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5thwk3 | how was anime able to distinguish itself from animation in other countries? | I've been into anime for awhile now, but something that I've always been curious about is why Japanese animation was able to separate itself to be considered its own medium, unlike animation from, say, Russia or France? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5thwk3/eli5_how_was_anime_able_to_distinguish_itself/ | {
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"It's actually really straight-forward and simple:\n\nIn Japan, cartoons are all called \"anime\", short for \"animation\". When they export animation to other countries, they still call it \"anime\" instead of using each country's colloquial terms.\n\nThat's ... pretty much it."
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ri92w | Is the Mega Millions ($500 million jackpot) worth buying tickets based on "pot odds"? | In poker, you make decisions to call based on pot odds. Based on this concept, it would make statistical sense to buy a ticket assuming there is only 1 winner. (After fees for the lump sum and taxes, the prize would still be over the $200 million)
Does the same concept apply for the lottery or does the infinitesimally low chance of winning (1 in 176million) make it irrelevant? | askscience | http://www.reddit.com/r/askscience/comments/ri92w/is_the_mega_millions_500_million_jackpot_worth/ | {
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"Pot odds are just an expected value calculation.\n\nTaking your values, $200 million lump sum jackpot and 1/176 million odds, then yes, your expected value is more than the $1 ticket. $200/176 = $1.14\n\nOf course, this calculation is irrelevant for the lottery because the odds of winning are so miniscule and the jacpot is so large; the expected value number will never play out for 1 individual.",
"When it comes to gambling the house always wins, there is no charity in lottery. It must be profitable for them, otherwise there would be no lottery.\n\nIn other words it's like a gigantic collection of $1 from every player which would go to one lucky guy (and for the house).\nI wouldn't say any gambling based more on luck than mathematics is worth it.",
"At those odds, it's more about superstitious luck than mathematics and statistics. With that being said, it should be noted that your chance of winning ALL of the money decreases as the pot increases simply because more people are playing with higher jackpots (more players means a larger statistical chance of more than one person winning the jackpot). You need to take that into consideration instead of relying solely on your odds against the pot. You don't know how many other players are betting against you. "
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vamz0 | How could you freeze in space? | so a thought just crossed my mind, if a object containing heat (like a *fresh* unprotected human body) was in space, how long would it take to freeze? since there is little matter floating around for a body to conduct it, wouldn't it loose heat very slowly?
| askscience | http://www.reddit.com/r/askscience/comments/vamz0/how_could_you_freeze_in_space/ | {
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"The body would loose heat by emitting infrared radiation. Over time, the body's temperature would asymptotically approach a point where the body was emitting as much radiation as it was taking in, and would be at equilibrium. I think is is something like 2-3 kelvin. I don't know how quickly this would happen but significantly more quickly than if there was just matter conducting heat out of the body. Evaporative cooling would also play a role, possibly larger than that of radiative cooling, but that is more specific to animals. A fresh human ejected into space would have much more to worry about than heat loss, the vacuum would be a much more imminent worry."
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2ddnzz | Does Detox Tea actually do anything or is it bullshit? | I enjoy tea and try all different kinds. I purchased one called Detox. It tastes good but is the "detox of liver and kidneys" part just pseudoScience and Homeopath BS? | askscience | http://www.reddit.com/r/askscience/comments/2ddnzz/does_detox_tea_actually_do_anything_or_is_it/ | {
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"It's a bunch of junk. Tea can be good for you, but anything advertising \"extra benefits\" are just blowing hot air.",
"I think it would depend on what herbs/roots/leaves comprise the tea mixture. There are many biologically active compounds in nature known to alter physiology and I'm sure some compounds would potentially affect the liver and kidneys considering there roles in the body. But most likely it's BS.",
"A good rule of thumb is that if a product says that it removes toxins without telling what toxins are being removed from where, than the product is probably BS.\n\nI'm sure there are some exceptions, but I can't think of any.",
"Aside from tea, here is a commonly available supplement which has detoxifying effects supported by sound toxicological science. \n\nWhen the body recognizes a given toxin within the body, it has various ways of metabolizing and excreting the toxin. One of the most important ways is known as glucuronidation. It involves hitching large or poorly-water-soluble molecules to a \"chaperone\" known as glucuronic acid which IS water soluble, thus helping to pull the toxin out of the body. \n\nHowever, gut bacteria can throw a wrench in this process. Some of them have an enzyme called B-glucuronidase which destroys this helpful linkage between a toxin and glucuronic acid, and sends the toxin back to the liver (enterohepatic circulation). \n\nCalcium D-glucarate, the supplement, is metabolized to a chemical (D-glucaro-1,4-lactone) that inhibits the B-glucuronidase enzyme and allows toxins to continue \"holding hands with their chaperone\" and leave the body. \n\n_URL_0_"
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2a22e6 | How does mint temporarily clear nasal congestion? | Title says it all. | askscience | http://www.reddit.com/r/askscience/comments/2a22e6/how_does_mint_temporarily_clear_nasal_congestion/ | {
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"This is actually a pretty interesting question. \n\nIn your airways there are quite a few different populations of receptors. Collectively they provide information on potentially damaging stimuli (eg, detection of chemicals and other irritants by C-fibres), lung capacity (lung volume and air flow are \"measured\" by Slowly and Rapidly Adapting Receptors (SAR and RAR)), as well as temperature.\n\nIt is a particular group of temperature receptors which are responsible for the feeling that mint clears nasal congestion. These receptors, the \"cool or menthol\" receptors (because they are activated by cooling and also menthol), are found in the upper airways. When you breathe in the receptors are exposed to the colder (below body temperature) air. Your body uses this information to \"know\" that you've inhaled.\n\nWith a blocked nose, the feedback from the cool receptors is blocked, which is one of the reasons you feel you can't breathe as well. Most mints however contain menthol (I believe it's the active ingredient?), which stimulates the cool receptors. As a result, you get the sensation of air flow, which leads you to thinking your nasal congestion has actually cleared up. It is just a sensation however; menthol has no real effect on clearing nasal congestion.\n\nI'm afraid I don't know the particulars of why menthol triggers these receptors.\n\nSources: 3rd year physiology student / [Source 1 (Peer reviewed)](_URL_0_) / [Source 2 (Wikipedia)](_URL_1_)"
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1gw28y | how to become a good photographer | I realize that like anything it takes practice, but how do you really start to improve? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1gw28y/eli5_how_to_become_a_good_photographer/ | {
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"Mind like a camera, eyes like a lens.",
"1. try to be deliberate about your photography - instead of just walking around looking for something neat to take a picture of, try to think ahead of time what you want to say or capture with your photograph, and then execute on those ideas\n\n2. practice, practice, practice - following rule 1, analyze your photographs and think about whether and why you succeeded or failed to say or capture what you intended - then use this feedback to guide your approach. And practice does not just mean walk around and snap as many photos as possible - in fact do just the opposite - try to take just one good picture per day, but focus on the ideas and the process going into making that one picture - that is the part that needs the most practice - it can take years to develop your artistic sense\n\n3. look at good photography ! Go to the library once in a while and look at the work of the greats - try to think about what you like or don't like and why, and use it to guide your own approach\n\nI might also add, don't just use the internet - there is too much bad photography on sites like flickr, etc., and the \"popularity contest\" ranking methods are rarely the best way to find true artistic quality. It's also dangerous to solicit feedback on the internet - anonymous feedback is generally useless. Try to get feedback from people who you respect as artists, whose work you aspire to equal in quality - or even forget feedback altogether and just do your own thing, live up to your own expectations !\n\n"
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1g74o8 | how does a computer tell the difference between a 1 and 0 in a sequence? | What I mean by this is because a 0 is represented by no voltage, how does the computer tell the difference between 101 and 11 when both have 2 ones? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1g74o8/how_does_a_computer_tell_the_difference_between_a/ | {
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"Computers don't look at \"101\" or \"11\" as single entities. They either look at each individual bit one after the other, or at groups of bits, with each bit being routed to a different transistor.\n\nWhen looking at bits in sequence, things are coordinated using a clock signal. \"101\" would be read in three clock ticks, while \"11\" would be read in two clock ticks. It's pretty easy to tell the different in that case.\n\nWhen looking at all of the bits at once, the computer generally looks at them in blocks of 8, 16, 32, or 64 bits at a time. In this case, the computer would treat \"101\" as \"00000101\" and \"11\" as \"00000011\". Each bit would be routed to a specific transistor based on its position. So in the case of \"00000011\" the first and second transistors would see a high voltage, and the rest would see a low voltage. In the case of \"00000101\", the first and third transistors would see a high voltage, and the rest would see a low voltage\n\nOf course, things are much more complex than that, but the basic idea is the same.",
"Different parts of the computer use different mechanisms for storing or transferring a bit. Generally it's not \"voltage or no voltage\" it's either \"high or low\", or it's \"positive and negative\" depending on the mechanism. This is to help prevent the confusion you are worried about. Trying to measure 0 as \"the absence of everything\" is difficult because noise will often cause non-0 readings. There is a second problem though, and that is it's still hard to tell 1111111 from 11111111. Many systems (RAM, Hard Drives) have physically distinct regions, and that's how they tell one bit from the next one, but for ones that don't they rely on a shared clock. The current state is checked at set intervals that are long enough that you can finish the transition between the two states before the next clock tick. Many systems use this shared clock mechanism. When you buy a computer, the cpu speed (3.2 GHz for example) that is displayed is actually the speed of the internal clock in the computer. Faster is generally better because the faster the clock speed, the more frequently an instruction is run."
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5wdgqe | how do animals know not to look at a solar eclipse? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5wdgqe/eli5_how_do_animals_know_not_to_look_at_a_solar/ | {
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"as far as i know; its a non issue. Its not that they know not to look at it, its that they wouldnt really be looking at it anyway. What use does a wolf have for stargazing? they just know how bright it is. \n\n",
"They don't really know that. However, animals don't have nearly the intellectual capacity of humans, and they just aren't that fascinated by odd-looking things in the sky, so they don't stare.",
"To start with, there is nothing more dangerous about a solar eclipse than just looking at the sun normally. Animals know not to look at the sun, therefore a solar eclipse is not concern for them. They just want look at it.\n\nHumans are told not to look directly at a solar eclipse because looking at the sun is dangerous, and we find a solar eclipse interesting, so people want to look at it."
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27yans | I have heard before that the President used to be very accessible to the public, citizens could just walk up to the White House and knock and request to speak with the president. How truthful is this? | And what kinds of reasons did people go speak to the president about? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/27yans/i_have_heard_before_that_the_president_used_to_be/ | {
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"Not sure about access during the White House years, but in Chernow's bio of Washington and Gordon-Reade's book on Jefferson and Sally Hemmings, both ex-Presidents complained about the cost of unplanned visitors to Mount Vernon and Monticello. Apparently it was perfectly fine for a complete stranger to show up at an ex-President's home, totally unnanounced and uninvited, and expect the ex-POTUS to feed, lodge, and entertain them at no cost, as well as their horse(s). Often there would be several of these uninvited people at the same time. After years of service to the nation, Washington had looked forward to spending quality quiet time with Martha, and lamented the fact that night after night he was forced to make small talk with total strangers. Washington could absorb the costs of entertaining these strangers, but the situation greatly contributed to Jefferson being destitute at the end of his life. ",
"I'm not a historian, but I recently read *[Destiny of the Republic: A Tale of Madness, Medicine and the Murder of a President](_URL_0_)* by Candice Millard. In the book. Millard talks about how Garfield's assassin, Charles Guiteau, would visit the White House every day planning to sit and meet with Garfield to discuss a position within the cabinet. He got at least one face-to-face meeting. The White House also held receptions open to anyone that wished to attend. I'd have to sift through the entire book to find specific mention of what you asked for, but in any case visitors were screened by the President's private secretary Joseph Stanley Brown and either got to sit with the President or not.\n\nIt's pretty wild to consider but at that time, even though Lincoln had been assassinated only 16 years earlier, the general attitude was that because the American population had the power to choose the President there was little cause for angry rebellion. It was also general consensus that even if he was at a higher risk than the average person, nothing could be done about it anyway.\n\nEdit: OK I found something. Garfield held calling hours of 10:30 a.m. to 1:30 p.m. and the White House typically had long lines of people seeking office or audience with him. It's probably mentioned in the book that Presidents were always very accessible, but I haven't found it yet.",
"Lincoln was well known to open the doors and allow lines of citizens and office seekers throughout the halls of the white house. This was in the local newspaper *It is one of the tribulations which must greatly add to the fatigues of office at his juncture, that our amiable President has to give so much of his time and attention to persons who apparently having no business of their own, expend a large degree of their surplus energy in benevolently minding the business of the President.*\n\nAnd William Stoddard is quoted as saying *It is hard work for the President, but he receives and dismisses these varied hundreds of people with wonderful dexterity, the trained result of his natural tact and wit and long practice.*",
"In the prologue of \"The Rise of Theodore Roosevelt\" Edmund Morris relates the tale from the new year of 1907 when, as per his tradition, Roosevelt opened the White House to give a new years greeting to any sober and clean citizen who wished to come by. Describing the scene, Morris writes as follows: \"[Roosevelt] stands with tiny feet spraddled, shoulders thrown back, chest and stomach crescent as a peacock, his left thumb comfortably hooked into a vest pocket. For what must be the three thousandth time, his right arm shoots out. 'Dee-LIGHTED!\" Unlike his predecesors, Theodore Roosevelt does not limply allow himself to be shaken. He seizes on the fingers of every guest and wrings them with surprising power. \"It's a very full and very firm grip,\" warns one newspaper, \"that might bring a woman to her knees if she wore her rings on her right hand.\" The grip is accompanied by a discreet, but irresistible sideways pull, the the President, when he lets go, wishes to have his guest already well out of the way. Yet this lightening moment of contact is enough for him to transmit the full voltage of his charm.\"\n\nSo, at least in Theodore Roosevelt's time, while a citizen could not necessarily spontaneously visit the White House, it was opened for special occasions. And, given Roosevelt's gregarious nature, there would be a good chance of a short conversation with him. Ask him about his Roughriders and he would probably talk your ear off. The day which Edmund Morris is describing is actually additionally remarkable because Theodore Roosevelt set a long standing record for most hands shaken by one man in a day. ",
" > [Lincoln] saw the men ahead. There was no way to avoid them. The guards could not seem to keep them out, and many of them slept in the White House hall. The word had passed that he was coming, so they were on their feet and smiling. Each of these wanted a favor. As he passed, hardly pausing, they asked for jobs or passes to Richmond or the commutation of a military sentence or presidential approval of an illegal business deal. In four years of living in the White House, Mr. Lincoln had become accustomed to the morning vultures. He could do little to be rid of them, and had no desire to help them because, if their claims were just, they would have satisfaction at the proper agency.\n\nThis arresting passage is from The Day That Lincoln Was Shot, the popular history book by Jim Bishop. Describes what happened when the president stepped out into the hall from his White House bedroom on the morning he was assassinated.",
"I love the story about the [1829 inaguration of Andrew Jackson](_URL_0_). The open reception at the White House turned into a drunken brawl. The president had to escape through a window. \n\n"
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4gldbh | What was your PH.D. Thesis and how did you decide to do that subject in particular? | I'm planning on getting my Doctorate so I can become a history professor. I'm not at the point where I need to start on my thesis but I've been trying to think of what I would want to do it on when the time arises. Any advice is welcome!
Edit: This turned into more of an advice column than I had originally intended. I actually do want to hear the subjects that people have researched. I know I have a looooooong time before I need to worry about choosing my own thesis, but the advice so far has been very helpful. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4gldbh/what_was_your_phd_thesis_and_how_did_you_decide/ | {
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"Did you have to write an undergraduate thesis? I'm not getting a doctorate but when I finished my degree I had to do an undergraduate thesis.",
"You're still a freshman so if I were you I'd focus more on taking a bunch of courses and figuring what areas you'd like to study more in depth, what methodologies and ontologies you identify with, etc. \n\n\n\n\nThe way thesis topics come about is often something like. Youre studying broadly, and you figure out what you want to study more closely. Then youre studying one particular area more and you realize you're interested in one area specifically, perhaps one that your favourite prof studies. Then you realize one side or point of view hasn't been explored that much, then you have your thesis. \n\n\n\n\nFor example, I just finished my Undergrad in Politics. I took broad based courses to start, and found myself gravitating to canadian constitutional issues and federalism and theories of rights. Then I took a course on the Charter of Rights and Freedoms with my favourite prof. Then I realized there werent any studies comparing court's dispositions towards privacy rights pre and post 9/11. That then became what I wanted to write my thesis on. It's a fairly fluid process that arises, atleast in my case. \n\n",
"I asked my tutors this question when I was in my final year of undergrad. Their response was pretty much universal: pick a topic you enjoyed studying.\n\nOne in particular said, \"Think back on the papers you've done, and which ones you got good marks in and enjoyed the most.\" For me, that was a paper on the Long Civil Rights Movement, which transformed into my Honours dissertation. \n\nThe reason for choosing something that you enjoy is that you're committing yourself to this topic for a period of time. At Honours and Masters level, it's usually a one year committment to researching a large project on one topic. You need to be interested so that you can maintain a will to work.\n\nFor a PhD, it's 3 or more years, and it's even more important that you maintain the passion. I'd say that for a PhD, you'll have an easier time choosing after you've completed up to MA level, but I could be wrong.",
"If you're asking this question...you're not ready yet. You don't decide on the subject in particular. It decides on you.",
"It's great that you have interest in history and you are already interested in grad research. That being said...keep an open mind because things can change as you go through your Bachelor's. \n\nI double-majored in History and Political Science in my BA. Wanted to do my PhD in the same area. Currently doing my PhD in music, very different field! I eventually realised (over the course of about ten years) that the creative arts was what I gravitated towards, while History is just something I'm interested in. \n\nI encourage you to think about topics that you're interested in, and if doing a PhD will help you expand your knowledge. Also look at the reasons why you want to do a PhD in the first place. Doing one is a hard slog - it's at least three years - and it can be an emotional rollercoaster. ",
"I did my MA a few years ago and decided not to go on to a PhD, but did write both an undergrad and MA thesis. \n\nIn undergrad I focused largely on East and Southeast Asian history, took Mandarin for my foreign language, etc. I ended up writing a brief history of the rise and fall of the Khmer Rouge for that thesis. I'd done a shorter research paper on Tiger Force for a Vietnam War course and kind of branched out from there into the \"really nasty stuff\" field, as my advisor called it. \n\nWhen I started my MA I switched from Chinese to US history (tbh I decided I was way too lazy to have to do my research in Mandarin). I focused mostly on 19th and 20th century American cultural history, with a focus on Chinese immigrant culture. Ended up writing my thesis on the films of Bruce Lee, and the impact the whole Kung fu craze had on Chinese American identity.\n\nLike others have said, if you do end up going on to grad school, you'll find your focus. Probably by the time you're a senior, you'll have an idea of what broad field of history you're most interested in. As you go on in school, you'll focus down sharper and sharper till there's something you've just gotta write about. \n\nOne piece of advice - don't go into debt for a PhD in history. Work hard, write that thesis even if it's optional for your undergrad program, and be open minded about what grad schools you apply to. Go somewhere that will offer you an assistantship or other aid. The job market isn't great for academics right now. It could pick up in the 10 or so years before you'd be looking for a job, but I have so many friends from grad school who're adjuncting now.",
"I'm only completing my MA, which technically isn't even in history (its an interdisciplinary program that includes history though), but I'll give my view. My topic is about Soviet nationality policy in Abkhazia and how it led to discontent with Georgia. \n\nWhen I was applying for schools, I didn't fully have an idea of what to write about; I vaguely thought of something relating to interwar Poland and nationalism there, and with Euromaidan in Ukraine occurring at that time it was somewhat relevant, plus I have ancestry from the region. \n\nThen I went and taught English in Georgia for a few months, and gained a real appreciation for the country. I also found that there is not a lot of material on the country, in English at least, and this piqued my interest. So when I got back to Canada and entered school, I decided to switch from Central Europe to Georgia.\n\nFinding a specific topic on the country proved even harder. All my first year I had no real idea aside from wanting to examine something related to the 2008 war. I felt looking at it from a national viewpoint was logical, as the Abkhaz and Ossetians are distinct from the Georgians, and it slowly led me to considering the Soviet era. It was further parsed down into a specific region, Abkhazia, and era, 1917-1953, due to factors relating to the topic, and the choice to look at it from that angle was established.\n\nThis was also a pragmatic choice on my end. There are quite a few scholars who deal with that era and region of Europe, and thus it was hard to fit in and/or gain notability. On the contrary, there are perhaps 5 names that are worth looking at when dealing with Georgia, so its a lot easier to become a recognised authority on the country.\n\nSo really, I found something I was interested in, and worked from there until a viable topic emerged; if I were to tell myself back when I started nearly two years ago that I'd be writing about this specific topic, I'd honestly be totally surprised at it, as it was not at all what I had in mind at the time. Something will jump out that you find worth looking into, and then the rest will sort itself out.",
"I'm a Ph.D. student in chemistry so I don't have any authority in history but my advice to any aspiring graduate student is choose an advisor who you can work with. Do not choose someone just because they are famous. You need to work with them for years, choose someone that is not toxic. In the end, no one really cares where you get your PhD from, it is the papers you publish that matter.",
"I'm still completing my PhD dissertation, but it's on, I suppose, the inter-dynamics between (amongst? amidst?) Eisenhower, Dulles (JFD), and Nixon, and the administration's Third World policies. \n\nI don't want to spoil it because obviously this puppy is going to be published, reviewed marvellously, make me ludicrous amounts of money, and establish my place among the greats in the field (end sarcasm now)....\n\nBut I'm \"using\" Nixon to show that Eisenhower's bungling of Third World issues was not so much due to misunderstandings, misaligned priorities, or most of the other more common explanations, but because Eisenhower simply did not think the added expense, risk, and effort were worth it. In a connected vein, I'm also showing how Nixon, Dulles, and Eisenhower all viewed the Third World in often drastically different fashions, and how the dynamics amongst the three influenced their arguments and advice. One example - Nixon became increasingly frustrated with his position under Eisenhower and Dulles viz foreign policy, and in the later years ('57, '58) started both openly and privately criticising the administration while making impractical but bold arguments and suggestions for policy changes.\n\nAs for advice, a thesis/dissertation is an astounding investment of work, time, and money/potential money. I'll only offer two short bits of advice. \n\nFirst, unless you are madly deeply and wholly devoted to History, do not pursue a doctorate in History. I say this with the utmost respect and loyalty to the skills, attributes, and lessons involved historical studies impart on a hard working individual. There are simply too many very tangible downsides and sacrifices you will need to make in order to succeed for it to be worth your time unless it truly is your \"calling.\"\n\nMy second bit of advice, coming from someone who thought they were going to write an MA thesis on one topic, then shifted gears radically and wrote on a wholly different topic, now writing a doctoral dissertation on a related topic, is rather simple. Choose something you're incredibly passionate about. Not something you're interested in, interests come and go. Choose something you're willing to be told you are wrong about and willing to argue with someone more experienced and \"smarter\" than yourself on. I originally planned to write an MA on the historical distortions which led to the extremely exaggerated caricature of Caligula both in ancient and more modern texts. However, I soon learned that my ancient Greek and my Latin were simply not strong enough to dance with let alone contend with my elders. Added to that, I found it really interesting, but I simply was not passionate enough to put in the effort needed to get my languages to a strong point and risk the ridicule.\n\nBasically, only try for a PhD if you absolutely love History and can't imagine doing anything else, not are afraid of doing anything else. A PhD is not something most people can achieve, I've seen smart people, hard working people, all kinds of good people fail trying. There is a great deal of life between entering university and leaving with a PhD.\n\nFinally, don't write about Richard Nixon, Dwight Eisenhower, John Foster Dulles, and the Eisenhower administration's Third World/Global South policies, that's mine, I called it, you can't have it. \n\nGood luck!",
"Just a note, but PhD theses are also quite unique, so the question also calls on people to reveal their IRL identities, which some may not be comfortable with. ",
"Be open to whatever directions your interests take you, and cultivate relationships with mentors and peers because those will last and can get you a very long way. I ended up in South Africa, shaped mostly by what I encountered here and the questions nobody seemed to be able to answer in detail about changes in the legal and physical landscapes, and how mapped knowledge came to be. So in a way, my actual topic didn't filter out until after I'd been in graduate school for nine years. The resulting product landed me an incredible position, though, so be aware that even when you get into a PhD program, you won't be locked into a topic--and don't feel that you must race through (but I wouldn't advise taking as long as I did). Our mentors, our colleagues, and our own changing interests and knowledge all dictate shifts. I had a great undergrad mentor who worked on British India, so I went to British Empire, and in graduate school I got sucked into the orbit of Africanists and SA in particular. Experience and exchange will shape your interests to a degree, and part of the fun (yes, it can be fun) is going through that process.\n\nI will leave aside the standard \"make sure you have a plan B, because unless you're starting out at an elite school, your chances are slim to none of making it to the professoriate\" speech for some other day, but always be aware of that too. My advisees get that speech early and often, and you can find it in many archived threads about the profession. Good luck!",
"I have mentioned my PhD topic several times in this sub but do not want to go into more detail than it being about the Nazi occupation of Serbia in WWII for a variety of reasons.\n\nAnyways, the way I arrived at this subject was two fold: One was that I learned the language at uni. During undergrad we were required to take language classes. I was set on an Eastern European language since in the study of the Holocaust no more than ever Eastern European languages become more and more important. Since Russian classes were over full, I decided on Serbo-Croatian since South Eastern Europe has a close connection to my homeland and I suspected that there was little research done into the subject of the Holocaust in the Balkans.\n\nThe second reason was that it turned out I was right on my hunch concerning research. There indeed is little research out there. Having picked up a passion for the area from learning the language and having come to the conclusion that an impact can be made by researching the Holocaust and German occupation in the Balkans, I decided to pursue this over the next couple of years. My intial focus was forced labor policy but I decided to expand after a. I realized the volume of sources and b. somebody else snatched that topic away from me."
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1196x6 | the work of the 2012 nobel prize in chemistry winners. | Link to article: _URL_0_
Thanks! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1196x6/eli5_the_work_of_the_2012_nobel_prize_in/ | {
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"I'll take a crack at it, but I'm by no means an expert. I work in a structural biology lab that focuses on crystallizing of RNA so I'm familiar with the crystallization process. This article focuses on protein crystallization and there are probably thousands of labs around the world crystallizing proteins.\n\nThe first thing to note is the importance of G-Protein Coupled Receptors (GCPRs). The article does a very good job of explaining why they are important in our bodies. Even the most basic Physiology classes will touch on GCPRs. As described in the article, they are a big target for drug design because of the roles they play.\n\nThe next thing to discuss is why crystallization is such a powerful tool. First you have to obtain a diffraction quality crystal. Next you shoot a bunch of X-rays at it. The computer collects the data from the x-rays and compiles them and spits out an image. The end result of crystallization is the atomic structure of the molecule. You can literally \"see\" how the molecule fits together in a 3-D space and the ins and outs of it. \n\nSo what took so long? The article talks about how the GCPR is unstable when you pluck it out of the cell membrane, and it is extremely difficult to stabilize it unless you have the correct combination of \"mystery\" molecules. This quote describes it perfectly:\n\n\"The breakthrough became possible because of detailed manipulation, trial and error and sheer persistence (a trait shared by many protein crystallographers). Crystallography is still very much of an art and there isn’t always a rational path to crystallizing a particular protein.\" \n\nThink about taking a fish out of water. This is a very special fish and it will only survive in a certain fishbowl with certain plants and very special food. The problem is you have thousands of fishbowls, plants, and food and only one or two combinations will work. There is no magical way to find the correct combination either, you have try everything one by one, a process I'm very familiar with.\n\nIn the end, they found a combination that worked for them and it has worked for other labs too. So now that we can see these proteins, we can find out how they interact with their environment and develop specialized drugs for them. "
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dsmykb | What happened to people studying at a university when the world wars broke out? I can't imagine they kept studying, in Europe at least. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/dsmykb/what_happened_to_people_studying_at_a_university/ | {
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"In the United States during the Second World War, college life generally went on as it had before, except that campuses were now almost completely devoid of male students, and many colleges cooperated with the military and/or redirected some or all of their efforts to the successful prosecution of the war. I will focus on the Army's role in the colleges.\n\nThere was no explicit Selective Service deferment for education besides a provision in the original bill which had deferred students until 1 July 1941. Deferments for education were offered only in very limited circumstances, shoehorned into the class for occupational deferments (i.e., degrees for professions that could contribute to the national health, safety, or interest, and/or have direct military applications, such as mathematics, physics, the engineering disciplines, medicine, geography, geology, and the like). The first thing one would notice on campuses would be an ever-increasing rate of absence of able-bodied male students. Colleges that had wide curriculums, such as engineering and the sciences along with the liberal arts, fared better than small private colleges, but all institutions felt the war. In the spring of 1942, the enrollment at the University of Minnesota was down twelve percent from one year earlier, the University of Chicago and the University of Texas were down fifteen percent, and the University of California, Berkeley was down eighteen percent. Liberal arts colleges, especially small private or religiously-affiliated ones, suffered more severely; Blackburn College in Illinois, a private college affiliated with the Presbyterian Church, had 308 students during the 1939-1940 academic year, of which fifty-five percent were men. In the spring of 1944, it had only seventeen male students. The institution survived the war. \n\nLaw schools and law departments suffered more serious declines than schools of other disciplines: \n\n > Law schools suffered sharp declines in enrollment and more quickly than other fields of study. Harvard law school, which had a prewar enrollment of about 1,400, had 600 students in the spring of 1942. Compared with a year earlier, law school enrollments that spring were down 67 percent at Duke [North Carolina], 40 percent at the University of Minnesota, and 27 percent at the University of Pittsburgh [Pennsylvania]. Enrollment in...law schools in New York State was down 71 percent in October 1942 compared with October 1937. When all but two faculty members in the school of law at Santa Clara University [California] departed for war service, its law school closed for the duration.\n\nEven small colleges that offered the sciences or engineering, like Rose Polytechnic Institute in Indiana, still came close to folding for want of students:\n\n > Rose Polytechnic Institute...had an enrollment of 325 in the autumn of 1941, near an all-time high and, considering its prominence in engineering, it was expected to face less drastic enrollment decline. However, by the summer of 1943, when 250 ASTP engineering students arrived, civilian enrollment had dropped to 141. Then, in the spring of 1944 when all ASTP students had departed, Rose was left with a skeleton student body composed of 4-Fs, 17-year-old civilians, and a few older students. Rose had only 70 civilian students when 88 Air Corps ASTRP students arrived in June 1944; they remained until December 1944. In the spring of 1945, Rose had fewer than 40 students, but the end of the war was in sight and the institute survived.\n\nColleges also liberalized admission standards and accelerated curricula, to allow male students and prospective students whom they assumed would be shortly drafted, as well as female students who wished to participate in the war effort, to receive an education. Many schools switched from a semester to a trimester calendar. The University of Michigan accelerated their calendar so that students could complete a bachelor's degree in three years, and Yale University (Connecticut) and Indiana University offered classes six days a week so students could complete a degree in two and two-thirds years. In the spring of 1942, 102 of 178 surveyed colleges had moved commencement ahead from one to five weeks to allow male students who they presumed would be caught in the draft that summer to graduate in time. The University of South Dakota shortened the spring semester by two weeks, cancelled spring vacation, and moved commencement up. The University of Kansas voted to award retroactive credits and degrees to men who left for military service before they completed their last year. The University of Evansville (Indiana) admitted high school students in the top one-third of their classes who had earned at least fourteen credits, and Purdue University (Indiana) required only twelve credits. This was possible because there was a much larger percentage of seventeen-year-old high school graduates and college freshmen in the U.S. in the 1940s than today, because of the fact that many states (twenty percent) at the time required only eleven years of total schooling to result in a high school diploma, rather than twelve as is universally the case today.\n\nThe Army Reserve Officers' Training Corps, established in 1916 as a means to train and commission reserve officers at civilian colleges in the time it would take to earn a four-year degree, also affected the landscape of the wartime college campus. In the spring of 1942, the summer camp between the third and fourth years of instruction which constituted a form of basic military training was suspended for the duration of the war. In 1942, ROTC students constituted a deferred class, and they remained in college. When the Enlisted Reserve Corps program was terminated in the fall of 1942 (see below), ROTC cadets were also affected. It was concluded that officer candidate schools, opened for all arms in July 1941, had proven a more efficient method of producing officers under wartime conditions (seventeen weeks versus four years). The acceptance of any more advanced contracts (the last two years of a college education, leading directly to a commission and service obligation) was suspended for the duration of the war in spring 1943, and ROTC cadets were called to active duty after the detachment of the Army Specialized Training Program at their school was established (also see below) and sent either to basic training or directly to officer candidate school, depending upon how far along in their military studies they were."
