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30ln2d | if the director's cut is different from the theatrical cut, then whose cut is the theatrical cut? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/30ln2d/eli5_if_the_directors_cut_is_different_from_the/ | {
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"The producers' and studio's, essentially. The people putting up the money get final say. If their decisions differ wildly from the director's, the director may release a cut of his own later.\n\nThe director and producers both work alongside the editor and the editor may lean more to one side or the other. Sometimes the director, the producer, or both just trust the editor to make their own decisions.",
"In filmmaking, there is a concept called final cut. Whoever has final cut can contractually say what the theatrical release is. \n\nThe directors cut is the version the direct thinks best exemplifies their vision of the story. At some point, powerful directors (think Scorsese or Spielberg) were given final cut in their contracts. That means the directors cut is the theatrical cut. \n\nOther times, directors had their version of the film changed against their will. \n\nThe directors cut you see released on dvd night just be a marketing gimmick. It can be an excuse to sell another version with more footage. I think there is a version of the exorcist that that is labeled as the directors cut but the director claims the original theatrical cut is his preferred cut. "
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yz8ia | Did Japanese houses not get wet with only paper walls? How long have they been made like this? | Edit: So no answers huh? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/yz8ia/did_japanese_houses_not_get_wet_with_only_paper/ | {
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"I'm in no way a knowledgeable source, but I believe they had fairly large awnings and the rice paper most likely had a waxy outside coating, but this is just conjecture. Sorry I couldn't be of more help!",
"You mean shoji? \nI've lived in Japan, usually there are windows in front of it, if not, then straw.",
"In Korea it was a custom in some parts for the old women of the village to poke holes in the paper walls. During the wedding night. To \"check up\" on the couple."
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1yrbqs | why hasn't the price of black market drugs changed 15 years when everything else has gone up? | A gram of Marijuana has been $10 or $200-240 an ounce since I was old enough to know what it was and how much it costs which has been about 17 years, its likely it has been those prices for even longer.
The cost of a chocolate bar has gone up 23% since 2000 alone, why has inflation / increased wages not effected the black market? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1yrbqs/eli5_why_hasnt_the_price_of_black_market_drugs/ | {
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"The price of marijuana may not have changed, but other drugs do have changes in price. \n\nJust like any other good, they too follow principles of economics( supply-demand, inflation, etc )",
"Jesus you get your stuff for cheap as"
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99ccp4 | while sand is abrasive and opaque, why glass made from that is such smooth and transparent? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/99ccp4/eli5_while_sand_is_abrasive_and_opaque_why_glass/ | {
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"Sand is mostly silicone dioxide and when melted it is changed at a molecular level. When it cools it forms a smooth clear substance.",
"Sand is basically quartz crystals, sharp and very very hard, while glass is an amorphous solid, which doesn’t mean it’s a liquid like they might tell you, but means the molecules are scattered around randomly not forming a crystal, it’s not a liquid, but it’s basically a still image of liquid quartz that is solid",
"Sand is a collection of small grains that are unaligned. Glass is a single grain, and its manufacture is precisely controlled to give that transparency - opaque glass is very much a thing, though not a desirable one usually. ",
"Imagine taking a sheet of glass and smashing it into dust. While it would be much sharper than sand as it hadn't been weather's for thousands of years, it would have the same qualities of being abrasive and opaque. \n\nEdit:spelling"
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42ux0y | why do the same injuries hurt so much when you're young and when you're old you might not even notice it? | I remember my dad getting splinters out of my feet and it felt like it was the end of the world. Now, I cut myself open and superglue it together and get back to work. Why? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/42ux0y/eli5_why_do_the_same_injuries_hurt_so_much_when/ | {
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"Pain is relative.\n\nWhen you were younger, your most painful moment could have been when you fell down and scraped your hands on the pavement. And then one day, you are getting your sprinters ripped out of your flesh AND OMG THIS HURTS MORE THAN ANYTHING YOU HAVE EVER FELT.\n\nAs you get older, you end up with more experience with pain. It doesn't have to be physical like breaking a bone. Having your heart broken, the stress of losing your job, the sadness of losing someone you loved are all types of pain that we experience. When we have lived through all that, a single cut seems so minor.\n\nBut remember that people all have different experiences. If the same painful event happens to two people, they could feel vastly different amounts of suffering."
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q4nia | If you mechanically separate a solid into one-molecule pieces, would it behave as a liquid? Why or why not? | Say you take a giant salt crystal and grind it so finely that no piece is larger than a single NaCl molecule. How would it behave? Would it flow like a liquid? Or would it clump together like a powder? If the latter, what's keeping it from acting like a liquid if all the molecules are separate and not bound into a solid structure?
**edit**: thanks for the responses. | askscience | http://www.reddit.com/r/askscience/comments/q4nia/if_you_mechanically_separate_a_solid_into/ | {
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"If the molecules aren't in contact, you have temporarily created a gas.* Upon contacting each other, the molecules will bond and a solid will accumulate. At no point, assuming you're at standard temperature and pressure, will you have the conditions that produce a liquid.\n\n*This broadly describes a process called \"sputtering,\" which is often used to coat surfaces. Here, though, the molecules are knocked out of place by ion bombardment instead of being finely ground. Fine grinding to a uniform single-molecule consistency is impractical. "
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25zqj9 | Was the Christianity practiced by the western Roman Empire and Western Europe prior to the great schism more similar to modern day Catholicism or Eastern Orthodoxy? | Also, if so, why did this difference in religious practices between the Eastern and Western Romans emerge? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/25zqj9/was_the_christianity_practiced_by_the_western/ | {
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"The answer is going to be a little infuriating. Simply the Western (roman rite) Church developed into the Roman Catholic and then Protestant sects. The Eastern Church developed into the Eastern Orthodox Church. The churches were functionally unique and autonomous well before the East-West Schism. The primary reason for the split was both cultural and political although there were some theological differences between the churches well before the official split in 1054. Possibly the biggest theological difference comes form this lingual and cultural difference. (I cited Pelikan, Jaroslav in my paper here but I can't seem to find a good online version of his work The Spirit of Eastern Christendom (600-1700)) The first big theological difference is know as fillique. Basicly the Roman Rite (I dont mean this in a conspiratorial way) inserted the phrase filique into the Latin recital of the Nicene Creed. This phrase means [\"and from the son.\"](_URL_0_) This is not in the Original Greek. The Catholic church has since removed this phrase from its greek recital of the the Creed although they [stick behind their reasoning behind the phrase](_URL_1_). (link 255 for a quick glimpse) This has been an area of major theological contention for quite some time with the earliest documented case of the insertion popping up in the latin coming from the the 6th century. Although this is phrased in my source (linked above) in such a way as to imply that this was because earlier records are gone rather than the 6th century was where the change originated from. Another area of difference is the idea of theoria versus metaphysics. Unfortunately my sources for this area are not up to snuff so I will save this for another poster to expand on.",
"I wasn’t going to comment, I really was going to let this one go. But then I read the answers posted, and I couldn’t stop.\n\nSo, just to set ourselves up, we are talking about 1000 years of history here, from the arrival of Christianity in Rome in the mid to late 1st century (I would say at least by the 50s), and the Great Schism in 1054. The thing we must first realise is that Western Christianity (and by ‘West’ I mean basically draw a north-south line on your map roughly where Tirana, Albania is) diverged from its Eastern (and I will primarily talk about Eastern Orthodoxy, not about the non-Chalcedonian Church of the East and Oriental Orthodox churches) counterpart long before that Great Schism occurred, in fact, was probably moving in different directions almost from the start.\n\nThe first factor is simply language. The western half of the Empire was dominated by Latin, and the East by Koine (and later Byzantine) Greek. Although the church in Rome, and possibly in Gaul as well, originally functioned in Greek, they later switched to Latin (the liturgy switched around the 4th century; first Latin theological writings appear around ca 180; the most important western theologians apart from Irenaeus begin to write in Latin: Tertullian, Novatian, Cyprian, and so a Latin theological tradition develops). \n\nNow, while Rome maintains links to the East, most of the churches west of Rome, and to some extent North Africa, maintain their primary connections with Rome. So ‘western’ churches are operating almost entirely in a Latin sphere. You see one evidence of this in the fact that all the so-called Ecumenical councils (Nicaea, Constantinople, Ephesus, Chalcedon, etc..) occur in the East, and have very, very poor attendance by Western, Latin bishops. They deal with theological disputes that occur primarily in Greek.\n\nThis linguistic divide is tied up with cultural divisions that develop over time, and also with liturgical development that runs along different trajectories. \n\nSecondly, you have to deal with political matters. Once the empire was not merely nominally but effectively divided in two, they begin to operate relatively autonomously. This doesn’t go so well in the West, as we should mostly know by now, and the successive migrations of Goths, Vandals, Lombards, etc., and especially the Franks, causes significant change in the political, social, and cultural landscape of Western Europe. Especially when Illyricum (the modern Balkans) come to be dominated by the Huns, inter aliis, it severs the land-connection between East and West, further dividing their relations.\n\nConnected to this, in the early to mid Middle ages, the rise of the Franks as the only real major consolidated power in Europe, and the only kingdom that is following Catholic Christianity (as opposed to the non-Nicene versions prevalent among Goths and Vandals), also has an influence on the general cultural and political milieu of Western Catholicism.\n\nIn all this time *the East is not static*. It is sometimes apologetically cute to say the Orthodox church has an unbroken tradition back to the earliest church (kind of true), but it changed and developed. in the East you have long and protracted theological debates over the natures of Christ (monophysitism on the one hand, dyohypostastism on the other), the development of a distinct Monastic culture, several periods of Byzantine intellectual flourishing, and of course the development of icon theology and practice in the midst of iconoclastic debates, which touch upon Western Catholicism but not in the same way.\n\nThirdly, of course, the Western Church has the development of the Papacy as both institution and theological dogma. It orients the Western church in a more ‘monarchic’ way than the Eastern church, which continues to practice a more collegial hierarchy. One example of this would be that when dealing with mission efforts among Slavs and Bulgars, the Western Catholics insisted Latin be the language of worship, whereas the Orthodox promoted the use of Slavic, translated both Scriptures and Liturgy, and established the Bulgarian church as a separate and independent hierarchical institution. \nIt is simply and patently untrue to say, as another poster has, that E.Orthodoxy remains relatively unchanged since the 11th century. While there has probably been slightly less liturgical innovation in the Greek Orthodox churches than the Roman (especially with Vatican II), there has been plenty of theological development. I would not actually want to venture a proper answer to OP’s question, of whether the pre-Schism Western church was more similar to contemporary Roman Catholicism or contemporary Eastern Orthodoxy. It’s a no-win question that flattens the historical field in what I think is an inappropriate way\n"
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1sqena | what are the pros and cons of a forward swept wing aircraft? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1sqena/eli5_what_are_the_pros_and_cons_of_a_forward/ | {
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"It's like having rear wheel steering- very maneuverable but not stable. \n\nEven more five year old- push your red wagon by the steering handle and see what happens. ",
"A major con of it is very high drag and very high forces at the shoulder joints. Think of it like when you try to glide through water. You will find less force pushing back if you let your arms sweep back than if you have them sweep forward. It will also take more effort to keep them forward.\n\nYou can play around with different designs here to see for yourself:\n_URL_0_",
"Instability is sought after in fighter designs, as an unstable plane can maneuver in ways difficult for a stable design, giving an edge over the enemy. Forward sweep was investigated as a possible advantage, primarily with the X-29, and it was found wanting for the reasons other posters mention. Forward sweep appeared about 30 years before the X-29.. On the fictional Thunderbird 2!"
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47gydn | us congress and stocks, how are those things not a conflict of interest? | It just seems to me that the people in power of making laws in this nation shouldn't be able to both create laws and own stocks in the companies they are making laws for. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/47gydn/eli5_us_congress_and_stocks_how_are_those_things/ | {
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"It is a complete and total conflict of interest. They briefly banned insider trading in the senate (?) but it was quietly removed. It's disgusting and certainly part of the reason people on both ends of the political spectrum are supporting \"outside\" candidates in the primaries."
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1r3gmd | what causes my green eyes to vary in color throughout the day? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1r3gmd/eli5_what_causes_my_green_eyes_to_vary_in_color/ | {
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"Your eye color doesn't really change, it's how we perceive it that changes. Now here are some factors that changes the color of your eye: the angle, type of light, and whether your eyes are dilated or not. \n\nWhen you look at an object at different angles it changes color, best example is like the color of a lake vs where the sun is in the sky.\n\nLight from your lamp and let say, light from your classroom (fluorescent) can change the way your eye color is perceived.\n\nAnd lastly, dilated eyes I believe provides a lighter color vs constricted eyes though the difference can be hard to see.\n\n",
"It is probably due to color constancy... our perception of color changes based on the background. Your eye color doesn't vary, but our perception of the color may change.\n_URL_0_",
"I've looked this up before. According to [Wikipedia](_URL_0_), there isn't exactly any such thing as green eyes - or rather, a green iris. Rather, your iris is a sort of hazel color, and a trick of the light called Rayleigh scattering imparts the blue color. Combined, they make your eyes look green. When the external light changes, the Rayleigh scattering changes, and your eyes look more blue, or more hazel like your true iris color. \n\nFun fact, my green eyes are unique in my family. Now, the mailman's eyes... ;)"
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3e3qa7 | how is it that in 2015, we can't use science to accurately recreate stradivarius violins? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3e3qa7/eli5_how_is_it_that_in_2015_we_cant_use_science/ | {
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"We'd need to know what we were recreating. Where the wood came from and what the weather was like every single year that those trees grew, what chemicals were applied in what quantities and how, where was it stored and for how long?\n\nWe don't know a lot of those things.",
"The assumption here is that a Stradivarius really is objectively better and that we can't reproduce it.\n\nIn multiple studies, the world's best violinists are unable to tell a Stradivarius apart from a modern violin:\n\n_URL_0_\n"
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3slmgb | how can judges legally require citizens to do "community service"? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3slmgb/eli5_how_can_judges_legally_require_citizens_to/ | {
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"Because the relevant lawmakers decided it would be a good idea, drafted laws to that effect, and passed them. That's what it takes to make something \"legal\": a law. ",
"The same way they can legally require you to pay a fine or go to jail. Most of the time, community service is done in place of the other options.",
"Because judges are arbitrators whose legal job it is to prescribe a punishment, and unless the law mandates a specific punishment (such as mandatory minimum prison sentence) or the punishment is illegal (you can't sentence someone to rape for example) then it's all good",
"It depends on the country, but in the United States, judges can sentence anyone to any punishment as long as it isn't \"Cruel\" or \"Unusual\". The ban on \"Cruel or unusual\" punishment is part of the 8th amendment, and defined by the Supreme Court though the appellate process.\n\nSince most people would gladly perform community service rather than go to jail, or pay a hefty fine, community service sentences are rarely, if ever, appealed. This does not mean the underlying verdict is not appealed from time to time, but I have never heard of anyone appealing 500 hours of trash pickup because it was \"cruel or unusual\".",
"13th amendment bro: Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction."
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865hxp | Is there such thing as a double Gamma function similar to the Double Factorial? | After watching [blackpenredpen's latest video](_URL_0_) I was motivated to try to derive an analytic function for double gamma that would extend the double factorial to non-integer numbers.
I came up with the following: (i don't see this in the [wikipedia article](_URL_1_)
Define the Double Gamma Function Γ² (x)=( 2\^((x-1)/2) \*Γ((x+1)/2)\*sin²(π/2\* x) + 2\^(1-x/2)\*Γ(x)/Γ(x/2)\*cos²(π/2* x) ) / √( 1+k*sin²(πx) ) where k~0.0127996745295915
This has all the properties we want of the double factorial including:
- Γ²(n+1)=n‼; (Double Gamma equals Double Factorial for integer values of n)
- Γ²(x+1)*Γ²(x)=Γ(x+1); (same relationship as double factorial, n‼*(n-1)!!=n!)
- expand double factorial to all real numbers except on the poles that are located at the negative even integers
- Γ²(0+1)=1; so 0!! = 1
Here are values of x, Γ²(x+1) and Γ²(x+1)*Γ²(x)=Γ(x+1) for 0 to 7 incrementing by 0.5
x | Γ²(x+1) | Γ²(x+1)*Γ²(x)=Γ(x+1)
---------|----------|----------
0 | 1 | 1
0.5 | 0.9628 | 0.8862
1 | 1 | 1
1.5 | 1.3806 | 1.3293
2 | 2 | 2
2.5 | 2.4070 | 3.3233
3 | 3 | 6
3.5 | 4.8323 | 11.631
4 | 8 | 24
4.5 | 10.831 | 52.342
5 | 15 | 120 |
5.5 | 26.577 | 287.88
6 | 48 | 720
6.5 | 70.406 | 1871.2
7 | 105 | 5040 | askscience | https://www.reddit.com/r/askscience/comments/865hxp/is_there_such_thing_as_a_double_gamma_function/ | {
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"You are seeking a function *F* that has the following properties for non-negative integers *z*:\n\n1. F(z + 1) = z!!\n2. F(z + 1)F(z) = Γ(z + 1)\n\nWe would also like *F* to be defined on some set larger than just the non-negative integers, say, some open set *U* of **C** containing the non-negative integers. Ideally, *F* would be analytic on *U*.\n\nFirst of all, the two conditions are redundant. So it's a choice of whether to keep condition (1) or (2). If we keep only condition (1), we are really just looking for a smooth curve that interpolates some set of isolated points. So existence is not an issue, but uniqueness certainly is. Condition (1) is a very non-restrictive condition, and we would not get very far. So, just as with the gamma function, we consider the recurrence relation to be fundamental. \n\nHence a better set of conditions is the following:\n\n1. F(1) = 1\n2. F(z + 1)F(z) = Γ(z + 1) for all *z* in *U*\n\nNow existence is not obvious, and uniqueness is still not achieved. For instance, let *f* be any analytic function such that f(1) = 1 and f(z+1)f(z) = 1 if *z* is a non-negative integer. Then if *F* satisfies the above conditions, so does *G*(z) = f(z)F(z). (One such function *f* is f(z) = exp(sin(πz)).) The same problem arises for the gamma function. So to get uniqueness, we have to impose at least one other condition. For the gamma function, the appropriate third condition turns out to be logarithmic convexity. Then the gamma function is uniquely determined for positive, real numbers, and from there analytic continuation takes care of the rest. I don't know whether there is a similar condition we can add to our list to determine a unique *F*.\n\n---\n\nNow you have proposed the following function even before considering whether we have defined *F* uniquely (we haven't).\n\n[click for equation](_URL_0_)\n\nYour formula does satisfy both conditions if *z* is a non-negative integer, and it does this for *any* value of *k*. You've simply chosen your value of *k* so that condition (2) also holds for half-integers. In fact, the exact value of *k* in your formula is\n\n[click for equation](_URL_3_)\n\nYour formula does not satisfy condition (2) in general. Indeed, if you simply calculate the expression F(z + 1)F(z)/Γ(z + 1) you will find that the expression depends on both *z* and *k*. So there is no way to choose *k* to make your formula satisfy condition (2) for, say, all positive numbers.\n\nIf you want some hints on how to proceed, first off, just get rid of *k*. That is, set k = 0. There's also no (initial) reason for the squaring of the trigonometric functions. So let's just deal with the following function then.\n\n[click for equation](_URL_2_)\n\nI will leave it to you to verify that this formula for *F* then automatically satisfies conditions (1) and (2) for all non-negative integers *z*. I will also leave it to you to calculate the ratio R(z) = F(z+1)F(z)/Γ(z + 1) and show that R(z) is periodic with period 1, i.e., that R(z+1) = R(z). Hence if we let S(z) = R(z)^(1/2), then the function G(z) = F(z)/S(z) satisfies condition (2) for all positive, real numbers (in fact, for all complex numbers wherever the expression makes sense in the first place). Furthermore, the function G(z) has no poles on the positive real axis and G(z) > 0 for all positive z. [Here is the formula for G in all its glory.](_URL_1_) The graph of *G* almost looks like the gamma function, but it's sort of \"lumpy\".\n\nOf course, this function *G* is not unique, and you can find for yourself that it bears a striking resemblance to the formula you have found. But unless we give some more conditions for our double factorial extension, the best we can really say is that there *exists* such an extension. If you want to stick with your formula, you can do the same sort of trick by computing the ratio R(z) and then, if the function happens to be periodic with period 1, modify your formula by dividing by the square root of R(z). Of course, you can then choose whatever you want for the value of *k*. But since the value of *k* in your formula is irrelevant anyway, there's no reason to include it.\n\n\n\n\n"
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4rzctd | why does bushfire smog often appear red (i live in melbourne australia) and not just shades of gray? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4rzctd/eli5_why_does_bushfire_smog_often_appear_red_i/ | {
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"Our primary source of light is of course the sun. As we know, the visible spectrum can be simplified as red, orange, yellow, green, blue, indigo and violet. These are listed from [lowest to highest frequency \\(or largest to smallest wavelength\\).](_URL_0_) [\\[Source\\]](_URL_1_)\n\nThe red-coloured smoke we see likely has to do with sunlight being filtered by the thick layer of smoke in the sky before it reaches our eyes. The smoke absorbs a sizeable amount of higher frequency light being emitted by the sun, while reflecting lower frequency light.\n\nTo put it simply, because visible light from the ultraviolet end of the spectrum is being absorbed by the smoke and visible light from the infrared end of the spectrum is being allowed to pass through, the smoke appears red.\n\nEDIT: Added more specific information on frequency and wavelength."
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2927yd | What historical abuses of diplomatic immunity, if any, have occurred? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2927yd/what_historical_abuses_of_diplomatic_immunity_if/ | {
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"The Libyan Embassy incident in London comes to mind, where automatic weapons fire from inside the embassy killed a London policewoman. No one was ever prosecuted.\n_URL_0_\n\n_URL_1_\n\n",
"Sorry, we don't allow [throughout history questions](_URL_1_). These tend to produce threads which are collections of trivia, not the in-depth discussions about a particular topic we're looking for. If you have a specific question about a historical event or period or person, please feel free to re-compose your question and submit it again. Alternatively, you may PM /u/caffarelli to have your question considered for an upcoming [Tuesday Trivia](_URL_0_) thread."
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y9juh | What cool counter cultural movements were there before the 20th century? | whenever someone talks about a "counter-culture" it usually refers to the last century or so, did they exist before then in a big enough way to impact the world? What were they?
