fires throughout all of human history, wild animals will not go onto a newly burned landscape because they would be easy targets for predators. However, pastoralists direct and protect their animals onto the newly regenerating landscape, altering the “ecology of fear.” This encourages scrub growth at the expense of grasses.\n\n > There is much work still to do to fill in the gaps, but Wright believes that a wealth of information lies hidden beneath the surface: “There were lakes everywhere in the Sahara at this time, and they will have the records of the changing vegetation. We need to drill down into these former lake beds to get the vegetation records, look at the archaeology, and see what people were doing there”.\n\n_URL_0_",
"To add to other responses, look carefully at the map. If you draw a straight line where the equator is, you'll notice that's where all the rainforests are. If you draw a curved line above the equator (representing the earth's curve), you'll notice that's where all the deserts in the northern hemisphere are including the ones you said and in southwest U.S./Mexico. If you draw another curve to the south of the equator, you'll notice that's where the other deserts are including Australia, south Africa, and the the hottest/dryest of them all in South America.",
"The sun hits hits the earth from directly above at the equator, heating the ground and sea. This causes water to evaoprate and rise as warm humid air. As it rises the air cools and forms clouds which eventually fall as rain, forming a lush green band at the equator. The cooled air flows away from the rising air at the equator and eventually decends as it becomes cooler and heavier. This air decends at roughly the same latitude above and below the equator; creating a band that is dominated by air that has already been stripped of moisture. This makes it harder for clouds to form or get to the point where they fall as rain, creating a desert. There is a further system below this creating the temperate forests and the desert regions at the poles.",
"It’s related to air circulation patterns. At the equator, the sun heats up the air and evaporates water over the oceans and continents. As the air rises, water vapor in the air condenses into cloud droplets, which form clouds, which create precipitation. After the air loses its moisture over the equator, the air gets pushed towards the north and South Pole. As it moves away from the equator, the air becomes colder and starts to sink over the subtropics (around 30 degrees north and south of the equator). The air is already dry, and cold, which means it can’t provide rain or even clouds to the subtropics. This is where you get deserts like the Sahara and the Atacama. The air eventually gets diverted back to the equator to go through this process again. The entire loop is called a Hadley cell and is responsible for the tropical rainforests along the equator like those found in South America and Africa as well as deserts in the subtropics in North America, South America, Asia, Africa, and Australia (I’ve no idea about Europe. They’re a bit too far north to be influenced by this.) \n\nIf you want to know more about this, here’s an article on the subject: _URL_0_",
"Iran's Caspian Sea coastline region along the north is lush and green; the Alborz mountains cause a rainshadow for the rest of the country",
"Once upon a time, there was this 'event' called the [5.9 kiloyear event.] \n(_URL_0_)\n\nThe 5.9-kiloyear event was one of the most intense aridification events during the Holocene. It occurred around 3900 BC (5900 years Before Present), ending the Neolithic Subpluvial. \n\nThe Neolithic Subpluvial was the most recent of a number of periods of \"Wet Sahara\" or \"Green Sahara\".\n\nWhile you're at it, check out the [4.2 kiloyear event.](_URL_1_) \n",
"I wish we could keep this near the top because I have two follow on questions related.\n\n1. Could the amount of sands in the deserts be contributing to global warming similar to the asphalts in our streets?\n\nI mean if you go to a patch of grass on a hot summer day - the soil and grass is cool to the bottom of your feet. \n\nBut if you walk on hot cement sidewalk or asphalt driveway it literally burns your feet at high noon - that absorption of heat has got to be contributing to global warming.\n\nAnd I never thought of it until I saw this picture today _URL_0_ - I was always thinking the sands acted as a mirror similar to ice and reflected the sun's heat energy - but sand is not a reflector of heat - it's an absorber - it you walk on stagnant *dry* sand barefooted - you can burn your feet - so the sands of the sahara are not reflecting that heat energy - they are absorbing it.\n\n\n\n((Not saying human's pollution and greenhouse gases are not contributing to global warming)) - certainly they are the main factor. But I wonder if the sands (and cement roads/streets etc) that cover *(random estimate here) maybe 15% of earth's land mass might also be contributing to global warming.\n\nSomeone mentioned above that planting trees that could live in the desert would be expensive and difficult - but I am now wondering if it might have a huge impact on the environment world wide?",
"Warm air rises.\n\nWarm air can hold more water than cold air. \n\nThe wind blows over the round earth left to right. \n\nSince it’s round, the wind curves towards the poles from the equator. \n\nSo what happens is air gets hot at the equator and starts moving towards the poles. If it can it collects water until it cant hold anymore and then rains it out. When it’s rained it’s guts out, that happens to be the towards the poles range where the deserts are. \n\nThe hot desert air try’s to collect water again, which makes the deserts more desert. The air continues to move towards the poles, getting colder as it gets further over the round earth. Cold air cant hold water as good as hot air, so it rains again. This is the temperate zone. Pine forests and such.\n\nNow the air is dry and cold as it continues to the poles. It picks up water over the dry tundras of Canada and Siberia but can’t hold much. \n\nThis process is what trade winds and “Hadley cells” are. Trade winds sailors talk about. Wind blowing from the equator toward the poles. Hadley cells are the water going up and down with the wind. Jungle, desert, temperate, tundra pole. \n\nMake sense? ",
"Take a look at _URL_0_ ... it actually covers why the saharan desert is growing, how the weather causing it is in a feedback loop, and their idea to reverse it.\n\nNot saying other comments are wrong, but i think this gives a better explanation as to the conditions than just \"cuz its hot\" which doesnt address other areas of the world on the same latitudes, other desert areas of the world on other latitudes, etc.",
"Most, if not all terrains where forests at some point in time, even in Africa to this day you can see there is around 40 meters of erosion, and a few tablelands are still standing. Deforestation from civilization is a cause for most of it. Central Mexico used to be forest, now it is arid. Canada and USA are swiftly catching up because of conventional agriculture and plowing that speed up the process. Modern Alberta, Canada used to be almost all forest now it is arid, Natives in both Canada and Australia both burned swaths of forest to clear it.\n\nNow when you look at the Sahara, know that we have had 14,000 years of people there, and at least 180,000 years of people before that, with an apocalyptic event, and the younger dryas ice age inbetween. A lot of Europe was deforested not only for agriculture, but also during the mini iceage that we had in the middle ages period. \n\nWhen a forest is cleared (for agriculture) it erodes the topsoil and exposes it to sun, wind, and rain that all accelerates the desertification process even more. A healthy forest floor will absorb rain, alowing it to evapotranspirate into more rain. \n\nTl;Dr humans not implementing rainwater harvesting techniques to the land they control. [This](_URL_0_) is a paper I am working on that explains how to regenerate the land to generate forest and more productive agriculture than what we have today, not ELI5.\n\nEdit: the natural procession of land is a forest. In 99% (everything but tundra/permafrost) will become a forest if humans are not part of the equation. Humans are not inheritly negative, we can do better with nature than nature can by itself, as described in the linked paper. ",
"Ohh, something I can comment on!\n\nThe sun makes the equator really hot and this, in turn, makes a lot of hot, wet air. Now think of your kettle when it boils, where does the steam go? It rises, and it's exactly the same at the equator! The hot, wet air rises up into the atmosphere.\n\nNow think about the mirror in your bathroom when you take a shower, what happens to it as you enjoy a long soak? It gets misted up. This is because the hot, wet air in your bathroom cools down and turns back into water, which condenses on your mirror. It's exactly the same at the equator! As the hot, wet air that has been rising begins to cool, it turns back into water and falls as rain. The equator is hot and also very rainy! This is why we find rainforests, mostly, near the equator.\n\nBut what happens to that Cool, dry air after it has rained? It can't sink back down to the equator because more air is rising beneath it. Instead it gets 'pushed' North and South from the equator where it can sink back down to ground level.\n\nBecause it already lost most of it's water, this cool, dry, sinking air can't rain North and South of the equator; and so this is why we tend to find deserts in these areas!",