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1huz4a | How did people like Khruschev survive through all of Stalin's purges? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1huz4a/how_did_people_like_khruschev_survive_through_all/ | {
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"The purging was, for the most part, almost arbitrary. It wasn't a case that ambitious people necessarily got purged, or subversive people necessarily got purged, or completely loyal people escaped (or got purged). Who got purged and who didn't was almost completely unrelated to any particular variable about a person. \n\n(There are a few counter-examples to this where entire classes of people were purged, but since Khrushchev wasn't a [kulak](_URL_0_) I assume you're not asking about that.)\n\nThis is one of the things that makes it so disturbing: there was no \"correct way\" to be, no \"safe path.\" In Nazi Germany, for example, the dynamics of who got locked up was quite codified — if you weren't one of the \"undesirables\" and you did what was asked of you and you didn't speak up, you were pretty safe most of the time. In Stalinist USSR, nobody was safe, from the very top of the political hierarchy to the very bottom of society. Even the state security people who picked people out for the Gulag would, in many cases, find themselves in the Gulag eventually.\n\nWhy was this the case? Saying \"Stalin was paranoid\" doesn't really cut the mustard as an historical explanation, because Stalin himself, though he was more hands-on with the stuff than a lot of dictators have been in the past, wasn't really making _all_ of these decisions. The general answer that I've seen is that basically the Gulag purges were just yet another example of Soviet production planning, like agricultural output or steel development. The security agencies were expected to meet quotas in rooting out \"wreckers\" and \"subversives\" and so on, and so they did. They'd pick up someone, get them to name their friends as possible accomplices, pick up those people, and so on. If they showed themselves to be too un-zealous in this activity, they themselves could end up on the chopping block. \n\nAgain, to me this highlights what makes the Soviet Union so disturbing, and so much different than, again, Nazi Germany, the one place it is often compared to. The USSR under Stalin was the real \"banality of evil,\" it was a society based on brutally enforced unreasonable expectations, where ideology mattered _a bit_ to be sure, but the sheer inertia of its political apparatus mattered quite a lot more. Ideology doesn't make you purge people _at random_, that's a different sort of political dysfunction.\n\nTo come back to Khrushchev: I don't think one can say a whole lot more than \"he got lucky.\" Even if he did employ specific strategies, you can find examples of others who employed _exactly_ the same strategies and _still_ got purged. Being loyal, being good at your job, being a good soldier, having good connections — _none_ of these things could save you if your number came up.\n\nSuggestion: Solzhenitsyn's _Gulag Archipelago_ is a wonderful, chilling, amazing read. It's not just that he's a great writer and had a witty tongue, but the book does an amazing job of recreating for you the arbitrariness of the entire enterprise, taken from Solzhenitsyn's own years inside the Gulag, talking with other prisoners, guards, and so on.",
"According to Khrushchev, in his autobiography he attributed some of this to quick thinking. Obviously, an autobiography should be taken with a grain of salt, but he went into a good deal of detail involving one meeting of the Politburo during the height of the purges.\n\nThe atmosphere at the time was so dangerous that simply having someone stand up and make an accusation against you without evidence was enough.\n\nA woman stood up in front of the assembled Politburo and accused him of being an enemy of the state. A hush fell over all those assembled. He kept to his feet and demanded to know how she arrived at that conclusion. She said that she could just tell. At that moment, according to his autobiography, he knew he was dead if he didn't diffuse the situation immediately. So, he quickly accused her of being a prostitute saying to her that he can tell one when he sees one. Afterwards, everyone laughed and the tension was gone.\n\nHe credited his reaction with saving his life, believing that if he had become defensive and tried to deny it rather than throw another wild accusation back at her, that he would have been doomed.",
"Two points\n\n* If anyone is under the impression that Khrushchev might have been under suspicion during the Purges due to attitudes he expressed after 1953, think again. Prior to that Khrushchev was far from liberal/reformist. Khrushchev oversaw repression (arrests, deportations etc.) in the Ukraine for example. Khrushchev was the king of bull headed leader Stalin liked, and when Stalin sent someone as a 'troubleshooter', Khrushchev was one of the guys he could send.\n\n* Khrushchev in the early years had the patronage of Stalin allies like Lazar Kaganovich, so Khrushchev was relatively safe. Which is somewhat amusing as Kaganovich ended up Khrushchev's enemy after his turn against Stalin in the 1950s.\n\nAlmost forgot to reference a source. A nice accessible one is William Taubman's biography - Khrushchev: The Man, His Era."
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fwpjif | when and where did christian masses was created? how were they celebrated? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/fwpjif/when_and_where_did_christian_masses_was_created/ | {
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"The Christian mass developed out of the Love Feasts mentioned in the New Testament in verses such as 1 Corinthians 11:20–11:34 and 2 Peter 2:13–2:13.\n\n\nWe're lucky because these love feasts show up on a few early Christian frescos so we actually know what they looked like and how they were ordered. [Here's a good index of those feasts](_URL_0_).\n\nThese feasts, as best as we can tell, appear to be a reenactment of sorts of the Last Supper. They started with the breaking of bread, and concluded with the sharing of wine. It was all rather informal.\n\nIt must be emphasized that at this early phase of Christianity, The Love Feast was **not** a form of worship necessarily. These people were still Jews. They still gathered on Saturday to worship. On Sunday they would then gather to ponder Christ together. This difference is actually also offhandedly mentioned in the scriptures as well, in Acts 20:6-7:\n\n > And after the Feast of Unleavened Bread, we sailed from Philippi, and five days later we rejoined them in Troas, where we stayed seven days. On the first day of the week we came together to break bread. Since Paul was ready to leave the next day, he talked to them and kept on speaking until midnight.\n\nYou see here that the Early Christians were not divorced from the regular Jewish worship schedule. Sundays was not a form of worship. It was a gathering to discuss and debate about Jesus' teachings around a meal, the day after worship. This might be because they viewed this as a work and so didn't want to do it on a Sabbath.\n\nYou once again see a prototype of the Christian Mass in 1 Corinthians 16:1-2, when along with the above, donations start to be given to the church on the first day of the week:\n\n > Now about the collection for the Lord’s people: Do what I told the Galatian churches to do. On the first day of every week, each one of you should set aside a sum of money in keeping with your income, saving it up, so that when I come no collections will have to be made.\n\n\nFrom this we can get a sense that Sunday was increasingly the day Christians would gather around a dinner meal to discuss Jesus and manage their communal finances, and Saturday was the day they rested and went to temple to worship.\n\nWhat happens to evolve these elements into a unified service is a bit unknown, but by the time of Origen in the early 3rd century, this informal gathering of food and debate and financials was formalized into several liturgies, and functioned as a kind of day-long worship service on Sunday. Origen makes mention of a few of these formalized practices but it's also clear they have remained mostly disorganized and are merely individual practices that occur throughout the day rather than at a single hour-long church service. I'll post a few passages of his liturgical musings that show some resemblance to what Christians do today but at this time were more informal.\n\n > There are things among the Church's observances, which everyone is obliged to do, and yet not everyone understands the reason for them; e.g.,... the fact that we kneel to pray, and that of all the quarters of the heavens, the east is the one we turn to when we pray... And can you readily explain the reason for the way we receive the Eucharist, for the rites it is celebrated with or for the words, gestures, commands, questions and answers made in Baptism?\n\n...\n\n > There is no limit to the number of postures the body can take up, but the position to be preferred is unquestionably the one we adopt when we stretch out our hands and lift up our eyes, as it is the best bodily expression of the soul's attitude in prayer.\n\n...\n\n > I say that this should be observed when there are no obstacles. But circumstances may sometimes lead you to pray sitting down, e.g., if you have... bad feet; and if you have a temperature, you may even have to lie down... for if your business makes it impossible for you to go to some quiet place to discharge your debt of prayer, you will not be able to insist on standing when you pray.\n\n...\n\nAnd here, we see the first inclanations of the idea of a church **building**. Origen is laying the foundations of what will eventually be the argument for gathering in a specialized space dedicated to prayer just like the temple of the Jews:\n\n > As far as place is concerned... any place will become suitable for prayer if you pray well in it... How-ever, if you want to say your prayers in greater quiet and without so much distraction, you may choose a special place in your own house, if you can have a consecrated place, so to speak, and pray there.... Special grace and benefit are to be had from the place of prayer, the place, I mean, where the faithful assemble; for it is reasonable to suppose that angelic powers are present when the faithful meet together; the influence of our Lord and Savior must be there too and so must the spirits of the saints - the spirits, to my way of thinking, of the dead who have gone before us and obviously, too, the spirits of those saints who are still alive, though how, it is difficult to say.\n\n[Source for these passages](_URL_1_)\n\nFast forward a mere century or so to St Ambrosia, and we see these articles of Origen have formulated into regional formal liturgies. We know there were regional variations because in writing to St Augustine, St Ambrosia says:\n\n > When I visit Rome, I fast on Saturday; when I am here, I do not fast. On the same principle, do you observe the custom prevailing in whatever Church you come to, if you desire neither to give offense by your conduct, nor to find cause of offense in another's.\n\n[source](_URL_2_)\n\nAmbrosia himself has the formal Catholic Liturgy attached to his name, through we cannot say for certain if he invented some kind of official liturgical worship we today would call the Mass. But we do have stories of what sounds like him inventing the model of the mass we use today to keep refugees focused on pray in times of fear and worry. Henry Jenner writes in the 1913 Catholic Encyclopedia:\n\n > We know from St. Augustine (Confess., IX, vii) and Paulinus the Deacon (Vita S. Ambros., § 13) that St. Ambrose introduced innovations, not indeed into the Mass, but into what would seem to be the Divine Office, at the time of his contest with the Empress Justina for the Portian Basilica (on the site of San Vittore al Corpo), which she claimed for the Arians. St. Ambrose filled the church with Catholics and kept them there night and day until the peril was past. And he arranged Psalms and hymns for them to sing, as St. Augustine says, \"secundum morem orientalium partium ne populus mæroris tædio contabesceret\" (after the manner of the Orientals, lest the people should languish in cheerless monotony); and of this Paulinus the Deacon says: \"Hoc in tempore primum antiphonæ, hymni. et vigiliæ in ecclesiâ Mediolanensi celebrari cœperunt, Cujus celebritatis devotio usque in hodiernum diem non solum in eadem ecclesia verum per omnes pæne Occidentis provincias manet\" (**Now for the first time antiphons, hymns, and vigils began to be part of the observance of the Church in Milan, which devout observance lasts to our day not only in that church but in nearly every province of the West**). From the time of St. Ambrose, whose hymns are well-known and whose liturgical allusions may certainly be explained as referring to a rite which possessed the characteristics of that which is called by his name, until the period of Charlemagne, there is something of a gap in the history of the Milanese Rite, though it is said (Cantù, Milano e il suo territorio, I, 116) that St. Simplician, the successor of St. Ambrose, added much to the Rite and that St. Lazarus (438-451) introduced the three days of the Litanies.\n\n\nSo we can definitvly put the start of the formal mass as we know it today to around the year 400AD.\n\nIt's interesting to note that by and large most of what we would call formal Christian worship can be dated to a few decades prior to the year 400AD. It seems in these decades, the Christians were heavily contesting with the Arians. Ambrosia himself inherited an Arian bishopric. And this is just speculation, but it seems unlikely to me to be mere coincidence that the first time Christmas is officially celebrated on the 25th of December correlates to Arius' death. It appears to me, that the Arians are really what forced Christians to formalize a unified liturgical mass. Why that is I can only speculate. Perhaps the Arians had a more unified Liturgy so the Catholics wanted to mimic that. Or perhaps the liturgy was a means by which to emphasize Catholic Christology and route out Arianism in the worship service.\n\nIn any case, bu the year 400 the mass is more or less in a typical western form that can be called a \"western rite\". I chose to focus on this rite as it's what I'm more familiar with. It's worth noting this didn't get adopted by everyone, and the East had its own distinct litrugy. India, too, developed its own St Thomas liturgy which unfortunately I do not know much about other than it exists. Also, up in Britain a distinct liturgy developed as well and would continue to exist until the Norman conquests. There is an amusing letter by a Bishop who was getting frustrated by this local liturgy which was very different from Rome's. He writes:\n\n > Britones toti mundo contrarii, moribus Romanis inimici, non solum in missa sed in tonsura etiam (Britons are contrary to the whole world, enemies of Roman customs, not only in the Mass but also in regard to the tonsure)\n\nThe author of this was either Saint Aldhelm or Gildas around the 7th century. So we can say for sure that regional variations continued for centuries after the Arian controversy."
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9rsois | The moon is able to redirect the sun's illumination onto the earth. Does the earth also illuminate the moon the same way? With less, or more intensity? | askscience | https://www.reddit.com/r/askscience/comments/9rsois/the_moon_is_able_to_redirect_the_suns/ | {
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"Yes it does. If you can find a place with low enough light pollution, (mostly places away from cities) look at the moon when it is in the crescent phase. You will see the bright crescent illuminated by the sun and you will see the rest of the moon's disc illuminated by reflected earth light. It's faint but unmistakeable.",
"Yes. Think of when the moon is a thin crescent. It is often possible to see the entire moon, because the part not illuminated directly by the sun is receiving reflected illumination from the earth.\n\nAlso, as bright as a full moon appears, the moon's surface has an albedo of .12, which means that only 12% of the incident light is reflected. By contrast, the earth's albedo is very high when there is extensive cloud cover. This means that the illuminate on the moon resulting from reflection from the earth is much higher that reflection from the moon to the earth.",
"If you stand on the Moon the Earth is much larger *and* much brighter per area (it reflects sunlight better than the Moon) than the Moon as seen from Earth. You have phases similar to the Moon as seen from Earth. No one has ever stood on the Moon while it was night there (not counting robots), but the Earth would be very impressive and often so bright that you could easily walk around. It is still clearly visible during the day there.",
"As others have said, yes. You can actually see this effect as \"[Earthshine](_URL_0_)\" during a very thin crescent Moon, when sunlight reflects off Earth, reflects again off the Moon, and then back to Earth.\n\nWhat others have not said, however, is how much. On average, the Moon receives more reflected sunlight from the Earth than the Earth receives from the Moon because 1) The Earth is bigger, and 2) The Moon is surprisingly dark.\n\nWorking out some numbers here: The Earth's radius is 3.66 times larger than the Earth, which means the reflecting area is 3.66^2 = 13.4 times larger. On top of that, the Moon has an average albedo of just 0.12 (about as reflective as old asphalt), while Earth has an average albedo of 0.3 - that means each square meter of Earth reflects 0.3/0.12 = 2.5 times as much sunlight as a square meter of the Moon.\n\nPutting that all together, that means, on average, the Earth as seen from the Moon is 13.4 * 2.5 = 33.5 brighter than the Moon seen from Earth."
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rhe7x | why did einstein say that if we could travel at the speed of light we would be able to time-travel? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/rhe7x/eli5why_did_einstein_say_that_if_we_could_travel/ | {
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"It's referring to time dilation - as your speed approaches the speed of light, time slows down for you.\n\nThis means you can get into a spaceship, travel very fast away from Earth and come back a year later. Thousands of years may have passed. So in this manner, you have travelled into the future. \n\nPutting any physical impossibilities aside, if you get into a spaceship that is so fast it travels at the speed of light, no time will have passed for you at all, but thousands or millions or billions of years can have passed on Earth and you have thus travelled into the future.",
"The explanation I've always liked goes like this: Everything has a set velocity that is divided between space and time. As you move faster through space, you move slower through time, and vice versa. Your speed through space plus your speed through time is always constant, and is the speed of light. Light travels through space so fast that it doesn't have any velocity left to travel through time.\n\nSo, if you're traveling near the speed of light, you're traveling through time incredibly slow compared to everything else. If you traveled in a huge circle, when you returned to your starting point everything there would have gone much further through time than you, and it would appear to you that you jumped into the future.",
"Here's my explanation from [a previous thread](_URL_0_).\n\n\nSay we're meeting at a coffee shop to discuss time dilation. I need coordinates; you propose 59th St and 5th Avenue. The street gives me the north-south coordinate and 5th Avenue gives me the east-west coordinate. There's also another dimension of height, but it would be absurd to find a Starbucks floating in the sky. We're meeting at street level. That takes care of three dimensions.\n\nBut that'll be of no use to me! I'll just be standing stupidly at 59th St and 5th Ave all day! You haven't given me a time. We could be meeting next year for all I know!\n\nThe dimension of time gives us another two directions. There's already up, down, left, right, forwards and backwards. Time adds futureward and pastward.\n\nI'm standing still at 59th and 5th. Even though I can't feel it, all of my energy is being devoted to moving me in the direction of futureward. \n\nThings get interesting when we put this onto a graph. Time is on the x axis and space is on the y axis. \n\nspace\n\n^\n\n|\n\n|\n\n|\n\n------------------ > time\n\n\nMe waiting at 59th St and 5th Ave is (for the purposes of this graph) 0 movement on the space axis (let's disregard the movement of earth and the solar system), so we just have a straight arrow parallel with the time axis.\n\nspace\n\n^\n\n|\n\n|\n\n|------------ > \n\n------------------ > time\n\nOnce I see you waving across the sidewalk, I start moving towards you. Some of my energy, originally totally in the futureward direction, is diverted into moving through space. That straight line gets tilted up slightly from where it intersects the y-axis. \n\nAs I start running faster and faster, the angle gets greater and greater and the line gets tilted further. Less of my energy is being used to travel through time. \n\nHowever, it takes more and more energy for me to approach the speed of light.\n\nLight travels along the y axis. From light's perspective, everything stands still! It's perpendicular to the time axis, so if you were a photon, everything happens simultaneously. As far as you are concerned, you make it from emitted from a computer screen and hit a human's eye instantly. \n\nIf I were to somehow break the speed of light, my arrow would tilt past the y-axis and the x-value (time) would be negative. I would go backwards in time!\n\n \n\n \\ \n\n \\ |\n\n |------------ > \n\n < --O------------------ > time\n\n----------------------------------------------\n\nI hope that clears things up. If you're interested, Brian Greene gives a great analogy of time dilation in the second segment (around 20:00) in this PBS segment: _URL_1_"
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6cps0i | does a soda/coke/fizzy drink contain/weight the same when it goes flat? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6cps0i/eli5_does_a_sodacokefizzy_drink_containweight_the/ | {
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"When the drink has gone flat, it has released carbon dioxide which is dissolved in it.\n\nA can of Coca-Cola has circa 2.2 grams of carbon dioxide in it. If it went perfectly flat, it would weight about this much less than before."
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6834e7 | How much energy is released from 2 Hydrogen - > Helium Fusion reaction? | How much energy is released?
Ex: in the sun or in experimental reactors
When will experimental reactors be sustainable?
But I'm asking for just ONE of these fusion reactions, and a comparison to how much energy one fusion of 2Hy to 1He is.
My curiosity thanks you in advance! | askscience | https://www.reddit.com/r/askscience/comments/6834e7/how_much_energy_is_released_from_2_hydrogen/ | {
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"What isotopes of hydrogen and what isotope of helium? [Here](_URL_0_) is a Q-value calculator for arbitrary nuclear reactions (assuming ground states).",
"The reaction in the sun is actually 4 hydrogen- > helium. The whole thing produces 26.732 mega-electron volts of energy, which is enough to accelerate a proton to 2 km/s. This doesn't include the eventual annihilation of the positrons that are produced, which is another MeV."
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12l8u6 | Pathologically speaking, is it possible for a disease to exist (either bacterial or viral) which discriminates its victims based on race, or sex, or age? | askscience | http://www.reddit.com/r/askscience/comments/12l8u6/pathologically_speaking_is_it_possible_for_a/ | {
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"Such things as Breast Cancer or Testicular Cancer?",
"Sex and Race are more possible, as different racial traits are manifested by slight variations in DNA and a microbe could theoretically attack these specific traits. \nAge I can't see a way that could happen unless the microbe has a prolonged incubation / dormant time, however I can't see a way of selectively activating based on patient's age.",
"For race absolutely. Many African people have a partial immunity from malaria, and the gene that provides this immunity also causes sickle cell if you inherit two. We adapt to our environments, and pathogens adapt to us.",
"Race -- Sickle cell anemia.\n\nAge -- Shingles, SIDS, Heart failure, cancer, basically every disease ever.\n\nSex -- Breast cancer",
"[Kaposi's Sarcoma](_URL_0_) is a tumor caused by a virus that primarily affects Jewish people (specifically Ashkenazi, I think), certain mediterranean people, certain african peoples, and people with weakened immune systems, most famously AIDS patients.",
"There are some infections which are more easily caught by women than men due to anatomy. For example, women get [urinary tract infections](_URL_0_) much more easily than men because the female urethra is shorter. Also, being penetrated (vaginally or anally) carries a greater risk of HIV transmission than being the penetrating partner, so a woman who has sex with an HIV-positive man is more likely to contract HIV herself than a man who has sex with an HIV-positive woman.\n\nBoth of those examples are, of course, diseases that affect both men and women - the difference is quantitative, not absolute.",
"Yes, and many have but not as often now as you would see before.\n\nWhen it came to race absolutely, but the problem is that while many races today still have partial immunity, or have higher chances or certain diseases the chances are small. We would see bigger changes in untouched civilizations which still exist today, and the longer untouched the bigger the changes. This is mainly due to in modern times it's pretty hard to be one race, even people who identify as one race you don't have to track back very far to find different races in their gene pool, and evolutionarily speaking 500 years is not all that long. We are mostly a mix race already, and are begining to increase rapidly towards a true mix today meaning less and less diferences globally. Going back 50,000 years humans in different areas of the world, completely excluded from pretty much other populations were much much more varried than humans are today. A huge factor is that we are more mixed and they were more forced together, in smaller populations, which means more inbreeding, and different cultures at different enviroments can cause many issues such as a genetic bottleneck, being diseases becoming specific to them, and other factors. This can be seen in humans occuring 70,000 years ago.\n\n_URL_0_\n\nWith that being said in a way yes diseases do target sex, age, and race but today for race it is more so partial immunity, partial susceptablity and small percentages of that. For sexs that is easy, does a women have a prostate? Well she can't get prostate cancer, she can't get uterin cancer, but as a guy I can't. Guys and women can get breast cancer but women much more likely.\n\nAge can be a very big factor to. Take chicken pox which is the varicella zoster virus in children it manifests as chicken pox and luckily not be very harmful, but as you age it can very easily be much more severe and fatal and manifest as shingles that cover the body. \n\nYou can also look at aging specific diseases which affect people at differening ages like chicken pox at differening rates. The older you are the more susceptable to disease in general but not always.\n\n_URL_1_\n\nSo it really depends what you mean by discriminates, diseases can't discriminate, however in a way by nature they will only work under certain conditions, meaning temperture, enviroment, race, sex, age, species, etc etc. If that is what you mean by discrimination then every living thing discriminates, as does disease, and they do exist."
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1nz02l | why i like smoking cigarettes. | Especially when I'm drunk. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1nz02l/eli5_why_i_like_smoking_cigarettes/ | {
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"Alcohol and nicotine causes your brain to release dopamine, a hormone that is near the pleasure center of your brain, and controls addiction. When you drink alcohol, you have a heightened dopamine level, in which you are more aware of other addictions. Nicotine in cigarettes creates more of a crave than usual as a result. "
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8sl6s9 | How was the japanese navy able to ambush taffy 3 during the battle of samar ? | In the end of 1944 the us navy was significantly larger, better trained and better equipt. Also they had multiple years of experience in carrier operations and scouting. How was such a large ijn taskforce able to go unnoticed, after already being detected and atacked before, and also find a lone group of usn escort carriers ? What exactly did the usn wrong and the ijn right that day ?
Edit: I woke up to three excelent answers. Thank you very much. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/8sl6s9/how_was_the_japanese_navy_able_to_ambush_taffy_3/ | {
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"The limits of technology available to the USN, and questionable judgment by Halsey, came up against some crafty maneuvering and good luck based on improvisation by the IJN.\n\n\nSimply put Halsey with the big fleet carriers was too far away for strikes or even additional recon to track Center Force later into the afternoon during daylight. The last daylight strikes on the task force which focused on *Musashi* ended around 3:30-4:00 in the afternoon. About the same time that Kuria ordered the main body of Center Force to turn around and at least fall back out of air range.\n\nAny other daylight strikes launched by Halsey would have required landing after dark. This was done on occasion, notably at Philippine Sea, but was always a big risk. Not every pilot was trained up for night landings or navigation, and even for those who were it was a big risk, and drained the pilots. A bold choice when Halsey was still expecting to get word about sighting the remaining IJN carrier any time now and his forces in general were being blitzed by a series off attacks from ground based air, which would cost him the light carrier *Princeton* that afternoon. \n\nThat is not to say he had no night assets at hand, the USN had become rather effective at first using night fighters and strike aircraft with radar to protect the task force, but to start using it in an offensive role from the carriers or at least to scout. The light carrier *Independence* with Halsey carried a small air wing expressly dedicated to these missions and it did launch scouts both towards Kurita, and North towards the now spotted IJN carriers. But this was still an inexact process, and even until the end of the war there were always some chaff and false alarm scouting reports for commanders to have to sift through for actionable ones. But those search flights do turn up at least the possibility that Kurita had turned back around and might be coming through the San Bernardino straight towards the US landing beaches and where the second line fleets were concentrated.\n\nSo we have a threat that seemingly had decided they didn't want to tangle after getting a bloody nose in Kurita, and a new threat of unknown striking power in the carriers that Halsey could steam all night North and be in position for dawn strikes to knock them out early and decisively if all went to plan. So off he goes, fixating on what he saw as the real prize carriers hunting other carriers. He was also only then on the afternoon of the 24th back at full strength, he had previously sent off nearly half his carriers under John McCain Sr. to refit and refuel, but had to recall them when a battle was looming. \n\nBut yes that does open up a large gap in the US forces, though his was not the only force prepared to defend the US anchorage and rear line fleets. Kinkaid had massed his better combatant ships including escorts and his older battleships under Oldendorff to ambush the Southern Force in the shooting gallery of Surigao Straight. Theoretically if on the 25th of October Kurita had turned back those ships could at least get into position to screen the other US supporting units while Halsey got his birds in the air. He had also notified Nimitz of the plan that if he needed to he would detach his newer better fast battleships and some escorts under Willis Lee to cover his old position while he took his carriers North. But while Nimitz and Kinkaid may have assumed, and seem to have done so, Halsey meant this only as a possibility, and never made the decision to do so. Both to keep his direct escort against air attack at max strength, but also to up the chance no IJN carriers escaped by sinking them with gunfire if he had to. \n\nThat gap then is where Kurita slipped Center Force through in the San Bernardino straight where they could then turn South towards their targets and the US second line forces. Hence Nimitz's famous message to Halsey during the height of the action the morning of the 25th demanding that Halsey reply:\n\n > TURKEY TROTS TO WATER GG FROM CINCPAC ACTION COM THIRD FLEET INFO COMINCH CTF SEVENTY-SEVEN X WHERE IS RPT WHERE IS TASK FORCE THIRTY FOUR RR THE WORLD WONDERS.\n\nSo in the end smart seamanship by Kurita, though his and the other forces deathride was ordered so there was to be no retreat anyway(not that the USN was fully aware though) let him drop off USN radar literally for a time. While Halsey's fixation on finding the IJN carriers off Cape Engano and finishing them led him to ignore threats from all other sectors until that was dealt with and his poor communication(and in a sense poor coordination by Nimitz, and nobody on halsey's staff either wanted to contradict their boss or thought the rumblings of Kurita's advance accurate enough to be actionable) meant that Kinkaid and the rest of 7th Fleet had an in accurate understanding of who was guarding their Northern flank where. So at sunrise on the 25th Ziggy Sprauge and his escort carriers thought they had no reason to fear and would continue to support operations ashore and instead met Kurita and his big guns. \n\nYes its taken from Wiki but I rather think this map is very helpful in understanding the positioning of the the USN and IJN forces, notice especially the position of Halsey's carrier groups and his bringing them together to fight Ozawa's Northern Force, opening the door for Kurita. _URL_0_",
"Well the simple answer is poor staff work by Halsey and the 3rd Fleet allowed Kurita to surprise everyone by passing through the San Bernadino strait in darkness.\n\nKurita's force had been hit hard by submarines and aircraft from the Halsey's 3rd fleet on the 23rd and 24th. Losing Musashi, Atago and Maya sunk and Takao & Myoko forced to return to port. Following these attacks Kurita had started sailing away from the strait. This movement was observed by the Americans who assumed that he was retreating. Then after 5pm Kurita turned back around to his original course and passed through the strait in the pre-dawn hours of the 25th.\n\nMeanwhile in the late afternoon of the 24th the Japanese decoy force commanded by Ozawa had been detected well to the north. Halsey pulled in his aircraft and charged north with the aim of eliminating the last Japanese carriers. Preliminary orders were drafted to create a battleship task force (TF34) to guard the exit from the San Bernadino strait but those orders were never executed before Halsey and most of the 3rd Fleet staff went to sleep. And that's where things get murky.\n\nKurita's change of course did not go unnoticed by the Americans. Night time reconnaissance revealed his progress and that information is known to have been relayed to 3rd Fleet. Indeed several senior officers in various sub-groups of 3rd fleet attempted to raise the issue with Halsey's staff but were brushed off and effectively told to mind their own business. To compound matters the commander of 7th Fleet (Kincaid), which was the superior HQ for Taffy 3, assumed that TF34 had in fact been created. If Kincaid had known that it had not been created he would have adjusted his own dispositions accordingly.\n\nPresumably Halsey meant to re-examine his deployments on the 25th and create TF34 if needed. But by dawn on the 25th 3rd Fleet was hundreds of miles to the north^* and Kurita in Yamato was practically within gun range of Taffy 3. The rest is history.\n\nsource : possibly the best book about naval action in WWII, James Hornfischer's *Last Stand of the Tin Can Sailors*\n\n^* Meaning that TF34 would have been useless at that point anyway. If it was to be created at all it needed to be created on the 24th *before* Halsey took his fleet north.",
"With hindsight, the USN did make many crucial errors in failing to provide a carrier group to protect the landings at Leyte, but at the time this wasn't really beyond current naval strategy. Ozawa's forces sailing to the north of Luzon provided a vital strategic target for Halsey, as even though his role allotted to him by Nimitz was to protect MacArthur's landings, both he and Kinkaid felt that the opportunity to destroy Japanese carrier forces was the Third Fleet's 'prime objective'. Combined with the principle of 'concentration of force', Halsey was compelled to sail northward with all four of his carrier task groups, leaving Leyte undefended.\n\nHalsey was, however, well aware that Kurita's force was in the Sibuyan Sea with the clear motive of attacking the landings at Leyte. The force had lost four of its heavy cruisers off Palawan after an attack by USS *Darter* and *Dace* on the 23rd, with two sunk, and the day after had come under a massive US air attack which had sunk the *Musashi*. However, the *Musashi* was able to act as a decoy for the rest of Kurita's force, absorbing the full brunt of air attacks and allowing Kurita to withdraw most of his ships. It was assumed then by Halsey and most officers in the Third Fleet that Kurita had lost more ships than he actually had, and with the force already short on escorts and fuel oil, it seemed logical Kurita would be forced to return West. While Kurita's force was eventually picked up returning to the San Bernardino Strait, US reconaissance was patchy and poorly executed, and eventually called off as Ozawa's aircraft had attacked task force 38.3.\n\nMiscommunication between Kinkaid and Halsey also played a role here, as Kinkaid had wired Halsey on the latter's decision to move three carrier task groups north against Ozawa, to which Halsey had failed to respond. Kinkaid had assumed that Halsey had left his fourth group in defence of San Bernardino. It was similarly assumed by most officers that a battleship group was being sent to San Bernardino, especially those onboard the USS *New Jersey*, who were then surprised the next morning to find the battleships accompanying the carriers on their way north. Kinkaid had also been, however, quick to allay Halsey that Kurita's force had been 'too heavily damaged' to be of any threat, and Halsey himself did not believe that Kurita could undertake a night action, or reach Leyte before nightfall.\n\nHistoriography hasn't been kind to Kurita, and it seems rightly so. His speech to his signals staff on 'miracles' and the 'self-sacrifical' role of Ozawa and Shimi's forces seem his only influence on the Battle off Samar being as close-knit as it was. The decision to return East came largely by command of Toyoda at Combined Fleet HQ, telling him to 'go with God' and 'charge'. His failure to provide adequate destroyer escort and the consequential loss of three cruisers, including his own flagship *Atago,* alongside the lack of air cover provided and the loss of *Musashi* inadvertantly caused the USN to believe Kurita's force too weak to be of any threat to the Leyte landings.\n\nIn sum, the the closeness battle off Samar resulted primarily from US tactical error. The failure of a battle-line being dispatched to San Bernardino, owing to miscommunication and Halsey's own eagerness to engage Ozawa led to Kurita being able to engage the landing force escorts. The battle at Surigao had also diverted Seventh Fleet attention toward Nishimura's force. Japanese tactics, as in Kurita's tactics, had little part to play. It was, for Kurita, pure luck that USN reconaissance aircraft did not pick up his force re-entering the Sibuyan Sea, the running aground of the *Darter* that prevented a re-engagement by submarines, and Halsey's paradoxical decision to leave Taffy 3 without escort.\n\nSource:\n\nH.P. Willmott. *The Battle of Leyte Gulf: The Last Fleet Action*. 2005."
