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eax4lm
|
where does all the food go?
|
Especially if you have a high metabolism where you’re not gaining weight and not pooping an equivalent amount to how much you eat. Where is all this excess food going?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/eax4lm/eli5_where_does_all_the_food_go/
|
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"Poop, heat, and consumed useful energy. You basically take the nutrients, break them down, make energy molecules, release a lot of heat along the way. Then, use this energy to build things like proteins from things you got from food (amino acids). If you're not gaining weight despite eating insane amounts, you either have very high metabolism (genetic, hormonal, age related, aerobic sports, etc) or you have very bad absorption (genetic, some GI disorder, etc) or something is stealing your food (parasite, tapeworm, etc).\n\nEdit: also, please note that the food that goes in is not even remotely similar to the one that leaves (poop). For some things it is but not most. You destroy its architecture, you squish everything into higher density (remove fluid and crush the organization). So if you really want to compare how much food is going out relative to in, you have to measure the mass not volume, and then measure water content because you absorb a lot of that (then water goes out in urine, sweat, breath, saliva, cum, or tears)"
]
}
|
[] |
[] |
[
[]
] |
|
2uyt3g
|
if cellular radio waves are basically everywhere all the time, how do they not get blended with eachother?
|
Same goes for radio stations I guess.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2uyt3g/eli5if_cellular_radio_waves_are_basically/
|
{
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"cocwrve"
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3
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"text": [
"They all have slightly different frequencies, which makes it easier to tell the difference. \nImagine you're trying to pull one thing out of a box while blindfolded. There are three items in the box. Those three things are all apples, but you're trying to get a Granny Smith. The different frequencies would be like taking those same three apples, and coating the Granny Smith in sandpaper. \nMake sense?"
]
}
|
[] |
[] |
[
[]
] |
|
19tjl9
|
How does Antivirus software work?
|
I mean, there are ton of script around. How does antivirus detect if a file is a virus or not?
|
askscience
|
http://www.reddit.com/r/askscience/comments/19tjl9/how_does_antivirus_software_work/
|
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"By checking against a database of known virus signatures, which are a string of bits known to be indicative of a virus or other malicious software.",
"While there are many different styles of viruses and attacks, a lot of antivirus software deployed relies on a currently known threats or vulnerabilities. It is hard to defend against an unknown vector of attack (I use virus here generically), but some basic attacks/detections are as follows:\n\n**Size**\n\nAn easy way to detect if a file has been altered is the size of the file. Some viruses like to tack on their malicious code at the end of the file, and that is a dead giveaway when an antivirus scanner scans it. It compares the before and after sizes, and if there has been no modification by the user, it suspects some malicious activity.\n\n**Pattern Matching** \n\nViruses often have a telltale signature that they use to infect your computer. It could be couple lines of assembly code that overwrite the stack pointer and then jump to a new line of code, it could be a certain series of commands that throw an error in a common application, or it could be using an unchecked overflow or memory leak to grab an exception thrown. Regardless, a lot of infectious software uses an reproducible exploit that is found on the target operating system or application, and those tell tale signs (because they have been spotted before) go into a huge database of known exploits and vulnerabilities. When your antivirus scans through it checks your programs for these malicious activities.\n\n**Detecting Injections**\n\nSince viruses like to use these known exploits, malware writers sometimes like to inject code into pre existing programs, like when you 'accidentally' installed that malicous program. These kinds of attacks typically inject code into dead regions of documents or files, and use a jump to go to the malicious code. To explain further, since blocks of memory are allocated to files, sometimes the very end of the memory block does not get used up, or in some cases, there are certain exploits within certain types of files that have legacy sections that are no longer used. This legacy section is a perfect spot to hide malicious code, since it does not increase the size of your program or file. An injection attack uses the initial startup code to 'jump' to the malicious code, and then 'jump' back, making it seem like nothing was ever wrong, and your program boots up perfectly. There are many many variations of this attack, but an antivirus program typically looks for those strange 'jumps' and code that looks like it doesnt belong in certain sections.\n\n**Hashing**\n\nSome antivirus programs analyze the programs/files byte for byte, and literally compute the sha-1 hash of the item it is detecting. It stores every single hash for everything on your system, and if the program has been modified it will not compute the same hash (that is the whole point of a hash, it changes drastically if only a tiny bit of the program/file changes). This detection is flawed, because if the virus discovers where all the hashes are stored or the algorithm used, it can overwrite the 'secure' hash with the malicious one and the antivirus will never know.\n\n**Deeper Threats**\n\nWhenever you start your computer, or plug an external device into it (hard drive, cd, usb, there are core drivers or 'code' that runs to setup the connections from your computer to the external device. Some viruses exploit this when the connection is being established, and could either execute arbitrary code (instead of the connection code) or can become a man in the middle, where everything acts fine but the virus is actually the one creating the connection, as well as inserting its own code where ever it feels like. Since these threats can work themselves deep within the operating system and core functions, these are extremely hard to detect. If the deeper OS calls are not compromised, like the antivirus calls to the OS, then these attacks can be detected. If the whole system is compromised, then the virus is embedded so deep that you some times have no choice but to wipe it and hopefully do a fresh install. If the code that starts up your operating system is compromised, you have even bigger problems because wiping will not get rid of it.\n\nHopefully this is in layman enough terms for anyone to understand, I didnt rely on any references so please leave a comment correcting me (I will probably be asleep). Hopefully I will wake up tomorrow morning and everyone will understand the basics of computer infections and detections.\n\nEDIT: Thank you for reddit gold, and bestof! My life is now complete!",
"In the old days, it was enough to check if the file contained a certain pattern of bytes - that was the virus' fingerprint.\n\nNowadays, it is way more complicated. Virus detection programs still do that, of course, but they also watch for suspicious behaviour, like a program trying to replace certain files, or trying to connect to known-bad websites without your permission.\n\nVirus descriptions have become more like programs themselves, than just simple patterns. These are also updated frequently, from a master database that the antivirus software company keeps.\n\nVirus researchers tell each other about new viruses, and researchers at each major company or institute study the virus until they can understand it enough to write a new description for it.\n\nHere is an example of a discovery report for a virus:\n_URL_0_\n\nAnd here's Symantec's \"threat center\":\n_URL_1_",
"I asked this exact same question a week ago with not much response, hopefully you get more answers here!\n\n_URL_0_",
"Kind of off topic, but what are some of the worst viruses out there?",
"Pattern matching, but increasingly they don't work well at all. Instead defense is becoming much more proactive (firewalls, sandboxes, walled gardens). ",
"Nobody has mentioned an important term yet: \"Heuristic\". Often combined with so called \"on access\" or \"realtime\" scans the antivirus program keeps track of all files on the computer and automatically scans new files or whenever a file is accessed by the operating system anyway. Besides searching for patterns that belong to already known viruses it tries to guess what the file will do when executed. That guesswork is not very reliable. You can see that quite often for legitimate mods for games that do certain things to inject itself into the game that is perhaps similar to what viruses do. But frequently you see some overly eager heuristics slipping through \"quality control\". Some examples are on that wikipedia page: _URL_0_",
"Software developer for an antivirus company here. While I don't work on the actual scanning engines, I think I can provide some insight on how your computer is protected.\n\nThe first barrier is the operating system:\n\n* **[UAC](_URL_1_)** (starting with Windows Vista); I know few people keep it on but it *does* prevent software from messing with your system files and registry without your consent. Please keep in mind that a clever enough piece of software, given administrator rights can do a lot of damage even if you have an antivirus installed;\n\n* **[Code signing](_URL_0_)** (this includes the size/hash described by our fellow redditor) - a signed file is of controlled origin and therefore most likely safe; any changes to the file would cause it to fail its signature check and would raise questions.\n\n* **Driver signing** - starting with Windows Vista, all drivers must be digitally signed or the operating system will refuse to load them (there are ways to circumvent this for development purposes but I doubt it can be done automatically by a virus without anyone noticing).\n\nThen the actual antivirus picks up:\n\n* **Virus signatures** have been covered to a certain extent (here's an [example](_URL_2_), though) - some viruses work by replicating their working code but unless it changes in time they can be identified by tell-tale segments of code;\n\n* **Heuristics** (a.k.a. \"suspicious behaviour\") - there are certain activity patterns that can indicate malicious intent (like repeatedly overwriting the registry key to automatically start with Windows or trying to mess with your computer's system files, booting process or the antivirus itself);\n\n* **Cloud scanning** is a rather new concept - it involves checking suspected files to see if they're common on users' computers, whether someone has reported them as malicious etc; more about this below.\n\nOther information:\n\n* File cache - commonly used files (especially system files) are cached after they're scanned and considered \"safe\" until any changes are made to them;\n\n* Level of suspicion - files aren't either \"safe\" or \"viruses\", according to the internal logic of the various principles (and engines) they are given a ranking; if a file is considered a possible threat by one scanning engine (e.g. the cloud scanner) there is no cause for alarm but it will most likely be scanned by a more thorough engine like the signature scanner;\n\n* Quarantine - files that are \"almost sure it's a threat\" end up locked down and prevented from being run/accessed; this process is usually reversible by the user (sadly, some false-positives do occur);\n\n* Analysis - files sometimes are willingly sent by concerned users to be analysed by the experts; this helps a lot and usually there's an update ready in a few hours after a new virus hits the market;\n\n* Inability to perform a clean/delete on a file - modern AV solutions usually try to gain exclusive access to the file system and might be able to deny access, disinfect and/or delete a file that you yourself couldn't manually. Even so, some files (most likely core system files or drivers) can't be operated on, but various workarounds can be attempted."
]
}
|
[] |
[] |
[
[],
[],
[
"http://www.cert.org/incident_notes/IN-99-03.html",
"http://www.symantec.com/security_response/"
],
[
"http://www.reddit.com/r/AskReddit/comments/19d8gr/how_does_antivirus_software_work/"
],
[],
[],
[
"http://en.wikipedia.org/wiki/Antivirus_software#Problems_caused_by_false_positives"
],
[
"http://en.wikipedia.org/wiki/Code_signing",
"http://en.wikipedia.org/wiki/User_Account_Control",
"http://www.nlnetlabs.nl/downloads/antivirus/antivirus/virussignatures.strings"
]
] |
|
2fd9va
|
how did we come to understand universal symbols for play, rewind, fast forward, and so on. what is the design of these symbols called?
|
Something I was thinking about recently is how a lot of devices like remotes, control panels, etc, all have these symbols that are shorthand for the function they perform.
Examples: _URL_0_
Like, 'star' has become pretty standard for favorite something, a heart/thumbs up is a like, and so on.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2fd9va/eli5_how_did_we_come_to_understand_universal/
|
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"text": [
"They become ICONS by means of a general CONSENSUS as to what they mean.",
"We all understand them because culturally we've been conditioned to know that a thumbs up means \"good/like\", a heart means \"favorite\", two right-facing arrows means \"faster\", etc. A baby has no idea what each symbol means; it's something we learn as we grow up. It's something we learn very early though, judging by how quickly my baby cousins have mastered Netflix.\n\nThe study of symbols is called semiotics.",
"[No one is really sure](_URL_0_), but the pause icon resembles the symbol for a break in electronic schematics, and the play symbol seems to imply forward motion. "
]
}
|
[] |
[
"http://cache4.asset-cache.net/xc/466037403.jpg?v=1&c=IWSAsset&k=2&d=B53F616F4B95E5538F961FB2DF43F838F6C0FB6433A47A7438F76B61711082D1"
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[
[],
[],
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"http://imgur.com/gallery/Lp0hn"
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|
88g8jl
|
what is bicarbonate?
|
I am learning about the means of transport of carbon dioxide in my college A & P II class right now and I learned that 70% of CO2 is transported as bicarbonate dissolved in plasma. The only chemistry background I have is junior year high school chem, so I’m very confused about what bicarbonate is, especially in relation to anatomy.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/88g8jl/eli5_what_is_bicarbonate/
|
{
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"dwkg7dc"
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3
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"text": [
"Bicarbonate is HCO3(-). It acts as a buffer keeping your blood within certain pH values. \n\nIt is formed when H2O and CO2 are combined in red bllod cells by carbonic anhydrase(an enzyme) to make carbonic acid, H2CO3. This carbonic acid quickly breaks down into H and HCO3. When it reaches the lungs the bicarbonate is separated back into H2O and CO2."
]
}
|
[] |
[] |
[
[]
] |
|
7jju3e
|
When did Sunzi's "The Art of War" become popular in the West?
|
Furthermore, was Machiavelli's [book by the same name](_URL_0_) intentionally titled the same as Sunzi's masterpiece?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/7jju3e/when_did_sunzis_the_art_of_war_become_popular_in/
|
{
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"dr70eva"
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"text": [
"It's a late 20th century phenomenon. The book was not translated into any European language until French in the late 18th century and wasn't completely translated into English until 1910 by Lionel Giles (as _Sun Tzu on the Art of War_). Machiavelli was certainly unaware of it. Also, the Chinese characters \"兵法\" are more literally \"warfare\" + \"rules/method\", so if anything it'd probably be more likely Machiavelli's work influenced the English title either directly or just by helping establish 'art of war' as an idiom in English.\n\nAnyway, [here's a telling statistic, courtesy of Google books](_URL_1_) on the frequency of \"Sun-Tzu\" in English publications. There's a small peak during World War II, where an increased interest in military strategy would seem self-explanatory (not least since China was at war). Interest seems to die down after the war and then there's a dramatic rise starting in 1964 and continuing to present day. This would coincide with the 1963 publication of [Griffith](_URL_0_)'s translation, which is also the first one titled simply _The Art of War_. Griffith's translation included more biography and commentary, but it doesn't seem too speculative to imagine that Griffith's status as an American general and war veteran also helped it garner more attention.\n"
]
}
|
[] |
[
"https://en.wikipedia.org/wiki/The_Art_of_War_\\(Machiavelli\\)"
] |
[
[
"https://en.wikipedia.org/wiki/Samuel_B._Griffith",
"https://i.imgur.com/jdlotUa.png"
]
] |
|
23kq8x
|
During WWII, what was Stalin's plans for if the Germany army captured Moscow?
|
Would they have moved their administration/capital to the East? In the event of Moscow's fall, what would Germany have done: continued into Siberia or negotiated a peace treaty?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/23kq8x/during_wwii_what_was_stalins_plans_for_if_the/
|
{
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"In October 1941 the Soviets began seriously discussing the possibility of Moscow falling. Stalin decided that he was going to stay in the capital. It was feared that seeing Josef Stalin and the government flee would cause a massive panic among the cities massive population. There was also an idea of burning Moscow similar to what the Russians had done to Napoleon. But Stalin saw that when Moscow was burned in 1812 it was little more than a small town, the Moscow of 1941 was a vast, sprawling modern city. \n\nStalin also used this new boost of energy to begin taking control of the situation. The new stet defence committee began to make preparations for defending against the Germans, and on October 10th, stalin appointed Georgia Zhukov to defend the capital. Stalin said that there would be \"no evacuation\" and than he said that \"We'll stay here until victory\". \n\nEven with Stalin's assurances some sectors of the city began to delve into panic and mass hysteria. However Zhukov got a handle on the situation and declared martial law. He had over a million men to defend the city. It was assumed that the Germans would try and encircle the city, so a massive amount of conscript troops were placed behind the city on the Volga river, Stalin as Zhukov both hoped this would stop the encircle men of the city. \n\nIn all likely hood had it looked like the Germans were going to take Moscow, the majority of the soviet government would have probably fled east and continued the fight. Stalin might have as well. But the prospects looked good for the soviets, they had a superior amount of men, equipment, and were equipped for winter fighting. Stalin had no reason to panic. "
]
}
|
[] |
[] |
[
[]
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|
7y5jd5
|
If I were a sexually active gay man in early 19th century England that never actually broke the anti-sodomy laws how open could I be?
|
I was reading recently about a missionary that was sacked over allegations of homosexual activity, and was kind of surprised to learn that nothing he was alleged to have done was actually illegal at the time. My questions are, if you weren't actually breaking the law could you still get in trouble? How and from who? Could you be pretty much open about it?
Secondary question: in what situations were people actually prosecuted for sodomy? It seems like a difficult crime to get convictions for.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/7y5jd5/if_i_were_a_sexually_active_gay_man_in_early_19th/
|
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"This question got me curious: what does it mean to be sexual active but not violate the anti-sodomy laws on the books? The following answer is not from a deep font of knowledge, but is merely what I have gathered through my own curiosity this evening.\n\nThroughout the 19th century there were three acts that outlawed \"buggery\" and/or \"sodomy\": the Buggery Act of 1533, which was replaced by the Offenses Against the Person Act of 1828, which was replaced by the Offences against the Person Act of 1861.\n\nNone of them were particularly clear with what they were outlawing. The Offenses Against the Person Act of 1828 is the pithiest, so I'll quote the relevant section in full here:\n\n > Sodomy.\n\n > XV. And be it enacted, That every Person convicted of the abominable Crime of Buggery, committed either with Mankind or with any Animal, shall suffer Death as a Felon.\n\nAs you can see, the act does not define buggery or sodomy (neither of the other acts do, either), and all later works I've found seems to assume buggery and sodomy are to be treated as synonyms. In common law systems, the courts set binding precedents for what the law actually means in ambiguous cases.\n\nIn 1817, the case *Rex v. Jacobs* set out to exactly what sorts of \"unnatural acts\" are included under buggery/sodomy. I found the full decision quoted in a Montana Supreme Court decision, *State v. Dietz*, and I'll warn you, it's disturbing and the victim is a seven year old child. Here's the decision:\n\n > Rex v. Samuel Jacobs.\n\n > The prisoner forced open a child's mouth and put in his private parts, and proceeded to a completion of his lust. Held, that this did not constitute the offence of sodomy.\n\n > The prisoner was tried and convicted before the Lord Chief Baron Richards, at the Warwick Lent assizes, in the [\\*332] year 1817, upon an indictment for sodomy, \\*556 committed on James Thompson (a boy of about seven years of age,) on the 8th of March, 1817.\n\n > It was proved very satisfactorily, that the prisoner had prevailed upon the child to go with him from the market place in Nun-Eaton to a rick yard in a field near the town; that he forced the boy's mouth open with his fingers, and put his private parts into the boy's mouth, and emitted in his mouth.\n\n > The question was whether this was sodomy.\n\n > In Easter term, 1817, the judges met, and were of opinion that this did not constitute the offence of sodomy, and directed a pardon to be applied for.\n\nWhat does this mean? That in the initial ruling, oral rape of a child was ruled sodomy in 1817 but this initial ruling was overruled upon appeal. The *Dietz* decision uses the term \"per annum\" a lot, and it seems from that understanding that in English Common Law in the 19th century, buggery and sodom both meant anal sex not oral sex. As some 19th century legal dictionaries (quoted in the *Dietz* opinion), \n\n > At common law, sodomy, was committed only by penetration per annum; penetration per os did not constitute the crime.\n\nAnd\n\n > Sodomy consists of sexual connection with any brute animal, or in sexual connection, per anum, by a man, with any man or woman. The act committed in a child's mouth is not enough.\n\nSome are slightly more demure and do not say where sodomy *is* committed, but where it isn't:\n\n > To constitute this offense, the act must be in that part where sodomy is usually committed. The act in a child's mouth does not constitute the offense.\n\nThe *Dietz* opinion quotes a *lot* of these legal dictionaries (before moving onto medical dictionaries, which hold the same), all based on the *Rex v. Jacobs* opinion. You can read the full opinion [here](_URL_0_). \n\nIt's worth noting that this seems to be a reversal of the 18th-century standards, where oral sex does appear to be included in some sodomy convictions.\n\nAs a side note, U.S. law in the 19th century apparently largely followed the 1817 precedent, which is why I was able to find the full text of the option in *Dietz*. For example, when the Portland Vice Scandal of 1913 happened, the state of Oregon responded by clarifying the law and specifically including fellatio (*per os*) in the new law. Some other states also changed their laws regarding sodomy or created new laws (contributing to the delinquency of a minor, committing lewd and lascivious acts, etc.) which also covered oral sex. \n\nIn the U.K., this sort of amendment, broadening criminal homosexual acts beyond \"buggery\", happened slightly earlier, in 1885, when Labouchere Amendment to Criminal Law Amendment Act of 1885 was passed. That section reads:\n\n > Any male person who, in public or private, commits, or is a party to the commission of, or procures, or attempts to procure the commission by any male person of, any act of gross indecency with an other male person, shall be guilty of a misdemeanour, and being convicted thereof, shall be liable at the discretion of the Court to be imprisoned for any term not exceeding two years, with or without hard labour.\n\nNow, again, \"gross indecency\" is no more defined in statute than \"buggery\" or \"sodomy\" had been (definition would likely have been too yucky), but it was clearly meant to cover homosexual relations that fell short of legal sodomy *per anum*. This is ultimately the Act that Alan Turing, Oscar Wilde, and the men prosecuted from the Cleveland Street Raid were charged under.\n\nNow, I only looked into this because I was surprised that homosexual oral sex wasn't covered by early 19th century anti-sodomy laws, but I can't find anything that indicates to me that oral sex, mutual masturbation, and other similar homosexual acts were explicitly illegal in England between 1817 and 1885. However, it is clear that they would put one in a marginalized, scandalizing community, and I think Wilde's case (among others) shows that to be convicted of such an offense (and probably even just accused) was to suffer tremendous social opprobrium not entirely tied up with mere matters of the law. Though his trial was after the 1885 making gross indecency illegal, and not requiring buggery, it gives I think a sense of the social climate that would have existed even before the change. \n\nAs you'll see below, gay men were frequent victims of blackmail, especially after 1885. \n\n(Continued below with a discussion of the records we have from the Old Bailey Court in London)",
"In response to the secondary question:\n\nSearch of the proceedings of the [Old Bailey 1801-1850](_URL_0_) shows 140 indictments for criminal sodomy during the period, with 76 convictions.\n\nPrior to 1834 *all* found guilty were sentenced to death by hanging. After 1848 none were (despite it being a capital crime until 1861).\n\nThe last death sentence executed was in 1835. Thereafter, mostly half-year, a year, two-year sentences.\n\n > in what situations were people actually prosecuted for sodomy? It seems like a difficult crime to get convictions for.\n\nThe last men executed, James Pratt and John Smith (1835) were *literally* convicted due to \"nosy neighbors looking through a keyhole.\" There's really no alternative to eyewitness testimony--only whether observers caught the accused *in flagrante* or were themselves complicit.\n\nSo we need to separate this question. It's not so difficult to convict (after all, +50% guilty for all indictments) but difficult to indict.\n\nThose 140 case over 50 years often (and naturally) involve two defendants. It's more like two cases prosecuted *per annum.* Population increase in the jurisdiction is +100% in the timeframe. The population profile tends young, and (of course) all potential criminals are male. Figure the yearly indictment rate is, very broadly, on the order of one-in-a-quarter-million potential sodomites.\n\nSo, yeah, difficult to *indict* because the only evidence is a witness. Discussion of societal norms of who would testify against a defendant, given the potential death sentence involved in doing so (and how this changed given the reduction in potential sentences) is beyond what I'd dare here.\n\nFUN FACT: Thought this is outside the era you define, in the *(in)famous* Boulton & Parks case (1870) the police medical examiner decided to examine the arrested for evidence of sodomy, and reported that he found such evidence. But his self-appointed proctological investigations proved a disaster for the prosecution.\n\nI'm not aware of any CSI-type evidence being presented before that date."
]
}
|
[] |
[] |
[
[
"https://law.justia.com/cases/montana/supreme-court/1959/343-p-2d-539.html"
],
[
"https://www.oldbaileyonline.org/"
]
] |
|
1hxcls
|
what happens to prices/wages when a country implements euro as the currency?
|
I have friends in a country that is not in the eurozone yet, but there is talk of adopting euro as the currency. What would that mean in terms of prices? Even if the current food/domestic products prices may be way below the average EU price, I do not expect everything to stay at the same level. Will that mean people will earn more in comparison to before when the pay is 'translated' to euros? Will the prices go up? Will the prices remain the same, just in a different currency?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1hxcls/eli5_what_happens_to_priceswages_when_a_country/
|
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"text": [
"In theory (and largely in practice) prices and wages will stay the same, just in a different currency.\n\nYou're correct in your implication that this means that goods and services can vary widely in price across the eurozone.",
"If a country joins the Eurozone, their old currency is fixed to the Euro.\n\nSo, if you had a price in German Marks, you had to divide it by 1,95583 to get the same price in Euro. And that will never change. If I go and check under the couch and find old German Marks, I can still get them exchanged for that precise course.\n\nOne Mark *is* 0.51129188119 _URL_0_ difference, no change. They represent the same value.\n\nSo, if you have a job that pays a certain amount of money, it will simply be paid in the equivalent number of Euros after that.\n\n > Will the prices go up?\n\nThey will change. But that has nothing - or little - to do with things now being paid with different coins that have different numbers. It has everything to do with a new country joining a larger commercial union.",
"See where the money and the people are going.\n\nSay you run your country with your own currency. You get to set interest rates, and if your country slows down, you can lend money at a cheaper rate. The downside is that your currency may be cheap today and dear tomorrow, and people in other countries may not want to do business with you.\n\nSo you sign up to the Euro. Now this is not a peg, but a complete conversion of your old currency to the euro. You don't have the tools to change the value of your currency anymore - a euro costs a euro anywhere in the zone, and its value relative to the world's monies is set by the European Bank. Things that are cheap in your country now gets sold far and wide, whereas things that are expensive in your country gets replaced by imports.\n\nBut what if your country's economy slows down? Sorry, we're all in it together now, says Angela Merkel. If the whole of Europe were a real country, the rich part may help the poor part by transferring tax revenues until both get better in a new and stabler setting. But this is just the Eurozone, so you have to sit it out until your country recovers on its own. You can spend what you have in your piggy bank, but if you go bust nobody's going to want to take care of you. (Unless your tiny little country manage to sink the euro with it, that is. Then you become Greek.)\n\nNow, on to the flow of people. After eurozone comes Schengen Zone, guaranteeing the flow of people. And people follow the money, and the mobile people in your country will go abroad. Foreign Europeans will want to come to your pristine country and do serious business as well, so there is an exchange of labourers for investors.\n\nAny questions?"
]
}
|
[] |
[] |
[
[],
[
"Euro.no"
],
[]
] |
|
356zk7
|
Why do war memorials in Britain commemorate World War I as 1914 to 1919
|
I have noticed this at memorials all over Britain. Why don't they say 1914 - 1918?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/356zk7/why_do_war_memorials_in_britain_commemorate_world/
|
{
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"cr1ks87"
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38
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"text": [
"World War I technically ended in 1919.\n\nGermany signed an armistice with the Allies in November 1918 which marked only the end of actual fighting, but not the war itself. The war is considered still ongoing until the terms of surrender are formalized and signed. That occurred in 1919 during the Paris Peace Conference which resulted in the Treaty of Versailles."
]
}
|
[] |
[] |
[
[]
] |
|
10g9gu
|
how can an animal eat its own kind with no side effects but human cannibalism causes brain damage?
|
Deep down we're all 'animals'.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/10g9gu/how_can_an_animal_eat_its_own_kind_with_no_side/
|
{
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"text": [
"Animals can't either; look up mad cow disease.",
"It isn't the human flesh that causes brain damage, it is the risk of parasites/prions in the human flesh. Thoroughly cooked human flesh won't hurt you, but if it is under cooked or you eat infected brain matter (as with the cows who got mad-cow disease) then you are at risk.\n\nGenerally you only find cannibalism in less developed areas and so the risk is greater.",
"related; are humans even safe to eat aside from things like vitamin A and diseases? Like, wouldn't toxin buildup from us being at the top of the food chain be too much to handle? I've read that large animals such as whales are actually declaired biohazards when they are found dead on the shore due to mercury, etc. ",
"OK, prions are a problem. But I'm healthy (I think) so if my doppleganger (assuming basically the same genetic structure to over simplify things) were to eat me, would he get sick? When exactly does it become a problem? Does having the prions in you make you sick, or ingesting them from another source make you sick?",
"Cannibalism is dangerous because all the things that are capable of harming you are most prevalent in your own species. It's no worse for humans than it is for animals."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[]
] |
|
2ne6oo
|
What decides which plate subducts in ocean-ocean convergent plate boundaries?
|
And another quick question: continent-continent plate boundaries don't see any subduction because both of the plates are less dense than the asthenosphere, right?
|
askscience
|
http://www.reddit.com/r/askscience/comments/2ne6oo/what_decides_which_plate_subducts_in_oceanocean/
|
{
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"cmcy1a7"
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"score": [
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"text": [
"For the ocean-ocean case, basically the age of the plates. Age is essentially a proxy for temperature/thickness. Imagine tracking a piece of oceanic crust from its formation point at a mid-ocean ridge. As it moves away from the ridge, it cools and thickens, increasing the aggregate density of the plate at that point (or distance from the ridge axis). Where two oceanic plates meet, the prediction would then be that the older (denser) plate will subduct. \n\nFor the second part of your question, yes, generally, continental crust is not subducted because it is too bouyant with respect to either the mantle or oceanic crust. It is important to remember that most continent-continent collisions are preceded by subduction of an oceanic plate beneath a continental margin and that the \"collision\" occurs when this ocean basin has been completely subducted. This is important because depending on the details (rates of subduction, size of the slab, nature of the continental crust, etc) the \"pull force\" can be enough to suck some amount of continental crust down. This is often referred to as \"continental subduction\" and is likely an important process for forming particularly weird bodies of rocks we see in mountain ranges called either \"UHP\" or \"HP\" terranes, which stand for either ultra high pressure or high pressure terranes, respectively. These are basically blocks of continental crust that were drug down quite deep, experienced a fair bit of metamorphism and then rather quickly made it back to the surface. That last bit, how they make it back to the surface, remains an interesting question in tectonics.\n\nEDIT: Meant to add that if you have access to a library or can find a copy of it somewhere, \"Cloos, M., 1993, Lithospheric buoyancy and collisional orogenesis: Subduction of oceanic plateaus, continental margins, island arcs, spreading ridges, and seamounts, Geological Society of America Bulletin, v. 105, p. 715-737\" is a classic treatment of this problem/question."
]
}
|
[] |
[] |
[
[]
] |
|
f4gvat
|
why are people born with photographic memories? how does this impact psychological childhood development?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/f4gvat/eli5_why_are_people_born_with_photographic/
|
{
"a_id": [
"fhqq12i"
],
"score": [
4
],
"text": [
"Photographic memory is a myth. Not a single case of it has even been found, so no one is born with it. Makes for great TV though. \n\n\nThere is such a thing as Eidetic memory, but only really found in children, disappears as they get older, and even this is often warped or flawed in some ways. \n\n\nThere is no such thing as perfect memory. A very few adults have unusual memories, but those usually come with some pretty severe mental problems in other areas instead."
]
}
|
[] |
[] |
[
[]
] |
||
1w1syl
|
Speed differences for loading content from Discs, Hard-Drives and Solid State Drives(SSD)
|
Eg., running Crash Team Racing. Would it load quicker on an original PS1 or as a ROM on a PS1 emulator saved to a HDD/SDD on a PC? What speed differences would there be?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1w1syl/speed_differences_for_loading_content_from_discs/
|
{
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"cexzijp",
"cey0ew4"
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2
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"text": [
"It might load quicker from an HDD/SDD. \n\nI'm not sure about PS1 emulators but some emulators (sometimes only on some roms) need to slow down reading from HDDs to match the loading speed of the original drive as loading at a higher speed can throw off the game timing and cause glitchs or crashes.\n\nThis can even happen when not emulating, Apparently, there is at least 1 game on the PS3 that crashes when loading from HDD instead of from the disk drive due to the faster loading speed (of course to do this you need a hacked unit so that could be a factor)\n ",
"I'm not sure about what emulator you're using, but it would most likely load faster on the PC and here's why:\n\n1. Newer Processor/RAM/Motherboard/etc. (since we're in 2014)\n2. (the question you were asking) Since Discs and HDD have to spin, there is a significant speed difference between each version of memory (CD < HDD < SSD). To make it really basic, the faster it spins, the faster it can read the information and the faster it can read the information, the faster the game can play (unless it is read into memory).\n\nOverall, I would say that you wouldn't see too much of a difference because Playstation games are created with the hardware in mind and most games nowadays load the important things into RAM and try not to access disc resources that are time-intensive.\n\nLet me know if that makes sense."
]
}
|
[] |
[] |
[
[],
[]
] |
|
477hup
|
how were the first construction cranes built when there were no other cranes to reach or lift the heavy weights?
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/477hup/eli5_how_were_the_first_construction_cranes_built/
|
{
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"text": [
"Cranes can construct themselves. You dont need a crane to build a crane. Its tricky but it can be done.\n\nYou could also easily build a crane by constructing scaffolding around it and putting it together that way.",
"We've had simple cranes being built thousands of years in the past, so putting together a small crane isn't an insurmountable task. Besides, you don't necessarily need a crane to put together another crane, as long as you've got something like a ledge to work with, or even a pulley system mounted to a higher point, like a building.",
"Gin poles were used for a long time. I haven't worked with them myself, but the previous generations of my trade could lift nearly anything with them. \n\n_URL_0_\n"
]
}
|
[] |
[] |
[
[],
[],
[
"https://en.m.wikipedia.org/wiki/Gin_pole"
]
] |
|
ehh4n9
|
how it is determined that people who died while texting-and-driving were actually looking at their phone at the time of (or time leading to) impact?
|
I always wonder how it is determined that people who died while texting-and-driving were actually looking at their phones at the time of (or time leading to) impact. I feel like it’s a pretty serious accusation to make - as it, in a way, provides a rationale for their death.