"Hard to say the exact cause but it may be due to continental uplift of the region draining the old mega lakes. Much of the salty areas used to be seafloor until around the period of the yonger dryas climate disaster 13000 years ago. Here's a video with a hypothesis of where Atlantis went in context to what Africa used to look like. _URL_0_",
"One very recent example of a man made desert is the Aralkum Desert in Central Asia. As late as the 1960s the Aral Sea was the fourth largest lake in the world. The Soviets diverted the Syr Darya and Amu Darya rivers for the purpose of irrigation. The Aral sea was made up of northern and southern lobes and now only the northern lobe exists. A thin strip of the southern lobe remains in varying sizes. What was left is a dry lakebed made up of salt deposits and is heavily polluted by the remnants Soviet weapons testing. It is a source of massive health problems in the region.\n\nThese irrigation projects led to water levels dropping by as much a 3 feet per year. This led to massive ecosystem collapse. The rising salinity killed much of the remaining sea and plant life. \n\nBy 1997, in less than 50 years since the diversion began, the Seas size reduced to such an extent that the once massive lake was split into two separate lakes. The North (Lesser) Aral sea, and the South (greater) Aral Sea. The southern lobe, now cut off from any inflow source was almost totally dry by 2014. Occasional snow melts and ground water replenish the far western portion, but the vast majority of the former lake remains dry. For scale, those of us in north America could imagine all but the very northern portion of lake Michigan becoming a desert. \n\nThere are attempts underway to replenish the North Aral Sea. Dam projects are having some success. Salinity has been reduced even to the point that some commercial fishing is returning. The southern lobe however may be lost forever. This is considered one the greatest man made evnironmental disasters in history. \n\n_URL_0_\n\n",
"Deforestation and overfarming.\n\nThat area used to be the bread basket of humanity.\n\nIn some cases the earth was salted to kill everything.\n\n\nThe land is reclaimable, though ",
"If I recall correctly, it's basically because at certain latitudes the pressure is higher due to convection of air and stuff,leading to less clouds being formed which = less rain= desert.",
"That desert region is due to the same event that resulted in Humans getting down out of the trees and standing upright: Panama.\n\nWhen the Americas came together some 4mil years ago the West- > East flow of the Pacific could no longer continue straight through to Africa and thus the El Nino weather pattern stopped bringing as much rain.\n\n1) creation of Panama blocks W > E humidity flow\n\n2) region dries out overall, with some falling into desertification\n\n3) Africa-wide jungle breaks up and forms intervening savannah\n\n4) Humans evolve on savannah, spread across planet and devise Internet, asks climate question that wraps around to human evolution."
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5d7jrg | How much does a cat or a dog rely on smell to identify people, as opposed to vision? | For example, imagine the case in which a certain person of a household puts on all the clothes of another's - will the cat, or the dog, even for a moment confuse the people? | askscience | https://www.reddit.com/r/askscience/comments/5d7jrg/how_much_does_a_cat_or_a_dog_rely_on_smell_to/ | {
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"Seeing as a dog or cat can recognize you from far away, it can use sight and sound to positively identify a person. From what I've noticed, smell seems more important to identify a member of its own species. Smell probably indicates a lot about what the individual does not possess the ability to communicate about."
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9nuyhl | Was it okay to loot a slayed enemy during the middle ages? | If a knight or any other fighter killed an enemy in battle was it okay to take their armor and weapons? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/9nuyhl/was_it_okay_to_loot_a_slayed_enemy_during_the/ | {
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"Looting was not only okay, but an intrinsic and formally codified part of medieval warfare. Soldiers looted absolutely everything of value, both from slain enemies and from the unfortunate civilian population who happened to be in the way of marching forces. In the later medieval era, looting, plunder, and spoil were formally accounted for in a soldier's contract: he would recieve a certain share, another would be reserved for his captain, and the overall commander of the force would recieve another portion (the exact ratios and number of higher commanders taking a cut would vary). Soldiers looted partly to improve their own equipment (accounts of Agincourt say explicitly that English troops who did not have sufficient armor took the opportunity to loot armor from dead French soldiers), but primarily for their personal profit. The promise of pay far greater than normal military wages was a powerful motivation for soldiers to endure the hardship and risks that characterized a medieval campaign. Loot was not just limited to physical goods like equipment, jewelry, or wine, though. Capturing prisoners for ransom could also be extremely lucrative. The better known aspect of medieval ransoms are the more formal occasions when an important aristocrat was captured and held for enormous sums or political leverage . But common soldiers would also get in on the act by kidnapping local civilians near their camps and forcing their friends and family to pay up. This was not as lucrative as ransoming a king or prince but was far more accessible for the average soldier."
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1p1r5w | what are the differences between us civilian and military courts? | I'm pretty familiar with the US civilian judicial system (rules of evidence, witness testimony, etc.) and I would like to know how a military court is different. For instance: Does the prosecution have to disclose all the evidence to the defense? Thank you. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1p1r5w/eli5_what_are_the_differences_between_us_civilian/ | {
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"Courts martial (NOT court martials) aren't technically an arm of the U.S. judicial system. They're a component of military command; they exist as a resource for a commander to discipline his/her troops. They have their own rules of procedure and evidence. That said, the play-by-play of a court martial would look a lot like a regular ol' criminal proceeding.\n\nThere are, however, some big differences:\n\n* **No jury,** at least not in the traditional sense. In civilian criminal trials, the defendant has a right to a *randomly selected* jury of *peers.* In courts martial, the commander personally selects members of its panel (jury). Furthermore, these are not necessarily the *peers* of the defendant. The panels are usually composed of officers and veteran enlisted men. So if you're on trial as a private, don't expect to see any of your buddies in the jury box.\n\n* **Appeals are handled differently.** They are made to military courts of appeal, as opposed to a U.S. district or circuit court (for example). Decisions are ultimately appealable to SCOTUS only in rare cases. Instead, the Court of Appeals for the Armed Forces (CAAF) is usually the end of the line for appeals. The CAAF is as close to a civilian proceeding as most servicemen will get - it's a five-judge panel of civilian judges, and the defendant can opt for civilian counsel. Also, after a conviction at the trial level, you can \"appeal\" to the commanding officer, though this is less like a judicial appeal and more like a request for clemency.\n\n* **Venue and jurisdiction are kind of wacky.** Courts martial are held at whatever base the defendant is stationed at/reports to, which can lead to some wacky cases where you might have to fly to Japan to try a case for an assault that happened in Texas. The navy might be a little different than everyone else in this respect - I don't really know.\n\n* **Pretrial detention,** in my understanding, is a little more rigorous than it is in civilian courts. I don't think there's any sort of bail to speak of. That said, there's a general 120-day maximum for confinement prior to trial, but this may be exceeded if it's required to secure the defendant's presence at trial.\n\nThere are plenty of other differences, but I think these are the big ones. Hope this helps."