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lmgob | Big Bang: how does evidence for the expansion of galaxies support the claim that space itself is expanding? | Sorry if this is a bit basic or obvious, but it's something I've wondered. If we can observe galaxies growing increasingly distant, it seems like a big bang at least created the galaxies within space. How, though, are we able to extrapolate that the universe—space itself—is expanding? | askscience | http://www.reddit.com/r/askscience/comments/lmgob/big_bang_how_does_evidence_for_the_expansion_of/ | {
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"If things are moving, then relativity tells us we should observe time dilation. Through various astronomical techniques, we can check this... and it turns out that we *don't* observe time dilation in distant galaxies. The problem is that they are Doppler shifted, so we *know* the distance between us is increasing.\n\nHow do you resolve that contradiction? Well, you say that the space between us is expanding. That way distance is increasing, so the Doppler effect can happen. But at the same time, nothing is moving *through* space, so time dilation doesn't happen.",
"Galaxies aren't just moving away. How fast they're moving away from us *increases* as they get further away. And also, importantly, every galaxy is uniformly moving away from us. Take a second to think about that - there's only two real possible explanations for this observation. \n\n* All the galaxies are moving away from us because we are at the center of some sort of cosmic force that threw everything away from us and we're at the center of it. This goes against a lot of principles in cosmology, most notably that the universe is homogeneous and isotropic. That is, that the universe is the same everywhere and in every direction. Saying there exists a \"center\" would make that center point different from everywhere else.\n\nOR \n\n* Space itself is expanding, filling in the gaps everywhere with more distance. \n\nThe numberline analogy has always worked best for me: imagine the universe is a numberline from minus infinity to positive infinity. The Earth is at some arbitrary point, say 42, on this numberline. Every galaxy, the one on 40, the one on 80, the one at -200, are all moving away from us. To assume that every other galaxy is just running away from 42 would be rather vain! A better explanation is that the numberline itself is expanding. Stretching, if you will. Pretend there is a scale factor that the entire numberline is multiplied by. As the universe expands, the scale factor grows. Its like all the numbers on the numberline are getting multiplied by a scalar. So instead of us being at 42 and the other guys at 40, 80, and -200, in the future, when the scale factor is twice what it is now, we will be at 84, the other guys will be at 80, 160, and -400. See how the distances are all bigger? We used to be 2 away from our neighbor, but now we're 4 units away. And the guy at -200.. he used to be 242 units away, now hes 484! It neatly explains why distant objects are receding faster, and does not rely on us being at the center of the universe.\n\nEDITed because I accidentally a word or two.",
"If things are moving, then relativity tells us we should observe time dilation. Through various astronomical techniques, we can check this... and it turns out that we *don't* observe time dilation in distant galaxies. The problem is that they are Doppler shifted, so we *know* the distance between us is increasing.\n\nHow do you resolve that contradiction? Well, you say that the space between us is expanding. That way distance is increasing, so the Doppler effect can happen. But at the same time, nothing is moving *through* space, so time dilation doesn't happen.",
"Galaxies aren't just moving away. How fast they're moving away from us *increases* as they get further away. And also, importantly, every galaxy is uniformly moving away from us. Take a second to think about that - there's only two real possible explanations for this observation. \n\n* All the galaxies are moving away from us because we are at the center of some sort of cosmic force that threw everything away from us and we're at the center of it. This goes against a lot of principles in cosmology, most notably that the universe is homogeneous and isotropic. That is, that the universe is the same everywhere and in every direction. Saying there exists a \"center\" would make that center point different from everywhere else.\n\nOR \n\n* Space itself is expanding, filling in the gaps everywhere with more distance. \n\nThe numberline analogy has always worked best for me: imagine the universe is a numberline from minus infinity to positive infinity. The Earth is at some arbitrary point, say 42, on this numberline. Every galaxy, the one on 40, the one on 80, the one at -200, are all moving away from us. To assume that every other galaxy is just running away from 42 would be rather vain! A better explanation is that the numberline itself is expanding. Stretching, if you will. Pretend there is a scale factor that the entire numberline is multiplied by. As the universe expands, the scale factor grows. Its like all the numbers on the numberline are getting multiplied by a scalar. So instead of us being at 42 and the other guys at 40, 80, and -200, in the future, when the scale factor is twice what it is now, we will be at 84, the other guys will be at 80, 160, and -400. See how the distances are all bigger? We used to be 2 away from our neighbor, but now we're 4 units away. And the guy at -200.. he used to be 242 units away, now hes 484! It neatly explains why distant objects are receding faster, and does not rely on us being at the center of the universe.\n\nEDITed because I accidentally a word or two."
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9i07t3 | are muscles an obstacle in surgery? | For example if someone needs to get their belly sliced open could strong abdominal muscles be a challenge for the surgeon? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9i07t3/eli5_are_muscles_an_obstacle_in_surgery/ | {
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"Not really. At least, it's much easier to deal with compared to excessive fat. With even very muscular people, the muscle can be pulled back and clamped once it's out of the way. With excessively fat people, it usually requires a surgical intern to hold the fat back through the procedure because it's too thick/weak to be clamped.\n\nNo idea about muscle-bound powerlifters, though.\n",
"No. The anesthetist will administer paralytics which can completely relax skeletal muscle. There can definitely be a difference in the ease of retraction of skeletal muscle by the surgical team based on the patients body habitus (say college football player vs 80 year old frail woman), but nothing that cannot be mostly or completely overcome pharmacologically."
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251eec | proposed internet fast lanes | My current internet provider offers 4 different levels of service. Each offers progressively faster speeds and costs more money. Everyone has the same maximum bandwidth usage. How will the proposed "internet fast lanes" be different from what the internet companies are currently doing when they charge for faster speeds. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/251eec/eli5_proposed_internet_fast_lanes/ | {
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"Some websites will be faster than others. But in this case \"faster\" will be the current speed, while the \"others\" will be slowed, as they don't pay premiums. It's more money going to ISPs without any advancement ",
"The proposed \"fast lanes\" aren't consumer-facing, they apply to the backend connections between ISPs and websites.\n\nISPs want the individual ability to extort websites for the privilege of connecting to their customers without degraded speed. This not only means that current sites could cost more (see the recent announcement of a Netflix hike) as they start passing on costs to customers once have to start paying all the major ISPs extra \"protection money\", it actually endangers new innovation because these extra costs are something that startups often can't afford.\n\nIn a nutshell, these ISPs have a monopoly due to lack of competition and regulation, and they want the ability to abuse the hell out of it.",
"It's extortion. Pay the ISPs protection money or they'll intentionally slow your traffic."
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7jko9y | Did the U.S.S.R and its Navy have a ship prefix for their ships? | For example England has "HMS", the United States "USS" but I have been trying to find the Soviet Union's ship prefix and cannot find anything, did they simply not have a ship prefix? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/7jko9y/did_the_ussr_and_its_navy_have_a_ship_prefix_for/ | {
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"No, they did not have an official ship prefix (which is not completely unusual -- the Imperial Japanese Navy and Kriegsmarine both did not, although authors will sometimes add prefixes to ship names to identify them.) \n\nYou will sometimes see Soviet ships referred to as \"USSRS\", although a literal transliteration using Cyrillic would be KCCCP -- the acronym would be for \"Корабль Союза Советских Социалистических Республик,\" \"ship of the Union of Soviet Socialist Republics.\" "
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n8zyp | Can a sound effect a person's nervous system? | Can a sound affect a person's nervous system? For example could a sound make a person feel as if something is happening to his body such as the feeling of being touched by something. | askscience | http://www.reddit.com/r/askscience/comments/n8zyp/can_a_sound_effect_a_persons_nervous_system/ | {
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"Sound absolutely affects a person's nervous system, that's how we hear. \n\nBut, more in the spirit of your question, there are [Infrasounds](_URL_0_) that are a really low frequency and have been hypothesized to affect humans & animals physically. Specifically, they have been correlated with feelings of awe/fear, nausea, and pain. ",
"Sound absolutely affects a person's nervous system, that's how we hear. \n\nBut, more in the spirit of your question, there are [Infrasounds](_URL_0_) that are a really low frequency and have been hypothesized to affect humans & animals physically. Specifically, they have been correlated with feelings of awe/fear, nausea, and pain. "
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1xrbjq | chemtrails are not real | Not for me, both ye huddled masses of chemtrail conspiracy theorists. I've seen too many posts on Facebook of airplane contrails claiming that they are controlling the weather. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1xrbjq/eli5_chemtrails_are_not_real/ | {
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"Are you asking a question? ",
"As I tell the children at work, a statement is not a question.",
"There's usually not much you can do to sway their minds. You can lead a horse to water but you can't make it drink. ",
"Well, [see for yourself](_URL_0_). You can see the forward edge of the contrail inflight sometimes if you've got a good back seat window. Then read the scientifically factual [Wikipedia article](_URL_1_).\n\nCarl Sagan's *The Demon-Haunted World* is a good read that explains why people tend to be drawn to bullshit ideas.",
"Airplanes have nothing onboard to create a chemtrail with. The *only* connections sending fluids to the engine from the airplane are the fuel line and (on some designs) an air line. Air and jet fuel can't create a chemtrail. There is no place on a jet to store any funny chemicals in a way that you could get them to the engine. \n\nBurning jet fuel does create CO2 and water. Water at high altitude can condense out to form clouds, which is what we call a contrail.\n\nSource: aeronautical engineer ",
"When I was in high school and early college, I was on the chemtrail bandwagon. After doing more research as an adult, I realized how ridiculous it is. However, there is such thing as cloud seeding which doesn't necessarily control the weather, but it does, in a sense effect it. How I understand it, correct me if I am wrong, is that chemical agents are released at a low altitude while there are rain clouds so that they will produce more rain.",
"Okay, I'll bite.\n\n'Chemtrails' are [contrails](_URL_1_) - those long, white fluffy streaks in the sky that follow airplanes around. Anyone whos taken high school chemistry should know that when hydrocarbons (jet fuel) burn, one of the products is water. Shoot this hot water vapor into the cold air of the atmosphere and - much like your breath and a really cold day - the vapor will shrink and 'condense', and form clouds that come out of your piehole, or out of a jet. Changes in pressure can also cause water to condense out of air.\n\nOn [chemtrails](_URL_0_) - what part should be disproven? The part the says they're spraying chemicals on us to control our minds? To control weather? To make us sick?\n\nWhat tests are being done to prove these 'chemicals', or whatever agents there are, are being dumped on us? [Here's a goofy account](_URL_2_) saying that there was 'contaminating levels of aluminum' found in water samples in areas over where these chemtrails were being sprayed. Here's the deal - there is aluminum in dirt. Obviously, lakes have a lot of dirt in and around them, so it would be strange to think finding aluminum in a sample should raise an alarm. Why is the only and first explanation of aluminum, a metal found in nature, being found in nature, that the government (or *somebody*, cue spooky ghost music) is spraying on the population for nefarious causes?\n\nBy the way. Do you know how much aluminum would have to be sprayed out of an airplane **at that height** to uniformly raise aluminum levels to toxic levels? **A lot.** Do you know how much that would weigh, to jam an airplane full of aluminum? How does it get off the ground? And how much it would cost to buy and spray that much aluminum into the sky? Because that seems like an *enormous* waste of aluminum. And for what? Weather control? How does aluminum 'control' the weather, exactly? Or mind control? *What?* Or as a giant weapon?\n\nAsking somebody to prove that chemtrails aren't real is like a religious person asking an atheist to prove that god isn't real. You *can't*, sort of by definition, prove that god doesn't exist at all, or prove that things aren't being sprayed out of airplanes. Have we sprayed terrible things out of airplanes before? Uh, yeah. Look at Vietnam. Are they spraying anything now? I'm going to say probably not, but who knows. However, the explanations to what it is and why from chemtrail believers are generally quite ridiculous, and the emphasis should be on *them* to prove that their claims are correct, not for people to prove to them that clouds are clouds."
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5kxxz7 | Is it possible to calculate the average chance of winning a 16x30 game of Minesweeper with 99 mines, assuming perfect play? | I saw [this frustrating windows Minesweeper picture](_URL_0_) on /r/gaming, and it got me thinking that it must be a statistical impossibility to maintain a 100% win rate, even with perfect play on that "expert" 16x30 grid of minesweeper with 99 mines. No matter how perfectly you play, some games will force you to occasionally have to make a guess, as is the case in the image that I linked too.
If we can assume that we have a perfect player, who always makes the most highest probability selections (in other words, if there is a 100% "safe" square, it will always pick that before attempting to guess on a 50/50 safe square, and if there is a square that has a 2/3 chance of being safe, it will pick that before picking a square that has a 50/50 chance of being safe, then what would percentage of wins would the "perfect player" most likely approach?
Other assumptions:
* The first click will never result in a mine exploding -- > the game is generated AFTER you click your first square.
* Mine placement is completely random, except for the first clicked square.
* The Mines can not change position after the board has been determined on the first click.
Thanks Reddit! | askscience | https://www.reddit.com/r/askscience/comments/5kxxz7/is_it_possible_to_calculate_the_average_chance_of/ | {
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"Easiest way I can think of solving this would be to take a Monte Carlo Method approach:\n\n1. Code the AI to play Minesweeper\n1. Code the generator to construct levels\n1. Run on millions of test cases to get a near estimate.\n\nThis is a standard approach for \"hard\" games (ones with nontrivial rule sets and sequencing) though there may be mathematical simplifications to make this actually provable.",
"Can you describe this perfect play? In game theory, a solution to a game is optimal if it perfectly maximizes your chances of winning. But even coming up with a candidate solution for a game like Minesweeper is difficult. \n\nSay your first click reveals a lone 1. What's the best way to proceed? Should you hunt down the 1? Should you click somewhere else randomly? Should it be a combination of the two? Can you generalize this into any scenario that requires guessing (e.g. a good strategy might have you only guess based on estimated probabilities of hitting a mine at a given spot, given known information about adjacent markers and the number of mines remaining in the game). How do you account for every kind of advanced technique, like looking at many adjacent markers to figure out which spots can or cannot have mines? You might not realize it, but there's a ton of complexity to this game, and even coming up with a good general strategy for playing Minesweeper would be difficult. Trying to prove your strategy was the solution would be even harder. Then and only then could you understand how often \"perfect play\" will succeed at the game. \n\nFor reference, in total there are (480 choose 99) or about 5.6x10^104 possible game boards. That's a lot of possibilities to account for - far too many to have a computer actually check them all. \n\nEDIT: My scenarios clearly were too simplified (yes, you go for a spot adjacent to the 1), so try this one on for size. You've reached a scenario where you have to guess because there are no spots that can be determined as either 0% or 100% chance of a mine. Almost everyone so far has been fixating on probabilities, assuming that the optimal strategy will be to always guess at the least likely spot, because it has the least chance of blowing up and immediately ending the game. However, I suggest that sometimes, it will be better to guess at a higher-probability spot. What if one of those spots has a small chance of containing a mine, but clicking on it wouldn't reveal enough information to allow you to continue, so you'd then have to make another guess. Meanwhile, you could have originally chosen a more illuminating but higher probability spot. \n\nIn the first strategy, although you are always guessing \"optimally\", you might be exposing yourself to unnecessary risk. The combination of multiple guesses might make you more likely to explode than taking the second strategy and making only a single, more effective, yet higher probability guess. \n\nAs a more concrete example, revisit the lone 1 scenario. Is it truly better to click on one of the adjacent tiles? Or is it better to click on a tile a short distance away in order to gain a better understanding of the game board? What nearby tile do you choose? Can you mathematically prove one or the other gives you better chances of success on average? \n\nThis is just one such complication. Yes, you could use a Monte Carlo approach to approximate the win percentage of a player who always chose the probability-optimal tile. But this won't necessarily constitute a solution to the game, as there are many other strategies which may beat this immediate optimum over the long run. ",
"As far as I can tell, you're basically asking \"How many indeterminate positions do you encounter, given a random starting point?\". Turns out there are a LOT of ways to have indeterminate positions, but if you pick only the most likely ones (The ones you've probably seen yourself) it should be computable from there.",
"It's rare to not have to make a guess in an expert game - I'd wager in less than 5% of boards. People who play for speed always guess when it's faster - even if you could uncover tiles later that make the solution apparent. (source: my best time is 70)\n\nNeedless to say, the new version with a pop-up after every game is unplayable.\n\nIn order to have the best chance of winning, though, you couldn't simply rely on which square had the best odds. Often times, if you say have a small square revealed or a wall going from one side of the board to another, the best 'odds' may be any square in the great grey sea. But some of these squares will synergize better with the squares you've already revealed.\n\nAlso, it might be a technical note but in at least one version of the game, the board is generated before the click and is then possibly modified by the location of the first click. A cheat that changes the upper-left pixel of the monitor demonstrates this. I'm not sure how the new mine is chosen - randomly or the first available space."
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203pnx | how do tv shows make money by putting their shows on netflix and how can netflix pay all the networks and only charge 8$ per month? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/203pnx/eli5_how_do_tv_shows_make_money_by_putting_their/ | {
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"$8 a month * 23.6 subscribers = 188.8 million a month of income.",
"All of our parents that pay for Netflix and watch one movie a month.\n",
"The content put on Netflix is mostly older stuff that has already made money though regular channels and now Netflix offers a small extra profit which is still better than nothing. \n\nBut were those shows/movies to rely on only Netflix for their income, then they would lose money. \n\nReally each network should just have it's own web site to stream their content and put their commercials on. I imagine the problem is that the cable companies would drop them and the switchover period from TV to online of viewers would take too long for them to just switch and not go broke losing cable.",
"Television and movie license deals are also based on what window you get. The first window is the right to broadcast a show first. That goes to the major network that first plays the show and they more than pay for the production costs with that license fee. (At least in the US market) Once that window expires the distributor can sell it to anyone, but the price goes way down. So when The Walking Dead comes to Netflix a year after it was first broadcast on AMC, Netflix pays only a fraction of what AMC paid for the first window. Movies are similar, first window is the theatrical release, then DVD, then cable specialty movie networks then plain old broadcast tv. Netflix can presumably jump in at whatever point in that cycle that a given movie is worth it to them. They have amazing metrics, so they know with a high degree of certainty how much value their viewers will get from any given movie and can pay license fees accordingly.",
"It's worth pointing out that the networks don't actually sell the shows to Netflix. The studios that produce the shows sell the networks exclusive rights to broadcast them, then once that period of exclusivity is over, the studio will sell the broadcast rights to services like Netflix. Recently, networks have begun negotiating for digital rights along with broadcast rights, which is why they can show the, um, shows online with ads. ",
"TV shows make money by selling the rights to Netflix, often for a limited amount of time. This practice is called syndication, and is typical for older shows. Lets take The Office for example. The Office was produced by NBC, and therefor NBC owns the rights to all of the episodes of The Office. NBC can sell the rights to The Office (or any other show) to Netflix, which is great for NBC because they make money without having to make anything new, since the episodes already exist. \n\n\nWhen Netflix rents a show, they do it at a relatively low cost (the specific numbers are never released, but both sides benefit equally). Netflix is only given the right to stream the episodes they've purchased online to their subscribers. NBC can still air episodes of The Office whenever they'd like, it just gives them another source of revenue. \n\n\nHope this helps! ",
"I'd love to see the numbers on how many people subscribed to Netflix because of the season 2 premier of House of Cards. Would be nice to see if that model is working for Netflix. I'd like to see them succeed with it, as that show IMO kicks some serious ass.",
"Ken Burns made a [short video about Netflix for Bloomberg Tv last year.](_URL_0_) He basically says the access to content is great, but the money made from PBS selling rights to Netflix doesn't offset the decline in DVD sales. He sees an upcoming front of artists organizing to get rid of middlemen like Netflix.\n\nEdit: clarification ",
"they actually get the rights to play content on contract, so they haven't paid for a lot of content that is available on neflix.",
"Short answer: You'll wish the prices went back down to $8/month in the near-future. ",
"And how does spotify do it?",
"This helps:\n\nNetflix's most profitable markets are the ones where it doesn't officially exist.\n\nNetflix doesn't pay any licence fees in countries where it's not officially available. For instance Netflix sells into Australia by VPN. It doesn't pay any licence fees for Australian rights to the content creators - it just banks the dough.",
"Another question: why Netflix releases whole season of HoC in one day? Can't people just buy one month subscription to watch whole series of HoC and then never buy it again? Wouldn't they get more money by weekly releasing?\n",
"One point that no-one is mentioning here is that a non-trivial portion of Netflix users will be paying for the service and not using it. Paying users who aren't using the service will change from month to month, but Netflix will have metrics on how the total figure per month, and overall there are probably predictable trends. Then of course there will be the users who pay for Netflix, but use it a very small amount - these users are also disproportionately profitable for Netflix.\n\nLower-consuming users will be offsetting the cost for higher-consuming 'power users', who are likely in the minority. If everyone used Netflix like a college-house use it, the model probably wouldn't work at it's current price point.\n\nThe same goes for other on-demand subscription services like Spotify.",
"Broadcast rights are MUCH cheaper than distribution rights. Netflix only pays the broadcasting fee, not the distribution fee, because they are all DRM'd up. ",
"There is a lot of misinformation in this thread. \n\n1) Its like syndication. Sometimes Netflix pays top dollar for quicker access to content, other times they pay a much more reduced rate for what used to be a standard syndication pay table. As you have noticed most NETFLIX content comes out after the show has run its season on TV, and then a month or two after the DVD is released. After about a month of a DVD being out - most media companies stop focusing on the revenue earned from a show or a movie - then NETFLIX swoops in a gets a great deal because FOX, UNIVERSAL, ETC see it has guaranteed extra earnings on whatever property NETFLIX is licensing. \n\n2) Now - as far as local stations paying for content, Almost all local stations are affiliates of larger conglomerates. Namely FOX, ABC, CBS, or NBC. Those local stations make decisions (as well as the parent network) on what exactly the local stations will show. Those local stations obviously have their own original content, but will simulcast most major shows - thereby the do not have to pay extra. \n\n*edit* Source: I work in T.V",
"House of cards has quite a bit of product placement that i'm sure makes money. \"Is that a PS Vita?\" \"This pizza (pizza hut) is really good.\"",
"A lot of people are going on about commercials. I have no commercials on my netflix. Have I just lucked out, or are these people just guessing having not actually used Netflix themselves?",
"How can Netflix make money with streaming? That's a good question. Historically their cash cow has been DVDs. That profit is due to them being able to buy the DVD once and then lend it out many, many times (First-Sale Doctrine). This essentially equates a fixed fee (consistent monthly charges) with fixed cost (pay for the DVD once).\n\nThe issue with streaming is that it becomes a fixed fee-variable cost arrangement. Each time you watch a movie, Netflix pays something. So as people watch more, they earn less and less money.\n\nIt would seem that at some point they will have to tier the membership fees for usage to get past this problem.",
"The majority of a network's income comes by way of advertising. Netflix is a drop in the bucket by comparison. ",
"I really think people are underestimating how much money they make off subscriptions. They have over 40 Million subscribers who pay around 120 dollars a year for their services. That comes out to 4.8 BILLION DOLLARS. ...even if they invested 80% of their profits back into their business they would still be making hundreds of millions of dollars. \n\n ",
"They use a completely different business model than the more common business model used by many major corporations called, \"Fuck Your Customer Over\".\nTheir model of course is not one highly recommended by MBAs and other business management types.",
"Economy of scale. $8/mo isn't a lot - but $8 x 25million = $200million/month. That kind of money is plenty to pay the content distributors for the rights.",
"Warner brothers, is that you? ",
"They gross about $4b a year, but net income is only about $100m. That's about a 2.5% profit margin, so they're clearly paying an exorbitant amount of money to license content.",
"Wow someone's reading my mind. I was laying in bed last night thinking the same thing. Saying to myself I should ask reddit",
"Economist and law student here; there's two parts to my answer.\n1st-License is non-exclusive.\n2nd-Is netflix really stealing TV/DVD/PPPV viewers?\n\nNetflix offers distribution companies and IP holders a legal form of price discrimination. To use a form most people are familiar with, think of what happens to the price of an airplane ticket as departure approaches: the price rises, rises, rises, then suddenly drops. Once the airline decides to actually make the flight, any butt in a seat, regardless of how much the customer paid for it, is a profitable endeavor. This is why you see a massive drop in price in the last 12 hours before a flight.\n\nSimilarly, IP content is only worth something if people watch it. The question content-creators have is \"how much does netflix pirate viewers that would otherwise watch my content on TV/PPV/DVD, all of which have a higher profit margin for me?\" HBO, as a pay-per-view service, knows that that answer is \"an enormous percentage of my viewers,\" so it doesn't put things on Netflix or Hulu. \n\nOn the other hand, NBC knows the answer is \"not many,\" at least for the shows it puts on Netflix. I'll watch the office randomly on TV if its on, and the availability of the Office on Netflix doesn't impact that decision. On the other hand, if I get a random urge to watch the Office, and it isn't on TV or Netflix, that's lost income for NBC. \n\nTLDR: Put a show on Netflix if Netflix viewers wouldn't otherwise watch the show on a more profitable medium. At that point, any revenue is additional profit, since you're getting views that would otherwise be lost. ",
"I have a follow-up question. ELI5 why Netflix will continue to produce original content. At some point aren't they going to max out for their subscriber base? Is the feeling that they will need to keep producing original series to retain the subscribers? Is producing your own content more or less affordable than licensing other content?"
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1aqszs | When a new ISP is started (e.g. Google Fibre) what do they connect to to join the world wide web? | askscience | http://www.reddit.com/r/askscience/comments/1aqszs/when_a_new_isp_is_started_eg_google_fibre_what_do/ | {
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"You may be interested in this article:\n\n_URL_1_\n\nBasically, the internet can be thought of as a network of networks. There are a number of top level global network connectivity providers (mostly telecom companies) who interconnect (peer) their networks at various exchanges all over the world. Seeing as they literally *sell connectivity*, at that top level the providers generally peer as equals, as it is in their interest to do so (their own network becomes far more valuable if it can connect you to the other networks as well). That's literally what makes the internet *The Internet*.\n\nThere are also other network providers and ISPs lower down on the totem pole that either have somewhat less equal peering agreements (say, paying a small fee), or just outright purchase connectivity from the top providers. These guys generally have smaller networks and so have less \"connectivity\" to offer. Basically, where you are on the totem pole is determined by how valuable it is to peer with you, which is usually directly related to the size of your network and what it is connected to.\n\nI'm not sure exactly where Google is on the totem pole, but I do know they have substantial network assets and are quite a valuable peer (after all, everyone on those other networks uses Google!), ~~however last I checked they were not one of the top level global telecoms either.~~ *EDIT: This may be up for interpretation, as kent_stor brought it to my attention below that Google's network actually caries more traffic then all but two other networks in the world as of 2010!*\n\nNow, if you mean *physically* what/where they are connecting, that would be at an exchange point somewhere. Here is a handy map I found of internet exchange points around the world:\n\n_URL_0_\n\nThese are the actual locations, generally large network infrastructure installations most people would just refer to as \"datacenters\", where the various network providers and ISPs actually physically run their fiber lines to. The lines are usually buried along roads and railways and such, though they may be on poles sometimes too. In order to interconnect at these exchange points, they rent one of several physical spaces in the building(s), install routing equipment, and run their fiber lines to it. They then run lines between their routing equipment and the routing equipment of the various other networks they have agreements with. I hear they can be true nightmares of cable management. :)\n\nAs for Google in particular, since they are deploying in Kansas City, and there is actually a major exchange point right there in Kansas City (KCIX), I strongly suspect the majority of their peer traffic runs through there. That might even have influenced their choice of city for the first roll out now that I think about it...",
"Google is not a new ISP. They have an extensive network that is well connected to the internet at just about all major exchange points. If a new ISP is starting, they will purchase service from a larger provider.\n\nYou can see how Google connects to other networks here: _URL_2_ and how Google Fiber's network is connected here: _URL_0_\n\nAlso, for those who are saying KCIX is a major exchange point, it is not. KCIX is fairly small. Most of their domestic traffic will not be going through there, but hauled to Chicago, Dallas, California, NY, and Ashburn, where the majority of bits are served.\n\nKCIX Member List: _URL_1_\n\n",
"I'd like to clarify that your question should be \"what do they connect to to join the Internet.\"\n\nThe World Wide Web is one part of the Internet, but there are many other pieces. In fact, the Internet would still work without the Web; it would just be less useful.",
"Here is an example of a fiber network by an internet provider:\n\n_URL_0_\n\nFiber is basically a cord that light goes through. It is a 'light pipe'. Light is really fast and with some neat strategies(multiple colors and such) you can pass A LOT of data through fiber.\n\nSee the end points that just seem to go somewhere and then stop? Many of those are going to other telecoms with huge connections(10gigabits per second up to hundreds of gigabits per second(50+gbit/s is common for this size of telecom)). \n\nNow, SDN operates it's own network. It makes sure that communications can go from point a to b on it's own network without going to anyone else's network. It handles setting up point to point connections where to a business it looks like their other building is directly on the other side of the fiber that goes to SDN's network(even though it goes through SDN's network) and all kinds of other neat connections with interesting/useful features.\n\nBut one of SDN's customers wants to look at a website that SDN doesn't have a direct link to on their network. What does SDN do? Well, the customer uses DNS to look up an IP address for that website. It knows it wants to talk to a specific IP address, so it asks SDN to send it's packets to this IP address. SDN now needs to know where this IP address does. This is what routing protocols do. Specifically, BGP(Border Gateway Protocol) is what controls the internet on a global scale. SDN looks at the Global BGP Table and sees that one of the points where it connects to another network is the best way to send that request. So it sends it that way. And the next ISP does the same, until the packet gets to the website server. Then the website sends a response in the same fashion.\n\nHow does the money in this work? Customers pay SDN, SDN pays employees and other providers. It branches out from there. There are some other ways(like if SDN wants an assured bandwidth connection to China, they would pay for every leg of the route)\n\nSource: Computer Science Graduate and I work in telecom",
"You can think of the internet as a bunch of nodes and connections between them. What are those nodes? Well, the ones on the ends are things like the router in your house. The ones in the middle are basically the same thing, routers, but much much bigger. What do they do? Well, the router has a single input port and a bunch of output ports. Internally, they maintain a database that maps a range of IP addresses to an output port. When internet data (IP packets) enter the router, their destination IP address is read from the packet and the server looks up \"which output port should I send this to?\" It then sends the packet along to the next router, which is assumed to be able to get the packet closer to its final destination until it finally arrives there. In this way, there is no giant central authority that knows where everything on the internet is. Rather, that knowledge is *distributed* across a huge number of routers along the way. This is nice because it means there is no central point of failure for the internet. (The domain name service, used for converting a name like _URL_0_ into its IP address, works in a distributed way as well.)",
"heres a new Question: Could i theoretically buy a large server, and create my own ISP of sorts for myself only?\n",
"Slightly relevant, here is a map of undersea cables: _URL_0_",
"tracert in Windows is a fun command in command prompt to see what points you are going through to get to whatever website it is you are trying to access. \n\n > tracert _URL_0_",
"The question in itself can be re-worded primarily due the example chosen - 'Google Fibre'. A new ISP will work entirely different to that of Google just because of the difference in scale when Google comes into the picture. I'll separate them out here and try to answer.\n\nA small ISP (say ISP A) does not need to connect to an exchange point to peer. With the [tiered architecture](_URL_1_) of the Internet an ISP can simply connect to a higher tier ISP and buy transit (typically in bandwidth/months) contracts and get online. This is the easiest and surest way for the smaller networks to connect to the larger ones and we get the typical tiered hierarchy. Now what makes an ISP tier 1? Its simply the fact that a tier 1 ISP **guarantees** you global connectivity. You can send packets to **any** network in the world if you connect to a tier 1. However, they are large corporations and would typically not want to peer with a smaller ISP simply because the traffic generated by the small network will not be enough to justify a connection. The big networks will want to do business only with the other big networks and not the small ISPs.\n\nSo the other option for the small ISP is to **peer** with another ISP which agrees to route its traffic. Now this peering could be settlement free, where both networks agree to allow traffic through their networks to their respective customers or send it upstream to their transit providers. More often though what would happen is that ISP A will get into a paid peering agreement with a larger ISP who agrees to not only exchange traffic but also provide transit. A myriad of economic details come into the picture here as both ISPs will try to maximize their profits all the while trying to make sure that they do not route more traffic than the other and thereby overload their networks - traffic matrices, bandwidth prices, contracts and so on get real complicated out here. \n\nSo, remember the tiered architecture I talked about if the ISP simply buys transit? Well with peering, a small ISP can actually bypass connecting to the larger ISP since he found another network agreeing to route his traffic. Maybe ISP A generates traffic only for ISP B. Should it then buy transit from a higher tier provider? No. It just peers with B (either privately or at an IXP) and its done. This has lead to a recent notion of the **flattening Internet topology** ([Gill et al. pdf](_URL_3_)). Peering is driving force behind this and it has far reaching consequences (i won't go into details but some work in this regard can be found in this paper by [Dhamdhere and Dovrolis pdf](_URL_0_)).\n\nGoogle fibre changes the entire picture - Google's own networks are huge and they do not need to buy a lot of transit as mentioned in the other posts. While most of their traffic they can serve and siphon off on their own network, they connect to tier 1's directly and so have guaranteed routes wherever their traffic is destined. Google does peer at major IXPs worldwide but I would think most of their peering agreements would be private and thus not readily available for us to see. This recent work by [Ager et al. PDF](_URL_2_) shows that at just one major European IXP exchanges some 10PB of traffic daily with only 400 member ASes (An AS is an Autonomous System). Also very surprisingly it found that the number of peering links at that one location exceeds the total number of known peering links between ASes in 2010. From the paper - *To put this\nnumber in perspective, note that as of 2010, the number of inferred\nAS links of the peer-peer type in the Internet was reported to be\naround 40,000 – less than what we observe at this particular IXP\nalone!* \n\nThis goes to show that peer-peer links are extensive and not easily visible from the outside. Why this happens is an active area of research and not totally relevant to the question asked (and yes I think I have already digressed a lot) here. \n\n ",
"**Short answer: to existing ISPs.**\n\nGoogle is a very special case, but I can tell you how it would normally work. \nSource: I work at a small ISP. I wasn't there when they started, but I know roughly how it happened.\n\nBasically, you buy some connectivity from an existing ISP, a Tier 1, 2, or 3. (See [WP: Peering](_URL_1_) for more on that system.) Traditionally, this would have been a [DS3](_URL_0_), but now you'd likely get some kind of fiber or Ethernet. Hopefully, you get connectivity from more than one ISP. Oh, and call them “carriers,” not ISPs, so you don't sound like just an end user.\n\nYou also buy a block of IP addresses that you can divide up and give to your customers. \n**Now, this is what fundamentally separates “being an ISP” from “charging your neighbor to use your WiFi.”** These are public IP addresses, which are globally unique, and getting pretty scarce now. In America, they're kept track of by the [American Registry for Internet Numbers (ARIN)](_URL_2_). (Check the top of that page for your public IP.) What really makes you an ISP is when ARIN recognizes you as one, and assigns you some IPs. But they won't do that unless you're already administering some IPs. Catch 22. \nSo you get your carrier to give you a few, register them with ARIN, and use them for your first customers. Meanwhile, you hassle ARIN until they agree that you can play with the big boys. Then they'll give you your very own IP block, directly, and you'll be a real ~~boy~~ ISP.\n\nYou also buy some (Cisco) routers and switches that can handle a bunch of traffic and do some fancy stuff like combining your big pipes and splitting them into smaller ones.\n\nNow you've got connectivity between your office (or space you rent in a data center, more likely) and the internet, via your carriers. You've got IP addresses. And potential clients are beating down your door to get internet from you. (I assume. I skipped the marketing steps; that's black magic to me.) You just need to get it from your equipment, to them. You can't go tearing up the streets to lay a bunch of cables, so you lease existing copper (or fiber) from your carrier. They connect up one side to you and one side to your new client.\n\nNow, as you grow, you'll connect up to more other carriers, with fatter pipes, until you ~~go bankrupt after an accounting scandal~~ are an integral part of the [big web of interconnections](_URL_3_) that make up that cloud in most network diagrams.",
"There's a cool video documentary somewhere about _URL_0_ - a major interconnection point. There's people who think the internet is some fluffy thing that floats about on clouds - in reality it's millions of tons of cable and machinery so heavy regular buildings need structural reinforcement to take the weight of it. ",
"Ah, I remember the days when a huge percentage of the traffic on the net ran through one overheated storage room in a parking garage in Tysons Corner, VA.\n\n//get your bits offa my lawn"
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7lycb6 | how does an electricity company know how much electricity you use? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7lycb6/eli5_how_does_an_electricity_company_know_how/ | {
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"It measures the current and the voltage and determines the power usage from that\n\nYou can measure current by putting a tiny resistor in the path and measuring the voltage across the resistor or by looping wire around the current carrying wire and inducing current in the loop.\n\nOnce you've got the current and voltage you multiply them together and increment the watt-hour meter at the right rate\n\nGood power meters also measure the voltage. Voltage should be constant but can drift or just be a bit off. 120V countries could have 110-130V at the outlet so assuming 120V can result in inaccurate power measurements",
"The meter measures both voltage and current going into your building/home/whatever to calculate the amount of electricity you're using. Voltage remains the same, but the current flowing in does change when something is drawing electricity from the circuit.\n\n > ...and the amperage depends on the appliance (it doesn't change in the house circuit but in the appliance itself)\n\nAh, but it does: your house circuit is only pulling the current it's using, it's not constantly doing this. When you switch on a bulb, the amount of current you're drawing from the mains increases.",
"Devices in your house use power for a certain period of time. Let’s say you use a lightbulb that is 10W for 30 minutes. The total usage would be 5W x hours. You are billed usually in kilowatt hours. Your power meter calculates these by measuring the amount of current flowing into your house over a period of time. I could give such a better explanation if I wasn’t on my phone lol. I’m not an electrician so I’m not super familiar with the household metering devices, but I am an electrical engineer. But basically they measure the amount of current flowing on the main power line going into your house and get a calculation of kilowatt hours with which you are billed for.",
"The old-fashioned kind of electric meter with all the little clock dials:\n\nThere are certain classes of motors whose rate of rotation is proportional to the voltage that's fed into them. Load and other considerations have very little effect.\n\nSo the main power line into your house passes through the electric meter. The meter has a very-low impedance resistor that the current has to pass through to get into your house. The resistance is small enough that it doesn't effect your household electricity, but it's enough that there's a very small voltage across it. That voltage will be exactly proportional to the current flowing into your house.\n\nSo this voltage that's proportional to the current you use is fed into a tiny electric motor that turns slowly, and at a rate that's exactly proportional to the current you're using. That little electric motor is turning clockwork gears that cause the hands in the meter to slowly move.\n\nOnce a month, the electric company sends someone to look at that meter and note the reading. This tells them how many amp-hours your house used during the month. Then they multiply that by 120V to get the watt-hours you used, and bill you accordingly.\n\n----\nThe fancy new electronic meters:\n\nThere's a computer in there."