Btw I don't mean the "fuck yeah topple the government and behead the king" kind of movement | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/y9juh/what_cool_counter_cultural_movements_were_there/ | {
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"Well, from around 700-200BCE China was divided into warring states (the severity of the warring definitely increased over time), and there were many a wandering scholar.\n\nThey went from state to state looking for employment. They often subscribed to a school of thought, or had invented their own with a following. This is really cool in and of itself; the most famous of said scholars would probably be Confucius, but I actually came here to talk about a guy named [Mozi](_URL_0_) and the movement he started.\n\n[Mohism](_URL_1_) at its core (in my opinion) advocated universal love. This was greatly at odds with Confucianism which thought some people (such as parents) deserved better treatment than anyone else. \n\nThe Mohists were against war in general, as it was wasteful, but they recognized that defensive war was a necessary evil. Mozi himself was actually a great engineer, and his disciples became well-known for their sound defensive strategies especially in siege situations. They wore special, plain robes to distinguish themselves from other wandering scholars and also to show their value on utilitarianism (why wear a fancy robe if all you need is a plain cheap one?). This emphasis did however result in one belief that I strongly disagree with however: they didn't like music and art because they thought it was a waste of resources without alot of benefits.\n\nThe long period of disunity ended when a state that was based around a new philosophy (Legalism) managed to reunite China with a much more imperial style of feudalism (advocated state rather than noble control of land). The new group set a precedent of state orthodoxy, when they were overthrown Confucianism became the standard philosophy more or less until the end of the Qing dynasty in 1911/12. \n\nAlthough Mohism ceased as a school after the rise of the Qin, the basic ideas of Mohism were known by most Chinese scholars and likely had an impact on Chinese thought right through the present day.\n\nTL;DR Mohists were cool wandering scholars in classical China who sought employment wherever a king/lord was willing to hire them. They excelled in defensive (particularly siege) warfare. They advocated universal love and utilitarianism.",
"I don't know what you'd class as cool but leading up and around the French Revolution (the Romantic era) you had many counter-culture movements, especially in philosophy, art and literature. The poets Wordsworth, Coleridge and Blake believed in the dissolution of marriage, free love, no organised religion and other such ideals that made the hippies seem like johnny-come-latelys. De Quincey also did a lot of opium (that was readily available back then as medicine) and wrote several books on dreams and reveries that can easily be compared to some of the writings of the Beat movement. Additionally, the Shelleys (Mary and Percy) and Byron, also known as the second generation of Romantic writers, also were proponents of this philosophy. Mary Shelley's mother and father (Mary Wollstoncraft and William Godwin) were famous philosophers of that era, in addition to political philosophers like Thomas Paine. They advocated different philosophies like women's rights, free-love and anarchism. You might find this Kate Beaton comic helpful: _URL_0_ (It refers the author Goethe who wrote \"The Sorrows of Young Werther\" that you might want to Wiki. Plus I just love Kate Beaton. Make sure to check out Part II, too!)\n\nA word of advice: rarely will you find many counter-culture movements that were on a grand scale like that of the 1960s-now. That is because the enormity of the boom of population after the Second World War had never happened before. Never before in the course of human history had the young generation vastly outnumbered the old. This is something that we are still feeling the effects of today (especially in politics) and will do in the so-called \"Great Boomer Die-Off\" when countries like China and America (especially China) will shrink considerably in population because people are not having enough kids to replenish those who are dying. Chances are that this will prompt another counter-culture revolution when this happens as the population will balance out again.\n\nEdit: TL;DR: Romantic era hippies were pretty cool; 60s counter-culture happened because of Boomer generation and you will rarely find a counter-culture on that (demographic) scale in human history (to my knowledge).",
"At the start of the century (pre Word War I) there were some interesting social experiments that could be described as counter-cultures. See for instance the 'Wandervögel' movement (in some ways a precursor to the hitlerjugend) but also to environmental movements. See 'Fanny von Reventlow'; who hosted bacchanalia-like events; 'Wilhelm Diefenbach' who started a nudist vegetarian commune, the hippie avant-la-lettre 'Gusto Gräser' (hermann Hesse used to be part of his commune), the mystical 'Madame Blavatsky' (George Bernard Shaw based some of his ideas on her), she sort of started the theosophical movement, which Rudolf Steiner became a part of (and parted from, because of his radically independent ideas). These people and their movements were more or less cults, but they were profoundly counter-cultural. This all comes out of Phillipp Blom's 'The vertigo Years'",
"Julius Caesar and the hip young crowd he ran with apparently wore their togas \"loose\", whatever that means.",
"I know you asked about before the 20th century, but there's a little known group I find pretty awesome: The Stilyagi were a 1940s counterculture group in Russia that dressed how they imagined stylish americans did and listened to western music cut into x rays (rocking on the bones)\n\nThe government opinion of them can be summed up by the slogan \"today he dances jazz, tomorrow he sells his homeland\"",
"Ars Subtilior composers. Basically the avant-garde of 14th century France.\n\n_URL_0_"
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ip18t | "Tequila makes me so crazy." Any truth to different liquors and different effects? | Is there any evidence for different types of liquor having different effects, especially on the brain? Talk to most anyone who drinks, and they'll tell you - tequila, no, I'll be dancing on the table; gin makes me angry; bourbon gets me drunk so fast. Is there any research that supports this? | askscience | http://www.reddit.com/r/askscience/comments/ip18t/tequila_makes_me_so_crazy_any_truth_to_different/ | {
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"[Do different types of alcoholic beverages really induce different types of drunkenness?](_URL_0_), asked a few days ago :)",
"Could an experiment on something like this even be devised? ",
"Disclaimer: I don't remember where I learned this (It may have been undergrad o-chem, we spent a week on the chemistry of mind-altering substances)\n\nethanol exists in many states of hydration, properly written as (CH3CH2OH) * 6H20, 5H20 etc (note: this is a simplification, obviously chemists have drawn lines in the sand where no true lines exists). This denotes the number of water molecules bound in some way to the ethanol. This was originally razed in the context of liquor connoisseurs (i.e. can people distinguish different hydration states in vodka, scotch etc.)\n\nBecause each number requires a different geometry to surround the ethanol properly, it doesn't seem like too much of a stretch to imagine this effecting the activity of proteins, by either enhancing or reducing the ability of ethanol and its metabolites (quantities of which could also be altered by different hydration), to act as agonists to receptors in the brain. \n\nWhile the placebo can be quite strong, personal experience acts a strong anecdotal evidence in favor of this hypothesis ;-). I would love if anyone could supply me with some reliable sources about this.",
"Low quality cheap cachaça (*) can contain all sort of nasty stuff (**). Copper and other metal impurities from the distilling apparatus, phenols and other aromatic compounds, heavy alcohols, benzene, methanol,... all kinds of nasty stuff produced from the fermentation that failed to be adequately distilled. \n\nIt's anecdotal evidence , but people commonly joke here in brazil on how a person can get reaaally nuts when drinking one of those cheap cachaças. And given that methanol and other things I've mentioned do have psychoactive effects, I don't think it would be far fetched to say that it's probably because of this other substances. \n\nI don't think it would be so very different for other kind of fermented/distilled beverages of poor quality. \n\nBut again: this is for really bad stuff you wouldn't want to drink at all. Like cachaças and vodkas that would cost two dollars for a bottle. In beverages of attested quality, the levels of those substances are carefully controlled, so I don't know if there's something about them that could cause different effects. \n\n(*) Cachaça is a brazilian beverage, a distilled spirit made from sugar cane. People frequently call it a rum, but it's not a rum. It's not made from molasses but it's distilled directly from fermented sugar cane juice. \n\n(**) I only got a reference in portuguese for this.\n_URL_0_\n"
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34e5yv | What did Confucianism and Neo-Confucianism have to say about sex? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/34e5yv/what_did_confucianism_and_neoconfucianism_have_to/ | {
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"Sexuality wasn't a central concern of Confucianism, not as it is in Abrahamic religions. Propriety and temperance (as in, avoiding any physical excesses) are the main emphasis. \n\nSo, there's an old book called *The Ethics of Confucius* by MM Dawson that pulls teachings from a few different Confucian (or credited-to-Confucius) texts and organizes them by topic for Western readers. The section [down the page here](_URL_0_) on \"Sexual Propriety\" ties a lot of different passages together, most of which a little... non-specific. \n\n\"The scholar keeps himself free from all stain,\" from the *Book of Rites*. \n\nAnd: \"To find enjoyment in extravagant pleasures, to find enjoyment in idleness and sauntering, to find enjoyment in the pleasures of feasting—these are injurious,\" from *The Analects*. \n\nAnd even, from one of the commentaries on the *I Ching*: \"Heaven and earth are separate and apart, but the work which they do is the same. Male and female are separate and apart, but with a common will they seek the same objects.\"\n\nMen and women each have their own spheres of control, in other words, and shouldn't be mixing too much. \n\nDawson also quotes Mencius: \"When a son is born, what is desired for him is that he may have a wife; when a daughter is born, that she may have a husband. All men as parents have this feeling. If, without awaiting the instructions of their parents and the arrangements of the intermediary, they bore holes to steal a sight of each other, or climb over a wall to be with each other, their parents and all others will despise them.\"\n\nOne of Mencius' big ideas was balancing internal (mmmaybe \"spiritual\") and external (let's call this \"biological\" for now) needs to cultivate the *xin* or \"heart-mind\". Elsewhere in the book that bears his name ([*Mencius*](_URL_1_)(pdf), book 6A4), he has a dialogue with Gaozi (definitely another sage, probably another Confucian) that dips really briefly into biological imperatives: \n\n > Gaozi said, “Appetites for food and sex are part of our nature. \n\n > Humanity (*ren*) is internal rather than external; right (*yi*) is external rather than internal.”\n\n > Mencius said, “Why do you say humanity is internal and right external?”\n\n > Gaozi said, “If a man is my elder and I treat him as an elder, there is nothing of the elder about me. It is as if he were white and I treated him as white, I merely follow the external fact of his being white. This is why I treat it as external.”\n\nAnd it goes on from there. \n\nThe bit about sex being a necessary appetite is really not remarked on directly in the exchange... they wind up talking about roasted meat, in fact. The appetites seem more or less *morally* the same. \n\nPrior to that dialogue, (in Book 5A), Mencius refers to sex (or \"taking a wife\") as a \"fundamental human relationship,\" but places it in a kind of hierarchy of how we ought to love: \n \n > “When we are young, we yearn for our parents. When we are old enough to have sexual desires, we yearn for youthful beauty. When we are old enough to have a family, we yearn for wife and children. When we are ready to take office, we yearn for a lord, and without a lord’s approval dissatisfaction burns within us. But the greatest filiality yearns for parents to the end of life. In Shun, I see a man who yearned for his parents even at fifty.”\n\nSo you can maybe see that earlier quote about the young lovers as an expression of \"good\" versus \"bad\" ways of dealing with biological drives versus personal cultivation and social mores. \n\nWell after Mencius, the neo-Confucians were considerably more uptight, but I'll let someone with better chops get into what they were all about. \n\n\n"
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w5o9p | Yesterday there was a thread about how people in medieval times dealt with pain. As a follow up, how did pain management progress from the medieval period to the advent of evidence-based medicine? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/w5o9p/yesterday_there_was_a_thread_about_how_people_in/ | {
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428wcl | what is actually happening when matrices are being multiplied? | I often have trouble recalling the restrictions of matrix multiplication and how to perform the multiplication by hand. Without an understanding of what the math is representing, I find the operation more difficult than I should. Is there an intuitive way to understand this operation? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/428wcl/eli5_what_is_actually_happening_when_matrices_are/ | {
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"When you do the typical scalar product on two vectors, you are essentially adding the contributions of every entry on the vectors to get a specific number. Also, these scalar products are usually written as a (row vector) x (column vector).\n\nSo instead of the usual notation of v.w, instead use v^t w, where v^t is the transpose of the vector, and use the usual matrix multiplication to get the answer.\n\nNow, a matrix is like a list of vectors, written in either row vector form or column vector form, doesn't matter. So when you multiply two matrices, to get the first entry of the resultant matrix, you do a scalar product of the first row vector of the first matrix with the first column vector of the second matrix. You keep doing this for each entry until you get a matrix of scalar products of every possible combination of vectors.\n",
"Matrix multiplication is really just an extension of the dot product. So first it is important to know what a dot product is. In a geometric sense, the dot product between two vectors is defined as the product of their lengths multiplied by the cosine of the angle between them, this can be visualized pretty well in [this image.](_URL_1_) Here there are two black vectors **X** and **Y** with their tails (their starting point) at the same position. Then there is a third red vector which is a projection of vector **X** onto vector **Y**, the length of this red vector (NOT the vector itself) is the dot product between **X** and **Y**. \n\nOk, so you know what a dot product is but what does this have to do with matrices? Well, we're getting closer. If we do [some math](_URL_0_) we can show that the dot product between two vectors can be written a [little differently like this.](_URL_2_) Now the series format can be a little scary so as a simple example let's take two vectors **A** = [1, 2, 3] and **B** = [4, 5, 6] see what the dot product is. **A** • **B** = 1 * 4 + 2 * 5 + 3 * 6 = 32. So now you can calculate a dot product. But actually, you did matrix multiplication, only in this case you multiplied a 1x3 (1 row by 3 columns) matrix with a 3x1 matrix to get a 1x1 matrix.\n\nNow, what happens when you make your matrix bigger? It's really pretty simple but we need to be careful how we do it. Did you notice that a 1x3 matrix multiplied by a 3x1 matrix gave a 1x1 matrix? Well it turns out we can only multiply matrices A and B (A*B) if the columns in matrix A equal the rows of matrix B. Wikipedia states it well as \"if A is an n × m matrix and B is an m × p matrix, their matrix product AB is an n × p matrix, in which the m \nentries across the rows of A are multiplied with the m entries down the columns of B\". \n\nSo it is helpful when starting matrix multiplication to determine what size matrix you are going to get. If you have a 2x3 matrix called matrix F and 3x2 matrix called matrix G we know that it will multiply since 3=3 and we know that we will get a new matrix that is 2x2 that we will call matrix H. Now all we need to determine is what the value in each slot of the 2x2 matrix is going to be. \n\n Matrix multiplication of F*G = H\n F is 2x3 matrix, G is a 3x2 matrix and H will be a 2x2 matrix\n Row 1, column 1 of H will be the dot product of row 1 of matrix F and column 1 of matrix G. \n Row 1, column 2 of H will be the dot product of row 1 of F and column 2 of G.\n Row 2, column 1 of H will be the dot product of row 2 of F and column 1 of G.\n Row 2, column 2 of H will be the dot product of row 2 of F and column 2 of G.\n\nTo summarize, you are doing the dot product between the rows of the first matrix with the columns of the second matrix. \nIf we have two really large matrices and want to know what will be in row 12 column 45 of their product. We do the dot product of row 12 of the first matrix with column 45 of the second matrix. So the best way to do matrix multiplication is first learn the dot product, then all you need to do is keep track of which row you are multiplying by which column and your value will go in that row and column of your solution.\n\n(Edited for formatting)\n"
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2y6don | How large could an iron cube floating in zero gravity be before its own gravity would start to re shape it into a ball? | askscience | http://www.reddit.com/r/askscience/comments/2y6don/how_large_could_an_iron_cube_floating_in_zero/ | {
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"Consider asteroids (not metallic iron, but this is the best I can come up with). They are irregularly shaped as they are small, but if they become large enough, their own gravity will force them into spherical shapes. That is the reason planets are spheres, and it's the reason there is a limit to how tall a stable mountain can be on a given planet.\n\nThink Ceres, the largest known asteroid, with a diameter of about 950 km. Vesta is the next largest, at 525 km. Ceres is nearly spherical, and Vesta isn't quite. However, Vesta is definitely not irregularly shaped, meaning its own gravity is affecting it. Sorry I can't give you a mathematical answer/derivation, but the answer for rock is somewhere between 525 km and 950 km. More dense materials will have a smaller answer.",
"2nd year Physics undergrad student here, currently in my first Astrophysics course. The equation for Hydrostatic Equilibrium (when a body becomes spherical from its own gravity) is given in one text to be dP/dr=-(GMp)/r^2, with P as internal pressure of a body, r as the radius of the body, M the mass of the body, and p (rho) the density.\n\nI'm still a bit weak on differential equations, but this seems to imply that Hydrostatic Equilibrium relates to the mass, density, and radius of a body. Is that correct? ",
"I read that Einstein said a chunk of matter 30 meters in diameter would noticeably produce it's own gravity in a vacuum. Dust would start to collect on the surface. For it to start creating a large amount of heat in the center to start rounding itself out, it would need to be much much bigger. ",
"When giving public astronomy talks we typically cite about 1000 kilometers for hydrostatic equilibrium. This is of course dependent on the material. Icy bodies are about half that, something made of pure iron would likely be more. I'm not sure if you are looking for an answer in the context of large bodies, e.g. planets, asteroids, comets, or stars for that matter. If you are interested, the wikipedia article on hydrostatic equilibrium gives a decent explanation. _URL_0_",
"This type of question actually comes up planetary science. For example, part of the definition of a [planet](_URL_0_) according to the IAU is that it \"has sufficient mass to assume hydrostatic equilibrium (a nearly round shape)\". \n\nIgnoring a lot of the nuance of your question and just looking at it in simple terms, you could approximate that the cube will become spherical when the surface gravity exceeds the strength of the iron (you'll have to ask an engineer *which* strength to use properly, but I'm just going to use the [tensile strength](_URL_1_) for argument's sake). \n\nSurface gravity = mass * (distance from center)^-2 \n\nNow if you want to do this properly it gets even trickier, because calculating the gravitational force on the corners of the cube can be a bit slippery. However, astronomers love to make assumptions that simplify the math, so lets just pretend it behaves like a sphere.\n\nSo we have surface gravity = density * radius^3 * (distance from center)^-2\n\nWith the liberal assuptions I've made, we can treat the radius of the cube and the distance from the center of any given point as the same, so we just have:\n\nSurface gravity = density * radius\n\nSo when the density * radius is equivalent to the strength of the iron, we can assume that it is has deformed into something maybe sort of resembling a sphere. Taking iron's mechanical strength as 200 MPa and its density as about 8 g/cm^3, you'll start getting serious deformation **around 25 km** in \"radius\". \n\nObviously, there were a ton of simplifying assumptions that went into that calculation and it doesn't fully answer your question. In reality, you'll get some deformation much earlier, and you'd probably have to go much larger for it to become truly spherical. But hopefully that at least gives you a rough idea of the situation!",
"Iron yields at about 9 GPa in compression, which means above this pressure it will behave plastically. Crucially, this is the only criterion we need to reshape cold solid iron. Not by melting points, or however asteroids formed.\n\nNow 9 GPa is about 900 million kg per square meter, and iron is about 8000kg per square metre. So, if we had 113km of iron in a tower, on earth this would make the bottom of the tower yield plastically and reshape. That means a sphere 225km across would start to reshape in the centre. Except... Oh dear we've used earth gravity all this time. A cube of iron in space would need to be crushed by its own gravity, which is a much harder thing to achieve. Its early in the morning so I'm going to pass the baton for someone to include G in all this, but reasonably I can say you'd need a cube much larger than 225km a side.\n\nEdit: this is all super fuzzy because iron varies drastically in strength depending on the impurities. Perfect iron is ridiculously soft so I assumed a decent carbon content for the yield point."
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cp15qe | what do scientists means when they say that the "big bang happened everywhere and not at one single point"? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cp15qe/eli5_what_do_scientists_means_when_they_say_that/ | {
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"When we look at the universe we see that the distances between far away things are getting larger. This means that a long time ago they were smaller. If we use math and scientific observations we find that the universe was so small that it was basically a single point about 13.7 billion years ago. It’s hard to think about because we assume when something gets bigger it expands into something but the universe itself is expanding.",
"The big bang was an expansion of spacetime itself, not an explosion of matter. So don't think of it like a firework going off, flinging stars in all directions. Think of it like inflating a balloon.\n\nImagine drawing a bunch of dots on an uninflated balloon, then blowing it up. All of the dots get further away from each other as the balloon material stretches, but none of the dots are actually moving relative to the balloon. So imagine the dots are the \"stuff\" the universe has in it (stars, galaxies, gas, etc.) And the balloon material is the intervening space. There's not really a \"center\" to the expansion, because the material is stretching *everywhere*.\n\nThe balloon is sort of a 2D universe expanding in 3D space, so it's not a perfect analogy, but it sort of gets the idea across."
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146go5 | why do condoms not always prevent the spread of std's? | What's the deal with that? It acts like a barrier, so why do some diseases still get through? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/146go5/eli5_why_do_condoms_not_always_prevent_the_spread/ | {
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"Sometimes condoms break.\n\nSome STIs can spread through skin to skin contact, and not all infected skin is always covered by a condom.",
"Also, people.\n\nThe effectiveness rate of prophylactics or birth control would be higher if not for user error as well. "
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|
371397 | Why did the Japanese not follow up successes in 1941 with an attack on Australia crushing allied forces and bases there? | No professor has had an answer | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/371397/why_did_the_japanese_not_follow_up_successes_in/ | {
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"There were plans made for such an attack. In 1941 and early 1942, Australia posed a major threat to Japanese plans. Troops and ships escaping from the Dutch East Indies could flow southwards to bases in Western Australia. Aircraft based in the Northern Territory could interfere with Japanese movements towards Papua New Guinea, and of course, Australia could provide a base for an Allied counterattack. \n\nThe Imperial Japanese Navy had a doctrine that sought to keep the Allies consistently on the defensive. To this end, they planned attacks into the Indian Ocean, and towards Hawaii with Midway as an objective. During this time, they also drew up plans for an attack on Australia. Plans for this were in place, and being pushed by the Navy's general staff as early as December 1941. These plans sought to capture several strategic positions on the northern and north-Eastern coasts of Australia. As it was considered difficult for Australian troops to reach these locations, it was thought that these locations could be captured with a minimum of shipping and expenditure of troops and materiel. (The lack of strategic mobility on land came from a lack of rail lines and roads to much of the north coast) Navy estimates suggested that between 45,000 and 60,000 men would be needed to capture their chosen targets. \n\nHowever, the Army had a different outlook. Their commitments in China, Manchuria and South-East Asia made it difficult to find the men needed for further expansion and offensives. Instead, they preferred a defensive strategy, which they felt more fitting with Japan's capabilities. They believed that an invasion of Australia would need to capture more of the eastern coast, which was more heavily defended. Their estimates for the numbers of troops needed for such an invasion were closer to 150,000 to 200,000 men. This number was impossible to find without heavily weakening the Japanese force in Manchuria, which the Army was always unwilling to do. In addition, they calculated that 1.5 - 2 million tons of shipping would be needed to support these troops, an amount of tonnage that could not be found without destroying the foundations of the Japanese war economy. Realising the need for offensive operations against Australia, they instead proposed a strategy based around cutting its lines of communication with the USA, by taking New Caledonia, Samoa and Fiji. They were supported in this project by Japanese PM Hideki Tojo, who was always opposed to an invasion of Australia.\n\nThese two sides fought it out in bitter bureaucratic warfare through February and early March 1942. An Imperial Liaison Conference on the 7th March made only oblique references to an attack on Australia, with its report making statements that could be referenced as supporting an attack, but concluding that Japan should be \"building a political and military structure capable of withstanding a prolonged war\", phrasing that implies caution about opening new fronts. However, on the 13th, a new strategic plan was reported to the Emperor. This new plan relegated an attack on Australia to \"a future option to demonstrate positive warfare\", with the qualification that the situation with the Soviet Union and China allowed it. Instead, the Army's plan, modified by the capture of Port Moresby, was to be followed. \n\nUnfortunately for Japan, they wouldn't get a chance to put these plans into action. The Battle of the Coral Sea scuppered the attack on Port Moresby. Midway caused a postponement of the attacks into the South-West Pacific, and allowed the US to intervene with the preliminary attacks into the Solomon Islands.\n\nReferences:\n\nBrown, G., Anderson, D., *Invasion 1942? Australia and the Japanese Threat*, _URL_0_\n\nFrei, H. P., *Japan's Southward Advance and Australia*"
]
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"https://www.aph.gov.au/binaries/library/pubs/bp/1992/92bp06.pdf"
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|
6itpij | What is this red line on the left side of the Sun? | _URL_0_ | askscience | https://www.reddit.com/r/askscience/comments/6itpij/what_is_this_red_line_on_the_left_side_of_the_sun/ | {
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"It only appears in a single frame (which are about 12 seconds apart) so best guess is that the bright spot is the impact point of a cosmic ray, these bright points are called hot pixels. As for the trail leading from it, it was a big enough or lucky enough instance that the pixel was very oversaturated and electrons from it bled down the column of pixels on readout.\n\nIt could also be that the vertical orientation is coincidence and the trail is a reflection of path the cosmic ray took through the detector but such trails, while common, generally cause the detector to be overexposed across the entire length of the trail rather than just at one end. \n\nEither way it is certainly an instrumental effect rather than an observation."
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"https://beta3.helioviewer.org/?date=2015-06-14T14:48:26.000Z&imageScale=2.42044088&centerX=-240.22875734000002&centerY=-99.8431863&imageLayers=%5BSDO,AIA,304,1,100%5D&eventLayers=&eventLabels=true"
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3b7xxe | there are billions of people that have died since the current form of burial has been around. so why isn't the world littered with cemeteries? | I feel like there should be way more cemeteries around judging by the amount of people in the world and the amount of people that die everyday. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3b7xxe/eli5there_are_billions_of_people_that_have_died/ | {
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"Bodies and coffins decay. Depending on the soil, it doesn't even necessarily take that long. I have personally worked in cemetaries only around 100 years old where the only traces of burial are soil staining and a few sturdier artifacts. \n\nCombine with that, in places where land is at a premium, alternatives strategies have been made, such as exhuming the long buried to make room for the new, burying over/under/amongst existing burials, and even sharing grave space among multiple burials. ",
"It's actually a great question because of number you have to bury every year has actually been a great problem overtime.\n\nIn Paris, we have a 200-miles network of tunnels that served at some point as catacombs and where up to 6-7 millions bodies are buried up, we dumped all those bodies underground because the mass graveyards where the poors ended up were just too full.\n\nOtherwise, as others have already said, bodies and coffins decay overtime and I don't know if it's something worldwide but you're not expected to be buried forever, you actually have to pay to renew the ownership of the graves of your ancestors or at some point, their body is cremated or something (can't remember the actual details, I don't really want to think about that :p)",
"1 billion x 20 square feet = one square less than 27 miles on each size = 1/2 of a Rhode Island\n\nThat a lot of space, but is still very small compared to the surface of the earth.\n\n",
"Find Hawaii on a map. To bury 7 billion people in 8 foot by 4 foot graves would require about 8000 square miles of land. That's only twice the size of Hawaii's big island.\n\nLook at that island on a map, and imagine twice that land area scattered around the entire face of the planet. It's not as much space as it sounds when compared to the entire globe."
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4k2753 | smartphone progression getting slower. | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4k2753/eli5_smartphone_progression_getting_slower/ | {
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"One reason is marketing.\n\nCompanies want you hooked on their brand, so they will push out product with slightly better specs each year to make sure people are upgrading.\n\nAs far as the technology itself, the first touch screen smartphone with a mass release was the iphone, and this was only 9 years ago.\n\nLook at how far advance the first one was compared to the most recent release and the jump is huge.\n\nIf you go 9 years into the future and take the most current one today, and do the same thing, you will again likely notice a massive increase in capability.",
"Hardware can only improve so fast. As things get better, the room for improvement is smaller.\n\nS1 > S2 was a .2ghz increase in processor speed, with 2 cores. Same for S6 > S7, but with 8 cores. As a percentage, it's a smaller increase.\n\nS1 > S2 was a 512mb increase in ram, S6 > S7 was 1024mb. Again, a lower percentage increase even though it's a bigger absolute increase.\n\nIn both cases, they share similar screens, features, sizes, batteries, etc.\n\nMoral is, the more they improve, the less an upgrade feels like an upgrade. Adding .2ghz to processor speed feels like a lot when going from 1.0 > 1.2 (20%), but not much when going from 2.1 > 2.3 (a less than 10% difference)."
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2gn3qs | If Earth's rotational speed decreased, then would the strength of the Earth's magnetic field decrease? | Is there a connection between the rotational velocity of a magnet/Earth and the field it produces? | askscience | http://www.reddit.com/r/askscience/comments/2gn3qs/if_earths_rotational_speed_decreased_then_would/ | {
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"\nEarth's magnetic field is not produced in the same way as permanent magnets (like fridge magnets) creates their magnetic field. The theory behind earth's magnetic field is called [dynamo theory](_URL_0_) and the rotation of earth is quite important for that matter.\n\nThe basic concept needs three components: An electrically conductive fluid medium (as earth's outer core); An internal source of energy to create convective currents in such fluid (basically the inner core being hotter than the outer core); And finally a rotational movement of the whole system, creating a Coriolis force that provides a rotational force that organizes rolls in such convection currents.\n\nIf by magic earth would cease to rotate, the magnetic field wouldn't cease immediately, but it would start to slowly decrease untill the convection currents in earth's outer core would loose their rotational coherence."
]
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"http://en.wikipedia.org/wiki/Dynamo_theory"
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|
43c8f8 | why are the voices in peoples heads so negative? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/43c8f8/eli5_why_are_the_voices_in_peoples_heads_so/ | {
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"text": [
"That's actually not universal. \"The voices\" seem to be cultural and are different depending on the society. "
]
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||
4t1bjl | What were old mattresses made from? | As I rolled around on my very comfortable mattress this morning I wondered what mattresses were made of in say the 1200s. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4t1bjl/what_were_old_mattresses_made_from/ | {
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"The first mattresses of the Neolithic period were made of animal skins, possibly supported by leaves, grass, or hay. Later in history, everybody had their own types mattresses, Persians would use goat skins filled with water, while Egyptians used bundles of palm leaves. 3,000 years later, Romans slept on bags filled with hay or wool, sometimes reeds. If you happened to be in a wealthy neighborhood you would find the rich folk sleeping on beds stuffed with feathers.\n\nDuring the Renaissance, beds mostly consisted of mattresses stuffed with straw or feathers. In the early 1700s mattresses are stuffed with cotton or wool. During the mid 1700s we start to get mattresses that we would recognize today (bed frames come about, mattresses are buttoned). In 1865, the first coil springs for bedding are patented, and in 1871 German inventor Heinrich Westphal invents the innerspring mattress. Rather sadly, he dies poor, never profiting from his invention. In 1873 the waterbed is invented, as a sort of hydrotherapy for back problems. In the 1930s, innerspring mattresses become commonplace in American homes. 20 years later, foam rubber mattresses are introduced as an alternative to other artificial fillers. In 1999, the queen size mattress is the most popular choice for mattress size in America. That brings us to today, were we can sleep comfortably knowing that we've come a long way from animal skins stuffed with hay."
]
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|
6eusz5 | Is there a difference between turning electronics off with power button versus unplugging them to turn off? | The reason I ask:
I bought a few "wifi plugs", where I can control appliances on/off with my phone (like my TV, air conditioner, and coffee machine).
I noticed the TV doesn't like being unplugged and takes a bit longer to boot up afterwards. Is there an engineering reason for this? | askscience | https://www.reddit.com/r/askscience/comments/6eusz5/is_there_a_difference_between_turning_electronics/ | {
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"When you switch off a TV by the remote, it's actually going into \"standby mode\" where some components are kept \"warm\" in order to switch on faster next time. When you unplug a TV, or switch it off at the socket, this doesn't happen and the components \"cool\" right down. ",
"Yes, there is a difference. Most of the bigger electronics (TV, anything with a remote) have a standby mode that they will go into when you press the power button. This leaves a relatively low power circuit on to look for commands from the remote, allowing for a fast start up time (on a TV, for example). Unplugging devices like this will cause them to completely turn off, and the next time you plug them in will have to start up completely from scratch. Think of standby as similar to a laptop hibernating, versus that laptop turning on for the first time.\n\nOther electronics that don't have a remote, necessarily, like a razor or hairdryer, actually still draw some power even when they are functionally off. You can test this will something like a Kill-A-Watt. This isn't a standby mode, but usually results from cheap power supply circuity and inefficiencies in the design that still passively draw power when the load (device) is inactive.",
"The off switch for many devices doesn't just open the power circuit. There's usually at least some kind of simple controller that raises a signal when you press the button that alerts the device that it should power down gracefully or enter a low power mode. They can also force the power off if held. If you just cut power, it may be in a bad state, and require some additional integrity checks upon startup.\n\n[Here](_URL_0_) is an example of such a controller that I've used on some projects.\n",
"Time for a story.\n\nOur barracks had a space heater with a fan. Once we've turned it off by pulling the plug. It melted and broke down. Turns out, you're not supposed to do this. If you turn if off with the power button, the fan keeps working for a few more seconds, cooling the heater down, which is a safety feature to prevent meltdown. Pulling the plug doesn't let it do that.\n\nSo, yeah, it may not matter for some devices, but it's still a bad general practice to unplug a working device."