I should clarify that I’m the most anti-texting and driving person you’d ever meet.
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/ehh4n9/eli5_how_it_is_determined_that_people_who_died/
|
{
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"text": [
"No way to know accurately. But some estimates based on witnesses that saw the driver texting. Seeing sent text messages with that time stamp, etc. In general cellphone in hand at the time of accident could be classified as driving and texting regardless of actual use.",
"Txt messages all have timestamps recorded on the phone and also on the telco side. You can match up the timestamps with the accident.\n\nA lot of accidents also have witnesses and it's really obvious when someone is using their phone while driving.",
"If the deploying airbag embeds the phone into the drivers cranium, then that’s a good indicator too.",
"One way is to look at the text box where you type in the meassage, and see if there's an incomplete word or sentance at the end."
]
}
|
[] |
[] |
[
[],
[],
[],
[]
] |
|
9w800e
|
Did the ancient Arabs, such as the Qedarites, self-identify with the Biblical genealogy of the Arabs, i.e. Ishmaelites?
|
Genesis 16:12 has Ishmael described as 'a wild ass of a man' so I think that it would be unlikely that the Arabs would identify with the character. Is there any evidence of the ancient Arabs calling themselves Ishmaelites?
I am also skeptical of Islamic genealogies of the Arabs, because they were compiled retroactively in order to justify the legitimacy of Arabs as legitimate inheritors of the Abrahamic tradition. (In short, I think they are apologetic rather than historical.)
I would be grateful if anyone has any literature on this as well.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/9w800e/did_the_ancient_arabs_such_as_the_qedarites/
|
{
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"text": [
" > Is there any evidence of the ancient Arabs calling themselves Ishmaelites?\n\nThe term *Ishmaelites* appears mostly in non-Arabic sources. While a genealogical link between the Arabs and Ishmael appears in numerous Arabic sources, Arabs nonetheless did not use that term (the Arabic equivalent of the term, *Ishmaelites*, is often used to refer to a specific group within Shi'ism).\n\n\n > Genesis 16:12 has Ishmael described as 'a wild ass of a man' so I think that it would be unlikely that the Arabs would identify with the character.\n\nWe should not assume that any link between the Arabs and Ishmael was made to fit that description particularly. That's to say, when the Arabs were identified/self-identified as Ishmael's descendants, this identity was not necessarily made in light of the biblical view. This should especially be taken into account when approaching Arabic sources. For example, the Qur'anic account of Ishmael is very positive. Ishmael is portrayed as a patient, obedient and helpful son, an exemplar father-son relationship.\n\nThe earliest surviving source to link the Arabs with Ishmael is a second-century BCE work ascribed to Artapanus (of Alexandria). Speaking of the Arabs, he wrote:\n\n > The kings of the Arabs were the descendants of Ishmael, the son of Abraham and the brother of Isaac.\n\n The first Arabic source is the Qur'an. A passage from Q 22:78 reads (translation by M. Abdel Haleem): \n\n > He has chosen you and placed no hardship in your religion, the faith of your forefather Abraham.\n\n\n\n**EDIT**: I forgot to mention this: we should distinguish between two terms here, *Arabs* and *Arabians*. Arabs are Arabian, but Arabians are not necessarily Arab. The different groups of Arabia are called *Arabian*, among them one group is known as *Arabs*. A term used by the group itself. Arabic sources speak of the Arabs specifically as Ishmaelite, not the Arabian groups in general. For example, Ibn al-Kalbī (d. 819 CE) in his writings about genealogy links some Arabian groups to the biblical Joktan (Yaqṭān). \n\n"
]
}
|
[] |
[] |
[
[]
] |
|
1aukj8
|
how does my hair get tangled so quickly?
|
I swear it takes all of 10 minutes for tangles to appear in my hair.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1aukj8/eli5_how_does_my_hair_get_tangled_so_quickly/
|
{
"a_id": [
"c90y1vc"
],
"score": [
3
],
"text": [
"Entropy. There are more ways for your hair to be tangled, than untangled. "
]
}
|
[] |
[] |
[
[]
] |
|
rcbek
|
why do i look up and the right when i'm trying to remember something?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/rcbek/eli5_why_do_i_look_up_and_the_right_when_im/
|
{
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"c44ncoo",
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],
"text": [
"I look to the side, personally; I think looking in another direction helps you focus on something different quicker.",
"It's a microexpression. You're looking away as your brain tries to find the memory. \n\nPolice sometimes as you a random question to establish a baseline to refer back to. Your eyes might drift to the side as you recall a memory. \n\nLater, when they ask you where you were the night Bobby was murdered, if your eyes drift the same way, they know you're probably telling the truth. If you answer head-on without that glance, your brain's probably making things up because you didn't do that recall glance. "
]
}
|
[] |
[] |
[
[],
[]
] |
||
3niee0
|
It was common for upper-class European women prior to the contemporary era to occupy themselves with pursuits in music and art as a matter of enriching home-life. Do we know of any outstanding talents among them?
|
This is generally a class of women who did not have much in the way of public life or personal notoriety, and would likely have shied away from widespread acclaim as a matter of propriety -- but surely among an entire class of women whose role (after babies) was to delight and entertain, there had to be some that were truly gifted?
Do we know of any upper-class women who were favorably compared to notable professional artists or musicians? Are there any intact collections of work? Are there any who became notable posthumously?
(I don't normally exclude literature from "the arts," but for the purpose of this question, I'm already familiar with upper-class women authors and anonymous publishing. I'd be curious to know about any anonymous art-displays though.)
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3niee0/it_was_common_for_upperclass_european_women_prior/
|
{
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"Are you looking exclusively for married upper class women who took a hobby of music and became famous for it, or just if there are famous female musicians prior to the modern era?",
"Mary Casssatt was an outstanding female artist. However, there are some caveats to this suggestion. 1) She was born in Pennsylvania in 1844, moved to Paris in 1866 and spent most of her adult life living in western Europe. 2) Mary Cassatt never married or had children, although she did have a long term love-hate relationship with Edgar Degas. 3) She died in 1926, so she might be to recent for the time limits of your question. \n Cassatt and Degas were leading members of the Impressionist Movement in late nineteenth century Paris and often held joint art shows at important art galleries. They were neighbors in Paris, but they argued about politics constantly. Edgar Degas was also a male chauvinist pig, who was famously quoted as saying \"No woman has the right to draw like that\", when he was commented on some of Mary Cassatt's paintings. \n Mary Cassatt was a prolific artist. Indeed, she made it her profession and supported herself by selling her paintings. Her father was an upper middle class stock broker, but he would never send her any money, while she lived in Paris. Mary Cassatt's younger brother, Alexander, was the president of the Pennsylvania Railroad and was one of the wealthiest men in the United States, during the Gilded Age. Alexander would never directly subsidize his older sister, but did open the door for her to sell many paintings to the plutocrats in the United States. Many Mary Cassatt paintings have found their way into important art museums around the world. An important collection of her work was presented in the retrospective show \"Mary Cassatt: Friends and Family\" in 2008. Nancy Mowell Mathews was the curator of that show and wrote the companion coffee table book that has color illustrations of the paintings in that show. Nancy Mowell Mathews also wrote a good biography about the artist in 1994 \"Mary Cassatt: A Life\" ",
" > there had to be some that were truly gifted?\n\nCertainly.\n\n**Amy Marcy Cheney Beach (1867-1944)** was a composer and pianist. She was born into a very well doing family, a child prodigy who started composing at around 5 and started giving recitals at 8. She had formal musical instruction for a while, but was mostly self-taught, and became a professional musician for a few years. That is, until she married in 1885. She agreed to limit her performances and to donate the profits to some charities. Why? Because being a professional musician was not a proper thing for a married woman (as you mentioned, propriety and what not)... She almost exclusively focused on composition after that (something she could do while staying at home like a decent married woman). When her husband died, she went to give some concerts in Europe .\n\n[Here's her piano concerto](_URL_4_). Not something you would imagine was composed, or played, by a rich stay at home wife. \n\n**Fanny Hensel née Mendelssohn Bartholdy (1805-1847)** was also born into a prominent family. She, and her little brother Felix (yes, THE famous Felix Mendelssohn), received a musical education early on. She showed great ability, and contemporary musical super stars found her to be amazing. There had been women in her family who were active lovers and supporters of music, and some were also skilled players. Her father was not very supportive, and openly told her music could be her brother's profession, but for her it could only be a hobby. Felix thought publishing her music under her name would upset her womanly duties. She got married, and her husband was OK with having her music played at family concerts.\n\n[Here's a trio by her](_URL_2_). I find it pretty damn good.\n\n**Anna Amalia of Prussia (1723 – 1787)**. She was the daughter of Frederick William I of Prussia and sister of Frederick II, it's hard to get any posher than that. Her father mistreated her and was completely against any formal musical instruction for her. She only managed to seriously study after his death. Her teacher was J. P. Kirnberger, who was a student of J. S. Bach. She became known as a patron of music, and a serious composer. She preserved a lot of music by Bach, Handel, Telemann, and others. She knew what she was preserving, it was apparently not just a hobby and she was not just collecting old music.\n\n[Here's a flute sonata](_URL_8_). A nice work in the style of her time.\n\n**Maria Antonia Walpurgis Symphorosa (1724 – 1780)**. Her Serene Highness Maria Antonia, Princess of Bavaria, Duchess of Bavaria, was educated in the arts. She was a singer, harpsichordist and composer, also a patron of the arts with a refined taste. She studied under Porpora and Hasse (who were top notch musicians in their time). She composed a couple operas, writing both the music AND the libretto herself (not a very common thing to see).\n\n[Here's an opera composed by her](_URL_5_). As Boromir would say, you don't just write an opera. It's a hell of a lot of work, and it's kind of a particular type of music. It doesn't matter if it ends being average, getting to compose \"just another opera\" is pretty solid evidence of musical skill.\n\n > Do we know of any upper-class women who were favorably compared to notable professional artists or musicians?\n\n**Maria Theresia von Paradis (1759 – 1824)**. She was the daughter of the Imperial Secretary of Commerce and Court Councilor to the Empress [Maria Theresa](_URL_7_). She lost her sight at an early age. In her teens, she was giving concerts, singing and playing the piano (and probably the organ). She apparently commissioned concert works by Salieri, Mozart and Haydn.\n\n[Here's some music was composed by her](_URL_3_). Some times there is some confusion because there was this guy with a similar last name (Paradisi).\n\nBending a little the description you gave, we have **Barbara Strozzi (1619 – 1677)**. She was probably an illegitimate daughter of Giulio Strozzi (his family was rival of the Medici, those guys were very rich). She studied under Francesco Cavalli (very respected and influential opera composer). After the death of her husband, she supported herself investing some money and making money from her compositions. She was a prolific composer, and published plenty of music. It was expensive to publish music back then, people were not doing it just for fun... You would need to be either loaded or have good chances of success with your music, so I guess she can be compared to notable professionals. She also sang and played the lute pretty well.\n\n[I love this recording](_URL_9_) of one of her songs.\n\n**Marianne von Martinez (1744 – 1812)**. I don't know if she was very upper-class, but her family got a patent of nobility. She had the most amazing musical education and contacts! \n\nMetastasio (the top Italian librettist) was a friend of the family, and saw great potential in the little girl. So she took her under his wing. He got Haydn to giver her piano/harpsichord lessons. See, Joseph Haydn (who became one of the top musicians of the German speaking part of the world) and Nicola Porpora (who became an opera god) were her neighbours. Porpora gave her singing lessons, while Haydn accompanied her! Once she started composing, she took lessons from Hasse (super famous and super prolific opera composer). She met Charles Burney (a musicologist from those days, who managed to meet many interesting people). Apparently Mozart would visit the Martines some times, and he would probably play music for four-hands with her. Her music was known in many cities, but she got no official position (because that would be complete nonesense for a woman of her class).\n\n[Here's a harpsichord concerto](_URL_1_) by her. \n\nPardon the detour, but I guess I'll get to women born in less than super wealthy families.\n\n**Francesca Caccini (1587 – 1641)** was the daughter of Giulio Caccini, one of the founders of opera itself. She was well educated (standard humanistic curriculum of the time: Latin, Greek, literature, maths) and also had musical training (which I guess would have been pretty solid, considering who her father was). She performed for kings and super wealthy people, and composed. She was working at courts with Jacopo Peri (another founder of opera). She was probably the first woman to compose an opera (apparently wrote quite a good number of them). She taught music to the Medici princesses.\n\n[Here's an opera composed by her](_URL_0_).\n\n**Clara Schumann née Wieck (1819 – 1896)** was one of the top pianists, male or female, of the 19th century. She had a very, VERY long concert career. About 60 years!\n\nShe was a child prodigy, and received a very solid music education. She married Robert Schumann, who became a very relevant pianist, composer, and critic of music (he studied with her father). Her husband spent quite some time in psychiatric hospitals, and he famously injured himself by using a stupid contraption to improve his piano technique (he was not able to be a concert pianist after that). She became the main source of income for the family. She and Robert had 8 children, so she would hire housekeepers and cooks to take care of the house while she was on concert tours. She apparently rescued her kids during a revolution in 1849. She also took care of some of her grandchildren when her daughter Julie died. \n\nShe stopped composing at a young age, not feeling very confident in her skills. In my opinion, ANYBODY who was in her social circle would feel very incompetent as a composer... She was married to Schumann and was a very good friend of Brahms. She met Schubert, Chopin, and Liszt. By the way, all of them considered her a top notch pianist, so I guess she was super incredibly amazing.\n\n[Here's her piano concerto](_URL_6_). She was 16 when she composed it.\n\n**Guilhermina Augusta Xavier de Medim Suggia Carteado Mena (1885 – 1950)**. She was a top notch cellist, and became internationally famous (and kind of opened the possibility for women to become concert cellists in the 20th century). See, playing the cello was NOT something women were meant to do. It was considered a manly instrument, and the way the instrument has to be played...\n"
]
}
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[] |
[] |
[
[],
[],
[
"https://www.youtube.com/watch?v=WYfM65BSodA",
"https://www.youtube.com/watch?v=2r1lBdZAa54",
"https://www.youtube.com/watch?v=KUMMxsy4a88",
"https://www.youtube.com/watch?v=GKEM40potWw",
"https://www.youtube.com/watch?v=p5ovVrOPdVo",
"https://www.youtube.com/watch?v=P6icanZBZdQ",
"https://www.youtube.com/watch?v=bt_X-t1mX40",
"https://en.wikipedia.org/wiki/Maria_Theresa",
"https://www.youtube.com/watch?v=tTi-aj1ksBE",
"https://youtu.be/w2lBnocuMC0?t=15s"
]
] |
|
2sspgm
|
how do scientists determine how much water you need to drink?
|
The amount of daily water recommended seems ridiculously high. You would think that if your body is capable of doing anything naturally, it would be to tell you if you need water or not (such a fundamental resource). How do scientists determine that we should be drinking beyond what our bodies tell us?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2sspgm/eli5_how_do_scientists_determine_how_much_water/
|
{
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"cnshumz",
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"score": [
3,
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"text": [
"IIRC, the \"recommended amount\" of water per day has no real health benefits. Maybe a myth, may be a misconception.",
"The \"8 glasses of water per day\" thing is ridiculously high and is also a myth, apparently originally based on a misinterpretation of a 1940s article telling people to get 8 cups per day *including the water content of their food*. _URL_0_\n\nBut even that recommendation is somewhat suspect. Research hasn't conclusively shown what the \"correct\" amount of water per day is. There have been studies looking at health outcomes for different groups drinking different amounts, but again nothing really conclusive. \n\n"
]
}
|
[] |
[] |
[
[],
[
"http://fivethirtyeight.com/features/you-dont-need-8-glasses-of-water-a-day/"
]
] |
|
1ke9yu
|
Why are there so many species of birds compared to other tetrapod vertebrates?
|
There are way more species of birds than amphibians, reptiles, or mammals. Why, from an evolutionary perspective?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1ke9yu/why_are_there_so_many_species_of_birds_compared/
|
{
"a_id": [
"cbodwcy"
],
"score": [
3
],
"text": [
"So this is neat because birds are also the phylogenetically youngest of the tetrapods. The big reason is that birds, by virtue of flying, opened up a mostly unexploited niche (habitat) space that they could fill without competition. They could then partition this new habitat leading to speciation (in a process very similar to the cichlids in lake Malawi).\n\nAdditionally, the ability to fly allowed them to colonize islands without large predators and to escape predation by simply being out of reach. This released selective pressure on camouflage and is in part why birds are some of the most colorful and ornate tetrapods. Color and plumage were then reinforced through sexual selection, again leading to speciation."
]
}
|
[] |
[] |
[
[]
] |
|
kb7s9
|
Have humans always had to brush their teeth to avoid rotting?
|
I cannot think of any animals in nature that need to brush their teeth? However, I'm not sure if wild animals' teeth rot or not. Aside from the domestic dog that the owner brushes for them.
|
askscience
|
http://www.reddit.com/r/askscience/comments/kb7s9/have_humans_always_had_to_brush_their_teeth_to/
|
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"The short answer is that no, brushing of the teeth wasn't necessary. Humans didn't live nearly as long until recently, and there was no reason to evolve more long-lasting teeth.\n\nThe long answer is that there is no selective pressure to produce teeth that last longer. Teeth don't usually start getting seriously rotten until our third decade of life or so. At this point, we're already well past sexual maturity and, in prior millenia, would have likely reproduced. Remember, unless a trait gives a reproductive advantage, there's no selection for it.\n\nA related phenomenon is that humans and their ancestors didn't live nearly as long in the past. The set of teeth that we have is perfectly sufficient for a lifespan of 25 or 30 years. As we've dramatically expanded our lifespan, we've had to come up with ways to preserve the teeth we have (by brushing them), or replace them altogether (with dentures).\n\n\n",
"In an extension to this question, I have read that dental decay was not as much of an issue in the past until we developed grain agriculture. I could not find any sources in a cursory google. Does this have truth to it?",
"Related question: As a child in science camp I had a teacher who claimed that people used [this plant](_URL_4_) (equisetum, or horsetail as he called it) to clean their teeth. This was in the pacific northwest, so I assume he was referring the indigenous people of that area, but my memory is unclear. The wiki article claims a very large global distribution (excluding Antarctica). The only reference in the article to usage by Native Americans is this:\n\n > Indians of the North American Pacific Northwest eat the young shoots of this plant raw....... Horsetail was often used by Indians to polish wooden tools.\n\nFrom [Distribution, ecology, and uses.](_URL_1_)\n\nUnsubstantiated mention of use as polish [here](_URL_2_) (no mention of teeth):\n\n > Contains so much silica that bunches of the stem have been sold for polishing metal and used to be imported into England from Holland for the purpose, hence the popular name of Dutch Rushes. It was also called by old writers Shave-grass, and was formerly much used by whitesmiths and cabinet-makers.\nWas employed in England for scouring pewter and wooden kitchen utensils, and hence called Pewterwort. Fletchers and combmakers rubbed and polished their work with it, and the dairy-maids of the northern counties used it for scouring their milk-pails.\nNative Americans and Mexicans used the dried stems to scour cooking pots while early American carpenters and other craftsman used the dried stems to smooth and polish woods, ivory, and metals.\nUsed in the past to give wood, ivory, silver, pewter and brass a fine finish. The high silicon content in the stems acts as a gentle but effective polish. Bunches of the rush were used to scour milking pails or scrubbing pots in the kitchen. Even now, it could be very useful to campers.\n\nAlso, this (unsubstantiated?):\n\n > Horsetail contains silicon, which plays a role in strengthening bone. For that reason, it is sometimes suggested as a treatment for osteoporosis.\n\n[Source.](_URL_6_) Could that effect apply to teeth as well as bone?\n\nOld trusty google also found this little discussion: [in comments](_URL_5_)\n\nDoes anyone have information on the use of this plant in the claimed manner?\n\nAnd, after further investigation, I think that it would be very beneficial to have an anthropologist join this discussion. See:\n\n[Chewing sticks](_URL_0_)\n\nAnd especially: [Miswak](_URL_3_)\n\n\n",
"Art History student here. This topic came up in class one day, when a classmate asked why in lots of portraits from the renaissance era didn't seem to have bad teeth, but after 1750ish, they were either fake teeth or rotted. The professor explained that it had a lot to do with the sugar plantations in the Caribbean. Before, sugar used to be a huge luxury, and was not really part of the diet. With cheap sugar from the Indies coming in, Europeans started eating a lot of it, and cavities have been an issue ever since.",
"The main reason humans now get cavities much more frequently now is the change of our diet. Since the industrial revolution, processed foods have become readily available. Bacteria is the primary cause of oral diseases such as cavities (rotting of the teeth). Because of the prevalence of sugars and foods/beverages that makes our mouth more acidic and provides harmful bacteria a source of nutrients, there is a better chance harmful bacteria will thrive. \nAnimals do have this type of diet and many times, as they chew food, the mechanical action of the food rubbing against their teeth is like our act of brushing teeth. And as mentioned, you also don't see a lot of animals living to be as long as us so you simply died because they got cavities large enough to affect their teeth.\n",
"I asked my dentist this exact question, largely because I was/am skeptical of modern dentistry. He mentioned learning about a tribe of people living in the rainforest that chewed on the bark of a tree to keep their teeth clean. It turned their teeth black, but everyone did it so black teeth were normal.",
"Elephants generally die from starving to death (if they live to old age) because the last of their teeth fall out and they can not eat.",
"I am not a scientist, but I am super-sad that the top-voted comment includes reference to humans only living 25-30 years. This is a pretty big misconception. Infant mortality rates used to be HUGE, which had a pretty big impact on averages. Life-spans are longer now than they ever were historically, but not by double or anything crazy. \n\nAsk your dentist, the primary cause of tooth rot is sugar, sugar, more sugar, and starch (which is still sugar). Animals that don't eat sugar (or grain-based pet foods in the case of our beloved domesticated cats, dogs, cows, etc) don't need to brush their teeth because their teeth don't rot nearly as fast as ours do. If we didn't eat so much sugar/starch ours wouldn't either. In the past (read: pre-agriculture), we didn't. ",
"The short answer is that no, brushing of the teeth wasn't necessary. Humans didn't live nearly as long until recently, and there was no reason to evolve more long-lasting teeth.\n\nThe long answer is that there is no selective pressure to produce teeth that last longer. Teeth don't usually start getting seriously rotten until our third decade of life or so. At this point, we're already well past sexual maturity and, in prior millenia, would have likely reproduced. Remember, unless a trait gives a reproductive advantage, there's no selection for it.\n\nA related phenomenon is that humans and their ancestors didn't live nearly as long in the past. The set of teeth that we have is perfectly sufficient for a lifespan of 25 or 30 years. As we've dramatically expanded our lifespan, we've had to come up with ways to preserve the teeth we have (by brushing them), or replace them altogether (with dentures).\n\n\n",
"In an extension to this question, I have read that dental decay was not as much of an issue in the past until we developed grain agriculture. I could not find any sources in a cursory google. Does this have truth to it?",
"Related question: As a child in science camp I had a teacher who claimed that people used [this plant](_URL_4_) (equisetum, or horsetail as he called it) to clean their teeth. This was in the pacific northwest, so I assume he was referring the indigenous people of that area, but my memory is unclear. The wiki article claims a very large global distribution (excluding Antarctica). The only reference in the article to usage by Native Americans is this:\n\n > Indians of the North American Pacific Northwest eat the young shoots of this plant raw....... Horsetail was often used by Indians to polish wooden tools.\n\nFrom [Distribution, ecology, and uses.](_URL_1_)\n\nUnsubstantiated mention of use as polish [here](_URL_2_) (no mention of teeth):\n\n > Contains so much silica that bunches of the stem have been sold for polishing metal and used to be imported into England from Holland for the purpose, hence the popular name of Dutch Rushes. It was also called by old writers Shave-grass, and was formerly much used by whitesmiths and cabinet-makers.\nWas employed in England for scouring pewter and wooden kitchen utensils, and hence called Pewterwort. Fletchers and combmakers rubbed and polished their work with it, and the dairy-maids of the northern counties used it for scouring their milk-pails.\nNative Americans and Mexicans used the dried stems to scour cooking pots while early American carpenters and other craftsman used the dried stems to smooth and polish woods, ivory, and metals.\nUsed in the past to give wood, ivory, silver, pewter and brass a fine finish. The high silicon content in the stems acts as a gentle but effective polish. Bunches of the rush were used to scour milking pails or scrubbing pots in the kitchen. Even now, it could be very useful to campers.\n\nAlso, this (unsubstantiated?):\n\n > Horsetail contains silicon, which plays a role in strengthening bone. For that reason, it is sometimes suggested as a treatment for osteoporosis.\n\n[Source.](_URL_6_) Could that effect apply to teeth as well as bone?\n\nOld trusty google also found this little discussion: [in comments](_URL_5_)\n\nDoes anyone have information on the use of this plant in the claimed manner?\n\nAnd, after further investigation, I think that it would be very beneficial to have an anthropologist join this discussion. See:\n\n[Chewing sticks](_URL_0_)\n\nAnd especially: [Miswak](_URL_3_)\n\n\n",
"Art History student here. This topic came up in class one day, when a classmate asked why in lots of portraits from the renaissance era didn't seem to have bad teeth, but after 1750ish, they were either fake teeth or rotted. The professor explained that it had a lot to do with the sugar plantations in the Caribbean. Before, sugar used to be a huge luxury, and was not really part of the diet. With cheap sugar from the Indies coming in, Europeans started eating a lot of it, and cavities have been an issue ever since.",
"The main reason humans now get cavities much more frequently now is the change of our diet. Since the industrial revolution, processed foods have become readily available. Bacteria is the primary cause of oral diseases such as cavities (rotting of the teeth). Because of the prevalence of sugars and foods/beverages that makes our mouth more acidic and provides harmful bacteria a source of nutrients, there is a better chance harmful bacteria will thrive. \nAnimals do have this type of diet and many times, as they chew food, the mechanical action of the food rubbing against their teeth is like our act of brushing teeth. And as mentioned, you also don't see a lot of animals living to be as long as us so you simply died because they got cavities large enough to affect their teeth.\n",
"I asked my dentist this exact question, largely because I was/am skeptical of modern dentistry. He mentioned learning about a tribe of people living in the rainforest that chewed on the bark of a tree to keep their teeth clean. It turned their teeth black, but everyone did it so black teeth were normal.",
"Elephants generally die from starving to death (if they live to old age) because the last of their teeth fall out and they can not eat.",
"I am not a scientist, but I am super-sad that the top-voted comment includes reference to humans only living 25-30 years. This is a pretty big misconception. Infant mortality rates used to be HUGE, which had a pretty big impact on averages. Life-spans are longer now than they ever were historically, but not by double or anything crazy. \n\nAsk your dentist, the primary cause of tooth rot is sugar, sugar, more sugar, and starch (which is still sugar). Animals that don't eat sugar (or grain-based pet foods in the case of our beloved domesticated cats, dogs, cows, etc) don't need to brush their teeth because their teeth don't rot nearly as fast as ours do. If we didn't eat so much sugar/starch ours wouldn't either. In the past (read: pre-agriculture), we didn't. "
]
}
|
[] |
[] |
[
[],
[],
[
"http://en.wikipedia.org/wiki/Teeth_cleaning_twig",
"http://en.wikipedia.org/wiki/Equisetum#Distribution.2C_ecology_and_uses",
"http://www.rook.org/earl/bwca/nature/ferns/equisetumhye.html",
"http://en.wikipedia.org/wiki/Miswak",
"http://en.wikipedia.org/wiki/Equisetum",
"http://www.flickr.com/photos/yokohamayomama/5725520067/",
"http://www.umm.edu/altmed/articles/horsetail-000257.htm"
],
[],
[],
[],
[],
[],
[],
[],
[
"http://en.wikipedia.org/wiki/Teeth_cleaning_twig",
"http://en.wikipedia.org/wiki/Equisetum#Distribution.2C_ecology_and_uses",
"http://www.rook.org/earl/bwca/nature/ferns/equisetumhye.html",
"http://en.wikipedia.org/wiki/Miswak",
"http://en.wikipedia.org/wiki/Equisetum",
"http://www.flickr.com/photos/yokohamayomama/5725520067/",
"http://www.umm.edu/altmed/articles/horsetail-000257.htm"
],
[],
[],
[],
[],
[]
] |
|
1j5hdx
|
How did the Gauls manage to muster so many men during the Gallic War?
|
So, Roman armies were larger than Medieval armies thanks to the state being better organized and such, right? But how was it that the Gauls managed to amass so many so men, having no state-level organization?
What kept them from all starving to death? Where did their food come from?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1j5hdx/how_did_the_gauls_manage_to_muster_so_many_men/
|
{
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"cbbastp"
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"So I'm assuming you mean the Gallic Wars that occured during the Roman Republic involving Caesar's conquest.\n\nThe Romans did have better organization, but did not, many times have larger armies than the medieval world. The average legion was about 6,000 men, and a large Roman army composed maybe 3 of them at the most during a campaign. Caesar had four, Legio X, Legio VII, Legio VIII, and Legio IX Hispana. Of course take in replacements and auxilaries as well as guards for the logistics, you have about 50,000 participants, only about 24,000 would be capable of fighting in theory. The Gauls were a confederation, true, but this did not mean they couldn't summon large amounts of soldiers, especially in defense of their homeland. The idea that the Gallic people were barbarians is a myth as well. The Gallic people were very civilized, something that most Roman merchants who worked with them concurred with (although nowhere near the degree of the Romans, they would also tell you). They also had the ability to call on all the different tribes to help them out. So even though they didn't have the complex logistics to support a large field army in foreign lands, they definitely could field a large temporary army made mostly of militia and irregulars for a short amount of time and very close to home. Their food came from their own units, they did have some limited supply issues, but largely each unit could hold their own. Keep in mind as well, that the numbers that we hear of were largely those that Caesar himself estimated, and I'm sure that they were inflated to a large degree.\n"
]
}
|
[] |
[] |
[
[]
] |
|
30odgd
|
why do we have summer and winter time? wouldn't it be easier to shift the clock half an hour in one direction and leave it that way all year?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/30odgd/eli5_why_do_we_have_summer_and_winter_time/
|
{
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"cpuaq1r"
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"text": [
"It started as a way to help farm families manage work and school time. It stuck because it saves many millions of dollars in energy each year. Reduces stress on the power grid and other benifits. Adjusting humans can be done, the sun just is so set in its ways."
]
}
|
[] |
[] |
[
[]
] |
||
2b6cqd
|
Could planets survive the heat death of the universe? Or Would they degrade also.
|
askscience
|
http://www.reddit.com/r/askscience/comments/2b6cqd/could_planets_survive_the_heat_death_of_the/
|
{
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"text": [
"If the planets are far enough from their stars when they die, so as not to get caught in a supernova or planetary nebula, the planets would be stable for arbitrarily long times. They'd get really cold though."