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1tapzb | How often did Vikings use horses? Did this differ in Scandinavia and the territories they raided and settled? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1tapzb/how_often_did_vikings_use_horses_did_this_differ/ | {
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"Horses are difficult to transport in ships. Particularly difficult in Viking ships. So, Viking raiders did not bring horses with them.\n\nThe Vikings seem to have tried to acquire horses after they landed on a raid, either by looting them or by taking them from defeated enemies. (As recorded in the Anglo Saxon Chronicles for 999 and 1010).\n\nThese horses were more often used for scouting or for the rapid movement of raiding parties rather than for fighting as mounted cavalry. \n\nThe Vikings did deploy a cavalry contingent at least once in battle though, at the Battle of Sulcoit in Ireland in 968. They may not have been very good cavalry. At least at the Battle of Sulcoit, the Vikings were lured into an ambush by the Irish, and lost both the Battle and the town of Limerick.\n\nThe Vikings used horses more for farming and transport than for fighting. The Vikings are thought to have introduced plowing with horses (instead of oxen) to the British isles. Legendarily, the Vikings adopted horses for ploughing because they were faster than oxen, and the Vikings could plough and plant their fields quickly and then go off raiding for the summer, before returning home in time for harvest.\n\nSource:\n\n_URL_0_"
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y6p7o | military numbering, regarding squadrons/wings/battalions etc. | I feel dumb (five years old?) for asking this, but when I read reports about how the "111th air wing intercepted [whatever]", I'm always left wondering if there are/were 110 other wings standing by. Same with squads, battalions, infantry divisions, etc. How are these numbers reached/calculated/set? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/y6p7o/eli5_military_numbering_regarding/ | {
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"It varies from military to military but generally speaking if you see something like the 111th Air Wing, it doesn't necessarily mean that there are 111 Air Wings. What tends to happen is that during large expansions of a military (say during a big war), new units will be created. These get numbered in a fairly logical sort and things make sense. However, when that military decreases in size (like after a big war), they don't go about decommissioning them in chronological order. So, for example, at the end of the war Air Wings 35 through to 75 are deemed surplus to requirement and disbanded but for whatever reason the 111th is retained. Thus, the 111th doesn't mean there's 110 other units.\n\nAs for things like regiments and battalions, this tends to vary more widely. Some armies (like the British) tend to go in for named rather than numbered regiments (although during times of rapid expansion a number system has been used) and so most regiments go by names like The Green Jackets or The Black Watch, while the US Army tends to stick to numbers. In both armies, those regiments will be made of Battalions and these will be numbered according to where they sit in the regiment. So for example, in the US 3rd Infantry Regiment there are at present three Battalions, the 1st, 2nd and the 4th. This is because the 3rd, 5th, 6th and 7th were disbanded in 1967 as they were deemed surplus to requirement. However, they could be reactivated. The important point is that you don't see big numbers in front of Battalions because regiments rarely have over 6 or 7 Battalions and Battalions are never referred to in isolation (saying your from the 1st Battalion would be meaningless as virtually every regiment has a 1st Battalion. However, saying 1st of the 3rd would make sense and confirm that you were from the 1st battalion of the 3rd Infantry Regiment). \n\nThe same rules apply for sub units of Battalions although Companies are usually lettered rather numbered.\n\nThe levels above regiments are brigades, followed by divisions, corps, armies and army groups. These are nearly always numbered."
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kbhwk | what is an 8-bit game? | If I understand correctly, the NES was an 8-bit console, SNES was 16-bit and this number doubled with each console generation.
My question is what does this mean? How could you possibly create a Mario game with only 8 bits (1s and 0s?)
I know I am missing something, what are those bits used for and what does it all mean!? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/kbhwk/eli5_what_is_an_8bit_game/ | {
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"So, a console is just a computer. A computer has many parts, one of these is the processor. The processor is what does the math needed for the video game. A processor can only work with so much data at a time, so many bits. The number of bits is not just 8. It just means the processor is only working with 8bits at a time. Modern day computers and consoles are 64bit(though some computers still only use 32bit). I hope this helps.",
"Inside a computer everything is represented by numbers. When people say that an NES was an 8 bit machine, all that means is that all the numbers inside an NES were 8 bits wide.\n\nIf you played the original Zelda, you probably remember that the most money you could have is 255 rupees. That's because your money was represented using an 8 bit number. If you have one on and off switch, it can be in two positions. If you have two switches, there are four combinations of positions. Three switches, eight combinations. Keep going with this, and when you get to eight switches there are 256 positions. For counting money, this means you could have anywhere from 0 to 255 rupees.\n\nAll this means is that if you wanted to do math with numbers bigger than 255, you had to use some tricks to get it to work. These tricks take a little more processing power. In old systems this processing power could be very precious, so game designers had to make trade offs. In Super Mario Bros. your score could climb well above 255, and the timer would count down from 300, but in Rad Racer, the top speed was 255.",
"Think of bits as \"digits\". (10 bits are about the same as 3 digits). \n\nPretend the NES is a \"three digit game system.\" This means that it's designed to work with numbers that are three digits or less. So remembering or doing math on numbers less than 999 is very easy and fast.\n\nThat means it's hard to work with numbers that have more than 3 digits, though. Let's say the game designer knows he'll need to work with the number 1000 at some point-- it won't fit in one 3-digit number, so the programmer must split it across TWO three-digit numbers. The first number can store the first three digits (the \"000\" part of the 1000), and the second number can store the second three (the \"1\" part). Then, any place the programmer wants the game system to do math to his stored \"1000\", he'll have to remember to command the system to do math on the first part, THEN on the second part. This is really inconvenient and much slower than working with smaller numbers.\n\nNumbers are very important in games, because *literally everything* in the game is stored as a number. This is because computers and game systems *only* understand numbers. Where is Mario in the level? He's at horizontal position #371, and vertical position #14. Which enemy did he just stomp on? Enemy #21. What kind of enemy is enemy #21? It's enemy kind #8 (a goomba). What does a goomba look like? It looks like picture #41. How do I draw picture #41? Put color #17 in the first pixel, color #2 in the second pixel.... etc. Everything is numbers.\n\nSo back to our digits-- this means it's really inconvenient and slow to have more than 999* of any given thing in our game. No more than 999 different colors. No levels wider than 999 tiles. No sprites with more than 999 pixels in them. No sounds with more than 999 distinct levels. Everything is \"blocky\" because you can only represent it in 1/999-size \"chunks\".\n\nIn reality, \"digits\" are bits. An 8-bit system can only store numbers smaller than 256 (2^8). A 16-bit system goes up to 65,535 (2^16). A 64-bit system goes up to 18,446,744,073,709,551,615! You may never need to store a number that large, but it means you can represent your game in very fine detail, and there are many more unique \"places\" in memory to store things like pixels, or points on your 3D character. Also, the game system can do math on many more \"digits\" in one step, making your game faster.\n\nHope that helps.\n\n *(yes, it's actually 1000 unique things, not 999, since 0 counts as a number too, but it's much easier to see the three-digit nature of \"999\").",
"So, a console is just a computer. A computer has many parts, one of these is the processor. The processor is what does the math needed for the video game. A processor can only work with so much data at a time, so many bits. The number of bits is not just 8. It just means the processor is only working with 8bits at a time. Modern day computers and consoles are 64bit(though some computers still only use 32bit). I hope this helps.",