]
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49prrr | why is there still a charge for video games that were made by developers that go out of business? | e.g. Irrational Games, Lionhead Studios (in the future)
I imagine it has to do with the fact that its not the developer that gets paid directly but rather the publisher, who then distributes the portion back to the developer. If that's the case then if a dev goes under, does the publisher get to retain all of those generated sales? If a developer serves as their own publisher and then folds, could they distribute their games openly/freely henceforth?
P.S. This doesn't need to be a literal ELI interpretation here, as per the rules.
Thanks for the responses y'all. I was unaware of "abandonware," so definitely learned something. It seems like the succession for obtaining sales for something like the Bioshock franchise hypothetically would fall back onto 2K games, or Microsoft for the Fable franchise. Thanks again! | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/49prrr/eli5_why_is_there_still_a_charge_for_video_games/ | {
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"When studios go under, or are forced to fold their IP usually gets auctioned out. The owners of the IP would receive profits from all sales of products the IP they bought covers.\n",
"It all depends on who has the right to distribute the game. The original copyright holder can give permission or transfer ownership altogether. You are right that if it's the publisher, it doesn't matter when the developer goes out of business. Video game contracts can be very complicated, with many conditions and many different parties involved, so this really depends on the individual situation.\n\nHowever, even if whoever has the distribution rights goes out of business, a game is often still for sale--this is because copyright is an asset that can be sold in a bankruptcy sale or similar deal. A completely unrelated company might have bought up the game when the developer or publisher dissolved, and continue to receive a cut of sales.\n\nSometimes it is no longer clear who owns the rights to a game. This kind of software is called \"abandonware\"--people tend to freely share abandonware, because even though it is technically protected by copyright, there is no party asserting their copyright to prevent it.",
"The rights to those games are almost always still owned by someone. For example Lionhead is part of Microsoft, so even if Lionhead goes out of business, Microsoft still has the right to sell games that Lionhead made.\n\nIf a publisher goes under, then usually someone will buy the rights to their games. Although they may not be interested in continuing with the costs of distributing the game, so it could potentially result in games being withdrawn from sale.\n\nThere have been some cases where the rights to a game has ended up in the hands of an individual who has decided to release the game into the public domain, or otherwise made them available for no charge. But it's rare, and a lot of games like that are old and obscure.",
"The licenses for those games are still owned by someone.\n\nMicrosoft owns the licenses for Fable, EA owns the licenses for Battlefront, etc."
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95jz14 | I there are blind and deaf people, are there any people with no sense of taste? | askscience | https://www.reddit.com/r/askscience/comments/95jz14/i_there_are_blind_and_deaf_people_are_there_any/ | {
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"Short answer: yes, and here's a [first-hand account](_URL_3_).\n\nLong answer: It's tricky to separate taste and smell. The loss of the sense of smell is a condition called anosmia. The loss of the ability to taste without losing the ability to smell is less common. Here are two quotes cited by the [Anosmia Foundation](_URL_0_):\n\n > True taste disorders are uncommon. A taste disorder may present as a loss of taste, that is the loss of the ability to detect salt, sweet, sour, and bitter or it may present as an abnormal taste in the mouth such as a bitter taste, an unpleasant taste, or even an electrical sensation. Loss of taste is most commonly caused by an interruption of the nerve to the tongue. This can happen as a result of surgery, tumors, or even dental injections.\n\nIn truth, the interplay between smell and taste is complicated. I'm not a biologist, so here's someone who can explain it better than me:\n\n > In my opinion, arguments about taste and smell are difficult to keep clear unless you upgrade the vocabulary. Start with the ground rule that \"taste\" will only be used for the five qualities obtainable from the taste receptors of mouth and throat: salt, sweet, bitter, sour, umami. I know of no good evidence for any further taste qualities. All other experiences that one gets from food (or other objects) in the mouth should be referred to as \"flavor\". Flavor is regarded as the result of gustatory-olfactory interaction. **Anosmics can taste quite well -- nothing missing there. But they cannot experience flavor.**\n\nIf you want to go further down the smell/taste rabbit hole, check out this [Mental Floss](_URL_1_) piece.\n\nIn addition to developing anosmia gradually over time, roughly 1 out of every 10,000 people is born with congenital anosmia, meaning they never have the ability to smell. According to the [NIH](_URL_2_), congenital anosmia can occur in conjunction with other disorders (like Kallmann syndrome) or on its own.\n\nSo to answer your question... yes, 1/10,000 of the population is born without the ability to smell, which means they cannot experience taste in the same way as the rest of us.",
"There is a seizure medication called Topiramate (generic is Topamax). One of the side effects that is very common are \"taste perversions\". Soda in particular may have a \"flat taste\", meaning is doesn't seem to have any carbonation, even though to everyone else it does.\n\n"
]
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"https://www.anosmiafoundation.com/taste.shtml",
"http://mentalfloss.com/article/30737/if-you-can%E2%80%99t-smell-can-you-taste",
"https://rarediseases.info.nih.gov/diseases/9486/congenital-anosmia",
"https://www.nytimes.com/2003/09/22/health/a-matter-of-taste-i-was-a-middle-aged-anosmic.html"
],
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] |
||
19spr8 | Are all members of one species descended from a single individual? | I heard that all of humanity may or may not be descended from one couple and that it was impossible to not be because we have certain genes in common. Thanks. | askscience | http://www.reddit.com/r/askscience/comments/19spr8/are_all_members_of_one_species_descended_from_a/ | {
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"No, speciation usually happens when two populations of the same species are physically (or in some other fashion) separated and different environments lead to increasingly different traits and genetic makeup eventually leading to sufficiently low interbreeding success.",
"No, absolutely not. In the case of humans, you can trace individual chromosomes to single individuals. You can trace the mitochondrial chromosome, and you can trace the non-recombining portion of the Y chromosome. This is because the mt chromosome is inherited only from your mother and the Y chromosome is inherited only from your father; they propagate **clonally**, that is, the genes on them are inherited as a unit and do not segregate independently.\n\nBecause of the way that clonal evolution works, over a long enough timescale, a single clone will always grow to become the only one in the population (even if there is no selection at work). Let's make a little cartoon example to illustrate:\n\nLet's say there are ten women in the population, and ten men. Each generation, they mate randomly and produce ten male and ten female offspring. Sometimes one of the men will have two children; sometimes one will have three; sometimes one will have none, and the same for the women.\n\nLet's examine the first generation's Y chromosomes. If each one of the men had one son, then each one of them will pass on their Y chromosome, and all ten original Y chromosomes will continue to exist in the population. But if one of the men has two daughters instead, his Y chromosome will NOT be passed on. Now the population only has nine unique Y chromosomes in it, for all remaining time. That Y chromosome is lost forever, even though the number of men in the population is the same. This phenomenon is called **Muller's ratchet**. Once the ratchet clicks, that variant is irrevocably lost, and over time the population becomes less diverse. Eventually, the ratchet will click enough times that only a single Y chromosome of the original ten remains, and from that point on, all men will have this Y chromosome (and can thus trace their origin to a single individual).\n\nOther chromosomes, however, are free to recombine, and they do so liberally, so that any given chromosome in any given individual is a combination of a large number of ancestral chromosomes. It is therefore impossible to say that a single individual produced, say, your chromosome 1.\n\nWhat IS true is that every individual mutation that fixes in the human population most likely had a single point of origin (discounting rare recurrent mutations, which might have occurred in a subset of mutations). For example, there are a handful of mutations that are responsible for light skin color in Europeans. Each one of these mutations emerged in a single individual, and this variant was propagated by selection to its current high frequency.",
"astazangasta's explanation of mitochondrial Eve/ Y chromosome Adam is good, and colechristensen's comment is accurate regarding speciation in general. However, I'd like to point out one case where an entire species can be descended from a single individual: [polyploidy](_URL_0_), usually in plants. \n\nMost species have two copies of each chromosome (called diploidy). These copies are separated when gametes are produced, so sperm and eggs have a single set (haploidy) that goes back up to a full set after fertilization. However, sometimes the chromosome pairs fail to separate and you get diploid egg or sperm. If fertilization happens with those in humans or (most) animals, the zygote won't survive and a miscarriage will occur. If this happens in plants, on the other hand, you can get triploid (3 full sets of chromosomes), tetraploid (4 full sets) or more, and still have survival. \n\nThis polyploidy event means the offspring can't reproduce with the parent plant-the chromosome numbers don't line up. But plants can self-pollinate, meaning a species that's the result of a polyploidy event are all descended from that first polyploid plant."
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6fayu5 | Unknown origin of postcard from WWII. | My grandmother showed me a letter from her father who was in the U.S. Navy in WWII. I need help figuring out where this postcard is from.
[here is the postcard that she gave me](_URL_0_) | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6fayu5/unknown_origin_of_postcard_from_wwii/ | {
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"This was Ginza Street in Mudanjiang, Manchuria, China. It was under Japanese occupation since 1931, hence the name \"Ginza\" after a district of Tokyo, and the city was called \"Botankou\" by the Japanese. That's the reading of the Chinese characters in Japanese. \n\nThe top of the postcard gives the location read right to left: Botankou, Ginza Avenue. (牡丹江 銀座 通り) (I've written it here left to right in the modern way)\n\nThe shop signs are in Japanese, and your great-grandfather mentions that a lot of the buildings aren't there anymore, so I guess this was a postcard left from its heyday as a shopping street. Here's a [1942 photograph of the same street](_URL_0_) from Wikipedia.\n\n**ETA:** I'm rather interested what your great-grandfather was doing there in September, since Mudanjiang a) is inland b) was liberated by the Soviet Union in August. \n\n**ETA 2:** This may help you with further research. the battle that took place in August is written as \"Mutanchiang\" in most sources, according to older transliteration rules. The battle was very destructive, no wonder a lot of the buildings were gone when your great-grandfather wrote your grandmother."
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|
ih7dz | Can someone explain body fat's role in coronary heart disease? | From what I understand, coronary heart disease is usually caused by fatty material collecting on the walls of your arteries to form plaque. The artery gets more narrow and less elastic, so your heart has to work harder to pump the blood through it. This can cause tissue damage, blood clots, aneurysms, stokes, heart attacks, ect.
Does having high amounts of body fat increase the amount of plaque in your arteries?
Or does body fat effect your heart in some different way that I am not aware of? | askscience | http://www.reddit.com/r/askscience/comments/ih7dz/can_someone_explain_body_fats_role_in_coronary/ | {
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"I studied this a bit during my undergraduate thesis on heart imaging so I'll put a few words in. \n\n1) The heart itself is a muscle and has smaller arteries to supply it. If the artery becomes blocked, then the constantly working heart exhausts itself of nutrients and begins to \"die\". Many times after a heart attack, all that is left is basically dead tissue that can't pump or conduct an electrical signal so the heart begins to remodel itself to compensate. Often the patient will end up with an enlarged heart and arrhythmia (abnormal beat).\n\n2) The aorta is basically the giant artery that exits the heart and then branches off to the entire body. This is supposed to be an elastic artery that helps regulate blood pressure throughout the entire body. The aorta of an obese person or of a smoker will be a lot stiffer and this has consequences in the entire body and major organs.",
"Sorry for the long winded response, wanted to give you some background too.\n\nThe body is fed through a system of blood vessels with the heart being the pump. The major organs are connected in [series](_URL_1_) which means that the more things connected the lower the resistance (blood pressure) will be.\n\nFat is also an organ and if I am fat enough the resistance in the circuit will drop and blood pressure will drop. The body has sensors in the kidney to make sure there is sufficient blood pressure for sufficient perfusion of organs. If blood pressure is too low then the organs will not get enough blood to maintain normal function. The kidney releases chemical signals ([renin](_URL_0_)) to boost the blood pressure by retaining water and salt.\n\nThis extra fluid makes the heart work harder and require more nutrients. The excess fat also increases the level of free fatty acid in the blood stream which has a tendency to form streaks of fat in arteries. The most common being the aorta but since it is very large it does not pose much threat there but does pose a threat in the coronary vessels. As the fat accumulates it damages the vessel lining which causes the binding and deposition of macrophages and platelets. Over time this deposit can grow very large and occlude the artery (you need a > 80% blockage to feel symptoms). Voila, this is coronary heart disease. Symptoms stem from the fact that parts of the heart are no longer getting sufficient energy to keep up with their work demand - > Chest pain aka Angina.\nComplications from CHD include heart attack, congestive heart failure, stroke, and death.\n\n\nInteresting stuff:\nHigh density lipoprotein (HDL) is considered the good cholesterol because it sucks up fatty streaks from your arteries preventing arterial damage."
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"http://en.wikipedia.org/wiki/Series_and_parallel_circuits#Series_circuits"
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pr45x | When brain cells are replaced, do the memories held by the old brain cells come back with the new ones? | askscience | http://www.reddit.com/r/askscience/comments/pr45x/when_brain_cells_are_replaced_do_the_memories/ | {
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"Wow. This is a big question.\n\nThere'll be stacks on by a heap of people shortly, so just a few short points.\n\nFirst, it's unlikely that single neurons hold memories. The theory these days that memories are rather stored in a distributed network of neurons. The information likely represented by the relative strengths and polarities of these connections.\n\nSecond, there are very few parts of the brain where new neurons are born and integrated into the network (olfactory bulb and hippocampus), which is why brain injury can be so problematic.\n\nThe hippocampus is an interesting place, because it's important for learning, memory and navigation - where you need new neurons to be inserted into the brain to help consolidate new memories. I suggest you have a read of the wiki articles ([neurogenesis](_URL_0_) and [hippocampus](_URL_1_)), they're pretty nice.",
"You're pushing at the edge of our understanding on all levels with this question, both to do with how memories are stored, and also how new brain cells integrate into the existing network.\n\nAs TaslemGuy rightly states, an individual neuron is highly unlikely to store a memory (though to be honest, we've never actually tested that theory). However, in some areas of the brain (dentate gyrus granule cell layer) there is a significant formation of cells that are likely to be involved in memory in some way. That is to say, if your dentate gyrus was completely removed, it is likely your ability to recall facts would be significantly hampered (though we don't actually KNOW this either).\n\nAlso, in areas of the brain where there is a large amount of neurogenesis (new brain cell formation) there is no evidence that there is an abnormal about of cell death. i.e. it doesn't appear that new neurons are replacing old ones.\n\nWhat do we know about about how new cells in the dentate gyrus integrate? Well there is a lot of work going on here. Well we know that adult born neurons grow up to become indistinguishable from their neighbors, but that doesn't mean they like up in any specific way related to how their neighbors are already hooked up. It seems likely that adult born neurons in the dentate gyrus form synapses in similar (though not identical) ways to those formed during pre/early postnatal development. And then are modified by the same rules that form the earlier formed synapses.\n\nThings are a little different if we consider areas where damage has taken place. Here stem cells move into the damaged area, and differentiate. However, most of them don't turn into neurons, but into glial cells. Exactly what the few % that do turn into neurons do, we don't really know."
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"http://en.wikipedia.org/wiki/Hippocampus"
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jikho | when do i properly use the word "literally?" | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/jikho/when_do_i_properly_use_the_word_literally/ | {
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"Most of the time when someone uses the term literally wrong, what they mean is figuratively, so the best way to answer this I think is to show the difference between them! Literally means that this *actually happened*, where figuratively means that its an exaggeration.\n\n*\"I waited in line for Metallica tickets for so long my head literally exploded.\"* This would be correct only if your head actually exploded, which would probably make it difficult to be telling the story afterwords, right?\n\nSo when do you use literally? when you're telling a story where someone could misunderstand you and think you are being figurative or exaggerating when you are not. *\"Sorry I'm so late getting back from the Metallica concert, but traffic was gridlocked for literally an hour\"*. This is true, if traffic really was gridlocked for an hour!",
"When you see a fork-lift lifting a box of forks.",
"When you mean exactly what you say. \n\nIf you say \"It was literally a clusterfuck\" then you mean \"I was in a situation in which a bunch of people took their clothes off and had sex together in a big cluster.\"",
"Most of the time when someone uses the term literally wrong, what they mean is figuratively, so the best way to answer this I think is to show the difference between them! Literally means that this *actually happened*, where figuratively means that its an exaggeration.\n\n*\"I waited in line for Metallica tickets for so long my head literally exploded.\"* This would be correct only if your head actually exploded, which would probably make it difficult to be telling the story afterwords, right?\n\nSo when do you use literally? when you're telling a story where someone could misunderstand you and think you are being figurative or exaggerating when you are not. *\"Sorry I'm so late getting back from the Metallica concert, but traffic was gridlocked for literally an hour\"*. This is true, if traffic really was gridlocked for an hour!",
"When you see a fork-lift lifting a box of forks.",
"When you mean exactly what you say. \n\nIf you say \"It was literally a clusterfuck\" then you mean \"I was in a situation in which a bunch of people took their clothes off and had sex together in a big cluster.\""
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3mse2u | the evolutionary advantage to emotions | Wouldn't not having emotions make is better at survival? Insects, as far as we know, don't have emotions and they seem fine. Side question; Why do we have emotions/feelings? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3mse2u/eli5_the_evolutionary_advantage_to_emotions/ | {
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"Emotions serve as a motivator to engage in survival behaviors. On a basic level, emotions are punishments and rewards inside our own brains, in response to our own behavior. \n\nInsects can get by without emotion (at least, we assume they can't feel emotion-- they don't seem to have the brain structure that we associate with emotion) because they can do everything they need to do, based on instinct. They do not rely upon sophisticated, general intelligence to solve problems. They just do a sequence of stimulus-response behaviors. For another thing, they usually have short lives. Less time to need exceedingly complex behavior in each individual, and less need for long-term motivation.\n\nIn a large, long-lived, highly social, fully sentient animal, intelligence with no emotion would result in an organism that is a danger to itself. \n\nFear is the best example. A person without fear would be MUCH more likely to get too close to the edge of a cliff or near large predators. Cold, unemotional calculation can, in theory, tell you \"don't go near the cliff, you could fall.\" But that is nowhere NEAR as effective as the unpleasant **feeling** of fear. A person or animal experiencing fear will automatically and reliably avoid the thing it fears. It's simpler than going through a bunch of rational thought. EDIT: Also, intelligence alone does not guarantee avoidance of the cliff. With intelligence comes the possibility to question anything and everything. Without emotion, it's far easier to slip into existentialism. An emotionless being might say: \"Yes, I could fall off the cliff and die...but when I think about it, I'm not sure I really understand why that would be so incredibly undesirable.\" In other words, even the urge to survival can be circumvented by thought. Emotions may very well be a way to keep that kind of thing in check. You could spend too much time on /r/philosophy and conclude that life has no intrinsic value...but if you get too close to a 500 meter drop-off, your fear will still almost certainly drive you away. \n\nSame goes for positively motivating emotions, like love or anger. Note that I mean \"positive\" in the sense that the emotion provokes someone toward action, rather than away.\n\nLove and anger, like fear, represent a simpler, more generalized path to motivation than complex rationalization. If you love someone, you'll put yourself in danger to protect them, without hesitation. If you're angry, you'll fight without having to have the reason for a threat explained to you in clear terms.\n\nFor a complex organism that lives for decades, it's just far more efficient to have evolved an emotional system to regulate our behavior, through the secondary actor of motivation. The alternative would be impossibly complex sets of stimulus-response instincts, or a very similar reliance on laboriously thinking through every possible action, in purely logical terms.",
"Emotions are critical to human evolution. Without emotion, no one would fall in love and procreate and defend their babies and nurture them into successful humans, for further procreation.\n\nInsects have intinctual \"urges\" -- to have sex with other insects and care for their young, for example, which fulfill the same evolutionary purpose as more complex human emotions. Human emotions aren't so simple because we have a complex mind that must be able to adapt itself to many different situations in order to be metabolically justifiable.\n\nI guess it's beyond the scope of an ELI5 answer but for a detailed discussion of why we have the emotions we do I recommend reading *The Moral Animal*, by Robert Wright."
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ntz6z | Afghanistan history | I'm looking for books that focus on early Afghanistan history, culture, as well as during the Soviet invasion. I want books that focus on Afghanistan, not foreign powers interested in them (so far I've found books about the Soviets and Americans in the country, but none about what Afghanistan thought and did, as a country and as individuals). Can you help, reddit historians? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/ntz6z/afghanistan_history/ | {
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"I have a book I never finished. Let me go and see if I can find it. Pretty much what you're looking for if I can recall",
"You might like [My Khyber Marriage](_URL_3_) and [Valley of the Giant Buddahs](_URL_6_). They are autobiographical reports by a Scotswoman who married a Pashtun and moved to Afghanistan in the 1920s. [My Life: From Brigand to King--Autobiography of Amir Habibullah](_URL_1_) may also be of interest. It is an as-told-to autobiography of an Afghan brigand who briefly overthrew the King about ten years after the first two books were written. [The Road to Oxiana](_URL_5_) is a bit clunky but offers a Western perspective on Afghanistan in the 1930s. \n\nThe more general [Afghanistan of the Afghans](_URL_7_), written by the husband of the woman mentioned above, focuses a lot of culture and cultural history, [Afghanistan](_URL_9_) is a more general history and this [Afghanistan](_URL_8_) claims to be more about the military history but I haven't read it myself to judge.\n\nIf you want something more contemporary, [The Places In Between](_URL_0_) is a decent travelogue by an adventurer/preservationist/mercenary who walked through parts of the country. It didn't blow me away but it is interesting and most contemporary Afghan books from the West are such trash that this one shines in comparison. The author really did go to areas of Afghanistan about which most people know very little.\n\n[Ghost Wars](_URL_4_) is a popular book that focuses on the US involvement in the area during the Soviet Afghan war. [Taliban](_URL_2_) is another popular book, and focuses on the Taliban in the 1990s and early 2000s. The link is to the second edition which I believe is updated.",
"I have a book I never finished. Let me go and see if I can find it. Pretty much what you're looking for if I can recall",
"You might like [My Khyber Marriage](_URL_3_) and [Valley of the Giant Buddahs](_URL_6_). They are autobiographical reports by a Scotswoman who married a Pashtun and moved to Afghanistan in the 1920s. [My Life: From Brigand to King--Autobiography of Amir Habibullah](_URL_1_) may also be of interest. It is an as-told-to autobiography of an Afghan brigand who briefly overthrew the King about ten years after the first two books were written. [The Road to Oxiana](_URL_5_) is a bit clunky but offers a Western perspective on Afghanistan in the 1930s. \n\nThe more general [Afghanistan of the Afghans](_URL_7_), written by the husband of the woman mentioned above, focuses a lot of culture and cultural history, [Afghanistan](_URL_9_) is a more general history and this [Afghanistan](_URL_8_) claims to be more about the military history but I haven't read it myself to judge.\n\nIf you want something more contemporary, [The Places In Between](_URL_0_) is a decent travelogue by an adventurer/preservationist/mercenary who walked through parts of the country. It didn't blow me away but it is interesting and most contemporary Afghan books from the West are such trash that this one shines in comparison. The author really did go to areas of Afghanistan about which most people know very little.\n\n[Ghost Wars](_URL_4_) is a popular book that focuses on the US involvement in the area during the Soviet Afghan war. [Taliban](_URL_2_) is another popular book, and focuses on the Taliban in the 1990s and early 2000s. The link is to the second edition which I believe is updated."
]
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"http://www.amazon.com/Places-Between-Rory-Stewart/dp/B002IT5OS4/ref=sr_1_1?s=books&ie=UTF8&qid=1325141336&sr=1-1",
"http://www.amazon.com/gp/product/0863040470/ref=oh_o04_s00_i00_details",
"http://www.amazon.com/Taliban-Militant-Fundamentalism-Central-Second/dp/0300163681/ref=pd_luc_sim_01_01_t_lh",
"http://www.amazon.com/Khyber-Marriage-Experiences-Scotswoman-Chieftains/dp/0863040551",
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"http://www.amazon.com/gp/product/0900860995/ref=wms_ohs_product",
"http://www.amazon.com/Afghanistan-Military-History-Alexander-against/dp/0306818264/ref=sr_1_2?s=books&ie=UTF8&qid=1325141153&sr=1-2",
"http://www.amazon.com/Afghanistan-Cultural-Political-Princeton-Politics/dp/0691145687/ref=sr_1_1?s=books&ie=UTF8&qid=1325141153&sr=1-1"
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"http://www.amazon.com/Places-Between-Rory-Stewart/dp/B002IT5OS4/ref=sr_1_1?s=books&ie=UTF8&qid=1325141336&sr=1-1",
"http://www.amazon.com/gp/product/0863040470/ref=oh_o04_s00_i00_details",
"http://www.amazon.com/Taliban-Militant-Fundamentalism-Central-Second/dp/0300163681/ref=pd_luc_sim_01_01_t_lh",
"http://www.amazon.com/Khyber-Marriage-Experiences-Scotswoman-Chieftains/dp/0863040551",
"http://www.amazon.com/Ghost-Wars-Afghanistan-Invasion-September/dp/0143034669/ref=sr_1_7?s=books&ie=UTF8&qid=1325141153&sr=1-7",
"http://www.amazon.com/Road-Oxiana-Robert-Byron/dp/0195325605/ref=sr_1_6?s=books&ie=UTF8&qid=1325141309&sr=1-6",
"http://www.amazon.com/Valley-Giant-Buddhas-Memoirs-Travel/dp/0863040659/ref=sr_1_1?ie=UTF8&qid=1325140790&sr=8-1",
"http://www.amazon.com/gp/product/0900860995/ref=wms_ohs_product",
"http://www.amazon.com/Afghanistan-Military-History-Alexander-against/dp/0306818264/ref=sr_1_2?s=books&ie=UTF8&qid=1325141153&sr=1-2",
"http://www.amazon.com/Afghanistan-Cultural-Political-Princeton-Politics/dp/0691145687/ref=sr_1_1?s=books&ie=UTF8&qid=1325141153&sr=1-1"
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1xwn9q | what is a "house majority whip"? | I'm watching House of Cards | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1xwn9q/eli5_what_is_a_house_majority_whip/ | {
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"\"Whips\" the others in the party into line. \n\nMajority means that he/she is a member of the party that currently holds the most seats in the House of Representatives. Currently, that is the Republican Party. \n\nThe whips are responsible for making sure that whey they put something up for a vote, those in the party are going to follow instructions and vote for it. \n\nThey are the bullies of the party. The strongarms. ",
"The whip is the person who finds out how the members of his caucus plan to vote. And yes, part of the job is getting the members to toe the party line, but the main purpose for the whip is so that you can find out if a measure will pass or fail -- and if you're losing, you can see which votes you need to get, and then they can see what kind of deals have to be made to get those people on board.\n\nSo, the \"House Majority Whip\" would be the person who does that for the majority party in the House of Representatives.",
"Hey, me too! Still on episode one of the new season here.\n\n-------------------\n\n > House\n\nThe House is the House of Representatives. The US government has 3 branches: \n\n1. The Judiciary (judges/courtrooms/etc). They interpret the law.\n\n2. The Executive (the President). They execute the law.\n\n3. **The Legislative (the House and Senate). They create the law.**\n\nThe Legislative branch has two parts: the House and the Senate. In order to create a law both groups have to agree. Once they agree then they \"sign off\" on a bill and send it to the President.\n\nMembers of the House are called Representatives. They are elected every 2 years. There are 435 Representatives. Each state gets a number of Representatives based on how many people live in the state.\n\nMembers of the Senate are called Senators. They are elected every 6 years. There are 100 Senators. Each state gets 2 senators regardless of how big or small their state is.\n\nSo that's the House: one of the 2 groups that is one of the 3 branches of the government. Along with the Senate they create the law.\n\n > Majority\n\nThere are (basically) 2 parties: the Republicans and the Democrats. The majority is the party that has more members. So if there are 60 Democrats and 40 Republicans in the Senate then the Democrats are in the majority and the Republicans in the minority.\n\nIf you're in the majority then you have more power; if you're in the minority then you have less power. \n\n > Whip\n\nThe whip keeps everyone in line. The whip makes sure that the members vote to support their party. The whip can give things (like promotions) or take them away. They make sure that party members vote the way the party wants them to vote.",
"Re: HoC\n\nHe is the #3 guy in the House of Representatives. There is the Speaker of the House (#1), the House Majority Leader (#2), then the House Majority Whip.\n\nHis purpose is to accrue support for the party agenda and ensure that the caucus is supporting the Speaker. It can be embarrassing for the Speaker or Majority Leader to not have the support of their caucus, thus they need an 'enforcer' (Majority Whip) to keep everyone in line."