]
}
|
[] |
[] |
[
[]
] |
||
2o7y6u
|
why is it conservative media in the us usually stands against minorities in alleged police brutality cases?
|
I'm black and am studying in the US, but my country of origin is elsewhere. I understand the rationale for conservative support for low taxes, less government regulation etc; but I don't get why they would be on the side of the police in cases of alleged excessive force.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2o7y6u/eli5why_is_it_conservative_media_in_the_us/
|
{
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"I think you'd have to provide some specific evidence here. Most of the stuff I've seen is them pointing out in the Michael Brown case that the rest of the media was really quick to label him a blameless victim and pointing out all of the contrary evidence.",
"Conservatives in the us are not like conservatives in the rest of the world. The Republican Party supports \"traditional values.\" This is often one in the same with either Christian values or family values. This can largely encompass respect for authority and therefore they support the police officers. Also, all conservatives support stability and so they would be against revolting. Finally, conservatives stand firm that the ferguson case was self defense and not supporting wilsons right to protect himself is bad for guns rights. ",
"It's probably incorrect to treat any group as being monolithic and all members sharing the same rationale for supporting their position.\n\nHowever, as far as the United States is concerned, it's important to consider the impact that race has on this debate.\n\nThe police cases that have gotten the most publicity lately have involved white officers with black members of the public.\n\nIn the US, conservatives are largely members of the Republican Party. That party's members tend to be older and whiter than the the Democratic party, which is generally considered to be the liberal party. Democrats tend to be younger, with much more racial diversity.\n\nIn this context, the Republican party tends to focus on law and order, while Democrats tend to focus more on individual freedom and view police actions with more suspicion.\n\nRace is a big factor in this issue because the Republican party tends to dominate in the South where this is a long history of slavery and discrimination against blacks, and in wealthy suburbs where many whites have relocated to escape living around blacks. \n\nThus, when police actions and race collide, many Republicans tend to identify more with the white officer and view the person of color with suspicion, while many Democrats tend to identify more with the person of color and view the white officer with suspicion.\n\nThis is a gross over-generalization.\n\n\n\n"
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
n2emz
|
why we think pirates talk the way they do
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/n2emz/eli5_why_we_think_pirates_talk_the_way_they_do/
|
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"_URL_0_\n\nNumber 6.",
"What we came to know as \"Pirates\" (e.g. treasure maps marked with an \"X\", schooners, the Black Spot, tropical islands, and one-legged seamen carrying parrots on their shoulders etc.) all came from the novel Treasure Island by Robert Louis Stevenson (1823). \n\n\n\n ",
"I once heard a very old recording, of a sailor who was old when the recording was made, singing sea chanties. His accent sounded exactly like Popeye, but much stronger. \n\nDuring the classic age of sail, people in different parts of the world had very strong accents, as there was no broadcast standard for people to emulate. Sailors started out with these strong accents, and many grew up speaking different languages. All the world's English speaking sailors would have developed their own distinct, global dialect, while people from the North and South sides of London could hardly understand each other's speech.\n\nFor an analogy, see the [Military basic](_URL_0_) accent, in modern American English (middle of the page). Then imagine how much stronger the accent would be if the speakers didn't watch TV in standard English, or call home regularly.\n\nAs LindLTaylor points out, our ideas about pirates come from Robert Louis Stevenson. But the author, and readers at the time, knew sailors had a disticnt way of speaking.\n\nOh, crap, this is eli5. Old time sailors talked funny, sort of like Popeye. Our ideas about pirates come from one make believe story. The guy who wrote it knew sailors taked funny, but the book probably isn't quite accurate. ",
"_URL_0_\n\nNumber 6.",
"What we came to know as \"Pirates\" (e.g. treasure maps marked with an \"X\", schooners, the Black Spot, tropical islands, and one-legged seamen carrying parrots on their shoulders etc.) all came from the novel Treasure Island by Robert Louis Stevenson (1823). \n\n\n\n ",
"I once heard a very old recording, of a sailor who was old when the recording was made, singing sea chanties. His accent sounded exactly like Popeye, but much stronger. \n\nDuring the classic age of sail, people in different parts of the world had very strong accents, as there was no broadcast standard for people to emulate. Sailors started out with these strong accents, and many grew up speaking different languages. All the world's English speaking sailors would have developed their own distinct, global dialect, while people from the North and South sides of London could hardly understand each other's speech.\n\nFor an analogy, see the [Military basic](_URL_0_) accent, in modern American English (middle of the page). Then imagine how much stronger the accent would be if the speakers didn't watch TV in standard English, or call home regularly.\n\nAs LindLTaylor points out, our ideas about pirates come from Robert Louis Stevenson. But the author, and readers at the time, knew sailors had a disticnt way of speaking.\n\nOh, crap, this is eli5. Old time sailors talked funny, sort of like Popeye. Our ideas about pirates come from one make believe story. The guy who wrote it knew sailors taked funny, but the book probably isn't quite accurate. "
]
}
|
[] |
[] |
[
[
"http://www.cracked.com/article_19482_6-absurd-pirate-myths-everyone-believes-thanks-to-movies.html"
],
[],
[
"http://tvtropes.org/pmwiki/pmwiki.php/Main/AmericanAccents"
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[
"http://www.cracked.com/article_19482_6-absurd-pirate-myths-everyone-believes-thanks-to-movies.html"
],
[],
[
"http://tvtropes.org/pmwiki/pmwiki.php/Main/AmericanAccents"
]
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||
1rsqkz
|
what is math and why does it work?
|
what is math. We have algebra,calculus etc.but what is math in real world? I know it might be a stupid question but is math only something we use to describe our world , or why does it even work ,what does it even study, did we discovered math or did we invented math, why there even is math?...you know, the thought before sleep
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1rsqkz/eli5what_is_math_and_why_does_it_work/
|
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"One of the problems I see with a lot of the explanations here is that they are focused strictly on one type of mathematics. Mathematics is a large topic that encompasses many parts. As such I share the definition that I share with my students:\n\nBorrowed from \"The Language of Mathematics: Making The invisible Visible\"\n\nMathematics is the science of patterns...\n\nArithmetic and number theory study patterns of number and counting. \nGeometry studies patterns of shape. \nCalculus allows us to handle patterns of motion. \nLogic studies patterns of reasoning. \nProbability theory deals with patterns of chance. \nTopology studies patterns of closeness and position. \n\nEDIT:\n\nI feel it is necessary to address several of the comments and an edit is the best way to do so.\n\n1. **Saying Math is the Science of Patterns is too broad.** Yes you would be correct in that statement. Except there was also context provided with that statement. Looking at each of the main topics gave examples of each of the types of patterns studied. Math does not study every single pattern that exists, just ones that relate to it. \n\n2. **Math is no empirical to be considered a science.** I have one issue with this particular statement. If math is not empirical enough to be considered a science. How is it that we can use math to make other sciences empirical? Physics is a scientific field that is heavily influenced by mathematics. It uses it mathematical statements all the time as empirical evidence. Where the issue comes in, I believe is how math is empirical. In other fields of science, they use another field to give empirical evidence. Physics uses math, Chemistry uses math and physics, and so on and so on. In math to prove something, we use math. Which you would think creates this self-fulling prophecy but it really doesn't. TL/DR: If math isn't empirical neither is any other science as they are based on math.\n\n3. **Math is Logic.** Ehhh. Yes and no. Yes, math uses a lot of logic to help prove numerous statements. If you look at one of the parts of the definition though it says, \"Logic studies patterns of reasoning.\" Saying that math is logic only allows you to analyze a very small part of mathematics. Again, mathematics is a huge topic so we need to be careful when trying to define it. There is no perfect definition sadly and everyone will disagree on numerous points. Definitions of math is numbers, logic, or whatever else may have been said is extremely limiting though.\n\n4. **Math is a language.** While I do disagree with this statement it is an interesting discussion to have. The way we see math used on a daily basis is in a base 10 system. The notation we are familiar with was created to shorten statements down to \"equations.\" The notation we use was really just created to make creating multiple copies of books (back when everything was hand written) easier and to a degree when the printing press was invented. In the past, we would have said stuff like: \n\n\"When two numbers are added, their order is not important.\"\n\nWe would not write that as: a + b = b + a\n\nIf we want to talk about the patterns that exist outside of notation than I would agree with you that mathematics is a language.\n\n5. Final statements. Understand that math is an enormously large topic. It is easy to be focused on one specific part of math because that is what we have been exposed to most. Few ever see the entirety of mathematics and truly understand it. I wish I was one of those lucky people but sadly, I am not. \n\nI use this definition in my classes for the sheer fact that it hopefully allows my students to think beyond what they are exposed to on a regular basis. As a trial, I usually have them make their own definition before providing them this one. Typical answers usually include math is numbers, torture, or various other quips. Use this definition as not an end all be all, but a starting point. Let it open up your perception of mathematics beyond what you already know and explore other parts. Numbers and equations are such a small part of mathematics.",
"This is a very interesting question. I think you might find related the work of Hilbert, a German philosopher/mathematician, and those who were working at a similar time in related fields, such as Godel and Russell.\n\nMaths essentially works by stacking proofs on top of each other. Essentially, you take some things you know and re-arrange, combine and manipulated them so that they tell you something else. These proofs build on each other, and it's essentially that way that maths gets done.\n\nIn the early 20th century there was a movement, lead by Hilbert, pushing to try to logically ground all mathematics in a number of basic propositions (axioms) that were consistent, finite and complete - this was called the Formalist movement.\n\nIt all gets pretty complicated here. But the Formalist and Logicist (that is, a group trying to reduce all maths to logic) movements essentially failed. Godel's incompleteness theorems showed these goals to be essentially impossible.\n\nI'm not really sure where that leaves maths. I hope I've told this story well enough - it's not an area of expertise for me, only one of interest. I'm also not sure if it really answers your question all that well, but I may as well put it out there for people to see.",
"Mathemathics is a **very** big subject. People have been discovering new things for thousands of years that have all been classified as \"maths\".\n\nWhen you go about your daily life you do math all the time. Lets say you have a family of five, but only three pieces of candy. You then immediately know that there is not enough candy for everyone, you'd need two more.\n\n\"Formal\" mathematics is to take something like that candy situation, remove unneccesary details like the words \"person@ and \"candy\", then figure out a good way to write it down, for example \"3 - 5 = -2\". Once you've done that you have not only written down the solution to the candy problem, you have also defined the operation of subtraction. And that operation can be reused as often as you'd like.\n\nMore advanced maths is just the same thing for more advanced problems. You want to make a good map? Think about the problem, remove details, write it down, maybe use that clever subtraction operator from earlier to simplify what you wrote. Boom, geometry. Want to figure out how speed and acceleration are related? You're gonna need to invent some calculus for that.\n\nAfter thousands of years of clever discoveries we now have a huge toolbox of operations, methods, formulas and so on, which, if you know how to use them, will let you solve some really difficult problems.\n\nAs it turns out, people all across the world figured many of the same things out independently. It turns out math is the same everywhere. Mathematicians don't invent, they *discover*.\n\nThis means that we can use math to figure out how *anything* in the universe works. Physics is taking math then adding some details again. That's how we can look at a star in the sky, measure what color it's light is, check what elements make that color, then tell what the star is made of, what way it is moving in relation to the earth, how old it is, etc. All without ever going there, because we know that math is the same there too.",
"Who/how was it figured out that ten digits could be used to express so many things and that they all fit together in patterns?",
"In my opinion its counterproductive to start thinking about mathematical models of the real world when trying to understand what math is.\nFirst of all, math isn't a natural science at all. It's a science of structures. And the beauty of it is that you can study any structure you can think of. There is no actual need for validation in this universe when studying structures mathematically.\n\nNow, I don't know who said it, but one of my favourite quotes about this said something like \"Mathematics is the only science you can still do if the universe ceases to exist tomorrow.\"\nWhat most mathematics boils down to nowadays is pretty simple: You define a basic set of rules for a structure (mostly through axioms and properties of sets you wish to examine) and then, trough logic (in whichever logic system you chose), deduct further properties of your structure, mostly under new restrictions that are or seem interesting.\n\nNow what is a really good question indeed is why it \"works\" so well in our human world. People have been doing arithmetic for about as long as we have recorded documents of history. Euclidian Geometry has been around since, well, Euclid in ancient Greece, possibly longer.\nI'd argue that for the longest time, mathematics was merely a tool for other fields to better understand our world, but people for the longest time didn't think about the underlying structure of their thoughts regarding the tools. Most \"mathematicians\" like Newton, Laplace, Pascal, Eucild, Leibnitz or Pythagoras were'nt even mathematicians per se.\nThey studied nature and used mathematics when it was neccessary (and often developed new techniques for their cases). The \"modern\" way of mathematics started arguably with Cauchy, who was one of the first to regard mathematics as a discipline in itself.\nBut it's only natural for it to develop that way.\n Mathematics works because there seems to be a universal logic to the our universe. So while studying real objects, you come across these patterns and structures you can abuse to get to know a little bit more about yourself and the world you live in. Until at some point you realize\nthat there is a way to formalize these observations for more general objects and so on.\nThink about a lumberjack. He's using his axe to chop wood, and maybe learns a thing or too about his axe on the way to become more efficient. A mathematcian would dissect the axe, and come up with a way to describe the axe with very general outlines for structures (to stay with this picture, lets say the need for a \"handle\" and a \"sharp contact surface\").\nHe would break down the axe so far, you would'nt even recognize it. But by analyzing the underlying principles, he would gain a deeper understanding while reconstructing the axe from his assumptions.\n\nThe crazy thing is how efficient mathematics works in itself. There are so many fleshed out theories that don't have any use for \"real world problems\" yet. Absolving itself from the dependence on other natural sciences seems to have speed up the process.\nThere is of course the poster child of modern mathematics, Graph Theory, with it's direct links to computer science, but every field has results defying any connection to other fields.\nWhat's unique about mathematics is that you can obtain \"absolute truths\" in the set of rules and restrictions YOU defined. As long as human thinking and logic is consistent, mathematics allows for these kinds of judgement. \nThat is why proofs are so important. Instead of testing your theory with observation of the universe, you test it with logic on your assumptions for your structure. Proofs are a way to show the logic connection between results and assumptions.\n\nI don't know how much that helps, but these are my ramblings as I'm still studying at university right now. But here are some things I think Math is not (as in \"not only\"):\n\n1. Math isn't arithmetic. I haven't used a calculator since I started university.\n2. Math isn't numbers. There are tons of Theorems/Results or even branches of mathematics that don't even need numbers (or structures that act a lot like our number system, groups/fields/rings).\n3. Math isn't Applied Math. Every time someone asks what I'm doing all day it's hard to make people understand that you don't need an actual application of the findings.\n\nHere are some hints to topics that maybe help grasp the spectrum of mathematics a bit better:\n\n1. Zermelo-Fraenkel set theory in first order logic _URL_1_\n2. Functions _URL_2_\n3. Abstract Algebra _URL_4_\n4. Topology _URL_0_\n\nAnd last but not least, my favourite theorem and a good example of the difference between an application and a fleshed out, theoretic version of the \"same\" thing: Stoke's Theorem _URL_3_\n Note the difference between the usage in physics and it's modern version in mathematics using differential forms.",
"I'll explain by analogy. Think of a game, like chess. Chess has specific rules on what you can do and what you can't do. It has specific results for every action. Really chess is defined as just a set of rules and a specific environment (board and pieces) on which these rules apply.\n\nBut from a simple base structure like this, we can play a huge number of interesting games. It's mind-boggling how many different unique games are possible in Chess. Just a simple game with simple rules like Chess has given us millenia of interesting games and entertainment.\n\nThen there are other games like Tic-Tac-Toe, which are also simple but very limited in their possibilities. Here you have used a different set of rules, but generated only a small universe of possibilities, in stark contrast to Mathematics.\n\n---\n\nMath is exactly like that. Modern mathematics is rooted in specific axioms and rules, and we then explore the vast universes that are created by those rules. Say you define some objects with some properties and then some rules about what they can do. You have a system that you can explore now. Using only the axioms, you can prove certain things and disprove other things. The amazing thing here is, that if you can find ANY real life objects that happen to have those properties and follow those axioms, you will get the same result in a real-world setting.\n\nSo, the math that everyone is used to (numbers, functions, calculus) is really just describing some abstract objects that have to play by some abstract rules. The reason is work in the real world is because a lot of the objects in the real world behave like those abstract objects and follow those rules.\n\nThat said, there are many fields of mathematics where this is not true. You can come up with many systems for which you won't be able to find any tangible use because nothing you can think of or find, actually works like that. But regardless, if you did find something - you would know a whole lot about it as a result of the theorems you've proven.\n\nA lot of people feel the need to state that Mathematics is merely a system used to model the universe, but this is not true. There are many fields or spaces that you can explore in Mathematics that are not relevant or related to the physical universe. Whether or not this is the purpose of Mathematics is not a question I wish to address. Our's is but one universe that is explorable through the use of mathematics.\n\n---\n\nIn recent history, we've been getting better and better at abstraction to the point where we have almost captures all the fields of mathematics under one umbrella of rules. For a while, it was taught that set theory could be the complete foundation of mathematics, but now have found areas that don't come under set theory at all.\n\nThere is also the deal with how we define and approach logic. That's all very philosophical. You can read more up on [mathematical logic here](_URL_0_).\n\n---\n\nAt the heart of it, Mathematics is the art of taking some objects and some specific rules about what you can do with these objects and then exploring the universe that is created out of it.",
"I refer you to this: _URL_0_ which refers to a seemingly unique tribe living in the Amazon whithout numbers.\n\nA few paragraphs of reading will tell you they have great difficulty drawing a straight line or describing even simple numbers like one and two.\n\nThey can trade nuts they gather and women with neighboring tribes, but cannot count even after months of lessons. Neither can they describe their history or traditions beyond a generation or two.\n\nIt would seem from this evidence that numbering is an essential part of modern human society. That without numbering we remain simple hunter-gatherers without the ability to build a sophisticated society.\n\nPerhaps the cro-magnon did not have numbers either.\n\nMore than 60 years ago, amateur linguist Benjamin Lee Whorf argued that learning a specific language determined the nature and content of how you think.\n\nThat theory fell into intellectual disrepute after linguist Noam Chomsky's notions of a universal human grammar and Harvard University professor Steven Pinker's idea of a universal language instinct became widely accepted.\n\n\"The question is, is there any case where not having words for something doesn't allow you to think about it?\" Prof. Gordon asked about the Piraha and the Whorfian thesis. \"I think this is a case for just that.\"\n\n",
"Mathematics is the study and application of abstract reasoning.\n\nIt should be noted that our modern day notion of \"Mathematics\" did not always exist. Today, Mathematics is all about establishing a consistent axiomatic system and then making deductions. In the old days of the Egyptians, this was not the case. To the Egyptians, Babylonians and etc, Arithmetic and Geometry were practical sciences based off of empirical evidence and not sound reasoning. Because of this, these people made many gross errors which we would think obvious.\n\nExample: The Egyptians thought that the area of an arbitrary quadrilateral was A=(a+c)*(b+d)/4 where a,b,c,d are the lengths of the sides of the quadrilateral in adjacent order. The Egyptians saw that this formula was true for rectangles and squares, and it \"looked right\", so they accepted it as fact blindly.\n\nIt wasn't until Thales of Miletus came around at about 600 B.C. that our current day notion of Mathematics was born. He was the first to demonstrate that the circle is bisected by its diameter through deductive reasoning. The circle is bisected by a diameter not because it looks like it. The circle is bisected by a diameter because if it did not, then at least one commonly accepted assumption about circles must be false.\n\nThis is the heart of Mathematics. Something isn't true simply because we haven't found an example of it being false. Something isn't true simply because someone else said it is true. In Mathematics, something is true because it can be shown to be true through rigorous reasoning.\n\nSadly, most people go through their entire academic career being taught a subject called Mathematics which really isn't Mathematics at all.",
"I'll try answering this as simply as I can.\n\n > did we discovered math or did we invented math\n\n\nMath has been there all along, since the universe began. 1+1 has always equaled 2, whether humanity discovered it or not, right?\n\nWe chose to give specific meaning to specific things we call numbers and symbols so that we could start TALKING about the math that has been there all this time.\n\n > why there even is math?\n\nThere is math because some wise ancestor decided to count things and trade things with others. It became so complex because of all the contributions people made over so many centuries.\n\n > why does it even work\n\n\nMath works because it all depends on very basic assumptions. Think of them like building blocks. You have these 10 or 15 or 20 assumptions, and you start to come up with rules based on these assumptions. This works if we assume simple things, such as \"If we take any two points on any one piece of paper, and use a straightedge to connect them, we will have made a line.\"\n\nMathematicians use these assumptions to build new and exciting theories and results. Then someone else takes THOSE results and makes something out of them. Just like working with building blocks. If the logic of going from one building block to the next is good, then the result is also valid.\n\n > what does it even study\n\nThere are a LOT of branches of mathematics, and they're different (but very well connected). I can't really answer this one.\n\n > is math only something we use to describe our world\n\nMath can be used to describe any world, because it only depends on logic being valid.\n\n\n > what is math in real world?\n\nIn the real world, math is mostly finance, probability, and statistics. Businesses need to be able to add things up to do their taxes and other documentation. Probability and statistics are used to manage risk in the real world. In the real world, anything can happen, and probability and statistics are used to try and predict these things and work around them or with them.",
"\"Mathematics is the science of not getting laid.\"",
"Mathematics, at its core, is a series of logical patterns and conclusions that can be drawn from our observations of the world around us. Numbers themselves are a construct to represent the idea of an amount. Of what? Well, it doesn't really matter because it's just an abstraction.\n\nBasic manipulations of those numbers (\"I have 2 apples, I will get 1 more apple, I now have 3 apples\") leads to basic arithmetic. Above is an example of addition. In addition, we can demonstrate subtraction (\"I have 3 apples, I will throw 1 apple, I now have 2 apples\"). We can build up on that basic concept with more advanced manipulations (\"I have 3 apples. I will steal 2 apples for every apple I have right now\") to demonstrate multiplication. It's very, very difficult to make a logical statement that can disprove these sorts of rules, and any proof you can find will have some logical missteps in them.\n\nMany of these ideas can be derived purely from observation, and many of the more fundamental mathematical concepts can be made more concrete. For example, 2 + 1 = 3 is the previous apple example. Now, what if we wanted to use similar concepts for problem solving? Well, I know I can steal 2 apples at a time from you, and I want 20 apples. How many trips do I have to make while you're not looking? That leads us to super basic algebra, in the form of 2 * x = 20. This is one of the reasons why word problems are important when teaching kids math. It's supposed to teach them how a real-world problem can be boiled down to a math problem, which can be solved on paper. Or, more succinctly, how a real problem can become an abstract one, which is usually much easier to solve.\n\nThese sorts of ideas have led to a set of rules called *postulates*, of which there are many. I may be mistaken in this assumption, but it's very difficult or impossible to prove a postulate. They are the absolute fundamental building blocks of what we call math. [Check out this link for postulates](_URL_0_).\n\nFrom postulates, we've collectively as humanity derived a set of *theorems* that can be proven from those postulates. Think of the \"proving\" step like a logic puzzle. You have a goal (the theorem you want to prove), you have a starting point (postulates), see if you can get from point A to point B. There are several other ways to prove theorems (induction, contrapositive, and I'm sure I'm forgetting others) as well, but they tend to be more advanced.\n\nSo, **TL;DR**:\n\n* Math in the real world is what happens when you take patterns in reality and make it abstract\n\n* Math works because the fundamental rules we assume to be true to prove everything are based entirely on our observations of the world that always hold to be true.\n\n* Math is the study of patterns and logic. All postulates are derived from patterns we as humans noticed out in the wild. They're rules that have always held.\n\n* We invented math, but we did not invent what math represents. Math is a language to describe our world in order to boil it down to the purest, simplest, most abstract terms. Much like how I can use the word \"apple\" to mean a particular type of fruit, math is the language of reality.\n\n* Math exists out of necessity. From the earliest days of bartering, we needed a way to say \"a = b\", \"a > b\", and \"a < b\". Going even earlier than that, we needed a way to say \"165 pounds of Gazelle, minus X pounds of bone, minus Y pounds of skin, is going to leave Z pounds of meat to feed 12 people. Is that enough for everyone?\"",
"Mathematics is about looking around you and seeing what the pieces mean. In math, you get the luxury of a starting set of hypotheses -- axioms, as the Mathematicians say -- and you then ask the simple question: if these are true, what else is?\n\nThis is in contrast to science where we do the experiment and find the end result, but can never know for certain what the starting axioms actually are. When, for example, Einstein crafted his theory of relativity he did some science in guessing what the axioms might be, and then did a lot of math by asking what the consequences were (and subsequently working them out). ",
"Mathematics is a language used to put meaning to the patterns which persist throughout every level of size we have discovered in our observable universe. These patterns are thought to exist on all levels because all living and non living masses are all in possession of varying amounts of the same energy on the most fundamental scale. The language uses measurements to generalize information about the quantities of forces, masses and their interactions and how they all fit together to produce what we humans consider to be the physical world. etc. (Distances, forces, masses, volumes, temperatures, pressures, the list goes on and on). All math is a description of whats out there in the universe. Math does not exist because the universe does exists, the universe is not dependent upon the math for its function and survival. The math is a creation of the human mind used to express what we are all actively taking part in every day and witnessing transform stars in the sky. Math is the human attempt and accurately describing real life things like motion in a way that is specific enough to be reproduced by nothing other than the math itself. The units are defined by the speaker as he/she interprets them, so long as that interpretation of the units is constant throughout the sentence, or equation. Math is always a description of something..... No college experience or diploma here, just my opinion of what mathematics is after a high-school math education.",
"*[Something To Let You Maintain Your Puzzlement](_URL_0_)*",
"Okay so I'm not a mathematician, but I've done and am doing and will be doing a considerable amount of mathematics in my degree plan, and this is *my* interpretation of what math is.\n\nIt's some thing we made up. It doesn't 'exist', the universe doesn't check for a table of constants, or make this chemical reaction happen at this speed because there are that many molecules, it just *operates*. We, being a curious species, use our own conceptualization of numbers to explain the things we see in front of us. Read this:\n\n_URL_0_\n\nPi is a very 'important' number - especially if you're going to study any kind of science, pi is something that you will eventually start to use in some way. Pi isn't a number that is engrained in the universe, it just IS - and the 3.1415 . . . is a number we 'found' because of the way we interpret numbers.\n\nI know we operate on a base 10 mathematical system and I think I read somewhere that it is probably because we have 10 fingers off of which to count on, which influenced our evolutionary understanding of numbers. I'm curious to know how much constants like pi would change if we were operating on a different base system, would it change at all? Would all of our mathematic laws of physics and nature change if we were using say, a base 6 system?",
"Math is a way of telling a story about something, even if you never get to see that something.\n\n\"Michael brought bread to the table. Marie, Don, Fred, and James had Michael's bread, but Michael and David were unable to have bread.\"\n\nThere's something about this story that illustrates something about the bread that allowed Marie, Don, Fred and James to have Michael's bread, while Michael himself and David couldn't have any. There simply wasn't enough bread for all of them.\n\nWith maths, we can answer some questions about why only some of the people at this table could have bread. We can imagine that there are a countable number of people at this table, that there is an amount of bread one of them brings to the table. Also there's a matter of distance. Why David and Michael went without bread instead of just Michael.\n\nSure, there are plenty of questions that can come up that don't have to do with maths at all. Maybe David has a gluten allergy and chose not to partake of any bread. And maybe Michael was too busy setting the bread on the table that he was not able to take a piece for himself. And if that answer satisfies the listener, the dinner scene can continue.\n\nBut some folks are really curious about details. And maths lets us look for details into why only some people had bread and others didn't. Was David too far away from the table to get there in time before all the bread was taken? Some maths can answer that. Why didn't Michael use one hand to offer the bread and use another hand to take a piece for himself? Some maths can answer that too.\n\nMaths allows us to look for details about events regardless if we can see them directly, and many of us are very curious about how things happen. Maths is something we formed and agreed upon to find a way to share these details, and even sometimes find out things we didn't even know.\n\nSome maths out there are for things we sense. Some maths involve things that don't really exist. And that gets to people sometimes. How can you talk about things that don't exist? It takes a great deal of wonder and patience and practice to do so, but sometimes those imaginary things will surprise you by being a great way to look at the details of things that are real.",
"Mathematics is simply a tool we developed in order to describe the patterns found in nature, and like all tools, we designed it to help us understand those patterns better. So technically, mathematics is man-made, but its creation is inspired by patterns and concepts that are not easily explained without a use of tool.",
"Math was a thing the Scottish invented to trick the British into lowering their taxes. \n\n",
"when i was in second grade i asked my teacher this same question. i wanted to know why math worked more than how it worked. she got really angry with me because she didnt know how to answer and thought i was being a smart ass. i got detention and gave up on math being and interesting subject until adulthood. i wish i had had reddit back then.",
"Math is abstraction, a way to describe or symbolize pretty much anything. It's like kids draw stick figure and put some random lines and say it's daddy. And from that point to try make it simpler, ie, cave man draw many copies of animals to record \"many\" without precise amount, after you invent numbers, you can simply say 25 elephants.\n\nIt works because it starts from symbolize physical things, ie 1 ship can carry 25 soldiers, so 4 ships incoming you have maximum of 100 soldiers attacking. You give symbols(+,-,x,/) for what they suppose to do in a formula, and later everyone agree to use it the same way for better communication. \n\nMath does not study anything, human study math as a tool, and use math to try describe other things, be it observable(how long does it take for Earth to orbit sun) or just hypothetical( how fast will zombie spread if T-virus is real), thus new symbols are invented to describe new concept of doing complex calculation but don't take many pages to write it down in pages like idiot.( ie, 5x100 = 5 + 5 + 5 + 5...... )\n\nWe invent math symbols, but discover relationships of how some formulas can accurately describe real world things. Math is here because we need a system to efficiently book keeping instead of painting 200 cows on a small sheet of paper, but at the end people need to study all those symbols and formulas that all the previous smart people discovered.\n",
"using symbols to represent everything we can count or measure and playin with them and shit like that",
"Math is logic, except distilled to a shorthand form that makes it easier to explain a logical thread of information. \n\nSometimes we interpret the math wrong, and draw further conclusions from a logical conclusion than we should. See the Financial Crisis.",
"Consider a set of statements that are so obviously true no one would argue with them. Statements like: for any number x, x * 1 = x. Or, for any number x, there exists a number -x such that x + -x = 0. These statements are called axioms. They're things we accept as true without proof.\n\nMath is the process of figuring out what more interesting statements could be made from the axioms. For example, from a set of 9 axioms about real numbers, we can prove that x * 0 = 0 for any number x. These more complicated statements are called theorems.\n\nThe axioms needn't describe numbers. For example, there are the seven (I think) axioms of origami, describing the seven different way to define folds of paper. And from these axioms, Robert Lang has been able to prove a theorem that simply stated says \"If you can draw a stick figure of it, I can origami it.\" He's created wonderful works of art based on this theorem. I encourage you to look up Robert Lang if you are interested.\n\nAnd that's math.",
"I don't know if this is ELI anything under the age of like 16 but that would take tons of time. If you actually take Calculus 3 or so (for some it is 2 or 1) everything just clicks. Math is no longer boring and weird but it is actual beautiful. You go past the numbers and you understand it you understand what it is used for and why. I went up to Calc 4 and stopped, but I am sure it gets even cooler if you go deeper but ti understand you have to take some calculus IMO.",
"We invented math to describe what we can see of the math that already naturally exists.\n\nMath is taking one and making it many. Tangling, twisting, and bending, with out ever violating the one.\n\nMath is taking many and unrolling them, smoothing them, stretching them. Making one without ever violating the many.\n\nMath is gazing in awe at none. The none that rarely is.",
"I always liked the following definition of Mathematics:\n\nMathematics is the symbolic representation of logic",
"I'm in high school and I do a lot of extra math competitions and tests. I lose sleep over this question. People consider me to be good at math, but what is it that I'm actually doing? I don't know for sure, but this is the best explanation I could come up with so far:\n\nReligion is a man-made explanation of how things work. We turn to it to know what happens when we die; early peoples used it to help in things like farming or sailing, as well. Science is also a man-made explanation of how things work, but it's more accurate and relevant than religion in many non-existential respects. We now generally rely on science to help farm and sail. Mathematics, however, can exist entirely within itself. Although it's most often used for science, certain respects may have no practical application.\n\nI consider there to be two different ways to think of mathematics. The first way is as a system of thought. From some small but highly applicable set of basic, concise rules, so long as you can make infinitely many deductions that you can prove to be true or false from only those rules, the rules compose a form of mathematics.\n\nThe second way is as a discipline. This is the arbitrary selection of such rules that society as a whole considers to be true. For example, if I were to write \"2 + 2 = 4\", you would most likely immediately recognize a true statement. But the truth of this statement is arbitrary. Society could have just as easily made it so that \"2 + 2 = 5\" was a true statement. Only because the generally accepted set of rules can prove that \"2 + 2 = 4\" is true do we accept it as such.\n\nAs for why it works, I have much less idea. There can be topics of mathematics that don't work (have no scientific application), but I find it amazing that so many of them do. Personally, I like thinking that a mathematical universe is a requirement for intelligent life. I think that the Einstein quote sums it up best, though:\n\n > \"The most incomprehensible thing about the universe is that it is comprehensible.\"\n\nEdit: format",
