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3173b4 | why are dogs attracted to whistling? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3173b4/eli5_why_are_dogs_attracted_to_whistling/ | {
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"text": [
"They are not attracted to whistling as much as they are trained, instructionaly or instinctively, to respond to whistling."
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1spf3u | why are works of art like the scream and the mona lisa considered masterpieces? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1spf3u/eli5_why_are_works_of_art_like_the_scream_and_the/ | {
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"If you search on the term \"Mona\" in this sub, you'll find a heck of a lot of answers for that part of your question.\n\nThe cliffnotes version for the Mona Lisa is that it's not *that* technically amazing, it's a fantastically well done piece by one of history's most famous people, but the piece itself only gained such a level of fame after being stolen in 1911 and eventually retrieved. It since became a kind of pop icon, recognisable by the everyman as a representation of high art irrespective of its actual quality. Not that it's not high quality, just that it's not why everyone automatically thinks of it as the greatest piece of artwork ever."
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2cgfcd | how does the cream on a ice cream cake not get frozen? | So I'm eating a Carvel Ice Cream right now and I was wondering......How is it that the whipped cream on the top of the cake stays warm even after being in the freezer while the rest of the cake is still frozen?? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2cgfcd/eli5how_does_the_cream_on_a_ice_cream_cake_not/ | {
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"Well, whipped cream has a lot of air in it. I mean, really, a *lot* of air. Air is a pretty bad conductor of heat. Bad conductor means that it won't change temperatures very easily.",
"Probably because its infused with a lot of air. I know when I was in Iraq they had chocolate that wouldn't melt even though it was 140 degrees outside. The chocolate seemed to be infused with a lot of air. ",
"Fundamental thermodynamics. Very interesting stuff. "
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8oivgf | why do passports expire? | It makes sense for things like a driver's license, where age/vision/etc could impact future driving. Why don't governments just make passports valid for a lifetime? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8oivgf/eli5_why_do_passports_expire/ | {
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"I got my first passport at 17. I am now 49.\n\nIf I showed off that 1986 passport to a border/immigration official, he'd have a hard time reconciling the photo with the guy standing before him.\n\nIf passports expire, however, the photos get updated.",
"1) Prevent identity fraud. It's tougher to use a stolen passport if it has an expiration date.\n\n2) Things age, namely the photo used in the passport.\n\n3) Technology improves. A lot of technology goes into a passport, both for the identification of the holder/authenticity of the passport and to prevent fraud. It's easier to make sure that everyone's passport is updated if you know they're going to expire and a new one will be required.\n\n",
"The most common issue is the photo. Since the passport is meant to be an important means of photo ID, it's important that the photo looks kind of like you. My passport is currently 8 or 9 years old and I still look mostly like I did when I got it, but that may not be true in 10\\-20 more years. So re\\-issuing and taking a new photograph makes for a more accurate ID.\n\nBut the other issue is security. Much like with drivers' licenses, passport fraud does happen. If a passport with no expiration date is stolen and used fraudulently, it could potentially be used forever. But if it has an expiry date, it'll cease to be useful within a few years. Especially since the security features and images in the passports do get updated once in a while. An out\\-of\\-date passport stands out, making it harder to use fraudulently.",
"It is to make sure that you keep the pictures and other information updated. How you look can change dramatically in only a few years. "
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4zdvca | how are people who live paycheck to paycheck able to budget their money so pefectly to end up with zero each week? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4zdvca/eli5_how_are_people_who_live_paycheck_to_paycheck/ | {
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"Honestly when I was paycheck to paycheck I just made sure to stock up food, get a bus pass, and then just spend till it was gone."
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6mhvur | why do many websites make apps for themselves instead of updating their site for mobile users? | I was watching a [video](_URL_0_) by one of my favorite people to read and watch online, and this video (like most of his) made me think. Why do websites make a formatted mobile version of their site and make an app? Using Reddit as an example; how come the app misses features that the mobile browser version has, yet the browser version has features that the mobile app is missing?
Why do sites and companies do this? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6mhvur/eli5_why_do_many_websites_make_apps_for/ | {
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"Apps have the potential to give much more information about you to the company than a website does."
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2idyho | how much louder does a sound have to be to notice it got louder? | Does it depend on frequency? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2idyho/eli5_how_much_louder_does_a_sound_have_to_be_to/ | {
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"Each increase in sound is judged relative to the previous amount of sound. In general, the more sound already present, the more volume has to increase in order for the human perceptual system to notice the change. This generalization isn't always true. See _URL_1_'s entry on the [Weber Fechner Law](_URL_0_) for more info."
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"http://en.wikipedia.org/wiki/Weber%E2%80%93Fechner_law#The_case_of_sound",
"Wikipedia.org"
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2aigi0 | how does wireless communication keep getting faster if radio waves already travel at the speed of light? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2aigi0/eli5_how_does_wireless_communication_keep_getting/ | {
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"Sound generally travels at the same speed, but you can get better at talking faster and understanding faster speech. Same thing, basically. The signal takes the same time to get there but contains more data per second."