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5crqep | do all presidents use air force one for campaigning? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5crqep/eli5_do_all_presidents_use_air_force_one_for/ | {
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"While you are the President of the United States ALL airplanes that you set foot on get the call sign Air Force One. All of them. \n\nThe specific plane that you think of as Air Force One is specially designed to suit the needs of the President and so if he is campaigning for re-election or giving speech on behalf of another he will take it, just like he would for any air travel that he has to make. It is part of the job. ",
"Sometimes, but not normally so extensively for someone else (i.e. not their own reelection). Then again, nothing about this past election was normal.\n\nOne advantage the president has is that the presidential airplanes have offices and conference rooms so that the president can still do their official work en route to campaign events.",
"Yes. A sitting president is on the job 24/7, and AF1 is designed to keep him safe and in constant communication with the rest of the government. This applies even when campaigning. Not only that, but any travel he does requires extensive advance prep and travel by the Secret Service, as well as flying in the Presidential limo.\n\nI believe that when running for reelection his campaign is supposed to reimburse some of the costs related to travel that is primarily for campaign purposes."
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ldlkh | What determines the speed of ripples propagating on a surface of water? | E.g., if I drop a giant stone in a still pool of water, it takes a few seconds for the ripples to go even a few metres. Googling hasn't turned up much for me. I'm guessing it's unrelated to the speed of sound in water considering how slow it is. Does it have something to do with surface tension? What property of the water determines how quickly the ripples propagate? | askscience | http://www.reddit.com/r/askscience/comments/ldlkh/what_determines_the_speed_of_ripples_propagating/ | {
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"[Here is a link](_URL_0_) for calculating the speed of a water wave. \n\nThe factors that affect the speed are the wavelength, the depth of the water, and the acceleration due to gravity. ",
"Hey hey. You are correct.\n\nThe speed of sound in water is 1,484 m/s. Sound waves are longitudinal (compression) pressure waves.\n\nA surface wave is a different beast. These are transverse waves where a vertical perturbation is restored by the force of gravity. The speed of a surface wave is determined by the dispersion relation ([wikipedia](_URL_0_)) which, for surface waves, means that they travel at a range of speeds depending on the depth of the water and the wavelength of the wave. On a pond of depth 1m a 5cm ripple travels at 30cm/s.\n\nSurface waves can also be non-linear - see BorgesTesla's comment.\n\nEdit: thanks BorgesTesla for the correction.",
"You have asked a specific question, but it happens to be a special case of a general question that arises all the time in physics. Thus I will restate it:\n\nQuestion: What determines the speed of a wave?\n\nAnswer: This is calculated from the differential equation that you use to model the wave. Linearize the equation and get a relationship between the angular frequency (omega) and the wavenumber (k). This relationship is called the *dispersion relationship*.\n\nFrom the dispersion relationship, you can calculate the phase velocity,\n [; v_p = \\omega / k ;]\nand the group velocity,\n [; v_g = d\\omega / dk . ;]\n\nSpecific to water, see the Wikipedia article on [dispersion in water waves](_URL_0_).",
"The link thebetrayer gives above is very good. However, it does not address real ripples well.\n\nThe site [Water, waves, and ripples](_URL_0_) gets into the theory more, including surface tension, for example:\n\n > Water molecules are attracted and bonded to each other by hydrogen bonds. However, at an air-water surface each water molecule can only bond to water below it. The overall effect is a force to minimize the total surface area. Mathematically this is equivalent to a force proportional to the second derivative of the surface. It is as if the water surface was a thin sheet of stretched rubber.",
"This is the sort of thing I get my undergraduates to figure out, since actually guessing the dispersion relation is a good exercise for understanding a crucial tool of the practising physicist: dimensional analysis.\n\nAs mentioned already, the ripples are gravity driven: a bump on the surface is restored by gravity, and overshoots because of inertia. Thus we need to relate (angular) frequency [s^-1 ], wavelength or wave number [m^-1 ], density [kg] and gravitational acceleration [m/s^2 ]. Thus immediately we see that the density can't be involved because it would bring a mass to the table that nothing else can cancel. Thus we get (frequency)^2 ~ gravitational acceleration * wavelength. This does indeed turn out to be correct for gentle ripples: small amplitude, long wavelength.\n\nThe two main corrections are a depth dependence (which enters primarily as a correction to the constant of proportionality in the form of a function of (wavelength/height)), and surface tension, which gives a non-linearity for sufficiently small wavelengths.",
"[Here is a link](_URL_0_) for calculating the speed of a water wave. \n\nThe factors that affect the speed are the wavelength, the depth of the water, and the acceleration due to gravity. ",
"Hey hey. You are correct.\n\nThe speed of sound in water is 1,484 m/s. Sound waves are longitudinal (compression) pressure waves.\n\nA surface wave is a different beast. These are transverse waves where a vertical perturbation is restored by the force of gravity. The speed of a surface wave is determined by the dispersion relation ([wikipedia](_URL_0_)) which, for surface waves, means that they travel at a range of speeds depending on the depth of the water and the wavelength of the wave. On a pond of depth 1m a 5cm ripple travels at 30cm/s.\n\nSurface waves can also be non-linear - see BorgesTesla's comment.\n\nEdit: thanks BorgesTesla for the correction.",
"You have asked a specific question, but it happens to be a special case of a general question that arises all the time in physics. Thus I will restate it:\n\nQuestion: What determines the speed of a wave?\n\nAnswer: This is calculated from the differential equation that you use to model the wave. Linearize the equation and get a relationship between the angular frequency (omega) and the wavenumber (k). This relationship is called the *dispersion relationship*.\n\nFrom the dispersion relationship, you can calculate the phase velocity,\n [; v_p = \\omega / k ;]\nand the group velocity,\n [; v_g = d\\omega / dk . ;]\n\nSpecific to water, see the Wikipedia article on [dispersion in water waves](_URL_0_).",
"The link thebetrayer gives above is very good. However, it does not address real ripples well.\n\nThe site [Water, waves, and ripples](_URL_0_) gets into the theory more, including surface tension, for example:\n\n > Water molecules are attracted and bonded to each other by hydrogen bonds. However, at an air-water surface each water molecule can only bond to water below it. The overall effect is a force to minimize the total surface area. Mathematically this is equivalent to a force proportional to the second derivative of the surface. It is as if the water surface was a thin sheet of stretched rubber.",
"This is the sort of thing I get my undergraduates to figure out, since actually guessing the dispersion relation is a good exercise for understanding a crucial tool of the practising physicist: dimensional analysis.\n\nAs mentioned already, the ripples are gravity driven: a bump on the surface is restored by gravity, and overshoots because of inertia. Thus we need to relate (angular) frequency [s^-1 ], wavelength or wave number [m^-1 ], density [kg] and gravitational acceleration [m/s^2 ]. Thus immediately we see that the density can't be involved because it would bring a mass to the table that nothing else can cancel. Thus we get (frequency)^2 ~ gravitational acceleration * wavelength. This does indeed turn out to be correct for gentle ripples: small amplitude, long wavelength.\n\nThe two main corrections are a depth dependence (which enters primarily as a correction to the constant of proportionality in the form of a function of (wavelength/height)), and surface tension, which gives a non-linearity for sufficiently small wavelengths."
]
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"http://en.wikipedia.org/wiki/Dispersion_%28water_waves%29"
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"http://en.wikipedia.org/wiki/Dispersion_%28water_waves%29"
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"http://www.scienceisart.com/B_Waves/Waves.html"
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"http://www.scienceisart.com/B_Waves/Waves.html"
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|
3yvv2o | what is a steam arg, and what does arg stand for? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3yvv2o/eli5_what_is_a_steam_arg_and_what_does_arg_stand/ | {
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"ARG stands for \"Alternate Reality Game,\" where the gameplay is layered on top of real life. One notable example is \"I Love Bees,\" an ARG that came out for Halo 2 that had people listening at payphones all over the country, piecing together clues related to the story.\n\nThis may relate to a Valve IP; Valve has done this before with Portal."
]
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[]
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||
8fu75q | Are there naval mines floating around the ocean/rivers from when they were used in wars, similar to how there are leftover landmines in Vietnam? How long do the naval mines last? | For example, the British dropped hundreds of thousands of mines to protect their shipping during WW2 - have those all been neutralized, or are there areas that are no go zones for shipping due to unexploded mines. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/8fu75q/are_there_naval_mines_floating_around_the/ | {
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"I’ve never heard of any such areas and highly doubt they exist. \n\nFirst things first seawater is extremely corrosive. Rust stains on ships are common even before they’re completed. Spend some time on r/WarshipPorn, extensive rust pops up every couple days. In a recent thread some sailors discussed the current *Wasp* class, which is apparently always covered in rust. This is why regular drydockings and painting are essential. \n\nMany museum ships have unfortunately been victims of rust even in a very short time. *Drum* and *Laffey* required extensive repair work, the latter was in such bad condition [her entire bottom had to be replaced](_URL_1_). *Yorktown* has sunk at her moorings and needs a massive cofferdam built around the ship. *Clamagore*, the last GUPPY III submarine left, is due to be sunk as a reef due to neglect. *Olympia* and *North Carolina* are using small mobile systems to do spot repairs on their leaking hulls. And then there’s *Texas*, which is in such bad shape she needs to get out of the water as quickly as possible. The damage is so extensive the foundations under the engines were almost gone, and they apparently nearly fell out of the ship before money dedicated to the dry berth project went to completely replacing those foundations. Most of the ships I mentioned are from WWII and all have been drydocked within the last 40 years (most in the 90s), so we’re talking a similar age. \n\nTake that and apply it to mines. Floating mines long ago flooded and are now on the bottom. Bottom mines long ago leaked. Both have had rust attack their detonators and internal mechanisms, contact, magnetic, acoustic, or otherwise, and are now effectively safe. They won’t explode easily and certainly aren’t a danger to nearby shipping, but you don’t want to go messing with them if you can avoid it. \n\nAnd that’s those that survived the war. Most mines had a shelf life, only good for a few weeks or months before timers or corrosion rendered them inoperative. Yes, mines had timers that automatically made them inactive or only activated them after a certain amount of time, intended to protect the ship laying the mines, make life easier for replenishing your own minefields, and thwart enemy minesweeping efforts (“Didn’t we sweep that area?”). Minefields required constant renewal to replace these mines with new ones. Those that survived the war were largely swept afterward, as you knew the areas where you laid the mines and didn’t want your own ships hitting them. For this purpose the major navies has thousands of minesweepers, some purpose built but many converted trawlers, just for this task. Well, technically they were built/converted before or during the war for this role, but their job didn’t end when the enemy surrendered. \n\nA few weeks ago I was perusing [this US report on the beginnings of the occupation of Japan](_URL_0_) (which has many fascinating details and anecdotes) that discusses the sweeping operations off Japan. The relevant section alone is a good summary answer:\n\n > Although minesweepers are usually the first vessels to operate at the scene of impending landings, their mopping-up work continues long after the other major naval forces have completed their missions, with the result that the reports of major task organization commanders frequently contain only sketchy coverage of the preliminary minesweeping. The minesweeping operations in connection with the Allied occupation of Japan were no exception to this rule.\n\nSome 510 US ships were involved along with about 100 Japanese minesweepers. However, pressure-sensitive mines required special “Guinea Pig” ships with skeleton crews working in mattress-lined rooms with helmets and life jackets. Two Japanese destroyers were lost in this role, though to date I’ve only found the name of one, [*Kuri*](_URL_2_). A US minesweeper, *Minivet*, sank while supervising Japanese efforts (12 killed, 19 missing, 5 wounded), while another 18 ships were lost in two typhoons. However, by the middle of December some 84,000 square miles had been swept, and many other areas were waiting for the timers to run out before sweeping operations began (February 1946). \n\nHowever, some mines still dot the seabed, though as with the explosives in thousands of wrecks are effectively harmless if undisturbed. So if you happen to find one while fishing or diving, don’t go anywhere near it. Alert the local authorities and they’ll send an EOD team in to take care of it. Good training for your military. "
]
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"http://www.dtic.mil/docs/citations/ADA438971",
"http://www.laffey.org/2009_dry_dock_photo_page_courtes.htm",
"http://www.combinedfleet.com/Kuri_t.htm"
]
] |
|
mw50k | Would spherical wheels (on cars, trucks etc.) provide any benefits? If yes, are they even close to feasible? | I've seen concept cars with spherical wheels and I have always been curious to find out if they would be better than what we have? And how would we make them work? | askscience | http://www.reddit.com/r/askscience/comments/mw50k/would_spherical_wheels_on_cars_trucks_etc_provide/ | {
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"There was a time when cars had \"balloon\" tires with weak sidewalls and with the tires much higher in diameter than the rims. The problem was that the tires lacked stability on cornering. Modern tires have stronger sidewalls and lower profiles, which strengthens them for cornering. Spherical tires would have the same technical problems to work out.",
"Motorcycle tires have a much rounder cross section than automobile tires, since bikes turn be leaning over, not by turning the front wheel as in a car, with more flat-bottom tires. For a tire designed to stay flat, not lean into a turn, you want more surface area in contact with the road to deliver power from the engine. ",
"A sphere will have a smaller contact patch which reduces grip and is not ideal for safety and performance reasons. A sphere might also have more mass which also adversely affects performance. On top of that you've got either an axle which prevents any funky directional movement anyway, or a complicated (heavy and inefficient) system of above wheel rollers. So in a nutshell no, I don't think it's a good idea and I don't think anybody is actively working on this.\n\nThe next wheel advances will be in the form of in-hub electric motors and integrated suspension with energy recapture, better materials in both the tires itself and the aforementioned systems. And more environmentally friendly materials.\n\nWith that out of the way I'd like to have some fun thinking about the _very_ far future; I can see a time when our [new understanding](_URL_0_) of the [Van de Walls](_URL_1_) force gives us tires that grip at the molecular level massively improving cornering and braking, in fact perhaps even to a point beyond human tolerances.",
"There was a time when cars had \"balloon\" tires with weak sidewalls and with the tires much higher in diameter than the rims. The problem was that the tires lacked stability on cornering. Modern tires have stronger sidewalls and lower profiles, which strengthens them for cornering. Spherical tires would have the same technical problems to work out.",
"Motorcycle tires have a much rounder cross section than automobile tires, since bikes turn be leaning over, not by turning the front wheel as in a car, with more flat-bottom tires. For a tire designed to stay flat, not lean into a turn, you want more surface area in contact with the road to deliver power from the engine. ",
"A sphere will have a smaller contact patch which reduces grip and is not ideal for safety and performance reasons. A sphere might also have more mass which also adversely affects performance. On top of that you've got either an axle which prevents any funky directional movement anyway, or a complicated (heavy and inefficient) system of above wheel rollers. So in a nutshell no, I don't think it's a good idea and I don't think anybody is actively working on this.\n\nThe next wheel advances will be in the form of in-hub electric motors and integrated suspension with energy recapture, better materials in both the tires itself and the aforementioned systems. And more environmentally friendly materials.\n\nWith that out of the way I'd like to have some fun thinking about the _very_ far future; I can see a time when our [new understanding](_URL_0_) of the [Van de Walls](_URL_1_) force gives us tires that grip at the molecular level massively improving cornering and braking, in fact perhaps even to a point beyond human tolerances."
]
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[],
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"http://arstechnica.com/science/news/2008/09/paging-spiderman-new-material-mimics-gecko-feet.ars",
"http://en.wikipedia.org/wiki/Van_der_Waals_force"
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8qvwuf | When Battlefield V revealed women as playable characters, some people reacted negatively. They say women did not fight on the front lines in World War II, and that the game is "historically inaccurate" and "disrespectful". How often did women ACTUALLY fight on the front lines in World War II? | [deleted] | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/8qvwuf/when_battlefield_v_revealed_women_as_playable/ | {
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"[I have previously written on the case of Battlefield V and the case of British women in this post. ](_URL_0_) If you have any further questions about this, the reception of Battlefield V, or the case of \"historical accuracy\", feel free to ask.",
"More can be written, but to start, you might like to see this discussion: [\"How many female soldiers saw combat in WW2?\"](_URL_0_) . /u/fell-like-rain had a direct answer. /u/Searocksandtrees and Georgy_K_Zhukov linked to previous discussions by /u/Bernardito (the British case that they already pointed to), /u/Georgy_K_Zhukov (including about video games and a Battlefield game specifically), and armdoc.\n\nThis is not to discourage discussion. Further questions, data, and debate are welcome.\n"
]
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"https://old.reddit.com/r/AskHistorians/comments/8lmzi9/in_the_new_battlefield_v_trailer_a_women_is_seen/"
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"https://www.reddit.com/r/AskHistorians/comments/8lxrl3/how_many_female_soldiers_saw_combat_in_ww2/"
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|
3v7mbr | What causes these vertical lines that sometimes come stretching out of the top of a flame? | [Picture \(imgur direct link\) for reference.](_URL_0_)
I've seen this before and always found it strange. I took a picture in part to rule out it being something to do with my eyes/brain. A few minutes of googling didn't get me any information at all. The lines don't always appear, don't always appear in the same size/place/configuration and more often than not seem to disappear over time.
I can't imagine what it could be - difference in local atmospheric pressures or oxygen ratios don't seem like they could explain straight vertical lines.
Thanks in advance both to mods & commenters. | askscience | https://www.reddit.com/r/askscience/comments/3v7mbr/what_causes_these_vertical_lines_that_sometimes/ | {
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"Just guessing, but I think those are jets of liquid gas from the lighter. There's probably a burr or something on the edge of the gas nozzle. Normally the nozzle will diffuse the gas and mix it with air slowing it so it combusts gently. \n\nThere are several ways to have gas mix to make a flame. It can suck in air mixing before it is ignited. That creates the loud sorta jet flames. It can be slowed and meet the flame front- that's normal for a lighter. Some of the liquid gas can also jet through. That's what your flame looks like. If the same thing happens when you invert it or turn it to the side its likely a jet.",
"Let's talk about what the different colors in a flame represent. Most of what you are seeing is hot soot (large carbon molecules) that glows with yellow-red blackbody radiation. There is also some blue light at the bottom caused by chemiluminescence. Instead of a broad blackbody spectrum it produces narrow emission peaks. You can see [that there are continuous and narrow features in the spectrum here](_URL_1_) and I found [this figure](_URL_0_) from a [paper on soot formation](_URL_3_) showing the soot particles forming as you go up the flame. You get more soot formation when [oxygen doesn't mix well with the fuel](_URL_2_).\n\nOk, so with that introduction aside, you are seeing some soot particles get dragged up faster than their neighbors so they keep glowing at high temperature before cooling off. I basically agree with u/bloonail you are seeing some sort of jet of gaseous or liquid butane spitting out straight up from the nozzle. Maybe the nozzle is constricted, like when you cover your hose with your finger and narrow streams shoot out. I'm not convinced it has to be a liquid fuel jet rather than a fast gas jet coming from the nozzle. But I'm not sure, since fluid dynamics aren't easy to predict. After you try tipping the flame around and looking at the pattern, you might want to try cleaning the area near the nozzle and seeing if the shape changes.",
"Almost certainly an irregularity in the jet the gas emerges from. It may be scored or bent in such a way that the gas emerges with higher or lower pressure in specific locations.\n\nImagine if you had a pipe shooting out water. Score the inside of the pipe at the exit, along its axis. You will get an irregularity in the flow at that particular point.\n\nThat's what I think is happening here - a score, dent or some other irregularity on the inside edge of the outlet jet is causing this.",
"Well, the line itself is bright because flames are lit up by a suspended cloud of incandescent carbon particles. The yellow-white part is incomplete combustion. If it doesn't produce smoke, then the combustion does finish by the top of the flame, and by the top of the jet/line/thingie.\n\nSo, the question is, why is combustion delayed in one small part of the flame, so that the incandescent hot part extends higher? Speculation: too much fuel in that thin stripe, or too little oxygen, or slightly cooler gas was coming up from below, but only at the bottom of that thin section. The flame is laminar, where upstream patterns will paint themselves throughout the entire downstream flow. So, any tiny burr or chunk of contaminant on the butane orifice may be the cause.\n\nOr this: look closely, and see if there are two lines. One for each of the pair of wide metal wheels. If the striker-wheel invades the flame at all, it should produce two slightly-colder stripes, and delayed combustion leading to extended lines. Try this: tilt the whole lighter so the flame doesn't touch the two wheels. Do the lines then disappear? Then tilt it opposite. Do the lines get longer and longer as the metal wheels push into the flame?\n",
"If you look closely, it seems you can make out the beginnings of those lines in the blue part of the flame. I am leaning towards agreeing with /u/wbeaty, where the metal wheel of the lighter is causing some localised cooling or diversion of the gas."
]
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"http://i.imgur.com/kozfar6.jpg"
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"http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/Articleimage/2014/CP/c4cp03330b/c4cp03330b-f1_hi-res.gif",
"http://www.chem.unifr.ch/ma/dir_allan/candle.html",
"https://upload.wikimedia.org/wikipedia/commons/0/08/Bunsen_burner_flame_types.jpg",
"http://pubs.rsc.org/en/content/articlelanding/2014/cp/c4cp03330b#!divAbstract"
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|
3m9k84 | i want to know basic electrical terms and how they mesh together. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3m9k84/eli5_i_want_to_know_basic_electrical_terms_and/ | {
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"I'll try? There are a lot though, and I'll probably miss some.\n\nVoltage- Think of there being a \"slope\" between any two points of an electric field. The Voltage is the steepness of that slope\n\nCurrent- The rate that charge flows between two points\n\nResistance- A measure of how well a thing reduces the current\n\nPower- How much energy a circuit consumes\n\nCharge- What makes the electric field. \n\nThat's all off the top of my head, plus a few less basic ones like Flux. I can elaborate if you'd like."
]
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[]
] |
||
atyjdz | why do some songs sound familiar, despite never having heard them before? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/atyjdz/eli5_why_do_some_songs_sound_familiar_despite/ | {
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"a lot of song that get attention have similar progressions; and some times are in similar keys. \n\nChord Progressions are what order the sounds are played. for example **I–V–vi–IV** is the most common chord progression. you can check out axis of awesome's 4 chord song here. [_URL_0_](_URL_0_) \nit's pretty neat what they did. \n\nSimply put, A Music Key is basically a diagram of which notes can be played in a song. "
]
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"https://www.youtube.com/watch?v=oOlDewpCfZQ"
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||
eat5uw | Are there regions of space with many stars very close together? | Specifically I'm wondering if there are areas with hundreds of star systems within a few lights years of each other. | askscience | https://www.reddit.com/r/askscience/comments/eat5uw/are_there_regions_of_space_with_many_stars_very/ | {
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"Darn. See. I'm now to reddit and I don't know how to post an image, or I would make one with a scale bar so you could see how dense globular clusters are. Do a google image search for \"globular cluster.\" Typical scale is 100 light years diameter but this varies greatly, and stars are often within a light year separation. Look up \"Messier 15\" on google. Tens of thousands of stars within 100 light years; and a dense core where the separation could be less than 1/100 light year.",
"Oh yes, definitely. The first such area that comes to mind is a Globular Cluster. These are dense spheres of stars floating around the outside regions of galaxies. The center of these can be very packed with stars, hundreds of times more dense than our local region of the galaxy. Another potential area of dense stars is the supermassive black hole that is at the center of many galaxies. Dozens of stars orbit our own Sagittarius A* black hole within just one light year."
]
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9iz8ei | When you eat something and get hives, what causes the hives to appear everywhere (even your legs)? | [deleted] | askscience | https://www.reddit.com/r/askscience/comments/9iz8ei/when_you_eat_something_and_get_hives_what_causes/ | {
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"Urticaria (hives) are an inflammatory reaction in the skin due to the release of (primarily) histamine by a type of cells called mast cells. The histamine causes leakage of capillaries resulting in edema (swelling).\n\nWhen this is from an allergic etiology, histamine and other proinflammitory substances are released in response to an allergen/antibody (IgE) complex binding to mast cell receptors. \n\nIn the case you're mentioning a **generalized** urticarial response happens because the allergen (whatever it is in the food that you're allergic to) is disseminated throughout the body in the bloodstream after digestion so it's possible for many mast cells and antibody/allergen complexes -- from head to toe -- to meet up and cause this inflammatory response. "
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|
ela0hx | why people curse when they’re angry or frustrated ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ela0hx/eli5_why_people_curse_when_theyre_angry_or/ | {
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"so humans like many animals are vocal and social creatures, we have emotions and we express them. expressing yourself at times may be difficult. consider three year olds throwing tantrums, they feel many emotions very strongly but they don't know what they are/what they mean, and they do not know how to express them properly. this is wear swearing comes into play. one of the main reasons people swear in anger or frustration is a means of expressing themselves. say you drop your keys in a puddle, if you just go \"oops\" it means it wasn't a big deal, but if your key fob got ruined you yell a curse expressing that what just happened is more serious and has caused you more duress.\n\nso you commonly see the old wives tale that people swear because they lack vocabulary, when in fact many psychologists believe it to be the opposite, people swear as more open expression. this happens in all cases, pain, empathy, etc, swearing helps us communicate what we are feeling."
]
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||
2s4y2n | What IS a gravitational singularity at the center of a black hole? | I'm trying to understand the concepts behind a black hole but the vocabulary is beyond my grasp. Conceptually, I get the gist of an event horizon, [gravitational time dilation](_URL_0_), and [spaghettification](_URL_1_), but what *is* at the center of the black hole (singularity)?
Is it impossibly crushed matter of everything the black hole has eaten? Or is it just a single point, because everything that is eaten is destroyed? Is it an actual "thing"? Is it one size in all black holes, or does it vary?