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20ad6t | videogame emulator "save-states". how do they compare to modern save-files used outside of emulation? | Say for example that I had gone through all of the necessary measures in order to make it [nearly] legal to emulate my Gamecube games on my PC.
Say I decide to use Dolphin emulator to play the game that I own on disc but had ripped to my PC for the sake of science. Legally.
Dolphin allows me to hotkey into a save-state at any point during my time playing said game. I open the save-state when I want to play again, and I find myself right where I left off, even in the middle of an action sometimes.
Traditional saving would have brought me back to the "beginning" of an area, or perhaps back to the designated "save-point"
Are these methods any different from one another, or is the reset-type load of save- *games* a tool that developers use to keep players from gaming the system or whatnot? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/20ad6t/eli5_videogame_emulator_savestates_how_do_they/ | {
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"They're completely different things.\n\nA traditional save point is something created by the developer. There is some collection of variables that they are recording--say, which save location you are at, your inventory, and what your characters stats are. This obviously varies from game to game--maybe some games don't have levels or inventories, and it's just a list of what races you have completed, and your best time for each. In that type of game, your save is probably a lot smaller.\n\nSaved games are specific to the game.\n\n\nA save state is completely different--it's literally the emulator taking a dump of all things that are going on at the time.\n\nSaved states are specific to the emulator."
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29bisr | Are commercial airplanes flying as fast as they can fly? | Understanding how things like headwinds and tailwinds can change how long a trip takes, I couldn't help but think: there is no way my plane is going absolutely as fast as it can. If a plane is running late, or up against a strong headwind, couldn't they just step on the gas a bit? | askscience | http://www.reddit.com/r/askscience/comments/29bisr/are_commercial_airplanes_flying_as_fast_as_they/ | {
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"Commercial airliners are operated rather close to their maximum rated speed. The [wiki page for a 747](_URL_0_) lists the cruise speed at 555mph and max at 594mph.\n\nYou have to understand that airliners are run on a rather thin profit margin and fuel costs a *ton* of money. They wouldn't fit an engine that could perform substantially better than required because it's a waste of money and adds unnecessary weight. They generally won't 'step on the gas' because it blows out any profit they may make on the flight in increased fuel consumption.",
"They're not flying as fast as is *possible*, but they are flying the speed that makes economic sense. Fortunately for impatient travelers everywhere. those speeds are very nearly equivalent. Take the Boeing 787 as a typical airliner. Its top speed is Mach 0.9, and its cruise speed is Mach 0.85 (at 35,000 feet). The difference between those speeds is only about 5%. \n\nThe reason cruise speed is lower than maximum speed is that cruise speed is where the plane is most fuel-efficient, and therefore a) has the highest range and b) can carry the most passengers. The pilots *might* \"step on the gas a bit\" if they can get away with it (passengers and range vs remaining fuel allow them to increase thrust) but that costs the airline more money, so I suspect if they want to do such a thing they need to get special permission from the dispatcher.",
"Commercial planes fly at the speed that makes the airlines the most money. This is a very heavy duty math problem. You need to factor in the prevailing winds (weather is a huge factor), the load of the plane, weight and number of passengers, baggage, food (yup, those carts are heavy even if you just get a snack), crew number and weight, the impact of the schedules of other planes, the cost of fuel, the \"cost\" of being early/late, the plane, the plane model (those winglets on the tips of the plane's main wing affect fuel consumption by full percentage points), and this is an incomplete list. Going as fast as possible may decrease air time but may add more to maintenance time -- the list keeps growing. There are enough factors that \"fast\" is not as important as \"best.\" Best for airlines has a lot of answers that passengers may not like.",
"Air traffic control bottlenecks will also contribute to the inability for a flight to get to destination \"as soon as possible.\" Any phase of flight outside cruising is going to be at the mercy of ATC and speed regulation is a very important part of their separation & routing procedure.",
"There is a difference in planned speed, Econ speed, and what the pilots actually fly. \n The planned speed is what we get on our paper release and they are all based on forecasted weather, winds, airplane weight, and passenger count by the dispatcher. Since these are all forecasted, it is kind of a useless number, because all those factors will change by departure time.\n Econ speed is generated by our on board flight computer ACARS, it measures everything in near real time to come up with the most economic speed.\n Sometimes ATC can assign a speed, or if on an arrival or departure procedure there are published speeds. In certain airspace there are speed limits, and in the USA max speed below 10,000ft is 250kts. However it honestly is dependent on the guy flying. We get paid by the minute, so if I need extra money this month I will taxi slow, and fly slow. If it's our last leg of a long trip, warp speed!\n",
"All Aircraft have a critical mach number, this is the point of which the aircraft could be damaged.\nMost comercial aviation traffic flies .83-.85. Typically a company wants to get the pax to their destination as fast as possible with the smoothest ride trying not to use a lot of fuel. \n\nThis is where something called a cost index comes in, each aircraft has a cost index, the higher the cost index the quicker you get to the destination (typically) it ranges from 1-800 usually.\nWith companies like Ryanair using 300-500 and British Airways 40-100. \n\nHeadwinds and tailwinds. \n\nA headwind will not affect the indicated speed however the ground speed will reduce depending on the strength of the headwind slowing you down. \n\nA tailwind will also not affect the indicated speed, but will boost the ground speed.\n\nIf there's a set indicated speed of 320kts at 36000ft flying eastbound over the Atlantic, the Jetstream is behind you, therefore pushing the aircraft, Which could give you a ground speed of up to 900mph, often the wind over the atlantic is very strong flying eastbound, usually ranging between 100-150mph. \n\nSo to answer your question yes aircraft could 'step on the gas' but only marginally. ",
"The limiting factor here is transonic drag and the relationship between True Air Speed (TAS - The speed relative to the air surrounding the plane) and the Equivalent Air Speed (EAS - the speed measured over the ground). You can have a higher equivalent air speed in a tailwind, because the speed limit of a plane applies in the true air speed frame.\n\nAs a typical aerofoil experiences an oncoming normal air speed of Mach 0.7, it will begin to enter the transonic regime. This means that you get significant supersonic regions over the suction surface of the aerofoil, this results in shock and a significant increase in drag. \n\nIn addition the shock triggers separation over the control fins, resulting in loss of control. This can result in irrecoverable nose dives, as was the case in a lot of the first attempts to break through the sound barrier just after the end of the first world war.\n\nThe way that this is gotten around in modern aircraft is with swept wings. By sweeping the wings you can get up to Mach ~0.85 because as the normal wind speed reduces by a factor of cos Alpha, where alpha is the sweep angle (Think of the difference between a spitfire and a 747). This was one of the biggest contributions of the scientists recovered from Germany, as far I'm aware.\n\nThis means that the speed of the flow normal to the wing is still bellow Mach 07, whilst the forward speed is higher. This however results in complex 3d flow patters over the wing, making design increasingly difficult.\n\nThis transonic regime has been a problem for a long time, and is euphemistically referred to as \"coffin corner\" on a flight characteristic map. _URL_0_ The big problem is that in order to fly faster you must fly higher in order to avoid this mach number limit but eventually you reach a dangerous balance between these too.\n\nI can clarify if I've been unclear.\nSource: Aerospace Engineer",
"A somewhat relevant fact to this topic is that there actually were commercial planes that were faster than the ones we use now. Concorde jets flew at supersonic speeds and made transatlantic trips in half the time it takes the commercial planes we fly in now.\n\nThey built 20 of them before retiring the concept in 2003 due to low ticket sales. Supposedly one crashed in 2000 (due to a piece of something coming off a different plane that took off before it) and the decline in overall ticket sales following 9/11 were what eventually put an end to them. It's unfortunate because, from what I understand, they weren't any less safe than the slower jets we still fly today. I didn't read through the entire article though, so maybe there were a few other drawbacks I'm not considering (likely economic ones).\n\nSource: _URL_0_",
"Airlines care about money. Running a plane at top speed burns more fuel - expensive fuel. Airplanes are typically flown at 8/10ths or 9/10ths as fast as they can be flown to save on fuel and probably also wear and tear on the equipment.",
"It's extremely un-economical for commercial planes to fly any faster than they do. They fly at the speed that is most efficient given how they are designed, but that speed is only what it is because they are designed to fly at that speed. Different planes are designed to fly at different speeds, ranging from low speed crop dusters to supersonic fighter jets. \n\nThere is a big problem when you start approaching Mach 1: The transonic regime. This regime begins when any part of the flow around the airplane's wings goes supersonic (the air flow around the wing is not going the same speed at all locations; it varies drastically). So, when the fastest part of the flow (usually at the top of the wing just behind the leading edge) goes supersonic, even though the whole plane is still going subsonic, you start to get shock waves. Shock waves are a phenomenon that occur in supersonic flow, and they cause LOTS of drag and really screw up your fuel efficiency. Also, you also get really weird things that happen with your lift dropping drastically near Mach 1 and then jumping way back up suddenly (just before Mach 1), and that also causes inefficiencies because you have to control the plane through all of that.\n\nBasically, once the plane gets to a speed where shock waves start to appear (around Mach 0.85), your drag jumps way up and so does fuel consumption and cost. The Concorde had to simply push through the transonic regime with really powerful engines, but once it did it could fly a really fast speed that could get you from New York to London in about 3 hours (way faster than a 747). The problems of the transonic regime mostly go away after about Mach 1.2, and you can actually get some pretty nice aerodynamics in supersonic flow. However, any plane that is designed to fly supersonic pretty much sucks at flying subsonic, so the plane was extremely inefficient while it was getting up to cruising speed. Also, in order to fly supersonic efficiently, you have to have turbojet engines (as opposed to the high-bypass turbofans that most commercial planes use). Turbojets can give you a lot more thrust, but they aren't nearly as fuel efficient. Also, another big drawback to them is that they are really **loud**. Turbofans are significantly quieter than turbojets, and as such a plane like the Concorde could not realistically fly anywhere near commercial areas (the sonic boom was also really loud so that just added to the problem).",
"As you approach Mach 1, your airplane starts to have parts of it experience the Mach effect. There were airplanes for commercial use that could go above Mach 1, they were called concorde. Why don't they fly anymore? Cost. Fuel efficiency is essentially why we don't end up going as fast as the airplane can.\n\nMost big Boeing aircraft have a top speed between M.89-M.9, but they have different 'most efficient' cruise speeds: 747 is around .86, 777 is around .83. Airbus airplanes are often a little slower, but then again, so are smaller aircraft of any make.\n\nThe answer to your question is mostly this (after a long long meander about): We are going as fast as it is commercially expedient to do. There is an index of cost/speed, and of course, they go as fast as makes sense because no one wants a slow flight. Hope that made some meandering sense."
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b8ph92 | catergorical imperative | Hello all,
I was reading through some information and I wanted an explanation of why/how would cheating violate the categorical imperative?
(Please keep in mind that I'm relatively new to this kind of material so I'd appreciate it if you could keep it as simple as you can) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b8ph92/eli5_catergorical_imperative/ | {
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"In Kantian (deontological) ethics, a categorical (or moral) imperative is an unconditional moral obligation which is binding in all circumstances and is not dependent on a person's inclination or purpose. The core categorical imperative is: Act as you would want all other people to act towards all other people, or (more simplified) - That which you would not want all others to do, you cannot do.\n\nIn _The Groundwork_, Kant addresses deception as a violation of the categorical imperative. Kant asserted that lying, or deception of any kind, would be forbidden under any interpretation and in any circumstance. With lying, it would logically contradict the reliability of language. If it were universally acceptable to lie, then no one would believe anyone and all truths would be assumed to be lies. \n\nIt is fairly easy to extrapolate this to cheating in any form. With cheating, it would logically contradict the reliability of the test or game you are cheating; if it were universally acceptable to cheat, then no one would not have any faith in the tests that are meant to assess knowledge or the outcomes games that are meant to determine the \"best\" player or team per the established rules. \n\nSimplified, we can rewrite the core categorical imperative, as it relates to cheating: As we would not want all other people to cheat, then you yourself cannot cheat."
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1j3lwf | if the nsa can see everything (and assuming all other agencies can too) why don't they jail people who download illegal content off the internet? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1j3lwf/eli5_if_the_nsa_can_see_everything_and_assuming/ | {
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"It's not their job to police the American public except for terrorists. The program was relatively secret, so they didn't share the data with the other agencies that do look for illegal downloading.",
"Because computers are not lawyers!\n\nEverything you can see through your internet browser (each web page, each jpg or gif or video) is actually downloaded from a server to your local computer, and rendered on your screen via your browser. That's how the internet works: files are always and only being either downloaded or uploaded.\n\nNow say I download a image file (a jpg) that's entitled *1.jpg*. Does the computers comprising the internet know what the visual content is of that file? The computers know the bits that comprise the image, but even the most advanced computer systems can barely start to visually recognize the content of the image.\n\nSo, now say that *1.jpg* is a picture, taken by a tourist, of the Mona Lisa. There are people that would assert that images of the Mona Lisa are copyrighted, but this is the area where copyright is debated by lawyers.\n\nLuckily, computers aren't lawyers, and serve the JPG file when requested. Then the NSA might know that a browser that you regularly use downloaded a jpg named *1.jpg* - but the NSA does not have any real-time system to determine the copyright concerns, claims, or infractions of the content of *1.jpg*. *(furthermore, because there's no money or intelligence in catching you download a jpg, there's no justification in trying to enforce it too much)",
"Downloading copyright material is not illegal for the most part (only if it's fairly large scale business oriented version of piracy). You cannot be arrested for it, you won't get fined or go to jail. Instead copyright infringement is tortious. That means it causes harm to someone in a way that opens up the person causing that harm to being sued. It's up to the person being harmed (in this case the MPAA/RIAA) to bring suit against the person doing the harm, and it's not the government obligation to assist that.",
"because its not a violation of criminal law, its a violation of civil law. \n\nif you violate criminal law a police agency can arrest you because you may be causing a threat to public safety. downloading content illegally is never a threat to public safety. \n\nif you violate civil law you can be sued by an injured party. the NSA is not the injured party. they can't sue you. the owner of the copyrighted material is the injured party. they can sue you, if they can figure out who you are and what you downloaded. "
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4ianwp | How did Buddhism get so popular in America with such a different philosophy from western thought? | [deleted] | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4ianwp/how_did_buddhism_get_so_popular_in_america_with/ | {
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"I think this question is rather hard to answer. Perhaps you'd get an answer more easily if you reformulated it into a couple of subquestions, let's say \"How did Buddhism spread to the US? What kind of people were the early converts? What are the differences between Buddhism and Greco-Roman philosophy? What about 20th century philosophy?\"\n"
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5umzx5 | Historians, do you think there should be more cooperation between historians and experts in other fields? | History is a very large subject area, as there is a history of most if not all subjects e.g. mathematics, economics, geography, politics, music, art, language, science, history etc.. Do you think there should be more collaboration between experts in these fields and historians to help understand/analyse the history of these fields? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/5umzx5/historians_do_you_think_there_should_be_more/ | {
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"That's been one of the benefits of being in such a small field (art marketing, phenomenology, and authentication). I can't stick with my own kind because it doesn't exist beyond me, so I have to go spelunking myriad fields, and I've worked with with people in medical imaging, musical instrument repair, chemists, police, curators, psychologists, economists, filmmakers, auctioneers, art historians, critical theorists, theologians... whereas other people I've worked with are in much more insular research environments. ",
"There are two ways to consider this question. The first, which seems to be the intended aim, involves whether specialists in other disciplines should be involved in writing the history of those disciplines. One of my hats is the history of science and technology in colonial Africa, so that requires that I become familiar with the bodies of knowledge I discuss. The major issue in that instance is that often the knowledge I am talking about was long since banished from the active curriculum for training new scientists or technicians. This means that, while I interact with specialists in those fields, only those specialists with an interest in the history themselves are open to really extensive engagement.\n\nMy personal example involves mapping, which has changed dramatically from the age of optical survey, rough plane-tabling, and physical compilation relative to today's practices. There is, however, no shortage of geographers who have some interest in the past methods and critical meanings of their subject, so we do have common foci. Our work, however, tends to bend in different directions: mine is more involved with society, culture, and the effects of that knowledge, while they spend much more time with technical matters and issues internal to the practices of the field. We do, at least, speak the same basic language--and as with languages, it's important to be conversant (and to converse!) if you are to study something.\n\nThe second question, which is implicit, involves disciplinarity itself. The division between a lot of disciplines as separate units is an artifact of the turn of the 20th century (or earlier), and arose from a European model of how one divided subjects and fields. That baggage of that particular nationalist moment is still with us, and most scholars are aware of the artificiality of the lines. However, if you study in certain areas that emerged after the early 20th century (such as African history) there's a tremendous amount of cross-disciplinary discussion and has been for a long time. We have borrowed very freely from linguistics, folklore, anthropology, literature, music, art, political science, medicine/public health, and so forth; for more specialized subjects, we've also been attuned to the same critical discussions going on in other fields (such as geography, for my case). That's also true for other disciplines crossing into history; I have colleagues in Anthropology who are doing amazing, deep sociocultural and spatial histories of the western Sudan, and who could easily be in our department instead. This erasure of boundaries is also increasingly visible in more established fields of history, especially as we've moved away from overarching narratives in favor of a more expansive consideration of history (e.g., \"US history\" now has many, many thematic and regional subfields with different methodological toolkits).\n\nMy short answer to your question is \"yes, there should be more cooperation and collaboration,\" but I would leaven it by saying that there is already a great deal of connection and crossing-over--perhaps more than most students of history realize!",
"The short answer is yes, there does need to be some collaboration, and indeed, that happens quite regularly. Economic historians do talk to, work with, and read the work of economists. Historians of science do have a familiarity with the science and frequently do talk to scientists (though, as /u/khosikulu notes, that usefulness may decline as one goes backwards in time — talking to a physicist _today_ about Boyle's theory of the vacuum is likely less valuable than it might seem, since they don't see the world the way Boyle did, and concluding \"Boyle was wrong according to the present day\" is not a good way of understanding Boyle). Diplomatic historians do overlap heavily with people who study international relations in the present day (and vice versa). Historians of mathematics frequently do engage with mathematicians. There are tons of overlaps — the idea that historians just hang out in their own disciplines in an Ivory Tower fashion is not true today, and may never have been true. \n\nObviously there are greater and lesser collaborations, of course. Some historians of science really do want their work to be read _by_ scientists. Most do not, and so the extent of communication is going to necessarily be mostly one-directional. Separately there are issues of authority: scientists approach history differently than historians do, and they often resent that historians of science do not defer to present-day scientists for judgments relating to science. (See the famous \"Science Wars\" incident of the 1990s.) \n\nShould there be _more_ cooperation, or is the amount of cooperation right now fine? Depends on who you ask, I suppose. But any historian worth their salt is capable of recognizing when they are wading into the expertise of another field, and capable of dipping a toe into that other expertise (even if that just means calling up someone who is an expert and talking with them — I have a plasma physicist I call up whenever I have questions about nuclear fusion, I do not pretend to fully grok the ins and outs of the science). I am not sure on what basis one would argue there should be more or less of it — I know of no great scandals at the moment regarding historians being particular out to lunch on any other field's expertise, but that isn't sufficient to declare something being \"just right.\" But each historian acts as an individual entity, and this is a very broad issue, so making a collective judgment like that strikes me as being pretty difficult."
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1knszi | Behavior of potassium chloride in cooking as salt substitute | askscience | http://www.reddit.com/r/askscience/comments/1knszi/behavior_of_potassium_chloride_in_cooking_as_salt/ | {
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" > The question is: would potassium chloride which is a common ingredient in salt substitutes have the same effect?\n\nYes. The water is drawn out as part of an [osmotic](_URL_0_) effect. Specifically in the case of onions, water can move through the onion cell wall, and is \"pulled out\" by the salt. The degree that it is \"pulled out\" is based on the number of salt ions that are outside of the onion. Technically, because potassium weighs slightly more than sodium, gram for gram, there will be less potassium ions than sodium, this means the osmotic gradient will be less when you sue potassium, but this difference would be very very slight and I doubt you'd be able to notice.\n\n > can this fake salt be a recommended source of potassium for a normal healthy person given that an average American intakes only half of the 4500 mg of recommended daily allowance of potassium?\n\nAbsolutely. Some people are be prescribed potassium pills to help with salt deficiencies (usually resulting from taking diuretics). It appears that potassium deficiency is fairly rare. If you think you have problems you should talk to your doctor/nutritionist/health professional."
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6cpzja | what exactly does brake fluid do? what makes it work more than another substance, say something like water? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6cpzja/eli5_what_exactly_does_brake_fluid_do_what_makes/ | {
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"It has a high boiling point so it does not vaporize in your brake lines like water would do.",
"Brake fluids biggest advantage is that it takes a lot of heat to boil. The liquid isn't compressible (or not nearly as much) but if it were gas it would be. It also acts as a lubricant for the breaking system.",
"The brake pedal compresses the fluid which in turn pushes on the brake pads and drums, creating friction with the spinning wheel thus slowing it down. The friction of braking creates a substantial amount of heat, and the fluid must have a high boiling point to prevent vaporizing in the hydraulics. Water would boil, creating vapor in the line that would disrupt the hydraulics, thus causing the braking system to fail. The fluid also must maintain a stable viscosity at different temperatures and not corrode parts it comes in contact with.",
"These are glycol-based hydraulic fluids that are not appreciably compressible, non-toxic, biodegradable, hydroscopic, and have extremely high boiling points. That's key for a system that converts motion into heat through friction. Your brake system can easily hit several hundred degrees, and the hydraulic system can itself rise a couple hundred degrees through conduction and radiant heat. Water will boil and turn to steam in your brake system, which becomes a compressible spring. That doesn't mean you get an additional spring force pressing on your brakes, that means you have a spring absorbing all the force you're applying to the brakes. This is a foot-to-the-floor-and-you-ain't-stopping sort of problem. This is why it's important to keep that cap on your master brake cylinder - your brake fluid will actually pull moisture out of the atmosphere. Also, don't keep bottles of old brake fluid around, they, too, can collect water from the atmosphere.",
"Now is my time to tell it how it was. My stepdad and my first new car (5mi off the lot, just a Malibu, but still) in his great genius decided that my brake fluid was low...^^because ^^he ^^drained ^^it. But, he had some power steering fluid and decided since both are \"hydraulic fluids\" that they should work interchangeably. \n\nLong story short, a month later I had to have the entire brake line system removed as the steering fluid corroded them. I've got lots of stories about his smarts. This was one of my favorites.",
"Brake fluid is basically hydraulic fluid but with several properties that make it useful in automotive braking systems. \n\nNeeds to be non corrosive\n\nNeeds to be thin enough to flow easily in small tubes but thick enough to prevent foaming or break up. \n\nNeeds to be stable at a variety of temperatures. \n\n\nWater would corrode the metal of the brake system and it would be unstable and freeze at low temperature, and might boil off or explode at high temperature. \n\nRegular motor oil would be very good at preventing corrosion or being sensitive to high temperature but it may be to thick to flow properly through small brake lines especially when cold. \n\nSo brake fluid is engineered to have these properties as well as as not attacking seals and gaskets in the reservoir. ",
"It was mentioned by others than brake fluid readily absorbs water, but it wasn't explicitly stated why. If you end up with water in your brake lines with a fluid that doesn't absorb it (like an oil) you could end up with the same boiling/freezing problems already discussed, simply on a smaller scale. By absorbing the water the brake fluid becomes slightly diluted, but can still do its job."
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97o8sn | What thermal quantity do we sense? | Obviously we can distinguish between hot or cold, but what exact physical quantity do our bodies "measure" or sense? For example, temperature, thermal capacity, heat flux, heat rate, etc.
I don't think we sense temperature, because a metal at room temperature will *feel* colder than a nonmetal at room temperature.
What thermal quantity do we sense when we touch things? | askscience | https://www.reddit.com/r/askscience/comments/97o8sn/what_thermal_quantity_do_we_sense/ | {
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"As I understand it, the thermal sensors in your nerve endings pick up change in their own temperature. So as you gain heat from touching something warm, or lose heat by touching something cold, you will sense the change in your own skin's temp. Thus, as the thermal conductivity of whatever material you're touching increases, you'll feel a corresponding increase in the rate of change. So a metal feels colder because it's pulling more heat out of your skin, and a non metal feels warmer because it is less conductive and thus pulls less heat out of your skin.\n\nVeritasium did a good video on this: \n\n_URL_0_\n\n",
"What people seem to feel is the rate at which heat is done, which would be *thermal power* (or [rate of heat flow](_URL_0_)).\n\nUnfortunately, there is a lot of confusion about \"heat\" because of the way we use the word linguistically - which stems from a time of not being sure scientifically what we were talking about. Now we have good scientific definitions of \"heat\", but language has been slow to catch up and it leads to some confusion.\n\nFor example, people talk about \"heat transfer\", or doing things like \"gaining\" or \"losing\" heat. But heat is not an intrinsic quantity - temperature is. You gain or lose temperature, but scientifically speaking you can't gain or lose heat.\n\nFrom a physical perspective, heat is very similar to work. As you noted, metal at room temperature *feels* colder because you're sensing the *rate* at which you do heat on the metal; you're sensing the *rate of change of energy flow*, which is power. The reason for this is that, all other things being equal, thermal power is greater between two objects with a larger temperature differential. So if you're touching two pieces of wood at different temperatures, say one at room temperature and one at skin temperature, you will do heat at a higher rate on the cooler piece of wood.\n\nBut thermal power is *also* greater when an object has a higher thermal conductivity, which metals do. So when you're touching wood and metal at the same temperature, you're still doing heat on both, but the metal will warm up faster owing to its higher thermal conductivity and therefore the thermal power is greater, tricking our brain into thinking there is a larger temperature differential between the metal and our skin than there is between the wood and our skin, i.e., that the metal is colder."
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24b6h5 | why does beef turn brown when it's cooked, but chicken turns white? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/24b6h5/eli5_why_does_beef_turn_brown_when_its_cooked_but/ | {
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"There is a certain molecule in meat which gives its red color, that molecule is called myoglobin. Since the molecule is found in all types of meat it is the number myoglobin molecules that differ between the meats, giving them their color variation. The white meat of chicken has under 0.05% myolglobin; pork has 0.1-0.3% myoglobin; and beef has 1.5-2.0% myoglobin. So you can see that as the amount of myoglobin in a meat gets larger the color of the meat appears redder.\n\nThe color change in meats is the re-arrangement of myoglobin molecules when heat is applied.\n\n[source] (_URL_0_)"
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3eega8 | wouldn't raising the minimum wage to $15/hour hurt small businesses? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3eega8/eli5_wouldnt_raising_the_minimum_wage_to_15hour/ | {
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"Yes. That's the main argument against raising the minimum wage. Along side \"people don't deserve that much money!\"."
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1bn9sn | How different, if at all, are modern humans from those living before the Black death? | I'm sure we've all seen the graphs of the world population over time, including a fairly noticeable dip for which the Black Death is responsible.
I am wondering (particularly) immunologically, if today's humans, or the humans when that period ended, are/were stronger than those who died. | askscience | http://www.reddit.com/r/askscience/comments/1bn9sn/how_different_if_at_all_are_modern_humans_from/ | {
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"There is one I can think of: roughly 10% of Caucasian Europeans have a genetic mutation that grants immunity/resistance to the black plague, HIV and a few other viruses.\n\nMore info: _URL_0_",
"The survival rates had very little to do with immunology. Instead, because there was no reliable cure, those who saw the coming of the disease would attempt to leave the area, which was an option afforded only to the wealthy.\n\nThe majority of the English population at this time (and, subsequently, the group most afflicted) formed the peasantry, working primarily to sustain the country through agriculture. Their class was struggling with an economic deadlock, being among the lowest and most numerous of the late-medieval social order.\n\n\"Distracted by wars, weakened by malnutrition, exhausted by his struggle to win a living from his inadequate portion of ever less fertile land, the medieval peasant was ready to succumb even before the blow had fallen.\" (Ziegler 35)\n\nThese people, living in barely adequate housing, were among the most susceptible to the plague, and proved adequate in the formation places where it could thrive. Tightly packed in huts that were more likely to be frequented by plague-bearing rats than the stone houses of the nobles, a lack of resources prevented the peasants from the most reliable defense known against the plague, which was “flight from the afflicted areas.” (135).\n\nThough it's highly debated, a number of about 1/3rd the population being wiped out is generally accepted. Unfortunately, death records from the period primarily “relate not to the mass of people but to the beneficed clergy... data relating to the peasantry [is] extremely sparse.” (Hatcher 23). The Clergy had been among the more susceptible of groups because of their role in administering final rites and hearing confessions of the dying, ultimately coming closer to the source of infection.\n\nWhile I could go on for a long time on this topic, essentially, the most important fact is that survival was in large part affected by the wealthy and their ability to pack up and move. This was not an option open to the peasantry, and there are numerous accounts of peasants parading around in their former masters clothes, gorging themselves on delicacies as they died, and even more records of priests abandoning their faith and role at the coming of the disease. This opened up a lot of possibilities for England as a new power, as roles in education, politics, and religious institutions required quick replacement, resulting in a new hodgepodge of people representing faiths less stringently selected.\n\nTL;DR - Survival, from the records we have, seems to be more a matter of wealth than of immunology.\n\n\n\n\nSources:\n\n\nHatcher, John. Plague, Population, and the English Economy 1348-1530. London: The MacMillan Press Ltd, 1977. Print.\n\n\nZiegler, Philip. The Black Death. London: Collins, 1969. Print.",
"Well for one [they didn't have overbites](_URL_0_), apparently that is a product of cutlery in the 1700s and until then, our teeth aligned properly. Crazy stuff.\n\n > Wilson’s favorite theory comes from the American physical anthropologist Charles Loring Brace, a specialist in the evolution of hominid teeth. In 1977, Brace published an article that put the age of the Western overbite at no more than two hundred and fifty years—which is to say that flatware and, with it, a significant change in how we chewed were all it took for the edge-to-edge occlusion that we inherited from the Neanderthals to be replaced by the bite we now call normal. Brace was haunted by overbites. He had long assumed them to be an incremental and selective evolutionary change that began with agriculture and the consumption of grains. But the jaws he studied, on his way to building a database on the evolution of hominid teeth—apparently the biggest in the world—changed his mind. The transformation he’d seen in those eighteenth-century-gentlemen jaws was too abrupt, and too radical, to qualify as evolution, especially given the rapidity with which it then followed the spread of flatware into the middle classes, in the nineteenth century. In 1914, in the run-up to war with Germany, a stainless-steel alloy—developed to prevent corrosion in gun barrels—went on sale in Sheffield, England. Once stainless appeared on the country’s dinner tables, the guillotine bite all but disappeared.",
"Quite often, descendents of the survivors carry an allergy to pet dander. Since rats were the alleged carrier of black death, this did two things:\n\n- plugged up your nose from pathogens while around rats (the carrier)\n\n- caused people with allergies to avoid common places of pet dander (rat breeding grounds)",
"I have sort of a follow up. In my home county the plague became infamous for wiping out whole families as the structure of peasant society at that time meant you had many relatives living together and I imagine it was similar in other places to. Has there been any study on the possible drop in human genetic diversity the plague might have caused due to this?"