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6swvwb | if a nuclear missile is shot down from the sky, say several miles above a large city, what would happen to the city below? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6swvwb/eli5_if_a_nuclear_missile_is_shot_down_from_the/ | {
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"Missile parts would fall from the sky\n\nThere would be no nuclear detonation, they're wayyyy harder to detonate than a normal bomb because if everything doesn't go perfectly you just get a dirty bomb",
"Not much of any interest really.\n\nModern nuclear weapons require a very precise series of timed explosions take place to compress the fissile material and produce a nuclear explosion. An incoming warhead struck by an interceptor missile would not detonate. It would be forcefully torn apart by the impact, and scattered over a relatively wide area in likely very small pieces. The actual amount of nuclear material in a warhead is fairly small, and the resulting contamination would be minimal.\n\nThere would probably be a fairly intense effort to make sure that there wasn't any stray nuclear material or bomb components scattered around the city. However the speeds at which a ballistic missile intercept happens means both the warhead and the interceptor are going to be blasted into very tiny pieces.",
"Similar (but not exactly) events have happened already many times. Read here: _URL_0_\n\n",
"Others have sufficiently answered your question. I'd like to give you some supplemental information. Whole missiles do not travel to their targets in this day and age. Missiles travel into a parabolic flight path into low orbit towards their targets, then detach. Each warhead is contained inside what's called a reentry vehicle, which travel to their targets mostly under the influence of gravity. By the time they reach their target, they are moving at over 5 miles per second.\n\nCurrent nuclear arms treaties limit the number of warheads to 1 per missile. The missiles used by the United States and Russia are able to carry between 8 and 14 warheads, each able to strike a different target. They will also carry a number of penetration aids (decoys) to improve the chances of reaching their intended target."
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d8sapq | why does salt so significantly change the flavor of tomatoes? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d8sapq/eli5_why_does_salt_so_significantly_change_the/ | {
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"Salt does two things, it increases salivation which helps deliver the flavor of tomatoes to your taste buds, and it supresses the bitterness receptors in your mouth, which helps tomatoes taste sweeter than they normally are."
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4ux5mb | even when there are clear blue skies all day, why does night time almost always bring clouds? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4ux5mb/eli5even_when_there_are_clear_blue_skies_all_day/ | {
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"It gets colder at night. Colder air can't hold as much water, and the water cools too, so it condenses into clouds. Clouds are liquid water, not gas. That water is still in the air during the day, it's just invisible vapor."
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1um3sv | so what was b:\ drive? why isn't a:\ drive the primary and how did c:\ become king? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1um3sv/so_what_was_b_drive_why_isnt_a_drive_the_primary/ | {
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"In the early days of personal/home computing, internal hard drives were crazy expensive and not very large. Most programs and data were stored externally on magnetic disks. The drives these floppy disks were labeled A and B, since they were the main source of storage. C was used for the less manually accessed internal drive. As hard drive prices dropped and capacities increased, internal hard disk drives became the main storage. ",
"A:\\ = first floppy disk drive\nB:\\ = second floppy disk drive\nC:\\ = first primary partition of the first physical hard disk\n\nLong time ago in ancient history computers could have both 3.5\" and 5.25\" floppy disk drives before the latter one died out, leaving B:\\ obsolete and now the A:\\ drive is also obsolete when people moved on to CDs.",
"Drives A and B were removable disk drives. In the earlier days, Hard drives weren't always a thing, and even when computers did have them they were small and pretty much everything ran off a disk or needed a disk to start. It made sense that the disk drive started at A, and the second disk drive was B. (Many computers had 2 disk drives, often of different formats)\n\nSo we get left with the next letter, C, being the hard drive. \n\nOn a side note, CD-drives (optical disc drives) were generally given the letter after the HDD to prevent confusing them with a floppy disk drive, thus D and E became common for cd-drives.",
"When the IBM XT (first instance of the PC) came out, it didn't have hard drives. you could add one later, as they became available, but that was later. The A: was the primary drive and you typically got a B: as well. When hdds came in, they took the next slot as standard, just like CDROMs later took the next slot as standard.\n\nBut this is all just convention. It's possible to make different arrangements.",
"Since this question has been answered very well so far I'll mention briefly that on a windows computer you can reassign letters to any of your drives. So if you want an A and B drive again you could rename any drive you have. You have options A through Z.",
"'bout as simple an explanation as you can get: _URL_0_",
"Like many (ancient) people, my first computer had one floppy disk drive - Drive A:. That's all it had to run on. One 5.25 inch floppy drive. Then other people bought these new computers with a second floppy disk, which was the B: drive. Oh, how I envied. \n\n\nAnd then \"internal storage\" came with a newer model. Imagine paying $5000.00 for 10 whole megabytes, but feel the power...of a C: drive. It took YEARS before I got one that was used. It had a problem with overheating, so I had to set it OUTSIDE of the system unit and put a bag of ice on it to keep it cool.\n\nThose were the days...",
"Well, this makes me feel old.",
"This was a DOS standard. Not necessarily MS (Microsoft DOS), but many variations, MS, IBM, Caldera, Novel, Etc.\n\nTypically A: and B: were reserved for the first 2 floppy drives. The type of drive did not matter. Simply the first device on the controller floppy chain was assigned A: the second was assigned B: The cable had a 34 pin straight through connection from controller to drive with a twist in pins 10-16 to differentiate the second drive.\n\nDrives 3: and 4: were common on IBM computers that had a 3rd or 4th floppy drive. These required the use of a second floppy controller.\n\nC: - Z: were commonly used for \"high capacity\" drives. Not necessarily hard drives. These could be hard drives, hard cards, Optical/CDROM, Magneto Optical drives, Syquest, Click, Zip, Bernulie or a variety of other \"large\" storage methods.\n\nOther OS's Unix, BSD, AIX, SYSTEM x, etc during the time did not assign drive \"letters\" they were accessed by their direct hardware path. Allowing for many more than 26 devices to be accessed.",
"Yikes, it's sad that I know the answer to this. I'm getting old.",
"B drive was the second floppy drive.\nit was a big deal.\nIt meant that you could copy disk to disk without floppy swapping.\nFloppy swapping was the nightmare of the 80's but it beat the ever loving hell out of using cassette tapes.",
"Why should C:\\ get to stomp around like a giant while the rest of us try not to get smushed under his BIG FEET?\n\nWhat's so great about C:\\? Hmm? B:\\ is just as smart as C:\\ OK B:\\ is just as cute as C:\\ People totally like B:\\ just as much as they like C:\\\n\nAnd when did it become okay for one drive to be the boss of everybody!? Huh!? Because that's not what PC is about! \n\n**WE SHOULD TOTALLY JUST STAB C:\\**",
"How many of you remember 8\" floppy discs? I only ever saw/used them a couple times very early in my career."