This stuff is fascinating to me but I just can't wrap my mind around it all. | askscience | http://www.reddit.com/r/askscience/comments/2s4y2n/what_is_a_gravitational_singularity_at_the_center/ | {
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"General relativity predicts that for large enough objects with the right initial conditions the collapse of that object into a black hole, which has an event horizon. The collapse continues, according to general relativity, till there is a point of infinite mass density at the center of the black hole.\n\nHowever, there is no reason to believe this singularity is physical. Once you get down to a distance of about 10^(-35) meters, general relativity as it stands cannot be sufficient; we need a theory that incorporates general relativity and quantum field theory. We don't have such a theory as of yet, but when we do, it will tell us the right way to describe physics at ultra short distances. This won't be plain old ordinary general relativity, and so there is no reason to think the singularity predicted by general relativity is what the correct quantum theory of gravity will predict.",
"The singularity is a limit that you run into when modelling black holes with general relativity.\n\nGeneral relativity is incompatible with quantum field theory. Once we are in the realm of a singularity, we're in the area where we don't have a model of physics that is consistent.\n\nWhich is a long way of saying \"Dunno.\"\n\nWe can be fairly sure you don't actually get a single point of infinite density, as that is not permitted by QFT.",
"I always like to think of it as an asymptote in the fabric of spacetime. There's an imaginary point at the center that the surrounding space and time get incrementally closer to without ever actually touching. Imagine the classic \"ball in the sheet\" example that is used to help visualize the effects of gravity; as the mass of the object increases, the depression in the sheet becomes deeper and deeper. At some point there would be a sort of \"critical mass\" where the object sort of rips through the sheet, and the depth of the depression becomes infinite.",
"We really don't know. We know that the gravitational force at the center is incredibly strong, but we don't really know what happens to stuff that goes in, under the incredible stresses we know are present, it is hard to say what happens, and because nothing can get out except for Hawking radiation, we don't have much information. We can measure the mass and a few other things, but that doesn't answer your question.\n\nOur current models might have a prediction about what is going on, but without a method for testing them, we don't really know.",
"I have a related question. How does the singularity form in the first place? I thought that it would require infinite energy to accelerate a mass to c. Why isn't a black hole more like a \"nearly black\" hole, requiring an escape velocity asymptotically approaching c, but never reaching actual c? Does that make sense?",
"I remember being shown a diagram in high school of a visualized space time grid, and when you would drop a planetary mass on the grid it would form a divot relative to its mass and density in this space time grid. When you would drop a smaller mass like a moon right on the edge of this divot it would orbit the planet but, when they would drop a mass with the density of a black hole onto this grid it would look like it was falling right through this grid of space time [visualized here.](_URL_0_) So wouldn't a singularity be something so small but dense enough to rip through the fabric of space time? Also if it is essentially ripping through the fabric of space time, can this rip possibly lead to another dimension? Im not referring to worm hole theory either where you go in one end from a in the universe and end up at b on the other side of the universe.",
"I kind of wonder: if some unknown force prevents the centre of a black hole to crush itself into a true singularity, but instead forms into a ball of superdense matter that is smaller than the size of the surrounding black hole, could we ever figure it out in any way by outside observations?",
"A theoretical point at which gravity is infinite. If you solve Einstein's field equations for a source where the escape velocity is so high even light can't escape it, then you get a solution which indicates that there is a point of infinite gravity and density, with no volume. ",
"Can some help me understand how time can pass at different times at different levels of gravity. I understand it happens, but I can't grasp the idea that time is actually a physical thing that can be affected. Is that the right way to think about it? ",
"Generally it is not a good idea to expand the known laws of physics far beyond the circumstances in which they are proven. In the past there was always some new physics at high speed, small size, high energy, high gravity and so on. We simply won't ever know what is inside a black hole because nothing can come out of it that we can measure.",
"If we were to take the term singularity seriously, it would mean that space and time *as we know it* stops to exist there.\n\nHowever, it is very likely that applying pure general relativity to a system of a scale that small (atomic scale) is not leading to a physical result and we have to find a bigger theory that describes both phenomena from quantum physics and relativity.",
"read up about the notion of a [Schwarzschild radius](_URL_0_)\n\nit has helped me to understand black holes better.\n\nright now, we don't know much about what happens at the center of the singularity because we can't look into it. and by look into it, i mean measure it, and that's due to the schwarzschild radious.\n\nthe singularity at the center of a black hole is basically the mass at the center, which can't reach escape velocity for us to view it. so basically, for now, we can't say if it's crushed or not, destroyed or not (although matter is never destroyed, but then again according to some recent theories, it can be destroyed in universes with black holes.. but lets keep things simple).\n\nit's a matter of time (hah!) till we figure it out, we just need the tools and the theoretical physics/math. most modern (definitely all classical) physics isn't enough to explain the theoretical math that tries to describe black holes, at the moment.",
"I always thought of it as an mathematically described asymptote that rips through space time due to the initial collapse of the star. \n\nOf course the real answer is we don't know, and as of right now we don't have the math. (Physicists don't like asymptotes in their data when they want to know what that asymptote is.)\n\n",
"Singularity - At this exact point, we don't know what's going on.\n\nIf anyone can figure that out with sufficient evidence, I imagine it's worth a Nobel Prize. The discoverer might even unlock the secrets of the Universe.",
"No one knows what exists beyond the event horizon. It can best be described as a permanent pause button on the last 10 minutes of a white knuckled gripping the edge of your seat non stop roller coaster ride of the most incredible movie you'll ever see. The best explanation I've ever seen or read that describes it can be found in the movie Interstellar. To go further Einsteins blackhole math that many call broken because the final answer always comes out to \" infinity \" may actually be correct and only assumed to be broken because scientists and mathematicians are limiting the definition of infinity to only encompass one thing.",
"The way I envision it is that the singularity is the point where spacetime has twisted upon itself so fully as to reduce the volume in the center to zero. As the black hole ceases to consume matter, the twisting slows as the black hole emits Hawking radiation. Eventually, the black hole's twisting decreases with further radiation, leading to the eventual demise of the black hole. In this manner, there's no \"naked singularity\".",
"Does not Time slow down as one approaches the singularity? If is it possible that the singularity actually does not exist yet, as there has not yet been enough time since the creation of the universe for the matter to completely fall all the way in?\n"
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a0hgpk | Why wasn't china a more active belligerent in ww2? Considering the "incidents" that started in 1931 between them, Japan and Manchuria... | [deleted] | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/a0hgpk/why_wasnt_china_a_more_active_belligerent_in_ww2/ | {
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"I'm no expert, but my understanding was that China was pretty disorganized and very ill equipped. China wasn't a nation so much as a fractured land ruled by local warlords following the fall of the Qing dynasty and the civil war between Communists and nationalists. Hopefully that at least partially answers your question until someone more knowledgeable can answer.",
"China was actually very active in the Second World War. They don't often get a lot of credit due to the fact that they were absent on the European front, but they absolutely played an integral role in the Pacific. \n\nFor one, when China was invaded in 1937, it's country was in complete shambles. The invasion happened at the time of a civil war between the Nationalists and the Communists, and China was anything but united. The Communists and the Nationalists attempted to begin an alliance to fight against Japan, but had so many ideological differences between one another that a united coalition force never worked out. As a result, most of the fighting against the Japanese was done by the Nationalists (most not all). In addition, the Nationalists did not have complete control over their portion of China, but was rather a loose string of alliances between several different warlords, many of whom had their own ideas and agendas. Japan had long desired China's rich resources, and found the perfect moment to invade a weak and divided China. \n\nEstimates of Chinese killed during the conflict with Japan (1937-1945) range from a staggering 10-20 million. The divided Chinese fought resiliently, but were outmatched by superior technology, weapons, and leadership. However, the Chinese did succeed in getting a handful of important victories against Japan despite massive casualties. U.S. pilots that were often forced to crash land in China were rescued by Chinese citizens who were more than willing to assist them. It is because of this that many American pilots were able to walk away alive, and in many cases, continue to fight in the war. (See Doolittle Raiders)\n\nBecause of the conflict in China, Japan was unable to commit all of it's forces to fighting the United States and the British in the Pacific. They were forced to keep a decent number of their forces in China due to their refusal to surrender. In my opinion, the efforts in China played a integral role in dividing the Japanese forces, helping the United States and Britain to make the advancements in the Pacific that they did. Had the Chinese surrendered in 1937/38, Japan's forces could have easily turned towards the USSR, British India, or even the United States. "
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3eqlsx | if you had a stick one lightyear long, would the kinetic energy transfer faster than the speed of light if you poked something? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3eqlsx/eli5_if_you_had_a_stick_one_lightyear_long_would/ | {
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"No. The stick would not move all at once; your push would propagate down the stick at the speed of sound in whatever the stick is made out of. "
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25hx89 | why do girls and women tend to view more things as "cute" than boys or men? | I speculate that it might be society's norms that's shaping women to be more like this but I really don't know. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/25hx89/eli5why_do_girls_and_women_tend_to_view_more/ | {
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"heternormativity. ie: that's how we customarily act according to gender roles.",
"I'm no expert, but I believe that since women were 'built' to nurture and feed babies, they have a larger biochemical response to 'cuteness' (which, if you don't know, is a response to recognize our own young, e.g. large head-to-body ratio, large eyes etc.) Their brains are more tuned to pay attention to, and look out for 'cute' things. It's an evolutionary thing.",
"Because (as you mentioned about society's norms) girls are taught things are \"cute\" while boys are taught things are \"cool\" and we repeat this through life.",
"_URL_0_\nThis is a great video! Basically we think things are cute when they remind us of children/younglings. Females are maternal and will feel more strongly towards these \"cute\" things. ",
"Well there are different angles that you can look at it from:\n\n- Mothers naturally evolved the ability to respond to 'cuteness' as it represented offspring. Mothers who considered their babies cute were more likely to protect offspring till adulthood thus passing on their \"cute feeling\" genes.\n\n- Offspring that were more \"cute\" were more likely to be protected and more likely to survive, thus either creating or reinforcing the \"cute\" reaction.\n\n- Society gender norms generally seem to evolve from biological differences so girls technically find children cuter - but the extension to other domains which can be considered cute is probably a society thing, e.g. Hello Kitty or something like that."
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2zhakb | Is the exact location of Carthage known? Are the ruins in the area Phoenician or Roman? | After being corrected on this point in a recent thread, I became curious. I had always heard that Carthage was so utterly destroyed that we can not be sure of its exact location. However a quick google turned up plenty of results for Carthaginian ruins. What's the situation here? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2zhakb/is_the_exact_location_of_carthage_known_are_the/ | {
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"[We totally know where Carthage was](_URL_0_), and [a friend of mine](_URL_1_) wrote her dissertation on the Roman reconstruction under Augustus. The \"salting the earth\" thing was elaboration."
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8eckcu | Were there ever any significant emigrations by Jewish peoples during the colonial period to escape religious persecution? | The most famous story of North American colonialism is obviously the Mayflower Pilgrims, who emigrated to America in order to avoid loss of religious/cultural identity. This seems like a problem which European Jews would likely commiserate with during the period of American colonialism. Were there any Jewish Mayflowers? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/8eckcu/were_there_ever_any_significant_emigrations_by/ | {
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"I think that the best example of this in the colonial period is the Marranos who left Spanish-controlled lands in order to return to Judaism. In 1391 was the first massive wave of coerced conversion of Spanish Jews, and in 1483 the Spanish instituted the Inquisition in order to police these New Christians. By 1492 the Inquisition had successfully convinced Ferdinand and Isabella to kick all practicing (non-converted) Jews out of Spain. In a sense, that could count as an emigration to escape religious persecution- Jews generally went west to Portugal, south to North Africa, and east to the Ottoman Empire. In 1497, the king of Portugal forcibly converted all Jews in the country, and by 1536 the Inquisition established itself there as well. Spain and Portugal (soon to become one country under the Iberian Union). Thousands of New Christians remained on the Iberian Peninsula. \nMany of these New Christians were completely Christian as far as their religious theology and conduct. However, due to the Spanish policy of limpieza de sangre (blood purity), these New Christians were limited by their Jewish ancestry in terms of their social status and ability to socially climb. This was the first time that converts were given a racial distinction. Previously, once a Jew converted (and the Church worked HARD to get Jews to convert), s/he was as Christian as any other. Now, there was a social barrier created by one's ancestry. People had to have family pedigrees in order to prove that they were Old Christian- of course, forgeries abounded which masked New Christian ancestry. \nOf course, right around the same time as the Expulsion was Columbus's expedition to the New World (in fact they were within a few days of each other), and the New World ended up providing not only a source of wealth but a way for many to start anew. Many of these New Christians who were Christian at heart but resented being judged by their or their ancestors' former Judaism often traveled to the New World, where they could make new names for themselves and improve their situations. \nWith those New Christians, often called Marranos, who continued to secretly observe Jewish practice, many of them traveled throughout the world, including to the communities of the Spanish-Jewish post-expulsion diaspora, in order to return to Judaism in the several hundred years after the expulsion. By the 1600s, this had expanded past the areas mentioned above and a very large community had been established in Amsterdam, which became renowned as a center of Sefardic Jewish life and trade. However, many also traveled to the New World, where, conveniently, an Inquisition was not yet established (it wouldn't be until 1571) and it was easier to stay under the radar. Even after the Inquisition was established, there were still clandestine communities of Marranos who observed Judaism- the most famous is probably the family of Luis de Carvajal el mozo/Joseph Lumbroso, whose story is absolutely fascinating. \nAlmost all of Central and South America were controlled by the Spanish/Portuguese and ended up with an Inquisition at some point, but in 1631 Recife/Pernambuco, an area on the coast of Brazil, was captured by the Dutch and soon became known as a haven for Jews, whose population at some points purportedly was twice that of the Christians. Many Marranos either lived as Marranos in peace there or returned to normative Judaism. However, Recife was recaptured by the Portuguese in 1648 and that period of Jewish utopia ended. Jews also settled in areas like Suriname (which had a city called Jodensavanne, or Jewish savannah) and Jamaica, which were controlled by the British, and Curacao and Sint Maarten under Dutch control. Of course, in 1654 when the Dutch took control of New York, Spanish Jews (some of whom were escapees from Recife) became some of its first settlers. "
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3et36s | how do reptile ears work? | I just got a bearded dragon and I was wondering how his ears work, what keeps bugs out of his ears? And does the skin linin the inside of his "ear holes" shed? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3et36s/eli5_how_do_reptile_ears_work/ | {
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"Their ears work like yours. There is a very thin and delicate membrane at the base of the ear canal. DO NOT TOUCH it, or you may damage your pet's hearing. The skin lining the exterior ear canal can shed, usually in little flakes. You don't need to pull them, when they are done they will come off. Ears can become infected, and this is a serious problem for a breaded dragon. If the membrane seems like there is a yellow blob behind it, you need to go to the reptile vet."
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fr4jxy | British museums | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/fr4jxy/british_museums/ | {
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"Apologies, but we have had to remove your submission. We ask that questions in this subreddit be limited to those asking about history, or for historical answers. This is not a judgement of your question, but to receive the answer you are looking for, it would be better suited to /r/MuseumPros.\n\nIf you are interested in an historical answer, however, you are welcome to rework your question to fit the theme of this subreddit and resubmit it."
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456eto | why are the planet orbital patterns in a flat ring | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/456eto/eli5why_are_the_planet_orbital_patterns_in_a_flat/ | {
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"Asked and answered, plenty of times. It comes from everything spinning around it and settling into what are now the planets."
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4qsyju | when you're dehydrated, is it better to chug water fast or to drink it slowly over time, or does it even matter? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4qsyju/eli5_when_youre_dehydrated_is_it_better_to_chug/ | {
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"I've heard on a survival show that your body can only absorb like 1 liter of water per hour, so I don't think the pace at which you drink it really matters. If you drink more than 1 liter of water in an hour your body will just pee it out.",
"Depends on how badly you're dehydrated. If severely, like to the point of passing out, drinking is an option only if no medical facility is available. Otherwise, what you want are immediate IV saline fluids on a controlled drip rate.\n\nIf you're moderately to seriously dehydrated, you should shoot for about liter of fluid intake per hour. Not because your body can't absorb more, but because you can actually risk cerebral edema (fluid swelling of the brain) and heart arrhythmia by rehydrating too quickly. Your blood is slightly salty. When you're dehydrated your blood gets saltier (called hypertonicity or hypernatremia), and that pulls water out of your cells including your brain. It's why you get stupid when you're overheated and dried out, and why your heart rate shoots up. Your blood volume and pressure drops, which is why you get headachy. Chug a ton of water, and it gets rapidly absorbed into your blood stream. Your blood salinity drops (hypotonicity), your blood volume shoots back up, and the balance of potassium and sodium in your body gets thrown out of whack which can mess with your heart's internal pacemaker or cause bradycardia - a sudden drop in heart rate. In addition your dried out brain cells which have tried to adjust to the lack of water start sucking in all of that new H2O in your blood and can literally swell to the point of bursting. I've seen people have seizures because of too-rapid hydration after getting dehydrated.\n\nIn hot weather, drink constantly. Minimally a liter of liquid per hour of exposure, double that under exertion. If you're thirsty, you're already behind the curve. If you're feeling weak, confused, or headachy, get out of the sun and to the coolest spot you can, wet down your body if possible, and drink at a moderate pace."
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ara9ox | how does asymmetric encryption work? | Taking A-Level Computer Science, and I'm very comfortable with the majority of concepts that I study.
I've never really understood asymmetric encryption though - outside of my studies, having read about public/private key encryption and SSL, understanding how the communication works at a basic level, the only thing that really throws me is how you can encrypt something and not be able to reverse it.
Are there any explanations or examples?
Thanks! | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ara9ox/eli5_how_does_asymmetric_encryption_work/ | {
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"The trick is to find problems that are easy to calculate in one direction, but difficult to reverse. Then you base your algorithm on that kind of problem. \n \nFor example, plain multiplication does NOT have that property. Division is pretty much just as easy to perform as multiplication, so those two things are not suitable for asymmetric encryption. If I tell you that I multiplied 12 by some number and got 120, it's trivially easy for you to reverse that and figure out that the number I used was 10. \n \nBut there are some problems that are not easy to reverse like that. Factoring large prime number products is one of them. If I tell you that I multiplied two large primes and got 56713727820156410577229101238628035244, it wouldn't be simple for you to figure out what those prime factors were. With a computer you could eventually do it, of course. \n \nBut if I make my primes REALLY damn big so that the resulting product is REALLY REALLY damn big, your computer program will probably take a long, long time to factor it. Like centuries, or millennia. And that's good enough to use it for encryption. \n \nFactoring the products of large primes is not the only problem that is hard to reverse like that, but it's the one that is probably used the most and is easy to understand. "
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1ax6mq | Why is the direction of magnetism of current determined with a cross product? | How does the Biot Savart law work? What causes magnetism to work perpendicular to current? | askscience | http://www.reddit.com/r/askscience/comments/1ax6mq/why_is_the_direction_of_magnetism_of_current/ | {
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"A magnetic field is not really a vector, like the electric field, it's really a bivector, pseudo-vector, or 2-form. As a vector has a direction, a 2-form lives in a plane. The thing is, in 3 dimensions, there are exactly as many dimensions (x, y, z) as there are planes (x-y, y-z, z-x). When we say a magnetic field is pointing in the z-direction, it's actually a bivector in the x-y plane. You can get the direction of a vector associated to a bivector by taking the vector product of 2 vectors in the associated plane.\n\nSo essentially, the cross product appears as an artifact of us pretending that the magnetic field is a vector instead of a bi-vector.\n\nIn d space dimensions, while an electric field would always have d components, a magnetic field would have d(d-1)/2, so in general we couldn't talk about the \"direction\" of a magnetic field."
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1qp30q | My best friend and I have decided to read the Federalist Papers together. What things should we keep in mind while reading them? | Things such as the cultural context. We know they were being written to to the New Yorkers deciding whether or not to ratify the constitution; but what was the mindset of the average New Yorker given the responsibility of voting? What was the mindset of the authors? Things like that. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1qp30q/my_best_friend_and_i_have_decided_to_read_the/ | {
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"_URL_0_\n\nIf I could suggest it, I'd take a quick backstep before you dive into the Federalist Papers and check out the first two or three chapters of \"Radicalism of the American Revolution\" by Gordon Wood. I don't think we have a full grasp of how stratified the society was and how engrained the concept of patriarchy was. If you're trying to get at the cultural context, Wood explained how alien this society was to the one that we've become familiar with in the 20th century.\n\nThis is Hamilton who believed (really!) in the \"unthinking populace\" and a more virtuous aristocracy.",
"Keep in mind the problems that the new United States was facing at the time between the Treaty of Paris in 1783 and the eventual ratification of the Constitution in 1789. Here are some of those problems, in a nut shell:\n\n The Articles of Confederation made the central government extremely weak. It had no power to tax or even to require states to pay their share of the Confederation's budget. Debts kept piling up as different states either paid far less of their share of the Confederation's debts or ignored the bills altogether. This spiral of debt and non-repayment, coupled with the massive crushing debt incurred during the Revolutionary war, cause the American dollar - called the \"Continental\" - to become worthless (especially since specie - or physical money, usually made of silver - was increasingly hard to find forcing the government to print paper money; this led to the phrase \"as worthless as a Continental.\") This led to increased interest rates on loans, which in turn harmed everyone from Merchants in ports like Boston to farmers in the western regions of the New Republic. A good example of this is Daniel Shay's Rebellion - a spontaneous uprising of disaffected farmers who prevented (sometimes violently) the operation of civil courts, thus stopping the foreclosures of family farms. Shay and his neighbors were being crushed by the relatively high taxes imposed by the State of Massachusetts, the increasingly high interest rates on their loans, and the lack of hard currency so they took up arms. This rebellion certainly played a role in the formation of the Philadelphia Convention's ideas on economic policies of the proposed \"Federal\" government while they were drafting the new constitution.\n\nWorse, there was no true executive branch - sure, there was a \"President of the Congress\" but as Alan Brinkley points out in his textbook *Unfinished Nation*, the position became largely symbolic with the President acting as little more than a secretary who recorded, cataloged, and disseminated the edicts of the ineffectual Congress. Congress had little ability to force states to acquiesce to the demands of the Confederation (or even compel state representatives to show up for their jobs), so in essence, the body was impotent.\n\nOn top of that, there was no judiciary branch to hear cases regarding the constitutionality of Congressional laws nor to resolve disputes between states. This was predicated on the idea of \"States Rights\" i.e. that states, as sovereign members of a loose association, were the ultimate authorities in the land and the Confederation's government had no authority to impose its will. This *may* seem like an ideal situation to the hyper-sensitive political ideologues of the early American republic - a weak central government ensures that no one despot would arise to rule with absolute authority AND that a Parliament dissociated from the everyday concerns of the populace, would be unable to pass onerous laws similar to the Tea Act, the Coercive Acts, and the Stamp Act - but the problem with that approach was, however, there were no mechanisms to defuse disagreements between the various states. For example, the Ohio valley was coveted by Pennsylvania and Virginia; both of whom claimed their original Royal charters (or other documents) offered them said territory. Both were on the brink of going to war over the valley until the Northwest Ordinance was passed, making the region a new territory with a mechanism to become an independent state in its own right. Similar disagreements led to breakdowns in commerce as different states printed different amounts of money in different denominations; some states would not recognize the documents from others; and other disputes ranging from support of the Anglican church to the issue of slavery threatened to rip the Confederation apart.\n\n As if that wasn't bad enough, while the provisos in the Articles *did* provide a mechanism to change or alter these articles, the requirement was impossibly high: that *all* states must ratify any Amendment to the Articles. With no unifying enemy to rally against, the states acted as petty and jealously towards each other as the Princes of Renaissance Italy did; they worked hard to undercut each other at every turn; when most New England's ports closed themselves to British shipping in protest of British economic and military intimidation, price fixing, and market manipulation, Connecticut rolled out the red carpet (so to speak) to British merchants and reaped the rewards while its brothers further north fumed.\n\nHowever, that is not to say it wildly unpopular. Some Founding Fathers disagreed with the idea that there needed to be a strong central government and, indeed, looked at the troubles of the Confederacy not as problems, but the expression of true freedom and democracy. For example, during Shay's Rebellion in 1786, while George Washington wrote to David Humphreys lamenting that \"I am mortified beyond expression that in the moment of our acknowledged independence we should by our conduct verify the predictions of our transatlantic foe and render ourselves ridiculous and contemptible in the eyes of all Europe...\" (see _URL_0_ ), Thomas Jefferson gleefully quipped to James Madison that \"a little rebellion now and then is a good thing\" and \"[such rebellions were] as necessary in the political world as storms in the physical.\" (see _URL_1_ ). Interestingly, when the convention was convened, Thomas Jefferson referred to those crafting the new document as \"demigods\" of the new nation and sought to instruct them. Only after the details of the Constitution came out did he begin to really oppose it, writing under the pseudonym \"Cato\" and \"Brutus\" countering the arguments of John Jay, Alexander Hamilton, and James Madison (who wrote collectively under the pseudonym \"Publius\").\n\nOne of the main issues in the controversy over the Constitution was the very nature of its crafting; that it was done in secret and only after the document was finished was it revealed to the wider public. This led to charges that the elite statesmen who had crafted it had, instead, created a \"monster.\" The fact that the Federalist papers make a favorable case for a certain level of elitism (which you'll see in the papers) didn't really help ease people's fears about a betrayal of the egalitarian rhetoric of the American Revolution. \n\nNew York was one of the last states to ratify the Constitution and was a microcosm of the country at large; a unified but minority Federalist core against a larger but more fractured anti-Federalist majority. New York had plenty of rural land and farmers, a long history of prominence in Colonial and Early Republic politics, and was the 'canary in the coal mine' as it were - if the Federalist argument could succeed here, it stood a very good chance of being ratified throughout the country. \n\nA really good gauge of how divided the country was over this issue would be to also read some of the exchanges of insults between people like Thomas Jefferson and Alexander Hamilton during the ratification debate. \n\nI know it was a huge nut shell, but hopefully this helps you understand some of the background and context of the Federalist papers.",
"One of the more important things to understand is that both Madison and Hamilton considered the Constitution a failure. In particular Madison cited the lack of a Federal veto of the states and the states having representation within the senate. As such some of the arguments should be viewed as arguments that they thought would be effective rather than arguments they themselves believed. We also have no comprehensive voting data for any state outside of Massachusetts until the early 19th century, so attempting to analyze support and opposition to the Constitution is difficult outside of broad pictures. Know that New York was doing extremely well in the mid 1780's, it had by and large pulled itself out of the depression much of the rest of the country was in. Furthermore New York lacked the western discontent that other states had, partially because of their very sound printed currency (which traded on par with gold and silver). The New York state government also earned between 1/3 and 1/2 of its' revenue from import taxes allowing the state to keep real estate taxes low, contributing to happier westerners the new Constitution threatened their import taxes. New York had also seized a lot of land from loyalists at the end of the war and had sold most of it to tenant farmers, giving the state over three million dollars and helping to breakdown the power of New York's wealthy elite, the confederate congress had pushed for states to return loyalist property and New York feared it would have to return the funds and George Clinton in particular would lose a large portion of his voting base of middling sorts and reverse a miniature social revolution to the political elite families that dominated New York politics. Finally its important to remember that even within New York there is little evidence that the papers played a meaningful role during the debate. In fact many of the Federalists within New York noted that while the *Federalist* sat well with the elite it was poorly written to address the poorer farmers who would decide the election and the *Federalist* was not distributed in large numbers to the Anti federalists parts of the state(New York allowed all White men to vote in the election for delegates to the convention as opposed to only those with the suffrage). John Jay did write a pamphlet entitled *An Address to the People of New-York, on the Subject of the Constitution* which Federalist leaders did find effective and publish throughout the state. When all was said and done however anti federalists outnumbered federalists more then two to one at the ratification convention.\n\nJay, Madison and Hamilton are primarily addressing as their audience three demographics\n\n1- The Remaining Manor Lords- Afraid of the States laws seizing Loyalist estates and fearing the power base of George Clinton ( which tended to be more middle class and farmers)\n\n2- Tenant Farmers- Who could be coerced by the elite ( who owned the land they worked) into siding with the Federalists, although because of the recently introduced secret ballot this would prove more difficult\n\n3- Merchants, tradesmen, urban professionals- Who, like in most states, hoped the Federal government would revive the economy and foreign commerce"
]
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"http://shaysrebellion.stcc.edu/shaysapp/person.do?shortName=george_washington",
"http://shaysrebellion.stcc.edu/shaysapp/person.do?shortName=thomas_jefferson"
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3hev2r | How did Germany heal the relationships with its neighboring countries after World War II? Can we compare what Germany did with what Japan has done (or not done)? | It's the 70th anniversary of World War II, and this question came about when I started thinking about the anti-Japanese sentiment that is deeply embedded into China, Korea, and other East Asian countries, even today. Germany doesn't seem to have this problem (at least not that I know of, and at least not with America), and I would like to know how Germany took steps to heal the wounds of World War II and the Holocaust. I would also like to know how this compares to what Japan has done (or hasn't done) to mend its relationship with its neighboring countries.
| AskHistorians | http://www.reddit.com/r/AskHistorians/comments/3hev2r/how_did_germany_heal_the_relationships_with_its/ | {
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"After checking the rules, I will address Japan as best I can. Full disclosure, I live in Korea and I think the Japanese government's position on this issue is horrible, but I love spending time in Japan.\n\n[This article from Foreign Affairs](_URL_2_) pretty much answers your question. The Japanese ignore their conquests of Korea, Manchuria, and China and the enslavement, human experimentation, rape, arson, and murder that it entailed. Instead, they tell a tale of American imperialists and atomic bombs where Japan is the victim.\n\nJapan has apologized many times, but the issue is more one of sincerity.\n\nIn Korea, one of the most important apologies was the [Kono Statement](_URL_0_). On the topic of forced prostituation, euphemistically called \"comfort women\", the Chief Cabinet Secretary Yohei Kono stated that:\n\n > Undeniably, this was an act, with the involvement of the military authorities of the day, that severely injured the honor and dignity of many women. **The Government of Japan would like to take this opportunity once again to extend its sincere apologies and remorse** to all those, irrespective of place of origin, who suffered immeasurable pain and incurable physical and psychological wounds as comfort women.\n\nThe problem now is that the current Prime Minister, Shinzo Abe, likes to hint that he might \"revise\" or repeal the Kono statement, that the issue needs more study.\n\nJust last week on the 70th anniversary of the Japanese surrender, Abe gave a speech. [Here is a great analysis](_URL_1_) by a Korean lawyer on the \"dog whistle\" issue of the speech; the code words that Abe uses to sound sincere to non-Asians, to appease his base at home, yet still offend Korea and China.\n\nTLDR - Japan apologizes as infrequently as it can and it uses roundabout language in an attempt to evade taking responsibility for its actions in Asia between 1894-1945."