"I've often asked myself this and and this is how I see maths. \n\nMaths is a language like any other, and is used for communicating ideas. What sets it a part from other languages is the precision it has in it's rules and definitions. \n\nLanguages need common understanding for communication to take place. Take English and I want you to pick up a phone. I could say 'pick up the phone' but that relies on both of us having a common frame of reference eg. what a phone is and what pick up means and so on. I don't need describe what a phone is and what all the elements of science tht make up the 'pick up' motion\n\nIn maths it's the same but the rules are be defined from a very very basic set of assumptions or very simple frame of reference (called axia) . Maths then defines the things based on these (both objects - like the phone in the above example) and processes (like pick up) to add more and more complexity. \n\nSo far it's like any other language and is used as a tool to communicate ideas about the world (both real and imagined). The big advantage is that because it's made up of so many smaller element s many of is components it has can be applied in many different ways to come up with completely new ideas, or new ways to express existing ones.\n\nI studied physics (high school) and it was at that point maths as a language became clear. Physics models (describes) reality at a very low level. It needs a language that describes it's ideas in a very precise way and this is where maths helps. You see something in the real world that has some properties that change (ice into water for instance). If you measure accurately enough you can plot some numbers that will give you a graph of the change. So now you have something real that is described in maths (a graph), and you can look at the data and say \"oh that's looks like an foobar function\". Then a maths expert could look at that an say - did you know foobar functions that have a starting point of 10 will always do something special. You can now look at you real world and think about what if your property started at 11 - would the property have done the same - what would if mean for the world if you did?\n\nAll I'm trying to convey is that it's a language that helps describe the world in a way that's useful to some people. It's like a very precise poetry.",
"One of my (computer science) professors in college described math as a modeling language. I've yet to come across a more concise definition.",
"Math is the observation of patterns. Essentially, it is a language to represent how everything works with absolute certainty.\n\n > Did we discover math or did we invent math?\n\nWe invented the symbols that we use (numbers, operations etc..) as \"markers\" for the ideas we discovered. For example, whether you refer to a single unit of measurement as \"one\" or \"1\" or \"uno\" is irrelevant; it doesn't change what is being represented.\n\n > What is math in the real world?\n\nA computer program can emulate reality and to do so, everything needs to be logical. Fundamentally, events occur as the result of IF\\THEN\\ELSE, as in, if x=1 then [do this] else [do that]. \n\nRegarding the \"real world\", the reason artificial intelligence is deemed to be impossible by some people is that we observe reality through the proverbial right side of the brain, where events happens more chaotically and *without* a line-by-line sequence of rational conclusions. We can make mistakes and not know why, whereas a simulation (in regards to being the opposite of reality) would have a very specific reason as to why something happens (such as an error in the coding).\n\nI think understanding how computers do what we want them to do is a great parable to seeing how math applies to everything around you. If you really want to get deep on the idea of what math is and how it really is a representation of everything, check out the concept of [simulated reality](_URL_0_).",
"In some ways this can't be an ELI5 without lying a little bit. Just recognize that this is very incomplete.\n\n Math is a lot of statements that you can make. Not a language by the way as some have said here. The symbols we use to communicate those statements are a language. But we could choose different symbols (different language) and it would reference the same statements. Anyways, whenever someone makes a statement in math you can ask them why that is true and they will explain it using other statements. You can keep asking why, and eventually you will get to a few statements that are just assumed to be true. These statements at the bottom of the tree of asking why are called \"axioms\".\n\nWhat pure mathematicians do is to work this process backwards. Start with the axioms, and build the trees from those. What we see is just the outer branches and leaves but all of that really springs from statements that lie at the bottom of the trees, even though the useful stuff is up top.\n\nAs for \"why does it work\". I hope this isn't a copout, but that is not really a valid question in my opinion. There is no why. They do work, insofar as we have picked our axioms wisely. In other words, we have chosen the right place to plant our tree and grow it out (sorry, I'll leave that metphor alone now). We appear to have done so.\n\nAnd let me emphasize again, this is all much more complicated than I'm letting on. And this is also not quite what I do for a living, so I might have missed some important stuff even at this basic level.",
"I've always found this picture to be helpful _URL_0_",
"Put simply, **math examines how and how much things are in relation to each other**.\n\n* How big a slice of cake needs to be when a certain number of people share (arithmetics)\n* How hard you must throw a ball for it to reach your team mate, the curve it describes, the way it travelled (integrals)\n* How big the chance is of you winning the lottery with a given number of tickets and players (statistics), or [how to behave in a game show](_URL_0_)\n* How the roof on your house must be angled for it not to be crushed by snow in the winter ([differential analysis](_URL_1_) among others), and how the angles are constructed by using lengths instead of angles (trigonometry)\n* How your optimal way of playing is when you play Risk with your friends (game theory)\n\nAnd while those are real-world examples of how quantifyable things can stand in relation to each other ensuring that math can be applied, **you can apply math to math** - and that's where it got really useful, as this allowed us to go beyond immediately observable relations and find out what the \"big\" connections may be, those that we can't see.",
"IMO, **mathematics is the pursuit of [Analytic Truths](_URL_0_) through dialectic means**. An Analytic truth is anything that is completely independent of the \"real\" world, what most would call the physical world (If you don't agree with the philosophical concept of [materialism](_URL_1_), then there is more to the real world than just the physical. For example, if souls and god exist as actual things and not just ideas, they count as part of the \"real\" world, even if they aren't objects). Any analytic truth is true because of what the words or symbols mean, not becuase of anything to do with the world. 1+1=2, and it would still equal two (as long as those symbols mean the same thing) if the real world were completely different in every way, or even if there was no universe and nobody to think it. By contrast, a Synthetic Truth is something whose truth relies on the real world. So \"All bachelors are married\" is a synthetic truth because it's true because of what the word bachelor means. It's kind of a trivial example, but that statement is an example of math. The statement \"Atmosck is a bachelor\" is true because of the fact that I, a part of the real world, am not married. \n\nWhen I say \"through dialectic means\" I mean as opposed to empirical means. If you come across a fact just by thinking about it (as is the case with math, or at least when a piece of math is originally discovered), you've discovered it through dialectic means. If you discover something using your senses (as is the case with all of science), then you discovered it through empirical means. Science is all about the real world, so **Science is the pursuit of Synthetic Truths through empirical means.**\n\nAdditionally, **metaphysics is the pursuit of synthetic truths through dialectic means**, and you could argue that most of philosophy falls under metaphyics or meta-questions like whether this is possible at all (or if any knowledge is possible at all). It's a popular view these days that metaphysics is impossible. But as an example, the [Ontological Argument for the Existence of God](_URL_2_) is supposed to be a dialectic argument (because it only relies on definitions an logical truths) with a synthetic conclusion (that god exists, in the real world). (Arguments that the ontological argument is faulty usually rely on the analysis that it has implicit empirical assumptions that are faulty.\n\nTo answer some of your questions directly, the truths of maths are things we discover, by reasoning. What truths of math we try to figure out are often motivated by the fact that they are often useful analogies for the real world. For example, given the rules of geometry, the facts of geometry would be true in any universe. But the reason we care about geometry with those particular rules is that we can describe our world in terms of that geometry. Often we change the rules just to see what would happen (what if a line had multiple different parallel lines that go through the same point) and study them just because they're interesting, and later find out that they are useful in science somewhere.\n\n**tl;dr** Math is figuring out, just by reasoning, things that are true and would be true no matter what the real world is like (you could never make 1+1=2 false just by changing things about the universe).\n",
"A long time ago, humans found they needed a way to keep track of quantities, and started counting things. This was step 1.\n\nEventually they realized they wanted to remember what they had counted, and decided to use symbols to write things down. This was step 2. Several systems came and went, but it's important to remember we invented the idea of numbers and how they get written down.\n\nUp to this point, really no math was being done. Most of the math you do in grade school to deal with addition and subtraction isn't so much real \"pure\" math, it's just learning the system of dealing with those symbols we made up. (Think of carrying the 1, and the idea that when you have 12 things it's written as a '1' followed by a '2', etc.)\n\nWhere real math started was when someone had to figure out how to invent that system that we now call 'numbers', and when someone had to make sure that set of rules we invented called 'arithmetic' are actually guaranteed to work. After all, we don't want to adopt a system of numbers only to find out that it breaks down in some odd unforseen case. So early mathematicians proved that 'arithmetic' works for our arbitrarily invented system called 'numbers', and by doing that in a very rigorous and specific way, they were able to prove 100% beyond any possible doubt that arithmetic is a valid way to work with numbers.\n\nInitially they started with addition and subtraction. Makes sense, you have some things over here and some things over there, and you want to put them together or separate them apart. But then, those early mathematicians realized that certain kinds of addition were repetitive, and quickly found that if you know 100% for sure that addition works, then another rule naturally arises that makes those scenarios much easier. They called it 'Multiplication' and proved that if addition is valid, so is multiplication.\n\nAnd so it went from idea to idea. Someone realized that because we know addition and multiplication are proven to be true, they could prove that you can work with numbers even if they're unknown, and algebra was born. Society needed to work with shapes, and since they knew arithmetic and algebra are proven to be true, they can use it on shapes. Geometry and trigonometry were born. Then they realized that since geometry is proven valid, there was a way to use it with lists of numbers, or continuous functions, and went about proving that Calculus is a valid way to work with numbers.\n\nSo, this is how society has used math, and what math has been to society, but it's not the best answer for \"what is math\". I went through that explanation because if you look closely there's a repeating pattern going on.\n\n**Math is the mental process of proving that something is 100%, absolutely known to be true.** (Within any constraints set by your initial assumptions.) It's frequently used to discover new ways of dealing with the world because \"if we know A and B are true, I can prove that C is also true.\"\n\nI went through all that explanation above because, without it, it could be hard to understand what that statement means. In the context of \"We had figured out that you can add numbers, and someone used math to realize that multiplication is a thing\" it makes more sense.\n\nDoing math depends on the discipline of being able to work with abstract ideas, and keeping good track of your initial assumptions. For example, as many people who played old NES games may have noticed, addition doesn't work when you're working with 8-bit binary numbers. If you add 100 to 200, you get 44. This happens because when binary numbers are limited to 8 bits, that disobeys one of the fundamental \"ifs\" that were in place in proving the validity of arithmetic. (Basically, you can't ever have a situation where if you keep adding 1 to your number you end up back where you started. Unsigned 8-bit binary numbers wrap around when you go past 255, so you can only use arithmetic on them if you avoid that situation.)\n\nIt also depends on the discipline of understanding that math happens in the abstract and not the real world, and making sure you're using a valid translation of math when you use it in real world scenarios. For example, I can't \"prove that math is wrong\" by showing that if you add one rock to one rock really hard, you get three rocks since one broke. That's not math being invalid, that's me (deliberately) applying it wrong. I started with the assumption that my rocks were indivisible units when I counted them as \"two\", and then broke that rule. This discipline is called \"Applied Mathematics\" because you're deviating from the realm of abstract ideas that work the way they were intended with no strings attached, and entering the realm of real things that behave according to the rules of real life. (e.g., if I tell you I have the number 1 but I need the number 2 so I'll break the 1 in half to get two 1's, you will easily tell me I'm doing it wrong. But if I tell you I'm going to break one rock into two rocks, your mind has no objection to that phrase.)\n\n**The TL;DR**:\n\nMath is used to prove that things are undeniably true. That's really the only definition that fits everything math does. Math is made entirely of things we invented, all the way down to numbers and the idea that adding 1 to 9 is 10, and adding 1 to 7 is not 10. Math works only on abstract concepts, until you choose to apply it to the real world, at which point the only flaws you have to worry about are any flaws in your logic of how you applied it to your real-world situation.\n\n[Edit] I foresee someone pointing out that this doesn't sound like what they do when they're \"doing math\". My counterpoint would be, you're not \"doing math\" you're \"doing arithmetic\" or \"doing calculus\". We as a culture just don't feel like splitting it all apart and talking in such annoyingly precise terms all the time, so we say \"Doing Math.\"\n\n[Edit 2] Why does it work? It works because it's been rigorously proven, and because it ultimately only depends on abstract things that we made up. Calculus works because geometery and algebra work, those work because arithmetic works, and arithmetic works because our system of numbers follows certain rules. Everything has been rigorously proven every step of the way, making all of it a complete pure certainty. (At least, until someone tries to apply it to the messy, unkempt real world.)",
"I like math- I might have something to add here....\n\n...reads commments...\n\n...I have nothing to add here",
"The universe is made of two things: matter and energy.\n\nMatter is stuff.\nEnergy makes the stuff move.\n\nWe created math to predict where \"stuff\" will \"move\" before (or after) it happens. ",
"We do not have good memory, but when we write something down, it allows us to keep note of it. As problems in everyday life became more and more technical, (like figuring out how to divide pieces of land in Babylonia) writing symbols down to keep track of our technical thoughts became the only way to easily solve these problems. As this became more commonly used, we started to develops a system around these symbols so people would not need to re-learn another's symbols every time they were looked at. This is what math is. It is a highly technical language that allows you to short cut writing out long sentences. Just like we use our thoughts to think through something, we also use those same thoughts for communication to others. Some one doing math could be thought of as thinking their way through a technical question instead of a literal one. This has extraordinary practical applications to modeling the physical world. Hope that helps.",
"1+1=2\n\nAnd everything else is just built up on top of that, because those numbers can mean anything.\n\nSubtraction is just the logical \"well that means that 2 - 1 = 1\"\n\nMultiplication is just rewriting that same thing. Technically the meaning of 1+1 is the same as \"hey, put 2 of that 1 together\". Rewrite it as 2 x 1 = 2. \n\nDivision is the opposite of multiplication.\n\nAlgebra is just saying it doesn't matter what the 1 represents. Heck, it could represent another number if you want. 1(apple) + 1(apple) = 2 (apples). rewrite that as 1x +1x = 2x. Or, if you want, write 1(3) + 1(3) = 2(3). Which conceptually is the exact same thing as writing 3 + 3 = 6. And that's basically just multiplication again. Doesn't even matter what it represents.\n\nEverything, all the way through calculus and the ends of our mathematical knowledge is just messing with these facts, and they all rely on a really really simple premise that 1+1 = 2. ",
"There are a lot of good answers... but nothing that seems geared for ELI5 that I've yet seen. So I'll give it a stab. \n\n\nImagine that the universe is actually a simulation - on a computer. \nWe exist within this simulation, but do not know the code that defines our reality. \nMath is us reverse engineering that code. The code *library* to be more precise. \nThe generic goal is to understand the 1 and 0s behind it all. \nBut we more often seek different high-level syntax's, which make some topic easier to deal with. \nPhysics, in this analogy, is the goal of understanding some existing bit of programming within the context of that syntax. \nAnd engineering is the use of that syntax to create something ourselves. \n\n\nThat said, we make up our own syntax. We lack access to the real library, and thus must create our own. So when people say that math is man-made that is what they mean. But it doesn't change the fact that what it is used to define is very real, and exists as *truth* regardless of our accepting it. ",
"OP, I actually find this question, and questions like it, to be profound and thoughtful. It's one of those big Why questions. Most people don't ever think to ask things like this. Good for you.",
"Math is just a series of logical arguments.",
"Not really an ELI5-answer but I liked the video the Idea Channel did on this subject on youtube [Ideal Channel](_URL_0_)",
"In physics we have found a way to predict the behavior of objects (like planets for example).\n\nTo each object you associate a number m, the \"mass\" of the object, which you can think of as corresponding to how difficult it is to accelerate the object.\n\nWhenever something is pushing on something else, we introduce a vector (a quantity with both magnitude and direction, which can be described by three numbers) which corresponds to how hard the thing is pushing, and also the direction in which it's pushing.\n\nPhysicists have found that these quantities can be given appropriate values such that equations such as the following are satisfied:\n\n-- F = ma (F is the total force on an object, m is the mass of the object, a is the acceleration of the object).\n\n-- If A pushes on B with force F, then B pushes on A with force -F.\n\nWith this approach, we can write down some equations that describe how a physical system (like a bunch of planets orbiting the sun) behaves. By solving these equations, we can predict how the physical system will behave in the future.\n\nThis is only one example of a \"mathematical model\". Mathematical models like this are used throughout physics, science, and engineering. The equations in the model may not actually be satisfied exactly, but hopefully they are close enough to being true that the model predicts reasonably well how the system will behave.",
"A lot of very smart people have been thinking about this for a long time. It is not assumed to simply be the \"science of patterns\". No five year old is going to have a clue about any of this (unless they spent like, 10 years working on it, at which point they would be 15. If my *math* is right). This might almost read as nonsense if you don't have a little background. There's probably an introduction to phil of math on youtube or something that would be better.\n\n\nFrom ( _URL_0_ ):\n\n > 1.Logicism\n\n > The logicist project consists in attempting to reduce mathematics to logic. \n\n > 2.Intuitionism\n\n > Intuitionism originates in the work of the mathematician L.E.J. Brouwer (van Atten 2004). According to intuitionism, mathematics is essentially an activity of construction. The natural numbers are mental constructions, the real numbers are mental constructions, proofs and theorems are mental constructions, mathematical meaning is a mental construction\n\n > 3.Formalism\n\n > David Hilbert agreed with the intuitionists that there is a sense in which the natural numbers are basic in mathematics. But unlike the intuitionists, Hilbert did not take the natural numbers to be mental constructions. Instead, he argued that the natural numbers can be taken to be symbols. Symbols are abstract entities, but perhaps physical entities could play the role of the natural numbers.\n\n > 4.Platonism\n\n > In the years before the second world war it became clear that weighty objections had been raised against each of the three anti-platonist programs in the philosophy of mathematics. Predicativism was an exception, but it was at the time a program without defenders. Thus room was created for a renewed interest in the prospects of platonistic views about the nature of mathematics. On the platonistic conception, the subject matter of mathematics consists of abstract entities.\n\n\nI think that in practice most mathematicians are platonists, if they even care about the issue at all. You don't need any of this to do most mathematics. It reminds me of Richard Feynman's quote about philosophy of science. “Philosophy of science is about as useful to scientists as ornithology is to birds”.\n\n\n",
"This question is a very deep one. The article linked below gives an interesting example. The first paragraph is a fun one. You can ignore the statistics jargon and get the full effect I think.\n\n_URL_0_",
"So this is a contentious topic. I'll start by explaining the logicist view and then suggest some problems with it.\n\nOne view is sees Mathematics as logical extrapolations from a set of axioms (assumptions). For example, Euclid's elements, which contains proofs of many of the basic theorem's of geometry (e.g. Pythagoras' theorem), arrives at these proofs by starting with a set of axioms. One such axiom is the [parallel postulate](_URL_1_), this axiom can't be derived from the other axioms Euclid uses. We might consider such an axiom to be (at least an approximation of) a fact about the real world, but nonetheless it is important that this axiom (like Euclid's other axioms) is not provable a priori.\n\nHowever, it may be possible to prove such axioms from some other, more basic set of axioms. Indeed, we might expect that the axioms that define integral and differential calculus can be proved from the axioms that define basic arithmetic and set theory. Showing this to be true would be no simple exercise.\n\nSuch a view of mathematics suggests that all of math could be described using some very basic set of axioms and then using deduction rules to arrive at more complex theorems.\n\nA deduction rule is a concept in formal logic. The idea is as follows: normally you might informally deduce something e.g. \"look, we know if John goes into the cinema then Stacy will go too. Well John is indeed in the cinema, therefore Stacy must be.\" By contrast, in formal logic you carefully define a set of formal rules that determine what sentences in your logical language follow from what other sentences. So one rule might be that a sentence of the form \"A if B\" and a sentence \"B\" together imply \"A\" (this is equivalent to the cinema deduction). In reality we use symbols rather than words but that is the basic idea. For some types of formal language and associated deduction rules we can check whether those rules are consistent (they never lead to a contradiction) and that they are complete (if one conclusion does indeed follow from a set of premises then it is possible to get from those premises to that conclusion using our deduction rules). Once a proof is written in this way it could be easily verified by machine whether the proof is valid.\n\nThe project of carefully defining mathematics in a formal language and deriving formal proofs using the deduction rules of some formal logical language is known as [logicism](_URL_0_) and gained momentum at the end of the 19th century. Thinkers like Bertrand Russell championed the project which had been initiated by Frege and Dedekind.\n\nThere are however a number of problems that face locisists. Firstly, Godel's incompleteness theorem shows that regardless of how you set up your formal logic version of mathematics (i.e. no matter how you set up your axioms and choose your deducation rules) for any system that could be used to describe even basic arithmetic, the system you set up can never be both consistent and complete, i.e. there will always be some true statements that your system cannot be used to prove to be true. This is not necessarily a rebuttal of logicism but it perhaps limits what logicism might hope to achieve.\n\nGodel's second incompleteness theorem also presents a challenge, it effectively implies that you can never prove that a formal system that includes basic arithmetic truths is actually consistent. This arguably answers your second question \"why does it work?\" the fact is it might not. We cannot formally prove the consistency of math, it is possible (if highly unlikely) that tomorrow someone could prove one thing and then prove the opposite of that thing is also true and hence destroy our entire conception of mathematics.\n\nThere are also deeper problems for logicism. Chiefly there is an argument that logical systems presuppose ideas about the natural numbers in the way those systems are set up. That the concept of numbers of things is built into the structure of logic, by talking about \"A and B\" perhaps we are presupposing a concept of 'twoness'. It has been argued that the essence of math is the natural numbers.\n\nThis is an ongiong debate and a very interesting one. Clearly logicism has had some major victories, it is likely true that at least a decent majority of mathematics could be derived formally from the basic axioms of set theory. But whether this such a view of mathematics would actually capture its essence is less clear.",
"Let me begin by saying that by *mathematics* I will not mean that which is taught at school. I don't know what that symbol-pushing, pattern-matching, number-crunching, soul-crushing thing is, but I know it is not mathematics.\n\nMathematics, as practised by us humans, is, quite simply, reasoned imagination. Nothing less. Unlike the other art forms, say poetry, it is not constrained by the universe, which is merely a particular kind of semi-riemannian manifold. \n\nWe mathematicians study manifolds, CW-complexes, varieties, schemes -- all vast generalisations of the notion of physical space. We(or at least Gromov) deal with spaces where each point itself is a Riemannian Manifold. We deal with an infinite sequence of CW-complexes all tied together in a strange dance, called Spectra. We routinely deal with spaces of infinite dimensions (hilbert space) -- in fact, a quantum system is a point moving through this space described by what is called a wave equation. \n\nWe study mathematical structures and objects, which are built up from axioms. However, mathematics is no more a game with axioms than music is a game of squigly marks on sheets of paper. What are mathematical structures and objects? Well, they are what mathematicians study. Let me explain by way of an example -- when Euler solved the Konigsberg Bridge problem, he did not think he was doing mathematics, but his solution and the subject he initiated is now a card carrying member of mathematics. The object he used in his solution, a Graph (I feel forced to call it a one-dimensional CW-complex), is now a mathematical object par excellence. \n\nThere are some who believe that capital R Reality, ultimately, in the end, at the very bottom, sub specie aerernitatis sort of a way, is a mathematical entity (which is frankly not as crazy as it sounds -- begin by thinking about Rutherford's experiments, escalate to a textbook on QFT). \n\nSo, the real question is not what is math in real world but where is the real world in math?\n\n\n**Edit** I am infering, from many of the answers given, that a lot people seem to be approaching this question from a CS or philosophy background (That 'model theoretic' answer of mhd-bhd reminded me of an undergrad logic class I had taken long ago). However, I just wanted to add that it is safe to say the majority of the (pure math) community do not view mathematics like this, but having said that I'm not sure how much that really matters actually.\n\nI just wanted to add that the 'axiomatic' way is just how we package our math. And although we care about 'proofs' and 'theorems' a lot, what we are really after is 'understanding' -- this is why we try to prove a significant result in as many different ways we can. As mathematicians we are trying to get the right concept or idea which we encode as a 'definition'. We are interested in proofs not just because of the certificate of certainty that they gives us, though that is important as well, but because they help us understand the mathematical landscape. ",
"I can't believe no one has pointed out that the definition of math and its relation to the material world (or what you might call *reality*) is [a whole branch of philosophy](_URL_1_). There are several interpretations on which level math operates: does it only live in our imagination, is it a brain function or is it even(identical to) nature? For an easy introduction you might be interested in [this video](_URL_2_) and [this](_URL_3_) and [that one](_URL_0_) gives you an idea about where the problems are on relating math to reality.",
"It's a model for the logic of reality. We know it works because we observe it working.",
"On the surface this may seem like a 'stupid' question to some, but this is a fantastic example of what ELI5 should be all about: explaining complicated topics and concepts that don't necessarily have a readily apparent answer. The philosophy of math is really cool.\n\nI've stickied this post to the front page as an experiment to see if we can encourage more thought-provoking content like this.",
"[There is no one answer for this.](_URL_0_) Simply put, mathematics is a system we use to model our universe. It stemmed from the dawn of humanity from tangible objects; we count in base ten because we have ten fingers and ten toes. So it's a model. We use addition to represent accumulation, and multiplication as a scaled up version of addition.\n\nThat said, there are also constants in math. Truths. Do numbers exist on their own? That is debated as well-- I'd recommend [this numberphile video](_URL_1_) which draws on the subject. We have values, like pi, e, and other constants and ratios that have a deeper meaning. Patterns emerge, and the numbers take on a life of their own. Math is a model for our universe, but it's also much more. I could elaborate on this subject for hours.",
"\"Mathematics is the language in which God has written the universe.\"\n\n* *Galileo Galilei*, Italian astronomer & physicist (1564 - 1642) ",
"Mathematics is really just logic, written with fancy symbols and equations. But it all boils down to very simple things that every human being, even children, can understand.\n\nOne of something is more than none of something. If I have one of something, I can't give it to you and still have one of something myself. \n\nFrom very simple observations like this come, eventually, algebra, calculus, and everything else."
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[
"http://en.wikipedia.org/wiki/Topology",
"http://en.wikipedia.org/wiki/Zermelo%E2%80%93Fraenkel_set_theory",
"http://www.abstractmath.org/MM/MMFuncSpec.htm",
"http://en.wikipedia.org/wiki/Stokes'_theorem",
"http://en.wikipedia.org/wiki/Abstract_algebra"
],
[
"http://en.wikipedia.org/wiki/Mathematical_logic"
],
[
"http://www.jcrows.com/withoutnumbers.html"
],
[],
[],
[],
[
"http://library.thinkquest.org/2647/algebra/post.htm"
],
[],
[],
[
"http://www.youtube.com/watch?v=TbNymweHW4E"
],
[
"http://en.wikipedia.org/wiki/Pi#History"
],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[
"http://en.wikipedia.org/wiki/Simulated_reality"
],
[],
[
"http://i.imgur.com/Vqo79.png"
],
[
"http://en.wikipedia.org/wiki/Monty_Hall_problem",
"http://en.wikipedia.org/wiki/Structural_analysis"
],
[
"http://en.wikipedia.org/wiki/Analytic%E2%80%93synthetic_distinction",
"http://en.wikipedia.org/wiki/Materialism",
"http://en.wikipedia.org/wiki/Ontological_argument"
],
[],
[],
[],
[],
[],
[],
[],
[],
[
"http://youtu.be/TbNymweHW4E"
],
[],
[
"http://plato.stanford.edu/entries/philosophy-mathematics"
],
[
"http://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.html"
],
[
"http://en.wikipedia.org/wiki/Logicism",
"http://en.wikipedia.org/wiki/Parallel_postulate"
],
[],
[
"http://www.youtube.com/watch?v=u7Z9UnWOJNY",
"http://en.wikipedia.org/wiki/Philosophy_of_mathematics",
"http://www.youtube.com/watch?v=TbNymweHW4E",
"http://www.youtube.com/watch?v=JmyLeESQWGw"
],
[],
[],
[
"http://en.wikipedia.org/wiki/Philosophy_of_mathematics",
"http://www.youtube.com/watch?v=1EGDCh75SpQ"
],
[],
[]
] |
|
odc57
|
birth control statistics (nsfw)
|
I am actually asking this is a volunteer counsellor at a teen clinic. I've asked around but nobody seems to understand what the following statistics genuinely mean.
Let's say birth control pills are advertised as being 99.8% effective with perfect use. How exactly is that percentage determined? If I'm a girl who has sex once a month then obviously I am MUCH less inclined to get pregnant that a girl who has sex 100 times per month.
Where does this number come from?
Likewise, perfect condom usage is also 99.8% effective. What accounts for that .2%? Can sperm pass through the latex?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/odc57/birth_control_statistics_nsfw/
|
{
"a_id": [
"c3gcg2l",
"c3gcjz0"
],
"score": [
2,
9
],
"text": [
"I believe contraceptive statistics are quoted as \"pregnancy per year given perfect usage.\" So 99.8% effective means 2 out of every 1000 women using the pill correctly will get pregnant within a year despite perfect use.\n\nOf course this makes a lot of assumptions. \"Perfect use\" is hard to achieve. Maybe a woman was busy that night and forgot to take her pill. Maybe she wasn't able to get a refill before the pharmacy closed that night and had to take it the next day. The biggest problem is a lot of people don't know how to use condoms correctly or use them inconsistently.\n\nYou get at another assumption and that is \"average use.\" They assume an \"average\" rate of sexual intercourse. I believe it's 2-3 times a week or something. Obviously the rate would be a bit higher for those with more active sex lives.\n\n > What accounts for that .2%? Can sperm pass through the latex?\n\nI believe condoms are less effective than 99.8%. The Wiki says 98% given perfect use, 82%-90% given typical use. As you can see, **proper** usage is a definite problem. The problems likely come from what I mentioned above. Improper usage which leads to breakage, and not using one every time. It's a great method since it also protects against STDs which almost no other method does, but is not a very good long-term solution if you expect regular encounters. Condom + a different form is probably your best bet for your overall health.",
"The birth control failure rates you usually see quoted are derived by what's called the Pearl Index if you want to look up more details. The number people usually quote is roughly an estimate of the number of unintended pregnancies over 100 women-years of use of a particular method. So if it was 1% failure (99% effective) then if you took 100 women and had them all use the method for 1 year, then 1 of them would be expected to have an unintended pregnancy.\n\nSo it's important to note it isn't a \"per-use\" statistic. Although of course if you have more sex than the average person in their study you are obviously at higher risk, it doesn't mean you have 1% chance of getting pregnant each time you have sex. (Otherwise a person on 99% effective contraception, having sex each night would very likely be pregnant after a year.)\n\nTo work out how the statistics would be affected by someone having sex significantly more than the average you'd have to look at individual studies.\n\nTo answer your question \"where does the failure rate come from?\":\n\nYou obviously know about \"Perfect-use\" and \"typical-use\" rates, a perfect use rate is determined on a study where the rules of use are rigorously followed, whereas a typical-use study has people use the method as they would if they were left to their own devices. Now obviously there's still some room for error in the perfect-use camp, even if people are told to rigorously follow rules, they're only human. Some of this can be statistically accounted for, but other things account for part of the failure rate. Other factors to consider are manufacturing defects, condoms can be made with defects, pills can have imperfect manufacturing too, these factors contribute to the failure rates.\n\n\nSorry this answer has been some vague, but really the problem is these statistics are often very specific to the circumstances of the individual study, without looking at the details thats the best you can do.\n\n**Edit:** One more thing, I always think a useful statistic is the \"failure rate\" of nothing. Its approximately 85%, so after a year of having sex without any protection, 15% of women still wont be pregnant."
]
}
|
[] |
[] |
[
[],
[]
] |
|
1uo5ub
|
how are secret formulas legal?
|
For instance, products such as WD-40 do not list ingredients. Coca-Cola simply lists "flavoring" for some of their ingredients. How do we know such "secret ingredients/formulas" are safe and how does the government go about regulating these formulas? Is there a reason that this IS a legal practice?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1uo5ub/eli5_how_are_secret_formulas_legal/
|
{
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"cek2ag0",
"cek4hwd",
"cek63du"
],
"score": [
5,
2,
2
],
"text": [
"There are certain ingredients which are banned, and that can not be used in any capacity. Since the creation, importation, transportation, and use of these ingredients are strictly regulated, there is little fear that they are going to end up in consumer products, especially major ones that many people use.\n\nSo the government focuses on testing the product itself, rather than what's in it. Things like the [technical data sheet](_URL_0_) are compiled, determining the product's features and the risks associated with using it.\n\nSame thing, Coca-Cola has to submit to quality controls, and they have to have their sugar and caloric content independently verified. But as for what's in it, they don't really care. ",
"Foods and drugs are regulated differently than chemical concoctions like WD-40. If you have access to a mass spectrometer, it would probably be a short bit of work to work out what it's made of. Likewise, you can legally knock off any perfume with the same process. \n\nWhether something is legal or not can come from two approaches: legal unless proven harmful, or illegal until proven harmless. We take the former approach, because the latter approach is extremely costly, even for the things that're harmless. That cost limits the development of new drugs.\n\nThe FDA has had a long list of items that it has banned, time and resources permitting, that were commonly used as medicine. That's why you don't see Paregoric or Mercurochrome around even though these were common medicines in the past. Tylenol/acetaminophen might end up getting banned someday because of its \"narrow therapeutic window,\" the very small range of safe dosages for the drug that has come to light.",
"Things like WD 40 have something called an MSDS (material data safety sheet) that you can obtain by calling the numbers on the back of the can or emailing the company. (They reciently changed the names a bit and some of the label requirements - we just got retrained at work) They're required to list all chemicals that are potentially hazardous but there are materials called \"trade secrets\" that have no effect on the actual dangerous chemicals other than color or scent (such as the 'tide smell' that we all know). They don't have to list them because they aren't hazardous."
]
}
|
[] |
[] |
[
[
"http://wd40.com/files/pdf/wd_40tec16952473.pdf"
],
[],
[]
] |
|
971lye
|
how does augmented reality graffiti work??
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/971lye/eli5_how_does_augmented_reality_graffiti_work/
|
{
"a_id": [
"e44svng"
],
"score": [
2
],
"text": [
"Augmented reality is a catchall term for the use of computer graphics overlaid on our view of the real world. A live video stream can be edited to include artificial elements, or people might look through a clear screen that displays such things to the viewer. In practice this can be a symbol such as a QR code which a computer recognizes and then places a graphic over within the pictured scene.\n\nThis can be used to produce \"augmented reality graffiti\" because the artificial graphic can be made much larger than the QR code which triggers the overlay. A small mark on a storefront could trigger AR viewers to overlay a massive graffiti graphic which obscures the entire storefront for example."
]
}
|
[] |
[] |
[
[]
] |
||
2nbjaz
|
where did this "explain it like i'm 5" saying/concept originate?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2nbjaz/eli5_where_did_this_explain_it_like_im_5/
|
{
"a_id": [
"cmc4c7n"
],
"score": [
2
],
"text": [
"_URL_0_\n\nIt's from the Office."
]
}
|
[] |
[] |
[
[
"http://vimeo.com/27060669"
]
] |
||
2h08xg
|
Does any plant grow fast enough to be able to see the plant grow?
|
Plants like Chinese bamboo and Kudzu grow super fast. If you sat and watched the plant could you see it move? On an episode of Bones and body was wrapped in Kudzu and while in the lab the plant would move. The show has done a good job keeping facts straight but has fictionalized a lot of facts as well.
|
askscience
|
http://www.reddit.com/r/askscience/comments/2h08xg/does_any_plant_grow_fast_enough_to_be_able_to_see/
|
{
"a_id": [
"ckoaoit"
],
"score": [
3
],
"text": [
"As I understand it, if you were very very patient, yes you could perceive the growth of some of those bamboo. I don't know of any other plant that grows that fast. Some algae might be able to in the right conditions. "
]
}
|
[] |
[] |
[
[]
] |
|
vr3iy
|
The Homestead Act of 1862
|
I was watching something on the History Channel and they briefly mentioned the Homestead Act. Under the Homestead Act, a person had to apply for the title of the land, live there for 5 years, and show that they have improved the land.