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3kmqxa | why is autotune used excessively in songs these days? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3kmqxa/eli5_why_is_autotune_used_excessively_in_songs/ | {
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"It's practically am instrument of its own at this point.\n\nUsing autotune, you can mask errors in your singing, yes, but you can also get voice effects not possible with natural voices. Many artists thus incorporate it into their style to attain a recognizable sound.",
"Why were synths used so excessively in the 80's? Why were electric guitars used so excessively in the 60's?\n\nWhat it boils down to is that autotune is new technology that is recently become widely available and easy to use. Its in fashion now. It'll fade soon."
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7ivr8d | graphene, graphite, and why one is an amazing super-material and the other is pencil lead and skateboard layers? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7ivr8d/eli5_graphene_graphite_and_why_one_is_an_amazing/ | {
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"*Graphite* is many *graphene* sheets layered on top of eachother.\n\nGraphene is only a single atom thick, and this gives it some odd properties because so many electrons are exposed in identical configurations.\n\nYou can't make a bulk material out of it though, stacking them up allows the electrons in each layer to interact and changes the properties.",
"Because the way atoms and molecules are attracted and bonded to each other in a substance is a HUGE factor in the properties we see in that substance.\n\nGraphite, graphene, diamond, buckyballs, carbon nanotubes are all just carbon atoms in different configurations. Oddly enough those configurations kind of behave how you'd think they behave if they were much larger structures.\n\nGraphite is slippery because it is arranged in flat layers that have strong bonds between atoms in the same layer... but week bonds between layers themselves so they slide around a lot.",
"Graphite and graphene are technically the same thing. Graphite is just broken into lots of tiny pieces.\n\nIt's like a peice of paper ripped into a bunch of pieces then taped back together. The unripped peice of paper is much stronger.\n\nElectrically its the same idea. Its a lot easier for electrons to jump between connected peices than it is to jump to a seprate unconnected peice."
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f1w6so | how do house builders avoid weather damage while the buildings are under construction? | Whenever I see unfinished houses in a downpour all I can think about is all the places water is seeping in to cause damage. How does the potential damage get mitigated by the time a roof and siding gets added? Does the wood really just dry out enough in the sun that it is not an issue? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/f1w6so/eli5_how_do_house_builders_avoid_weather_damage/ | {
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"you build them let it dry out. Dupont Tyvek is special sheet that allows moisture to go one way but not the other.",
"Depends on what phase of construction they are in. In new construction, there is rarely any need to keep things dry during the framing phase. By the time you need to have things kept dry you'll generally see a house-wrap and windows installed as well as a roof (either the final roof, or an underlayment that will stay there for the long run, but is temporarily serving as a water barrier. \n\nThe crudest rule is that if you're gonna put up insulation and sheetrock the house should be dry and be able to stay dry. Anything prior to that and you'd be ok with some moisture as long as it has a chance to dry out.",
"They dry out before things are closed up. They add the exterior wrap and roof while inside is still studs. In worst case, where exposed basement takes on standing water, it'd get pumped out and allowed to dry.",
"It is not as hard as it may seem to prevent weather damage. Proper plans (planning) puts the gross structure in place with a roof. It does not need to be 'water-tight' to prevent damage. \n All you need to do is keep the inside from getting a deluge of water. Also, until covered, you are not installing materials that are very sensitive to water. \n\nThe openness of the construction allows air to go through and dry out most places. You do have to be careful when you are finally closing in the structure in a way that limits air flow, to make sure you have allowed it to dry as much as needed. even after the windows are installed, there is enough exchange of air to help dry things out. It is not until you 'wrap' the outside and put on the roof, that a house becomes water-tight.'"