"Inside a computer everything is represented by numbers. When people say that an NES was an 8 bit machine, all that means is that all the numbers inside an NES were 8 bits wide.\n\nIf you played the original Zelda, you probably remember that the most money you could have is 255 rupees. That's because your money was represented using an 8 bit number. If you have one on and off switch, it can be in two positions. If you have two switches, there are four combinations of positions. Three switches, eight combinations. Keep going with this, and when you get to eight switches there are 256 positions. For counting money, this means you could have anywhere from 0 to 255 rupees.\n\nAll this means is that if you wanted to do math with numbers bigger than 255, you had to use some tricks to get it to work. These tricks take a little more processing power. In old systems this processing power could be very precious, so game designers had to make trade offs. In Super Mario Bros. your score could climb well above 255, and the timer would count down from 300, but in Rad Racer, the top speed was 255.",
"Think of bits as \"digits\". (10 bits are about the same as 3 digits). \n\nPretend the NES is a \"three digit game system.\" This means that it's designed to work with numbers that are three digits or less. So remembering or doing math on numbers less than 999 is very easy and fast.\n\nThat means it's hard to work with numbers that have more than 3 digits, though. Let's say the game designer knows he'll need to work with the number 1000 at some point-- it won't fit in one 3-digit number, so the programmer must split it across TWO three-digit numbers. The first number can store the first three digits (the \"000\" part of the 1000), and the second number can store the second three (the \"1\" part). Then, any place the programmer wants the game system to do math to his stored \"1000\", he'll have to remember to command the system to do math on the first part, THEN on the second part. This is really inconvenient and much slower than working with smaller numbers.\n\nNumbers are very important in games, because *literally everything* in the game is stored as a number. This is because computers and game systems *only* understand numbers. Where is Mario in the level? He's at horizontal position #371, and vertical position #14. Which enemy did he just stomp on? Enemy #21. What kind of enemy is enemy #21? It's enemy kind #8 (a goomba). What does a goomba look like? It looks like picture #41. How do I draw picture #41? Put color #17 in the first pixel, color #2 in the second pixel.... etc. Everything is numbers.\n\nSo back to our digits-- this means it's really inconvenient and slow to have more than 999* of any given thing in our game. No more than 999 different colors. No levels wider than 999 tiles. No sprites with more than 999 pixels in them. No sounds with more than 999 distinct levels. Everything is \"blocky\" because you can only represent it in 1/999-size \"chunks\".\n\nIn reality, \"digits\" are bits. An 8-bit system can only store numbers smaller than 256 (2^8). A 16-bit system goes up to 65,535 (2^16). A 64-bit system goes up to 18,446,744,073,709,551,615! You may never need to store a number that large, but it means you can represent your game in very fine detail, and there are many more unique \"places\" in memory to store things like pixels, or points on your 3D character. Also, the game system can do math on many more \"digits\" in one step, making your game faster.\n\nHope that helps.\n\n *(yes, it's actually 1000 unique things, not 999, since 0 counts as a number too, but it's much easier to see the three-digit nature of \"999\")."
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7l5lz3 | in films how do they make background noises like wind so quiet compared to the actors voices? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7l5lz3/eli5_in_films_how_do_they_make_background_noises/ | {
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"This can be accomplished a couple of ways. One is by use of a shotgun mic that records sounds from a narrow direction, thus catching the dialogue clearly without too much background noise. \n\nAnother method is known as ADR, automatic dialogue replacement, where the actors will go through and record their dialogue again in a closed recording booth to be dubbed over their scene."
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3ddwkq | Did the Western NATO members ever explicitly or implicitly promise to the USSR that they would not expand the alliance to former Warsaw Pact members? | There seems to be a running narrative in Russia about the betrayal by the West. I've been looking around for information on this, as Putin has made statements about the broken promises of the West with regards to NATO enlargement. The NATO website has some good information, but they obviously have a stake in this issue. So did NATO leaders ever make explicit (or heavily implied) promises not to expand to former Warsaw pact members?
I realize this may butt up against the 20 year rule- but I'm mostly asking about the behavior of Western leaders in the time before the big NATO expansions in 1999 and 2004. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/3ddwkq/did_the_western_nato_members_ever_explicitly_or/ | {
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"Gorbachev says \"[No](_URL_0_)\".\n\n\nThere's an urban myth that NATO did promise they would not expand east. Those involved in post-Soviet discussions with western nations in the 90s do not confirm the story.",
"The closest thing would have been the clause in the 2+4 contract to only station German troops outside of the NATO command structure in Eastern Germany, as long as Soviet troops were present there. Foreign NATO troops are never to be stationed in former East Germany, according to article 5 of this contract. At that point, the Warsaw Pact (as well as the Soviet Union) was still intact though. I'd be surprised to hear that the Soviet leadership in 1989/1990 gave any thought about the possibility of Warsaw Pact nations wanting to join NATO."
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2brqld | Why doesn't Mercuries atmosphere explode if it contains hydrogen and oxygen? | According to this _URL_0_ Mercuries atmosphere contains fair amounts of hydrogen and oxygen. Why don't they react to water? | askscience | http://www.reddit.com/r/askscience/comments/2brqld/why_doesnt_mercuries_atmosphere_explode_if_it/ | {
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"The graphic you are looking at is very misleading because it shows only the composition of the atmosphere not the amount of atmosphere. Because mercury is so small, its gravity is not strong enough to keep any gasses associated with the planet. Mercury has the same amount of atmospheric gasses as our moon! [See here.] (_URL_0_). 1,000,000,000,000,000 times less than the earth. The \"atmosphere\" of mercury is barely different that that of deep space. There are such an extremely small (barely detectable) number of atoms that they rarely encounter each other (thus hydrogen and oxygen barely get a chance to react)."
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30ml8j | why don't all the cars in nascar go the same speed? | The cars are regulated. They're all built the largely in the same way. I understand that minor tweaks make a big difference. I also understand the skill of competitive driving, but why don't all the cars go the same speed? Why do certain cars drive slower? Why are certain teams and cars consistantly less competitive than others? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/30ml8j/eli5_why_dont_all_the_cars_in_nascar_go_the_same/ | {
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"just because you have two cars built exactly the same doesn't mean the driver is capable of driving the same lap speed. \n\nthe specifications only limit engine size and car weight and aero profile and tires. there's a lot that's not the same between each team's car. a more smooth aero profile makes a faster car on the straight. but it means less traction in the turn. a suspension adjustment can mean the car is quicker to turn, but more unstable at the limit. every component can have almost infite small adjustments and the combination of adjustments for every component is vast. \n\nin addition a race track is not a static piece of pavement. the heat and rubber deposit variation from \"the line\" and \"off line\" can mean the difference between making the turn and slipping. it's a difference of a couple inches. if the driver gets on the brake 1/10th of a second too early or slow on the accelerator, that can mean being in 2nd place or 20th place. ",
"The cars are governed, not built exactly the same. You can have different gearing, different angles of spoilers/air dams, different tires, a lot of different things on the cars, just the engines are the same.",
"The margins are very small but over a 3 hour race even the slightest skill advantage is really a large time difference."