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"http://www.newyorker.com/arts/critics/books/2013/03/18/130318crbo_books_kramer?currentPage=all"
],
[],
[]
] | |
2s80wi | what is the difference between frostbite and chilblains? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2s80wi/eli5_what_is_the_difference_between_frostbite_and/ | {
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"text": [
"From my experience, chillblains has more to do with damage to soft tissue from exposure to the cold while frostbite is the actual freezing of the tissue."
]
} | [] | [] | [
[]
] | ||
3z7tku | Why are there so many places around the world named after Queen Victoria, when compared with other British monarchs? | [deleted] | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3z7tku/why_are_there_so_many_places_around_the_world/ | {
"a_id": [
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"score": [
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"text": [
"Because she was the (now 2nd) longest serving monarch in English history and oversaw one of the biggest expansions in the British Empire."
]
} | [] | [] | [
[]
] | |
9m06t5 | what caused humanity to grow so quickly? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9m06t5/eli5_what_caused_humanity_to_grow_so_quickly/ | {
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"1. There's a multiplicative effect. You ever try to solve a problem and once you get over that 1 big hurdle it just comes so fast and you're able to do more with less.\n2. Population. Up till even just the 1800s diseases and plagues and even war were the balances that kept humanity in check. Now we don't really have the same kind of war, there's less casualties than like a castle siege where you lose thousands in a short period of time. Infant mortality rates were really high for so long due to not enough nutrition and other diseases. In fact a fun fact is the reason the church banned homosexuality in the first place and declared it a sin was because the population was so low that having gay relationships rather than helping procreate was considered a very evil thing to do. Because you put your own pleasure above the needs of the community. \n3. Transportation and communication - thanks to advances in communicating and traveling we are now able to share ideas with people all over the world and get different perspectives to solve problems and create tech or limit death\n\n\nFeminism in essence is only viable in a population heavy society. Feminism is designed to reduce your population so it's virtuous in a population abundance but it's a vice in a society that needs population. (i.e. birth control, abortion, gay marriage, avoiding getting pregnant for a job and career etc etc etc)",
"Food.\n\nBasically if large proportions of the population are struggling to find enough to eat they don't have any spare time to do anything other than get food or do work to earn them enough food.\n\nOnce harvests improved people could use spare time to think of new things and surplus population could work in factories rather than on the land."
]
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[],
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25oytj | how do flight attendants get paid? | I'm sitting on a flight, and apparently the flight attendant's got totally screwed and instead of being done and being able to go home, now have to work and fly to another city, stay the night there, then "deadhead" back home.
During the course of my eavesdropping, I caught keywords like "deadhead pay" and pay rate's that were some weird decimal numbers, and coverage for their hotel stay and car.
Can anyone explain like I'm five how flight attendant pay works? It sounded like they weren't even sure they would be paid for this inconvenience / situation. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/25oytj/eli5_how_do_flight_attendants_get_paid/ | {
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"My husband is a steward. It does vary by airline but he works for a contractor who flies under delta but isn't owned by delta for reasons which are hilarious. Basically his pay is by flight hour. When he is \"working\" ie the plane is doing it's magical flight he gets paid a Decent wage based on experience. While he is on the ground though if he's not at his base (the airport nearest our home) he gets paid a stipend for every hour he's not here to cover expenses (this also varies based on experience). It's only like 3 bucks for him but it usually means he can eat. He brings in about as much as me and I've been at my job 3 years and he's been doing it 18 months. \n\nWhen he started he was on 'standby' which means that he could basically be called in any time. This kind of sucked as it meant if we went out and he got the call the fun times had to end. These days he has a schedule and a line so we know when his show times are (that's what they call the work day) and so he just trundles his way in serves your drinks and pretzels and tells you how to not die in the event of an emergency not that you were listening. \n\nHe enjoys his job people aren't nearly as unruly as you think (probably because he is basically the decider on the flight. Being a twat well it was nice flying with you enjoy the flight and next time you can take the train.) \n\nHe gets to visit places he likes and has made friends in some of these cities. So it's not like he sits in his hotel waiting for his next flight. Pilots apparently have left over money a lot so they'll take their crews out for drinks after the flight (assuming they don't have to fly again within the legally noted time). \n\nTldr: flight attendant more like sky butler/decider. Pays decent. ",
"It varies by airline but most flight crew get paid an hourly rate. This hourly rate is only for when the plane has left the gate. Other time spent not actually flying they are given a Per Diem and/or a much lower hourly rate.\n\nDeadhead means that instead of ending their trips at their home base the crew has to fly somewhere else then back on standby only receiving a low deadhead pay rate. They most likely had to fly another crew's plane/trip, maybe due to weather, delays etc.\n\nIt's a tough industry, very volatile. "
]
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[],
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1c96o6 | besides moralistic arguments and nimby, what motivates people to oppose expansion of casino gambling? | Casino bills seem to have a hard time getting passed, even in places not usually known for religious/moral panic. So why do people oppose casino gambling bills so loudly? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1c96o6/eli5_besides_moralistic_arguments_and_nimby_what/ | {
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"Because Gambling is bad for people. its addictive and can ruin families. im not very against it but we don't need casinos on every corner and there are very valid reasons to oppose them. They have a bigger impact on poor people too.",
"Casinos tend to have a destructive effect on their surrounding communities. While the casino itself and the immediate area may be nice to attract gamblers, the surrounding areas tend to become slums. Part of this is due to a shift in the job market, with the new casino generally offering better paying unskilled jobs than before and causing those who can get the new jobs to leave while those who couldn't are stuck. Part of it is simply that casinos tend to attract certain types of businesses: check cashing places, pawn shops, cheap motels, strip clubs, prostitution, etc. \n\nThen there's the fact that casinos usually do not perform as promised. Atlantic City NJ is a great example: when NJ legalized slot machines and table games for Atlantic City in the 1970s, the promise was that the taxes and revenues generated by the casinos for the state would cover education costs for the entire state. In nearly 40 years, this has not happened. As gambling has been legalized in other locations and Atlantic City's revenues have fallen, it has now come to the point where the State of NJ has had to loan money to some of the casinos simply so that they can stay in business and people will not lose their jobs. What was supposed to be a cash cow for the state has now become an albatross around it's neck. And with the exception of a few blocks around the Boardwalk where the casinos are located, Atlantic City is a dangerous and dilapidated city that tourists avoid like the plague. \n\nSo TL;DR: while casinos benefit a few wealthy people who develop them and their immediate area, they generally are not as good for the entire community as they're made out to be."
]
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q5t0d | the english education system...how is it structured? | Just a curious American wondering how England's school system compares to US. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/q5t0d/eli5_the_english_education_systemhow_is_it/ | {
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"Compulsory schooling starts at age 5, or 'year 1'. Things progress year by year until 'year 6', at around age 10. These years are usually all in the same school, a 'primary school', though they don't have to. Separtely, years 1-2 are 'key stage one', and 2-6 are 'key stage two', but this is a fairly arbitrary subdivision.\n\nAfter this, children progress to secondary school, also known as high school. These tend to be larger, with multiple primary schools feeding into a single one. Things continue through years 7, 8 and 9, which marks the end of key stage three.\n\nThe next two years, 10 and 11, are for GCSEs. Students narrow down their subjects taken (though not a great deal) to around 10, consisting of a few compulsory ones (some english, maths and science) and some optional ones. I'm not sure where exactly compulsory education ends, but it's probably the end of GCSEs. It's normal for this to all take place in secondary school.\n\nAfter this, it is very common to continue in the final two years of non-university education, years 12 and 13, or ages 16 and 17. Here, the students take A-levels. Each of these is split in half, an 'AS' and 'A2' year. It's normal to take 4 AS levels and continue 3 of them to A2, though doing more (even significantly more) is not uncommon. This two year period is known as 'sixth form', and commonly takes place in special sixth form colleges separate from the previous school, though there are also plenty of secondary schools with sixth form sections and students.\n\nFinally, in the standard school system, comes university. I think there is less mixing of subjects here than in the US; the student picks a subject and applies to universities with courses in it. They get offers of acceptance based on their predicted A-level results, and must choose two to stick with (a main and backup). Once the results are in, they confirm acceptance of any offers they accepted and met the requirements for, and are off to uni. Normal courses are 3 years, or increasingly 4 years in the sciences.",
"The main difference from the US system, assuming my view of the US system is accurate (SATs at 18, relatively broad choice of courses at university/college), is that we specialise a lot earlier than you do over there, and we have a preliminary exam at 16, which determines which subjects we can take to a higher level of study. \n \n* At 16, we sit GCSEs (General Certificate of Secondary Education). They are mostly information regurgitation, and are graded from A* ('A-Star') to G, with A* to C being considered a 'level two' qualification, and D to G being 'level one', and pretty much worthless. Students tend to take GCSEs in 10 or more subjects. \n \n* At 18 we sit our A-Levels - these are the exams that universities will use to determine who will get a place on their course, and as such are the equivalent to your SATs. They are graded A* to E, plus U for ungraded (ie a fail), again with anything less than a C being deemed pretty much worthless. They're a lot more involved, with a lot more emphasis on applying the knowledge properly, reasoned argument, that sort of thing. Students tend to take either 3 or 4 subjects at A-Level. I believe that these days they start taking 4 or 5 subjects initially, and after the first year they drop 1 or 2 to focus on their stronger or favourite ones. \n \n* Our university courses are also different, in that we enroll on a specific course up front, with all of the modules we take being relevant to that course from day 1. In US language, we choose our major before we even apply for university, are offered a place specifically for that major, and we don't have minors at all. There are some courses with multiple areas of focus (Accounting with Law, Chemical Physics, History with German, that sort of thing), but again those courses are set out like that from the very start; You don't just start off doing Maths and decide to add on a few Civil Engineering units to change your degree title."
]
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y8a4b | why does alcohol stay on your breath? | I've noticed that milk, soda, and juice do not stay on your breath, why does booze? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/y8a4b/eli5_why_does_alcohol_stay_on_your_breath/ | {
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"It's partly because alcohol goes into your blood stream, and when you breathe in, the air goes into your lungs and meets with the blood, so it interacts with the alcohol in your blood stream."
]
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[]
] | |
5pp17d | Where did the ancient Greeks get the ivory for the statue of Zeus at Olympia from? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/5pp17d/where_did_the_ancient_greeks_get_the_ivory_for/ | {
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"The ivory would have come from Libya. There were still elephants in North Africa at this time.\n\nThe statue of Zeus was constructed inside the great temple at Olympia in the 430s BC. The statue was designed and built by the Athenian sculptor Pheidias, whose previous work included the famous chryselephantine (gold and ivory) statue of Athena in the Parthenon at Athens.\n\nSeveral later authors describe the statue and the effect it had on visitors to Olympia. Pausanias, who wrote a travel guide to Greece in the 2nd century AD, goes into most detail (5.11.1-2):\n\n > The god sits on a throne, and he is made of gold and ivory. On his head lies a garland which is a copy of olive shoots. In his right hand he carries a Victory, which, like the statue, is of ivory and gold; she wears a ribbon and—on her head—a garland. In the left hand of the god is a scepter, ornamented with every kind of metal, and the bird sitting on the scepter is the eagle. The sandals also of the god are of gold, as is likewise his robe. On the robe are embroidered figures of animals and the flowers of the lily.\n\n > The throne is adorned with gold and with jewels, to say nothing of ebony and ivory. Upon it are painted figures and wrought images. There are four Victories, represented as dancing women, one at each foot of the throne, and two others at the base of each foot. On each of the two front feet are set Theban children ravished by sphinxes, while under the sphinxes Apollo and Artemis are shooting down the children of Niobe.\n\nHe goes on to describe the pedestal, the screens surrounding the throne, and the temple surrounding the statue.\n\nNo ancient source explicitly tells us where the material to build the statue came from. However, since the work was created in the late 5th century BC, there is really only one possibility. The presence of the Persian Empire prevented contact between Greece and India, of which the Greeks were only dimly aware; as far as we can tell, the Greeks had no knowledge of the peoples of Sub-Saharan Africa. What they did have was an active trade network with settlements and trade partners all through the Mediterranean and the Black Sea. The gold used for the statue may have been mined on Thasos or in Thrace, but it could also have been imported from Cyprus, Kolchis (modern Georgia), or Spain. The ivory must have come from the only place that had elephants and wasn't hostile to the Greeks - namely, Libya. It is possible that the Greek settlement at Cyrene (near modern Benghazi) acted as a conduit for the trade."
]
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14uuti | Is there any sort of research going on into FTL communication? Is that even possible? | I was just reading about future space travel and colonization and such, and I got to wondering about things like internet connectivity between potential future colonies. What would the lag be between Earth and Mars, at the shortest and longest distances in the orbital intervals? This then got me wondering if there are any prospects for faster-than-light communication, and I realized I don't even know where to start looking for the answers to that question. A little help?
**edit: I *know* that according to the standard model of physics, light is the "speed limit" for the universe. I was hoping more for some insight pertaining to quantum physics - like entanglement, which seems to be instantaneous.** | askscience | http://www.reddit.com/r/askscience/comments/14uuti/is_there_any_sort_of_research_going_on_into_ftl/ | {
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"There is research into FTL travel - obviously, if it is possible to travel faster than light, it is possible to communicate FTL as well.\n\n[I discuss the current state of FTL travel in this post.](_URL_0_) While there are many obstacles both practical and theoretical, there are people currently researching the issue. \n\n**EDIT:** Before you downvote, read the post I referenced. There is significant and meaningful research into FTL travel. ",
"Currently accepted theory is that NOTHING can travel faster than light.\n\nPut another way, no information can travel faster than light (and you or your rocket ship count as \"information\").\n\nYou can get things to move faster than the speed of light (say a shadow) but you cannot use these tricks to communicate.\n\nOne would hope there is something we do not know yet which would let us get around this limitation because otherwise we are really stuck to this one rock.\n\nAs it stands now though, with boatloads of evidence, there is no FTL anything. \n\nOne can only hope there is a loophole somewhere else we are stuck on this planet and/or solar system.\n"
]
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[
"http://www.reddit.com/r/askscience/comments/103mwp/despite_the_media_reporting_nasas_claim_that_warp/c6a3xm3"
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zek6g | is there land that isn't owned? can i acquire land without buying through a real estate agent? | Does the government own the land?
How do real estate agents get the land to sell?
How could I get land from the government? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/zek6g/eli5_is_there_land_that_isnt_owned_can_i_acquire/ | {
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"Pretty much everything is either owned by someone or otherwise unavailable. \n\nThere is no requirement that you use a real estate agent for a purchase, and they are not the one selling the land. They are usually hired because the process of buying and selling land is complicated and it helps to have a professional working for you. ",
"In the United States, land that isn't owned by a private entity is deemed \"public land,\" and thus is owned by the public. However, the federal government essentially says, \"let us take care of this for you,\" so the land is held \"in trust\" by the federal government, and is primarily managed by the [Bureau of Land Management (BLM)](_URL_3_), and the [National Forest Service](_URL_0_). Other federal agencies control other portions of public land. More info on public land in the United States [here](_URL_1_).\n\nSo, land in the United States is either owned by private entity or the federal government. And the BLM does occasionally sell land, but don't count on it. [More info here](_URL_2_)",
"I would imagine that, if you bought enough rocks, gravel, and soil to raise an island outside of territorial waters, it would be your land (possibly terra nullius first, then your land by right of discovery/conquest/creation).",
"1) Yeah, pretty much. You know how Christopher Columbus showed up with a flag, planted in the ground and said \"I call dibs on America for Ferdinand and Isabella\"? That's pretty much how that works. If there's somebody already living there who's all, \"I called it first\" then you say \"oh, yeah? You and what army?\" and then you have a war and if you win you get to keep the land....or to put it in fancy diplo-speak, it now comprises a part of your sovereign territory. \n\nSince it's 2012 and all and we've pretty much explored the whole globe, basically every piece of land falls within someone's sovereign territory already. There's a number of international treaties about how far out in the water sovereign territory goes --- I don't remember the specifics, but it's maybe like 10 miles out for absolute control and a further distance for \"you can drive your boat through here if you want, but only we can fish here.\" \n\nAfter that you're in international waters --- no one country controls the whole ocean, and you can have all the monkey knife fights you want. If new land were to form via volcano or meteorite or something in international waters, you could go out and call dibs if you wanted. Other people might call it as well and then you're back to the army question, of course. \n\n3) you can get land from the government because the government decides to sell you some. In the mid-west in the mid-19th century the government was giving land away for totally free to everyone who promised to live there and build a farm. They even had no-shit, starters's gun with a pistol races on Free Land day in some territories, where everybody would line up their wagons on the border and charge off at the start to stake out the best places. \n\nNowadays, the government will occasionally sell land to private owners, though it's rarer. Far more often the sell limited rights to certain government lands --- to mine or graze cattle on or log trees from. \n\nOf course most settlers in North America didn't buy the land from the government directly --- jthey just showed up and started living on it and making stuff and growing stuff. \n\nBut if you live on any land which is part of someone's sovereign territory, that means you're ruled by that sovereign, that government. And so they can charge you taxes and send you to jail if you break the law or draft you into the army if they're fighting a war or what have you. You are subject to the laws of that land. (If the land is ruled by a king or queen instead of a democratic government, then you're technically subject to the desires of that individual person --- certain sentences in English law confine the prisoner to jail/a mad house \"until Her Majisty's pleasure be known.\") \n\n2) So, as discussed, you can own all the land you can afford within a country's sovereign territory --- it's just that it and you will be subject to the rules of that land. Real estate agents don't own land --- people who do own it call up the agent and say, \"hey, I got some land I want to sell, you know a lot of people, can you find me someone to buy it off me? I'll pay you.\" \n\nI'll add in some links later to back this up, I'm on my phone at the mo."
]
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"http://en.wikipedia.org/wiki/United_States_Forest_Service",
"http://en.wikipedia.org/wiki/Public_land#United_States",
"http://usgovinfo.about.com/od/moneymatters/a/No-Free-Or-Cheap-Government-Land.htm",
"http://en.wikipedia.org/wiki/Bureau_of_Land_Management"
],
[],
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] | |
6hicq8 | what is the difference between a 50 and 1500 dollar guitar? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6hicq8/eli5_what_is_the_difference_between_a_50_and_1500/ | {
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"literally the same difference between anything with such a discrepancy... Materials, quality of craftsmanship, quality control, skill level of those involved in crafting it, experience fine tuning the process, reputation.... No one good at anything does it for free...or cheap",
"$1450. \n\n\nJust kidding, but on a real note, I'm a drummer not a guitarist but from my experience playing instruments, instruments that cost more are generally better, there's always exceptions and depending on skill level you might never notice differences, but things like metal/wood quality, wiring quality, and craftsmanship are the major differences, many expensive instruments are often handmade as well",
"Craftsmanship - A guitar requires precision. A milimeter off one measurement and you can have fret buzz, dead frets, poor intonation, etc. Cheap guitars almost universally have poor intonation. This makes it very frustrating for a musician, but the 5 year olds these are purchased for don't give a shit. On the other hand, expensive guitars usually maintain their tuning over time, and from open string all the way up to the highest frets. \n\nSound - The quality and type of wood is important to how the guitar sounds. Cheap wood is usually very lightweight and resonates poorly. It also scratches very easily. \n\nLongetivity - Quality construction, quality wood, etc. will make a guitar that's still playable after decades. A cheap guitar will bend and warp in bad ways quickly. The weak wood is unable to maintain the tension of the strings over time. \n\nMany other reasons too. Many of these things you can find in a $500 guitar so that would be a better comparison. The difference between a $500 and $1500 is MUCH smaller than the difference between a $50 and $500. \n\nWith electric instruments you also have the added cost of electronics. Cheap pickups are the bane of inexpensive guitars. Many budget guitarists purchase a reasonably constructed guitar with shitty pickups like a Squier Strat, and then replace the pickups and have a $200 guitar that sounds like a $600 guitar. "
]
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z6jpw | How fast must a passenger plane like a Boeing go to keep "flying"? | A friend and Me are on a long trip by train and we we're talking about travelling and public transportation for that matter. Then the question turned up: How fast do planes go? If planes are supposed to fly "waiting loops" (Sorry, as a none-Native I do not know the proper term.) how big are those loops? | askscience | http://www.reddit.com/r/askscience/comments/z6jpw/how_fast_must_a_passenger_plane_like_a_boeing_go/ | {
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"It's called stall speed it is the speed at which the plane will drop, the wing surface area, lift coefficient, speed, and air density all play a factor. For a Boeing 747 it has a stall speed of around 100 knots but that can vary depending on flap configuration.",
" > Then the question turned up: How fast do planes go? \n\n_URL_0_\n\nA380 jet airliner: mach 0.90, 945 kmh\n\n > If planes are supposed to fly \"waiting loops\" (Sorry, as a none-Native I do not know the proper term.) how big are those loops?\n\nThe name is \"Holding pattern\"\n\n_URL_1_\n\nSpeeds are in that link.\n\n\"Stall speed\" for an aircraft as as jimbolauski's post."
]
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[],
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"http://en.wikipedia.org/wiki/Airbus_A380",
"http://en.wikipedia.org/wiki/Holding_%28aviation%29"
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3un509 | if things have evolved to help its survival, how come some people can be killed by something like a peanut allergy? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3un509/eli5_if_things_have_evolved_to_help_its_survival/ | {
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"People have circumvented the survival of the fittest. We have developed medical ways of ensuring survival of all people, including the ones with genetics that allow them to be killed by peanuts",
"How dangerous is a peanut allergy to people whose ancestors came from a region without peanuts? If a trait doesn't actively hinder someone's breeding potential it can be passed on indefinitely. Like how humans can't synthesize vitamin c. That never was a problem right up until we started going on long trips and packing stuff like salted meats and biscuits without any vitamin c in them. Since it was never a problem the trait persisted pretty much randomly.",
"Because of medicine. Those people should be dead, but we have this thing called pity and morals that doesn't like it when we leave people to die of their own genetics."
]
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5e1q6q | What are some good books about the early Roman Empire, particularly the Julio-Claudian dynasty? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/5e1q6q/what_are_some_good_books_about_the_early_roman/ | {
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"If you're looking for academic sources I can help a little. [Wiedemann, The Julio-Claudians, 1989](_URL_9_) is a good general overview. [Eck, The Age of Augustus, 2007](_URL_2_) is a good overview of the establishment of the Principate. For the army in this period, [Le Bohec, The Imperial Roman Army, 1989](_URL_3_) is a fairly standard text. Well-regarded books focusing on individual emperors include [Levick, Claudius, 2015?](_URL_0_) and [Seager, Tiberius, 2005](_URL_4_). In fact, I'd just check out the entire [Blackwell Ancient Lives series](_URL_8_). For more general histories of the period I'd also look at other works by major publishers such as [Potter, A Companion to the Roman Empire, 2006](_URL_6_), [Goodman, The Roman World 44 BC--AD 180, 2012](_URL_1_), etc.\n\nParticularly relevant primary sources for the Julio-Claudians are the *Annals* by Tacitus, the *Lives* of Suetonius, *Roman History* of Velleius Paterculus, and Cassius Dio, books 52-63. All of these texts are available for free on [_URL_5_](_URL_7_).\n\nUnfortunately, I cannot be of much help for non-academic texts. Of the texts above you'll notice some are pretty expensive, so there's nothing wrong with looking more closely at the cheaper ones, they're all good quality texts. If you want sources specifically to do with the Roman army then I can provide several more."
]
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"http://www.bookdepository.com/Claudius-Barbar-Levick/9780415703574?ref=grid-view",
"http://www.bookdepository.com/The-Roman-World-44-BC--AD-180-Martin-Goodman/9780415559799?ref=grid-view",
"https://www.bookdepository.com/The-Age-of-Augustus/9781405151498",
"http://www.bookdepository.com/The-Imper... | ||
68657e | why have the salaries of athletes, actors, tv personalities, musicians way outpace salaries of traditional occupations over the past 100 years? | In the peak of his career, Babe Ruth (highest paid at the time) made $80,000 a year in the 1930s which is equivalent to a little over $1 million in today's dollars. Today the highest paid baseball players make $30 million+ a year.
In 1937, the highest paid actor was Gary Cooper and he made $370,000 which is equivalent to about $6 million today. In 2016, Dwayne Johnson was the highest paid actor making $65 million in one year.
This is while the average salary (adjusted for inflation)for traditional jobs hasn't risen much in the same time frame. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/68657e/eli5_why_have_the_salaries_of_athletes_actors_tv/ | {
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"Increasingly, salaries are tied to how replaceable we are rather than anything about how hard our job is or how much work is involved. Cleaners work very hard and long hours, but you can get someone else in to take over a job immediately with little training if someone quits, so they are paid crap money. Doctors/nurses/teachers are always in high supply because they are jobs that people want to do regardless of the pay, so they don't get paid much either. \n\nCelebrities that bring in lots of money for companies because of who they are as individuals are quite hard to replace. If you don't pay Dwayne Johnson enough to do the job you can't get another Dwayne Johnson. With movies, particularly, up until around the 60s (not exactly sure) there used to be a studio system where an actor/musician/director/writer etc. would sign a contract with the movie studio and they couldn't do a film for another studio until their contract was up or the studio allowed it - it's a bit like comic book movie franchises at the moment. Because actors were contractually tied to studios they couldn't demand ridiculous salaries or threaten not to make the movie, and when there are only a handful of studios the bidding wars can't really get that high when contract renewals come around.",
"The salaries of celebrities (be it an athlete, actor, musician, etc) have outpaced those of traditional workers/employees precisely because celebrities aren't traditional workers. Celebrities attract unique attention, and that attention can be leveraged and monetized. And over time, celebrities have gotten better at leveraging that attention, and brands/companies have gotten better at profiting from it. It has, in other words, to do mainly with visibility. \n\nSomeone who is 'traditionally' employed by a company gets paid relative to the role they occupy, to what they're tasked with. An athlete might be hired and paid in a similar fashion, in theory, but the key difference is that their role, and what they're tasked with by default has an *audience*. This makes them more valuable, in a number of ways. Put simply, celebrities exhibit desirable talents and traits in a very visible way. Because these talents and traits are desirable, and often idealized, what celebrities commonly do plays upon emotions. \n\nMusicians and actors give a voice to what people are feeling, or wish they could themselves say, or how they wish they could look or behave. Athletes exercise physical and mental acuity in sports, pull off great feats, etc. And because sports have over time become popular to the point that they're tied to people's identities and dreams, they likewise act as an example of who people wish they could be. TV personalities and models and whoever else also offer a fantasy or a target for people's aspirations - how they want to look, how they want to behave, how they want to be seen, how they want to live. And on a lighter note, all of these people offer entertainment and even distraction.\n\nSo you might see how this can all be monetized. What marketing does is play into people's emotions - \"Buy (x) to be more attractive,\" \"Buy (y) to be faster\". And to attach a product which plays upon these desires to a person who epitomizes them? Doubly powerful. As for more traditional jobs, no one is idolizing a lawyer sitting in their office working on a brief. No one (or not many) people are going to want the clothes *that lawyer* is wearing, or go see a movie that lawyer is in, were they somehow, for some reason, hired for a role in a movie. \n\nWhat's interesting about today's world, though, is that we're basically seeing experiments in this. In today's world, a lawyer can start a youtube channel. A teacher can have an instagram. They can find the people who might in fact idolize them, want to be like them, live like them. I think that's great. Maybe they won't be handed a $30-mil a year contract, but they can certainly find ways to make money. There are people in all walks of life and professions making a pretty penny by way of the platforms out there, and the attention they can net. \n\nEdit: typos",
"The correct price for any product or service is the highest price the market will bear. Econ 101.\n\nAs actors/athletes/anyone stipulate that they are worth $X, and a studio/team/employer pays that, then that's the going rate.\n\nIf the movie is a runaway blockbuster, or the team wins the championship, that contract is likely to be renewed or extended. The price goes up.\n\nIf the movie flops, the player tanks, or (more often) the latest/greatest star/player is coming up and will work/play for less, out with the old, in with the new.\n\nIn the movie and sports business, the \"market\" is inflated relative to Joe Schmoe, but as long as the studio/team is making money, the price will be paid. And the staying power of a few \"stars\" (Alex Rodriguez, Jennifer Aniston) that exceed the standard curve are not indicative of the more \"rank and file\" members of the group. They are \"sure bets\" and are worth a premium. Look at the average career of an MLB/NFL/NBA/etc player, or how many \"huge\" roles an \"average\" actor had. Those \"careers\" are short, perhaps sweet.\n\nThe \"A-list\" is incredibly small, even compared to the small group of people that make it to the mainstream level. They are paid well above a \"market\" rate.",
"Athletes/celebrities/musicians are earning more today mainly because of the amount of advertising revenue that is being generated. Companies are subsidizing them because their product can be pushed better due to the amount of people watching them.\n\nAthletes(sports)/TV stars have insanely high television deals right now. TV networks pay for the rights to show the sports because they can sell commercials for those sports. Inside every stadium are tons of ads. Inside TV shows is product placement.\n\nBands/musicians are making big money off of tours and merchandise right now. But everything at the tour is typically sponsored by a company.\n\nActors/Movies- There are so many layers to the success of movies today. First you have the theater, then on demand, then premium channels and Netflix, then DVD/Blu Ray/digital sales, then maybe even television. ",
"The AVERAGE musician and actors' salaries have not decreased. It used to be that if you wanted music, you'd hire a musician. If you wanted to see acting, you'd go to a play.\n\nWhat's different is the scale and reach of all of these occupations. Instead of 200 local talk shows, you have 4-5. Instead of hiring a musician, you play stuff from Spotify. The reach of each actor, musician, TV personality has grown exponentially. It may very well be that the total amount of inflation-adjusted dollars spent on entertainment is nearly the same, but it's spent on fewer entertainment sources.",
"The TOP salaries may have outpaced other salaries, but most musicians aren't Beyoncé and most actors aren't Dwayne Johnson. The vast majority of working actors and working musicians lead lifestyles from poor to middle class. \n\nThere are Tony-winning actresses who instagram their temp job applications. There are a lot of important music artists who can barely pay for their records. Some of the top jazz and classical musicians in the world especially support themselves with teaching work. "
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3pv77p | if legalizing drugs can potentially end the war on drugs, why don't the people in charge just legalize them already? | Are they unaware?
Or
Do they want to feed the Prison Industrial Complex?
Or
Is it political suicide with all the old farts in charge? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3pv77p/eli5_if_legalizing_drugs_can_potentially_end_the/ | {
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"Well, the point of the War on Drugs is to get rid of them. Legalizing drugs is just admitting defeat.\n\nBut for real answers, drugs are widely seen as a destructive force in people's lives and while incarceration doesn't seem to help that, legalization is seen as a step in the wrong direction.\n\nPrisons are a huge component to a lot of local economies so they do carry quiet the lobbying voice. For better or worse.\n\nLegalization doesn't get rid of the black market and quite a lot of the reasons people don't like drug use is because of all the turf wars and other such nastiness that comes from black market deals. Washington's legalization of marijuana has created a very restricted system of dispensaries and taxes that make legal marijuana more expensive than street marijuana and legalizing it makes it less likely someone will be punished for purchasing from unlicensed vendors. If your goal is to get rid of the black market, then legalization needs to be very carefully pursued.",
"* not everyone agrees legalizing drugs will have a net positive effect\n* the people against drugs are very vocal and will vote against anyone who supports legalization, the people for drugs are more meh about things, and usually don't make it their primary issue\n* many politicians got elected promising to get tough on drugs\n* a lot of money for police and prisons have come from the war on drugs\n* legalizing drugs basically admits the gov't has been lying for the past 80 years"
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2cvxa9 | How much did early imperial Roman long-distance trade feed through Rome? Could Mediterranean exchange regularly bypass Rome to access other regional markets directly? | I'm curious as to how crucial a node Rome was to long distance Mediterranean trade in the early imperial era, from the Augustan to the Severan dynasty.
I know that for late Roman trade, the twin spines of Carthage-Rome and Alexandria-Constantinople were absolutely essential, but that east-west trade was at an absolute minimum. I believe this is a reflection of the increasing pattern of regionalism that began with the 3rd century crisis onward to its conclusion in the medieval successor states to the empire.
But if the early imperial days were not this way, that would presuppose (as I know some historians have proposed) that the broader early imperial Roman economy involved more exchange activity. Thus there would be more comparative advantage in production from farmers on up, which raises the possibility for beyond-regional distribution of such produced goods.
But how far a range would these beyond-regional distributions go? Alexandria was obviously as much of a hotbed in the early imperial era, but we don't have Constantinople as an alternate center, thus I'm sure their trade was primarily with Rome.