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12yoya | electromagnetic spectrum | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/12yoya/eli5_electromagnetic_spectrum/ | {
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"I do suppose you should rephrase this to include what exactly it is you want to know: The electromagnetic spectrum is just a range of wavelengths (frequencies) of electromagnetic waves. There really isn't much more to say than that. That said, of course I will say more:\n\nthey are generated (by humans, they come from natural phenomena too, as a result of electrons changing energy levels in various chemical and physical processes) by moving electric charge (or rather, an electric potential) back and forth through a piece of metal, causing the surrounding medium (usually air, but any substance will to some degree) to oscillate. These oscillations are waves of chaning electric and changing magnetic potentials (differences in intensity, like pressure differences) which are called electromagnetic waves. \n\nDepending on the speed with which the potentials change this EM wave will have a frequency. formally there could be infinitely many frequencies and the range of frequencies is 0 (no oscillation but a constant potential) to infinity (no wave*length*, so basically each point has potentials at the same time, like what you get in a square wave at the points where it changes potential). But practically the range 10^0 (=1) and 10^24 (gamma radiation) because Einstein says so. That is, nature decided that energy is not infinite, so there are limitations, just like -273K is the absolute coldest. though there might be some loopholes at microscopic scale, but we aren't really clear on that yet. Either way, you're not going to get electromagnetic waves to move faster as by then they are energy waves: light. And nothing moves faster then light. Except in Quantum mechanics. But let's not go into Quantum mechanics, it is a silly place. \n\nIf you want to use these waves to send information there are more limitations to the frequencies that are usable, as it costs energy to generate them, and there are a lot of complications resulting from interferences, reflections, and losses (basically, when you need to be able to have control over the waveform, it is more difficult to have high frequencies). Which is why mobile phone companies pay good money for a place in the spectrum which they can use to transmit and receive those millions of ones and zeros you demand to allow you look at pictures of cats while you're on the toilet. \n\nso then, what are you looking to hear more about?",
"\n\nJust like gravity, there is a force called the electromagnetic force, which is actually way more powerful. Just like gravity exists when there is mass, the electromagnetic force exists when there are charges. charges can be positive or negative, whereas mass is positive (for most of the part). \n\nWhen charge builds up, it forms the electric field around it. (the field describes how much and to what direction charges will exert force on other charges.) if charges are in motion, it forms a magnetic field. you can cause the magnetic field with moving charge. \n\nif you have a magnet, and you move it near a conductor, it will a cause current flow (which just so happens to be the motion of charge) and the charge will cause an electric field. \n\nThe electric field can indirectly cause a magnetic field, and the magnetic field can indirectly cause an electric field. This happens when the charges stay constant over time. \n\nNow if the charges were to change from positive to negative, the field will begin to move away from the charge. The number of times the charge changes from positive to negative in a second will be the frequency. And when the charges are oscillating, there will a magnetic field WITH the electric field existing at right angles with each other and one does not cause the other. And it so happens that no matter how slow or fast the charges oscillate with time, the field that moves away from the charge as a new charge builds up, will travel like a wave and always at the speed of light.\n\nThe frequency of the oscillation will determine how large the wavelength of the wave will be. this information can be used to make devices that make long distance communication possible, also owing to the speed of the wave.\n\nThe electromagnetic spectrum basically shows the different frequencies of waves and what their wavelengths are, and what they can be used for. "
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bv4uxe | what keeps venomous/poisonous animals from harming themselves? are they born with a genetic antidote? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bv4uxe/eli5_what_keeps_venomouspoisonous_animals_from/ | {
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"Some actually can harm themselves. It depends on the animal. Others are immune to their own toxin, or super resilient to it.",
"Yep. I think for some, they are just resilient. So for example - not venom, but the electric eel - it actually hurts itself a little when it discharges. Additionally snake venom is stored in the glands and venom is only really dangerous in the blood stream. You can't eat venom although I wouldn't do it. Snakes of one type are also \"immune\" to that type of venom. They probably have specialised immune responses for this type of thing. However if a krait bites a rattlesnake then the rattlesnake should get f-worded up. With regards to poisonous animals I had a quick Google search and basically - let's take a receptor associated with muscle movement - the acetycholine receptor. Poison frogs basically use toxins which bind to this. However supposedly their receptors are a little different - so this does not affect them - as the toxin struggle to bind. So essentially it's a combination of resistance and special adaptations. However I strongly urge you to do more research as what I have said is pretty oversimplified.",
"Poisonous animals don't eat themselves, which helps!\n\nand venomous animals don't bite themselves! The venom's usually only an issue in the blood stream, so eating an animal with the venom in (ie you've just killed them) is probably fine because the venomous animal will be evolved to digest it."
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1964qs | why does star wars transcend typical sci-fi fandom and hit home for so many people. | I am a huge Star Wars fan. With all the recent talk about the ongoing storyline, something occurred to me. Not only are my sci-fi buddies excited, but everyone I know is excited. My theory is that despite its sci-fi orgins; the Star Wars series hits home for a lot of people. Why is that? TELL ME. I WANT TO KNOW. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1964qs/eli5_why_does_star_wars_transcend_typical_scifi/ | {
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"Well it was first (sort of).\n\nBefore Star Wars, Scifi in movies was very pulpy and bad.\n\nIt was proof that it could be done well.\n\nIt also has a lot of cultural significance beyond that. Since the success of Star Wars really was the moment when the 'summer blockbuster' aimed at the 15-20 male market became a thing.\n\nAlso it just has a very traditional fantasy arch. Which many people find appealing, especially when looking for an 'escape' in media.",
"I haven't watched SW for a long time now but my mate was talking about this the other day.\n\nHe was saying how it echoed cold war themes of fear, good vs evil, independence and all that sort of stuff. So star wars packed up very contemporary issues and put it in SPACE which was extremely futuristic at that time.\n\nIn this respect I would liken it to the most recent battlestar Galactica (haven't seen the original) series that had invasion and terror as central themes.",
"Star Wars isn't very sci-fi for one. It's closer to fantasy but with lightsabers instead of magic swords and the Force instead of magic.\n\nMore importantly, I think, is that the story is a retelling of the simple \"hero's journey\" tale that people have loved since stories were a thing. It may be a cliche by now to people who are heavily involved in the genre, but it's still attractive as a whole because we all like seeing a regular guy like us rise up and do incredible things.",
"In addition to the reasons listed by other people: Harrison Ford. Seriously, his acting probably made a huge contribution to the popularity of the movies."