My question is how did owners show that they have improved the land and how would the government know that the owners have improved the land (did they send some "agents" to authenticate the improved land)?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/vr3iy/the_homestead_act_of_1862/
|
{
"a_id": [
"c56yrm9",
"c56zs5d"
],
"score": [
3,
2
],
"text": [
"It referred to building a home, setting up the land for farming, adding additional irrigation, etc. ",
"\"There was no systematic method used to evaluate claims under the homestead acts. Land offices relied on affidavits from witnesses that the claimant had lived on the land for the required period of time and made the required improvements. In practice, some of these witnesses were bribed or otherwise colluded with the claimant.\" source: [wikipedia](_URL_0_)\n\n"
]
}
|
[] |
[] |
[
[],
[
"http://en.wikipedia.org/wiki/Homestead_Act#Fraud_and_corporate_use"
]
] |
|
2u9cgd
|
why is the crown victoria so popular within the police forces in north america?
|
It is a heavy, not so fast and probably not very fuel efficient.
It is my favourite car of all time, but i just can not grasp why they would use it over e.g. a Dodge Charger.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2u9cgd/eli5why_is_the_crown_victoria_so_popular_within/
|
{
"a_id": [
"co6c1aj",
"co6c208",
"co6dbna",
"co6dg14",
"co6do69",
"co6ep7w",
"co6lgan"
],
"score": [
3,
3,
2,
4,
2,
3,
2
],
"text": [
"was, the Crown Vic is no longer made. Full size sedan, V8 engine, rear wheel drive, made it popular with the police and taxi companies.",
"They use chargers as well (at least where i live)\n\ncrown vics are actually pretty fast once they recieve police package upgrades (tranny cooling etc.)",
"The honest answer? It matched the specifications the police wanted and Ford won the contract to provide these cars for the government. If Chevy had won the bid you would be asking the same question about Impalas. ",
"The Crown Vic was a body on frame design. Where now most cars are a unibody design meaning the body is apart of the frame the Crown Vic's body is build separately from the frame. This allow police to do things like pit maneuvers reducing the risk of significant damage like bending the frame. It also allows for some damage to be done in there own shop for cheap compared to unibody would need a specialist. For example a fender is something that would like be damaged doing a pit maneuver. With a Crown Vic they are bolt on. It's the same reason why a lot of cab companies use them as well. \n\nThere are some significant disadvantaged like lack of crumple zones. This raises the risk of serious injury or death in a serious accident. ",
"Crown Vics and Chevy Caprice were pretty much made for fleet vehicle usage. American made, full size sedan, v8 engine, low redesign cycle, came pre-configured for police usage. With lots of other police departments standardizing on the same vehicle, companies make all kinds of police accessories designed for it. And most importantly inexpensive to purchase.\n\nIncidently, the crown vic after the fuel tank issue, has been discontinued, and designed as the \"police interceptor.\"\n\n_URL_2_\n\n_URL_0_\n\n_URL_1_\n\n",
"Ideal police vehicles, large and powerful. The interior could accommodate a cage separating the front and rear and allow for an acceptable amount of legroom. Wide and bold lines projected power and authority while the large engine could tolerate the endless demands placed on it. Great vehicle ",
"Thank you all for bothering to reply - my curiosity is satisfied and i hope one day to own one of these beautiful cars :)"
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[
"http://www.gmfleet.com/specialty-vehicles/police.html",
"https://www.fleet.chrysler.com/lawenforcement/Pages/index.html",
"http://www.ford.com/fordpoliceinterceptor/"
],
[],
[]
] |
|
25w5ja
|
How does usb data transfer work/ what each wire inside a usb cable for?
|
Hello, i have a few questions. First what does each wire in a usb cable do? I have used one to power and a small electronic device before but i just used the red and black wires(positive and negative). What do the other two do, specificly what is each ones job? Also, when i cut open the cable there was a bare wire. Why is it there if the black wire is the ground wire? Also how do i learn to interact with usb(sending signals through what i assume are the two data cables) with like terminal. What sort of programming language can i write in that i could make a program i can run from the command line and have the data be the parameter of the command? These are my main questions. I'm not quite sure if this is the right place to ask. I don't post much. What i'm wanting to accomplish by knowing all of this is to get a prepaid phone and then replace the keypad with usb input so i can dial and control it from the command line. Also, as a side note i don't use windows, so if you gear you answer towards linux that would be best or osx even. Thanks for anyone who took the time to read this and thanks in advance for the answers.
|
askscience
|
http://www.reddit.com/r/askscience/comments/25w5ja/how_does_usb_data_transfer_work_what_each_wire/
|
{
"a_id": [
"chlxdrs"
],
"score": [
3
],
"text": [
"The other two connections are [Data+ and Data-](_URL_0_). It's a differential signal.\n\nNobody is going to be able to answer all of that in a blog post. You are going to need to do a lot of research or take some classes in college."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/USB"
]
] |
|
ap9y3k
|
how does adding spin to a bullet using rifling make the gun more accurate?
|
[deleted]
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/ap9y3k/eli5_how_does_adding_spin_to_a_bullet_using/
|
{
"a_id": [
"eg6s3k7",
"eg6sheu"
],
"score": [
12,
7
],
"text": [
"It is conservation of momentum, in this case rotational momentum. One of the major problems with early ammunition was that it tended to tumble unpredictably and this would interact with the drag of the air to move them off target. A rotating bullet though tends to want to keep rotating which means that changing where it is pointing is difficult; think trying to turn a gyroscope. Thus rotation keeps the bullet pointing in the direction of the barrel which stops tumbling, increasing accuracy.",
"Objects that spin [maintain their orientation](_URL_0_). This happens because of the laws of conservation of angular momentum; an object that spins will want to continue to spin and not change its orientation or wobble to disturb that spin.\n\nSo the effect is that a bullet that spins will fly through the air point first, and the air will slide around it very nicely and not slow it down much. A bullet without spin will tumble through the air, head over tail, and the air will slow it down and cause it to go off-target unpredictably."
]
}
|
[] |
[] |
[
[],
[
"https://en.wikipedia.org/wiki/Gyroscope"
]
] |
|
3j7wsp
|
why do central banks use interest rates as the primary tool for adjusting the supply of money?
|
You could distribute new money in a number of ways. You could create money and just put it directly in people's bank accounts, you could fund government programs with the newly created money, or you could just drop cash from a helicopter. Why does pretty much every central bank use interest rates, then?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3j7wsp/eli5_why_do_central_banks_use_interest_rates_as/
|
{
"a_id": [
"cun0l4c"
],
"score": [
2
],
"text": [
"Because interest rates also let you adjust the supply of money 'down' too.\n \nCentral banks do have other ways to add money to the economy beyond interest rates. One of the most common is to buy/sell bonds. If the central bank buys bonds then they basically inject money into the banks, and the reduction in supply also will increase the price of the bonds that the banks still hold. This was how the whole \"quantitative easing\" thing that the US was doing worked."
]
}
|
[] |
[] |
[
[]
] |
|
2zxtxo
|
why isn't chicken meat marbled?
|
Beef is always red and varying degrees of marbled. Chicken is either white or dark and not marbled. Why?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2zxtxo/eli5_why_isnt_chicken_meat_marbled/
|
{
"a_id": [
"cpn9iwz"
],
"score": [
3
],
"text": [
"Actually if you have a corn fed chicken that us free range is has a small degree of marbling however because the fat is translucent and thin it nearly always acts like a baste for the bird (which is why many chickens when roasted tend to leech do much fat)"
]
}
|
[] |
[] |
[
[]
] |
|
7fc0hi
|
why can't digital clocks retain the time when unplugged/powered down if phones and computers can?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7fc0hi/eli5_why_cant_digital_clocks_retain_the_time_when/
|
{
"a_id": [
"dqatp84",
"dqatqxm"
],
"score": [
2,
2
],
"text": [
"Digital clocks tend not to have backup batteries, though some do and can keep time across power outages. If more models with this feature were sold then perhaps manufacturers would make it more common. They don't so apparently it's not worth it for people to pay the extra cost.\n\nIf you look at computer motherboards you'll find a small battery that can powers the internal clock and some other functions for 5+ years. This is possible because the clock circuit is designed in the same low-power way as digital watches. Mains-powered clocks mostly use a different principle, based on syncing to the 50/60Hz mains power frequency, and it's not so easy to add a low-power battery backup.",
"Computers have a small battery on the motherboard that typically lasts years and years. \n\nPhones use their internal batteries and additionally rely on the time provided by cell towers (which are connected to computers with little batteries on their motherboards).\n\nYour bedside clock might have a backup battery (mine does), but most of them have no ability to hold onto data when the power goes out."
]
}
|
[] |
[] |
[
[],
[]
] |
||
3oba50
|
why are we so scared to introduce life on other planets?
|
I recently read on a reddit thread that if we were to send rovers to planets that are habitable, we'd have to make sure there are no bacteria and such on it so we don't introduce life on that planet.
Why does it matter?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3oba50/eli5_why_are_we_so_scared_to_introduce_life_on/
|
{
"a_id": [
"cvvnnky",
"cvvnoor"
],
"score": [
9,
5
],
"text": [
"We're not SCARED to, we're trying to avoid wrecking science.\n\nBy bringing in foreign contaminants, you're essentially wrecking any sort of science experience concerning native life. You'll never be able to tell if some discovered earth-like microbe is truly native, or just somehow survived the trip from Earth. \n\nSo unless there's tremendous care to avoid contamination you'd never be able to absolutely verify whether there was life on Mars or elsewhere like in the oceans of Europa. Someone could always argue that it was just brought along from Earth.",
"Because we want to see if there is life on other planets. If we carelessly send our rovers over contaminated with earth bacteria, we are jeopardising that research. Because then, when we find something, we are never 100% sure if it is actually something from Mars or something from Earth.\n\nAdditionally, our bacteria could become an invasive species on Mars. If there is an ecosystem of life on Mars, our bacteria might very well destroy it before we've had time to properly study it. "
]
}
|
[] |
[] |
[
[],
[]
] |
|
7zttct
|
who decided that the standards were 4:3 16:9 21:9 for aspect ratio?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7zttct/eli5who_decided_that_the_standards_were_43_169/
|
{
"a_id": [
"duqpudo"
],
"score": [
3
],
"text": [
"It's because 4:3 is closest to our vision and is best to relay information, 21:9 was already the standard of cinema and is best to describe scenery. 16:9 is just the compromise between those two. \nAnd for where those numbers came from, there's only 1 word: compromise. The artist, engineers, and the market all fought with eachother with their own aspect ratios. Those that survive are the ones we use today. \nExample: there now exist mobile phones with 17:9 and 18:9 resolutions, due to how applications are layed out on the screen (vertical scrolling). Only time can tell if they survive and become the new standards."
]
}
|
[] |
[] |
[
[]
] |
||
3en6hs
|
why does air conditioner cooling use electricity? isn't there an efficient way to absorb thermal energy to produce electrical energy?
|
Can't we convert the heat from our room to power something like a flashlight, and thereby cool the room and produce electricity?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3en6hs/eli5_why_does_air_conditioner_cooling_use/
|
{
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"ctgis74",
"ctgisth",
"ctgiuyb"
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2
],
"text": [
"If you search for \"air conditioner\" on here you'll get some great explanations for how they work. I'd like, however, to address your second question.\n\n > Isn't there an efficient way to absorb thermal energy to produce electrical energy?\n\nThe only way to create usable energy out of thermal energy is when you have a temperature *differential*. It doesn't matter if the air is 100 degrees if you don't have a place to transfer that thermal energy to. You have to have a place that you can dump the energy in order to harvest usable work out of the difference. This dump is often called a cold sink.\n\nSo, if you had hot air inside of a building and cold air outside you could create electricity by moving the heat from inside to the outside. But, at the end you'd eventually have the air inside and outside reach the same temperature and you can no longer create any work from the differential.",
"It might help if you think not of temperature as a value, but of temperature *differences*. In many ways heat is like a fluid -- it aims for equilibrium. In the case of a liquid it will flow from a high place to a lower one, and once there spread out evenly. In the case of heat it \"flows\" from a hot place to a cooler one, and once everything in a system is the same temperature then the flow stops.\n\nThis is the case with air conditioning. You have a hot room inside, and a hot exterior outside. There is no imbalance of temperatures, therefore no change will take place. The only way to overcome this situation is by forcibly changing the situation -- in the case of air conditioning this is done be causing gases to repeatedly expand and contract. And to move those gases around -- or to change the temperature equilibrium using any other method -- requires an input of energy, e.g. electricity.",
"The short answer is no, not really. Not unless you've already got a nice cold heatsink sitting around. \nProducing energy from heat requires a heat gradient. In other words, you need a hot side and a cold side. In a power plant, for example, they've got boilers or a nuclear reactor to generate steam on the hot side, but then they can use cooling towers or water from a lake or river for the cold side, because the steam is so far above the ambient temperature. \nOn the other hand, if it's just plain hot outside, there's nowhere for you to move that heat to create a heat engine. It might be possible to create a small Stirling engine that ran on heat from the air if you had a river or ocean or something to cool the cold end of the engine. But if you don't have cool water or something like that available, you'd be kind of out of luck.\n\nThere is actually an idea for generating power called [OTEC](_URL_0_) which uses the temperature differential between the sun-warmed surface water of the ocean and the deep water hundreds of feet down. And there's also something called earthtubing or passive geothermal which uses the difference between the warm air and the cooler temperature of the earth deep underground to circulate and cool water. Some homes use this very effectively, but it takes a LOT of excavation to install and doesn't actually generate any power; it just uses the fact that, deep underground, the temperature stays more or less the same, whether it's hotter or colder on the surface."
]
}
|
[] |
[] |
[
[],
[],
[
"http://phys.org/news/2009-04-space-based-solar-power-california.html"
]
] |
|
oxj7l
|
Could sign language take root and persist in wild chimpanzees without continued human contact?
|
What is not clear to me is if ASL is just too complex or just misaligned with how they communicate best to be adopted. They (likely) already have a well established means to communicate anything they need to so would it just fade away? _URL_0_
The hypothetical scenario I am thinking of goes something like this: Humans co-locate with the chimps in their native environment, teach them ASL over many years, leave, then the chimps are studied for generations later. Do their offspring learn and in turn teach their offspring? Could this even provide some advantage to them?
Obviously there is no single right answer here but I'd be interested in the discussion.
|
askscience
|
http://www.reddit.com/r/askscience/comments/oxj7l/could_sign_language_take_root_and_persist_in_wild/
|
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"I was interested in this idea, and asked a primatologist who had studied chimp behavior about it. She seemed to think it was relatively unlikely. Apparently chimps very rarely sign at each other, and the chain of behavioral mimicking is kind of one sided and dependent on social status. They also apparently don't tend to learn signs from each other with any great frequency. Low status animals will follow the lead of high status ones, but if a low status animal has a good idea the rest of the troop will often not pick up on it. There's also an interesting anecdote of \"wild\" signing behavior that might be illustrative. The leader in a chimpanzee group will sometimes bang on trees to alert the group to where he is, and help keep them all together, and let everyone know when the group is about to halt or start moving. In one group, the leader worked out a more complex system of signalling based on this, which could indicate length of pauses, direction of movement, and that sort of thing. He used this for years, but after he died the next leader did not pick up the method.\n\nSo yeah, it seems like it would _probably_ fade away. Which is really too bad, as it would make a fascinating experiment if you could give a species proto-language and see how it changed their behavior and ecology.",
"“No chimpanzee has learned sign language. They’ve certainly learned some gestures, but sign language is not just a system of gestures. It’s a full, grammatical language with its own systematic grammar, like Latin.” Psychologist Steven Pinker,\nAuthor of The Language Instinct, Professor of Psychology, Harvard\n\nAlso: _URL_0_\n\nFrom the Language Instinct where he discredits chimp signing.\n",
"Not in the case of chimpanzees, but there are documented cases of parrots that have returned to the wild spreading human words as calls. [Source](_URL_0_). ",
"Koko the Gorilla taught sign language to her adopted son I believe (although this may have been with the help of people)",
"Youtube: Kanzi \n...and Koko: A Talking Gorilla. \nChimps are really good imitators, some chimps have learned signing through sheer observation and not direct instruction.\nI don't think many primatologists agree on this topic, and rightly so. Testing the hypothesis would require a longitudinal study spanning beyond the life expectancy of its researchers. It would be very hard to do. \n\nArticles that I find fascinating and somewhat relevant if you're interested in going on a research hunt:\n\nCarpenter, M., M. Tomasello, and S. Savagerumbaugh. \"Joint Attention and Imitative Learning in Children, Chimpanzees, and Enculturated Chimpanzees.\" Social Development 4.3 (1995): 217-37\n\nTamariz, Monica. \"Could Arbitrary Imitation and Pattern Completion have Bootstrapped Human Linguistic Communication?\" Interaction Studies 12.1 (2011): 36-62\n\nTomasello, M., S. Savagerumbaugh, and AC Kruger. \"Imitative Learning of Actions on Objects by Children, Chimpanzees, and Enculturated Chimpanzees.\" Child development 64.6 (1993): 1688-705\n",
"[This might help](_URL_0_) (Ignore the last part)"
]
}
|
[] |
[
"http://en.wikipedia.org/wiki/Chimpanzee#Communication"
] |
[
[],
[
"http://books.google.com/books?id=l7dryHvwDiMC&pg=PA347&lpg=PA347&dq=steven+pinker+chimp+sign+language&source=bl&ots=VXmbLmYa2P&sig=uMG_ZNxCyjZ0E6YlM-1c5HMEoHI&hl=en&sa=X&ei=I6ohT7eaMuWfiQLY88XmBw&ved=0CDwQ6AEwBA#v=onepage&q&f=false"
],
[
"http://www.australiangeographic.com.au/journal/Parrots-and-other-wild-birds-able-to-talk.htm"
],
[],
[],
[
"http://www.youtube.com/watch?v=0344qRfAOtA"
]
] |
|
7nruk8
|
does darkness have a speed?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7nruk8/eli5_does_darkness_have_a_speed/
|
{
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"text": [
"Darkness is the absence of light. Since a lack of something isn't, in and of itself, a thing it has no bounds on how fast it may move.\n\nIn some setups darkness moves at the speed of light. For example, if you consider a spotlight shining out into space and briefly flash it then you shoot a cylinder of light. The front of the cylinder approaches at the speed of light, then the rear approaches at the speed of light. Arguably the end of this cylinder is darkness, so we could say that darkness was, in this case, moving at the speed of light.\n\nWhile that's the simplest setup it's not the only one. We could imagine a long corridor with a bunch of spotlights pointed down. At some point we could have these spotlights start turning off, one after another, going down the row. This causes a wave of darkness to move down the corridor at whatever speed we want. We could turn off lights 1 meter further down the corridor each second and the speed of dark would be 1 m/s, or we could turn them off 600,000 km further per second giving our darkness wave a speed of about twice the speed of light (note that for this setup we'd need to set things up with timers to allow for the speed of light signal delay, but that's an engineering problem, not a physics one).\n\nSince darkness is just the absence of light it's just as meaningful to look at the wave of darkness moving down the hallway as it is to look at the wave of darkness in our first scenario. In both cases we follow a wave where on one side there's visible light and on the other there's not. It wouldn't be proper to use the corridor experiment to argue that the speed of light is whatever you want because light is a thing in and of itself. You can meaningfully track the motion of an individual photon while no such concept can exist for the lack of photons. \n\nThis notion is similar to a shocking observation some astronomers made at one point. They saw what appeared to be something moving at many times the speed of light which cast doubt on various models until they realized that it was the interference between two large debris clouds. While the debris was not traveling faster than the speed of light the boundary of intersection between the two fields was. A boundary isn't a physical thing so it's not bound by the speed of light. ",
"I suppose it depends on just how you look at things. The speed at which electromagnetic radiation is no longer touching something is the same speed at which it came into contact with that thing in the first place.\n\nBut since some things remain illuminated for variable amounts of time after coming into contact with a light source, and nothing stays dark for a time after coming into contact with a light source, you could say that dark is slightly slower than light. \n\nOutside of that rather flimsy example though, the absence of light does not have speed."
]
}
|
[] |
[] |
[
[],
[]
] |
||
26zyx3
|
Does the photoelectric effect decay?
|
As in, will the affected material produce less voltage over time?
|
askscience
|
http://www.reddit.com/r/askscience/comments/26zyx3/does_the_photoelectric_effect_decay/
|
{
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"text": [
"So it has been a while since I actually did this experiment, but nonetheless maybe I can shed some... light on the matter.. (haha). Ok, so in the photoelectric experiment we have a piece of metal attached to a source, and on the other side is another plate of metal. The point here, is that the whole system is powered by a source (battery or mains), and this is required since we need a potential difference to accelerate the ejected electron across the gap to register a current. \n\nSo you are right in saying that an electron is lost, but you must also realise that an electron is provided by the battery/source. So in this case the whole thing would balance out. \n\nBUT maybe you could devise an experiment in which you had a metal in a vacuum that was just floating in mid air (so zero gravity) and it somehow stayed there in which somehow the electron, once ejected from the metal, was attracted to something even more positive than it. Over time you would have a metal that could not eject any more electrons at that frequency. I'm not sure if anyone has ever done this experiment. I am a physics noob and this is reddit so grain of salt. "
]
}
|
[] |
[] |
[
[]
] |
|
3hondg
|
I heard someone say recently that Rome destroyed themselves because of moral decay and fiscal irresponsibility. This didn't sound right to me, and I wanted to hear what /r/AskHistorians had to say about it.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/3hondg/i_heard_someone_say_recently_that_rome_destroyed/
|
{
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"That was Gibbon, or a fan of Gibbon?\n\nWe'll have to start by defining \"the fall of Rome.\" 410 CE, when it was sacked? 476, when the last Roman emperor abdicated? 1453, with the fall of Constantinople? I know people that argue Rome never fell. Obviously there are as many different theories about the fall of Rome as there are possibilities of dating the fall.\n\nUntil I hear back, let's stick with 476, as that is the traditional date.\n\nProbably the most influential work is Peter Brown, The World of Late Antiquity. Here is a [review](_URL_2_) by Tom Holland (I'm not a fan, but it's not behind a paywall). The argument basically runs such that Rome never \"fell\" but transitioned into something closer to a medieval state, with all kinds of innovations suitable for (their) modern time and basically trucked along. Part of this was incorporating bits of Germanic culture and absorbing an ethnically German but propagandistically (?) Roman, at least in a code-switching sort of way. I couldn't find the Theoderic coin I wanted to demonstrate this, but I found a description [here](_URL_1_):\n > The Roman National Museum holds the only existing contemporary medallion depicting a portrait of Theodoric – a triple solidus whose inscription reads REX THEODERICVS PIVS PRINC(eps) I(nvictus) S(emper).\n\nSo Theoderic is mixing Imperial titles (pius princeps) with what are now Germanic titles (rex). I couldn't find an image, but if I remember correctly, he's wearing Germanic clothes. The article that gave me the legend says he's wearing a mustache.\n\nThe two recent collapse theories I know are Heather and Ward-Perkins. [Here is the BMCR](_URL_0_) review that treats both books. \n\nHeather argues that for a while Rome had managed Germanic migrations fine, and so something changed to suddenly make them unmanageable. That was Attila. The Huns increased pressure on Germanic tribes to migrate to the point that they destroyed Rome's tax base and Rome's ability to cope.\n\nWard-Perkins has a similar theory, except it wasn't the Huns but the Vandals. Ward-Perkins focuses a lot on trade circulation, what kinds of things were being made where, when did long distance trade stop. I think its on his first page that he writes \"stuff happened, bad stuff, lots of it.\" He also relies on the tax base, but in a little more thoughtful way than I remember Heather doing. My copies are boxed up unfortunately.\n\nWard-Perkins thinks the Roman Mediterranean economy operated fine through the Germanic invasions for the most part. Amphorae still get shipped, high-quality pots are still mass-produced, until the Vandals got North Africa in 429. That matters because Germans didn't have boats, couldn't attack Rome's last secure agricultural province. Once the Vandals had got a fleet, Roman economic activity plummeted. The quality of material items goes away. Life gets very bad.\n\nThere are tons of other theories, but I don't think anyone takes Christianity and moral decadence seriously anymore.\n\nThere is one more I'll give you. Huntington, \"Climatic Change and Agricultural Exhaustion as Elements in the Fall of Rome\" *The Quarterly Journal of Economics*, Vol. 31, No. 2 (Feb., 1917), pp. 173-208. Unfortunately you might need JStor access to get it.\n\nThis is the most AMAZING article I have ever read! I loved. I presented it in a graduate seminar and I think I laughed all the way through the presentation.\n\nThe general thesis is that Rome fell because of climate change. That's a remarkably modern position for someone writing in 1917, right? That's something you might hear at a conference today. So far I'm impressed.\n\nAND he has science! He has evidence from dendrochronology that average temperatures in Italy increased both during the period of the end of the Republic, and again, after a cold spell, around the collapse of the Empire. He has a typology of theories of climate change:\n > Four chief climatic hypotheses have held the field.\nTheir key words are (1) uniformity, (2) local changes,\n(3) progressive world-wide change in one direction,\nand (4) pulsatory oi irregular changes sometimes in one\ndirection and sometimes another.\n\nHe says he needs only a change of 2 degrees F to cause climactic change to bring down governments. Alright, sounds reasonable. I'm on board. Tell me about this dendrochronology.\n\nWhat's that? It's not from Italy? It's from THE CALIFORNIA REDWOOD? Alright, you're supposing the climate of California and Italy were similar in the first millennia CE. Fine, they're roughly on the same parallel. But don't you think there's a difference between being confined in a bounded, fairly small sea, and being on the coast of the Pacific? Oh, there's an answer for that.\n\nI think I'm going to have to plug in a big quote here.\n > It has long been known\nthat many of the leaders both in ancient Rome and\nGreece belonged to the fair Nordic race. [EDIT - I overlooked highlighting this passage] **Why else do\nso many of the ancient painted statutes of the gods and\ngoddesses of Greece have red or yellow hair and blue\neyes? Not all the leaders, to be sure, were tall, fair\nNordics; for Socrates, the greatest mind of all, was short\nand dark - a typical member of the Mediterranean\nrace. Yet the fair people from the north were sufficiently\naggressive and dominant to cause the favorite\ndivinities, Zeus, Apollo, Pallas, Diana, and others to\nbe represented as of that race.** [He means Greek gods are Nordic] The climate of both\nGreece and Italy, however, is thought by many authorities\nto be too sunny for the blond Nordics. It often\ninduces diseases of the skin and nerves, and in the long\nrun apparently lessens the rate of reproduction. Thus\nin a climate like that of Italy, especially southern Italy,\nthe agressive Nordic part of the population tends to\ndiminish. This tendency would be less, however, under\nthe conditions which we suppose to have prevailed\nthree or four hundred years before Christ, and on the\nother hand, would increase with the changes of climate\nhere described. When combined with the Roman prac-\ntice of beinging in slaves from conquered countries, it\nmay have helped to bring about a gradual change in\nracial type. The race which apparently provided the\nmajority of Rome's early leaders appears to have\ndeclined in numbers, and the decline was presumably\nhastened....\n\n > On the basis of the actual achievements of thousands\nof people under different conditions of climate, it is\npossible to make a map showing the amount of energy\nwhich different races would have in different parts of\nthe world on the basis of climate alone.' This map is\nstrikingly like a map of civilization. **The resemblance\nof the two indicates that today the active and progressive\nraces, those that dominate the world, are all\nlocated in climates which possess a highly stimulating\nquality.** If we are right in thinking that the response\nto climate is almost the same among all races, the\nmatter is highly significant in our interpretation of the\nfall of Rome. As we have already seen, the climatic\nchanges which have apparently taken place in Italy\nappear to have been characterized by a decline in the\nvariability of the weather from day to day, especially\nin the spring and summer. This means that three or\nfour centuries B.C., Rome was blessed with a climate\nwhose mean temperature was as good as that of today,\nand which at the same time was better than that of the\npresent, not only for agriculture, but in its stimulating\neffect on human activity. It apparently possessed\nthe sparkle and tang which our own climate in the\nnorthern United States possesses to so marked a degree.\n\n > If this is so, the change which took place between 300\nand 200 B.C. and still more the gradual change between\nthe time of Christ and the seventh century probably\nhad an appreciable effect upon the energy and ability\nof the Roman people.\n\nSo, Rome collapsed because of the two conditions of a slave state and higher average temperatures drove out Rome's original Nordic population, or reduced them to the intellectual moral equivalents of Cubans and other marginalized groups? (\"Strange as it may seem, the\nnegro or Cuban in the southern part of the United\nStates shows scarcely more adaptation to a hot\nclimate than does the white man, while the Finn and\nSwede of the far north are weakened by low temperature\nalmost as much as is the negro.\")? And that the climate of the northern USA is in the sweet spot that made Rome's Nordic population so effective? Ahahahahaha!\n\nThis is the most fantastic thing I've ever read!",
"Moral decay as a cause for the 'fall' of Rome seems doubtful, because I see no evidence that people in the late Roman empire were any worse than their forefathers. If anything, the surviving law-codes and theological treatises would suggest that as the empire became a Christian one people became more and more concerned about morals, since we start to have records of people doing some pretty extreme things in order to demonstrate their piety, such as living on pillars (Symeon the Stylite), giving away all their wealth (St Melania the Younger), and arguing that even marriage was inferior to chastity (St Jerome). These people were exceptional individuals, but they tell us a bit about the models other Christians might aspire to in the fourth and fifth centuries. \n\nAs for fiscal irresponsibility... again, I am not convinced. The ancient economy was a very complex one and we cannot overlook the role played by other political and social factors. Can you point me to a source that says this? The Western Roman Empire in the fifth century had very little money, but that was because it lost its tax-base in Africa and had to maintain a disproportionately large army to defend itself. Not really fiscal irresponsibility in my opinion.\n\nI'm definitely one of those people who argues that 476 wasn't particularly important and you can read my perspective on the empire's decline [here](_URL_0_), which synthesised various historians' views. Aside from Heather and Ward-Perkins, I also drew upon Guy Halsall's argument that it was internal conflict that led to the western empire's decline in power. For a long-term cultural perspective, check out my answer [here](_URL_1_), which argued that very little changed in the post-Roman world and so the 'fall' of Rome didn't matter all that much. Above all, we have to keep in mind that the Eastern Roman Empire survived the fifth century and would remain an important player in European history until its very end in 1453. If the Romans in the fifth century were so decadent and unable to manage their money, how did the Romans in Constantinople manage to weather the crisis? ",
"Rome's problem was that the economy was wrecked and transformed by the crises in the third century AD, and then the empire suddenly found itself as the end point of one of the largest sustained population migrations in history. \n\nIn earlier times, Rome was able to assimilate populations (or at least the elites of those populations) fast enough to maintain the empire. But when the Huns pushed everyone west into an already reeling empire, the Romans simply couldn't absorb them and cope fast enough before the Huns arrived.\n\nOnce the Huns arrived, the Romans essentially lost all leverage over the tribes that had migrated into the empire."
]
}
|
[] |
[] |
[
[
"http://bmcr.brynmawr.edu/2005/2005-07-69.html",
"http://www.coinsweekly.com/en/Archive/8?&id=222&type=a",
"http://www.historytoday.com/reviews/classic-book-world-late-antiquity"
],
[
"https://www.reddit.com/r/AskHistorians/comments/3dquzd/why_did_the_romans_fall_regardless_of_their/",
"https://www.reddit.com/r/AskHistorians/comments/3gn6q4/are_there_any_post_western_roman_empire_roman/"
],
[]
] |
||
9cgyge
|
Did Heisenberg purposely handicap the development of the Atomic Bomb for Nazi Germany?
|
I’ve heard a rumor that he did so I’m hoping for a confirmation. :)
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/9cgyge/did_heisenberg_purposely_handicap_the_development/
|
{
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],
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"text": [
"There is no real evidence of this, and Heisenberg himself never really claimed this. [See this previous thread for a thorough discussion](_URL_0_). Please feel free to ask any follow-up questions."
]
}
|
[] |
[] |
[
[
"https://www.reddit.com/r/AskHistorians/comments/1wa3kc/is_there_any_truth_to_the_story_of_heisenberg/"
]
] |
|
7dzxcs
|
if any distance can be halved, at what point do you stop touching something?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/7dzxcs/eli5_if_any_distance_can_be_halved_at_what_point/
|
{
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"text": [
"Uh... if you're taking your finger off something, then the distance will increase, halving is a decrease.\n\nAlso, from a physics standpoint you never actually touch anything...\n\nAside from those, you're describing a form of one of Zeno's Paradox. Ultimately the solution is the fact that in the limit, 0.99999.... is equal to 1.",
"You're never touching anything - you are just as close as possible to it. The sensation you feel is effectively the force of the atoms \"pushing back\" against your fingers (and your fingers' atoms \"pushing back\" against the atoms in whatever you are touching). Think of it a bit like how two magnets push against each other, but much much stronger.",
"Planck length, the smallest possible measurement in the universe before the laws of physics break down."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
||
foemj
|
Theoretical Question about subatomic particles. The thought came to me when pondering solar system formation...
|
We know matter is made up of atoms which are revolving around one another's subatomic forces. Just like gravity is draws together dust in the vacuum of space. Some particles obey gravity and some do not. So we're thinking there's an even smaller particle which for some reason defines gravity. Wouldn't it be safe to assume there could be even smaller particles influenceing or constructing the basis quarks and all of those super-tiny particles?