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6ub81x | Why isn't humidity the same for the same temperature and pressure? | Why does the humidity not adjust by pulling in more water from lakes/rivers/pools etc until equilibrium is reached? That is if the humidity is below that threshold, it should draw more water vapor into the air until it is at that point? | askscience | https://www.reddit.com/r/askscience/comments/6ub81x/why_isnt_humidity_the_same_for_the_same/ | {
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"Equilibrium is more for the laboratory than for the perpetual changing world outside. \n\nSurface water is almost always evaporating, but that takes time, especially over land where lakes/rivers/pools are just a small part of the surface. (If there is enough water in the ground, transpiration by plants is important.) The humidity is, on the other hand, also removed from the atmosphere when it rains. _URL_0_",
"If you had an atmosphere with uniform temperature and pressure, you would eventually see the relative humidity reach 100% across the planet. But due to wind and sun, temperature and pressure are not uniform and humidity rises as water evaporates and plants transpire, but the changing air also removes water in the form of rain, snow, dew, fog, etc."
]
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tnib9 | How many times per second would a person have to
blink such that it was imperceptible to their vision... | ...assuming you ignored every other effect this would have on the eye (such as friction and lacrimation)? | askscience | http://www.reddit.com/r/askscience/comments/tnib9/how_many_times_per_second_would_a_person_have_to/ | {
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"Um, don't you mean: How many times per second would a person have to blink such that it was *perceptible* to their vision? You blink all the time without it being perceptible. \n\nAnd the answer to that question relates to the [flicker fusion rate](_URL_0_) would be difficult to state with any certainty. ",
"I only notice that I'm blinking just after someone points out that I don't usually notice when I blink & #3232;\\_ & #3232;",
"I think the relevant term you're looking for is frame rate. Just like a monitor has a frame rate (typically 60 hz: that means it refreshes itself 60 times every second, so you're getting 60 \"blinks\" every second), your eyes do too. I think there's some controversy as to whether there is a literal frame rate, but the fact remains that, experimentally, people can only process so many frames every second. If you lock your (monitor's) frame rate on something lower (say, 20-30 fps), it might look a little funny to you. Personally I notice an oily texture to the screen at this frame rate, but I've heard other people perceive it differently. Now you can set your frame rate really low, < 10 frames per second. Now videos/games/etc. look like slideshows.\n\nYour eye is capable of refreshing its input at [10-12](_URL_0_) frames every second, or 10-12 hertz. \n\nHowever this doesn't mean that blinking at less than 10 hz will make it imperceptible, as blinking isn't instantaneous. \n\n"
]
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49tl7n | How close to the Sun could a manned, contemporary spacecraft come before experiencing technical failures or crew deaths due to heat exposure? | askscience | https://www.reddit.com/r/askscience/comments/49tl7n/how_close_to_the_sun_could_a_manned_contemporary/ | {
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"Most probably, heat would be dangerous well before orbit of mercury (as current spaceships might not have the cooling / radiating out the heat capacity that is enough). Also, besides heat, crew and capsule will be exposed to ionising / particle radiation (either for normal sun radiation, or - even higher dose - from any solar flares that could happen) that could be well above what they can handle - and this would probably happen even earlier."
]
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6sgj5c | Why aren't pixels made up of 'RYB' LEDs instead of RGB ones? | Was wondering that since the 3 primary colours are red, yellow and blue would it not make more sense in some applications for yellow LEDs to be used instead of green LEDs for pixel based displays. | askscience | https://www.reddit.com/r/askscience/comments/6sgj5c/why_arent_pixels_made_up_of_ryb_leds_instead_of/ | {
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"RYB are the subtractive primary colors. [RGB are additive primary colors](_URL_0_). When mixing paint you are eating light of certain wavelengths leaving only what you desire reflecting...the more colors you mix the darker it gets. With light you are adding additional wavelengths of light, the more you mix the brighter and whiter it gets. \nRed light Plus green light yields yellow light. Red paint Plus green paint makes brown. ",
"Additive versus subtractive color. RYB (actually Magenta, Yellow, Cyan) are primary subtractive colors. Red paint isn't red light, and yellow paint isn't yellow light. Magenta ink/paint is actually anti-green (it absorbs green), yellow is actually anti-blue, and cyan is actually anti-red. If you combine magenta and yellow paints you are really combining anti-green and anti-blue, so those colors are absorbed whereas red is reflected, so you get red.\n\nHowever, the rules are opposite for additive colors where you are generating light that is mixed. Red is red, green is green, and blue is blue. Combing red and green light you get red-green light which is just yellow.\n\nHopefully that makes sense.\n\nEdit: you can play around with this a bit on your own. For example, try mixing together different paint colors to see what the result is (hint: it's generally always darker). And try painting cards that you use to try to reflect light onto the same spot, or use ink to color a transparent filter over a flashlight and see what happens when you combine different light colors. Compare that to what you get when you mix the paints/inks together instead.",
"This is basically additive and subtractive light.\n\nIf you mix red and green paint together you are simply adding more pigments, and the result will come out brown. This is because red paint doesn't create red light, it just absorbs everything else.\n\nHowever with light if you shine green and red light together you truly \"add\" the colours together resulting in yellow. \n\nIt's a bizarre concept but basically for projecting light you always use RGB base colours.",
"The answers here are not really getting at the *fundamental* reason why the colors are RGB. In truth, the reason is because of the way the human visual system works.\n\nIn your eyes, you have two different kinds of cells in the retina that detect light: the rods, which are sensitive over a wide range of colors, and the cones, which are each sensitive to a narrower range of colors. It just so happens that each cone cell is sensitive with a peak at either red, green, or blue. (The rods can tell you how bright or dark something is, but they can't distinguish colors.)\n\nSo, back in the 1920s-1930s, researchers did some work on characterizing the human visual system's response to colors. They came up with [this chart](_URL_0_), which shows (for a particular saturation/luminance level) the various colors that a person can see. (Ignore the triangle for the moment.)\n\nThe round edge of the chart shows pure single-wavelength (\"monochromatic\") colors. They're labeled with the wavelengths of light as you go around. These are colors that an individual LED or laser can emit. Some phosphors also have a response pretty close to this line. Along the bottom, the straight line is the colors you get if you combine the reddest red you can see with the bluest blue. These colors are \"nonchromatic\" in the sense that it requires a combination of wavelengths of light to get these colors. You can't actually make an individual laser or LED that produces these colors on its own, but you can combine multiple ones to get these. Everything in the middle of the chart results from combining multiple wavelengths of light in varying amounts, and you can generally get these colors in multiple ways.\n\nThe last portion of this puzzle is related to the triangle that you see. This is the Adobe RGB color gamut. The corners of the triangle are called stimulus values. Each one refers to the wavelength produced by an individual red, green, or blue pixel in an LCD that conforms to the Adobe RGB gamut. You can get any color within that triangle, by combining those three colors in varying amounts. As you can see, this isn't all the colors that humans can see, but it's a wide variety. But you can see from this triangle why green was chosen instead of yellow: a triangle that went from red to yellow to blue would be much smaller and would exclude a lot more colors compared to RGB.\n\nNote that the choice of the corners of the triangle is also an engineering design choice, based on what devices are available for producing light of those colors. In the earlier days of color TVs, this was based on the color phosphor chemicals that were available. These days, it's based on the available colors of color filters, LEDs, and OLEDs. Also, it's possible to have more than 3 stimulus values, by having more than 3 colors of LED, for example. Many printing technologies use several colors of inks (which gets into complementary colors and other stuff) to bound out a larger shape on this diagram with a polygon with more sides."