But was Rome such a necessary spoke that most trade would still need to feed through there on its way elsewhere? Were regional economies strong enough outside of Rome to provide a competitive market for products? Or did the city of Rome's consumption define all trade? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2cvxa9/how_much_did_early_imperial_roman_longdistance/ | {
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"This is a very interesting question, and I hope it sparks an interesting discussion. I'll weigh in here as I am writing my dissertation on the traffic of grain in the medieval period and have read a lot about the Roman taxation/redistribution system in preparation. Before I give my two cents, however, I want to ask a couple of questions.\n\nFirst, what do you mean by \"beyond-regional\" distribution of produced goods? Could you give an example of a hypothetical exchange of goods that fits your conception?\n\nI think your question gets at the heart of the nature of Mediterranean trade, and I want to make sure I'm following your train of thought correctly.",
"There are a number of scholars that have written about this problem. M. Rostovtzeff's *Social and Economic History of the Roman Empire* would be the place to start if you haven't looked at it already.\n\nRegarding your particular question, I think that we need to look past the central redistributive axis to see elements of \"beyond-regional,\" or inter-territorial(?) trade. Although the Emperor and his government in Rome represent the single largest apparatus for the redistribution of goods, other regions of the empire must have served as financial hubs. We can see evidence of this throughout Roman history.\n\nDuring the late republic the government had been informally importing grain through legislation the legislation of what have come to be termed *populares* politicians since the Gracchi (late second century). Rome did not, however, represent the sum of all Mediterranean commercial exchange. Caesar banked with a phoenician based in Gades (Cadiz). The Phoenicians, particularly the Carthaginians, had been developing eastern Iberia into an important commercial hub throughout for hundreds of years before the Punic wars. Cadiz was founded in the 12th century BCE. The economic development of the Iberian peninsula wouldn't have devolved into some sort of subsidiary of Rome as the empire progressed. The region would have certainly exported olives and wine to Rome, but it was also a major exporter of metals, which were used throughout the Mediterranean.\n\nOther pieces of evidence for the economic development of the western Mediterranean basin can be found in the records of the late republic. Massallia (Marseille) was founded almost as early as Rome (around 600 BCE). By the late republic, a number of Roman senators lived in exile there.\n\nWe also need to consider the eastern Mediterranean. This region must have supported a large amount of inter-territorial and extra-imperial trade before the foundation of Constantinople. Asia province was the wealthiest territory of the empire from the point that it was incorporated through much of the history of the principate. The cities of Ionia were important throughout much of classical and Hellenistic history. For evidence we need only look at the seven wonders of the Ancient World. The Mausoleum of Halicarnassus and the Temple of Dionysius at Ephesus were both built in Ionia. The region was also part of the inter-imperial trade of the Hellenistic and Imperial periods. Greek speaking polities extended from the Aegean through what is now northern Pakistan during the Hellenistic period. These polities traded with the Maurya Empire (322-185 BCE) and later the Gupta Empire (320-550 CE) and the Chinese Empire of the Han Dynasty (206 BCE-220 CE). I recently read about an archaeological find that included both silks from China and a wool tapestry from the Roman Empire here, _URL_0_. Furthermore, roman glass was an in demand product in China. All of this exchange would have taken place outside of the redistributive axes of the Roman government. Furthermore, the purple dye of the old Phoenician cities continued to be produced, and not all of that was bought and sold by an apparatus of the Roman Emperor.\n\nConstantine had a number of reasons to found a new capital. Christianity was more prevalent in the east, he had recently won a civil war and a new capital founded in his name would have been a dynamic move, but perhaps most importantly, the east was simply wealthier. The foundation of Constantinople represented the creation of an imperial hub that was located at a crucially important location that facilitated trade between the Black Sea/Romania/Balkans and the Aegean. Rather than creating a new redistributive axis from scratch, Constantine was responding to a commercial pattern that had developed for hundreds of years before the foundation of the new capital and indeed the rise of Rome.\n\nThis suggestion proposed here is supported by archaeology. The largest number of premodern shipwrecks have been dated to the principate. Not all of these were found along the route to the capital. This graph was shown to me by a friend, and I am not familiar with the dating system used to come up with this position. Regardless, I think that we need to assume that the redistributive apparatus of the Roman tax system represents a significant, but not the entirety of Roman period commerce."
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4v4n5z | Why was water unsafe to drink in the middle ages if there were wells? | To me, it seems like the water table underneath a village would be clean, or at the very least, more diluted, if the village is situated farther from a city. The same could apply to a castle.
Was it the case that people living in these places would drink water straight from a well? Did they still brew beer whenever possible, perhaps out of custom? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4v4n5z/why_was_water_unsafe_to_drink_in_the_middle_ages/ | {
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"Hi, I'll leave your specific scenario for others to tackle, but just fyi, we get posts that carry the assumption that \"people drank alcohol because water was unsafe\" all the time in this sub; here's a fairly recent thread with some good discussion:\n\n* [Is it true that people living in Europe in the middle ages drank beer to avoid getting sick from dirty water?](_URL_0_) - featuring /u/jschooltiger and /u/qweniden "
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fdhffo | Is there any organism that survives boiling water? | Boiling water is the survival go-to for making water safe before drinking it, but are there microbes, parasites, algae, or any living organism that can survive that process and possibly still pose a threat to the drinker's health?
Assuming there is some type of bacteria that grows on the edge of a volcano or some super heated place like that... is there an organism that lives in a freshwater ecosystem that can survive the extreme temperature change of boiling water?
Thanks for the info! | askscience | https://www.reddit.com/r/askscience/comments/fdhffo/is_there_any_organism_that_survives_boiling_water/ | {
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"They are called thermophiles. The ones I’m familiar with are bacteria, so, they are called thermophilic archaebacteria. You find them in undersea volcanic vents and in places like the hot springs of Yellowstone.\n\nThe most famous ones have given us enzymes that make most modern molecular biology possible in the form of polymerase chain reaction (PCR).",
"Boiling water does not, for example, neutralize the prions responsible for Creutzfeldt–Jakob disease, because 100C is not enough to destroy the protein. This is one of the reasons the disease is so dangerous - you could not prepare the cow meat in a way which would have make it safe to eat.\n\nI know this answer is a bit off the mark, because prions are not living organisms, but I'm assuming you wanted to know the answer to a more general question of whether there exists any infectious agents which survive boiling.\n\n(edit) Other posters will likely have better examples which better fit your question criteria. However at least at the time of me posting this, several extremophile organisms are mentioned, but the answers don't mention whether they specifically are also dangerous to humans."
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2jg3hl | What happens to the blood inside your body when you die? | askscience | http://www.reddit.com/r/askscience/comments/2jg3hl/what_happens_to_the_blood_inside_your_body_when/ | {
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"A condition known as lividity occurs, in which all the blood will pool towards the lowest point of the body's resting place because of gravity, and then clot. If someone was to die while laying on their back, bruising would occur on posterior aspects of the body. This can actually show if a body has been moved after death. For example, if a body was found face up with bruising on the face and stomach, it would show that the person has died face down, but was flipped around.\n\nEDIT: Forgot some words :)",
"If you have a genuine interest in this kind of thing, I highly recommend the book \"Stiff: the Curious Lives of Human Cadavers\" by Mary Roach. \n\nRoach goes into detail about the history of human dissection and embalming, what happens to the body as it is decaying, and how human bodies are used when they are donated for science – from crash test dummies to mortician or plastic surgery schools. I never knew so many crazy things happened to us after death!\n\nI rarely read nonfiction or such morbid material, but with Halloween around the corner, I figured it might be good read for the season. I'm only halfway through, and not at all disappointed. "
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4z635k | what is it called when you learn a new word and then suddenly it seems like you hear the word very often soon after learning it. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4z635k/eli5_what_is_it_called_when_you_learn_a_new_word/ | {
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"Baader-Meinhof phenomenon, also known as frequency illusion. It has more to do with a word catching your attention rather than an increase in frequency of appearance. ",
"Is it weird that my friend told me about this yesterday, and now it's turning up on here?",
"This happens with pretty much everything, not just words.\n\nA good one is when you think you're always checking the clock at the same time... You're probably just remembering a specific time more than others... \n\nAnother is called \"shroom eye\". When picking shrooms, you first see non, then someone shows you one, you look around again and BAM! Shrooms everywhere!",
"Hey man, [I made a quick video to explain it!](_URL_0_)\n\nIf you prefer reading I'll run through it here:\n\n- It's called the frequency illusion, and it's down to two psychological processes.\n\n- The first is selective attention! This kicks in when we learn a new word, concept or thing. We then subconsciously look for it!\n\n- Once we see it again, confirmation bias kicks in and it essentially reassures you that because you are constantly seeing it now it must have gained overnight popularity!\n\nHope that helped, have a great day brother.\n\nedit: I have been making ELi5 videos for the past week trying to help people out, got a few going now and I'm going to keep at it.",
"Just like this\n\nRight after I bought a new car while driving every other car I see on the road is the car I just got ",
"What I need is the opposite: what do you call it when a favorite word you've known and been using for years suddenly becomes much more popular?\n\nFor me it was ***schadenfreude***, to get pleasure from someone else's misfortune (as when I found that my HS bully had hydroplaned his beloved muscle car on a rainy day and wrapped it around a telephone pole). I usually had to explain what it meant. \n\nUntil 15 years ago when suddenly it was everywhere. ",
"It's just like when you find a rare car in GTA and then all the computer characters are driving the same car ",
"I'm well into highschool and this happens to me at least once a week. This thread just answered a lot of questions. ",
"The Baader-Meinhof Phenomenon is also the reason you should write down your goals and review them everyday. If your goal is to get a job or meet someone new, make that the first thing you think about in the morning, and throughout the day you'll take notice of potential job openings and attractive friendly people. "
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1m6ist | How was history passed down before the 19th century? | As I understand, history began taking off as an academic field in the latter half of the 19th century based on Von Ranke's empiricist approach, but how did people learn about their past before then? For example, how did people in the renaissance learn about the middle ages, how did people in the middle ages learn about the Romans, for that matter, how did the Roman's pass down their heritage?
Were there any interesting approaches developed in non western cultures, like in China, or in the Aztec or Inca empire... what about the Byzantines or Ottomans... any civilization you have knowledge of?
Did academic history exists before 200 years ago, or did everyone accept "popular history?" | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1m6ist/how_was_history_passed_down_before_the_19th/ | {
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"For China, the tradition of keeping history is quite long. The ancient Chinese recorded every thing. Part of it is integral to Chinese cultural emphasis of family and clan. Personal histories are often kept and passed down generations as extensive portions of genealogy.\n\nConsequently, there were also multiple variations of historical archives, which were used later on to compile different academic opinions of history from different points of view.\n\nFor example, many Chinese imperial court officials and even imperial concubines, kept their own private historical accounts, or local regional historical accounts.\n\nprivate unpublished accounts are often kept as family treasures, not shared. Many are later discovered unexpectedly.\n\nEven today, old family archives are being discovered all the time."
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m7yav | how do the investors in 'dragons den' quickly estimate the value of a business? | For those who don't know the show, it is a show where entrepreneurs pitch their business ideas to venture capitalists (The dragons).
It only takes the dragons a couple of questions before they decide if the business has been overvalued or not. How do they determine this? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/m7yav/eli5_how_do_the_investors_in_dragons_den_quickly/ | {
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"I'm sure some of it is experience and intuition about the investment potential. But a lot of it just by comparison to other start up companies and the market for start up capital. The whole reason people invest at that level is to get a big chunk on the company for a relatively small investment. So it isn't a scientific valuation but more subjective, like valuing a poker hand or something. ",
"I'm sure some of it is experience and intuition about the investment potential. But a lot of it just by comparison to other start up companies and the market for start up capital. The whole reason people invest at that level is to get a big chunk on the company for a relatively small investment. So it isn't a scientific valuation but more subjective, like valuing a poker hand or something. "
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1ivukb | Were there any areas in which the New World civilizations were more technologically advanced than the Old World civilizations? | So I know that the Old World had more advanced wheels, for instance, and guns. But were there any technologies that the New World was more advanced in than the Old World? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1ivukb/were_there_any_areas_in_which_the_new_world/ | {
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"There were not many technologies that the New World cultures had that Old World cultures did not. The reasons for this are complicated, and I'll refer you to the [relevant section in the FAQ](_URL_0_) for previous threads that discuss why. \n\nNevertheless, there are a few. Most of these are agricultural technologies that New World cultures invented in response to unique environmental conditions. The classic example of this would be the Maya agricultural system which was designed to farm rain forest soils. Rain forest soils only have a few cm of nutrient-rich humus and everything beneath that is essentially biologically sterile. The Maya solved this by designing agricultural technologies that mimicked the rain forest ecosystem. Nitrogen fixing and nitrogen leaching plants were planted alongside each other in ways that minimized soil degradation. Fruit-bearing trees were planted in fields to create a canopy that shaded the soil from the damaging tropical sun, and fields were allowed long fallow periods between harvests to let the soil recover. It's not like Eurasians couldn't have invented such techniques, but they didn't really need to. (Not a lot of rain forests in France.)\n\nAnother good example would be rubber. Mesoamericans invented fairly sophisticated rubber working techniques that weren't significantly improved upon until the invention of vulcanization in the 19th century. Rubber working in Mesoamerica goes back to at least 1600 BC and was heavily used by the Olmec civilization. Natural latex was extracted from the tree *Castilla elastica* and used for a variety of purposes ranging from adhesives to figurines to rubber balls for the Mesoamerican ball game. Latex is extremely brittle in its raw form, so Mesoamericans processed it by mixing it with juice from the vine *Ipomoea alba*. Heat was then applied and the mixture coagulated into a polymer which retained its shape and had a higher degree of elasticity than natural latex alone. Chemical analysis of this rubber has shown that this process both concentrates and purifies the latex and produces a cross-linking of rubber molecules similar to (but less effective than) vulcanization. This technology did not exist in Eurasia because the plants it used were indigenous to the New World. \n\nSources:\n\n* Demarest, Arthur (2005) *Ancient Maya: The Rise and Fall of a Rainforest Civilization*\n\n* Hosler, Dorothy; Sandra L. Burkett; and Michael J. Tarkanian. \"Prehistoric Polymers: Rubber Processing in Ancient Mesoamerica\" *Science,* New Series, Vol. 284, No. 5422 (Jun. 18, 1999), pp. 1988-1991.",
"Phoenix, in Arizona, had a highly developed water management system as developed by the [Hohokam](_URL_0_).\n\n > Between A.D. 450 and 1500, the Hohokam living near the Salt River adapted brilliantly to this seemingly desolate environment, refining their agriculture and water management from one generation to the next. Over more than 10 centuries, they built vast canal networks up to 22 miles long and irrigated tracts of arid land up to 70,000 acres in size. \n\n[Archaeology Magazine](_URL_1_)",
"Adding to the already good discussion about agricultural technologies, a god example from the Andes involves the Tiwanaku raised field system.\n\nAt their height the Tiwanaku culture was characterized by immense plazas where festivals or rituals of thousands of people were held. To feed the people in this area, the adjacent Lukurmata valley underwent colossal changes. The Katari River that traveled the north side of the valley into Lake Titicaca was canalized over about twenty-one *miles*, with channels taken off the river in roughly equal measure. The channels irrigated fields (*suka kollus*) that, at their low points, were just below the water table, but just above the water level at their highest.\n\nI should mention at this point that, in short, growing crops at 12,000 feet is incredibly difficult - hail can tear apart the crop, or the root systems can literally freeze in the ground, or it could just not rain more than a fraction of an inch all year. In all cases you're in bad shape. The ingenuity of the Tiwanaku raised-field system is in the water table balance - flowing water won't freeze as easily, and the crop is nourished and hydrated consistently. As a result, crop losses (as done in an experiment by Alan Kolata, who elucidated all of this information) can be limited to ten percent in dry years.\n\nOf course, it wasn't impervious - the Katari River dried up and Lake Wiñaymarka pretty much disappeared for a century around 1000 AD, eventually leading to the Tiwanaku state abandonment. But it's a pretty remarkable system of resilience to harsh altiplano conditions.\n\nSource:\n\n* Kolata, Alan (1996) *Tiwanaku and Its Hinterland: Archaeology and Paleoecology of an Andean Civilization.* Volume 1: Agroecology. Washington, DC: Smithsonian Institution Press.",
"Is anyone here conversant in boat-building technology? I assume that canoes & kayaks must have been superior in some way to have become commonplace small boat designs in Canada (and perhaps elsewhere). Comments?"
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1myrl5 | Why is dog urine so ammoniac to the point of killing grass if all they drink is water? | Come to think of it, many animals in general have "strong", yellow urine, but all they consume is water. Shouldn't their urine be quite clean, say like a humans when we drink larger amounts of water? | askscience | http://www.reddit.com/r/askscience/comments/1myrl5/why_is_dog_urine_so_ammoniac_to_the_point_of/ | {
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"The ammonia in urine comes from [protein digestion.](_URL_1_) The amine group in aminoacids is broken free and later bound to [urea](_URL_2_). Urea is the main nitrous component in urine. This urea is then extracted by the kidney and excreted. Dietary source of liquids has little to do with urine, the main concern for urea is protein in diet. Urine serves two purposes, to balance osmotic pressure (kind of means salt pressure), and to remove small amounts of blood plasma over time (including urea). The removal of small amounts of blood plasma over time acts like a filter of a pool, but instead of filtering and returning the liquid like a pool, the kidney fills the bladder to discard the fluid. The kidney does however use alot of energy to save as much salt and sugar as possible in our blood. [Notice how many times NaCl(table salt), Ca, and K, are listed](_URL_3_). \n\nIf you drink large amounts of water, your kidney filters more of the water out to conserve the osmotic balance. So in short canines excrete slightly more urea (6-20 mg/dl vs 6-25 mg/dL (average BUN numbers)) because of their protein rich diets, and you urinate clearer fluids when your blood is undersalted. \n\nMore information: [Mitchell, H. H., H. A. Shonle, and H. S. Grindley. \"The origin of the nitrates in the urine.\" Journal of Biological Chemistry 24.4 (1916): 461-490.](_URL_0_)",
"You can't really make a \"low nitrogen\" food by restricting the AA's with nitrogen containing side chains. Of these (Arg, His, Lys, Asp, Gln, Trp), Arg, His, Lys and Trp are essential in dogs (Many sources disagree on exactly which, but the principle is the same). Essential amino acids are those an animal cannot manufacture for itself from other non-essential AA's. If you restrict these above, the animal would suffer protein deficiency disorders."
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4girme | Tuesday Trivia | Journals, Logs, and Diaries | [Previous weeks' Tuesday Trivias and the complete upcoming schedule.](_URL_0_)
Today's trivia theme comes to us from /u/lady_nefertankh!
And it's another primary source theme! These trivia themes are tailor-made for displaying to us all your favorite primary sources and why you love them. So today **please share any excerpts you like from diaries, journals, logs, or other such things people wrote to themselves.**
**Next week on Tuesday Trivia:** People in history who have embarrassed their family for one reason or another, the theme is Black Sheep! | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4girme/tuesday_trivia_journals_logs_and_diaries/ | {
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"14th century Dominican nun Margaretha Ebner wasn't necessarily writing for herself, or at least just for herself. Her \"Friend of Our Lord,\" the non-monastic priest Heinrich von Nordlingen, viewed this nun and several others as specially graced by God, and urged her to record her visions and revelations for the instruction of others. (\"I was ordered to write\" is a common way that medieval and early modern women justified writing about religion, most famously Teresa of Avila, but in this case we have, amazingly, some of Heinrich's letters to Ebner).\n\nEbner's spiritual journal, available in English translation in the Classics of Western Spirituality series, is...well, actually it's pretty insufferable. She's sick, she's suffering, she perceives it as a great grace. She doesn't shower, and her fellow sisters view this as an even *greater* grace and sign of her holiness. (You do you, Middle Ages).\n\nThis bit, however, gives us wonderful and warm insight into the culture of women's spiritual and practical friendship in late medieval convents, as well as the medieval devotional practice of imitating Mary as a way to grow closer to Christ:\n\n > The sister who was close to me and who had written [to Heinrich] for me came. She said to me, 'I offered you the Child this night in a dream, and it was a living child and you took it from me with great delight and placed it against your heart and wanted to suckle it. And it puzzled me that you were not embarrassed since you are so modest!' And I heard about her dream with true joy and thought that it was given to me by the will of God, and thought I should let it be known, and wrote it all down as I had experienced it powerfully.\n\nEbner, who also records her own visions (like in the next paragraph, hehe), treats her fellow nun's dream as if it had happened to her.\n\nJust think about what that says about the world of these women nurtured by communal prayer, meals, suffering, rejoicing, *living*, day in and day out.",
"The family whose estate I researched for my undergrad thesis were the Leslies, of Castle Leslie, in northern Monaghan, Ireland. Among other things, they kept game books - purpose-printed books,\nintended to record how many of a variety of different game birds were shot on a given day, or how many fish of particular types were caught, and by whom. \n\nSome of them were personal books, which travelled with their owners to various shoots at home and in other countries, while others appear to have belonged to the estate as a whole. Occasionally, there are side notes concerning weather, observations on nature, or other details. One such comment records, in 1913:\n\n > “Note: Dynamite does not pay – fish market is only 2½d a lb”.",
"One of the features of post-1991 into Soviet history has been the emergence, and in some cases reliance on, diaries as a primary source. Unlike memoirs, long an accepted Soviet tradition, most of those dug out in the past couple decades are unpublished - typically kept by families or found in the archives. These offer a new glimpse into individuals' minds, particularly during periods of frantic social change (ie Stalinism).\n\nPersonally, I'm not a huge fan of relying too heavily on such material. The diaries that historians are naturally drawn to tend to be naturally more politically/historically concious than most. This is particularly the case in Stalin's USSR, when individuals were actively trying to rewrite their histories and personalities to conform to new Soviet expectations.\n\nOne example of the above is the case of Nikolai Ustrialov. A White emigre, Ustrialov was intoxicated with the potential of the new Russia emerging in the 1930s (\"worthy of the verses of Shakespeare, the music of a Wagner and the paintbrush of a David\"). Eventually he returned to Moscow in 1935 to take part in this grand socialist experiment, marvelling at both the old faces still to be seen and the forces rapidly reshaping the country. His diary is an almost forceful attempt to demonstrate, to himself, his loyalty to the new order. Witness an entry after listening to a radio address by Stalin:\n\n > This organising, hypnotising name - his name is a slogan; it stands for personality, a destiny dictated by logic, history and social development. The successful revolution - the Great Revolution! A nation like ours... needs clear concious, concrete leadership. And it is a stroke of fortune that we have received it, yes we need a talisman, we need Stalin, STALIN [underlined in red, with picture attached] to set the pistons, steam valves and springs in motion...\n\nAnd this from a former White officer. Ustrialov had well and truly talked himself into becoming a good Stalinist and his diary was part of this process.\n\nIronically such attempts to 'remake himself' did Ustrialov himself no good. He was arrested in 1937. His diary, seen by him as evidence of his loyalty to the Soviet project, was interpreted very differently by the NKVD. Every protestation of loyalty was taken as an insincere attempt at deception and every line of the diary pored over for ideological cracks. Ultimately Ustrialov was shot and his diary, complete with scribbled comments from the NKVD investigators, forgotten about in the archives.",
" > Ah, well, if our leaders will give us back our booze I will quarrel with no one. My entrails have been insulted with so many damnable concoctions for so many years, that I fear I may have lost the ability to appreciate good liquor — though on my pilgrimages to Mexico I find that knack unimpaired so far. I shudder when I think of the stuff I’ve put into my innards. Looking back, I find that drinking, in this country at least, has been divided more or less definitely into various epochs, in each of which a different brand of poison and hell-fire dominated the thirsts of the people. Right after prohibition came in, everybody drank a tonic known as Force, which bore a picture on its label of Samson tearing the lion — and its effect was similar; they alternated this with another tonic known as Lyko. Then followed a fruit extract period, until the companies began bringing out extracts without alcoholic content. I still recall the fervent and sincere bitter blasphemies of staunch souls who had quaffed numbers of bottles of extracts, before discovering their nonalcoholic nature. Then came the boom-days of Jamaica ginger, which exceeded all epochs before and since. I doubt not that even now the mad-houses are filled with the gibbering votaries of jake. Legislation interfered with jake, and the makers of white mule, red eye and rot-gut came into their own. Of course, these drinks had been interwoven in all the other periods. Alternating poisons were hair-tonics, wood-alcohol and canned heat. I’ve seen old soaks who apparently preferred canned heat to anything else. Then there were other tonics — Sherry Bitters, Padres Wine Elixir, Virginia Dare. Virginia Dare tastes the best — that is to say, a strong man can get it down by gagging and holding his nose. A friend of mine and I stood one rainy night in the lee of the Brown County library wall, and strove manfully to get down a bottle of Sherry Bitters. Seasoned though we were on rot-gut, we ended by throwing the bottle over the nearest fence and drifting away on the bosom of the great, silent, brooding night. Padres Wine Elixir was a favorite of mine in my younger and more unregenerate days. It is bottled in California, and is merely a cheap grade of red wine, with enough drugs in it to make it nominally a tonic. Those drugs change it from a mere low-grade wine to a demon-haunted liquor. It never hits you twice the same way, and will eventually affect your heart. Pay no attention to the amount of alcohol stamped on the label; it varies from bottle to bottle. I have drunk three bottles and gotten no more cock-eyed than I have with half a bottle on another occasion. If you keep it cold it tastes slightly better, but when it’s hot it has a more lethal kick.\n\n > And yet, when I look back over a sordid past, I find that the worst liquor I ever got hold of bore the government seal and stamp. It was prescription liquor and cost, altogether, seven and a half dollars a pint; more, it purported to be sixteen years old. It knocked me blind and kicking, and if it hadn’t been for nearly half a pint of Canadian rye whiskey I drank at the same time, I believe it would have wound my clock. The rye fought the poison in the other stuff. Separately, either might have finished me; together, one counteracted the other. Judas, will I ever forget that debauch! It was colder than hell, one Christmas. There were three of us playing seven-up by a fire in the woods. When the deuces began to look like aces, I called to mind the feat of Rob Roy’s son in driving a dirk through a board, and forthwith stabbed at the box on which we were playing, with my hunting knife. But the box was much lighter than the Highlander’s board, and knife and fist as well crashed clear through it, ruining the game. The liquor was at all of us, and one was clear wild. In the grip of the obvious hallucination that he was John L. Sullivan, he began to swing haymakers at me whenever I reeled into reach. He was six feet two in height and as broad as a barn-door; besides, he had heavy cameo rings on each hand, and these rings sunk into my flesh unpleasantly. So I avoided him and sought to go elsewhere; I must have merely revolved about the glade, because eventually I found myself back near the fire, with my misguided friend grunting and swearing as he flailed his long arms about my ears. In desperation I caught him under the heart with my right and down he went. I remember pulling him out of the fire; and then for hours I remembered nothing, while I lay blind and senseless. But I remember the dawn that broke, cold, grey, leaden — full of retching, disgust and remorse. Uggh — those drab, brittle, grey woods! When we went to the town, we found the countryside in an uproar; for while we lay drunk, the “Santa Claus” gang that had looted Southwestern banks for more than a year, had swept into Cisco, 35 miles away and in an attempt to rob the main bank, had raved into a wholesale gun-battle that strewed the streets with dead and wounded.\n\n-- Robert E. Howard to H. P. Lovecraft, 13 July 1932, *Collected Letters of Robert E. Howard* 2.382\n\nI love the letters of Robert E. Howard and H. P. Lovecraft, not just for the insight into their lives and writing, but as historical documents into the period they lived in, and the events they were witness to.\n",
"Who was Hipólito Gutiérrez?\n\nWe know that in 1879, he was 20 years old and lived in the village of Colton, close to Chillán in Chile. We know that he was literate but not educated, being able to write down his experiences on stationary that he had come over from a Peruvian sugar company and writing just as he spoke: without proper syntax, grammar and a liberal use of slang. By the time he starts writing down his experiences while in Lima, Peru in 1881, Gutiérrez had left his village as a volunteer in the Chillán regiment to fight in the War of the Pacific (1879-1883) against Peru and Bolivia, fought in three major battles, crossed the Atacama desert several times on foot (and on train) and triumphantly occupied the capital of Peru, Lima. \n\nThe final pages of his presumably posthumously published memoir, *Croníca de un soldado de la Guerra del Pacifico*, simply recites the debts he owns in money to his comrades that he had borrowed money from.\n\nWas the writing of Gutiérrez supposed to be published? Was it intended as a memoir which it was later published as in the 1950s? It was written while the war was still in progress, but it does not have the form or language of a diary. We hear nothing more from Gutiérrez after he arrives home from the war and write the final words in his memoir/recollection. I don't know how the manuscript came to be in the possession of Dr. Rodolfo Lenz who in turn handed it to Yolando Pino Saavedra who published it with annotations and with an appendix discussing its linguistic, cultural and historical significance. \n\nThe manuscript itself gives us a simple and straight-forward look into the experiences and thoughts of a volunteer soldier who had never dreamt of going to war until his country called on him. It has a tremendous significance due to its unpretentious writing and personality infused words. \n\nTake this excerpt as an example:\n\n > An officer dropped his parasol that he had been carried and the wind picked it up into the air and took it. A soldier ran after it, which was admirable, but he couldn't catch up with it. He continued until he grew tired and gave up. The parasol was white and open. We had been walking for around 2 *leguas* and we could still see the parasol.\n\nWhat does this tells us? It's humorous, but it also speaks of the fascination that Gutiérrez have of the great distances of the Atacama desert, one of the driest deserts in the world. It's his way of trying to explain just how gigantic this desert appeared to him, that despite walking so far (around 8 km/4.9 miles) from where this officer had dropped his parasol, he could still see the open white parasol drifting through the desert.\n\nWhat I like about this manuscript is that it is honest. It's almost brutally honest and personal, despite knowing nothing about this man beyond what he tells us and what he tells us is personal: That his brother was crying when Gutiérrez joined the army, that his mother cried when they left Chillán for the north, that he wished that he had never been born so as to not have to suffer those tremendous hardships while marching across the Atacama desert, that the bullets fell \"like hail\" during the battle of Tacna and he genuinely believed that \"no man will die until the time has come\", a line he comes back to time and time again throughout his less than 100 pages long manuscript.\n\nI don't know who Hipólito Gutiérrez, the farm boy turned soldier, really was. But what he has to tell us in his simple words with messed up syntax and faulty grammar is one of the most astounding and personal military experiences I've ever read.",
"Several years ago I transcribed the diary of [Florence Ranger of Glens Falls, NY, from 1879](_URL_1_) - it's a great source for everyday middle class female life. She writes about her complex social life (visiting, going to dances, being escorted, teaching Sunday school, attending clubs) and what she does at home with her family - it's very relatable.\n\n > May 31 Saturday\n\n > A dreadful hot day. over 100 in the shade by our thermometer. sewing all day until 2.30 took bath dressed went up to Miss Higbys to make the Floral Letters for the [Sunday School] celebration tomorrow short of flowers stayed till 5.30. home to supper at 6.30. Went to the first meeting of our Archery Club. eight members present we shot till 8. in Sate's yard then adjourned to Gert's & stayed till 9.30 music cards oranges & c. we shot at a range of fifteen feet. After a few shots around to try our skill we took sides. Gert K- Sate & I against Bertha, Ada & Mary Price. After three rounds of three arrows each. our side beat a score of 83 to 65 then Nan Cheney came with her six foot bow and we shot four rounds, three against four divided in this way. Gert. K. Bertha & I against the four we won with a score of 128 to 112. all like it\n\nAnother diary I transcribed was written by [Stephen DeForest Hopkins in 1858](_URL_0_) - again, a great slice of everyday life, as he was scrupulous about noting down every detail. He also documented his somewhat stymied courtship with his eventual wife, Elizabeth Hopkins. (Underlining in original is replaced with italics for Reddit.)\n\n > Sunday Sept 5th. A bright, beautiful day. Got up at 7 After breakfast came up to my room. copied some of my journal and wrote some to Lizzie. Did not go to Church this morning After the girls were gone. sat down and fussed with my foot^1. a while. then read till they came Home. When Sister came she brought me something from Lizzie. Came up to my room at 1. read what she had written. and thought over it for a time. then down stairs again. there till church time in the evening. passed the time lying on the sofa sleeping. sitting about here and there talking. & c. went to church at 7. got there early so we all sat down on the steps to wait till some one else came. before going in. Lizzie came after a while in her old place as usual. The services were *very pleasant*. Lizzie and I came out together. and down as far as the corner by Mr Phelps. Came Home. took a cigare smoked till nearly 10 then while Sister was writing a letter. talked to Mary till 11 Came up stairs and lay down at 1/2 past 11.\n\n > Have thought a *great deal* during the day and eve. of what Lizzie wrote in her journal. Felt grieved and sad when I read *how unhappy* she is. or at least. *was*. one night. I can't *bear* to think that I *could help her. that *I* could *take it away*. and in so doing make us *both happier*. There's but *one* way in which this *can* be done. *that* will bring us *both pain* at *first*. and *I know will* make *one* of us. unhappy for a *long* time to come. *God give me strength* to *do* what is *right*. and *best*. for *her happiness* let *come what will*.\n\n1. He had a foot injury that he also talked about in some entries.",
"I'm finding that the art of biography depends more heavily than I realized on an interesting feature of diaries: simple mentions of personal meetings. There's no content, just a note that a person was in a place at a given time. It adds an enormous amount of texture to portraying subjects as living, breathing people.\n\nMy favorite entry, however, comes from my research in the Avon Papers (Anthony Eden's documents). The Suez Crisis cost him his prime ministership and was a bitter end to a long life of diplomatic service, made all the worse by medical difficulties. He however blamed John Foster Dulles, the US Secretary of State, for sending him up the river. A bitter line to that effect appears in a diary entry from 1972, 15 years later, after Dulles was long dead, commemorating that sense of betrayal amongst all the notes of visiting and receiving guests. I'd give the verbatim text but alas my notes are 12000 miles away! It, too, is a reminder that our subjects are human beings, with memories and emotions that pass far beyond the moment under study."