Or maybe the simple rotation of a super-tiny particles or even atoms could define if the particle has mass or not. In the same way a gyroscopic motion effects the weight of an object but not the mass. If we knew a type of radiation or some other method to affect something so small maybe we could test for this
So what am I missing which would disprove this? tell me askscience!
|
askscience
|
http://www.reddit.com/r/askscience/comments/foemj/theoretical_question_about_subatomic_particles/
|
{
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"text": [
"This might be a lost cause, but here goes...\n\n\n > We know matter is made up of atoms which are revolving around one another's subatomic forces. \n\n\nSubatomic particles like electrons \"orbit\" protons and neutrons in some sense...\n\n\n > Just like gravity is draws together dust in the vacuum of space. Some particles obey gravity and some do not. \n\n\nAll particles obey gravity.\n\n\n > So we're thinking there's an even smaller particle which for some reason defines gravity. \n\n\nWhat? Defines or defies?\n\n\n > Wouldn't it be safe to assume there could be even smaller particles influenceing or constructing the basis quarks and all of those super-tiny particles?\n\n\nNo, but it's not impossible that there are more than 4 forces at really high energies.\n\n\n > Or maybe the simple rotation of a super-tiny particles or even atoms could define if the particle has mass or not. \n\n\nIn some sense you're right...binding energy is mass. Up quarks are ~3MeV, down quarks are ~5MeV, but proton = 2 up + 1 down = 940MeV.\n\n\n > In the same way a gyroscopic motion effects the weight of an object but not the mass. \n\n\nI don't think this is true, but I might have missed something in mechanics (highly unlikely, as I teach it every other year or so).\n\n\n > If we knew a type of radiation or some other method to affect something so small maybe we could test for this\n\n\nI suppose... if we go so small (or equivalently very high in energy). However, what you're talking about is probably not achievable.\n\n\n > So what am I missing which would disprove this? tell me askscience!\n\n\nI *think* you're talking about a fifth force acting on a really small scale. In that case, it's just not testable and probably never will be.",
" > Some particles obey gravity and some do not\n\nNot true.\n\nAnyway, there's no evidence to suggest that quarks and other particles have internal structure or sub-particles. There was evidence to suggest the same of protons and neutrons before quarks were discovered. Some people call the hypothetical particles you're talking about \"preons.\""
]
}
|
[] |
[] |
[
[],
[]
] |
|
14e0bn
|
Based on probability and how the universe is ever expanding...
|
askscience
|
http://www.reddit.com/r/askscience/comments/14e0bn/based_on_probability_and_how_the_universe_is_ever/
|
{
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"c7c7mmk"
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2
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"text": [
"The universe is expanding but not infinite. There isn't more universe it just gets larger, space expands. The quantity of mass and energy is finite."
]
}
|
[] |
[] |
[
[]
] |
||
5c7m3m
|
how do contactless cards work?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5c7m3m/eli5_how_do_contactless_cards_work/
|
{
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"text": [
"They use radio waves. The cashier's terminal powers the card and the card emits a signal containing info connecting it to your account and the necessary security details to make sure it's genuine. It's basically a wireless version of chip cards. The time it takes to complete the purchase depends on hardware of the terminal, how bloated the software on the terminal is (bunch of graphics on the screen and whatnot), and the Internet connection (speed and ping) of the business. \n \nContactless cards use RFID, which receive power to work; NFC payments like Apple Pay supply their own power. This is why you don't have to charge your card."
]
}
|
[] |
[] |
[
[]
] |
||
1ockdm
|
why is it considered healthy to put oil on your salad, but not fry your food in it?
|
You always hear people say that oil and vinegar on a salad is a healthy choice, yet if I fry anything in the same oil it isn't considered healthy?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1ockdm/eli5why_is_it_considered_healthy_to_put_oil_on/
|
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"text": [
"Putting fats on salads is good because it helps absorb the fat soluble vitamins in salad. Frying on the other hand isn't good because first off heating up fats to the point of frying isn't good for the fats and second off cooking food too much destroys food and produces carcinogens. ",
"Oil consists of different kinds of fat. Saturated, monounsaturated and polyunsaturated fats. You can think of them as a chain. Saturated fats are strong, whole chains, while monounsaturated fat have a weak link (mono = one). Polyunsaturated fats have more weak links. When you heat up the oil (or leave them for too long on your shelf) those weak links gets damaged by heat and oxidation, like rust on a chain. This damage causes the fat to become really unhealthy and can cause problems like cancer, atherosclerosis and all kind of other nasty stuff. [More info](_URL_1_). \n\n\nYou should always pick a cold pressed (not heat damaged) virgin (non-chemically treated) oil. [Many oils are treated with chemicals, heated and bleached](_URL_0_) (seriously!), all very damaging to the oil. A rule of thumb: the thicker the fat, and the less refined, the better. \n\n\nEdit: You could also look up the oils smokepoint as glycerol in oil is converted to acrolein when it starts to smoke and burn. That's one of the things in cigarettes that cause lung cancer. \n\nGood fats: Macadamia and coconut are great. Olive oil if you don't heat it. "
]
}
|
[] |
[] |
[
[],
[
"https://www.youtube.com/watch?v=omjWmLG0EAs&amp;amp;feature=youtube_gdata_player",
"http://onlinelibrary.wiley.com/doi/10.1111/j.1745-4506.2001.tb00028.x/abstract;jsessionid=D04D633146812B9AFE4F9CDB0E0C6B48.f01t02"
]
] |
|
5a0kxn
|
what is going on in south korea right now?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5a0kxn/eli5_what_is_going_on_in_south_korea_right_now/
|
{
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"text": [
"[South Korean explained it well.](_URL_0_) Warning though it's from a chan board so it's highly offensive. It's a great explanation, but still offensive.\n\nEDIT: Made an imgur album for you with more information.\n\n_URL_1_",
"**Pasting this, and modifying this from a comment /u/flyawaystupidkite made. Send him your love.**\n\nIt's a bit insane. So I'll try going step-by-step from memory how this all turned about.\n\n1. A young high school girl fails to get into a prestigious university.\n\n2. The girl's mother (Choi Soon-sil) uses her influence to pay the girl's way into prestigious university. They package it as the girl receiving a scholarship for her equestrian skills.\n\n3. Girl doesn't do so well in school and later turns out she had a child during her high school years which was no-no for this school's policies.\n\n4. Girl decides to take some time off but still demands her grades to be given to her as if she had completed her semester.\n\n5. Professor says no. This incurs the wrath of the girl's mother who successfully convinces the professor to give her the grades. \n\n6. This leads to a massive 80 day protest from students of that university for unfair treatment and etc.\n\n7. This leads into investigation that eventually reveals the girl's mother had a personal relation with President Park.\n\n────────\n\nOh shit it's about to get real funky now.\n\n────────\n\n1) The girl's mother turned out to be one of like 15 known children of a famous cult leader (Choi Tae-min). Each child was known to have extreme assets from estimated 10s of millions to upwards of billions.\n\nEDIT: 1a) \"The elder Choi reportedly enjoyed considerable influence over Ms Park as a young politician, prompting diplomats to refer to him in private as “Korea’s Rasputin.”\nA newly released Wikileaks cable from the US embassy in Seoul described him as having “complete control over the body and soul of the president in her formative years. Both women are understood to have met decades ago and formed a close relationship when Ms Choi’s father allegedly helped the future president contact her late mother in the afterlife.\" Source: _URL_0_\n\n2) President Park had a scandal in the past (that many dismissed as they deemed highly improbable and a likely attack from opposing political parties) that said apparently she had a child with this cult leader while she was in her teens.\n\n────────\n\nSo how does this relate directly to the Korean people?\n\n────────\n\n1. As investigations ensued it turned out that the President Park had been exchanging emails regarding her speeches and other national policies and events with the girl's mother (Choi Soon-sil). Even going as far as asking her for edits and such.\n\n2. Journalists, during the investigation, received a tablet from President Park? Girls mother? That for some reason contained all the exchange between them. This is thought to be an unfortunate mistake by them and a fortunate mistake for the Korean people to know the truth. \n\n3. The investigative journalists are doing this via wikileak style and slowly releasing information. More and more information have been coming out each day.\n\n4. Latest news is what you've guys read. It seems the relationship between President Park and the cult leader's daughter (girl's mother) have been more intimate and influential than people thought. Even going so far as President Park, after a hard day, going to their residence to sleep over and discuss the problems and getting advice and what not. All national secrets out on the table for the cult family. \n\nEDIT: Choi, who is currently in Germany, says she is too ill to return to Seoul for questioning over the affair.\n\n“I am suffering from a nervous breakdown and I have been diagnosed with heart issues,” she toldSegye Ilbo, a South Korean newspaper.\n\n\n────────\n\nIt's still a developing story. Koreans are wondering why the President haven't stepped down yet. It's either that or impeachment and jail for her. \n\nIt's a sad day when people are saying Korea's best presidents so far were either the dictators or the ones who just didn't do any crazy shit while in office. \n\nAll this because of one spoiled ass girl dealing with a broken education system in Korea. \n\nP. S. Be careful criticizing that spoiled ass girl. She's been threatening to kill everyone criticizing her over the internet :)\n\n",
"I used to be someone who tell people that thinking a secret cult is behind the government is bullshit... now this shit will be the holy grail for those mother fuckers to keep saying that all governments are like this.",
"Obviously this is all batshit insane, but one of the worst parts is that Universities won't let you attend if you've had a child?! I thought Korea was better than that. "
]
}
|
[] |
[] |
[
[
"http://imgur.com/UvJ8P3l",
"http://imgur.com/a/lsttr"
],
[
"https://www.google.ca/amp/www.telegraph.co.uk/news/2016/10/29/secret-advisers-nepotism-and-even-rumours-of-a-murky-religious-s/amp/"
],
[],
[]
] |
||
q7ydc
|
Do women with big breasts have bigger risk of breast cancer than women with small ones?
|
My thought is that since there is more tissue,there might be a bigger chance that one cell could develop _URL_0_ this correct or does the number of cells have nothing to do with the probability of cancer development?
|
askscience
|
http://www.reddit.com/r/askscience/comments/q7ydc/do_women_with_big_breasts_have_bigger_risk_of/
|
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"It's an intuitively appealing thought, but at present no studies have shown a definitive link between breast size and breast cancer rates.",
"There is no conclusive evidence for this. There are several risk factors for breast cancer: one is genetic, and quite aggressive . You can get tested for this type of cancer and it very strongly runs in families.\n\nAnother thing that increases the risk for breast cancer is not having kids, or having them late, which is why it was once called \"nun's disease\". Women who started their period very early also have a slightly increased risk. Some oral contraceptives have also been linked to a slightly heightened chance of BC. But no evidence for breast size being a factor.",
"Interesting question.\n\nFirstly, it is important to note that in non-pregnant women, differences in breast size are largely due to different amounts of adipose (fatty) and connective tissues. The size of the actual mammary glands and ductal systems do vary, but not greatly, between non-pregnant woman. It is from these parts of the breast that breast cancers can arise, and not from the fatty tissue. (Side note: cancers can arise from fatty tissues, such as liposarcomas, but these are generally not referred to as breast cancers, even if arising in the fatty tissue of the breast). Only when a woman becomes pregnant do the glands and ductal systems develop and proliferate, causing an increase in breast size.\n\nBearing this in mind, it would seem unlikely that an increase in breast size would cause an increase in cancer incidence. Indeed, the papers I could find on the subject (listed below) suggest there is no link between breast size and cancer rates, aside from a possible anti-carcinogenic effect of silicone implants.\n\nKoch, AD, Nicolaia JPA, de Vriesb J. Breast cancer and the role of breast size as a contributory factor. Breast. 2004 Aug;13(4):272-5.\n\nTavani A, Pregnolato A, La Vecchia C, Negri E, Favero A, Franceschi S. Breast size and breast cancer risk. Eur J Cancer Prev. 1996 Oct;5(5):337-42.",
"At it's base, this question is about more cells meaning more cancer. That does not seem to be the case. It really is a poorly understood phenomenon. We can also extend the question to why aren't elephants and whales riddled with cancer? Here is a blog post by Carl Zimmer that discusses this idea:\n\n_URL_0_",
"Would larger breasts statistically have larger tumors or more massive tumors than those with small breasts?\n\nDoes this data apply to men?",
"One of the reasons that a correlation (not causation) between breast size and cancer is due to obesity. Breast size increases as your BMI increase, likewise so does breast cancer risk (as well as other types of cancer).\n\n_URL_0_",
"Denser breasts are more prone for breast cancer.\n\n_URL_0_",
"According to my extremely credible source (my social evolution college class), bigger breasts do not increase your risk of actually getting cancer, but once breast cancer actually occurs the tumors tend to be larger than those with average sized breasts.",
"Actually, women with \"dense breasts\" are considered higher risk of cancer. Women with dense breasts tend to be athletic with smaller breasts containing more muscle and connective tissues than fat/adipose tissue. There is some argument as to whether dense breasts just make it harder for radiologists initially diagnose the cancers, so when they are found, they tend to be further along and more aggressive; but research seems to confirm something about the higher level of the dense tissues itself makes the cancer more aggressive. _URL_0_",
"malignant tendencies can manifest from any form eukaryote cell. Of course there are many environmental variables (ex. exposure to sunlight, diet ect.) you must consider. However the actual size of the breast would have little to do with determining a persons likely hood of developing breast cancer. The best way to accurately calculate your risk is to examine your heredity. ",
"I would think that with the amount of global research that has gone into breast cancer as well as the massive ongoing publicity campaigns, if there was such a simple yet vital correlation then we would all know about it. It would not be some obscure, little-known fact.",
"Very interesting question. I'd like to raise a more general variation of it: \n\nAre larger animals more likely to develop cancer compared to smaller ones due to being composed of a larger number of cells given similar lifespan and metabolic rate? ",
"Does cancer really operate in this way though? I.e. can a strict probability analysis correlating the amount of potentially cancer-affected substance to that material actually developing cancer actually be applied? It seems like there are far too many variable to make this calculation feasible. ",
"The consensus seems to be no, so I'm now wondering why women are at a higher risk of breast cancer than men, is it due to the higher amounts of estrogen?"
]
}
|
[] |
[
"cancer.Is"
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[
[],
[],
[],
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],
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"http://annonc.oxfordjournals.org/content/15/6/850.full"
],
[
"http://www.breastcancer.org/risk/new_research/20070122b.jsp"
],
[],
[
"http://www.health.harvard.edu/newsletters/Harvard_Womens_Health_Watch/2011/October/the-breast-density-breast-cancer-connection"
],
[],
[],
[],
[],
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] |
|
28bzvx
|
Did the crocodile attacks during the 1945 battle of Ramree Island actually happen?
|
This story seems to pop up in TIL pretty often. The short version is that a large number of Japanese soldiers (between 400 to 1000 depending on the "source") were eaten by saltwater crocodiles during the night of Feb 19th 1945 during the battle of Ramree island as part of the Burma campaign.
The story seems to hinge on the account of a naturalist called Bruce Stanley Wright as the only primary source. I recall a fairly thorough debunking of this tale on AskHistorians but I can't seem to find it.
Was the event corroborated by any other primary sources or likely urban legend?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/28bzvx/did_the_crocodile_attacks_during_the_1945_battle/
|
{
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"ci9g6ia"
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"text": [
"This is what I wrote the last time it was brought up: \n\nThe story never happened. It's complete fiction.\n\nBut Bernardito, wasn't it included in the Guinness Book of World Records? Doesn't Wikipedia confirm as true?\n\nHere we get to the interesting part. \n\nFirst, the truth: February 1945. It's the final stages of William Slim's brilliant Burma campaign and the British have trapped a Japanese force counting around a thousand men in the islands of Ramree. Instead of surrendering, the Japanese commander chose to take his men across an unblocked route through ten miles of mangrove swamps. Many were already in a bad state entering the swamp. Malaria was rampant. As one can imagine, swamps are not pleasant places. They are filled not only with deadly insects and snakes but are truly a nightmare to get through. Out of 900 troops that went into the swamp, 500 made it out. \n\nThe myth: The above story except that by the end 20 troops were captured by the British, the rest were all killed by saltwater crocodiles. This is a 'reported account' from this encounter: *\"That night was the most horrible that any member of the ML crews ever experienced. The scattered rifle shots in the pitch black swamp punctured by the screams of wounded men crushed in the jaws of huge reptiles, and the blurred worrying sound of spinning crocodiles made a cacophony of hell that has rarely been duplicated on earth. At dawn the vultures arrived to clean up what the crocodiles had left... Of about 1,000 Japanese soldiers that entered the swamps of Ramree, only about twenty were left alive.\"*\n\nWhy is this a sensationalist myth?\n\nThe observer of this is according to most accounts a certain [Bruce Wright](_URL_0_) who for some reason was in this swamp where this is said to have taken place, sitting in a motor launch and witnessing this. Yet only Wright's *Wildlife Sketches Near and Far* exists as the single account for this to have happened.\n\nThere is no other single source that can verify this event to have happened and the actual survivors themselves that came out of the swamp is enough to disprove this myth. There is no mention of it in official British records and W.O.G. Potts did his own research into this with an incredibly detail investigation in which he interviewed a broad range of people which included Ramree islanders, survivors and soldiers. No one acknowledged that an incident like this had taken place.\n\nLastly, historian Frank McLynn has this to say in his book *The Burma Campaign*: \n\n*Most of all, there is a single zoological problem. If 'thousands of crocodiles' were involved in the massacre, as in the urban (jungle) myth, how had these ravening monsters survived before and how were they to survive later? The ecosystem of a mangrove swamp, with a exiguous mammal life, simply would not have permitted the existence of so many saurians before the coming of the Japanese (animals are not exempt from the laws of overpopulation and starvation).*\n\nThe Wikipedia writer is overly critical about Frank McLynn in the article, for whatever reason that might be. While McLynn did indeed doubt the existence of Mr. Wright but as pointed out in the *Talk* section of the page in question, there is no evidence that the Wright who wrote the book which had the only account of the incident and the Wright which the Wikipedia page uses as a source (a dubious one at that) is the same person. Secondly, the Wikipedia page makes McLynn seem like someone making claims out of thin air which is ridiculous. He's using scholarly sources to back up his claim and is definitely not the only author doubting this story. (Just see Platt SG, Ko WK, Kalyar Myo M, Khaing LL, Rainwater T. *Man eating by estuarine crocodiles: the Ramree Island massacre revisited.* Herp Bull. 2001;75:15–18)"
]
}
|
[] |
[] |
[
[
"http://books.google.se/books/about/Wildlife_Sketches_Near_and_Far.html?id=Kb9XmQEACAAJ&redir_esc=y"
]
] |
|
4u0d4o
|
If Hexagons are the Most Efficient Way to Store Something in Two Dimensions, What is the Best For Three?
|
askscience
|
https://www.reddit.com/r/askscience/comments/4u0d4o/if_hexagons_are_the_most_efficient_way_to_store/
|
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"text": [
"[This is the current best solution](_URL_0_)",
"If by \"efficient\" you mean packing spheres into a volume (as opposed to the efficient hexagonal tiling of circles on a plane), there are actually two solutions: the face centered cubic (fcc) lattice and the hexagonal close packed (hcp) lattices, which both achieve a packing density of Pi/(3*Sqrt[2]) or about 74%. This was recently proved by TC Hales in 1998. \n\nAn example of the face centered cubic lattice is the stacking of oranges or cannonballs into a pyramidal stack. The fcc and hcp lattices differ by a shift between layers of the lattice, with fcc being a shift of ABCABCABC (the same shift between layers) and hcp alternating between shifts ABABAB. \n\nNot coincidentaly, many metals or other elements also arrange their atoms in the fcc and hcp lattices. For example aluminum, copper and nickel are fcc, and titanium and magnesium are hcp. There are other alternatives. In practice there are many considerations to how atoms pack into crystal lattices, but many elements are fcc and hcp.",
"It depends on how you define efficient: greatest volume per square unit of packaging? Weaire-Phelan. Least amount of unutilized space? Least amount of wasted space in a shipping container or truck? Different answers altogether.\n\nRectangular prisms work really well for most purposes which is why milk cartons and cardboard boxes are common. Weare-Phelan does not work well for packing in shipping containers."
]
}
|
[] |
[] |
[
[
"https://en.wikipedia.org/wiki/Weaire%E2%80%93Phelan_structure"
],
[],
[]
] |
||
3biq6m
|
how can it be cheaper for a company to hire a contractor rather than new employees?
|
Wouldn't the contractors need to be paid basically the same amount as a theoretical new employee? And then wouldn't the contractor somehow need to turn a profit? It seems like contracted work would ultimately be more expensive than doing it yourself.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3biq6m/eli5_how_can_it_be_cheaper_for_a_company_to_hire/
|
{
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"text": [
"In my case, I had a small project that was supposed to run for a few months. I did not want to hire a full time employee, because I had nothing for them to do after this project. Hired a contractor, got the project done. Worked out well since the cost of using a contractor for a few months was within the project budget.",
"Employees have certain costs above and beyond a contractor. Even if you're paying less per hour, the total cost can be far more.\n\nContractors handle their own taxes, no need to pay an accountant or payroll company to do it for you.\n\nContractors are not eligible for company benefits. No 401k fees or contribution matching, no stock options, no insurance premiums, etc. (This is MAJOR).\n\nContractors are usually employed as needed. Just need 4 days of work? No problem, someone will be there in the morning and gone when you're done, just pay for the time they're there. Employees, on the other hand, need to be interviewed, trained, put through orientation, etc. Then, to fire them, there are all the processes involved, ERISA compliance with notifications, COBRA insurance continuation and administration, etc. It's wildly impractical for any sort of short term or \"overflow\" work.\n\nAs an aside, contractors often have their own training and equipment. For example, hiring a printer repair man makes no sense for most offices, and neither does having all the tools and parts to repair. Hiring a contractor to come in and fix machines as needed is a much better solution."
]
}
|
[] |
[] |
[
[],
[]
] |
|
3m41i8
|
why has there been a new 3d printer getting fully funded on kickstarter every month for the past 3 years?
|
Every time I get on Kickstarter, there's always a new 3D printer that's fully funded for several hundred thousand dollars, but doesn't look any different from previous printers. This has been going on for years. What are they doing that is any different from the dozens of other printers already out there?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3m41i8/eli5why_has_there_been_a_new_3d_printer_getting/
|
{
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"cvbtsc2",
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"text": [
"There has yet to be a truly consumer friendly 3D printer on the market, they just need to much maintenance and calibration to remain useful. People keep coming along thinking they can solve this problem, but no one has so far.",
"I said the exact same thing 4 years ago, when I built my first 3d printer. Its because nobody had produced a model that is anywhere near perfect, and they are all ridiculously expensive. What you are seeing on kickstarter is not revolutionary, they are just making small adjustments. For example: The first repraps (such as the purusa, the original ones that were developed in basements) had accuracy to 0.9 mm thick per layer, and it did it very slowly and still looked terrible. The newer ones can go all the way to 0.01 mm thick. So if you were to invent a brand new 3D printer that could print to 0.01 mm per layer, and do it faster than anything out on the market, you could have a potential money maker that people might want to have."
]
}
|
[] |
[] |
[
[],
[]
] |
|
21jr3h
|
why aren't pico projectors a huge thing now, and why aren't they the number one feature in all smartphones?
|
I understand power draw. Clearly they well annihilate a current smartphones battery. I'm saying why isn't this the next smartphone push? If you're phone can be the TV, it can then be the console, the set top box, the sports center.
Why isn't this being focused on more, at least publicly?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/21jr3h/eli5why_arent_pico_projectors_a_huge_thing_now/
|
{
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"cgdp9fq"
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"text": [
"because they suck and everyone still has a laptop or a tablet. So...if you ask me, until they work better AND the phone can replace a laptop/tablet then it's just wasted money. If you're sitting there with your laptop/table and your pico projector phone and you wanna watch something it's not a hard decision. They just aren't \"there\" yet on the scale that can get them into a phone."
]
}
|
[] |
[] |
[
[]
] |
|
5ox5s7
|
why, when slowly opening a plastic soda bottle, does a little air come out when you crack it a little open, but then more comes out when you open more?
|
If the first crack is enough to let some air out, Spyker it be enough to let it all out?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5ox5s7/eli5_why_when_slowly_opening_a_plastic_soda/
|
{
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"text": [
"Most sodas are carbonated, this means that they have carbon dioxide gas (CO2) dissolved in them. There are a variety of things that can cause a solution (the soda) to release a dissolved gas (the CO2), heat and agitation being the two your soda is most likely to encounter.\n\nAdditionally, most sodas are overpressured with CO2 to make sure that they stay carbonated until they get to you. When you first crack open a soda, it's this CO2 that you hear leaving, and if you left it just barely cracked open long enough it certainly would reach equilibrium with the air around the bottle and you wouldn't hear any more gas leaving.\n\nSo the short answer to the question is yes. The very first crack is enough to let all the gas out *if you leave it long enough*. Think about it like this, if you had a 5 gallon bucket of water and you knock a small hole in the bottom, the bucket isn't going to empty immediately it can only empty as fast as the force pushing it and the fluid that it's pushing will allow. Your bucket will eventually empty, but not immediately. Now, if you got impatient with your small hole and decided to knock out the bottom of the bucket, it would empty immediately because now there's nothing holding the liquid back, like if you take the cap completely off of a soda.",
"Your whole high school is in the gym for an assembly. The presentation comes to an end and everyone needs to leave all at once. \n\nIf you never open the doors, people will never leave. \n\nIf you open one door, how long will it take for everyone to leave? \n\nIf you open all the doors, how long will it take for everyone to leave? \n\nRelate this to your problem. Basically, it doesn't matter how fast or slow you open the bottle, the air will equalize anyway. It's only a function of how fast it equalizes. "
]
}
|
[] |
[] |
[
[],
[]
] |
|
g62di
|
If humans had evolved with easy access to food, how would body functions change?
|
What I'm thinking of is how we can't grow back amputated limbs, or that cuts can take quite a while to heal. And I'm sure many helpful abilities humans might have had (maybe enhanced eyesight, for example) were chopped off due to expensive "maintenance work".
But what if we had always had easy access to nutritious, calorie-rich food?
In another way of asking the question, is it possible to engineer an organism that had superpower-like bodily functions at the expense of it needing lots of food?
EDIT: here's another one: could you create an organism that never slept, but instead ate tons of food to compensate?
|
askscience
|
http://www.reddit.com/r/askscience/comments/g62di/if_humans_had_evolved_with_easy_access_to_food/
|
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],
"text": [
"If our ancestors had lived in a world where food was plentiful and easy to get (say, in a forest of cheesecake trees), then they simply would have reproduced and reproduced until they were so numerous that food stopped being plentiful and easy to get. \n\nIn this new world, the main obstacle to you getting food is outcompeting all the other members of your species who are going for the same food, so those who thrived would be vicious and excellent at fighting. ",
" > What I'm thinking of is how we can't grow back amputated limbs, or that cuts can take quite a while to heal. And I'm sure many helpful abilities humans might have had (maybe enhanced eyesight, for example) were chopped off due to expensive \"maintenance work\".\n\nThis assumes that regeneration is omitted only because of lack of enough energy. But it is also extremely likely that we can't regenerate limbs because we never had the reason to! Think about the number of reasons why you would have to regenerate limbs in nature? Lion bit it off? Not sure that when a lion was around to bite off your limb it actually left you to live your life anyways, so we would have ended up evolving techniques to avoid lions in the first place, rather than let them bite off our limb and then develop techniques to grow it back.. Sure its actually possible that regeneration is not conserved because of energy constraints, but I highly doubt it..\n\n > But what if we had always had easy access to nutritious, calorie-rich food?\n > In another way of asking the question, is it possible to engineer an organism that had superpower-like bodily functions at the expense of it needing lots of food?\n\nI think we already have an example of an organism with superpower-like functions at the expense of needing lots of food: US. We eat a lot more than we should also because of the increased brain-size and processing power (I think).. \n\nI mean we already eat too much food, and we eat it too often. We have obviously evolved already to a large extent to conditions of abundant food supply. \n\nIn nature though there are places where food supply is not a huge problem *per se*. A glaring example is the tropics and a glaring example of evolution not caring about food are the birds of paradise. They seriously don't bother anymore about better methods of getting food do they?\n\n > EDIT: here's another one: could you create an organism that never slept, but instead ate tons of food to compensate?\n\nFrom whatever sleep-research has shown (and what I made out of it), sleep appears to be a fundamental requirement in the way brains work in general (not just human brains) and hence this might not be all that likely.."
]
}
|
[] |
[] |
[
[],
[]
] |
|
f9dg2y
|
what is the culture around modifying cars and motorcycles to be louder?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/f9dg2y/eli5_what_is_the_culture_around_modifying_cars/
|
{
"a_id": [
"fiqs43a",
"fiqt38j"
],
"score": [
2,
2
],
"text": [
"Most of the times making a motorcycle louder can save a life. Loud pipes save lives when comes to two wheels.",
"Depends on the individual\n\n1. Some (often younger) think louder = cool. These are often the ones that drill holes in their exhaust to achieve that effect\n\n2. Some (often incorrectly) think the power gains achieved by increasing the size of the exhaust or removing sections of it (often those used to clean the air before it goes into the atmosphere) are worth it\n\n2b) You can swap an exhaust to gain power but still keep it quiet, and light \n\n3. Some do it purely to create a deeper, throatier noise that they prefer and will, legitimately, enjoy the driving experience far more\n\n1 and 2 is usually illegal. If you hear “pops and bangs” then it’s probably achieved through over-fuelling the car and removing a catalytic converter. \n\n3 is usually a case of swapping to an aftermarket exhaust and would be done on a car with a big engine (in terms of displacement - say 4L and above). For some, it’s a big deal\n\nThere’s a thread/blog somewhere online where someone went through about a dozen high-end, custom exhausts on a Porsche GT car in order to try and get the “perfect” sound"
]
}
|
[] |
[] |
[
[],
[]
] |
||
18xk42
|
Is it possible to transmit data over something other than the electromagnetic spectrum?
|
With the government and the telecom companies saying how the spectrum is too crowded, I was wondering if theoretically there was another way to transmit data wirelessly.
|
askscience
|
http://www.reddit.com/r/askscience/comments/18xk42/is_it_possible_to_transmit_data_over_something/
|
{
"a_id": [
"c8iwffl",
"c8iwomj"
],
"score": [
4,
3
],
"text": [
"Here's two alternatives (with terrible latency):\n\n[FedEx](_URL_0_)\n\n[IP over avian carrier](_URL_1_)",
"Gravitational Waves!! \n\n_URL_0_\n\nWhile legit (it comes from DARPA), Any body who know anything about gravitational waves knows this proposal is ridiculous. "
]
}
|
[] |
[] |
[
[
"http://what-if.xkcd.com/31/",
"http://en.wikipedia.org/wiki/IP_over_Avian_Carriers"
],
[
"http://www.zyn.com/sbir/sbres/sttr/dod/darpa/darpa13a-003.htm"
]
] |
|
2am3py
|
how do i upload a website?
|
Assuming I've created a website in Dreamweaver, and I've also purchased a domain name, whats the best way to upload a website?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2am3py/eli5how_do_i_upload_a_website/
|
{
"a_id": [
"ciwit7k"
],
"score": [
3
],
"text": [
"You haven't mentioned your hosting solution, so I'm assuming you don't have one.\n\nA domain name is just a pretty name that you use so that people don't have to remember an IP address. That's it. It does nothing else for you. (Well not for a simple website, anyway.)\n\nWhatever Dreamweaver crapped out is the code. (By the way I heartily recommend building a website properly, tools like dreamweaver make websites that are really hard to maintain or modify and are generally total crap for Google or other search engines to understand and index.)\n\nSo what's missing? Well something to actually send the code to people's browser when they try to visit your website. A server. \n\nWhat you need to do is find a hosting company, buy a package from them and use the control panel on the DNS provider you got the domain name from to set up an A record containing the IP address of the hosting server. (The hosting company will give you the IP somewhere.)\n\nAfter that you'll probably need to SSH into the server, set up Apache, nginx or LigHTTPD and FTP, then use the FTP server to move the files into the root directory of the web server you set up.\n\nIf this is all flying over your head, as it probably is, you should secure the services of a web developer to help you. (And well your're at it probably ask them to do the website by hand.)\n"
]
}
|
[] |
[] |
[
[]
] |
|
3f7fbe
|
why does netflix produce original content? isn't it a risky endeavor? what are they gaining by trying to be a streaming service and a production studio?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/3f7fbe/eli5_why_does_netflix_produce_original_content/
|
{
"a_id": [
"ctlzfjp",
"ctlzg7m"
],
"score": [
3,
7
],
"text": [
"If they produce original content they can guarantee *exclusive* access to potentially highly sought after tv shows.\n\n\nTake HBO. People subscribe to channels like HBO because of the high quality content they produce. Netflix wants people to choose them over rivals such as lovefilm/amazon-prime etc. by offering new content that none of the other services can offer.",
"It is potentially risky, but ultimately, when their core business is based on licensing agreements (which piss off a lot of people when stuff disappears due to licensing), if they can keep costs reasonable, having something in their control is meaningful, and it will likely always be available on the streaming service.\n\nYou could have said the same thing about HBO 25 years ago. At that point, I think standup comedy specials were the bulk of their original programming, and Netflix is very similar to HBO (they are a subscription service, and they likely get more per month per customer than HBO does). Then all of a sudden HBO becomes the go-to place for shows that aren't watered down by the FCC, and milquetoast boring shows to appeal to the broadest audience, and they win tons of awards."