]
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30oali | why did fever used to be such a dread and often lead to death? i just rest and drink lots of water, no antibiotics or anything. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/30oali/eli5_why_did_fever_used_to_be_such_a_dread_and/ | {
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"because you couldn't just drink tons of water. fresh, clean, easily accessible water is a fairly new thing. \nplus, most fevers were more than just a fever.",
"Two reasons.\n\n1 - The illnesses we fight today are relatively weak compared to what your grandparents, or even parents might have faced. You are going into with knowledge of what you are fighting and (some level of) vaccines to stop you from getting infected by multiple strong infections at once.\n\n2 - We are a lot healthier. It's much more common for people to have a healthy balanced diet, we (and I say this as someone above the snow line in North America) get a lot more fresh fruit and vegetables than we did 100, or even 50 years ago. This means that we get much more vitamins necessary to maintaining a healthy immune system.\n\nCombine that with generally improved living conditions where you get sick maybe once or twice a year and the fact that 99% of people in the first world have access to clean, potable water, and you have a recipe for fighting infections. Even when you are sick, you have a small, self-contained biosphere where you can often control the temperature, humidity, light level, etc to make it the ideal place for you to get better.\n\nCurrently, you fight off some pretty weak ass viruses. You get colds, you might get a flu bug, if it's really bad you might get pneumonia. But that's because over the past century people cured the worst offenders. We don't have widespread brucellosis (mountain fever), we don't have much yellow fever, smallpox is gone, Spanish flu is gone, etc. These were major issues 100 years ago, which made the other infections worse because they would compound on each other, or you wouldn't be able to rest when you got pneumonia because you had to take care of other sick people.\n\nThis lead to the illnesses not be stopped effectively and suddenly you've got a fever of 102F that doesn't break for a few days. That's the problem, that's why fevers were such a big issue because they were made worse by other conditions and there wasn't much to be done about it."
]
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2ic3w5 | why was the citizens united ruling passed in the first place and what benefits does it provide for the average citizen? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2ic3w5/eli5_why_was_the_citizens_united_ruling_passed_in/ | {
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"For the average citizen, it arguably has negative benefits. \n\nFor big companies, it allows them to give as much money as they want to candidates in an election.\n\nAs for the reason it was made, despite the corruption inherent in the system, and how much power it gives to corporations over people, giving money to a cause is a form of speech, and the 1st amendment says we can't prevent free speech. \n\nWhether you agree with that logic or not, that's what the court decided. ",
"Say you have a court case. It's ruled upon, appealed, and eventually the Supreme Court might agree to look at it. \n\nThe Supreme Court agreed to look at Citizens United because it was an important question that had to do with corporations and unions and how they could or couldn't spend their money advocating for candidates and issues.\n\nThe advantages or disadvantages for the average citizen are debatable. It's a ruling on the rules about campaign/issue spending; what you think about that determines your opinion on the ruling. "
]
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[],
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fkhdjj | why do most online resources seem to be predominantly american? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fkhdjj/eli5_why_do_most_online_resources_seem_to_be/ | {
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"text": [
"America invented the Internet. American companies built the machines that ran the Internet in the early days, and still represent the vast majority of Internet developers.",
"There are about 320 million Americans. Japanese and Russians combined are only about 270 million."
]
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| []
| [
[],
[]
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||
5z4dft | what are operating system or network backdoors? | Also what actually a backdoor is? Like a bug in code? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5z4dft/eli5_what_are_operating_system_or_network/ | {
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"Back door is just alternative access to some part of a program / software / website that's used to facilitate the programmer to edit that part.\n\nRegular users should not have access to it: they should use the \"main door\" to use the website.\n\nIt works like kinda like a backdoor in a shop: clients use the front door and the suppliers and staff use the backdoor to enter the building",
"I like the game analogies, but the fall short on the purpose of network backdoors. There are two kinds of (co-)existing backdoors: the ones installed by developers/publishers (sometimes with the \"encouragement\" of 3-letters agencies) and the ones installed on particular systems by a hacker.\n\nThe first ones are voluntary weaknesses in the code, that lets someone who knows about it circumvent authentication or access controls. Sometimes it's a vulnerability that requires a complex exploit to be used. These ones are hard to find and even harder to tag as \"backdoor\" (developers can, and will, always pretend it's just a regular bug they didn't know about).\n\nThe other kind of backdoor is a service, or a special patch to a running system/application an intruder can install to keep his access, and come back in case the original hole is fixed and passwords changed. This is a reason why it's dangerous to keep a system that was hacked running and not reinstalling it from scratch.",
" > Like a bug in code?\n\nSort of, but it's put there intentionally, and has a specific purpose. \n\nIn most cases the purpose would be to allow them unlock the rest of the system or access data whilst bypassing security measures designed to prevent it. \n\nThat said, a bug that provides access behind some form of security could also be described as a backdoor. \nalso there are instances where malicious external code can create a tunnel through security (from the inside out) to create an artificial backdoor. "
]
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[],
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bgmw5l | what is the point of medications that you need to dissolve under your tongue before swallowing? isn’t it all going to the same place anyway? | I’ve been taking a new brand of melatonin, that says to hold it under your tongue for 30 mins before you swallow it. The previous brand I was using didn’t say to do that, so what’s the difference? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bgmw5l/eli5_what_is_the_point_of_medications_that_you/ | {
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"text": [
"It dissolves faster and passes into your bloodstream by way of the veins under your tongue to take effect faster.",
"Absorbed in to your blood stream via the veins under your tongue versus going through the digestive system and entering the blood stream then. The point is to get the drugs in to your system faster.",
"The vein under your toung is a very direct route into your bloodstream. Dissolving a pill under your toung can have the drug in your blood with in 5 minutes at a level that is therapeutic. Your stomach also provides a buffer because it contains an amount of fluid , the pill dissolves into your stomach fluid and then diffuses into your blood. So its a very slow process in comparison.\n\nCommon drugs that are put under the tongue include Nitroglycerin for Angina , Adivan for anxiety , Suboxone for opiate withdrawal and Melatonin for sleeping. \n\nAll actions that are more effective if they happen fast."