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9sox17 | Question regarding the 1983 cold war scare | Why was Andropov and the Kremlin elite in general so paranoid in 1983 as to almost cause a nuclear war? Were they senile? I mean I get it, they went through WW2 and Barbarossa, but still. And why at that point of all times? Why were they so scared of Reagan? Why did they believe a first strike was coming? Did they not realize they would always be able to launch a massive retaliation to destroy the US, even by submarines alone? Surely they knew that. By the 1970s and 1980s there was easily MAD. Why were they scared of the Pershings? They had hundreds of SS20s as well! What else gave them their opinion that the US was planning a strike? Were they also fed false information by the Stasi or others? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/9sox17/question_regarding_the_1983_cold_war_scare/ | {
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"The specific fear that the Soviet elite had was that the US, with its vast arsenal of very fast and very accurate weapons that could be placed very close to Soviet borders, could execute a \"decapitation attack.\" That is, they believed that the US believed that it might be possible for the US to destroy their means of retaliation, first by destroying their command and control systems (e.g., killing off the Politburo, the top generals, and the means by which a nuclear \"firing signal\" might be sent), and then attacking the weapons themselves (\"counterforce\"). They also worried that the US might have the ability to detect the location of Soviet submarines and thus blunt their capability as \"second strike\" devices.\n\nIs this paranoid? The US, at the very same time, worried that the Soviets were developing the exact same capabilities. Much of Reagan's defense posture was in fact based on the idea that the Soviets had pulled vastly ahead of the US and that there were now potential \"windows of vulnerability\" where the US could imagine how it would attack itself and render its ability to respond either impotent or at the very least blunted. So if it was paranoia, it was a paranoia felt by both sides: advances in the 1970s had, in the eyes of many, destabilized the balance of power. \n\nOn Pershings vs. SS-20s — Pershings were feared as weapons that could destroy command and control. SS-20s did not serve the same aims (they could not target Washington DC and NORAD, for example, but the Pershings were feared to be able to target Moscow). So there is an imbalance there, an imbalance created by the fact that the US had nukes on the territory of allies on the borders of the USSR (like West Germany) and the Soviets did not have the reverse (the one time they tried to do this, in Cuba, led to another war scare). \n\nThe USSR brass genuinely believed that the USA was contemplating a paralyzing first strike, one that might end up with the destruction of Western Europe, and maybe some losses in the USA, but in their eyes they thought the US leadership might be anti-Soviet enough to think it worthwhile, if it also led to the destruction of the USSR. Though there had been, in the 1950s and 1960s, advocates of preemptive war in the USA, no President ever took such a thing very seriously, and in retrospect this was a totally incorrect assessment by the Soviets, reflecting a deep misunderstanding about the priorities of American Cold War Presidents (none of whom would have been willing to trade US cities, or Western Europe, for the end of the USSR). Of course the US had similar misconceptions about the designs of the Soviet Premiers, we now also know. \n\nWith this framework in mind, the KGB and Stasi sought out confirmation of their worst fears in any piece of data that they saw. Statisticians call this \"chasing noise\": when you are willing to take in any evidence for a thesis as \"positive\" evidence, no matter how small or inferential, and you do not take into account any evidence against it (because you think it is part of a conspiracy, or whatever), then you find endless confirmation for your thesis wherever you look. This is the cognitive error that underlies all conspiracy theories, but it also can enter into intelligence assessments as well, _especially_ if there are political rewards for giving the bosses what they hope to hear (which may have been the case with the Stasi). (And again, this is not unique to the USSR: consider how US intelligence on Iraq's WMD program went so wrong.)\n\nEven if Reagan had not made quasi-apocalyptic statements (that to a Soviet mind confirmed their worst fears about the influence of religion on these matters), even if Reagan had not campaigned on and then went through with the idea that the US was vastly behind the USSR and needed a vast upgrade in nuclear weapons systems, even if Reagan had not joked about starting nuclear war against the \"Evil Empire,\" even if they had not based new, fast, accurate Pershing II missiles in West Germany, even if they did not plan massive war game exercises like Able Archer right near Soviet borders, even if they didn't violate Soviet airspace repeatedly to \"test\" their reaction capabilities (which led to the shoot down of KAL007), etc. etc., you could imagine the Soviet Union, once it fell into this mindset, being very uneasy about US intentions and goals. But certainly _with_ all of those things, it is easy to see how this mindset flourished under these conditions, only to be undone by better understanding (under Gorbachev) of the US state of mind. \n\nBecause the control over the use of nuclear weapons is very tightly controlled at the top of governments, the game of guessing how they would be used becomes a very personal, even psychological one. It's relatively easy to talk in broad terms of national policy and philosophy (though even that can lend to perilous misunderstandings and generalizations), but if you're trying to characterize an individual President or Premier you run into all sorts of idiosyncrasies, personal beliefs, and even questions of psychological fitness. So it is easy, if you are in that mindset, to assume the worst case scenario. And when the consequences of being wrong or right are so high, as they are with nuclear war, then the strategists and intelligence analysts have easily found it defensible to assume the worst until you have confirmation of the alternative. \n\nHoffman's _The Dead Hand_ is a great resource for characterizing the US and USSR points of view in the early 1980s, esp. in 1983. "
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2hr63v | sleeping plants/trees | Why do certain plants/trees go in a sleeping mode (branches and leaves lower at night and come back up in the morning) and why doesn't this happen with all trees/plants? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2hr63v/eli5_sleeping_plantstrees/ | {
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"It is believed that light sensitive processes such as DNA replication benefit from occurring during the night when they are not being interfered with. By contrast it makes sense to focus more resources on processes that require light during the day. So altered activity during the day and the night is observed in many plant varieties. You should know that this is only a hypothesis and not a strongly supported one either. Ultimate causation is always difficult to pin down. At best one can say that there is no definitive proof that this hypothesis is incorrect."
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3m4i05 | Can someone explain to me why the 9/11 terrorists hated the United States? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3m4i05/can_someone_explain_to_me_why_the_911_terrorists/ | {
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"I remember bringing this point up at a Christmas discussion with family and friends in the UK. A gentleman in his seventies told me \"that may be the most obtuse thing I've ever heard\".\nI refuted, saying: their act of terrorism on the United States was to stop the funding of their enemy.\n\nHe asked me how it would stop that, and I realised I was fighting a losing battle.\n\nI'm sure if the average voter in the United States were asked: \"would you support the suspension of funding Israel in exchange for safety, security, and less government spying normal citizens?\"\nAnd the people would unanimously agree to suspend the funding..\n\nThat just doesn't line the politicians pockets very well, so it's never been put that way.\n\nWhy wasn't this in the news?\n\nWhy is it only comedians who managed to speak about this?"
]
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5wkx5k | cars like vw beetle proved that a motor can be refrigerated by air. why this kind of design never succeeded to be the most popular and water/liquid refrigerated won? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5wkx5k/eli5_cars_like_vw_beetle_proved_that_a_motor_can/ | {
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"It's more likely to overheat. If you're at a standstill or going up a steep hill with a heavy load for example it's not being cooled enough for the amount of work it's doing.",
"Liquid cooling can be used for more precise, in-block cooling.\n\nAir refrigeration is limited by the engine's geometry and is less efficient. ",
"Aircraft engines have been almost exclusively air cooled for decades.\nThe thing with a car is designers want to have a handy source of heat for doing different things like heating the interior or defrosting the windows.Coolant solves that and has the added bonus of making the car safer when it comes to exhaust fumes getting in the passenger cabin.Plus the coolant also heats up the transmission to operating temp faster with a heat exchanger and keeps it from over heating as well.(automatic). When you use the heat from an air cooled engine (either off the heads or from the manifolds) you have an increased risc of exhaust gas getting in the passenger compartment and putting you to sleep,(bad). And the gas burning heaters (vw beetles) just killed your gas mileage. ",
"Just because somethings possible doesn't mean it's a good idea. Liquid coolants have a *much* higher heat capacity, and so can absorb much higher amounts of heat from the engine. This is good, because the engine generally runs more efficiently as it's operating temperature increases, but this necessitates a better coolant system to get rid of the waste heat from the engine block, which allows you to get all of the positives of a hot engine, with none of the negatives.",
"What works in a cheap, low powered vehicle doesn't necessarily scale to more powerful vehicles that generate a lot more heat and have more complex engines."
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19280p | How does your eye focus on something so close with Google Glass? | askscience | http://www.reddit.com/r/askscience/comments/19280p/how_does_your_eye_focus_on_something_so_close/ | {
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"If it is anything like a HUD in an aircraft, the focal length would be infinity.",
"I have a [Recon Instruments HUD](_URL_0_), the way that works is with a tiny screen (like a couple of mm) and a lens to make it look as though it is larger and further away... \n\nIn other news I can go 59kmh on my snowboard... ",
"Thought Experiment: can we look at a *ultra hd screen* about 10 cm away from our eyes showing an image, and be tricked into believing the things are really far away?",
"The fact that you can't focus on something so close to your eye isn't due to some law of optics that prevents it, our eyes just physically aren't capable of changing focus enough. It's no different than being farsighted. Both can be fixed with corrective lenses, which is what Google Glass does."
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e9ir7r | how is it that deep sea creatures live in a very highly pressurized, low food, no light, low oxygen environment and "thrive." | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/e9ir7r/eli5_how_is_it_that_deep_sea_creatures_live_in_a/ | {
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"Nah. Ocean pressures are super high, but molecules are still pretty much completely indifferent. Meanwhile, these creatures evolved to basically survive off the sh~~ of the animals in shallower water, as well as the chemicals released by thermal vents."
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4wwtb2 | wi-fi channel, frequency and the alphabet at the end of 802.11. | And how do they affect the connection quality and speed from the router? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4wwtb2/eli5_wifi_channel_frequency_and_the_alphabet_at/ | {
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"When transmitting wirelessly you need to be on a frequency. 2.4 and 5.0 Ghz are the standard wireless spectrums that are available to the public to use unlicensed. \n\nEvery country will license or have their own regulations on the frequencies you can use for WiFi and how much power you can use to transmit.\n\nSo as an example, if we look at 2.4GHz spectrum the actual range is something in the neighborhood of 2.4Ghz - > 2.5Ghz. The channels are specific frequencies inside that range. As an example, channel 1 would be 2.412 GHz. Channel 6 would be 2.437GHz, etc. This allows multiple devices to communicate on the spectrum allocated without as much interference.\n\nThe \"alphabet soup\" at the end is just the different wireless standards that have been ratified. They come with different performance and features based on the standard you are using. So 802.11ac is the most current standard and has more features. For example, it allows for up to 160Mhz wide channels for more speed and allows for multiple user MIMO (multiple input/multiple output) which allows the wireless access point to send data to two devices at the same time, previously not possible. Prior to 802.11ac we had 802.11n which allowed for single user MIMO which basically means that you could use multiple antennas to send multiple data streams to a single client to increase performance. It also added additional security features.\n\n",
"The Institute of Electrical and Electronics Engineers standards committee is releasing standards for equipment so they can easily work together even if they are made by different manufacturers. The IEEE 802.11 standards is a standard for wireless local networking. This must not be confused with IEEE 802.3 which is a standard for wired networks and IEEE 802.15 which is a standard for wireless personal networking like Bluetooth. The letters at the end of the standard is numbered amendments to the standard. From time to time there is new techniques which might improve the service in some way and these new techniques needs to be standardized so different equipment can use it.\n\nThe IEEE 802.11 standard have defined different channels in different frequency ranges. Equipment needs to be tuned to the same radio frequency to work together. Modern equipment will scan through all channels to find the best one. The channels are using different radio bands that is globally assigned to such things. The most common ones are the 2.4GHz and the 5GHz ISO bands. Lower frequency will go further but with lower bandwidth, higher frequency have a greater bandwidth but does not go that far. Furthermore the 2.4GHz band is much smaller then the 5GHz band and just allows for 3 non-overlapping channels while the 5GHz band have 24 non-overlapping channels.\n\nIn short the amendments most often seen on modern equipment is IEEE 802.11a which is 5GHz up to 54Mbit/s, b which is 2.4GHz up to 54Mbit/s, n which is either frequencies and up to 150Mbit/s using two channels or 64Mbit/s and double range compared to g, ac which is 5GHz and can get up to 866Mbit/s using 8 channels. Most equipment support the previous amendments assuming they have a radio which supports the frequency band and will fall back to these if the equipment in the other end does not support the newer standards. If you see equipment supporting IEEE 802.11b/n it is usually an indication that it only have a 2.4GHz radio which might have problems in crowded environments and provide lower speed. However equipment that supports IEEE 802.11a/b/n have a 5GHz and a 2.4GHz radio which might be preferred. You might also find equipment that supports IEEE 802.11a/n that might not come with a 2.4GHz radio and can have issues over long distances, though walls or when used together with equipment that only have a 2.4GHz radio.",
"There's a lot of good information here but I think maybe they're giving you details you don't care about. \n\nThe letters at the end of the 802.11 are what \"version\" of WiFi you have. Right now AC is the most recent version but N is still very common too. \n\nNewer version routers will still be able to talk to older version devices (for example, If you have an AC router it will still be able to talk to your N laptop). \n\nNewer versions will typically be faster than older versions. When two different versions are talking to each other the speed will be whatever the slowest device is. (For example, if an AC router is talking to an N laptop, then the connection will be running at N speeds since that's the slowest device). \n\nFor most of WiFi's history the frequencies (a.k.a. channels) have been in the 2.4GHz band. However, newer WiFi routers are also able to transmit in the 5GHz band. 5GHz is a little faster and often less congested but the range suffers a little bit since the signal can't penetrate obstacles quite as easily. The difference usually isn't noticeable unless you have a big house. \n\nIt also must be noted that there's no backwards compatibility when it comes to the frequencies - if you want to use 5GHz then both your router AND your end device have to support 5GHz. If either of them lacks 5GHz support then both of them will default to 2.4GHz instead. \n\nDon't worry about overlapping channels and finding unused frequencies and all that - modern WiFi systems are smart enough to do all that for you automatically. \n\nTL;DR - Pick the highest letter you can find (AC is the newest), use 5GHz if you can (both your router AND your end device have to support it), and don't worry about specific channels because your router will handle that part for you automatically. "
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2hzmng | If looking at the sun is dangerous to your eyesight, how damaging is the sun when it's low in the horizon in the morning / evening? | During my morning commute to work there are times the sun is too low in the horizon that my car's sun visor can't block the light properly or completely. The sun is bright enough to cause discomfort but I can't exactly look away while driving. How bad is this for my eyes? | askscience | http://www.reddit.com/r/askscience/comments/2hzmng/if_looking_at_the_sun_is_dangerous_to_your/ | {
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"Not very bad. It's not nearly as damaging as staring at the sun without a windshield in between. \n\nCar windshields are excellent at blocking UV and IR light due to the layered plastic and glass sheets, so the light that comes through is mostly visible. [Richard Feynman knew about this and actually looked at an atomic bomb through a car windshield (apparently) without any eye damage.](_URL_0_)"
]
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20rqf2 | To what extent is the cliche of early 20th century leaders standing around giant maps and plotting wartime strategy accurate? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/20rqf2/to_what_extent_is_the_cliche_of_early_20th/ | {
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"Well I dont have any sources on 20th century military commanders, I can tell you that modern army commanders still use big maps and plot points and troop movements. If you're plotting movements in enemy territory, then you can't just go look at it in person. They have to look at the options they have, and a map is the best way to do that.\n\nSource: I'm in the u.s army and I work in the room commanders plan in (called a toc).",
"Somewhat related, the US Navy still uses what is called an \"Ouija Board\" (Just like the game) on its aircraft carriers, which is essentially a map of the carrier with little models to denote where aircraft are located, and colored markers (washers on the carrier I toured, the USS Carl Vinson) attached to them to denote their condition (i.e. damaged, needs fuel, ready for flight, etc). The board I saw had two levels to denote the flight deck (top surface) and hanger deck (just below that, where aircraft are stored), and was located on the flight deck level of the island (the \"tower\" that sticks out of the flight deck)\n\n[Here's an article](_URL_0_) that explains more about it, and includes a picture at the top showing the Ouija Board of CVN-69, the Dwight D. Eisenhower."
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befgqk | what is a photon, and do we know if it's made of anything smaller? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/befgqk/elif_what_is_a_photon_and_do_we_know_if_its_made/ | {
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"There was a term used when I last did physics:\n\nWavicle.\n\nI don't think it's in common parlance anymore.\n\nA photon is an elementary particle. As far as we know, there's nothing smaller than these. Protons are made up of elementary particles called quarks, an electron is an elementary particle.\n\nA photon is an elementary particle that makes up electro-magnetic radiation which includes visible light.\n\nWhen you get down to this scale of particle, they act *weird*.\n\nThe particles can be in many places at once, and in many states at once.\n\nThe most common way to explain this is through [the double slit experiment](_URL_0_).\n\nSo, what about the act of observation \"changes\" things? How does observation collapse the quantum wave form? \n\nTo \"see\" a particle like a photon or electron, you must first interact with it. This action changes the behaviour of the particle, and therefore collapses the wave form.",
"A photon is a unit of the thing that light is made of.\n\nLight interferes like a wave.\n\nLight interacts with detectors in discrete clicks like a particle.\n\nThese are facts that fit together really rather poorly, considering they are supposed to describe the same thing, but they are nonetheless both true.\n\n & #x200B;\n\nTo get more technical, The modern concept of a photon comes from applying quantum theory to the electromagnetic field (the area of physics now known as quantum optics).\n\nSimilar to atomic energy levels you will have seen in chemistry class (thanks for the background), the quantum nature of the electromagnetic field at a given frequency has equally spaced energy levels (each level corresponding to a photon's worth). Because of this, we can talk about the field being in a one-photon state, a two-photon state, a vacuum state (zero-photon ground state of the field), or a superposition of all photon-number states like coherent laser light, or in a statistical distribution of photon number states like thermal (blackbody) light.\n\n & #x200B;\n\nThe quantum electromagnetic field interferes like a wave, but at every point in time, we can calculate the probability distribution for the number of photons we will measure with an ideal photon detector. Here you may see I only talk about probabilities, but that is arguably all that all of quantum theory can provide.\n\n & #x200B;\n\nWhen I first studied quantum optics, I was surprised to learn that photons weren't so much objects by themselves (like a bowling ball), but were instead quantum states of something more fundamental: the quantum electromagnetic field. Later I heard about full quantum field theory and learned that most things we think of as elementary particles are also quantum states of underlying fields. I don't know much about quantum field theory, though.\n\n & #x200B;\n\nHope this helps :)"
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20g5j2 | Were there any notable game-fixing scandals in sports prior to the Black Sox? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/20g5j2/were_there_any_notable_gamefixing_scandals_in/ | {
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"In the 1880s and 1890s there were several major scandals that rocked the world of professional rowing. By 1900, the sport had fallen in such disrepute, it became extinct due to all of the chicanery, race fixing and dastardly cheating that went on. In 1919, that sorry series of events was within living memory of the powers to be in big league baseball. They did not want to see their sport suffer the same fate, so they came down like a ton of bricks on the Black Sox. \n_URL_0_ "
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6oqa68 | After Justinian, was there any serious plans within the Byzantine Empire to reconquer the Western Empire? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6oqa68/after_justinian_was_there_any_serious_plans/ | {
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"While both Leo I and Justinian engaged in significant efforts to reclaim lost Western territory, after Justinian the Empire simply had more pressing concerns in the east. Primarily reconquering eastern territories lost in the Islamic conquests in the 7th and 8th centuries AD. That being said, the Empire never stopped believing the territory to be rightfully theirs, and would engage in offensive campaigns to retake any lost Roman territory. The most successful example being the campaigns of Basil II, he [expanded Byzantine Roman control over much of Illyricum](_URL_1_) (also known as Dalmatia/Pannonia) which actually expanded the borders of the original [Eastern Roman Empire established in 395 AD](_URL_0_) westward into the former Western Roman Empire. Don't take the linked maps too literally, I am just trying to illustrate a general idea of limited Roman expansion westward post-Justinian. \n\n & nbsp;\n\nAs far as the Byzantine Roman's view of their lost territory, the Romans thought of the territory as rightfully theirs, but acknowledged the people were no longer Roman. I will copy a [previous answer](_URL_2_) I wrote that addresses this point:\n\n & nbsp;\n\n\nThere is a pervasive but false understanding that the Byzantine Roman Empire only fought defensive wars. That the Empire was at such a progressed state of decay that it lacked the ability to mount offensives outside of its borders. While this is true in some periods when the strength of the Empire waned, there are just as many periods when the Empire was strong and sought to reclaim what had been lost. \n\n & nbsp;\n\nOne of the most successful periods of late Roman expansion in the east was in the late 10th century under the command of Emperor Nikephoros II Phokas. Nikephoros made many successful incursions into modern day Syria against the Hamdanids, an Arab Kingdom present in the region and ruling from Mosul. In the Praecepta militaria written by Nikephoros he gives us a wealth of knowledge and insight on Roman tactics of the time. However, we can also gain understanding of how he viewed the regions he was invading. \n\n > \tOn your way through hostile territory you should set fire to the regions and their settlements and burn the dwellings, the crops, and the pastures. In the place where you intend to return and rest the army, however, do not burn the pastures and the grain, but guard these very closely so that the host will find food for itself and the horses. \n\t\nNote that Nikephoros does not mention attempting to win over the native population, this is hostile territory meant to be conquered, not liberated. These regions had been under Arab Muslim rule for almost 300 years at this point, and even prior to that the Christian population of the Levant and Africa was primarily Monophysite and largely hostile to Roman (Orthodox Christian) rule. \n\nNikephoros also mentions the following regarding sieges,\n\n > \tFor the enemy, oppressed by lack of provisions, send to the inner regions of Syria and to the towns and communities, and proclaim to the faithful in the mosques and calamities which have befallen them and the pain of starvation oppressing them. They tell them such things as, should our fortress fall into the hands of the Romans, it will be the ruin of all the lands of the Saracens,\" whereupon the Saracens rise to the defense of their brethren and their faith. \n\nAgain we see the Nikephoros views the entire population as hostile, not former Roman subjects waiting for salvation. Despite this, Nikephoros still desires to conquer these lands. We don't know whether this is due to some attempt to restore the former borders of the Empire, or merely adjacent territory that was vulnerable. \n\n & nbsp;\n\t\nThe Hamdanid Emir, Sayf al-Dawla, lost dominions relentlessly before the continuous waves of Roman invaders who isolated and captured the principal strongholds of Cilicia (Adana, Mopsuestia, and Tarsos) and then went on to seize control of northern Syria. In his 966 campaign Nikephoros' armies moved unmolested between Aleppo and Antioch, showing the weak state of Hamdanid resistance. Nikephoros rebuffed Sayf al Dawla's desperate offer of tribute by naming half of Syria as his price for a truce. The death of the Hamdanid Emir the next year was followed by the fall of Antioch in 969 and vassalization of his kingdom to the Romans. \n\n & nbsp;\n\nThe next period of Roman expansion was performed under Basil II who died in 1025. Basil's primary focus was westward (how he earned his name \"The Bulgar Slayer\"), and at the time of his death, the Empire was in an extremely strong position. While geographically smaller than during Justinian's reign, the empire was compact and not spread out over distant and indefensible holding across the Mediterranean. Where Justinian was dealing with internal religions conflict, Basil's Empire was united under one cohesive faith. Where Justinian had to contend with a strong and confrontational Sassanian empire in the east, Basil's reign saw a weak Buyid dynasty struggling with internal religious strife. Unfortunately for Basil's successors, a new thread burst from the east in the form of newly converted horsemen from the Turkic clans. The Turkic clans coalesced into what we remember them as today, the Seljuks. Not even a coherent power in 1025, within thirty years they had carved out a vast kingdom containing much of modern day Iraq, Iran and Uzbekistan. Seljuk and Roman forces collided at Mantzikert in 1071, leading to a crushing Roman defeat and almost completely undoing the gains of the previous one hundred years. \n\n & nbsp;\n\nAfter Basil, the next expansion comes during the Komnenian restoration, starting with Alexios I Komnenos who came to power in 1081. In 1095 Alexios sent his ambassadors to Pope Urban II at the Council of Piacenza, leading to the First (and subsequent) Crusades. Several of Alexios' goals are clear as laid out in the Alexiad. He is focused on recovering former Roman lands to the empire, and has the Crusaders swear oaths to do so. \n\nOn the Oath:\n\n > \tIn consequence Godfrey shortly afterwards yielded to the Emperor's wish. He went to the Emperor and swore the oath which was required of him, namely, that whatever towns, countries or forts he managed to take which had formerly belonged to the Roman Empire, he would deliver up to the Governor expressly sent by the Emperor for this purpose\n > \n\nIntentions of the Crusaders:\n\n > \tAs [Bohemund] did not wish to cede Antioch to Taticius according to the oath he had previously sworn to the Emperor, but rather longed for it for himself, Bohemund planned a wicked plan which would force Taticius to remove himself from the city against his will. \n\nAlexios Learning of the Crusader's deceptions:\n\n > \tSoon the Emperor learnt of the seizure of Laodicea by Tancred, and therefore sent a letter to Bohemund which ran as follows: \"You know the oaths and promises which not only you but all the Counts took to the Roman Empire. Now you were the first to break them, by retaining possession of Antioch, and then taking more fortresses and even Laodicea itself. Therefore withdraw from Antioch and all the other cities and do what is just and right, and do not provoke more wars and troubles for yourself.\"\n\nThe result of the First 3 crusades was mixed but did allow the Romans to recover many lost parts of Anatolia. \n\n & nbsp;\n\nThe last attempt to recapture lost Asian territory was Manuel I's attempt to recapture the interior of the Anatolia. In 1176, Manuel led his forces to strike the Seljuk capitol of Iconium (in central Turkey). Manuel's forces were moving through a mountain pass on September 17, 1176 when they were ambushed by the Seljuks and defeated decisively. This battle is known as the battle of Myriokephalon, or \"ten thousand peaks\". While the defeat was not as severe as that suffered in 1071 at Mantzikert, this sapped all initiative from the Roman forces. The situation eventually worsened until the sack of Constantinople in 1204 which ended effective Roman rule. While the empire had been able to recover from calamities before, the loss and sacking of Constantinople proved too great. Although the fall of Constantinople would not come for more than two hundred years, those who still called themselves Roman would exist only in the shadows of their former greatness. \n\n & nbsp;\n\nBased on this, it is my opinion that the Byzantine or Romans as they called themselves never gave up trying to reconquer the lost territory of the Empire. Whenever the empire had the strength to do so, they moved against those who occupied their lost lands. However, they may have considered the territory of Africa and the Levant lost to the Arabs in terms of religion and culture, knowing that they would arrive as conquerors and not liberators. \n\n & nbsp;\n\n**Sources:**\n\n*Praecepta militaria* Nikephoros II Phokas\n\n*Taktika* Nikephoros Ouranos\n\n*Alexiad* Anna Komnene\n\n*Sowing the Dragon's Teeth* Eric McGeer\n\n*The Grand Strategy of the Byzantine Empire* Edward N. Luttwack\n"
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7p6lrc | how can surgeries be painful? you are in anesthesia the whole time so why do people call some surgeries painful? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7p6lrc/eli5_how_can_surgeries_be_painful_you_are_in/ | {
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"It's generally the healing process that hurts\nIt takes longer to heal than the amount of time that the anaesthesia covers.\nAlso, certain operations cannot fully be anaesthetised for. Taking out an abscessed tooth for example",
"I got the dreaded Vasectomy several years ago and I don't think the doc did a very good job numbing the area before the procedure started.\n\nThat said I did learn that, when properly motivated, I can walk backwards using my ass cheeks and it is humanly possible to vacuum seal yourself to an operating table. ;) \n\n"
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lbs16 | how do the 1% influence politics? | From my understanding, they pay very good lobbyists lots of money to promote their agendas. Is this true? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/lbs16/eli5_how_do_the_1_influence_politics/ | {
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"Yes, it's true … but it's unwise to draw conclusions from that fact in isolation, because it's only part of the picture.\n\nLobbying is nothing more than participating in representative government. Any private citizen can do it; just call your Congressional representatives' offices or visit them for an in-person meeting. You sit down and explain your point of view, and try to persuade the representative to agree with you. It's really very simple.\n\nA lobbyist is someone who's *good at that.* Just like some people are naturally talented at singing or painting or swimming, some people are just naturally talented at communication and persuasion. Others work hard over many years to *get* good at doing that. Sometimes people who are good at it choose to become professional lobbyists: that is, people who will argue a particular case or point of view to elected representatives on behalf of others.\n\n*Anybody* can hire a lobbyist … or at least attempt to. Lobbyists, for obvious reasons, are not inclined to take on clients whose positions they can't effectively support. For example, if you wanted to persuade members of Congress that babies should be slaughtered for meat and leather, you'd have a hard time finding a lobbyist who'd help you. But in general, anybody with a non-crazy argument to make can hire a lobbyist to help them communicate that argument to the right people.\n\nIn fact, you don't even have to *hire* a lobbyist, strictly speaking. There are more than 10,000 full-time professional lobbyists in Washington DC (and of course many more in the various state capitals), and virtually all of them do *at least some* pro bono work. That is to say, they'll choose to take on a particular client for free, simply because they think that client's got a good argument to make … or indeed, sometimes because it benefits that lobbyist in some intangible way to be seen making that argument. For instance, a lobbyist might choose to take a particular client pro bono if it will give that lobbyist a chance to meet with and establish relationships with members of Congress with whom the lobbyist had not previously interacted. But the upshot is the same: The lobbyist works for free.\n\nAnd of course, again, a lobbyist isn't doing anything *you yourself* couldn't do. The only difference is that lobbyists have practiced at it and gotten good.\n\nSo as you can see, it's a more nuanced topic than simply \"rich people run the country.\"\n\nImagine, just for sake of illustration, that we didn't have a Congress, and everybody in the country got to vote directly on every topic that came up. Imagine further that not only did each person get a vote, but each *organization* got a vote as well: each company, each non-profit, each church, each school, everything.\n\nAnd imagine further that a whole bunch of Americans — ten *million* of them — simply chose not to vote. They just can't be bothered, or what have you. And because of that, some proposal passed in a general election because 500 individual people voted against it, and 501 *companies* voted *for* it.\n\nHow would you react to the ten million people who claimed that the system was broken because companies got more of a vote than citizens did?\n\nObviously you'd scoff at them. If those people had simply *participated* rather than opting out of the process, the result of the general election would've been 10,000,000 to 501 … not even close.\n\nThat's the story behind the \"the 1% run the country\" meme. It's not true. What's true is that the process is open to all; we're all practically *begged* to participate at every opportunity. Many, many people simply choose not to bother, or choose not to put in the effort required to do it usefully. And then they complain that only a few have a voice in the public debate. In fact what's really going on is that *everybody* has a voice, but some people have just chosen to remain silent and gripe about things after the fact.",
"Forget the lobbyists. Here's how the 1% control America: they tell *us*, the voters, what to vote for. We do what they say.\n\nFor example: the 1% want us to dismantle the unions, because the key battleground between the 1% and the 99% is the salary-negotiating table. At that table, the unions take the side of the 99%. So the 1% want the unions gone.\n\nSo the 1% rev up their radio stations, and they tell us the unions are bad. They invent some story about unions destroying jobs, or about them causing inflation, or whatever. They send their personalities on TV, who seriously rub their chins and talk in deep, serious-sounding voices about how the unions have sapped America's productivity, devalued its currency, sent jobs overseas, or caused leprosy. And we dutifully respond by voting for union-busting politicians.\n\nThere's always a grain of truth in what they say: they find a story about some union that abused its power, which is easy to do, since all human institutions - corporate, union, or government - abuse power. They pound that story over and over.\n\nSo forget the lobbyists, forget the politicians. The problem is us. We need to stop relying on 1%-controlled media for all of our political information, and we need to do some *real* studying, learn some macroeconomics, and find out how the world really works.\n",
"Yes, it's true … but it's unwise to draw conclusions from that fact in isolation, because it's only part of the picture.\n\nLobbying is nothing more than participating in representative government. Any private citizen can do it; just call your Congressional representatives' offices or visit them for an in-person meeting. You sit down and explain your point of view, and try to persuade the representative to agree with you. It's really very simple.\n\nA lobbyist is someone who's *good at that.* Just like some people are naturally talented at singing or painting or swimming, some people are just naturally talented at communication and persuasion. Others work hard over many years to *get* good at doing that. Sometimes people who are good at it choose to become professional lobbyists: that is, people who will argue a particular case or point of view to elected representatives on behalf of others.\n\n*Anybody* can hire a lobbyist … or at least attempt to. Lobbyists, for obvious reasons, are not inclined to take on clients whose positions they can't effectively support. For example, if you wanted to persuade members of Congress that babies should be slaughtered for meat and leather, you'd have a hard time finding a lobbyist who'd help you. But in general, anybody with a non-crazy argument to make can hire a lobbyist to help them communicate that argument to the right people.\n\nIn fact, you don't even have to *hire* a lobbyist, strictly speaking. There are more than 10,000 full-time professional lobbyists in Washington DC (and of course many more in the various state capitals), and virtually all of them do *at least some* pro bono work. That is to say, they'll choose to take on a particular client for free, simply because they think that client's got a good argument to make … or indeed, sometimes because it benefits that lobbyist in some intangible way to be seen making that argument. For instance, a lobbyist might choose to take a particular client pro bono if it will give that lobbyist a chance to meet with and establish relationships with members of Congress with whom the lobbyist had not previously interacted. But the upshot is the same: The lobbyist works for free.\n\nAnd of course, again, a lobbyist isn't doing anything *you yourself* couldn't do. The only difference is that lobbyists have practiced at it and gotten good.\n\nSo as you can see, it's a more nuanced topic than simply \"rich people run the country.\"\n\nImagine, just for sake of illustration, that we didn't have a Congress, and everybody in the country got to vote directly on every topic that came up. Imagine further that not only did each person get a vote, but each *organization* got a vote as well: each company, each non-profit, each church, each school, everything.\n\nAnd imagine further that a whole bunch of Americans — ten *million* of them — simply chose not to vote. They just can't be bothered, or what have you. And because of that, some proposal passed in a general election because 500 individual people voted against it, and 501 *companies* voted *for* it.\n\nHow would you react to the ten million people who claimed that the system was broken because companies got more of a vote than citizens did?\n\nObviously you'd scoff at them. If those people had simply *participated* rather than opting out of the process, the result of the general election would've been 10,000,000 to 501 … not even close.\n\nThat's the story behind the \"the 1% run the country\" meme. It's not true. What's true is that the process is open to all; we're all practically *begged* to participate at every opportunity. Many, many people simply choose not to bother, or choose not to put in the effort required to do it usefully. And then they complain that only a few have a voice in the public debate. In fact what's really going on is that *everybody* has a voice, but some people have just chosen to remain silent and gripe about things after the fact.",
"Forget the lobbyists. Here's how the 1% control America: they tell *us*, the voters, what to vote for. We do what they say.\n\nFor example: the 1% want us to dismantle the unions, because the key battleground between the 1% and the 99% is the salary-negotiating table. At that table, the unions take the side of the 99%. So the 1% want the unions gone.\n\nSo the 1% rev up their radio stations, and they tell us the unions are bad. They invent some story about unions destroying jobs, or about them causing inflation, or whatever. They send their personalities on TV, who seriously rub their chins and talk in deep, serious-sounding voices about how the unions have sapped America's productivity, devalued its currency, sent jobs overseas, or caused leprosy. And we dutifully respond by voting for union-busting politicians.\n\nThere's always a grain of truth in what they say: they find a story about some union that abused its power, which is easy to do, since all human institutions - corporate, union, or government - abuse power. They pound that story over and over.\n\nSo forget the lobbyists, forget the politicians. The problem is us. We need to stop relying on 1%-controlled media for all of our political information, and we need to do some *real* studying, learn some macroeconomics, and find out how the world really works.\n"
]
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5mcmua | i imagine that if i were in a position of power i'd be so overwhelmed with my opportunity to serve the people that it'd be all i could think about. how is it that seemingly every politician becomes self serving by the time they reach power? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5mcmua/eli5_i_imagine_that_if_i_were_in_a_position_of/ | {
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"Because they cannot get to that position in the first place without being self serving, at least to some degree. Fully altruistic people never survive in politics long enough to get to any high ranks. Now there are a lot of politicians who have a large dose of altruism, but even these have problems getting to high ranks. ",
"Well, you could make some cynical comment about only self-serving people wanting and getting into power in the first place.\n\nA different way to look at things would involve look at just how much power a leader really has. Most people in positions of power are only there because of the people who support them. Even the greatest autocratic dictators is beholden to his supporters. they have to keep the people who keep them in power happy.\n\nBy the time anybody reaches the top they have so many strings attached to them that even the most idealistic person will be forced to do all sorts of corrupt and underhand things just to stay in power.\n\nYou can't get into power and you can't stay there without being at least slightly corrupt even in a democracy.\n\nPower corrupts. That much is true.\n\nHowever the process of attaining power also corrupts just as much as the power itself will."