]
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"http://www.mofa.go.jp/policy/women/fund/state9308.html",
"http://askakorean.blogspot.com/2015/08/sorting-through-shinzo-abes-dog-whistles.html",
"https://www.foreignaffairs.com/articles/japan/2009-05-01/perils-apology"
]
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|
1li0az | If I kill an ant, will his buddies come looking for him? | askscience | http://www.reddit.com/r/askscience/comments/1li0az/if_i_kill_an_ant_will_his_buddies_come_looking/ | {
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"I remember this from [a previous thread](_URL_0_). Here's a fantastic answer from /u/TheSecretMe:\n\nAnts have extremely little direct ant to ant communication aside from checking if ants actually belong to the same colony. (which is more of a one sided check than a two sided conversation) Here's a quick and dirty explanation of how ant colonies manage to do complex decision making and logicists with very uncomplicated minds:\n\n* Ant A is a scout. Ant A leaves the nest with all the other scouts and embarks on a solo semi random search pattern.\n* Ant A finds a food source! Ant A takes a chunk of food and makes a beeline back to the nest, laying down a scent trail from the food to the colony.\n* Ant B is also a scout, during his semi random scout pattern he finds the fresh scent trail that ant A laid down. Ant B now has a decision to make. He could go and check out what ant A found, or he could continue his semi random search pattern. At the moment the trail is relatively weak, let's call it a 50/50 decision. For the sake of argument ant B goes to find the food source.\n* Ant B finds the food, takes a chunk and heads back to the colony, also laying down a scent trail. Ant B's scent trail *reinforces* the scent trail already laid down by ant A.\n* Ant C is also a scout. Ant C finds the scent trail laid down by ant A and reinforced by ant B. Ant C has to make the same decision as ant B but this time the scent trail is a little stronger and it's no longer a 50/50 decision for ant C. To stronger scent trail is more interesting and more likely to attract ant C. For the sake of argument, ant C follows the trail towards the food.\n* The food is still there! Ant A must have found something big. Ant C takes a chunk, heads back to the colony and *reinforces* the scent trail. \n* By now the scent trail has been reinforced several times by ants A, B, C and any other ants that followed the trail. In fact the trail keeps getting stronger as it's more likely to entice ants to follow it to the food and head back while *reinforcing* the trail.\n* This keeps going until the food is gone. Some ants will still find the trail, but since the food at the end of the trail is gone, none will head back to the nest while reinforcing the trail.\n* The scent trail will decay fairly quickly and eventually disappear.\n* What the ants achieved here is a complex solution to a logistical problem without any direct ant to ant communication or higher up management. Individual ants know how to lay down a trail, and know how to respond to finding a trail. But they don't have to understand management, communication or logistics. The trail system means man (ant) power will continue to be applied until no longer necesary. Large food finds will attract many ants for transport while small sources will be gone before a sufficiently strong scent trail is created to attract many ants. Thus avoiding any time wasting.\n\nThis is what is called a hive mind. A system that can reach decisions and solutions that are beyond the minds of it's individual components.\n\n**So in short no, ants will not actively go looking for missing members.** There simply aren't any ants keeping track of the big picture. It's just a lot of individual ants, doing individual jobs but working with a system that produces a fantastic group effort without them knowing it. Ants have many such behaviors that have little or no group awareness but huge coordinated efforts when performed by many ants."
]
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blmzog | why does nothing ever really happen to huge corporations who massively break the law and cause people to die? like boeing just recently? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/blmzog/eli5_why_does_nothing_ever_really_happen_to_huge/ | {
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"Corporations are financially liable. This will cost Boeing a fortune but does not appear to be a criminal issue. If a crime is uncovered, employees or officials can be charged. \n\nBasically this is a civil problem and the forthcoming investigations and litigation will be civil, not criminal."
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1juan8 | Why did the general public tie the performing arts (theater, etc.) to prostitution? | Mostly this is within a European context, but I'm also really curious about other parts of the world as well.
I know why ballerinas from France in the 1800s and why giseng in South Korea (as well as geisha in Japan) were connected to and treated like prostitutes, but I'm wondering if and why these connections were made outside of those two specific examples. Why is it that so many cultures had a tendency to connect the performing arts to prostitution? Does this stereotype exist outside of the Western world and Japan/South Korea as well? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1juan8/why_did_the_general_public_tie_the_performing/ | {
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"/u/merdre gave a detailed answer on 'the stigma of the stage' 3 months ago that I love so much I have it saved, so [here's a link](_URL_0_) to the older discussion. ",
"Dunno about anything but England.\n\nDuring the early days of commercial theatre in England, from the 1570s to the 1640s, actors were looked upon as little better than vagabonds. Commercial acting troupes had to be sponsored by a nobleman, so that actors were technically part of their household, and when traveling they would wear the livery of the sponsoring earl (who did not actually support them except when they furnished entertainment for weddings and holidays). Women were forbidden to act on stage, so their parts were played by apprentice boy actors.\n\nIn London, however, where the first permanent public theatres were built, the businessmen and city fathers hated the theatre (for moral as well as practical reasons: the plague, and the fact that plays were performed in the afternoon when everyone was supposed to be at work, especially apprentices), and in 1575 outlawed them inside the city limits. This forced the theatres to move just outside the city, where brothels and bear-baiting arenas flourished (both also outlawed inside London). \n\nSince they were in the same vicinity, prostitutes would solicit business both inside and outside of the theatres (admission to the grounds was only a penny). Some theatrical impresarios such as [Phillip Henslowe](_URL_0_) and actors such as Ned Alleyn invested in the surrounding properties, becoming landlords (along with several churchmen) of brothels and animal arenas.\n\nAfter 1642 with the ascension of the Puritans and the [interregnum](_URL_1_), theatres were closed down and public acting outlawed. After the [Restoration](_URL_2_) the theatres were reopened. Since Charles II had been exiled in France where female actors were allowed, he legalized professional actresses. The reaction against Puritan rule resulted in very explicit sexual comedy, and the theatre became even more associated with sexual license. Actresses appeared in what were called \"breeches roles\", to play women who were disguised as men, dressed in tight-fitting and revealing men's clothes. They became extremely popular, and rich and aristocratic rakes would compete to meet them after hours for sexual assignations. Charles II's favorite mistress, the popular actress Nell Gwynn, had a mother who ran a whorehouse, and it was rumored that Nell had been a child prostitute.\n\nGurr, Andrew. *The Shakespearean Stage 1574–1642*. CUP, 1992.\n\nHughes, Derek. *English Drama, 1660-1700*. Oxford UP, 1996."
]
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"http://en.wikipedia.org/wiki/Interregnum_%28British_Isles%29",
"http://en.wikipedia.org/wiki/English_Restoration"
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6zrqzl | how does a 3 month old baby learn the difference between laugh and a simple shout for the first time? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6zrqzl/eli5_how_does_a_3_month_old_baby_learn_the/ | {
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"They don't, really. Babies smile and laugh instinctively. It takes them a long time to learn what any of it actually means. If someone has a big, booming laugh that they are not used to, they may well startle and cry. Over time (months) they learn to interpret social signals based on the kind of response they get."
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1gxagv | base stealing in baseball | How does it work? When can players on base do it? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1gxagv/eli5_base_stealing_in_baseball/ | {
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"When a player gets on base, say 1st base, he can take a lead of the base. A lead can be a few steps, or a few more than that. It just means he is not physically touching the base with any part of his body. He may do this when the pitcher has the ball. This makes him closer to the next base. It's a regular thing in baseball. Now, the player can try to run while the pitcher has the ball or he can wait until the pitcher delivers his next pitch. The latter is the better option, since the pitcher could throw to the base the runner is trying to steal and the runner can easily be tagged out. However, if the pitcher throws the ball to the catcher, the runner gets a head start and the throw to get him out will come from the catcher (who is farther away than the pitcher from the bases). So most of the time, a stolen base will occur right after the ball is pitched. It is not a technical stolen base unless the defense tries to get the runner out (this is an MLB rule thing). A stolen base only happens if the ball is NOT hit. If the ball is hit, it's like a regular play."
]
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a2jw52 | How would a wealthy European individual or family around 1500 keep their home clean? What sorts of "cleaning products" would they (or rather, their servants) use? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/a2jw52/how_would_a_wealthy_european_individual_or_family/ | {
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"Follow-up: Today there is a taboo around having an unclean home. How would this issue be seen around that time? I'd assume the poor wouldn't have that standard, but would a wealthier individual \"lose face\" over this?",
"PART 1\n\nInteresting question! The first thing to note is that housekeeping and cleaning practices varied widely across different parts of Europe and different social strata in Europe in the early modern age. The cleaning of peasant households was a much simpler matter because custom, sumptuary laws, and plain old economics severely limited the furniture and possessions that a peasant owned (wood needed to be conserved for fires, agricultural activities, and maintenance of lords' forest hunting grounds, and could rarely be spared for such vanities as furniture), so housekeeping for peasants was mainly a matter of sweeping, mopping, and wiping surfaces with hot water and maybe some soap made of animal fat. For royalty, nobility, wealthy farmers, and wealthy merchants, it was another matter. Many travel guides from that era remark that Holland and Italy (particularly the upper classes) had some of the tidiest domestic practices. One of the theories about this is that they are both relatively humid countries, where wood is more likely to mold and rot if it is not scrubbed and polished.[1] However, Switzerland and some parts of Germany were also relatively known for tidiness. The historian Bas van Bavel makes a strong case that cleanliness correlated with the dairy industry. The dairy industry required greatly sanitary conditions, because it was easy for bacteria to get into dairy and ruin the product.[2]\n\nThomas Brockbank called early modern housekeeping the \"many-headed monster.\"[3] Thus, van Bavel cites numerous early modern travel journals that recounted the almost frantic cleanliness of servants and housewives in dairying areas like Holland, where they would sweep paths often, lay down cloth at thresholds to prevent the tracking in of dirt, make the men wear house slippers when they came inside, scrub and polish surfaces and belongings, wash and scrub clothing and linens, use hot water and soap, and dry their wooden cleaning buckets not in the sun but over a fire because they felt that that got the bucket cleaner than air drying (unbeknownst to them, they were onto something--although bacteria wouldn't be discovered until 1670, drying things with fire was much more effective at killing bacteria and preventing mold). Of course, there was usually great concern about the conservation of fire wood in early modern Europe, so resourceful servants and housewives would rather clean buckets using the fires from burning straw or peapods than making a fire specifically for cleaning (thereby \"killing two birds with one stone\").[see footnote 2 again] Kitchen utensils also had to be cleaned, and most of these cleaning techniques were passed on orally from generation to generation (and never written down), since servants were by-and-large illiterate in the early modern era.[4]\n\nVan Bavel further points out that of all the dairy products, butter is the most susceptible to ruination by bacteria and impurities, and since Holland particularly specialized in butter production, this made them all the more cleanliness-conscious.[5] Dairy-making and butter-making were not sufficient conditions for cleanliness however. Adam Smith noted in *The Wealth of Nations*, in the case of Scotland: \"If [the market price for dairy products] is very low, indeed, [the Scottish dairy farmer] will be likely to manage his dairy in a very slovenly and dirty manner ... [and] will suffer the business to be carried on amidst the smoke, filth, and nastiness of his own kitchen; as was the case of almost all the farmers dairies in Scotland thirty or forty years ago.\"[6] Van Bavel argues that making butter and other dairy products for market (requiring products that could last for weeks), rather than for personal consumption (which only had to last for several days), created a special impetus for Dutch dairy farmers to practice extreme cleanliness and hygiene, because Holland was such a commercial society oriented around long distance trade.[7]\n\nAlthough both men and women were responsible for cleanliness and hygiene at some level, women were--of course--seen as the ones ultimately responsible for cleanliness. Uncleanness was typically seen as due to a lack of women, and this was most pronounced in military settings.[8] Erica Longfellow quotes from Gervase Markham's *English Huswife* (1615), where Markham says: \"the perfit Husbandman, who is the father and master of the family, and whose office and imployments are euer for the most part abroad, or remoued from the house, as in the field or yarde ... [as well as] our english Hous-wife, who is the mother and Mistris of the family, and hath her most generall imployments within the house.”[9] \"Economy\" was a synonym for female housework in the early modern era, which Sara Pennell argues revealed the place of \"female expertise ... as an essential underpinning of economic survival and success.\"[10] This concept is still noticeable today where schools still have classes called \"home economics.\""
]
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84ooub | why do large indoor areas use one giant flat fan instead of a couple small fans? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/84ooub/eli5_why_do_large_indoor_areas_use_one_giant_flat/ | {
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"You get more bang for your buck when it comes to surface area: usually the single set of large blades can push more air than several smaller ones.\n\nIt also simplifies wiring & installation: when you have several fans you need to run several wires and drill several holes. The big guy is one and done.",
"The purpose of those big fans is not to \"blow\" air on the people in the area. They are instead for [destratification](_URL_0_). \n\nWhen you have a building with a high ceiling you end up with very different temperatures on the floor vs. up at the ceiling. This causes a couple of problems. If your area is something like a gymnasium with bleachers where you have people at different levels vertically in the room, the people on the bottom will be feeling a very different temperature than the ones at the top. \n\nAlso, if you have a large temperature difference from floor to ceiling, your heating system will be much less efficient and you'll spend a lot more money on electricity or gas to heat the area.\n\nLittle fans aren't powerful enough to get the air all the way down to the floor."
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2890wh | How did cold blooded reptiles survive (out living dinosaurs) during the ice age? | askscience | http://www.reddit.com/r/askscience/comments/2890wh/how_did_cold_blooded_reptiles_survive_out_living/ | {
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"The geologic era, the Mesozoic, in which the dinosaurs were present, contains no evidence for polar caps so there were probably no ice ages analogous to the Pleistocene (most recent glacial epoch). I.e., the Earth was warmer.\n\n_URL_0_ but no real good reference for the glacial thing, I'll look for one.\n\nEdit: [Here's a paper.](_URL_1_) From the first sentence in the abstract: \"The Mesozoic, perhaps representing the longest period of warmth during Phanerozoic Earth history, contains in general sparse and frequently equivocal evidence for polar ice.\""
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3wsk93 | Was the aircraft of ace fighters if WWII optimised for these specific pilots? | Especially in the Luftwaffe.
Were the aircraft such pilots such as Hans Rudel, given superior rear guns in his JU-87 or armour to protect these more important airmen? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3wsk93/was_the_aircraft_of_ace_fighters_if_wwii/ | {
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"Speaking for the American air force, the aces flew the same aircraft as any other pilot did. When you add extra armor to a plane beyond its design specifications, it can reduce speed and maneuverability. In the case of Rudel's Stuka (which was already quite slow) doing this would impose a significant weight (and thus speed) penalty and could stress the airframe in a dive, making him more vulnerable to Soviet planes and even his own aircraft. The factor of speed is even more important when flying a fighter versus a dive bomber. \n\nIn many cases, pilots (not necessarily aces, but aces often did as well) modified their aircraft to make them more comfortable to use or to give an advantage over the enemy; the 56th Fighter Group diligently waxed all their P-47 Thunderbolts to make them slip more smoothly through the air. The P-47 Thunderbolt's factory-fitted rear view mirror was not the best design, and so some pilots replaced them with mirrors from Spitfires. \"Bud\" Mahurin did just that, and attached two more spare P-47 mirrors to his plane below the windscreen on each side of the cockpit to give him a better rearward view; other pilots in the 56th Fighter Group did this as well. \n\n_URL_0_\n\n_URL_1_\n\nHis P-47, like some others, also had the flat wheel hub covers removed at some point as presumably unnecessary. The 20th Fighter Group, after they converted from P-38s, took the mirrors off their old planes and put them on their new P-51 Mustangs.\n\nWhen a fighter group was first constituted, each pilot had his own assigned plane. As the war wore on and casualties mounted, there were often more planes than pilots needed to fly them. This problem became more acute when fighter groups were authorized to expand from 75 to 108 aircraft in the winter of 1943-1944.\n\nPilots selected to fly a mission flew whatever aircraft was available that day, which sometimes would not necessarily be \"their\" aircraft. It was an unspoken rule in the Army Air Forces during the war that \"new\" (replacement) pilots weren't assigned their own plane until they had flown *x* number of missions or accumulated so many flying hours. Until then, they flew whatever aircraft was available. \n\nSources:\n\n*Zemke's Wolfpack: A Photographic Odyssey of the 56th Fighter Group During the Second World War*, by Nigel Julian and Peter Randall",
"I can answer a bit for the Navy, especially early war (1941-1942).\n\nBecause the situation was that there were never enough Wildcats on carriers to go around every pilot in the squadron from the CO on down would rotate, usually by flight or at least division if they had to. \n\nSo a squadron might have 30 pilots, but only 26 planes to start the cruise, then a month later only have 22. So you are going to have to rotate planes. Each plane in the squadron would be numbered and theoretically assigned a pilot base don position (F1 being the CO's plane F2 his wingman, F3 the other element leader in his flight, down the line). But when you have some planes under repair, others spotted quickly out of order on the flight deck, changes in plans or mission rosters, it all got very jumbled.\n\nThat isnt to say that they didnt have favorite or preferred aircraft, perhaps for whatever reason one Wildcat had a more efficient turbocharger, or one kept losing oil pressure every so often and wasnt liked, but in the end there werent enough planes at the time to be picky. \n\nAnd the F4F's flown early war (3, 3A, and 4) were all damn survivable aircraft that worked wonders to bring their pilots home to begin with. \n\nSource. The First Team: Carrier Fighter Combat from Pearl Harbor to Midway by Lundstrum. ",
"I can't remember his name, I think it was Alexander Pokryshkin, but there was a Soviet pilot who flew the lend lease planes and he made a modification to it. In the Bell P-39 Airacobra you could have 3 caliber weapons on the plane. Most common was a 37mm cannon in the propeller hub, 2x .50 caliber machine guns mounted in the nose cowling firing through the propeller, and 2x .30 caliber guns under the wing. There was a switch in the cockpit that could choose which gun to fire. This pilot ripped out the switch and wired it so that all his guns would fire at once. All that lead flying through the air you're bound to hit something, right?",
"In reference to your question, if planes of aces were modified specifically for them? No. Going with your example, Hans Rudel flew the Ju-87 and later perfected becoming a tank killer, first with bombs then with the G model armed with the 37mm cannons. The Stuka was a slow, stable platform for dive bombing. Because of its slow speed it needed the added \"protection\" of a rear gunner who could at most hope to scare away any attacking fighters let alone shoot one down. Hans Rudel did fly an FW-190 and achieved numerous kills in that, he even shot down soviet bombers that happened across his path in the Stuka, there was nothing that man wouldn't bomb or shoot.\n\nKeeping with this German theme Erich Hartman, the ace of aces with 352 kills, the only notable modification he added to his Bf-109 was the a black tulip on the nose. This eventually identified him to soviet pilots who avoided combat with him. He then would give his wing man the \"black tulip\" aircraft so they would not be interfered with while he went on racking up kills against the soviets.\n\nThe pilots just flew the planes they were given and depended on their skill as pilots to see them through, no special or \"superior\" weapons, or armor were given to them. Hans-Joachim Marseille the top scoring ace in North Africa, acquired the majority if not all of his 158 kills against the British, flew over 10 different Bf-109s and was killed jumping from his aircraft a Bf-109F-4 when the engine started smoking. A number of pilots did not care for the F model that came to the desert complaining of the problems the engines were having with the elements present in North Africa. \n\nWas the Bf-109 superior to other aircraft? At the start of the war yes, but by the end the only the K model could hold it's own against the newest fighters the allies had to offer. Why did the Bf-109 become the stable for the majority of the highest scoring aces? The majority of those high scoring aces achieved their kills on the Eastern Front against the hoards of aircraft the Soviets put up in the air piece meal. Of course there are exceptions notably the previous mentioned Marseille who scored all of his kills against western opponents. Just didn't want anybody thinking the Bf-109 was defacto the best fighter ever developed. ",
"As the other commentators here have indicated, even ace pilots tended to fly a roster of different aircraft. The modifications to the planes tended to be done not in the factory, but at the local airfield. Such field modifications tended to be relatively minor and reflected what pilots perceived as necessary for combat. There were very few examples of \"special\" ace custom aircraft during the war, and such that existed were not so much for special pilots, but to test the potential for these modifications to be incorporated into future production lines. One example of this was Adolf Galland's three \"special\" Bf-109 F-2s. As commander of JG 26, Galland had three of its Friedrichs modified to carry a heavier armament. Two of the [aircraft](_URL_0_) had their cowl MG 17s replaced with two 13 mm MG 131, while the [third aircraft](_URL_1_) had a two 20 mm MG FFs in the wings. But Galland had his mechanics make these modifications not because he personally wanted an up-gunned fighter, but rather because he felt that the BF-109F was undergunned for the average pilot's skills. As Galland was making his ascent up the *Luftwaffe*'s hierarchy, these modifications were a proof of concept rather than a perk given to an elite. ",
"Douglas Bader, the RAF ace who lost his legs in 1932, flew a slightly unusual Spitfire. The first mark of the Spitfire carried eight .303 machine guns (in what became known as 'A' type wings), but from 1941 the vast majority carried two 20mm cannon and four machine guns ('B' wings). Bader had always opposed the cannon armament, so when the rest of his wing were equipped with the Spitfire VB, he insisted on flying a Spitfire VA; this wasn't completely unique to Bader, but there were less than 100 Mk VAs built compared to more than 3500 Mk VBs, so it was somewhat atypical. For the most part, though, as others have said, aces flew standard aircraft."