]
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"https://en.wikipedia.org/wiki/CIE_1931_color_space#/media/File:CIE1931xy_CIERGB.svg"
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3kbk3c | do i lose my information on the cloud if the data storage center where my data is stored is destroyed | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3kbk3c/eli5_do_i_lose_my_information_on_the_cloud_if_the/ | {
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"Typically, a good cloud storage provider will have data backed up/replicated to other data centers. Plus, multiple layers of redundancy throughout their servers, disks, network equipment, etc.\n\nI don't know the specifics of what Google, Microsoft, Amazon, etc have in place. I would assume they could still withstand some data center damage/downtime. \n\nCompanies would negotiate availability into their service agreements with the cloud proved. But if you're talking about your personal data, I'd recommend always keeping a copy yourself.",
"Consumer-level cloud storage through companies like Google, Amazon and Apple is stored redundantly at multiple sites. To destroy the photos you took on vacation would require an asteroid-strikes-the-Earth level of catastrophe - or a decision by your provider to delete that information.\n\nYou can buy cloud contracts that designate a specific server located in a specific building. However, such contracts aren't normally for cloud storage but for location-specific services. If you're running an online game, you'll buy servers in a building somewhere near your player base. If those servers get destroyed, your service will be disrupted but you'll still have all your information.",
"Like mentioned, the major companies have secure backup redundancy. But if put your data on Hanks Cloud Data Service, and Hank didn't have any backups or redundancy, then once Hanks server, that he located in new orleans, gets flooded from katrina and goes down, your data is lost.",
"If you have a really, _really_ crappy 'cloud' contract which only stores your data at one data centre, with no off-site backups, then yes.\n\nIf you have a fairly crappy cloud contract which only stores your data at one data centre, but they at least have a backup routine, then no-ish. You might have to wait a week while they fish a tape out of a warehouse, and when they do retrieve that, a little bit of the data might be gone. You would lose everything from the day it was destroyed, if they only took off-site backups once a day, for example.\n\nIf you have a reasonable 'cloud' contract then you would expect data to be mirrored across multiple data centres at all times, in which case one of them can be destroyed and you lose, or even notice (perfect case) nothing.",
"Depends. If there are no backups or the backups are unusable, and there are no duplicate data centers to duplicate the data, the yes. \n\nServices like One Drive and Google backup your data across multiple data centers, then backup those data centers data locally as well. Worst case scenario, data that has only just recently been uploaded is vulnerable, because there wasn't enough time to fully duplicate the data. \n\nBut things can still go wrong. A recent heavy lighten strike at a Google data center caused them to lose a small amount of data that didn't have time to get fully backed up . "
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2nwzz4 | how does radioactivity work | If radioactivity is a decaying atom. What is left behind at sites like chernobyl. What causes some atoms or isotopes of atoms to be radioactive while others are not? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2nwzz4/eli5_how_does_radioactivity_work/ | {
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"Some atoms are just unstable and will eventually break apart. Imagine them like a bunch of legos chained together and being spun. Some configurations will allow a little piece to go flying off while others will stay together. \n\nAt Chernobyl, Uranium atoms were being split in half in the nuclear reactors. When uranium splits in half, the two smaller atoms that remain (each being about half the size of U) are typically unstable (they have too many neutrons). So they convert neutrons to protons in what we call *beta decay.* This happens slowly and releases some energy as it goes. That energy can cause biological damage and is therefore dangerous (especially if ingested). ",
"Basically, what happens is that certain elements are unstable, and to increase stability, they release particles and energy, known as radioactivity. This happens because there are too many particles in the atom for it to be stable.\n\nIt's lke a crowded elevator. Since there are so many people, everyone is uncomfortable, and some people will just leave the group instead of sticking together to go all the way to the top.\n\nEventually enough people will leave, and the elevator will be comfortable again. This is how lead is formed; it's uranium that has released enough particles to make it 'stable', or comfortable enough for the particles to stay together without losing any more. ",
"Radioactivity is usually caused by an unstable nucleus. This is caused when the nuclei are very large (ie Uranium, Plutonium, etc.) or if they are poorly assembled with an unstable construction with excessive or lacking neutrons (Potassium 40). When an atom decays it separates into two particles, a (often) hydrogen nucleus and another element slightly smaller. Chernobyl hosts a lot of strontium and cesium which are the products of a nuclear reaction. This is different from a decay scheme. Large elements like Uranium and Plutonium split into large chunks like cesium and strontium. Those are the materials that make sites like Fukushima or Chernobyl.",
"The simple explanation is that there are three forces at play: the strong force, the weak force, and electromagnetism. Now, the strong force keeps the nucleons together, so the component quarks can never be seen (confinement). A small excess force, called nuclear force, \"spills over\" from this. The electromagnetic force tends to drive apart particles with the same electric charge, like protons. But, if you had only the nuclear force and electromagnetic force, nuclei would be either perfectly stable, or perfectly unstable (they would break before or very soon after being formed). Conservation rules say neither force can change the quark count, quark flavor or particle charge. If you have two neutrons and one proton in a nucleus, the rules say that you'd always end up with a tritium nucleus that can't decay, since you can't have strong force or electromagnetic force change a neutron into a proton. So, the explanations in this thread about the nuclei being *inherently* unstable are not really correct, since that would imply only extremely fast radioactive decay.\n\nEnter the weak force. This is the only force that can break the rules for conservation of flavor. One of the down quarks can emit a weak force W- particle, and turn into a up quark, which accordingly means that a neutron turns into a proton. Now, the W- particle is relatively massive (and by E=mc2, has high energy), so it quickly sheds its energy by decaying into an electron and an antineutrino. (Notice how charge and lepton number are conserved by emission of a charged lepton + uncharge antilepton. Weak force can't break these laws)\n\nSince the weak particle W- is very massive, it takes a long time for one to appear, and that's why a tritium nucleus has a half-life of 12 years.\n\nAs for the ultimate *why*, the reason is the so-called anarchistic principle of quantum mechanics. It says that if something can happen - the event doesn't break conservation laws - it eventually will. Only the *rate* is set by the thermodynamic favorability. Kind of like that someone will eventually be hit with a meteorite, no matter how uncommon that is. (That's also a somewhat confusing example since quantum mechanics implies someone will be hit by a meteorite *from below*, to be precise; getting hit by a meteorite from the sky is always thermodynamically favorable. Quantum mechanics allows a probability also for events that aren't.)"
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3ys0b0 | Why are Spanish and Romanian so similar linguistically? | [deleted] | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3ys0b0/why_are_spanish_and_romanian_so_similar/ | {
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"So is Italian and French.\nThese languages all come from Latin, there called Romance Languages.\nThe counter part for English is Germanic Languages, as in German, Dutch, Swedish, and so on.\nHead over to [/r/linguistics](_URL_0_) for further understanding! "
]
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fmr8y | Questions about sperm storage. | I'm talking about the facilities that specifically offer people to store their semen in a frozen state, like 'sperm banks'.
Is there any kind of gradual damage occuring? For how long sperm can be stored without losing its characteristics, and what makes that period definite? | askscience | http://www.reddit.com/r/askscience/comments/fmr8y/questions_about_sperm_storage/ | {
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"The most fundamental damage for sperm would be that they die, which would mean they're just useless.\n\nIf they're not dead, freezing them and thawing them could affect their characteristics like motility, etc and this could easily affect their ability to fertilize the eggs.\n\nBut whether this would actually damage the DNA (thus affecting the offspring's health)? Probably not. \n\nAgain, once its frozen (presumably in liquid nitrogen at -170degrees), it should not depend how long its been frozen. It would be the act of freezing and thawing that would do the most damage, I think."