]
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[],
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3tew69 | how do animals like bees, butterflies and eel completely change their physical structure when moving from larva to adult form? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3tew69/eli5how_do_animals_like_bees_butterflies_and_eel/ | {
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"cx5kc17"
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"Ok, once an insect is in a cocoon/chrysalis/whatever, it pretty much *melts*. Well, not completely, but most of it does. Just turns back to goo, or rather into the basic building blocks of an organic entity. But, again, not all of it. Some parts stay solid, and the new insect form rebuilds around that solid part. \n\nAlso, do eels do that? "
]
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| []
| [
[]
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|
||
3prldp | why is there so much air below ice? | I've noticed that when water puddles freeze there is often a very thin layer of ice with an air chamber many times as thick below it. I would expect that ice should be touching water instead. Why do those airbags form? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3prldp/eli5_why_is_there_so_much_air_below_ice/ | {
"a_id": [
"cw8tk8i"
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"score": [
2
],
"text": [
"The water level of the puddle has gone down since the ice formed. Either some soaked into the ground, or it found some channel to drain away through."
]
} | []
| []
| [
[]
]
|
|
43ufvs | the top candidates for the upcoming presidential election. i have no idea who to vote for, because i pretty much disagree with all them on at least one major issue. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/43ufvs/eli5_the_top_candidates_for_the_upcoming/ | {
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"text": [
"The thing is, it's unreasonable to expect 100% agreement with a candidate. If that's what you really want, you'll need to run yourself because no one else will ever agree with you on every issue.\n\nSo you need to set priorities. Decide what's more important and whats less important and decide based on that. \n\nFinally, it's WAAAAY to early to decide your presidential election vote yet. If you don't hold a strong opinion, just skip the primary and vote in the general for whoever you like best. It's not about a perfect match. ",
"Welcome to life.\n\nThe only way you'll ever have a candidate you agree with on every major issue is if you run yourself."
]
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[],
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43esqw | can someone explain the whole finebros controversy? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/43esqw/eli5can_someone_explain_the_whole_finebros/ | {
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"They did something that was unoriginal but funny. \n\nGot a following and then told the government they own the format and title kids react to \"xyz\". \n\nThe government said sure. Other people were doing the same unoriginal but funny idea, like Ellen then they got butt hurt and sent their lawyers to politely threaten them if they don't stop. \n\nReddit found out and now the Internet is pissed. "
]
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[]
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|
||
1jkcsd | why coffee shop coffee tastes so much better | Why is it that the coffee that's sitting in the dispenser for hours at the downtown coffee shop tastes like the nectar of the gods, and my fresh brewed (machine) coffee tastes like bitter burnt ass water? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1jkcsd/eli5_why_coffee_shop_coffee_tastes_so_much_better/ | {
"a_id": [
"cbfi7l1",
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"text": [
"It's the coffee beans. Coffee shops buy higher quality whole beans than you are likely to purchase yourself (although purchasing quality whole beans is an option, they just cost more and should be handled differently).",
"Depends on the equipment. Remember your making something at home, just like if it was beer, wine or cake the tools and ingredients matter. The hard and fast rules for better coffee is, good beans, grind each time you use them, use water with a low mineral content read one or two articles on extraction and enjoy. Awesome but easy equipment list (obviously this is with no knowledge of your budget:\nBonavita Coffee Maker\n_URL_0_\n\nGrinder\n_URL_1_\n\nI do believe manual is better but that is another can of worms."
]
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| []
| [
[],
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"http://www.bonavita.ca/bonavita_8_cup_coffee_maker_glass.htm",
"http://www.amazon.com/Baratza-Virtuoso-Conical-Coffee-Grinder/dp/B000FLWCOG"
]
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|
ch69sn | why does english have so many strange and varied collective nouns for animals? | It just seems like itd make more sense to have one simple word for all or at least a handful. School for fish. Flock for all birds. Herd for mammals? But no a group of cheetahs is called a coalition? A group of ferrets is a business? These just seem like jokes and considering most of us have never used or heard of them they seem pointless. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ch69sn/eli5_why_does_english_have_so_many_strange_and/ | {
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" > These just seem like jokes \n\nPretty much, yes. [Terms of venery](_URL_0_) are essentially an in-joke from the 1400s that happened to get written down. Some modern English speakers like them, most don't know about them.",
"There is no real point to it, it is as much a celebration of the sheer variety of the English language as anything else.",
"If you don't know the fancy word for \"a group of something\", you just say group. You can say \"I saw a flock of birds\" or you can say \"I saw a group of birds flying around\" or \"I saw a bunch of birds\" or \"I saw a lot of birds\" or \"I saw a shitload of birds\" or \"I saw a few birds\". All can be accurate, depending on how many birds there are and what they're up to. \n\nIt's interesting, because just saying \"I saw a group/flock of birds\" typically means the birds are all of the same species and have some kind of social connection. Whereas \"I saw a lot/couple of birds\" could mean you went to the zoo or the beach or the woods and saw several different types of unrelated birds, like a flamingo and a pigeon and a penguin and an eagle."