]
}
|
[] |
[] |
[
[],
[]
] |
||
1nsfyn
|
How many photons are hitting my eye?
|
askscience
|
http://www.reddit.com/r/askscience/comments/1nsfyn/how_many_photons_are_hitting_my_eye/
|
{
"a_id": [
"cclpt1u",
"cclr09t"
],
"score": [
8,
4
],
"text": [
"The first question is pretty hard to answer. 'Brightness' is not the only thing that matters. In fact, what humans usually describe as 'brightness' is just contrast (ie, we perceive something as bright because things around it are dark, not because it emits a lot of light.) So I will stick to something simple, a 60W incandescent lightbulb. Lets assume this lightbulb is the only source of light. Incandescent bulbs emit only about 10% of their light as visible light, most of that as red light.\n\nAll the light from the lightbulb cant possibly hit your eye. If you're about 5m away from it, and your eye is about 3cm across, and the room reflects no light (ie - the only light coming to your eye is directly from your lightbulb) then at this distance your single eye absorbs 0.0001068 Watts of photons!\n\nNow we have another problem. How many photons are stopped by the eye tissue before reaching receptors? Seems to be around 90%. [1]\n\nSo 0.00001 Watts, or 1% of 1% of a single Watt, are reaching the receptors of your eye. But from personal experience, you know you can see a 60W bulb clearly from 5m away. Your eye must be extremely sensitive! Your own body emits 40-80W of light as infrared - if humans could see infrared, we would all be blinded by our own glows.\n\nRed light as a wavelength of about 0.7 micrometers, or 700 nanometers. At this wavelength, each photon has 1.75 eV (electron-volts) of energy - or 2.8 * 10^-19 Joules. Now it is just as simple as dividing total energy by energy per photon to get total photons. The result, is 3.57*10^13 photons reach your eye every second.\n\n\nAs for the second question, it depends on what you mean by 'detect'. If you mean the receptors themselves detecting the light, then it is a remarkably low number - a rod will respond to a single photon. [1]\n\nIf you mean, you yourself perceiving a light source, I recall that question being asked on this subreddit before recently. I can't find it now, but the argument went something like this - the faintest things we can see are distant stars, and the individual calculated the light that must reach us from the dimmest star which can be seen with the naked eye. It was something around 10000 photons / sec (this is all from memory).\n\n[1] _URL_0_",
"This is a nuanced question.\n\nIt not only depends on 'amount of photons' but also the wavelength of light.\n\n\"how many photons do there have to be before I can detect a light?\" is a complicated question because there are many different types of photoreceptors in your eye, not all of which contribute to 'conscious vision'.\n\nFor instance, intrinsically photosensitive retinal ganglion cells (ipRGCs) are non-image forming photoreceptors that respond to low intensity light with short wavelengths. These cells relay information back to the 'master circadian clock' in the suprachiasmatic nucleus of the hypothalamus, thus entraining circadian rhythms to the natural light dark cycle.\n\nRods and cones differentially respond to different wavelengths, and different intensities, and contribute to vision as well as (slightly) to circadian entrainment.\n\n"
]
}
|
[] |
[] |
[
[
"http://math.ucr.edu/home/baez/physics/Quantum/see_a_photon.html"
],
[]
] |
||
1nqai2
|
How was news broken to the public that WWI was over?
|
Did the public know before the armistice was signed or was it published in newspapers exactly on 11/11?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1nqai2/how_was_news_broken_to_the_public_that_wwi_was/
|
{
"a_id": [
"ccl3t0u"
],
"score": [
4
],
"text": [
"Nobody really knew that the war was going to end on 11/11 except for the participants of the meeting. In fact, even the soldiers did not really know that the war had ended until the middle of the day or even later, depending on when the telegram reached them. Fighting was still continuing right up until the official cease fire and beyond, which happened six hours after the armistice was signed. On a side note, it is suggested that American soldier Henry Gunther was the last soldier to be killed during World War One (in [this](_URL_1_) article, for example), but the sources do differ and I personally believe different.\n\nThe armistice was signed at 6am on the morning of November 11th, so there was still time for the news to reach the morning newspapers, and so on many front pages the news did break to the world on 11/11. My favourite headline (or subheading really) for the end of the war was in the Daily Local News that simply says 'Put The Date Down Firmly - Write it November 11 1918' (which can be seen [here](_URL_0_)). It came to be that most people found out from the morning headlines or word of mouth. During the war, newspaper was a very big form of communicating the news (as obviously there were no TVs and radio was unreliable), so for many this was the first time they knew that the war was over. They may have had an idea that the war was coming to an end based on previous headlines, but they did not truly know the war had ended until that morning."
]
}
|
[] |
[] |
[
[
"http://imperialantiques.biz/yahoo_site_admin/assets/images/DSCF0819.18583458.JPG",
"http://news.bbc.co.uk/1/hi/magazine/7696021.stm"
]
] |
|
3r2byw
|
why does trying to read a scratched cd/dvd pretty much freeze up your computer?
|
Seems to have happened on pretty much every computer I've owned, what causes this?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/3r2byw/eli5_why_does_trying_to_read_a_scratched_cddvd/
|
{
"a_id": [
"cwkbdwv"
],
"score": [
17
],
"text": [
"Some things on a computer are never expected to take much time, so it sends the command to do it then just sits and waits for the result.\n\nWith a scratched CD/DVD the drive itself decides to try again over and over before giving up. The computer just sits there and waits. And waits. After a short timeout the drive gives up and moves on to the next sector of the disk. Unfortunately typical scratch damage affects tens or hundreds of sectors, so it all happens again, time after time and that short timeout gets multiplied up to much more.\n\nThe computer will have it's own timeout set after which it will give you a message about a problem reading the disk. This timeout is a balance between giving up too early and not managing to read an important disk that could have been recovered, and waiting too long and being really annoying.\n\nA defensively written program can handle it much better and give up on bad sectors more quickly, but most people don't do that, or can't justify the extra time it takes even if they know how to. It's only really worth the added complexity for things like data recovery programs which need to get back all the 'easy' sectors first before going back and retrying the bad ones.\n"
]
}
|
[] |
[] |
[
[]
] |
|
503h1e
|
why do professional field sports use cleats?
|
Now, I know that cleats obviously provide more traction, and definitely provide an advantage over someone that isn't using cleats. But if everyone is using cleats, no advantage is gained.
Cleats also seem to drastically increase the risk of leg injuries in sports. It seems like the vast majority of leg injuries happen when force is applied to the leg in an odd direction, and the cleats anchor the foot to the ground, so the leg can't naturally give. This means something else has to give, which is going to be some bone/muscle/tendon that is the weakest point in the leg. It seems like if an athlete was wearing non-cleated shoes, the chance that their foot would just slide out, avoiding injury for the leg, would be much greater.
Also, leg injuries usually tend to be the most likely to end an athletes career, no matter what the sport, so you would think avoiding leg injuries would be a priority for any sporting organization.
So, why the hell haven't cleats been banned? Do they not actually increase injuries that much? If they do increase injuries, no advantage is gained by using them, since all teams use them. If no teams used them, the playing field would still be level. What gives?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/503h1e/eli5_why_do_professional_field_sports_use_cleats/
|
{
"a_id": [
"d70vw0m",
"d70z0at",
"d717ife"
],
"score": [
5,
3,
3
],
"text": [
"They do not actually increase injuries much because it is against the rules to kick or step on your opponent, thus meaning it rarely happens. But they do prevent a lot of injuries by reducing your chances of your feet slipping on the grass. \n\nYour assumption of your foot being able to \"just slide out\" is true, but that causes more injuries instead of reducing them. ",
"Everyone having the same advantage doesn't remove the advantage. Everybody still has better traction. ",
" > So, why the hell haven't cleats been banned? Do they not actually increase injuries that much? If they do increase injuries, no advantage is gained by using them, since all teams use them. If no teams used them, the playing field would still be level. What gives?\n\nTwo big reasons. \n\nRemoving cleats actually would likely increase injuries. Slipping is dangerous and likely to cause lots of pulled muscles. Like you are right, in some ways. ACL injuries might go down without cleats (I am not positive about this though because I could see it also causing them) but overall injury rates would likely go up without cleats.\n\nSecond big reason is it makes the game more fun to watch, watching people slip as they cut and fumble around would be dumb compared to now. Pro sports are about entertainment afterall and people slipping all over the field especially if its wet is less entertaining."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
2wverz
|
Are there any instances of Viking cowardice or surrender?
|
I've been reading up on the Vikings and noticed that they held a young death in battle to be the highest honour, but they also have been defeated in battle. I'm wondering whether they have ever surrendered, fled or deserted.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/2wverz/are_there_any_instances_of_viking_cowardice_or/
|
{
"a_id": [
"coukjbk",
"coukpwf",
"coulap6"
],
"score": [
17,
4,
4
],
"text": [
"At Ridgeway near [Weymouth](_URL_0_) on the English Channel, archaeologists recently uncovered the bodies of about 50 vikings. That is, they found a pile of [47 skulls](_URL_2_) next to [52 skeletons](_URL_1_).\n\nSome initial analysis has been done of trace elements in their bones, which show that they grew up in many different places, such as the Arctic and sub-Arctic areas of Scandinavia, northern Iceland, the Baltic States, Belarus and Russia. But by about three years before their deaths, they were all started eating a similar diet heavy in fish. In other words, this is a viking crew that was somehow captured and executed, probably late in the Viking Age around 1000.\n\nInterestingly, there are few suggestions that these men fought or put up much resistance prior to their executions. There are no serious wounds that would suggest surrender in battle. These men were somehow captured without a fight.\n\nThe chop marks on the backs of the vertebrae and jaw bones show that these executions were messy. There's no suggestion that they were tied or otherwise bound, but some individuals did try to turn away from the blow, which only prolonged their suffering. Others took two or three poorly placed blows before the sword or axe finally severed their heads.\n\nWhoever executed these vikings was proud of it, and they kept 3-5 heads as trophies. (There's some difficulty in getting an exact count of the jumbled bones.) This is reminiscent of the Norse practice of displaying skulls on city walls like at Dublin (human skulls found beneath the Viking Age ramparts) or on the outside farm walls as at Hofstađir, Iceland (these were cattle skulls).\n\nThe images of the Ridgeway burials are also eerily reminiscent of the bones stacked at [Repton](_URL_3_), which a viking army occupied in the winter of 873-874. Of course, there's little consensus as to weather the Repton burials were actually a reburial of bodies the vikings dug up when they occupied the monastery, whether they were dead members of the viking army, or whether they were people the vikings had executed. There's only been some isotope analysis, and the results were inconclusive and mixed.\n\nSo is this a viking crew that struggled without a fight and met a gruesome end? Almost certainly. But who executed them, when, and why? These questions are harder to answer ... but that's why I love studying archaeology!",
"\"Cowardice\" is a rather unclear term, but vikings surrendered on multiple occasions. The history of the British Isles provides several examples, for example in 980 Irish forces had crushed King Olaf's viking forces while besieging Dublin, and forced him to surrender and leave the country.\n\n*A History of the Vikings* - T. D. Kendrick",
"There have been instances of Viking surrender recorded in *The Anglo Saxon Chronicle* from the 870s-880s during the reign of King Alfred. In 878, Danish forces led by King Guthrum fled the field of battle to a fortress where Alfred besieged them for a fortnight after which the Danes surrendered, gave high-ranking hostages and promised to leave Alfred's lands. Guthrum also sought Alfred's sponsorship in baptism. In 882, Alfred's forces engaged four Danish ships in a sea battle, two of which surrendered, while the other two were taken with all occupants slain. "
]
}
|
[] |
[] |
[
[
"https://www.google.com/maps/place/Weymouth,+Dorset,+UK/@50.6268352,-2.4578246,12z/data=!3m1!4b1!4m2!3m1!1s0x487257fd62333533:0xebeb17fada5f4737",
"http://www.medievalists.net/wp-content/uploads/2012/11/4459323745_4e76081aed_b.jpeg",
"http://thehumanjourney.net/images/stories/images/weymouth/2ndpost/shot%201506.jpg",
"http://archeurope.eu/uploads/images/Viking/Repton/repton01l.jpg"
],
[],
[]
] |
|
7np47c
|
What caused the sudden change to shaved pussy in porn starting in the 1990s?
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/7np47c/what_caused_the_sudden_change_to_shaved_pussy_in/
|
{
"a_id": [
"ds3g0az"
],
"score": [
2
],
"text": [
"Hi,\n\nCould you please resubmit this without the coarse language in the title? (Why did porn stars start shaving, or some such)\n\nThanks!"
]
}
|
[] |
[] |
[
[]
] |
||
3lzu5p
|
why does water seem to stick to glass?
|
More specifically the water I put in glass test tubes. When I pour it down the drain in notice there's still a noticeable amount left that's kinda difficult to get rid of. We use these other vials for testing and I've noticed the same thing with them too (they're made of borosilicate, not sure about the test tubes).
I don't seem to notice this when washing dishes at home though.
|
askscience
|
https://www.reddit.com/r/askscience/comments/3lzu5p/why_does_water_seem_to_stick_to_glass/
|
{
"a_id": [
"cvaqjku",
"cvawcbr",
"cvb6rry"
],
"score": [
46,
12,
4
],
"text": [
"[Adhesion.](_URL_0_) Water \"seems\" to stick to glass because it does.\n\n > I don't seem to notice this when washing dishes at home though.\n\nIt certainly still does, but (a) possible you're looking at non-transparent dishes so you're not really noticing it, and (b) soap in the water will massively reduce the surface tension and reduce surface adhesion.",
"The short answer is that glass--an amorphous compound containing primarily silicon and oxygen--tends to form something known as silanol on its surface. These silanol groups are Si-OH formed when oxygen atoms dangling from the surface of the SiO4 matrix react with moisture in the air. They form hydrogen bonds with liquid water, causing it to adhere to the surface of the glass very strongly. This won't happen as much with dishes and cookware because they often receive special coatings (e.g. PTFE/Teflon) specifically to prevent this adhesion. ",
"Polarity of water by hydrogen bonding. It's kind of like a tiny weak magnet with a constantly changing positive and negative charge. Thus making it stick to its self and other objects, and giving rise to its surface tension. "
]
}
|
[] |
[] |
[
[
"https://en.wikipedia.org/wiki/Adhesion"
],
[],
[]
] |
|
6r92m9
|
if the speed of sound is about 340m/s how can normal things make sound?
|
Are our vocal cords moving at that speed? and even pressing keys on my laptop as slow as I can still make sounds
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/6r92m9/eli5if_the_speed_of_sound_is_about_340ms_how_can/
|
{
"a_id": [
"dl3d27d",
"dl3faw7"
],
"score": [
2,
2
],
"text": [
"No you are confusing the speed of propagation of the sound wave with the speed of the thing moving back and forth to generate the sound.\n\nWhile the thing moving back and forth doesn't have to move nearly as fast as the speed of sound, it does have to move much faster than you could say move your fingers. The highest frequency that a typical human can hear is 20kHz. To create that sound an object has to move back and forth 20,000 times a second. The lowest frequency we can hear is 20 Hz or 20 times a second. That's still much too fast for the average human to move their fingers. \n\nSo most of the sounds we create are by bumping or slapping objects and causes them to vibrate. Objects have a frequency that they tend to vibrate at based on their physical properties.\n\nTo finally answer your question, yes parts of your vocal cords are moving thousands of times a second to produce the sounds that come out of your mouth.",
"The speed of sound is related to how fast particles bump into each other, not how fast they travel. Keep in mind that air particles are constantly moving, they don't just sit around. \n\nThat said, the speed of the particles can be much higher than the speed of sound. \n\nWhen you hit something, like a key on your keyboard, the sound doesn't come directly from the motion of the key but rather the energy from friction and the impact dissipating through the material which causes it to vibrate very quickly. "
]
}
|
[] |
[] |
[
[],
[]
] |
|
2f5p5b
|
why do we not have international space program?
|
I can understand that many countries like keeping their civilian and military space programs separate but why do countries start and fund their own space programs? Wouldn't it be more beneficial to have one large space program that many countries fund rather than a number of small individually funded space programs?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2f5p5b/eli5_why_do_we_not_have_international_space/
|
{
"a_id": [
"ck65j0h",
"ck66c9l"
],
"score": [
3,
2
],
"text": [
"Yes, it it is typically more beneficial. That's why 20 nations have cooperated in the [European Space Agency](_URL_0_) for over 30 years now. ",
"**International Space** Station\n\nIt's even in the name."
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/European_Space_Agency"
],
[]
] |
|
1z7sc1
|
Why did the Great War produce so many soldier-poets? Was it simply the number of public school educated young men faced with enforced trench-based stasis? Or are there other factors?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1z7sc1/why_did_the_great_war_produce_so_many/
|
{
"a_id": [
"cfriz7e"
],
"score": [
141
],
"text": [
"**Poetry and the War**\n\nIt should be noted, first, that the war produced an absurd number of poets at every level -- not just in the trenches. Catherine Reilly's groundbreaking *English Poetry of the First World War: A Bibliography* (1978), for example, lists some 2,225 English poets publishing work about the war while it was going on, and soldier-poets were far from the majority -- 1,808 of this number were civilians. A quarter of the aggregate number were women, too, which is another fact often overlooked; it was only with a strong feminist turn in First World War studies in the 1970s that these many excellent poets were finally given their due. Prior to that, it was often very difficult to find their work at all unless they were power-house figures like Jessie Pope or Mary Borden, and even then it could be difficult; Brian Gardner's *Up the Line to Death: The War Poets 1914-1918* (1964), for example, set a bold new direction for the canon of the war's poetry, but among its seventy-two included poets (many justly being rescued from obscurity) there isn't a single woman. Anyway, this is something of a sideline to our main subject -- sorry.\n\nIt was popularly felt from the very start, at least in Britain, that the war demanded an extensive poetic response. We'll get to why that was in a moment, but it would first be worth examining just what that response looked like. In August of 1914, for example, the *Times* of London received upwards of a hundred submitted poems *a day* from its readers, with around a thousand finally having been published by the time the year was out. Anthologies of war-related poetry began coming out at once, often for the support of various charitable endeavours (such as the relief of Belgian refugees), and patriotic poetry readings were a popular public entertainment for young and old again. Sales were excellent, too; Kipling's *Barrack-Room Ballads* (first published in 1892) sold 29,000 copies in 1915 alone, and by the war's end the complete poetical works of Rupert Brooke -- then the most celebrated martyr from among the soldier-poets -- had sold some 200,000 copies.\n\nIt may surprise you to hear it, but the consolidation of a coherent poetic response to the war at the highest levels was one of the first tasks of Britain's first-ever official War Propaganda Bureau, based at Wellington House in Buckingham Gate. The Bureau put out a call as soon as the war was declared soliciting the immediate involvement of the biggest names in English literature, and on September 2nd of 1914 those figures met in what must have been one of the largest such gatherings of establishment literary figures in history. Everyone was there, or at least sent a representative -- Rudyard Kipling, Thomas Hardy, Sir Owen Seaman, G.K. Chesterton, Sir Henry Newbolt, the poet laureate Robert Bridges, the far-future poet laureate John Masefield, and many others besides (to say nothing of major figures known now mainly for their prose, like H.G. Wells, J.M. Barrie or Arnold Bennett). I could go on about all of this forever, anyway; interested parties can read [my recent piece on the subject](_URL_2_) at Oxford's WWI centenary project, *Continuations and Beginnings*.\n\n**Georgian Poetry and the Post-Victorian Cultural Milieu** \n\nNow, you've asked why there were so many soldier-poets, and suggested the role of education in the matter. This is a good start, and helps explain some of the enormous popularity of the poetic genre on a broader level. The passage of the [Elementary Education Act of 1870](_URL_0_) had seen the establishment of rigorous new standards for education throughout the realm, and one of the consequences of this was a significant boom in mass literacy. By the time the war began the first children to be subjected to the standards of the act were well into their adulthood, and they had as much of an appetite for poetry as their predecessors did -- but with a far greater ability (especially among the poor) to purchase and consume it privately. It was a market that inspired strong competition between authors and publishers, and authors already known as major public figures for their poetical works became more celebrated yet. The production and consumption of poetry was something of a national pastime, and the war provided a much expanded venue for poetical work in styles and on subjects both new and old.\n\nAt the war's outset, something exciting had been happening in the world of English poetry -- the birth of what was called Georgian lyricism. The Georgian movement (if we may call it that) had been spearheaded by the influence of the editorial team of Edward Marsh and Harold Monro; it was comprised of a varied collection of young, dynamic poets producing modern works that were simultaneously deferential to many of standards of Victorian poetry and experimental in their subjects, moods and approaches. My somewhat glib summation of the Georgian experience is that it would be like seeing Walt Whitman and Robert Browning engage in a fist fight that ended with them making out. In any event, they were, I repeat, thoroughly modern -- but it is easy to forget this in light of the triumph of the Modernists, who have rather swept the field were that sort of name is concerned.\n\nThe reason the Georgian movement matters to what we're considering here is that it was home to a number of authors whose names are now far more familiar to us in connection with the war -- names like Rupert Brooke, Siegfried Sassoon, Isaac Rosenberg and Robert Graves. The works of these authors appeared in Marsh and Monro's *Georgian Anthologies*, which first started appearing in 1912; Brooke was in from the start, and Sassoon, Rosenberg and Graves began to be included with the third volume in 1917 -- as much for their longstanding friendships with this entire literary circle as for the power of their works. Some of the most famous of the war poets, then, do not necessarily emanate strictly from the trenches, but rather fit into a large and pre-existing literary movement that was already increasingly popular.\n\nThis doesn't necessarily explain the popularity of *all* of the soldier-poets, and certainly does not explain their proliferation during the course of the war. I'd wager that few unpublished souls would have intently scanned the lines of the *Georgian Anthologies* while waiting out a barrage near Ypres and thought, \"that could be *me*.\" So what was it?\n\n**Competing Theories**\n\nA number of theories have been proposed, and I don't know that any one of them offers a total explanation for the huge presence of this sort of poet on the war's literary scene. Certainly there's the huge appetite for poetry already described, and the attendant curiosity on the reading public's part about poetical works being produced by those experiencing new and titanic events. But this public literacy was not a solitary affair; this was the first national army in British history that was itself broadly literate even (mostly) down to the lowest ranks, and this offered a much larger scope for written reflection on the soldier's part than had previously been likely in the wars of ages past.\n\nCertainly the possibility you mention in your question is a compelling one as well -- life in the trenches, as is often the case in modern war, could be described as long stretches of boredom punctuated by moments of appalling terror and danger, and this provided many soldiers with the sort of time necessary for poetic reflection and refinement while simultaneously confront them with the sort of experiences and images that could inspire the kind of response that has now become so famous. \n\nPursuant to this, it is popularly and often said that the soldier-poetry of the war is born of an intense need to express the inexpressible -- to cross the gap that existed between the home front and the firing line in a way that allowed communication between the two worlds, and for those still at home to receive a vivid and \"truthful\" impression of what was being seen, experienced and felt at the fighting front. The degree to which this information was otherwise prevented from reaching civilians by censors, propagandists and the like has been somewhat exaggerated in the intervening years, but it remains the case that many of the war's poets felt themselves to be in reaction to the glib emptiness of newspaper prose or the appalling vulgarity of patriotic music-hall expression. \"All a poet can do today is warn,\" wrote Wilfred Owen in [his preface](_URL_1_) to an intended anthology of his poems -- it was never compiled, at least by him, as he was killed a few days before the war ended in November of 1918.\n\nWhatever the cause of their popularity at the time, this question of perceived \"honesty\" has been a hugely important factor in the soldier-poets' persisting popularity. Ernest Hemingway, in an introduction to a collection of war writing in 1942, insisted that the work of the soldier-poets was essentially the only good and true work to come out of the war at all; \"one reason for this,\" he continued, \"is that poets are not arrested as quickly as prose writers would be if they wrote critically since the latter’s meaning, if they are good writers, is too uncomfortably clear.\" For Hemingway, the writer needed to be \"of as great probity and honesty as a priest of God\" -- while many of the war's soldier-poets were, many of the prose writers and patriotic poets of the war, in his estimation, were not. Whether this is actually the case (I would argue that it's a massive oversimplification), it's a perspective that remains common where popular comment on the poetry is concerned: there is propaganda on the one hand, and the unmediated experience of the war, as presented by the soldier-poets, on the other. It's what saw Virginia Woolf praise Sassoon's first volume of war poems in 1917 as being work which makes civilian readers say \"'Yes, this is going on; and we are sitting here watching it,' with a new shock of surprise, with an uneasy desire to leave our place in the audience.\" It is work that inspires, but also convicts, in a way that so much of the war's patriotic home-front poetry now fails to do -- not, I would argue, because it was always incapable of so doing, but because we are now cut off from the concerns that motivated it in a way that we are not when it comes to the soldier-poets' dark lyrics of fear, pain, disappointment, and all-conquering irony.\n\n**Final Thoughts and a TL;DR**\n\nIn closing, I'll note that the most popular anthology of soldier-poetry in English during the war was [E.B. Osborn's *The Muse in Arms*](_URL_3_) (1917); it included the work of over a hundred poets, of whom almost all were on active service when they wrote their works. It sold well, and contains many names (like Graves and Sassoon) who have now become famous. In Osborn's preface, however, he offers a start warning that serves, even at that early stage, as a fitting summation of all that I have said above:\n\n > Of all the vast mass of civilian war-verse, very little indeed will survive; [. . .] it has nearly all been cast ere now into the waste-paper basket of oblivion. The making of verse memorials is perhaps the only task to which the non-combatant poet may address himself without fear of losing his sincerity...\n\nThis anxiety over sincerity has haunted the ongoing reception of the war's poetry ever since it first started to appear, and I don't see that ending anytime soon. It, as much as anything, accounts for some of the soldier-poets' popularity.\n\n**TL;DR:** The war produced a lot of poetry full-stop, but the work of the soldier-poets is among the most popular that remains because of its lingering immediacy when compared to the patriotic homefront works that often focused on ideals and concerns that we find difficult now to share. The war's poetry was produced both in and by an atmosphere of greatly increased mass-literacy, and in a cultural atmosphere in which responding to major events with poetry was not only common but expected."
]
}
|
[] |
[] |
[
[
"http://www.educationengland.org.uk/documents/acts/1870-elementary-education-act.html",
"https://www.oucs.ox.ac.uk/ww1lit/education/tutorials/intro/owen/preface.html",
"http://ww1centenary.oucs.ox.ac.uk/unconventionalsoldiers/propaganda-the-authors-declaration/",
"https://archive.org/details/museinarmscollec00osbouoft"
]
] |
||
jj0w3
|
How does science define and/or account for the perception of 'luck'?
|
Is luck nothing more than a construct? Is it measurable? We seem to talk about luck a lot in our lives but what does science have to say on the matter?
|
askscience
|
http://www.reddit.com/r/askscience/comments/jj0w3/how_does_science_define_andor_account_for_the/
|
{
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"Human beings excel in identifying patterns to the extent that we often see patterns that are not actually there.",
"Scientists love probability. We'll repeat experiments to determine if there are multiple outcomes, and (with enough measurements), the probability of each.\n\n\"Luck,\" however, is a purely human construct. People have evolved to find patterns in everything. (\"Don't go near crocodiles; they'll eat you\" is an evolutionary-selected-for pattern to find.) Because of that, we find patterns where there are none. Luck is an expression of that tendency.",
"[Article on luck](_URL_0_)\n\nNot the journal article, but a good start?",
"The hard science perspective dismisses any form of luck as a tangible effect. It is certainly the case that probability plays no favorites. However, it is certainly *not* the case that luck is completely explained as a matter of inaccurate narratives. \nQuotientSpace linked to a report of the most comprehensive \"luck study.\" The researcher gathered subjects who considered themselves extremely lucky or unlucky and tested them in various ways. In tests where there was a hidden piece of information or reward presented in a way that was secondary to the primary task, lucky people were much more likely to find it, whereas unlucky people were overly focused on the task at hand. Lucky people were also much more likely to have sources of novelty in their life, while unlucky people were far more routine-oriented. \nSo, lucky people don't somehow bend the laws of math. But they do have a mindset and activity pattern that promote the creation of opportunities, and they have the open-mindedness to recognize and pursue those opportunities, resulting in an overall increase of positive flukes and things going right.",
"Human beings excel in identifying patterns to the extent that we often see patterns that are not actually there.",
"Scientists love probability. We'll repeat experiments to determine if there are multiple outcomes, and (with enough measurements), the probability of each.\n\n\"Luck,\" however, is a purely human construct. People have evolved to find patterns in everything. (\"Don't go near crocodiles; they'll eat you\" is an evolutionary-selected-for pattern to find.) Because of that, we find patterns where there are none. Luck is an expression of that tendency.",
"[Article on luck](_URL_0_)\n\nNot the journal article, but a good start?",
"The hard science perspective dismisses any form of luck as a tangible effect. It is certainly the case that probability plays no favorites. However, it is certainly *not* the case that luck is completely explained as a matter of inaccurate narratives. \nQuotientSpace linked to a report of the most comprehensive \"luck study.\" The researcher gathered subjects who considered themselves extremely lucky or unlucky and tested them in various ways. In tests where there was a hidden piece of information or reward presented in a way that was secondary to the primary task, lucky people were much more likely to find it, whereas unlucky people were overly focused on the task at hand. Lucky people were also much more likely to have sources of novelty in their life, while unlucky people were far more routine-oriented. \nSo, lucky people don't somehow bend the laws of math. But they do have a mindset and activity pattern that promote the creation of opportunities, and they have the open-mindedness to recognize and pursue those opportunities, resulting in an overall increase of positive flukes and things going right."
]
}
|
[] |
[] |
[
[],
[],
[
"http://www.richardwiseman.com/resources/The_Luck_Factor.pdf"
],
[],
[],
[],
[
"http://www.richardwiseman.com/resources/The_Luck_Factor.pdf"
],
[]
] |
|
1o12v5
|
What are some weird fads of the 1900's that most people don't know about?
|
For example: [Pole-sitting](_URL_0_) was a fad in the 1920's
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1o12v5/what_are_some_weird_fads_of_the_1900s_that_most/
|
{
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"text": [
"For a short period after the turn of the 20th Century, it became quite fashionable for wealthy New York City socialites to carry around \"companion monkeys,\" which they would dress in outfits and keep in their [muff hand warmers](_URL_0_). Thousands of monkeys were brought into the city in the first decade of the 20th Century, and there are records of pet monkeys throwing flowerpots and setting houses on fire. A very [interesting article](_URL_1_) from The Sun notes that \"to be able to talk monkey, just as people once talked horse or dog, is a mark of being up to date. To be able to take up a strange monkey, look him over and then calmly put him down and tell how old he is, where he came from, what are his habits and what his possibilities is a part of one's social education.\" Wow. That said, the trend was relatively short lived, fading into obscurity after 1910 as Pomeranian dogs became the newest \"it\" accessory. ",
"Billikens. Today the Billiken survives primarily as the mascot of the St. Louis University athletic teams, but around the period 1908-1920, they were a national craze. A biilliken was a little Buddha-like charm doll that was supposed to be \"the god of good luck,\" or, as their creator Florence Pretz styled him, \"the god of things as they ought to be.\" In 1908 she patented the figure as such (becoming the first to patent a god) and the little guy sold in the millions, as charm bracelets, dolls, shelf ornamentals, etc., as well as the subject of at least two hit songs. \n\n[Primary source](_URL_1_)\n[Secondary source 1](_URL_0_)\n[Secondary source 2](_URL_2_)"
]
}
|
[] |
[
"http://en.wikipedia.org/wiki/Pole-sitting"
] |
[
[
"http://4.bp.blogspot.com/-5E-8UfoED3w/UMdQHxtjIEI/AAAAAAAAMUk/yiH9clLFRoE/s400/monkey.jpg",
"http://chroniclingamerica.loc.gov/lccn/sn83030272/1907-03-31/ed-1/seq-48/"
],
[
"http://abigailpadgett.wordpress.com/2012/07/14/traveling-for-stories-3/",
"http://www.churchofgoodluck.com/Florence_Pretz.html",
"http://unewsonline.com/2008/09/25/billikencelebratescentenial/"
]
] |
|
1zzx27
|
how does the large hadron collider remain stable?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1zzx27/eli5_how_does_the_large_hadron_collider_remain/
|
{
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"You need to elaborate more on your question. What fo you mean by remaining stable?",
"I *think* the collision experiments themselves release only tiny amounts of energy. No chain reactions like fusion or fission are possible. If the particles miss each other, it's just one radiated particle. Which are all around us anyway. That, and union welding."
]
}
|
[] |
[] |
[
[],
[]
] |
||
24rq2l
|
What is the origin of the modern conception of a 'franchise' business model?
|
I'm interested to know the origins of the modern concept of a franchise, how it became a business model, and if there is a historical context to understand franchising that dates back to before the modern conception of franchising (McDonalds, hotels, etc).
My first AskHistorian question, big thanks to the experts and academics that made this sub possible!