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316r57 | How does time dilation work for an object between two gravitational attractors? | So for example if a space ship is flying between two black holes - in such a way that the black holes' gravitational pulls cancel out - how will their clocks compare to an outside observer's? | askscience | http://www.reddit.com/r/askscience/comments/316r57/how_does_time_dilation_work_for_an_object_between/ | {
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"The first thing to note is that there is only one point where the gravitational pull from the two black holes would be equal, everywhere else the pull from one would be greater than the other. Even if we're at that point, just because there is no NET gravitational pull does not mean there is no gravitational effects. \n\nThe easiest way to tackle this is to go back to basics, and examine the local space metric. The properties of the black holes (mass, charge, spin) will modify the local metric relative to an observer at infinity (in Minkowski space). The (not so simple) thing to do is to take the local metric from the two black holes and solve it for the proper time elapsed by you. Then solve the Minkowski metric for the proper time elapsed by your friend far away. Set them equal to eachother and solve for either your time (dt) or your friends time (dt2). The co factors in front will tell you how time has rescaled between the two of you.\n\nThis method also works if you want to figure out the time differences between you and your friend if you're both in relative motion since the metric takes into account displacements in time and all three spatial coordinates. "
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3qg88r | nihilism | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3qg88r/eli5_nihilism/ | {
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"Existential nihilism (the most famous one) is a philosophical doctrine which basically says that life has no objective intrinsic value, purpose or meaning. Moral nihilism says there is no such thing as an objective morality. Metaphysical nihilism says reality does not exist. Epistemological nihilism says that objectively true knowledge does not exist or that it is not possible to know anything for sure.\n\nEdit: Please stop telling me a 5yo would not get this and read the sidebar",
"In pure ELI5 terms :\n\nYou're eventually going to die, everyone's eventually going to die, the entire fucking universe is eventually going to die and nothing anybody ever did will matter at all, so pretending like it matters now is pointless.",
"Nihil is Latin for \"nothing\". So its Nothing-ism. Its the philosophical idea that nothing we do matters. That there is no ultimate true purpose to our existence or the universe's existence. Its the belief in nothing.",
"\"Life is whatever you want it to be, never let anyone tell you what you can't do.\"\n\nThis is the essence of nihilism. There is no objective truth, therefore no one is more or less right then you are. Create values you subscribe to, don't accept values only because they are accepted by others. No one is sitting on the \"right answers\".\n\nOne can choose to interpret this as \"there is no objective meaning with anything, I might as well kill myself\" or \"there is no objective meaning, and therefore I am not bound by any restrictions. I am free\".\n\nI can highly recommend nihilism, it might bring you peace if you are an atheist and question the meaning of existence.",
"Say what you want about the tenants of National Socialism dude... at least its an Ethos... -Walter",
"157 comments and not one reference to The Big Lebowski.\n\nI'm' disappointed, Reddit...really. ",
"Hey, why don't you try and earn a high score at pacman! That might be fun, right? Except periodically, I'm gonna push a button that resets your score to zero. Just to fuck with you. \n\nWait, you're just going to give up? Don't you still want to try and get a high score? No? \n\nI guess you're feeling kind of nihilistic. You feel like the game is meaningless now since in the end, you're going to have zero points, and there's no way to win and there's no purpose.",
"Modern philosophy evolved into a few main lines of thought. \n\n1. Life has no meaning and we can't give it any meaning -Nihilism\n2. Life has no meaning but we can give it meaning. \n3. Life has intrinsic meaning and there is a god. \n4. Life has intrinsic meaning and there may not be a god. \n\nSo a Nihilist says there is no point to life, we just 'are' and we can't give it meaning and anybody who says they can is full of it. Morality is just a convention and there is no right or wrong and all attempts at establishing morality, law, a moral high ground, right and wrong, are failed and flawed. \n\nThe most well known form of Nihilism are the Lebowskian Nihilists. They believe in nothing and they will pee on your rug; which is a shame because it really tied the room together. \n\n",
"A very old, very philosophical woman explained her nihilism to me once:\n\n\"You wake up, you cry for an hour, and then you go take care of shit.\"\n\nNihilism is the recognition that watching your grandparents die slowly and then watching your parents die slowly, forgetting your name in the process, is somehow the *ideal* state of things. And further, that this ideal state of things is rare -- in most cases, people are tormented by their loved ones dying out of order. Your younger brother dies before you -- who will answer the question 'why is this rare grief mine to bear?'\n\nNihilism is a philosophical response to how specific the miseries and degradations of grief are. After all, what system of beliefs can stand up to how arbitrary and sad and inflictive life is?\n\nAnother wise old woman (why are they always women?) once told me a story: \"I lost my wallet for 6 hours, and then I found it. The relief I felt finding it was not big enough to compensate for the stress I felt losing it. I went to bed that day agitated.\" What belief system addresses the deficit of comfort?\n\nIn the end, there is no way to explain nihilism to a 5 year old, or to most 25 year olds, or to any layman in human misery. The request is an oxymoron. You'll feel nihilism as a temptation when your circle begins to die -- first in exotic ways, then in ways we euphemistically call 'old age.'",
"Holy shit what? I read the top comment and it made sense for a micro second and then I tried to rationalize what I'd just read and concluded that I had no idea what I just read. ",
"I could explain it, but what's the point?",
"Why? It's not like it matters. It's not like anything matters. ",
"I think it's beautiful.\nBy saying that nothing has meaning, suddenly anything can mean everything. You're into fantasy football? That's suddenly your whole world, and it's ok. You like urban photography? Portfolio that shit, it's as important as anything else.",
"So Nihilism is basically the philosophy that applies to you when you've lost the innocence of your childhood and begin to realise the world is a nasty place and that people hurt each other for seemingly pointless reasons and no one cares on a larger scale because they have been so busy performing their jobs and life chores that they dont have time to care about things outside of their immediate personal environment which of course is pointless because they are just prolonging their innevitable pointless existence.\n\nI must be in my mid 20's........they told me this would happen when I was a teenager and I didnt believe them.",
"The origin of nihilism lies with Nietzsche. For him, Christianity was the ultimate nihilism since it ineluctably forgoes this life for one that, at the very least, you can't be certain exists. This leads to all sorts of selfish, thoughtless, brutal behavior. Such a doctrine is life-effacing rather than life-affirming, which is what Nietzsche strove for.\n\nNow Heidegger would say that Nietzsche is the ultimate nihilist since he brought us to one of the peaks of Being (Heideggerian language here), showing us that being = nothingness and that life is little more that forces coming together and breaking apart ceaselessly without reason. Heidegger's remedy for this was to suggest that meaning is an inherent quality of Being, rather and something which we bestow on things/people/values on a whim, that is to say, Heidegger rejects both that god gives meaning *and* that we decide meaning ourselves. ",
"You spend all your time on reddit, increasing your karma by posting great links and great comments. \n\nAnd then you realize that you actually don't benefit from a high karma, and you can't really do anything with it. You can't even use high karma to get a job at reddit.\n\nThe only ones that benefit are the owners of reddit who are making money off your hard work. \n\nAll your work and effort is meaningless and worth nothing. And nothing you did actually matters because 6 weeks from now no one will remember a single post or comment you made. \n\nYou are now a reddit nihilist.",
"Eh, what's the point?",
"I'm sure I'm not alone but don't feel like digging through the comments to see if someone else said it. I always saw it as, you're going to die, nothing matters, make the most of it while you can and do whatever the hell you want because we are all worm food in the end. ",
"Why do I get the feeling that we're helping op write his term paper?",
"Why bother explaining it? We'll all be dead soon.",
"Nihilism, in it's absolute simplist form, is the idea that \"so what?\" cannot be answered.\n\nI punch you in the face. So what? So you feel pain. So what? So you punch me back, maybe stab me? So what? I drive off the road. So what? What is the worst that can happen? I can get arrested. So what? I can die? So what? Maybe I'll go to hell? So what? Say we did send every Mexican back to Mexico, nuked the Middle East, and burned every single dollar bill. What *really* happens? Anarchy, hysteria, panic, death; so what? The world keeps on turning, in a thousand years it'd just be a footnote in history, everyone would be dead one way or another; and honestly, even if that wasn't true, and the world just fucking STOPPED, answer me - so what?\n\nThe bottom line is, we give things weight and morals, but it's all imaginary. Arbitrary. Man-made. Once man is extinct, what will everything we've ever learned or accomplished have meant? It is without purpose. Ultimately, the idea as it pertains to life, that we are all actors on a stage, compelled by a script we made up, and Nihilism is the sudden realization that nobody is watching.",
"Nihilism is a latin based word. It's prefix, nihil- literally means nothing. That is where the phrase *Ex Nihilo* (from nothing) comes from. It's suffix -ism has a ton of different meanings but the one that this particular word uses is the name of a system or school of thought, for example communism, capitalism, socialism, and Marxism.\n\nPractically, it is similar to atheism in regards to not believing in god. However, the key difference, as I recognize it, is that atheists generally believe in trying to be moral people. Nihilists simply don't. They tend to believe life is pointless and as a result of that there is no reason to attempt to be moral.\n\nSource: Nearly half a decade of Caesar's English and heavy research trying to figure out which belief system I subscribe to.\n\n**Edit: I seem to have forgotten this is an ELI5, Here is a more ELI5 answer**\n\nImagine belief in god is like a ball of Play-Doh. Imagine morality is a cube. Some religions keep the cube and others toss it out but all religions have that ball of play-doh sculpted into different shapes. Atheism keeps the cube but says \"I won't play with your play-doh.\" Nihilism basically says \"SCREW YOUR CUBE AND YOUR PLAY-DOH I DON'T WANT ANY OF IT!!!\"",
"Nothing matters. Not even the fact that nothing matters matters. Humans are likely to respond to this in an emotional way, but there is no good, objective reason to respond to it in any way. But we are bound by the laws of nature and must."
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jzw61 | - why does a fulcrum (lever) make something easier to lift? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/jzw61/eli5_why_does_a_fulcrum_lever_make_something/ | {
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"A lever is typically supported by a fulcrum. It is one of the six \"Simple Machines of Physics\". Typically, you take a lever and it is put onto the fulcrum.\n\nThink of a seesaw, but with the board more towards one side than the other, *not* right in the middle.\n\nIf you put a heavy box on the side of the board that is closer to the fulcrum, and you push down on the side that is furthest away, it will take less and less effort the *further* away it is.\n\nThat's the *how*, now here is the *why*. The longer the side of the board is that you're pushing down on, the shorter the other side is. What this means is that, while it takes less *force* to exert on the board, making the process easier, you have the trade-off of having to move more of the board as the angle becomes greater.\n\nThe object on the shorter side has to move a shorter distance than you do if you're pushing down on the board.\n\nAnother good example: the crowbar.\n\nYou pry it into a box lid. Think of the *tiny* amount of room the crowbar actually occupies in that crack in the crate's lid. Now think of how much room you have on your side? And of course, when you use the crowbar, you might have to push all the way down on it, to the point where your arm might make the crowbar go close to 90 degrees.\n\nSo this is a better example of where you exert less force, but have to move your end of the lever more.\n\n**tl;dr: The further away from the fulcrum the side you're pushing down on is, the less force you have to exert, but the further (distance) you have to move the lever (downwards/against the fulcrum) to see the result.**\n\n",
"I like to think of levers similar to how I think of ramps. Walking up a ramp is easier than climbing a ladder. At least it seems easier. The reason it seems easier is that a ramp stretches out the amount of upward force you need to exert over a longer distance. You wind up climbing for a longer time, but using less force at each step. \n\nA lever works on the the same basic principle. You apply less force over a larger distance. It is easier for most people to push down a 30 pound weight 20ft than it is to push a 300 pound weight 2ft. But both tasks require the same amount of energy. If you think of something like a crowbar, which has one really long side then a bend (the fulcrum) and a short side. If you push the long side down a long distance you can have the short side move a small distance but exert a lot of force. How ever many times longer the side you are pushing on is longer than the side exerting the force, is exactly how many times stronger the force being exerted is than the force you are pushing down with.",
"A lever is typically supported by a fulcrum. It is one of the six \"Simple Machines of Physics\". Typically, you take a lever and it is put onto the fulcrum.\n\nThink of a seesaw, but with the board more towards one side than the other, *not* right in the middle.\n\nIf you put a heavy box on the side of the board that is closer to the fulcrum, and you push down on the side that is furthest away, it will take less and less effort the *further* away it is.\n\nThat's the *how*, now here is the *why*. The longer the side of the board is that you're pushing down on, the shorter the other side is. What this means is that, while it takes less *force* to exert on the board, making the process easier, you have the trade-off of having to move more of the board as the angle becomes greater.\n\nThe object on the shorter side has to move a shorter distance than you do if you're pushing down on the board.\n\nAnother good example: the crowbar.\n\nYou pry it into a box lid. Think of the *tiny* amount of room the crowbar actually occupies in that crack in the crate's lid. Now think of how much room you have on your side? And of course, when you use the crowbar, you might have to push all the way down on it, to the point where your arm might make the crowbar go close to 90 degrees.\n\nSo this is a better example of where you exert less force, but have to move your end of the lever more.\n\n**tl;dr: The further away from the fulcrum the side you're pushing down on is, the less force you have to exert, but the further (distance) you have to move the lever (downwards/against the fulcrum) to see the result.**\n\n",
"I like to think of levers similar to how I think of ramps. Walking up a ramp is easier than climbing a ladder. At least it seems easier. The reason it seems easier is that a ramp stretches out the amount of upward force you need to exert over a longer distance. You wind up climbing for a longer time, but using less force at each step. \n\nA lever works on the the same basic principle. You apply less force over a larger distance. It is easier for most people to push down a 30 pound weight 20ft than it is to push a 300 pound weight 2ft. But both tasks require the same amount of energy. If you think of something like a crowbar, which has one really long side then a bend (the fulcrum) and a short side. If you push the long side down a long distance you can have the short side move a small distance but exert a lot of force. How ever many times longer the side you are pushing on is longer than the side exerting the force, is exactly how many times stronger the force being exerted is than the force you are pushing down with."
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2qkpdm | what is my "permanent record", and where is it located? | I always hear that something is going on someones permanent record.. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2qkpdm/eli5_what_is_my_permanent_record_and_where_is_it/ | {
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"The most likely meaning here is your education transcript. ( _URL_0_ ) \n\nhowever, this has been a long standing in-joke among educators, intending to scare students with the threat of irrevocable consequences. i.e. \"when you go to apply for retirement in 65 years, they will look at your permanent record and deny you because you were a very naughty child today\" ",
"A child gets a permanent record when they first enter school. It is where teachers keep and record your grades for that year, write comments about you for the future teachers and occasionally leave samples of your work. It stays at the school you are present at, each school usually had an office or offices that give teachers a file\n for their students that year, it gets sent to the new teacher the following year. When you graduate high school, you can get your \"permanent record\". My high school gave me mine when I graduated. "
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zrsmh | Do birds get charged with static electricity while flying? (air friction) | If so, do they get a shock when they land or touch other birds? | askscience | http://www.reddit.com/r/askscience/comments/zrsmh/do_birds_get_charged_with_static_electricity/ | {
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"What an interesting thought, I was in the service, worked on aircraft, all of them had static wicks to help discharge static el. The first thing that was done when an aircraft landed was to plug a static discharge wire to the ground. Why wouldn't a goose or some other migratory bird build up big charges of static as well? Saving to find out the answer (hopefully).",
"I don't know about birds, but honey bees build up a static charge as they fly through the air. They use it to their advantage when they land on a flower, pollen jumps up and clings to them when they land.",
"They should develop at least a little charge, due to the [triboelectric effect](_URL_0_). Air will do this, but it's not great at it. \n \nI suspect they won't tend to shock each other much, though. Feathers simply are lousy conductors of electricity, so the charge that each bird accumulates won't readily spread out, at least if the bird is dry. The charge on each bit of each feather will tend to stay where it is until it touches something of a different potential. (I don't know if birds' oily feather coatings change this.....it might.)",
"Could this translate to a skydiver? I've never jumped out of a plane. I wonder if they discharge any static electricity when they land. "
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1mbpbi | why do cheap restaurants often only have canned soda for sale instead of fountain soda, when the fountain soda has a much higher rate of return? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1mbpbi/eli5_why_do_cheap_restaurants_often_only_have/ | {
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"Because they don't have the money/space to install a fountain. Or they don't sell enough pop to want to have to worry about maintaining it/changing syrup bags/cleaning/etc.",
"It has a higher rate of return, but it also has a much higher up front cost. Cheap restaurants might not have the capital needed to buy one when they first open, and are saving up until they can afford to.",
"There is only a higher rate of return if you have a lot of customers purchasing it. There is a lot of overhead cost that goes into fountains that isn't there with cans.\n\nI'm going to pull some numbers out of the air just for example purposes.\nSay it costs $1000 for that machine, $25 for the syrup (first bag) and, I don't know, $5 for the cups.\nThat means the restaurant has to pay $1030 right now.\n\nIf they just go to Walmart and buy a 24 pack of canned soda, that costs $12 right now (I really don't know how much soda costs).\n\nSo, now the restaurant opens and say their first week they make $27 in soda sales (because they're a cheap, low-grade establishment).\n\nIf they have sufficient capitol, this isn't too big of a problem for the soda fountain guy because eventually he'll see a return on his investment (after about **9 and a half months** at this rate). At that point, he finally starts to actually see profit off of the soda fountain.\n\nIf you don't have the length of a pregnancy to wait to see profits (you shouldn't be opening a restaurant in the first place) then that soda machine is going to seem like a bad investment to you.",
"A fountain requires a largish initial investment, and often a contract with a soda company.\n\nCans require a trip to the grocery store."
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4ojorw | graphene aerogel. if it is 7 times lighter than air, shouldn't it float? | I'm having a hard time grasping the concept. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4ojorw/eli5_graphene_aerogel_if_it_is_7_times_lighter/ | {
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"If, in total, it's less dense than air, it should float. Sometimes, by lighter than air, they mean that if the aero gel had cells of vacuum instead of cells of air, it would be lighter. But it's filled with air, so in total, it heavier. ",
"The aerogel has a lot of empty space in it. Air typically fills that space, and when it does so the resulting density of the entire object is not less than that of air. The claim that it is \"7 times lighter than air\" is true, but only really applies if you suck all the air out of the empty spaces in the aerogel.\n\nYou can analogize it to a ship. A ship as a whole is lighter than water, but if you fill the empty spaces with water instead of air it will no longer be denser than water. The aerogel is lighter than air when there is a vacuum and essentially nothing is filling the empty spaces in the material, but when air fills those spaces it is just a little denser than air."
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7hk5wi | why does autotune sound so bad in 2017? | It’s 2017. We have smart-everything now. Autotune has sounded the same since 2000s. How come it hasn’t improved since?
Side question; why does autotune sound so bad in the first place? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7hk5wi/eli5_why_does_autotune_sound_so_bad_in_2017/ | {
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"Autotune has been used, unbeknownst to the public, long before Cher's Life After Love, which is commonly credited as the first song to employ apparent autotune. Before then, it was simply used to correct pitch in studio performances. When applied thusly, it is nigh unto undetectable. When you can hear the autotune, that's intentional.",
"Producers and sound engineers are very able to use Autotune and other pitch-correction software without leaving electronic-sounding artifacts. It's sometimes a stylistic choice to include them, and it's sometimes the fact that for lots of people a little Autotune sound doesn't bother them and so it's wasted time and effort to keep making it sound better in the rush to produce the next pop industry album.",
"99% of the time you don't hear autotune/pitch correction when it's used as a tool and not as an effect. It's gotten really, really good and it's integrated into most recording software. Back in the day you needed a hardware unit or third party software, now it's a standard feature and it's used so much you wouldn't believe it. It's primarily used when you have a take with a few notes that are out of tune slightly and need to be fixed, which is cheaper than booking studio time or a musician to redo the takes. \n\nWhen you hear it like you're talking about, it's used as an effect. You may think that it's a cheesy effect that sounds bad, but artists make a conscious decision to use it in that way because they think it sounds cool. It can be used as a callback to tunes they were influenced by or are trying to emulate from the early 2000s. But it's just that, an artistic effect. If you don't like it in music don't buy that music. \n\nThe reason it sounds \"fake\" is twofold, the first is the actual pitch shift and the second is how it is applied to the audio. \n\nThe sweeping majority of pitch correction software essentially time stretches the audio (without changing pitch) and then plays it back faster or slower by the same factor. Both stages will have artifacts, or add crap you didn't want. Time stretching without shifting pitch is an old idea (it was done back in the 50s) but one of the things that happens is transients (fast changes in the signal envelope) get smeared or shrunk in time, and in bad cases can even be repeated giving you some pops and blips. When you speed up the signal after stretching it, you have to filter it or else you get \"aliasing\" which is high frequency garbage on top, if you slow it down you naturally filter the signal which rolls off the high frequencies.\n\nNow *even if* you have no artifacts from the shift, you have a problem which is that the general curve of the frequency response is shifted up or down. This is not how a real instrument works, where the curve is fixed based on the acoustics of the instrument/voice, but the individual harmonics move up and down. This causes the timbre of the instrument to shift with the pitch changes, and it sounds alien and unnatural. \n\nIn general the only way around those problems is to only use tiny pitch shifts. Which is where autotune excels today, it's great for fixing tracks that are out of tune, not for changing the melody entirely. \n\nNow when the shift is applied it is done with an envelope, meaning the pitch shift is applied over time. The signal will ramp up or down to the new pitch, it isn't instant. The longer that ramp time, the more natural it sounds. When it's very short you get that T-Pain sound, as the pitch correction kicks in almost instantly rather than how a voice would naturally change. ",
"I dont think its necessarily the autotune that sounds bad. but alot of artists not using it the way its supposed to be used and having it pitch correct at the wrong time etc. "
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6bmx7w | Did the Battle of Thermopylae happen on the same day as the Battle of Artemisium? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6bmx7w/did_the_battle_of_thermopylae_happen_on_the_same/ | {
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"According to our best available source - the historical account by Herodotos of Halikarnassos, written some 40 years after the event - this is indeed what happened. The army and fleet were sent to two adjacent bottlenecks and fought to prevent each other getting outflanked. Both battles continued over the span of the same 3 days. The naval battle ended in a stalemate, but when it became known that the land army had been defeated, the Greek ships withdrew."
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8widrx | why during the 60s british bands put out different albums in the uk and us | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8widrx/eli5_why_during_the_60s_british_bands_put_out/ | {
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"At the time British bands would have to sign separate deals with US record labels to get their albums distributed there, and those labels would have had their own ideas as to what songs to put on the albums to best cater to the US market"
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qjfly | How can a device be more than 100% efficient? | I read this synopsis of an experiment ([link](_URL_0_)) and it says that "Physicists have known for decades that, in principle, a semiconductor device can emit more light power than it consumes electrically." I don't quite understand how a system could produce more energy than it uses, especially more than twice the amount that were originally induced (70 picowatts were emitted whereas the system was given only 30 picowatts).
I was then wondering how this could be, and where this energy came from. The article gives the following explication: "The extra energy comes from lattice vibrations, so the device should be cooled slightly, as occurs in thermoelectric coolers." but I have no idea what this means, so I would appreciate an explanation in layman's terms.
Thanks a lot!
(I looked if something similar had been posted previously and found nothing, so I hope this is not a repost.) | askscience | http://www.reddit.com/r/askscience/comments/qjfly/how_can_a_device_be_more_than_100_efficient/ | {
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"What they are saying is that some of the energy is coming from heat. The device isn't putting out more than it takes in when all sources of power are combined; it takes a little bit of heat from the environment as well as the electrical energy."
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63nx0n | After Germany's surrender in WW2, did the US send the remaining forces from Europe to go fight in the Pacific or was there too much of a difference compared to fighting Hitler's forces to be effective against the Japanese? | The title may be confusing so I'll try to clear it up. I know there were two seperate fronts basically in WW2. You had the European/African front and then you had the Island/Jungle front. Were soldiers trained differently depending on which enemy force they were going to engage or was it simply adapt as you go. I also wanted to know if they just took all the survivors from Europe to go assist the Pacific forces once Germany surrended. I can't find much online about this. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/63nx0n/after_germanys_surrender_in_ww2_did_the_us_send/ | {
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"Immediately after World War II in Europe ended, U.S. units there were classified into four categories;\n\nCategory|Explanation\n:--|:--\nI|Units to remain in Europe (the occupation forces)\nII|Units to be redeployed to the Pacific for the invasion of Japan. Some soldiers were to go directly there (the 86th Infantry Division, having fought in Europe for only 34 days, was guarding POW pens in the Philippines on V-J Day!) while others were to train back in the USA for a while before deploying \nIII|Units to be reorganized and retrained before being classified as Category I or II\nIV|Units to be sent home and inactivated with personnel discharged\n\nI talk more about the \"points\" system used for sending long-serving men home [here](_URL_0_)\n\nOfficers also received an ASR score, but were not evaluated based solely on points earned for demobilization; combat effectiveness played an extremely significant role, and many officers who fought in Europe expected to be sent to Japan. The initial landing forces of Operation *Majestic* (the invasion of the Japanese home island of Kyushu, to be used as a staging ground for the invasion of Honshu island, where Tokyo is located) consisted of Army, Navy, Marine, and Coast Guard forces already in the Pacific. This landing was scheduled for X-Day, November 1, 1945;\n\n**U.S. Sixth Army:**\n\nLanding location|Corps|Forces\n:--|:--|:--\nNakakoshiki Ura and Koshiki Retto (X-4)|N/A|40th Infantry Division, 148th RCT\nKushikino|V MAC|2nd, 3rd, and 6th Marine Divisions\nAriake Bay|XI|1st Cavalry Division, 23rd and 43rd Infantry Divisions, 112th Cavalry RCT\nMiyazaki|I|25th, 33rd, and 41st Infantry Divisions\nN/A|Floating reserve to be used as a diversion on X-2|77th, 81st, and 98th Infantry Divisions\nN/A|Follow-up|11th Airborne Division\nUS Army Forces Pacific Reserve|N/A|6th, 7th, and 96th Infantry Divisions\n\nY-Day for Operation *Coronet* (the invasion of Honshu) was scheduled for March 1, 1946, and would have utilized forces still in the Pacific as well as some of the more veteran units redeployed from Europe, bolstered with fresh replacements to take the place of those men who had \"pointed\" out;\n\n**U.S. First Army:**\n\nCorps|Forces\n:--|:--\nIII MAC|1st, 4th, and 6th Marine Divisions (6th available from Y+5)\nXXIV|7th, 27th, and 96th Infantry Divisions (96th available from Y+5)\nFollow-on corps transferred from Europe|5th, 44th, and 86th Infantry Divisions\n\n**U.S. Eighth Army:**\n\nCorps|Forces\n:--|:--\nX|24th, 31st, and 37th Infantry Divisions (37th available from Y+5)\nX (Commonwealth)|3rd British, 6th Canadian, and 10th Australian Divisions, plus two unnamed British divisions to be available from Y+40\nXIII (lands on Y+10)|13th and 20th Infantry Divisions\nXIV|6th, 32nd, and 38th Infantry Divisions (38th available from Y+5)\nFollow-on corps transferred from Europe|4th, 8th, and 87th Infantry Divisions\nU.S. Army Forces Pacific Reserve|11th Airborne Division, 97th Infantry Division (11th available from Y+35)\nUnnamed reserve corps transferred from Europe|2nd, 28th, and 35th Infantry Divisions\nUnnamed reserve corps transferred from Europe|91st, 95th, and 104th Infantry Divisions\n"
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sgby7 | How much neutron star material would it take to equal the mass of earth? | From _URL_0_ "A neutron star is so dense that one teaspoon (5 milliliters) of its material would have a mass over 5.5×1012 kg, about 900 times the mass of the Great Pyramid of Giza."
This made me wonder how much neutron star material would it take to equal the mass of earth?
Also, if you were able to break off a piece with mass equal to the earth, would it expand, stay the same size or explode?
Sorry if these questions are ridiculous. Neutron stars (like much of the universe) boggles my mind!
| askscience | http://www.reddit.com/r/askscience/comments/sgby7/how_much_neutron_star_material_would_it_take_to/ | {
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"Taking the density at 4.5×10^17 kg/m^3 (there's a range of possibilities, but that's about average), a neutron star with Earth's mass would have a volume of 13,276,000 m^3 , equivalent to a sphere of radius 146 metres.\n\nIf isolated from the neutron star's gravitational pressure, a small section of neutron star matter would likely decay fairly rapidly to normal matter, but we don't know very much about the true structure of material in a neutron star, which makes it difficult to predict its behaviour in different scenarios.",
" > how much neutron star material would it take to equal the mass of earth?\n\nWell, the mass of Earth is 5.9736×10^24 kg, so you'd need about 1.086 x 10^12 teaspoons of your neutron star material, which works out to be 5,353,000 cubic meters. You could fit that inside eleven oil supertankers.\n\nEDIT: I think my math might be wonky. Can someone double check here? Think I need more coffee.",
"Wolfram alpha is great at [these kinds of numerical questions](_URL_0_)\n\nWA says between 3-75 million cubic meters",
" > Also, if you were able to break off a piece with mass equal to the earth, would it expand, stay the same size or explode?\n\nA mass of neutron star matter less than 0.1 solar masses is thought to be unstable. It would explode.\n\nEdit: ref [Physics of Neutron Star Interiors](_URL_0_)."
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4pq5bi | How does our brain know what pitch a note is gonna be before we sing/whistle it? | askscience | https://www.reddit.com/r/askscience/comments/4pq5bi/how_does_our_brain_know_what_pitch_a_note_is/ | {
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"Practice. Firing a certain set of vocal motor neurons produces a certain pitch, which then stimulates certain auditory neurons via our hearing, as well as the integrative neurons that process the sound. Frequent simultaneous stimulation of those three sets of neurons, but particularly the motor and integrative neurons, produces a link between them. This link makes it possible for the stimulation of one group to stimulate the other in turn. Thus, when we think about a certain pitch, this stimulates the set of motor neurons required to produce that pitch, and a stronger bond means better pitch. The technical term for this process of bond formation is recruitment, although it's usually applied to individual motor neurons syncing up so that the fibers in a muscle will work together more efficiently."