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cw3r1x | in a city, how are addresses assigned when a new skyscraper or apartment building is constructed? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cw3r1x/eli5_in_a_city_how_are_addresses_assigned_when_a/ | {
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"In most cities the building itself has an address that corresponds to the lot it was built on. You don't have to worry about changing the address because it just uses the same address as whatever was built there before it. From there each apartment has it's own designation.\n\nSo if you live on the 5th floor of a building your address might be something like 1234 Market Street, Apartment 5B",
"Most cities pre-allocate all the numbers for buildings based on the land, in a city it's common to allocate a block of 100 numbers to a block. A large skyscraper gets one of those numbers. \n\nApartments within the building just specify their apartment number within the building on the address. So if the building is 195 Broadway, and you live in apartment C on floor 16, you'd address mail as \"195 Broadway Apt 16C\"",
"Cities have some sort of rule for addresses, including 0/0 axis point, how far each increment is, etc.\n\nFor example, here in Chicago State/Madison in downtown in the 0/0 mark, and all addresses are noted East or West, North or South relative to that location. And each city block (1/8 mi) is 100 increments... so you'd instandly know that a street that runs 1600 North is 2 mi. from the 0/0 point, and a street that's 4000 West is 5 miles west of that point. \n\nAs such, each block has a narrow range of possible addresses it can have and since there are typically only 1 or 2 large buildings on a block, There are a number of viable options but they are often kept simple with 100 increments or repeating numbers, like 500 W. Madison St. or 444 N. Michigan."
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c50d2p | What would someone have to have done (or been accused of doing) to be killed for witchcraft in Medieval England? | Hi there, I’m very curious about the historical side of witch trials, and I’m wondering if basically there were any specific activities or actions which would get you tried for it in Early Medieval England (around 1000 or so). I’m also curious about the process of being tried for witchcraft, if anyone is able to shed a little light on it. Thanks so much! | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/c50d2p/what_would_someone_have_to_have_done_or_been/ | {
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"Have a birthmark, a mole gossip, basically it could be anybody with whom somebody had a grudge with. Remember there were no hospitals, doctors modern medicine. They used what nature provided, the old and wise women of the village were equivalent to a modern herbalist."
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1j634k | am i allowed to produce and sell merchandise with nfl team logos and names? | I want to make my own snap backs and use NFL teams on them. For example: One would say Broncos across the cap with their logo. Is that legal to sell without a license? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1j634k/eli5_am_i_allowed_to_produce_and_sell_merchandise/ | {
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"Absolutely not. The NFL is a trademarked organization. You would be using their trademarked brand to make money for yourself, and they could sue you for:\n\n1\\. Cease and Desist of production\n\nand\n\n2\\. Every dollar you made from your merchandise\n\n",
"No, because those names and pictures belong to them, and you have to ask if you can use them. People pay lots of money to the NFL to use those names and pictures, and usually get to be the only company allowed to use them for a specific type of thing. For you to pay enough for YOU to be that company costs probably a lot more than you have in your piggy-bank.",
" > Is that legal to sell without a license? \n\nThe fact that you knew that the NFL logos were governed by licensing agreements indicates you probably already knew the answer to your question. I'm not sure why you asked it. \n\nIf you were asking if you could make one for your personal use, then yes, that's fine. But you said you wanted to *sell* them. How many people are we talking about? Selling them at your high school? That might be okay. It's not legal, but they're not going to move heaven and earth to stop you. "
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169w2h | A question about the raising of the flag on Iwo Jima and it's symbolism. | Everybody recognizes that [one] (_URL_0_) picture of the flag raising of Iwo Jima. Can any of you maybe elaborate on the consequences of this photograph. What symbolism made this photograph so amazing and how did the government use this photograph? We in Holland are covering the subject of WW2 right now but we only talked about this photograph very shortly and I think there is much more to it so if it would be a very big help if somebody could elaborate and explain.
| AskHistorians | http://www.reddit.com/r/AskHistorians/comments/169w2h/a_question_about_the_raising_of_the_flag_on_iwo/ | {
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"The picture is simply iconic, and what makes it iconic is not really a question for a historian. [Here is a link that includes a critique by a notable photographer.](_URL_1_)\n\n > As a photograph, it derives its power from a simple, dynamic composition, a sense of momentum and the kinetic energy of six men straining toward a common goal, which for one man has slipped just out of grasp. \"It has every element. ... It has everything,\" marveled Eddie Adams, a former AP photographer who took another picture that helped sum up a war — one of a South Vietnamese police chief executing a suspect.\n\n > Of Rosenthal's picture, he added: \"It's perfect: The position, the body language. ... You couldn't set anything up like this — it's just so perfect.\"\n\nA Google search for \"Raising the Flag on Iwo Jima composition\" produces a lot of hits, some of which might provide more insight into why the photo is iconic.\n\nThe details of the flag raising itself are only interesting if you accept that the photograph is special for itself, but they've been talked to death on Reddit (there's some conspiracy stuff regarding whether the photo was staged that seems to be resolvable) and it doesn't sound like you need that.\n\n[This part of the wiki article is interesting.](_URL_0_) \"Upon seeing it, Associated Press (AP) photo editor John Bodkin exclaimed 'Here's one for all time!'\" He recognized that the picture was iconic and it was immediately widely published, and won a Pulitzer.\n\nThe people in the photo were used in war bond drive, the image inspired the Marine Corps war memorial, there's been a movie made about the event and the war bond drive, and it's been on a stamp.\n\nBut the reason is that the photo is striking. There are lots of photos of war, and some of them are special, including that one.\n"
]
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"http://imgur.com/LzBke"
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"http://en.wikipedia.org/wiki/Raising_the_Flag_on_Iwo_Jima#Publication_and_staging_confusion",
"http://www.paulrother.com/IwoJima/JR50YearsLater.html"
]
] | |
2a5ib0 | [Indian History] Is there any historical evidence of Hindu dissent during Mughal rule in India? | So during the Muslim invasion and subsequent rule of India, there are several instances of [persecution of Hindus](_URL_0_)
It is also known that Hindus who resided within the Mughal empire were treated like second class citizens, and did not have equal rights as Muslims (This seems to be the main reason a lot of Hindus converted to Islam during this period).
While there were notable examples of opponents to the Mughal empire, most notably the Marathas, all challenges to Mughal rule came from the outside. I'm wondering whether there is any evidence to suggest Hindus within the Mughal empire (Who were still the majority of the population) dissented or challenged the Muslim rule.
Thanks in advance, hope my question wasn't too obscure! | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2a5ib0/indian_history_is_there_any_historical_evidence/ | {
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"So I know this is a bit odd, since this question is a month old, but since it doesn't have any answers I figured I'd give it a shot. \n\nMughal treatment of non Muslims, such as Hindus, Sikhs, Jains etc... Has three phases. Under the first two emperors the Mughals acted as your standard, run of the mill Islamic conquerors. With heavy taxes and prohibitions on non Muslims, the Mughals later became far more tolerant under Akbar and his successors. Finally, the third phase in which the Mughals reverted back to harsh policies towards their non Muslim subjects; this process started under Shah Jahan and continued until the fall of the Empire. \n\nThe Mughals did face serious dissent from Hindus under their rule. Akbar the great, who ruled the Mughal state from 1556 to 1605, brought a large amount of Hindus under his control through conquest of new lands in Central India. But unlike later Mughal emperors, Akbar too a conciliatory approach to the Hindus. He, despite being illiterate, was a huge fan of theology, and any sort of academic work. He would host great debates between various religious figures at his court and would even invite Christians and Hindus to come and lecture him. Where as the earlier Mughal emperors (Babur and Humayun) had instituted the Jizya tax (a tax on non Muslims) Akbar abolished it in 1563. Akbar also granted Hindus and other non Muslim groups the ability to repair temples and build new ones if they wanted. Taxes on Hindu pilgrims were abolished. He even allowed Hindus who had been forcibly converted to Islam to reconvert back to Hinduism without any penalty (the usual penalty for this crime would have been death). Akbar even began to celebrate the very important Hindu festivals like the Diwali. So this had the effect of binding Hindus to the Empire and Hindus, specifically Rajputs became valuable servants of the Empire. Akbar actually created his own quasi-religion which in a way merged Hinduism and Islam. Called Din-e Ilahi, the religion was intended to become widespread and bind his subjects together permanently to ensure religious squabbles would not dominate his empire. Hindus became an integral part of the Empire and thus dissent from Hindu subjects was almost non existent. \n\n\nWhile Akbar's son and successor, Jahangir would generally continue the policies of his father, Jahangir's son Shah Jahan would not. Shah Jahan was an orthodox Muslim and reversed many of the changes made by Akbar. Jahan made it illegal for Hindus to rebuild or repair temples, and he tore down all recently built Hindu temples and structures. He mandated a strict adherence to the principles of Sharia, which grated both Hindu nobles and Hindu commoners. While this is a relatively mild step, it was the first signs of the weakening of the relationship between the Mughals and their Hindu subjects. But there was no open dissent just yet.\n\nRelations took an even bigger hit under Jahan's successor, Aurangzeb. Aurangzeb was an even more radical than his predecessor. His goal was to turn the Mughal state into a proper Muslim empire. He made Islamic law the highest law in the state, and Muslim officials and aristocracy gained massive amounts of power. Hindu nobles and the Hindu subjects were angered by this, because the Muslim officials (Ulema) were seen as very corrupt and self-serving. New edicts were issued that targeted non Muslims, massive Hindu temples that were considered sacred were pulled down. Muslim governors were told to replace Hindu administrators with Muslim ones. He instituted a \"religious police\" force called the Qazi, they terrorized non Muslim communities. This is where Hindu dissent starts to come in (sorry for taking so long to get here :/), Hindu traders in the important port of Surat in Western India began a mass migration after the Qazi forcibly circumcised a Hindu working as a clerk. The traders were important to the Mughal economy (Surat was the principle port in Western India in this time). They took refuge with a Hindu prefect in the city of Ahmadabad. They only returned after the Emperor promised to keep the Qazi inline and promised to protect their religious freedom. Aurangzeb was not done there, in 1679 he revived the Jizya, the tax on non Muslims. This caused riots in many cities. In Delhi thousands of Hindus flocked to the Imperial palace demanding the tax be revoked. Aurangzeb followed this up with policies aimed at his Rajput nobles. Eventually this culminated in a small rebellion by some Rajput nobles who felt the Emperor was being unfair. While the rebellion was crushed, it showed that the Emperor was now facing serious dissent from his Hindu subjects; from both nobles and commoners. \n\nThis new hard line policy against Hindus would be felt even more during the Deccan wars, when Hindu nobles were often accused of secretly aiding the Marathas and the other Hindu kingdoms fighting against the Mughals. Also there was the \"Jat Revolts\" of the late 1600's, while not completely Hindu in nature(since the Jats also counted a number of Sikhs and even some Muslims), the Jats did have a huge amount of Hindu recruits and they had the support of the Hindu people; who would covertly supply and shelter the Jat rebels. \n\nAfter Aurangzeb the Mughal state sorta of collapsed, and while the Mughal Emperor still ruled in theory, he had very little power. So Hindu dissent would no longer have been directed against the Mughal Emperor, but the various independent states that ruled in the Mughal Emperor's name.\n\nMy main sources for this were:\n\n\"The New Cambridge History of India: The Mughals\" by John F. Richards\n\n\"The Forgotten Mughals: A History of the Later Emperors of the House of Barbur\" by G.S. Cheema\n\n"
]
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"http://en.wikipedia.org/wiki/Persecution_of_Hindus#Persecution_by_Muslim_Rulers"
] | [
[]
] | |
2zh26q | why are my fingernails no longer translucent once they grow off the tip? | Im talking about the part you clip off, why is this foggy unlike the rest? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2zh26q/eli5_why_are_my_fingernails_no_longer_translucent/ | {
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"I'm sure you've heard about [tape over frosted glass](_URL_0_) trick right? Your nail is actually rough on the underside, especially with bits of dead skin still attached. The part of your nail that didn't grow out is firmly \"adhered\" to the nailbed so it appears translucent because the hydration provided by the nailbed smooths the rough underside like the tape smooths the rough side of frosted glass.\n\n"
]
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"https://www.youtube.com/watch?v=nRoL2q-tU-Q"
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2c5kv1 | why is correct torque important when tightening bolts? | I think I get why it's important in terms of under tightening bolts but why is over tightening an issue (other than tightening to the point of breaking the material being joined)? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2c5kv1/eli5_why_is_correct_torque_important_when/ | {
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"In Engineering design, bolts are selected based on the forces or stresses they will be subject to during use. If a bolt is over-torqued/over-tensioned, it will be subject to additional forces that it wasn't designed to withstand. This increase in forces could cause the bolt to snap or deform, or perhaps the threads will start to strip, causing the bolt to loosen.\n"
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ulqt6 | How many people actually set out to 'conquer the world'? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/ulqt6/how_many_people_actually_set_out_to_conquer_the/ | {
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"I doubt anyone with a realistic idea of the size of the world has ever seriously considered trying to conquer it. If you're willing to include people who have set out to conquer the *known* world, i.e. the world as far as they knew it existed, I'd say it's possible that Genghis Khan or one of the other Mongol leaders aspired to do so, although I can't find anything that specifically supports that. \n\nThere are also other ways to \"conquer\" the world besides military invasion and annexation to a state, and I'd suspect that ideologues from every part of the political spectrum have sought to \"conquer\" the world for their ideology via subversion, revolution, propaganda, and/or terrorism at various points in history. I'm sure many fascists, communists, Islamists, and for that matter democrats and capitalists, have envisioned and struggled for a world dominated by their system of thought. Of course, this is only slightly less crazy than wanting to conquer the whole world militarily.\n\n**tl;dr**: In the traditional sense, almost nobody. Have you seen how big the world is?!",
"Lenin and Alexander the Great, I believe, are the only people who made conquering the entire world their explicit goal. Interestingly enough, both got way farther than they had any right to expect. "
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[],
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8my2f1 | why are there worries about micro-organisms from earth affecting potential micro-organisms from other celestial bodies and vice versa, when they haven't adapted to do so? | I hear about it all the time. Sure, on Earth it makes sense for an isolated group of humans to be affected by a micro-organism that they haven't adapted to, but why is this a worry when no Earth life is on say, mars for example? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8my2f1/eli5_why_are_there_worries_about_microorganisms/ | {
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"We know nothing. There can be no microorganisms at all, they can be similar to our or completely different. We have no clue what to expect. That's why it is safer to assume the worst option and take all precautions. ",
"Lets say your eating Cheetos. Your hands and face get covered with Cheetos dust. \n\nWhile covered in Cheetos dust you get sent to mars to see if its surface contains Cheetos dust. Well if your covered in it, your tests will show there's Cheetos dust. \n\nThe point is really to protect the reliability of scientific experiments. Nobody is worried we'll create space aids or something like that.",
"As I understand it, if we find microscopic life on say Mars, we want to be as certain as possible that it is is native to Mars. If every probe we send is covered in earth's bacteria, it would be so much harder to know that what we found is extra terrestrial. ",
"So at this point, the main concern is just not contaminating experiments present or future. We don't want to accidentally detect our own life when exploring Mars, or in the future when exploring some of the outer icy moons. \n\nLonger term, the issue isn't so much disease as invasive species. It's possible that, eg, Earth microbes could be better adapted to certain areas on Mars or Europa or wherever and push out the native species, the same way that animals from one continent can push out native species on a different continent. Earth is a biodiverse planet with a long history of many different species, so it's not impossible that life here would have biological tricks that life on another planet, limited to small populations surviving in barely habitable areas, wouldn't have evolved. It's not for sure...it's also possible that the local life could have the advantage, but we would rather avoid taking the chance, especially when taking precautions doesn't cost us much. Eventually we'll probably send people and no doubt a bunch of bacteria will go along for the ride, but there's no sense spreading them around before then.\n\nLonger term, like in a science-fiction future where humans go between various earthlike planets, there are still ways microbes could mess you up even without being actual pathogens. For example, life from some highly acidic planet could just find stomach acid a pretty good habitat and cause digestive problems that way. Or life could happen to excrete something toxic like cyanide as a metabolic byproduct. "
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8njbsk | What role did protectionism play in causing the two World Wars? | There's been renewed focus on protectionism and trade wars due to recent events. I certainly buy that trade wars played a large role in the two world wars, but how big was that role? Trade wars certainly couldn't have been the sole cause of the wars.
I also have read a lot about protectionism playing a large role in WW2, but what about WW1? Was it any larger or smaller? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/8njbsk/what_role_did_protectionism_play_in_causing_the/ | {
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"[Here](_URL_0_) is an answer by u/true_new_troll to a similar question. Hopefully this helps!"
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"https://www.reddit.com/r/AskHistorians/comments/5piddn/were_protectionism_and_isolationism_of_usa/dcugkjz/"
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99cgkd | why do car manufacturers keep making similar styles instead of rebooting a more vintage style that people would spend crazy amounts on, or even making a new car thats similar to those vintage styles? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/99cgkd/eli5_why_do_car_manufacturers_keep_making_similar/ | {
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"Old designs are not very aerodynamic, as a result will use more fuel than modern design if everything else is equal.\n\n > a more vintage style that people would spend crazy amounts on\n\nThat would probably equate to a luxury car which by default wouldn't be produced in massive quantity. People also wouldn't pay as much as you think they would for newly produced model that looks like a vintage model. Vintage cars worth more because they're old and rare.\n\n > a new car that's similar to those vintage styles\n\nPorsche has been doing this forever. They improve aerodynamics while keeping design elements of old models.",
"People like exclusive things. Be that cars, watches, clothes, whatever. A real vintage car is rare, which means the owner has something that most people don't have. This makes that person feel better or more exclusive than his or her peers. Rebooting old vintage styles is just a copy, copies aren't exclusive because everyone can get them.",
"A lot of vintage styles come from a time where safety standards varied from more lenient to outright nonexistent. You do see companies lean on their heritage, but they have to take into account rider protection, crumple zones, the angles of the front of the car, and many other facets. It's why in a lot of those reinventions, you can see the inspiration, but they look a bit more rounded off and generally... beefier I guess.\n\nThe New Mini is a giant compared to the classic. The VW Beetle is a whole lot curvier. The sleek Mustang put on a lot of muscle in it's reinvention. All to meet the obligations of safety standards. Personally in this case, I think the substance is preferable to the style.",
"There is 2 reasons I can think of, one finicial and one technical. \n\nFinically, the amount of people that would be interested in a retro style car is probably just not enough to warrant full production. Customs and small quantity shops are already established and can produce many classic cars vs 1 production model. A major car manufacturer just wouldn't have enough motivation to produce that kind of car. \n\nTechnically, the design of cars changed drastically due to the driving forces of safety and fuel efficiency. Old cars often have poor aerodynamics making them less fuel effecient. The frame/structure of retro cars wouldn't be able to meet today's standards for crash safety. (There is a video somewhere of a crash test between a Chevy 55 bel air and a new Chevy car. You can see the crumple zones were not a thing back then)\n\nTldr; not enough people to validate a full production and its design would be too crap vs today's standards to even be legal. ",
"The plymouth PT ceuiser was a disaster, maintenance wise. The redesigned ford thunderbird was a bar of soap, causally neutered. The bubble top chevy s10 was also too effeminate. The chrysler HHR was just plain ugly.\nAs far as taking a risk, design wise, and selling well, i would nominate thepontiac aztek. It was novel, yet vintage in its blocky, cubist style. Everyone had one, 2002-2008"
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ocmul | If one swallows their own blood, will that slow the process of bleeding to death if in a situation of much blood loss? | askscience | http://www.reddit.com/r/askscience/comments/ocmul/if_one_swallows_their_own_blood_will_that_slow/ | {
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"nope.\n\nWhen you die from blood loss, its because you no longer have enough blood in your circulation to maintain enough oxygen to the tissues / or maintain enough pressure to keep the blood moving.\n\ndrinking blood will firstly make you very nauseous, and it will then be broken down into protein, then amino acids which will be absorbed. Thats great, but you dont need amino acids in your gut. you need some volume of blood in your circulation.\n\nalcohol is just one simple chemical.\n\nblood is a complex cocktail of cells and plasma. It cannot be absorbed without being broken all the way down into its constituent parts, which means you cant just absorb it as \"blood\". \n"
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qrvhy | Is PTSD (post traumatic stress disorder) more common in modern soldiers then say WWII or is it more dependent on the type of war fought? | From what Ive seen it seems that more soldiers today have life altering cases of PTSD then ever before in history, I admit this is most likely because of modern medical practice now recognizes it. However I feel as if wars never effected people mentally as they do in this modern age. I believe this has a large part to do with the type of wars fought, but could it also be a change in the humans ability to handle such situations and stay sane due to the world around them telling them everything they had just done and seen is wrong? | askscience | http://www.reddit.com/r/askscience/comments/qrvhy/is_ptsd_post_traumatic_stress_disorder_more/ | {
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"The historian Gwynne Dyer has some interesting thoughts on this question, which he explains in an interview here: _URL_0_\n\nHis discussion of PTSD starts a little after the 5:00 mark. Basically, his idea is that until shortly after WWII, most soldiers who had a chance to shoot at an enemy either didn't shoot, or missed on purpose (he explains quite a bit of evidence for this). When modern armies began stricter training regimes to ensure that soldiers would actually try to kill other soldiers, the results were 1) much more efficient armies, and 2) soldiers who felt that they had been \"tricked\" into shooting someone when this is generally very contrary to human nature - thus higher rates of PTSD. \n\n[Edit for clarification.]\n\nThe concept is an interesting one, and laid out very well by Dyer, I think. ",
"Finally, a topic that I have some experience in. PTSD has been discussed since at least the American Civil War and it seems has had a different name in each combat operation. There have been suggestions that PTSD has occurred all the way back to the Ancient Greeks, so it is not a new phenomenon. \n\nCurrently, you hear so much about it because we have the ability to spread information around the world in minutes. We also have a lot of contact with Soldiers. So the Soldier comes home and says he is having trouble sleeping and has been depressed, and because we hear so much about PTSD, the assumption is made he has it. \n\nFor the most part, it works. The Soldier gets a diagnosis so insurance will pay for it, the Soldier gets medication for the symptoms and everyone is happy. \n\nWe are doing a good job of treating PTSD. Medication and counseling are good treatment. Better than we did during WWII and the Korean conflict where it was denied and those afflicted were called cowards or traitors. Better than we did during the Civil War where we treated it with morpheme. 'Course we treated everything with morpheme then. \n\nLong story short, I think it is over reported, but I think that for the most part we are helping those who are affected by PTSD.",
"Though there have been historical documentation of PTSD in earlier wars (or at least people experiencing the symptoms of it), it wasn't until the 1980s that it was officially recognized as a diagnosis. It's hard to say if more people are being diagnosed now than they would have been in the past, let alone if the numbers suffering from PTSD are the same. \n\nThough war has changed in many ways, I personally don't think there is a massive difference in the psychological impact, war has been and still is traumatic, stressful and a particularly high risk factor for the development of PTSD.",
"there are no parades anymore (there is less public support, and it's harder to be proud of dirty deeds.)\nnazis were a clear, evil enemy and the cause was just.\n\nrifle marksmanship training is a form of brainwashing\n\nmovies show more gore, and we have been led to believe killing is glamorous--but actually, it just smells like a butcher shop.\n\nI made it through 3 rotations (deployments) in the last decade, and made it with my sanity intact, and my awareness... but. I strongly resent actors for playing so tough in movies. it's a lie",
"Consider too, that in earlier periods - let's say the Dark Ages - violence and death were much more common occurrences in daily life than they are today. I think modern people are psychologically less prepared to deal with these things.",
"* Nostalgia\n In 1770, \"severe homesickness\" (considered as a disease), Mod.L. (cf. Fr. nostalgie, 1802), coined 1668 by Johannes Hofer as a rendering of Ger. heimweh, from Gk. nostos \"homecoming\" + algos \"pain, grief, distress\" (see -algia). Transferred sense (the main modern one) of \"wistful\n\n[Copied from](_URL_0_)"
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5a8mu3 | why are fish only able to grow to a specific size, depending on the size of their tank? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5a8mu3/eli5_why_are_fish_only_able_to_grow_to_a_specific/ | {
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"It's a myth. Fish don't grow to the size of their tank. Their growth may be somewhat stunted by things like poor water quality due to the undersized tank, but they don't magically adjust their growth to fit the size of the container, and in any case, it's a serious health issue and not something that should be considered a steady state of affairs. If fish really did grow to the size of their tank, it would be possible for pet shops to sell miniature versions of fish far too large for the average home aquarium just by keeping them in a smaller tank. \n\nFish aren't bonsai trees. "
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3ppxgi | What was the first big corporation? | And did any corporations exist prior to the Industrial Revolution?
Thanks. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3ppxgi/what_was_the_first_big_corporation/ | {
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"Mate, I'm going to ask you to rephrase and resubmit this question. \"Big\" is such a relative term that you've asked a question that's going to be impossible to answer in a quality way, and you're going to get a bunch of short, poorly cited answers.",
"The short answer is the Dutch East India Company, chartered in 1602. It was enormous because of its monopoly of the spice trade and, per [Ricklefs (1993, 2nd ed)](_URL_0_), paid an annual dividend of around 18% for nearly 200 years."
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6uc2os | What affect does the quantity of injuries have on healing time? For example, would a paper cut take longer to heal if I had a broken Jaw at the same time? | Edit: First gold, thank you kind stranger. | askscience | https://www.reddit.com/r/askscience/comments/6uc2os/what_affect_does_the_quantity_of_injuries_have_on/ | {
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"There is an asksience threat from 2015 about (almost exactly) the same topic, maybe you'll find a satisfying answer there:\n\n_URL_0_ \n\nFor the lazy: these are the two top comments:\n\n* #1\n\n > \nDepends on how close they are too.\nWounds close mechanically as well as having regrowth. If you take a little biopsy from your skin, first off you have a scab, and you also have stem cells in reservoirs of stem cells around the wound that start to proliferate and these daughter cells migrate towards the centre of the wound where they meet, stop migrating and start to thicken up. Here is a picture where the green is skin (Keratin5) and red are stem cells, and the wound is to the right, so the skin you can see already starting to point to the wound centre. This wound is 4 days old.\nHere is a wound that is totally healed. The scab is the big weird thing on top.\nHowever, at the same time fibroblasts orientate towards the wound centre and start to muscularly contract the wound closed. A 1.5mm wound is basically invisible once the wound contraction is finished, a 3mm wound is less than half that size after a few days.\nAnd so several small wounds in a close location would not optimally contract and might heal slower.\nadditionally\nWounds need blood flow, and that can be effected with multiple wounds. If you have wounds that are local, and interfere with blood flow, they can become chronic wounds. Wounds that affect skin in a complete circle around the arm or leg can be like that.\n\n* #2 \n\n > not necessarily. If one had three paper cuts of small size on different parts of their body they'd all heal at the same rate.\nWhen learning about tissue healing, we are generally taught that there are three phases: Inflammatory response, Proliferation, Maturation/remodeling. In the inflammatory response phase, your immune system activates to fight off infection, when the wound is sufficiently \"sterilized\" the Proliferation phase begins. In this, the granulocytes start collecting near the wound area and new tissue is laid down in a messy \"spaghetti-like\" structure. In the maturation remodeling phase, the tissue is stretched and aligned along the lines of pull of the tissue and the tissue normalizes. That's a brief overview. The type of damage also plays a role. Incisions (straight edged cuts in skin) heal faster than lacerations (jagged edged cuts in skin, like tears). also the deeper the cut is, the longer it takes to heal cause tissues heal from deep to superficial layers. thats it in a sort of nutshell. If you have more questions feel free to ask!\n\n[and further down]\n\n > Your body has metabolic limits, you have limits on the resources you can take in through diet. With multiple wounds those resources are split. How split and how much that slows you down depends on all the usual factors - general health and diet primarily.\n\n**this last part seems to answer your question**, albeit without providing any source.",
"Common to have multiple injuries, like in the surgical ICUs from traumas. Healing comes down to infection control, nutrition (usually the issue) and rehab.\n\nWith large body surface area burn patients, very hard to feed them enough, even with a feeding tube 24 hrs a day to meet calorie requirements to heal.\n\nEdit for additional info: Acute critical illness can lead to catabolism exceeding anabolism, even in adequately nourished people. Obesity, is equal or more risk for wasting.",
"To answer the question simply, yes, absolutely. \n\nDifferent types of illness have unique calorie requirements. \n\nA polytrauma patient is different than a septic patient is different than a burn patient with regards to protein, carbohydrate, electrolyte, and fluid requirements. \n\nA dietician who works in the ICU could probably answer this question a lot more thoroughly than I can. I usually just write the order for a nutrition consult and leave it up to them. \n\nSource, am a doc, although this is definitely not my area of expertise. ",
"A distal injury won't affect another injury until it begins needing more resources than the body has to distribute - take burns for example. \n\nIf you had a burn on your hand all sorts of plasma and proteins and immune related cells would be rushing to the site (some already there) causing both local inflammation and an immune response that ultimately results in a blister - the blister is full of immune cells that help to repair the damaged tissues by providing an ideal micro environment for healing. Now let's say there's a burn to a large portion of your body; depending on the degree and the inflammation response (3rd degree burns have a different response as many of the biological channels of cell repair are completely destroyed) while your body will send out all its required immune cells that it has it might simply not be enough - in this case bacterial infections can take hold in the blisters as they provide an ideal environment for certain infections to grow, this results in sepsis and eventually septic shock. Imagine that the bodies immune repair system is spread too thin to repair both burns - it doesn't have a very good system at establishing where it should send immune cells with regard to controlling sepsis beyond directing blood away from the extremities and towards critical organs as septic shock progresses. \n\nUltimately it depends on the nature of the two injuries but yes they could affect one another.",
"A fun bit of trivia:\n\nIn polytrauma injuries involving a traumatic brain injury and bone fracture, the fracture may actually heal at a faster rate than the same fracture alone. The mechanism is currently not well understood, but some researchers speculate it's related to enhanced macrophage mobilization.\n\nEDIT: Oh wow, awesome discussion!\n\n\nEDIT2: For some more formal reading, check out some of work being performed in small animal models: [here](_URL_2_), [here](_URL_4_), [and here](_URL_1_). Then, even more exciting, check out [this study](_URL_0_) that looked at human patients with combined TBI + fracture injuries. Finally, to try to sum it up as best as we can, check out these lit reviews: [here](_URL_5_) and [here](_URL_3_)",
"I'm just here to say I love this sub for its great, well supported answers",
"I'm a pain management physician. There's a low likelihood that two separate injuries would significantly affect each other unless they are major (2nd/3rd degree burns, broken bones, etc).\n\nTwo injuries in the same area, however, if the second occurs before the first one is fully healed, or sometimes even after its healed, can predispose to longer healing times and ultimately decreased function and possibly chronic pain. There's evidence that prolonged pain and inflammation can cause neurological changes in nerves that can lead to chronic pain. That's why using ice, nsaids (such as ibuprofen), and most importantly, physical therapy, after an injury is important. ",
"There's a lot of great answers on here, and I've also seen several people ask if overall stress appears to affect healing. The answer appears to be yes. There's a famous study where students were given small cuts essentially and were found to heal more slowly closer to exam times.\n\nSome reading on this subject: _URL_0_",
"When you have an injury, say, a paper cut, inflammatory cells (neutrophils and others than have already been mentioned here) “travel” to the site of injury to help the inflammatory response that will eventually lead to healing. \n\nWith our bone marrow producing cells, we don’t have a “static” number of neutrophils, but for a minute let’s suppose we do have a standard amount circulating in our blood. So, if you have one cut, it’s easier for those guys to take care of it rather than 3,4,5 and more cuts. \n\nIt alas depends on the type of injury and the magnitude of the initial inflammatory response. \n\nHope I helped :)",
"I broke my left hand two weeks ago when a car hit me while biking. The nails on my right hand hand have continued growing and needed to be cut, however the nails on my left hand have stopped growing. Is this because healing the left hand is using resources before it reaches the nails?"
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"http://globalprojects.ucsf.edu/project/murine-model-polytrauma-understanding-molecular-basis-... |
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