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/24rq2l/what_is_the_origin_of_the_modern_conception_of_a/
|
{
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"_URL_0_\n\nIt was none other than Colonel Harland Sanders who started the idea. In 1955 he was able to convince a friend of his in Utah to start selling fried chicken and fixings using his recipe and cooking the chickens in a pressure cooker. The link above is his autobiography and from the KFC website but I see no reason to disbelieve any of it. It's actually a really good read. Chapter nine is the part you will be most interested in. The original deal was Col. Sanders would receive a nickel for every chicken sold.\n\nThat went so well that Col. Sanders spent the next several years driving all over the USA and Canada making a similar deal with small time diner owners all over the country. \n\nOn another interesting note. It's through KFC that Dave Thomas, of Wendy's fame, got his start \n\nA & E's show Biography did episodes about both Col. Sanders and Dave thomas. Both fascinating american businessmen. I can't look at You Tube where I am at, but you may be able to find those. ",
"The idea of the corporate franchise as we know it today can be traced back to Ray Kroc, the man who bought out the McDonald's brothers, and his expansion of the brand. The book [*Fast Food Nation*](_URL_2_) covers the topic fairly well. Prior to the corporate franchise the closest was the rise of the [department](_URL_3_) [store](_URL_1_) and the [catalog store](_URL_0_). The industrial production of standardized goods allowed stores to stock the same product repeatably and rail and river/canal shipping could distribute the product to multiple locations. \n \n[I've writtend a few papers on Kroc and Sears. Sears in particular is well studied and documented due to its product variety and widespread influence on the American mid-west... they sold and shipped houses by catalog, for example]",
"Isaac Singer used franchise dealers in the 1850's. He wanted to expand his sewing machine business but lacked the money to expand both manufacturing and distribution. He sold franchises to retailers who would have exclusive rights for that area and in exchange he got the money needed to expand his factories.\n\n_URL_0_\n\n"
]
}
|
[] |
[] |
[
[
"http://www.kfc.com/images/pdf/ColonelSanders-Stories.pdf"
],
[
"http://www.amazon.com/Sears-Roebuck-U-S-A-American-Catalog/dp/0812823141/ref=sr_1_4?ie=UTF8&qid=1399310956&sr=8-4&keywords=history+of+sears+roebuck",
"http://www.amazon.com/American-Department-Store-Transformed-1920-1960/dp/0300149387/ref=sr_1_3?s=books&ie=UTF8&qid=1399311047&sr=1-3&keywords=history+of+department+stores",
"http://www.amazon.com/Fast-Food-Nation-All-American-Doing-ebook/dp/B003G83UI2/ref=sr_1_1?ie=UTF8&qid=1399310449&sr=8-1&keywords=fast+food+nation",
"http://www.amazon.com/History-Department-Store-William-Ferry/dp/B0000CL1ZZ/ref=sr_1_10?s=books&ie=UTF8&qid=1399311047&sr=1-10&keywords=history+of+department+stores"
],
[
"http://www.sba.gov/community/blogs/how-franchising-began"
]
] |
|
7zq7bf
|
What are some good databases for US newspapers?
|
Especially databases that include the big papers such as the new york times etc. Reason: I'm researching how papers wrote about the Pentagon papers and the reaction of US citizens.
Thanks in advance!
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/7zq7bf/what_are_some_good_databases_for_us_newspapers/
|
{
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"text": [
"I use _URL_0_ - the search feature is solid and it includes the Times.",
"Proquest historical newspapers has a few interesting ones including the Times. My city library has access to a few of the titles, university libraries will often have most of them."
]
}
|
[] |
[] |
[
[
"newspapers.com"
],
[]
] |
|
dvp0zk
|
Can someone explain to me if there will be new habitable areas as global warming and climate change progress?
|
I’m basically wondering if those areas, such as most of Russia will become habitable. These areas are so cold now, but with the warmth they may become much warmer and possibly habitable, in my mind. Thus leading for new possible areas for crops to grow. Can someone explain why this IS or IS NOT the case.
*I USE RUSSIA AS AN EXTREME EXAMPLE* it could be as little as Canada becoming warmer and Canadians having the ability to grow corn to an extant as someone in Iowa or Illinois.
|
askscience
|
https://www.reddit.com/r/askscience/comments/dvp0zk/can_someone_explain_to_me_if_there_will_be_new/
|
{
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"text": [
"It may make those areas more habitable in terms of temperature, but most of the land up there is permafrost, so you’d get massive amounts of erosion as the ice in the ground turns to water.\n\nPlus, if all the permafrost up there thaws, were pretty much boned. Currently the CO2 and Methane released by the thawing permafrost is about 10% of what humans are emitting, and that’s only going to increase as the temperature rises. We could get a pretty nasty runaway effect that we might not be able to deal with.",
"Yes, almost certainly new regions will become habitable at higher latitudes (both north and south). However, there are likely to be many, many regions rendered uninhabitable as they become inundated, transform into dust bowls, or subject to extreme weather events. Also, although climate change involves global warming on average, the actual distribution will be patchy. Some places will be come cooler on average, others warmer, others the same. The unpredictability of this is one of the challenges of climate change research."
]
}
|
[] |
[] |
[
[],
[]
] |
|
5ipvta
|
many in the u.s. are concerned for the future. can a modern, world super power actually fall similar to rome?
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/5ipvta/eli5_many_in_the_us_are_concerned_for_the_future/
|
{
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"text": [
"I question your premise. \n\nAnyway, the fall of rome was varied and slow. Yes there were actual conquests but a lot of it was gradual. \n\nWe probably don't have to worry about northern european hordes threatening us at the gate. \n\nWe probably do have to worry about a relative decline in power. But that wouldn't mean that the country fails or becomes undeveloped. \n\nSpain used to be the most powerful nation in the world, then France, then the UK. Citizens in all three countries are doing pretty well today even if their respective states have lost a lot of power/influence. \n\n"
]
}
|
[] |
[] |
[
[]
] |
||
1pluyc
|
why are they cutting food stamps in the us?
|
I obviously know it's a budget issue, but why are they cutting back on something like food stamps? Is this related to the Affordable Care Act?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/1pluyc/why_are_they_cutting_food_stamps_in_the_us/
|
{
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"text": [
"Edit 2: Since some people need further explanation, I do not claim that the views below are my own, nor do I claim that they are the correct way of thinking. What follows is just my understanding of the arguments presented by those who wish to cut back on expansion of food stamps in the US.\n\n\nThe reasoning behind it is as follows and I will do my best to leave my bias out of it. \n\n1. Food stamps are a drain on the countries resources. Doesn't matter how big or small the cost , we are paying for someone else's food. \n\n2. This is seen by some as a government handout that has been and will continue to be abused by individuals to the point where they decide to not work, and just live off of the government assistance. \n\n3. Even if the stamps were not abused, it is the opinion of some that we should not provide services like food stamps to people because not having it given to them will encourage them to work. \n\n4. Some people are also of the opinion that using tax dollars to fund programs like food stamps takes away from workers who earned their wage and gives it to people who do not deserve it. \n\nThose are the general ideas behind it, whether or not you agree with them is up to you. \n\nEDIT: words"
]
}
|
[] |
[] |
[
[]
] |
|
t539h
|
Is it possible that some human emotions and actions are influenced by viral, bacterial, or fungal infections?
|
I was reading the NPR Article ['Zombie' Ants And The Fungus That Saves Them](_URL_0_) and I started to wonder if humans could be under a similar influence when they make irrational decisions or experience irrational emotions.
I know this seems like a Dark Ages notion, but could a contagion be the true demon inside causing us to experience emotional states/thoughts not triggered by rational thought?
I understand that diseases like rabies exist but I'm curious if more subtle infections influence our daily lives and actions more than we currently credit.
|
askscience
|
http://www.reddit.com/r/askscience/comments/t539h/is_it_possible_that_some_human_emotions_and/
|
{
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"text": [
"Sure, google [toxoplasmosis.](_URL_0_)",
"[People become more social when infected with the flu, making them more likely to infect others](_URL_1_). One of my favorite studies.\n\nWell, the study actually tested the flu *vaccine*, but the effects should be similar... and this is fairly new research, so I'm excited to see what else turns up.\n\nEdit: I learned of this study from a [story in the Atlantic about toxoplasmosis](_URL_0_), which I'll quote:\n\"The difference in the subjects’ behavior before and after vaccination was pronounced: the flu shot had the effect of nearly doubling the number of people with whom the participants came in close contact during the brief window when the live virus was maximally contagious. “People who had very limited or simple social lives were suddenly deciding that they needed to go out to bars or parties, or invite a bunch of people over,” says Reiber. “This happened with lots of our subjects. It wasn’t just one or two outliers.”\"",
"[Here](_URL_0_) is a link to a Scientific American podcast (also contains a link to the study) about changes in behavior as a result to modification of the species composition of gut flora in mice. There is also a well-documented (if poorly-understood) connection between IBS/GI problems and anxiety/depression. The link is definitely there, but we're only just beginning to scratch the surface of the specific ways in which gut bacteria affect us. As other posters have mentioned, toxoplasmosis (infection by *toxoplasma gondii*) can profoundly change behavior in rats and has different, but still distinct, effects on humans as well. I think we can safely postulate that there must be a variety of viruses/bacteria/fungi/parasites that are capable of changing our chemistry and therefore influencing our behavior.",
"Not only emotions, but most definitely actions. Check out [PANDAS](_URL_0_) for some info on how Group A streptococcus infections lead to OCD and other mental health issues. Pretty interesting. This is very simplified, but if you look up PANDAS on pubmed there are some interesting reads.\n\nEdit: Typo",
"Absolutely.\n\nThere are many examples of infectious agents modulating host behavior to improve the chance of transmission. Someone on this thread already mentioned *Toxoplasma gondii*, which can make the rodents (and perhaps people?) that it infects unduly fond of cats.\n\nSyphilis used to be called \"Cupid's disease\" because the causative agent, *Treponema pallidum*, causes neurological damage that makes the host more...amorous. It's easy to see how that might be advantageous for a sexually-transmitted bug.\n\nThere's also some evidence that diseases transmitted by mosquitoes alter behavior of humans to make bites more likely. People with malaria often feel sicker at night, which is the same time of day that mosquitoes like to come out and feed. The evolutionary \"reasoning\" behind this is that people who feel sick are less likely to swat at biting mosquitoes, giving them a better chance of getting away and spreading the disease.\n\nI'm not a specialist in chronic infections that would extend the kind of long-term influence that I think you're getting at. But the idea is not far-fetched."
]
}
|
[] |
[
"http://www.npr.org/templates/archives/archive.php?thingId=103943429&date=5-2-2012&archiveAnchorId=151832911#archivestory151811170"
] |
[
[
"http://www.nytimes.com/2007/12/09/magazine/09_10_catcoat.html"
],
[
"http://www.theatlantic.com/magazine/archive/2012/03/how-your-cat-is-making-you-crazy/8873/?single_page=true",
"http://indiana.academia.edu/EricShattuck/Papers/531125/Change_in_Human_Social_Behavior_in_Response_to_a_Common_Vaccine"
],
[
"http://www.scientificamerican.com/podcast/episode.cfm?id=gut-bugs-affect-brains-11-05-20"
],
[
"http://en.wikipedia.org/wiki/PANDAS"
],
[]
] |
|
2ux8xh
|
we see stories of people who lose half their brain and somehow survive. if you divide a human brain 50/50 are both halves equally viable to survive as a person given the right circumstances?
|
example person with half a brain:
_URL_0_
apparently there is also a surgical procedure:
_URL_1_
*added links
*i am selecting kitten1999 post as the answer
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2ux8xh/eli5_we_see_stories_of_people_who_lose_half_their/
|
{
"a_id": [
"cocibxf",
"cocik86"
],
"score": [
2,
2
],
"text": [
"Uuhh... no. The brain is collosally complex organ that we understand less about then we do about any other part of ... almost anything. It can do a shitton of funky stuff and compensate for TONS of problems. but you might just as wel die as another might survive drom the same injuries. What or where the injury is seems to matter little to nothing. \n\nBasicly the brain is magic and we just dont know fuck about it.",
"It seems possible. \nThe two hemispheres are connected by the corpus callosum which is made of fibers that allow the two sides to communicate. When this is slightly severed, a lot of weird stuff happens. \n(See _URL_0_) \nBy that we can reason that if the corpus callosum was totally severed, there would be a seperate consciousness in each side. If the two hemispheres were seperated after the subject was born, however, there would not be a fully functioning brain on each side. Both sides of the brain become more specialized as we grow. Different areas of the brain eventually control different things, so one side may lack language skills and the other may lack something like facial recognition. \nIf a baby is born with a totally severed corpus callosum and survives, (or if it is severed shortly after birth) I believe that consciousness would most likely arise in both hemispheres, as if each was a seperate brain. I can imagine that there would be limitations, though, because of the smaller size. Also, one side would control the left of the body and the other the right. (right and left sides, respectively.) \n \nPlease keep in mind that this is only based off my personal understanding of this. I am not a scientist or a very smart person. "
]
}
|
[] |
[
"http://www.cnn.com/2009/HEALTH/10/12/woman.brain/index.html?eref=rss_us",
"http://en.wikipedia.org/wiki/Hemispherectomy"
] |
[
[],
[
"http://en.m.wikipedia.org/wiki/Split-brain"
]
] |
|
31kp4d
|
how does the movie 'birdman' look like one continuous take? how did they do it?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/31kp4d/eli5_how_does_the_movie_birdman_look_like_one/
|
{
"a_id": [
"cq2ms49",
"cq2nmqs",
"cq2oral",
"cq2qp9i",
"cq2s6ca",
"cq3357r",
"cq36tln"
],
"score": [
27,
125,
6,
5,
2,
3,
2
],
"text": [
"Whenever there's a scene where there is no characters in the shot and the camera is still.",
"It's easier to see the cuts once you know what you're looking for. Birdman wasn't filmed in one location: the stage and backstage portions, as well as the roof scenes, were on location at the St. James Theatre. Anything in the hallways and dressing rooms was in a different studio. So there's a cut any time a character leaves the dressing room/hallway areas. Same with any time there's a change in time (like the day to night time lapses). \n\nThe cuts that are easiest to see involve a black screen. It happens a lot when characters go up to the rooftop or out of the pub, where there's no light on the door so the screen goes black for a half-second. Another technique they used, going from the dressing rooms to backstage, was having an extra walk in front of the camera. Some of the less obvious ones have cuts when the camera is making a fast pan, like with the drummer while Riggan and Mike are walking outside the theatre. ",
"Like others said, it was done in the same way Rope was.\n\nSide question though, are there any movies that were done in one take? I know the rape scene from irreversible was, but i mean like a whole movie. Probably not.",
"There is a horror movie called Silent House that uses this effect. About 20 minutes into the movie I realized they hadn't made a cut yet, and started looking for it. They just did really long takes and made cuts while the camera pans away from the characters.\n\nSome people don't like the movie, but I felt it was really well done.",
"Actually that one take movie was already done with Russian Ark using a hard drive as a support and a long time before in Hitchcock's Rope... Hitchcock's movie tho was not really a one take as at the time it was technically not possible because of the lenght of the film, so there are actually three cuts when the film was nearly over, with a new take starting from the exact frame where it was stopped (for example on James Stewart's jacket) ",
"Different transitions. There's one where you cut right when the cameras moving quickly, creating a blur. Then you splice in a clip that starts with a blur in the same direction. You can see this in a multitude of films, it's fairly common. There's another where the camera will point up and and then zoom into a light. The light will eventually make one monochromatic color, so the editors can cut and put in a scene thats starts the same way the last one ends. You can see this in many of Gaspar Noe's films. There's an inverse to this transition too. Instead of flooding the frame with light then transitioning, they flood it with heavy movement and relative darkness, making it difficult what's going on screen. Here the editors can cut and go on to a new scene. There's many other tricks but these three are the most prominant.",
"I didn't really understand the film/film ending..anyone care to elaborate?"
]
}
|
[] |
[] |
[
[],
[],
[],
[],
[],
[],
[]
] |
||
1ddc1w
|
What led up to the Tulsa Race Riots and how did it affect Tulsa in the next couple of decades after?
|
Just kinda interested in the Tulsa Race Riots in Oklahoma. I've gone over the basics on Wikipedia, but I was wondering if anyone could give some more in depth details about it, and how it changed Tulsa.
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1ddc1w/what_led_up_to_the_tulsa_race_riots_and_how_did/
|
{
"a_id": [
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"c9pchf7"
],
"score": [
2,
2
],
"text": [
"Howdy fellow Tulsan. Spent a day at Reconciliation Park the other day. I'm sorry that has taken me so long to chime in on, and I will say more later, but I just stumbled across this and I did not want to forget to tell you about it. Are you familiar with This Land Press? If not, I hope you do. [Any who, you might be interested in this.](_URL_0_)",
"One of the precipitating factors of the riot was that the residents of Greenwood, Tulsa's black neighborhood, went armed to the courthouse to prevent the lynching of a young black man who had been accused of assaulting a young white woman. Though lynchings were common at this time, they felt a certain urgency because the previous fall a white man had been taken from the same jail and lynched. One of the local newspapers had written up the story that morning, so it seemed if not inevitable, then very likely.\n\nNationally, the late teens and early twenties saw a great deal of white-instigated violence against black neighborhoods, in response to both the early parts of the Great Migration and the return of black veterans from World War I, who were seen as uppity because they expected the rights they felt were due to them for their military service. Locally, Greenwood was also home to the largest black hotel in the United States, run by a man named J. B. Stradford who was wealthy enough to have lost up to $125,000 (~$1.5 mil today) in the riot. There was a thriving black middle class, and speculations that the riot was also in response to poor whites jealous of black people more well off than they. Purity crusaders also might have lent a hand to the tension, since Tulsa's 'sin district' (as in many cities) was in the black neighborhood, and white men would visit its gin joints and brothels.\n\nAfterwards, part of Greenwood was sold to industrial interests, and the rest rebuilt itself except for a handful of churches. The neighborhood soon became overcrowded and dingy because Tulsa's housing covenants prohibited black people from living outside of that area. What is interesting in terms of long term repercussions, though, is that no one in the city so much as mentioned the riot for decades. All of the documents regarding it had been 'lost' -- the newspaper articles, the police records. The residents of Greenwood were afraid to mention it outside of their own community, and the Tulsa's white population preferred to pretend it had never happened. In the sixties and seventies it gradually began to seep out into public discourse, though the *Tulsa World* newspaper rejected an article about it on the fiftieth anniversary. A new black magazine in the city, *Impact*, published it instead. \n\nIn 1982 the first book on the riot was published by the historian Scott Ellsworth, but even then most of the accounts were oral histories from black Tulsans. The white people he attempted to interview refused to see him once he mentioned his subject. \n\nAll of this was sourced from James Hirsch's *Riot and Remembrance: The Tulsa Race War and Its Legacy*, which I recommend - I'm summarizing, but it explores in depth precisely what you're asking. \n\n(edited a bit for clarity)"
]
}
|
[] |
[] |
[
[
"https://thislandpress.com/store/subs-and-issues/may-1st-2013/"
],
[]
] |
|
wf0jn
|
Regarding acne
|
Why is it that some people get absolutely horrifying acne and other barely suffer from a pimple or two?
|
askscience
|
http://www.reddit.com/r/askscience/comments/wf0jn/regarding_acne/
|
{
"a_id": [
"c5criq3"
],
"score": [
3
],
"text": [
"A big part of acne is related to skin cell turnover- as skin cells die, they break free from their neighbors and fall off. If the bonds that hold them to their neighbors are too strong, they can't break free, they clump up and block pores, trapping bacteria inside. Anti-acne medications like salicylic acid are keratolytics- they break apart keratin, the fibrous material that glues cells to their neighbors, and allow skin cells to shed more easily. Similarly, mild abrasives/exfoliants work to increase cell shedding.\nPeople also have different rates of oil production, and different skin pH, which make for more or less hospitable environments for bacteria (particularly propionibacterium acnes) to thrive."
]
}
|
[] |
[] |
[
[]
] |
|
xhrpy
|
How does a water molecule interact with the glass it touches?
|
I have next to me a glass cup of still water. I am wondering how the molecules of the glass cup interact with the water molecules which are in direct contact with the glass.
Thank you.
|
askscience
|
http://www.reddit.com/r/askscience/comments/xhrpy/how_does_a_water_molecule_interact_with_the_glass/
|
{
"a_id": [
"c5mhfdf"
],
"score": [
3
],
"text": [
"There are a number of different types of glass and the interaction is abit different for each of them.\n\nHowever, for general silica glass, basically the surface is not perfectly smooth. It large imperfections on the scale of perhaps 1 nm for a high quality piece of glass (this can be reduced substantially with higher level processing, though). \n\nThe surface of the glass is generally terminated with Silicon - oxygen dangling bonds. The surface termination is random, and the silicon - oxygen bonding is polar. The oxygen is negativly charged, and the silicon is more positive. The water molecules will therefore be attracted to the surface because they are polar as well.\n\nHowever, that's only half the story. Because in a liquid the water can adopt any conformation, it has a high entropy. For the water to touch the glass it must conform to the shape and charge of the glass (or try to), and therefore it will reduce its entropy. This is why water beads on glass.\n\nIt is possible to make glass hydrophillic, however. By exposing glass to something like an oxygen plasma, the exposed oxygen on the silica surface becomes terminated in OH groups. This gives a stronger charge because hydrogen can't hold onto its electrons as well as silicon can, so the oxygen becomes even more negative and the hydrogen is more positive than the silicon in this situation. This extra energy is enough to overcome the entropy decrease of surface interaction at room temperature, and the water spreads immediately on the glass."
]
}
|
[] |
[] |
[
[]
] |
|
1jxjlq
|
How prevalent were monopolies and cartels in shaping the American economy, ~1940-1990?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/1jxjlq/how_prevalent_were_monopolies_and_cartels_in/
|
{
"a_id": [
"cbjj0wt"
],
"score": [
2
],
"text": [
"This is very difficult question to answer in that the definition of 'cartel' or 'monopoly' is at best flexible. For example, was the telephone company a monopoly? Did the various local telcos of the (rough) time make up a cartel in that they exercised exclusive control over a geographic area and charged very similar prices? Does the fact that the prices were (usually) set by some sort of state regulatory board affect the definition of 'cartel?' \n\nThink also about very large industries, including steel. There were numerous steel manufacturers, but under the basic steel contract, workers were paid essentially the same wages and received essentially the same benefits regardless of where they worked. Factor in the few iron ore producers (mostly in NE Minnesota,) and you have a recipe for a cartel at both ends of the steel production process. Does the fact that the steel producers worked together to create these contracts make them a monopoly? A cartel? Something else?\n\nIf these definitions of 'cartel' or 'monopoly' hold, then it's quite clear that they have had an enormous impact on the US economy -- and that of the world as a whole. "
]
}
|
[] |
[] |
[
[]
] |
||
3m092i
|
How did 'US' forces expect to succeed in the Bay of Pigs invasion
|
25,000 Cuban army,200,000 Cuban Militia, 9,000 armed police against 1500 CIA sponsored counter revolutionaries and 8 B-26 bombers.
I understand that it was a failure, but how and why would the US approve such an attack (damaging their foreign relations) against these odds?
To clarify: This is not a question about US anti communist policy but why would the US engineer such an attack and expect any other result, It seems more like a token effort than any real commitment to overthrowing Cuban communism.
|
AskHistorians
|
https://www.reddit.com/r/AskHistorians/comments/3m092i/how_did_us_forces_expect_to_succeed_in_the_bay_of/
|
{
"a_id": [
"cvb1yfk"
],
"score": [
51
],
"text": [
"Much in the way that Castro had succeeded against similar odds years earlier. The Bay of Pigs was not the original target of the attack, but rather, Trinidad, Cuba, which is on the southern shore roughly in the middle of Cuba. The crucial geographical difference between the two is that the Trinidad Plan allowed for the rebel forces to escape into the Escambray Mountains, which had previously been used to great effect in conducting guerrilla campaigns, while the Bay of Pigs Plan allowed for the air support to be done without air refueling and thus keeping the US footprint lighter. Once the guerrilla fighters planted themselves on Cuban soil and secured a stable area, they were to create a temporary government and petition to the United States for assistance. \n\nPresident Eisenhower originally had the CIA develop the plan and begin training the rebels, but the decision came to Kennedy whether to carry it out. This is where we get to your question - why did the US go through with the attack when the odds were not looking so great? The answer is political. When Kennedy was campaigning against Nixon, he accused Eisenhower of standing by during the Cuban revolution. He could not afford, politically, to scrap this plan, after making that an issue. \n\nThis is where we get into WHY the attack failed, or at least, what didn't help it. Kennedy wanted the footprint light. He and his administration ultimately rejected the Trinidad landing spot and went with the Bay of Pigs, but they also reduced the air sorties from 40 to 8. The Secretary of State, Dean Rusk, and others in the administration and military advisers began to think this was an ill advised plan, especially since Castro was proving to be quite popular. There was no way this invasion would succeed without US support, but Kennedy insisted that US deniability be made the top priority. \n\nIn short: because Kennedy made a choice and his administration and advisers did not voice their opposition to the plan, at least not in a significant manner. \n\n\n\nSource: Combs, Jerald. *The History of American Foreign Policy from 1895*\n\nEdit: I forgot a word in the book title... FOREIGN policy. ooops."
]
}
|
[] |
[] |
[
[]
] |
|
2bizcu
|
the main differences between baptist and pentecostal beliefs
|
Something that lets the outsider distinguish between the two groups.
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/2bizcu/eli5_the_main_differences_between_baptist_and/
|
{
"a_id": [
"cj5u2fl"
],
"score": [
2
],
"text": [
"There are several. Here's three of the big ones, by doctrine: \n\n1. Baptists believe you're saved, then get baptised. Pentacostals believe baptism is a prerequisite for salvation.\n\n2. Pentacostals believe glossolalia (speaking in tongues) is evidence of baptism, while Baptists do not. \n\n3. Baptists believe that once you are saved, you're saved forever, while Pentacostals believe you can fall out of God's grace. "
]
}
|
[] |
[] |
[
[]
] |
|
27i45u
|
During WWII, did the army have units that collected damaged and lost equipment for refurbishment and reuse?
|
I know about the vehicle and armor mechanic units that would tow/drag damaged vehicles back for repair but did they do the same for undamaged helmets, rifles, and other equipment?
|
AskHistorians
|
http://www.reddit.com/r/AskHistorians/comments/27i45u/during_wwii_did_the_army_have_units_that/
|
{
"a_id": [
"ci1dozw"
],
"score": [
2
],
"text": [
"I've also wondered this, also if there was any stigma attached to using captured weapons. "
]
}
|
[] |
[] |
[
[]
] |
|
s62ac
|
How likely is a message in a bottle actually being read by someone?
|
I was (I'm not proud to say) watching the video for Lovefool, and in it, a castaway on an island puts a message in a bottle and sends it out to sea.
My question is two-fold, how far out would you have to get the bottle before currents wouldn't just bring it back into shore, and also what are the odds of it actually getting to land somewhere and being read?
|
askscience
|
http://www.reddit.com/r/askscience/comments/s62ac/how_likely_is_a_message_in_a_bottle_actually/
|
{
"a_id": [
"c4bdiux"
],
"score": [
8
],
"text": [
"In most cases in some traditional small island in a large ocean, currents would wash the bottles away very easily; unless you fling the bottle directly into the incoming tide, it'll just be swept past the island and disappear. Chances are winds or other currents will sweep it far enough away it doesn't hit the island when the tide comes back in.\n\nAs for the odds of it landing somewhere, your best bet for estimating this is to look at the fate of a large fleet of rubber ducks lost into the Pacific in 1992 and subsequently used for the study of ocean currents. Many have washed up over the intervening years, in a number of odd places. _URL_0_ However, the overall recovery rates are still pretty low - just a couple of percent. So you'd want to unleash a lot of messages to have a reasonable chance of somebody finding one. Hope you brought a lot of bottles.\n"
]
}
|
[] |
[] |
[
[
"http://en.wikipedia.org/wiki/Friendly_Floatees"
]
] |
|
g5l2c
|
In vehicles, would it be more efficient to have more or less gears?
|
Like how car's usually have gears from 1-5. Would it be beneficial to have a higher number (i'm guessing this) or lower number of gears?
Let's say if we could somehow create a transmission with an infinite amount of gears and a computer would do the shifting for you, would it be highly efficient?
|
askscience
|
http://www.reddit.com/r/askscience/comments/g5l2c/in_vehicles_would_it_be_more_efficient_to_have/
|
{
"a_id": [
"c1l2gok",
"c1l2ly8",
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"c1l2qrq"
],
"score": [
7,
4,
9,
2
],
"text": [
"The point of gears is to allow the engine to work within a specific range where the engine has optimum efficiency in terms of fuel used vs power generated. Most engines will have a specific \"power range\" which is where the engine will work best. Gears basically allow the engine to stay within this RPM setting as much as possible.\n\nNow, the problem with transmissions is that when switching gears, you lose power to the wheels, and you have to connect the engine to the wheels via a clutch.\n\nInstead of using a computer to shift an infinite amount of gears, why not make a gearbox that actually allows any gear ratio to be used - and before you say *What? Who? How?* take a peep at [this guys take on this exact problem](_URL_0_) which is an infinitely variable transmission - that allows the engine to stay within the powerband CONSTANTLY as well as allowing the car to move forwards, backwards and at any speed without a clutch or the need to engage/disengage gears.",
"CVT? And yes, more is better.",
"I actually just bought a car with a CVT (others have described it here). I can say that thing is stupid efficient!\n\nCruising through the city, the engine never gets above 2000RPM until you hit about 60 mph.\n\nSlamming on the pedal causes the engine to immediately jump to sub-redline RPMs (6400rpm in my case) and launch you with no \"gear hunting\". So much fun and so efficient.\n\nIf I remember right, it's rated at 19 city and 28 highway.",
"Technically yes, but unless you have a CVT, adding gears means adding weight and mechanical complexity. Plus you have to find space to put them in. And each gear helps less than the one before it, so you run into diminishing returns pretty quickly."
]
}
|
[] |
[] |
[
[
"http://www.gizmag.com/steve-durnin-ddrive-d-drive-infinitely-variable-transmission-geared/15088/"
],
[],
[],
[]
] |
|
4hw41b
|
why weed and hops smell almost the same
|
explainlikeimfive
|
https://www.reddit.com/r/explainlikeimfive/comments/4hw41b/eli5why_weed_and_hops_smell_almost_the_same/
|
{
"a_id": [
"d2sthe7",
"d2stkn3"
],
"score": [
4,
2
],
"text": [
"They are extremely closely related, both belonging to the family \"cannabacae\". They share a vast amount of their genetics with cannabis so the smell is similar.",
"They're related plants. It stands to reason they would smell alike. (They also have in common an unusual-in-plants feature of having male and female plants, which makes cultivation more complicated, since in both cases, users want unfertilized female flowers.)"
]
}
|
[] |
[] |
[
[],
[]
] |
||
20ysyt
|
why doesn't my parents' dog recognize my face or voice when i call them on skype?
|
I've been studying overseas for the last year, and when I have made video calls to my parents, they sometimes bring the dog to the computer. Despite me calling her name, she doesn't react in the slightest. My brother's dog doesn't respond to my image or voice either. My parents have pretty good speakers so the sound quality is good. So why doesn't the dog react to me?
|
explainlikeimfive
|
http://www.reddit.com/r/explainlikeimfive/comments/20ysyt/eli5_why_doesnt_my_parents_dog_recognize_my_face/
|
{
"a_id": [
"cg80ldt",
"cg80nbn",
"cg83fzh"
],
"score": [
4,
3,
7
],
"text": [
"He probably does. He just knows you can't scratch his ears via Skype and there's no treats either.",
"Not sure about the lack of voice recognition, but dogs and cats see screens differently than we do. In order for us to detect fluid motion/activity on a screen, there needs to be around 15 frames per second. Think of it like a film reel. There aren't any major differences when you look at adjacent frames, but when they're played through a projector, they string together and we get the \"motion picture\". Dogs and cats require a higher frequency of frames in order to detect fluid motion (around 60ish). So, what we see as fluid movement on a screen is just still shots to them.",
"I have no facts or whatever to back this up, but dogs probably rely on smell a lot in individual identification."
]
}
|
[] |
[] |
[
[],
[],
[]
] |
|
fxo28u
|
How can Animals contract COVID19 but not spread it to us?
|
I read in an article that cats can contract Covid19 from us but they can't spread it to us. Is this true? If yes, I am curious as to how that works, wouldn't the virus be the same?
|
askscience
|
https://www.reddit.com/r/askscience/comments/fxo28u/how_can_animals_contract_covid19_but_not_spread/
|
{
"a_id": [
"fmvu0kb"
],
"score": [
6
],
"text": [
"We don’t know if they can spread it to us yet, but it certainly doesn’t seem to be a major factor.\n\nIt’s not unusual for viruses to be able to infect off-target hosts but not transmit, or transmit very weakly, because the virus doesn’t shed in large quantities. That might be because the virus doesn’t replicate efficiently in the new host (for example, SARS-CoV-2 has been shown to infect dogs, but it’s barely detectable), or the virus may replicate well, but not in a location that lets it transmit (for example, if the virus only replicates deep in the lungs, it may not be exhaled as well as if it replicates in the upper airways). For example, mice can be infected with some strains of influenza, but they never transmit the virus. \n\nThat said, experimentally cats were able to transmit virus between each other. This involved prolonged exposure and didn’t seem efficient, but it’s not impossible ([Susceptibility of ferrets, cats, dogs, and different domestic animals to SARS-coronavirus-2](_URL_0_))."
]
}
|
[] |
[] |
[
[
"https://science.sciencemag.org/content/early/2020/04/07/science.abb7015"
]
] |
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