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| []
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"https://en.wikipedia.org/wiki/Collective_noun#Terms_of_venery"
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5suh9p | analog to digital converter | ELI5: How is an analog to digital converter work?
Am I wrong in assuming the output as a digital bit i.e. 1 or 0?
Can you cite an example? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5suh9p/eli5_analog_to_digital_converter/ | {
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"Input: a continuous signal, like a voltage\n\nOutput: a binary number that indicates the measurement of the voltage. Usually a number of bits, like 8 bits or 32 bits.\n\nA tape measure is a simple example of an analog to digital converter (a physical one). You give it a physical distance, and it tells you the closest numerical measurement of that distance.",
"The simplest analog-to-digital converter is a switch. In one position, the switch is 'off', and in the other it's 'on'. That would either send out a 0 or a 1 respectively.\n\nThe next step up in complexity would be something like a thermometer. At the lowest temperature it can sense, it would send out a series of '0's (I'm as cold as I can get). At the highest, it would send out a series of '1's (I'm as hot as I can get). In between, the number simply represents how high up the scale the temperature is in a digital form.\n\nA more complicated analog-to-digital converter is a USB microphone. The magnet in the microphone would take the sound waves it gets and convert that wave into a digital number that changes over time. Based on how that number changes, the computer can 'rebuild' the wave in its memory and play it back as a digital sound. The higher quality the digital output (the more 1's and 0's it uses), the more accurate the sound.",
"The nuts and bolts of how its done is called an [R 2R ladder.](_URL_0_) \n\nAn electrical engineer would know more than me. But I took a few EE classes and actually got to make one of these. The basic concept is that you create a scenario where the more voltage is applied to the input the more output bits become active. \n\nThere is always a water analogy with electricity so for this you can think of a graduated cylinder with holes drilled in the sides going up the height of the tube. Lets say there are 8 holes(8bit) and you filled the cyclinder up half way with water then we should see water coming out of 4 holes (1's) and 4 holes with no water (0's). If the cylinder was full you would have water coming out of all the holes. \n\nYou can change the accuracy of the DAC by decreasing the space between the holes(changing the resistor values). You can also change the resolution by increasing the amount of holes(adding more resistors to the ladder).\n\n",
"Some implementations of Analog-to-Digital Converters (ADC) use a \"Keep guessing until the numbers match\" algorithm and often use a Digital-to-Analog converters to work. \n\nWhen working with microprocessors you often need to wait for your analog to digital conversion process to be finished as it takes a number of clock cycles for it to work out the value. \n\n[Here's an example circuit of what it could look like.](_URL_0_) \n\nYou start with an input voltage that is compared against a reference voltage by an operational amplifier. (it basically is a comparator) \n\nif the voltage on the + side is larger than the voltage on the - side the out put voltage will be high (think of it as a binary 1). \n\nyou then feed this 1 to an Adding circuit. now we are in the digital world. \n\nThe adding circuit has a \"clock\" signal put in it. Its a square wave. All this does is control when the the adder should add the inputs together and push it out. The clock will only do this on the high part of the square wave. \n\nThe adder outputs a digital value (8 wires one for each bit), they are notated bundled together as a \"bus\" of 8 wires. \n\nNotice that the output of the adder is fed back to the input to the adder. What this means is that every time the clock actives an addition operation it adds the value of its last clock cycle with the output of the input comparator. This basically means it's counting upward. \n\nFollowing the output of the adder downward you'll see a series of resistors put together into another Operational Amplifier used in a completely different mode. This type of circuit is called a [Summing Amplifier](_URL_1_) and itself is a **Digital-to-Analog** Converter. \n\n\nThe output of this circuit is fed back into itself as a form of feedback. As long as the feedback value is lower than the input value the comparator will be high voltage and the adder will see that as a 1 and keep adding one to the value. \n\nOnce the feedback path is higher than the input path (meaning its close enough to the reference) the comparator will go to a low state (or binary 0). The adder circuit will just be adding 0 to the computed value. This can be passed into additional electronics and with the output of the added to tell other components that the Analog to Digital conversion is complete. \n\n\n\n\n",
"Computer engineer here.\n\nADCs and DACs are extremely common parts of modern electronics.\n\nThere are a variety of designs for each but that's a bit beyond the scope of ELI5 so I'll leave that bit up to you should you choose to do so.\n\nAn ADC takes as an input three *continuous* values:\n\n1. A minimum voltage\n\n2. A maximum voltage\n\n3. An input voltage\n\nThe minimum and maximum voltage are used to calibrate the range of output values. A very common minimum voltage is 0 volts, and a very common maximum voltage is 5 volts.\n\nAn ADC produces one *discrete* output value in digital form which is an arbitrary number of bits in length. The greater the number of bits, the greater the precision of the device; the more precise the device is, the less information is lost.\n\nConsider a rather simple linear 2-bit ADC with an input voltage range of 0v-5v. Since this ADC outputs two bits, there are four possible binary outputs: 00,01,10,11. In base 10 these are just 0,1,2,3.\n\nSince this ADC is linear, each output symbol is linearly spaced across the range of input values. A 5 volt range divided by four possible outputs yields a precision of 1.25 volts. Non-linear ADCs/DACs are useful when greater precision is necessary only in a certain range; a good example is a telephone conversation, telephonic ADCs/DACs are non-linear as they are designed to capture speaking amplitude.\n\nAn input in the range of [-inf,1.25) volts will result in an output of 00.\n\nAn input in the range of [1.25,2.5) volts will result in an output of 01.\n\nAn input in the range of [2.5,3.75) volts will result in an output of 10.\n\nAn input in the range of [3.75,inf] volts will result in an output of 11.\n\nNote that good circuit design should never permit the input voltage to fall below the minimum set point or rise above the maximum set point. How each ADC responds to this is defined by each manufacturer.\n\nWhereas our 2-bit ADC has only four possible outputs for an infinite number of inputs, an 8-bit ADC has 256 possible outputs for an infinite number of inputs, and a 16 bit ADC has 65,536 possible outputs for an infinite number of inputs.\n\nWith that said, more precise ADCs are more costly, are larger, are slower, and are subject to electromagnetic and thermal noise.\n\nDACs simply reverse the process."