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ljd2u | how a photocopier works. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ljd2u/eli5_how_a_photocopier_works/ | {
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"A very bright, intense light is flashed at the original document. This light is then reflected onto a negatively charged metal drum, which through various quantum mechanical effects causes it to lose its charge where the light hits it. This means that where there was ink (and therefore less light reflected) the drum still holds a charge. Ink is then passed over the drum, which attracts to the charged areas and is transferred onto a clean sheet of paper.",
"A very bright, intense light is flashed at the original document. This light is then reflected onto a negatively charged metal drum, which through various quantum mechanical effects causes it to lose its charge where the light hits it. This means that where there was ink (and therefore less light reflected) the drum still holds a charge. Ink is then passed over the drum, which attracts to the charged areas and is transferred onto a clean sheet of paper."
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vj7gy | The modern American "foodie" movement | Even if you aren't a historian, I am interested in pretty much any perspective on this. So if you are older than, say, thirty I would love to hear your comment--just be sure to note what region you are in.
If I go to a normal American grocery store, I can usually find well over a dozen types of beer, wine from every major producing region (except Greece, *sigh*), dozens of cheeses, a bakery that makes fresh bread and a deli with a large selection of Italian meats. For restaurants, there is a ubiquitous type that I guess we can call "mid range", which can be [gourmet takes on mundane foods](_URL_1_) or [interesting fusions](_URL_0_). Food trucks are getting popular, as are lesser known cuisines (Ethiopian, for example), and well known cuisines are getting transformed due to a surge in "authenticity". This can also be seen in the rise of grocery stores like Whole Foods and Trader Joe's, and chain restaurants like Five Guys and Doc Green's.
This is, I am given to understand, a fairly recent phenomenon in the US (at least outside of areas like New York and San Francisco). I have been told that, at least in the south, good wine was very difficult to find until the 80s. Bread started coming in varieties besides plastic-and-processed in the early nineties, and the draft beer movement is apparently only about fifteen years old.
I am wondering what caused this, actually quite radical, change. A few possibilities I have come up with: the health food movement drove people from traditional American cuisines, increased tourism brought greater exposure of different food to more people, the increased wealth of the 90s allowed for a greater expenditure on food and drink, and maybe there were some movies, books, or TV shows that caused a change in perception.
It just seems like such a fascinating movement. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/vj7gy/the_modern_american_foodie_movement/ | {
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"A few ideas, but I can't approach the subject entirely. \n\nBeer and Wine: There have always been hundreds of different styles of beer throughout history. Beer typically has always brewed in your town, or the town over. It didn't travel well until the advent of pasteurization, refrigeration and the reliable, durable bottles and cans. Every region (especially in Central Europe) had their own style of beer. Almost every region of the US settled by these central europeans (Czech, German, Belgian, Austrian mainly) had a brewery. Beer was also brewed at home throughout history, typically by the woman of the house. Therefore, depending on local ingredients (beer wasn't always made with hops or barley, depending on location) there were wildly different flavors. \n\nBefore prohibition, there were over 1,000 breweries in the United States. Many of these breweries had to shut down because of Prohibition and only a handful survived by making other products. Medicinal alcohol, malt beverages (unfermented wort, basically) and prepackaged malted grain (that could be fermented at home). These breweries that survived are the ones most people know today, Anheuser-Busch, Miller, Coors, Pabst. These Breweries were all making lager beer. \n\nLager arrived in the United States with German immigrants, and Americans enjoyed it immensely. Previous, most beer in the US was English Style Ales, which were easier to produce than lager. Lager requires colder fermentation and longer fermentation time to produce a high quality beer. \n\nBud, Miller and Coors often get a bad rap for making \"cheap\" beer and training us to like it, but they really made it because Americans loved it. I'm sure the original founders of these breweries would have loved to make their traditional German bocks, dunkels and hefeweizens, but Americans loved lager. \n\nSo, they emerged from Prohibition unscathed because they were able to transport their product across the country using refrigeration technology and cans and bottles. Therefore, everyone could have a great taste of this lager. After prohibition, they jumped on the chance and were able to claim the beer market across the country. With control of the market, they were able to advertise themselves well and prevent any competitors. They introduced the idea that the only real beer is their product. \n\nNow, after the legalization of Homebrewing beer in the late 1970s, many people upset with the diversity of beer in the US began making their own. Some were incredibly good at it, passionate about it and had the resources to produce commercially. This gave rise to the first craft beer renaissance in the 1980s. The second wave came in the 1990s, and now we're into the third wave, which has a focus on drinking local, and using local ingredients. \n\nAs I remember, the United States now has just about the same number of breweries as it did pre-Prohibition. They're reintroducing styles and flavors that had been practically lost from the 20s to the 90s. The idea that drinking imported or flavorful beer is snobby and unAmerican is mostly gone, and we're returning to a diverse market with a focus on the local economy. Granted, craft beer and microbrews are still less than 10% of total beer sale.s \n\n\nOk, I typed way more than I thought I would about beer. Here's some other concise ideas. \n\nWine: It's a lot easier to legally open a vineyard in the states than a brewery. Making wine at home was legal long before homebrewing. Advent of international transport and industrial agriculture allows wineries the world over to grow similar styles of wines with the same grapes as the famous Regions of France and Italy. \n\nFood: Food pathways are extensively discussed in geography. I recommend finding some papers in the AAG journal. ",
"In the 1990s food writers, college professors, and environmental activists educated the American public and food producers about the risks of monocultural agriculture. The most well-known spokesperson for multi-cultural food production is Michael Pollan, author of [The Botany of Desire](_URL_1_). \n\nMonocultural agriculture means the production of a single consumer-ready variety of any plant. Before the 1990s you could generally only buy Russett potatoes, for example, because that was by far the most abundantly grown variety. This single variety method was profitable and efficient in the short-term, but also very risky because farmers' entire investments were devoted to one crop. When only one crop is grown, synthetic fertilizers and pesticides have to be used to ensure a farmer gets a return on his investment. Growing 5 different kinds of potatoes can be done with less synthetics because the risk to the producer is divested.\n\nThis divested and low impact multicultural method, however, produces lesser quantities of food per acre. This means higher prices for consumers. Luckily, enough Americans paid the higher price to have less toxic, less environmentally deletrious, and better tasting food. The varied grocery store shelves you see today are the result of this. \n\nIn short, it took the actions of producers, consumers, and food academics to change food choices for Americans. This is obviously a very simple summary, but if you'd like to read more about this history of American food habits I would recommend any of Michael Pollan's books and especially Ted Steinberg's environmental history text, [Down to Earth](_URL_0_).\n\nEDIT: Clarification of historical potato availability in America in regards to mussscrott's comment.",
"My research is deeply tied to this question, but it's far too late here for me to write up a response. As such, I'll edit this post in the morning. For now, I'll just say that I think there are really deep connections between this and issues of class, gender, and perhaps race. To be honest, I'm not sure exactly what these connections are, because they often appear in contradictory ways. So, I'll sleep on this and then give you a thorough answer tomorrow. It'll give me a chance to digest some of the material that I've been working on anyway.",
"Since you've asked for \"pretty much any perspective\" on this topic, I'm going to go quite a ways back, to the industrial revolution. I think this will give us some insight into the contemporary food scene, which we might say involves everything and anything from microbrews, organic food, and fusion cuisine. However, I'll say up front that I offer few conclusions. I have a good idea of British food history in the 19th and 20th centuries, which has a lot of applicability to the Dominions and the United States, but obviously there will be regional differences. I'm going to discuss these issues through the one lens that I know best, wheat and bread.\n\nSo, what are the contemporary food movements all about? One way to think of them is as a reaction to the last two hundred years of industrialization, a kind of critique of the world that the 19th century left to the 20th. However, this critique--like all social, cultural, and political movements--reflects a set of power relationships between groups of people. I'll say up front that I am myself a part of this movement. I eat organic food whenever possible, I do a portion of my weekly shopping at Whole Foods (though probably less than a quarter), I love food trucks (as an LA native), I garden, and I never, ever eat Wonder Bread; that said, I recognize that there are real problems with the contemporary food movement, though problems that are surprisingly familiar to the historian.\n\nSo, if we go back to the late 18th or early 19th century, we find a world in which most people--in Britain and America, in Europe and indeed around the world--grew their own food. Britain was the first nation to be majority urban, but that wasn't until 1851, and I don't believe the United States crossed that line until about 1920. And that's with a definition of \"urban\" as residing in a city of something like 10,000, a pretty small town by contemporary standards. In those days, food production and food processing was quite local. Everyone was a \"localvore,\" of necessity. As others have said on here, people brewed their own beer, grew many of their own vegetable, milked their own cows. Certainly there was long-distance trade in particular high-value food commodities like wine, spices, or sugar, but for the most part people took care of their own food needs from their immediate area. It was simply too expensive to transport food very far. \n\nThis all changed in the 19th century, and there were several interlocking changes that radically transformed the food systems of the Anglophone world (at least; much of this is probably true for most of Europe, but I just can't say with much confidence). To really boil things down, these changes were agricultural expansion, steam technology, and developments in agricultural techniques. \n\nSettler colonies expanded dramatically over the 19th century, in the United States most dramatically, but also in Canada and Australia. In those three cases, you had Europeans conquering and displacing indigenous populations who had been previously reduced through disease. At the same time, there was an expansion of irrigation systems in British India, particularly in the Punjab. The net result of these changes was there was a lot more land under cultivation. I don't have access to my library at the moment, but I believe the land under cultivation more than doubled from about 1850 to 1914, on top of pretty substantial expansion in the previous century.\n\nAt the same time, the construction of railway networks pretty much everywhere dramatically reduced shipment costs. These really start to have an effect in the US about 1870--as far as food transport goes--and then everywhere else follows. Steamships come along slightly later, though sailing ships remain important until the 20th century. In any case, it becomes much easier for farmers around the world to transport their goods to markets, and remember that much more land is under cultivation. Railways bring all that new American, Canadian, Australian, and Indian land into an emerging global grain market. Railways also made it much more profitable to export grain from places like eastern Europe and Russia.\n\nFinally, farming gets more capital-intensive and more productive (per acre in some places, per laborer in others), thanks to developments like Justus von Liebig's publication of the NPK factors in plant growth (the idea that Nitrogen, Phosphorus, and [K]Potassium are the limiting factors in plant growth). Recognizing that the level of nitrogen in the soil could have profound effects on plant growth encouraged farmers with sufficient capital to begin mining nitrogen-rich bird waste from islands and putting it on their fields. By World War I, Fritz Haber had developed a way to synthesize amonium nitrate from natural gas, meaning that you could turn fossil fuels into fertilizers. There were also important developments in agricultural machinery; the McCormick reaper was patented in (I believe) 1843. \n\nSo, the bottom line is that world was capable of producing much more food in 1900 than in 1800--and I mean MUCH more; I've never seen anyone actually compile global agricultural statistics (maybe Giovanni Federico?), but it wouldn't surprise me if it was an order of magnitude. All this food can also be transported much more efficiently than ever before. AND, this all happens in the Western world where farmers were already pretty productive; Britain was the most urbanized nation from the 18th century, and this was a precondition for industrialization in the first place. So, a local surplus that allowed 18th-century Britain to begin industrializing became a global surplus that made possible the creation of an urban, industrial “core” for the world: the North Atlantic, basically the northern and eastern US and Canada, and northern and western Europe. All the food produced elsewhere in the world was funneled to these places, and in particular to Britain, whose cities grew the fastest and whose agriculture declined the most. Again, I don't have my library handy, but Britain imported something like half of all the grain traded internationally in the last half of the 19th century. I'm sure the situation was quite similar for the eastern industrial cities of the US, it's just that the grain didn't cross international borders.\n\nSo, we know that the world's food supply basically globalized in the 19th century; most of the action went down from about 1850 to 1914. Let's stop a moment and consider food from a cultural perspecitve. What does bread MEAN? Well, food has often played a role in marking identity, so that people of different groups eat different things. It's not so much that you are what you eat, but what you eat displays who you are.\n\nIn the case of bread, if you were wealthy, you ate white bread. White flour was harder to manufacture and you didn't get as much, so it was more expensive; whether humans have a natural proclivity to white flour over brown is impossible to say, in my view. In any case, the wealthy ate white bread, and the poor ate brown bread. And, when the poor did eat white bread, they were often criticized for being uneconomical. They were essentially being told, “well, no wonder you're poor, you're eating fancy bread, bread that's above your station.” The examples of this discourse I'm most familiar with are in the 19th century, with people like William Cobbett and Eliza Acton. \n\nHowever, industrialization does a funny thing to bread. Right at the same time that the world was creating a global market in grain, flour millers industrialized their business. They switched from millstones to steel rollers (I know I've posted the story of this particular change on here before, which has a lot to do with particular environmental conditions of American and Canadian and Russian wheat, but I can't be bothered to dig it up now). Rollers made is much easier to produce a lot more white flour, and so it became possible for everyone to have white bread. So, with white bread available for everyone, what do you know, brown bread becomes a mark not of poverty, but of sophistication, or informed choices. The old reddit switcheroo happened with bread in the late 19th century. This, in my view, is at least one of the roots of the current food culture. \n\nPart II will have to come tomorrow, I've just had a day that was much too long to keep this up. "
]
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"http://www.delseoul.com/",
"http://en.wikipedia.org/wiki/Hot_Doug%27s"
] | [
[],
[
"http://www.amazon.com/Down-Earth-Natures-American-History/dp/0195331826",
"http://www.amazon.com/The-Botany-Desire-Plants-Eye-World/dp/0375760393"
],
[],
[]
] |
|
393bnp | Were Catholics before the Reformation aware of how corrupt their church was at the time? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/393bnp/were_catholics_before_the_reformation_aware_of/ | {
"a_id": [
"cs0c57r"
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"text": [
"The everyday Joe? No. \n\nThe Catholic Church before the Reformation was great at keeping its corruption a secret on the higher levels, but the corruption within the lower levels was less well kept.\n\n-In local communities, if you were wealthy enough you could buy indulgences, or you could buy yourself a \"clean slate.\" You would pay the priest, donate to the church, or the local church authority, and you could be cleared of any past wrongdoings. The logic was that you did not tell anyone you paid for being cleared, and that paying to the church was a sign of asking for forgiveness by giving money to the cause of the church. However, people did begin to figure out that local churches/officials were corrupt and selling these slates to people.\n\nBut that is not the end of the corruption. \n\nThe full grasp of corruption-\n\nMany peasants and commoners did not know how to read in their native language, let alone in Latin- which every Bible was written in. This was more exposed by the printing press when bibles were first begun to be printed in other languages, allowing for people to be able to actually read from them. The reason this is such a large deal is that before, only the educated rich and nobility, and members of the clergy could read Latin, and could basically claim many things were in the Bible, and then conveniently allow other things to go unmentioned. This actually was covered up for a while due to the lack of education and lack of bibles until the printing press beginning to mass manufacture them, as well as literacy rates rising because of the printing press. Although I'm not sure of the exact wording of claims, many dealt with money, with the idea that the current ruler had divine power from God to rule over their country, that conditions were actually ideal and commoners should not attempt to improve them, etc.\n\nAnd of course political corruptness- which even many members of the nobility and low ranking clergy did not know about. The Catholic Church was a huge power in Europe during its height, and even after- directly influencing, and could be argued to be controlling the Austrian, Spanish, and Holy Roman Empires, as well as many Italian city-states, German provinces, and before the reformation, English lands. An example of said influence over the Spanish empire was that in the Southern American colonies, natives could first be enslaved BUT the policy changed after the church declared that no converted native could be enslaved- initially against the Spanish's wishes, who eventually accepted, which combined with natives not being \"suitable for physical labor\" led to the growth of importing African slaves- who were deemed by the church to not be human, and not be capable of conversion.\n\nAnyway, this political corruption lasts from directly influencing governments in Italian city-states, having links with both monarchies in established empires, as well as the governments of individual provinces and cities. the Italian city-state Florence for example had its government incredibly linked with the Catholic Church, many officials being members, or associated with members of the church- the crimes of individuals linked with the church often went unpunished or unheard of until a large amount of time had already passed.\n\nIn short- the people doing it, and very high ranking nobility were aware, as they directly benefited from the corruption. the average Joe only could know of the corruption at the local level (which was actually classed as corruption in the Catholic Church, despite it being a large source of income for many small/local churches) The corruption came in political, economic, and social \"waves\" and was expressed differently, and of course when the corruption began to be learned about more, we see an alternative- Protestantism begin to become popular in areas where corruption was exposed more. Even after the reformation, the Church still retained massive amounts of power, but now with a rival, and a large amount of land lost due to Protestants taking over England, ruling over Ireland, and German nobility being allowed to choose between Catholicism and Protestantism to be followed within their lands, power was lost.\n\n"
]
} | [] | [] | [
[]
] |
||
zyx6f | Can habitual nose picking enlarge the nostrils? | askscience | http://www.reddit.com/r/askscience/comments/zyx6f/can_habitual_nose_picking_enlarge_the_nostrils/ | {
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"c68xniy",
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"text": [
"Related: Can habitual nose picking in one nostril but not the other cause a deviated septum?",
"Well, the literature is scarce on this topic. So, as far as I can tell, no.\n\nHowever, of note, there was a case of a woman who [self-induced ethmoidectomy through nose-picking, and perforated her septum](_URL_0_). This was connected directly to her history of nose-picking, or \"rhinotellixis\" or \"rhinotellixomania\". This was reported in the American Journal of Neuroradiology.\n\nTerms:\n\nethmoidectomy: to enter the ethmoid sinuses, which are superior-anterior to the nasal passages.\n\nperforate: to tear, in essence.\n\nEDIT: [Link to full text article!](_URL_1_) Excellent.\n\nHere's an awesome picture from the article, for those who are too lazy to click on the link to the full text .pdf.\n\n_URL_2_",
"what about constant bloody noses and the use of tissue plugs to stop it? my mom always made fun of me for \"gauging out my nostrils\" because of how much i had nose plugs in so i didn't have to stop doing things whenever i had a bloody nose in the morning...so what about that?"
]
} | [] | [] | [
[],
[
"http://www.ncbi.nlm.nih.gov/pubmed/9403460",
"http://www.ajnr.org/content/18/10/1949.long",
"http://i.imgur.com/b8vfbh.jpg"
],
[]
] |
||
37luhg | why don't we have atomic powered aircraft? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/37luhg/eli5_why_dont_we_have_atomic_powered_aircraft/ | {
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"crnrhvx"
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"text": [
"We tried. In the Cold War the USA did work on trying to make a nuclear powered bomber. They actually did put a reactor in a plane. \n\nToo many problems, and it irradiated the ground crew. Plus it actually didn't make a very fast plane. "
]
} | [] | [] | [
[]
] |
||
9eee9d | how do hydrogen fuel cells create electricity and regulate how much is made? also how is the hydrogen extracted from water and collected? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9eee9d/eli5_how_do_hydrogen_fuel_cells_create/ | {
"a_id": [
"e5ojkj5"
],
"score": [
3
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"text": [
"Hydrogen fuel cells are more akin to batteries in practice. They hold energy by having hydrogen and oxygen separated from one another by a membrane. When the particles travel through this membrane to create water they release a bit of energy into the membrane as electricity. The hydrogen and oxygen are usually initially separated by electrolysis, which is why I described them as effectively batteries."
]
} | [] | [] | [
[]
] |
||
a4a2ap | how can we make an educated guess about the time it is when we wake up without seeing a clock? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a4a2ap/eli5_how_can_we_make_an_educated_guess_about_the/ | {
"a_id": [
"ebcncon"
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"score": [
4
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"text": [
"Light through the window puts you in the ballpark. But also take into consideration the times you’ve been out by a mile.\nI’m a shift worker but on days for a project and after 2 weeks my body now wakes me up 5-10 minutes before the alarm goes off, every flipping day, even on weekends. "
]
} | [] | [] | [
[]
] |
||
5ty232 | what the difference is between x264 and x265 video encoding and which is better | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ty232/eli5what_the_difference_is_between_x264_and_x265/ | {
"a_id": [
"dj6yy5t",
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"text": [
"As of now H264 is the major player around the world. It is everywhere, mobile streaming, youtube, many online sites utilize it. H265 is the successor to H264. H265 was designed to be efficient at video encoding by utilizing about half of the bitrate(kbps), matching and improving on the fidelity of a H264 image. H264 maxed out at 4K/60fps, while H265 maxes out at 8K, has improved image quality, better color space, better dynamic range and supports up to 300fps.\n Even with its advancements in encoding, x265(HEVC/H265) requires more compute power to decode, devices using batteries will run out of power faster(Source) and it is expensive to license. It cost Apple ~$25million for iPhone 6 to use H265 in Facetime(Source). Google has also added decoders to Android 5 and beyond. Windows 10 supports HEVC natively too. The cost will get passed down to consumers especially when it comes to Netflix, Amazon, Hulu, regular tv service. You will probably need a new set top box(DVR) that has hardware decoding capabilities with more muscle than your current one. Remember the encoding efficiency we were just talking about, the sacrifice is compute power. I think all Samsung UHD models have built-in RVU(Receiver box) for DirecTV service, that probably means the quad-core processor that resides inside the display will be doing the heavy lifting. Vizio has a hexa-core inside their UHD sets. Sharp, Sony, LG, Panasonic may also have processors inside to assist in decoding.\n This is what I’ve tried on the different brands in terms of UHD playback. Early Q1 2015, I tried H264 2160p, playback was unsuccessful. H264(2160p) with AC3 audio failed, same for MP3 audio. The sets follow a very strict compliance when it comes to 2160p decoding. The content has to be HEVC(H265/x265) with AAC audio. Samsung displays can play HEVC without audio but throw out an audio error. Vizio, LG, Sharp playback fine even if audio is missing in the content.\n\n_URL_0_",
"The actual encoding is called h.264 and h.265; x264 and x265 are an implementation of that standard.\n\nThe h.264 encoding is older and more widespread. There are a ton of devices that can do h.264 very quickly and/or very energy efficiently. The h.265 encoding is newer and claims to outperform h.264 in many ways, though many devices don't support it (though virtually all PCs, tablets, etc will support both; the devices that won't are very low power, embedded devices and the like).\n\nIn practice both encodings have a *lot* of knobs and dials to play with: you can get a lot of performance out of either, or you can tune either to be absolute garbage. On average, you should expect h.264 to take less processing but to leave you with a bigger file, while h.265 will likely take much more processing to encode, somewhat more processing to decode, and will leave you with a smaller file.\n\nWhich one is better depends on your use. If the goal is to wind up with as small of a file as possible (e.g. if you're trying to archive a bunch of videos on a hard drive with limited space) then h.265 is going to be the way to go. If you're trying to compress videos to watch on your tablet then perhaps consider h.264: the lower processing load means that you'll get a bit better battery life. In most cases expect h.265 to be the better choice; it's the more modern standard, though hardware hasn't quite caught up with it yet. \n\nAs for x264 vs x265, these are software projects that are fairly widely used in programs like FFmpeg or HandBrake. The x265 project is based on the x264 code so they're very similar to one another, though obviously they implement different encoding. The choice between them should be based on h.264 vs h.265, not on the features of x264 vs x265. ",
"The ELI5 answer is that x265 uses better compression, so you can get higher quality with a lower file size. \n\nThe penalty you pay for that is that you need much more computing power to decode it - there's hardly any video hardware that supports it so the CPU has to do all the work. \n\nSo for which is better, that depends on whether you have more CPU power to spare or more diskspace. "
]
} | [] | [] | [
[
"https://www.quora.com/What-is-the-difference-between-x265-x264-video-coding-Which-is-advantageous"
],
[],
[]
] |
||
4rwlsk | When people say stars and nebulae are formed by gas and dust, what exactly is the dust? | I understand that the gas is most likely hydrogen or helium because those are very simple structures. However, when someone refers to dust on earth that is usually specks of dirt (minerals like silica) or organic material (skin cells) which are much more complicated structures. So what exactly is this space dust made of? | askscience | https://www.reddit.com/r/askscience/comments/4rwlsk/when_people_say_stars_and_nebulae_are_formed_by/ | {
"a_id": [
"d54rr3e",
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20
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"text": [
"Carbon compounds and silicates are still around in space, and they can form *very* complex structures. The environments where they form can allow for very different chemistry than is encountered on Earth, even at high vacuum, and the structure and formation of dust remains a large and active topic of research. It also scatters and absorbs light in different ways than gas, so it's important to understand the dust in order to correctly remove its effects when doing all other areas of astronomy. Dust is ubiquitous, causes important effects, and is poorly understood. ",
"I'm 5 years into a PhD on interatellar dust physics, so... Interstellar dust grains are smaller than what you would normally think of as dust on earth. Typical sizes are something like 0.1 microns, but there is evidence for a population of much smaller grains that could be only tens of nanometers in size, basically just a few dozen atoms stuck together. A good picture to have in your head is something like the consistency of cigarette smoke or smog rather than the stuff you wipe off table tops. \n\nComposition is a little tougher to get. There are a few spectral lines that they can tell that dust includes silicon and carbon. Another way of estimating composition is to figure out the relative abundances of elements in stars like the sun, assume the interstellar medium as a whole has the same elements in the same proportions, and then conclude that whatever you don't see in the gas phase spectrosce must be in the solid grains. This would tell you that there are some other elements in dust like magnesium and maybe some iron. So then people try to do things like assume that dust is made of something like olivine (which is a common rock on earth, so why not) and then figure out what mass and volume of dust would there need to be out there if molecules formed in that kind of ratio. Same thing with graphite with the carbonaceous grains, or people try to think about amorphous carbon or amorphous silicon grains, which would just be atoms stuck together without a nice crystal structure. Then if you're a theorist you make predictions about how this type of grain would affect the way starlight gets dimmed or reddened or polarized as it passes through the dust, or if you're an observer you look for these kind of effects to see if you can rule out any models. There's still a lot we don't know."
]
} | [] | [] | [
[],
[]
] |
|
66u04l | When nucleons join together to form a nucleus the total mass is greater than their individual masses (the mass defect). How is the additional mass distributed between each of the nucleons? | I understand that when nucleons join energy is converted to mass. But if an elementary proton or neutron has a fixed mass, where is this new, extra mass located? Is it divided up equally? Does it exist between the nucleons like glue? Or does it just hover randomly around the nucleus? | askscience | https://www.reddit.com/r/askscience/comments/66u04l/when_nucleons_join_together_to_form_a_nucleus_the/ | {
"a_id": [
"dglkgk9"
],
"score": [
15
],
"text": [
"The mass of a bound nucleus is **lower** than the sum of the masses of its constituents, because the nuclear binding energy contributes **negatively** to the mass of the system. That's why the nucleus is bound to begin with, because the state where the nucleons are bound together is lower in energy than the state where they're separated.\n\nThis slight difference in energy is due to nucleon-nucleon interactions, and it isn't \"located\" in any particular place. You can say that the average energy difference for each nucleon is simply the total binding energy divided by the number of nucleons.\n\nBut to calculate particularly the average energy of each nucleon, you'd need to specify a kind of nuclear interaction (there are many), and take individual matrix elements between the various nucleon orbitals.\n\nThere are simpler models like the Fermi gas model, where you can calculate analytically what the average kinetic energy per nucleon is."
]
} | [] | [] | [
[]
] |
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