]
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] | |
4zir2v | How many of Great Britain's colonies successfully staged an armed rebellion? | Aside from the US. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4zir2v/how_many_of_great_britains_colonies_successfully/ | {
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"What is your definition of success? independence? autonomy? representation? change some law or behavior in how the colony was being treated? simply revolting against leaders in the colony itself?",
"I suppose you could include Rhodesia, but that wasn't really an 'armed rebellion' per se. Rhodesia (now Zimbabwe) had had self government since the 1920's, but by the 1960's the debate had shifted to the conditions for full independence. Her Majesty's government insisted that majority rule (IE giving franchise to the blacks that comprised 95% of the population) was a necessary condition, the white government of Rhodesia found this unacceptable. \n\nIn 1965, the white government unilaterally declared independence from Great Britain, and successfully ruled the country while conducting a guerilla war against black nationalists until 1979, when the government was dissolved as part of the Lancaster House agreement to transition to majority rule. \n\nHowever, I doubt this example really meets your criteria for 'armed rebellion'. Britain never undertook military action against their errant colonists - their actions were limited to economic sanctions and diplomatic pressure. "
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vuqv0 | Why is 3-4pm the hottest part of the day, and why isn't it noon? | askscience | http://www.reddit.com/r/askscience/comments/vuqv0/why_is_34pm_the_hottest_part_of_the_day_and_why/ | {
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"There is a lag period in the time it takes the land to heat up, just like how a frozen pizza in the oven takes time to come up to temperature. At noon the land is still lagging behind but the sun still has plenty of energy to heat the surface even though it slips towards the horizon as the afternoon progresses. By 3 or 4 the solar energy has pretty much maxed out the amount of heating it can do and the land has had several more hours of strong solar energy input into the system. "
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3fu1hm | How do we study the history of societies who have never had writing? | For instance, the native North Americans. Is it just anthropology + archaeology + whatever literate cultures have written about them? Or is oral history ever considered reliable enough to take into account? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/3fu1hm/how_do_we_study_the_history_of_societies_who_have/ | {
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"text": [
"hi! do consider x-posting this question to our sister sub, /r/AskAnthropology. While there are some anthropologists and archaeologists here, it's worth tapping into more over there."
]
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[]
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1as26r | Why does Taiwan seem to have the most mutually friendly contemporary relationship with Japan, out of all the countries the Japanese Empire had previously occupied? | Just read [this post](_URL_0_), and recently studied post-WWII Japanese/Korean literature in school. I'm Taiwanese myself and have always been intrigued by how much the older generations seem to idolize all things Japanese, and how the younger generations feel a sort of awe towards Japan. I grew up vaguely knowing that the Chinese hated the Japanese, and the Koreans hated the Japanese, but never understood why the Taiwanese don't considering they were also occupied. From the way I'm seeing it Japan could have treated Taiwan a whole lot worse? Is that true, and if so why didn't they? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1as26r/why_does_taiwan_seem_to_have_the_most_mutually/ | {
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"Don't quote me on any of this, i'm not historian or history buff, but this is from what I understand. Even before WWII, there were many conflicts between Japan and much of Asia due to territory. During the first Sino-Japanese war (late 1800s), Imperial China lost and ceded the island of Taiwan to the Japanese. Of course, there was a whole lot of anti-Japanese sentiment on the island at first (plenty of armed resistance and incidents). But the Japanese empire was trying to turn Taiwan into a 'model' colony and assimilate the people/culture with their own. As a result of Japanese rule, there were lots of improvements to the infrastructure, transportation, agriculture, education, health, etc, all of which was to modernize Taiwan (Taiwan before this was pretty rural). Pretty much if you learn Japanese, follow the rules and keep your head down, life generally improved post Japanese occupation. \n\nTo me, I believe this is the reason why many of the older generation in Taiwan don't see Japan as an enemy. The younger generation could care less. Their grandparents might have an opinion, their parents may or may not, but the kids (Generation Y) generally don't know much about the history. Their views are shaped on popular culture, food, entertainment, etc. \n\nThe same can be seen in China and Korea (for younger generations), but because they faced much harsher Japanese atrocities, I think the anti-Japanese sentiment is still prevalent, especially with the older generations. "
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obena | What's the view like from the edge of our galaxy? | If you were able to journey to a star system on the very edge of our galaxy and look out into space, would the other galaxies out there look like stars, i.e. pinpoints of light?
In other words, when you look at a picture like this one of the [Andromeda Galaxy](_URL_0_), I assume all the stars in the foreground are actually in the Milky Way. But if you move out of the Milky Way, at what scale would you actually see the form of a spiral galaxy out in space? | askscience | http://www.reddit.com/r/askscience/comments/obena/whats_the_view_like_from_the_edge_of_our_galaxy/ | {
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"We're fairly close to the edge of the Milky Way, and most other galaxies already look like points of light to the naked eye when bright enough to be visible.\n\nThere is no point within the milky way from which you could get a view of the spiral structure.\n\nThe structure would be quite visible from, say, 25,000 light years out along the axis of rotation, though there's really no hard threshold there.",
"We're actually pretty close to the edge of the Milky Way, so I don't imagine that it would look terribly different from what we see already.",
"You can see the Andromeda Galaxy without a telescope, but it doesn't look like a pinpoint of light. It looks like a white cloud and occupies an area in space that is several times larger than the moon, but you don't see any spiral shape. I still don't see any spiral shape with a 6 inch telescope."
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8ii3ow | why sometimes ice cubes in the freezer, freeze perfectly and come out in one easy piece, where as other times they break into dozens of pieces leaving you with ice chips and not cubes? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8ii3ow/eli5_why_sometimes_ice_cubes_in_the_freezer/ | {
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"When you let the ice trays sit out and get to room temp before refilling them, the cubes tend to come out intact. If you immediately refill them while they are still cold they tend to shatter into pieces. I don't know why, but this is my experience."
]
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27rzvh | What was the nature of warfare the British faced when conquering India? Did they have to develop a wide range of new doctrine and equipment to deal with the pitched/guerilla warfare they faced? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/27rzvh/what_was_the_nature_of_warfare_the_british_faced/ | {
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"text": [
"I was recently reading a Richard Holmes book called Sahib, which talked about this topic. So what follows is a very brief summary of that.\n\nEarly on (1750s - 1850s), in southern and central India, warfare wasn't hugely different to how it was in Europe. Many Indian states had armies trained to european standards by (sometimes ex-British military) european experts. The main difference being that the Indian states often had the edge in artillery, as they could produce guns locally. This meant that British tactics had to be much quicker and more aggressive, so as to close to melee distance and rob the cannons of their advantage as fast as possible. I've not heard many accounts of the usual two (or three if earlier) rank line, stationary, being very popular, however anti-cavalry squares were used just the same as in Europe.\n\nAs British control began to reach the mountains to the north of the subcontinent, and the enemies faced by were more often tribes than princely states, things started to look more like a form of guerilla warfare that we would recognize today, with the British forces aiming to pacify often already conquered areas of this northern frontier. In these areas the British heavily relied on locally recruited irregular fighters (as opposed to the professional european style sepoys of further south, who made up the bulk of the British and company armies in India), most famously mounted ones, to level the playing field. These men were usually loyal to their charismatic commanders, rather than the British state.\n\nThe only example of new equipment that comes to mind was the implementation of regulated water carts manned by (exclusively Indian) men dedicated to that task, this allowed long marches under the Indian sun to be conducted with fewer losses.\n\nHope that answers your question\n\nThis was typed up on my phone, sorry for any mistakes."
]
} | [] | [] | [
[]
] | ||
aocsvg | why does the first patch of pancakes come out spotty and the later batches come out a perfect golden brown? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aocsvg/eli5_why_does_the_first_patch_of_pancakes_come/ | {
"a_id": [
"eg06cgi"
],
"score": [
8
],
"text": [
"A combination of too much oil, an unevenly heated pan, and batter that hasn’t “rested” long enough before cooking.\n\nExcess oil in the pan causes the first pancakes to not cook nicely. More is not better. Those first pancakes absorb that excess oil while the pan heats up properly, and that leaves a perfect pan for subsequent batches.\n\nLet your batter rest for 10-15 mins, heat your oiled pan to the right temperature, and then wipe out excess oil. That should result in a nice first batch of pancakes."
]
} | [] | [] | [
[]
] | ||
sfiig | Why does alcohol hit harder when consumed after a hard cardio session like running 5 miles? | I actually try to run or swim before going out drinking now to minimize the number of drinks it takes for me to feel good. Is it hurting my body in anyway? Planning to join a local hashing chapter too. | askscience | http://www.reddit.com/r/askscience/comments/sfiig/why_does_alcohol_hit_harder_when_consumed_after_a/ | {
"a_id": [
"c4dnh29"
],
"score": [
2
],
"text": [
"Long stressful exercise can leave you very dehydrated, especially if you are sweating during the workout. Dehydration will cause the alcohol in your blood to be in a larger concentration, thus amplifying its effects. I'm not sure of the medical issues of alcohol consumption with dehydration though but i'd advise drinking some water after you exercise just to be safe. "
]
} | [] | [] | [
[]
] | |
3032dr | why can some people eat 2 meals a day while i have to eat 5+ meals a day to not stay hungry? | Assuming every meal is about 500 calories. I'm not that big either, just 5'5 weighing at about 145 pounds and these guys are 6 foot weighing at about 180+ sometimes they don't even eat they just eat a big patty for example | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3032dr/eli5_why_can_some_people_eat_2_meals_a_day_while/ | {
"a_id": [
"cpondcn"
],
"score": [
4
],
"text": [
"Are you 17? Because my 17-year-old eats like there's an alien in him. Not kidding. He came home yesterday and ate half a lasagna and a roast beef sandwich \"as a snack\"."
]
} | [] | [] | [
[]
] | |
bztdtb | what is it about john carmack's code that makes it so special? | Is there anything special or even transcendent about it, or did he just basically set everything out in an elegant and well-planned fashion? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bztdtb/eli5_what_is_it_about_john_carmacks_code_that/ | {
"a_id": [
"eqx1bdn",
"eqx2073"
],
"score": [
5,
4
],
"text": [
"You know how we have all those nice looking 3D games today? A modern computer has a special graphics processing unit designed and built specifically for doing the calculations to draw those worlds. For example, [here are specifications](_URL_0_) for a pretty nice one (RX Vega 64).\n\n- It has 64 \"compute units\"\n- Each compute unit runs 1200 million instructions per second.\n- The compute units and memory are designed specifically to do 3D graphics calculations\n\nJohn Carmack figured how to do this on a regular computer in 1993:\n\n- You have one \"compute unit\"\n- The compute unit runs 10 million instructions per second.\n- The compute units and memory are the regular stuff of a general purpose PC.\n\nBeing able to do 3D graphics at all in that limited setting is amazing programming feat. He wasn't the only or first person working on it, but he's famous for a couple reasons:\n\n- The games his company created were a new kind of video game called \"First Person Shooter,\" no one had made this kind of game before, it's been really popular ever since, hundreds of variations on that theme have been made.\n- A big part of the reason no one did it before, was that kind of gameplay meant getting the right kind of 3D graphics to run fast enough on a regular computer. Carmack figured out how to do that using programming, a lot of early 3D FPS games either bought his code, or waited until computers / consoles were faster and started using special hardware to help with 3D graphics.\n- Carmack eventually released his games' code as open source, so people could look at it and see all the clever tricks he used.\n- His games were incredibly popular and famous, people wouldn't talk about Carmack much / at all if Wolfenstein / Doom / Quake had only sold a few thousand copies.",
"He's just very good at coming up with good tricks. DOOM for instance was a very remarkable achievement -- the hardware back then was extremely slow compared to modern one, and it took a lot of tricks to make things work decently well. Working within those constraints and producing that kind of result is remarkable on its own, which is why DOOM was a gamechanger.\n\nHere's one famous [piece of his code](_URL_0_)\n\nJust try and figure out how that works without actually reading the explanation."
]
} | [] | [] | [
[
"https://en.wikipedia.org/wiki/List_of_AMD_graphics_processing_units#Radeon_RX_Vega_Series"
],
[
"https://en.wikipedia.org/wiki/Fast_inverse_square_root#Overview_of_the_code"
]
] | |
27ap42 | Why do only a few concentrated acids dissolve glass? | I'm assuming it doesn't have anything to do with the pH of the acids, since triflic acid is stable in glass while hydrofluoric acid eats through it. What, chemically, allows some acids to react with the oxides in glass? | askscience | http://www.reddit.com/r/askscience/comments/27ap42/why_do_only_a_few_concentrated_acids_dissolve/ | {
"a_id": [
"chz084e",
"chz093d",
"chz0pc0"
],
"score": [
14,
3,
4
],
"text": [
"Common glass consists primarily of silica (SiO2). In order to dissolve glass you must break the Si-O bonds in silica. These bonds are very strong, so you must form even stronger bonds for dissolution to occur. Si-F bonds are also quite strong. When HF reacts with silica it will form H2SiF6 or SiF4. Both are water soluble which means that a fresh surface of SiO2 will be exposed to attack by HF.",
"Glass is made up of Silicon Oxides, and the Si-O chemical bond is incredibly thermodynamically stable, over 450 kJ/mol. For contrast, a carbon-carbon bond is only 350 kJ/mol. This means that the most energetically favorable state typically has the glass as nonreactive, since it is already in a very low energy state.\n\nHowever, silicon has a very high affinity for fluorine, with a Si-F bond strength of over 550 kJ/mol. In reaction with fluorine based acids, the silicon in the glass will react and dissolve into the acid solution, eating away the glass.",
"First of all it is worth noting that the concentration and the strength of the acid are not especially relevant. HF(aq) is considered to be a relatively weak acid despite being very corrosive (an acid is weak or strong depending on how likely it is to lose a proton and form ions - HF does not fully dissociate in water, unlike say HCl). Also even a relatively low concentration hydrofluoric acid will eat glass. \n\n\nIn hydrofluroic acid, HF and H*_2_*O combine to give H*_3_*O^(+) and F^(-). Free fluorine is about the only element electronegative enough to oxidise an oxide, ie the silicon dioxide that glass is made of will react to give silicon fluorides which will dissolve in water (or evaporate). \n\nOn the other hand triflic acid is a very strong acid - it really wants to get rid of a proton, but what remains CF*_3_* SO*`-`_3_* is not an oxidising agent, and even is it were would not not oxidise a stable oxide like SiO*_2_* as there is no free fluorine there. \n\nThat said fluoroantimonic acid is a strong acid and that does eat glass, but again it has those pesky free fluorines"
]
} | [] | [] | [
[],
[],
[]
] |
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