]
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| [
[],
[],
[
"https://en.wikipedia.org/wiki/Resistor_ladder"
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[
"http://i.imgur.com/ymd74sx.jpg",
"https://en.wikipedia.org/wiki/Operational_amplifier_applications#Summing_amplifier"
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|
35cyah | dr. oz's credibility (or lack thereof) | I hear a lot about Dr. Oz being illegitimate and spreading false information. Conversely, I know people who act as if everything that comes out of his mouth is a universal truth. Can someone explain, using true facts and information from an unbiased perspective, how credible Dr. Oz really is? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/35cyah/eli5_dr_ozs_credibility_or_lack_thereof/ | {
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"He has been paid by multiple supplement companies to restate their unsubstantiated claims. It's a disgrace. Last week tonight did a fantastic episode and follow up on it. Please have those you know that take the shit he spews as gospel to watch these... There's a reason why so many of his colleagues want him removed from the position at Columbia. \n\n Last Week Tonight with John Oliver: Dr. Oz and Nu…: _URL_0_\n\nAnd \n\nJohn Oliver - Dr. Oz: _URL_1_\n",
"-He advocates homeopathy, which if you don't know is a way to treat diseases by giving a small amount of a drug that would cause the same symptoms as the disease the person already has if administered in larger quantities. Homeopathy has absolutely ZERO biological plausibility and rarely ever works. Steve Jobs had a very rare type of cancer that is almost always curable but he decided to go the homeopathic route.\n\n -Segments of his show are a about weight loss drugs/methods that will later show up in commercials in the same episode, leading people (rightfully so) to believe that he directly advertises for the companies that make the weight loss pills.\n\n-A study done by British Medical Journal concluded that 51% either had no scientific evidence or flat out contradicted what we know about biology _URL_0_ ",
"Using true facts, as requested:\nDr Oz is a real doctor, a damn good one: \n\"Over the course of his career, he has performed 5,000 open-heart surgeries\"\n\n\"Oz graduated from Harvard before moving over to the University of Pennsylvania, because they have the best business school in the world and he wanted to earn an MBA while going to medical school, in case the whole \"being the world's best heart surgeon\" thing didn't work out. \"\n\nThose are some damn good credentials, then whenever you give someone a show, their credibility raises 1000%, e.g., if it wasn't for his show, Rush Limbaugh would be less credible than a hobo in the park.\n\nNow, he's not doing a show for his love of people, he's doing it for the money, and he's been advertising some supplements that are no better than snake oil, like homeophaty and weight loss supplements that the scientific community agrees are completely useless.\n\nProblem, if you pit a TV celebrity against hundreds of unknown scientists and real facts, a lot of people will side with the TV celebrity (check Jenny McCarthy and the vaccination crisis). You sometimes can't battle real science against a bunch of people on TV spewing crap."
]
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[
"https://youtu.be/WA0wKeokWUU",
"https://youtu.be/TucUMpWWe8A"
],
[
"http://www.washingtonpost.com/news/morning-mix/wp/2014/12/19/half-of-dr-ozs-medical-advice-is-baseless-or-wrong-study-says/"
],
[]
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|
|
201k3r | why do politicians support charter schools? do they not have faith in public schools? | Charter schools are tax payer funded schools that make a profit and have a strong lobby. I see they are supported by republicans and democrats like Gov. Cuomo in NY, which was totally surprising to me. I think it is a waste of tax payer money to give to private/public ventures. Is there something I'm missing? Why are charter schools getting support from our public officials? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/201k3r/eli5_why_do_politicians_support_charter_schools/ | {
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"There are charter schools, then there are charter schools. As a parent, I chose a charter school for my son because of their charter - they are run as a non-profit, by a council made of parents elected by their peers. We get some funding from the County, but we also volunteer, do fundraising, apply for and get grants from public and private sectors.\n\nTo me, a charter school is a school where I get to participate more and be an integral part of my child's education. I know the teachers by name, my wife and I volunteer in class and we know the names of the students and the class dynamics. We know what's going on and we have a say in it.\n\nCharter schools are subject to fewer rules and receives less money from the government than public schools. These are the principles behind a charter school, as envisioned by the person who thought about them first, Ray Budde, in 1974. The fact that Budde was president of the American Federation of Teachers, a powerful teacher union, is interesting.\n\nFor decades, they have been done as schools of choice, with a bit more flexibility than public schools could afford. Since Bush and No Child Left Behind, however, the idea has been embraced by Republicans as a way to defund the public school system and weaken teacher unions.\n\nSo it is true that both Democrats and Republicans support charter schools - but for opposing reasons and they really support different, and incompatible, types of charter schools."
]
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| []
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[]
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|
|
2eqzfh | what happens when a car engine is "broken in"? do engines even get broken in? | Some say they are faster, get better fuel economy, etc. Then there are two apparent break-in periods. 1 being the factory 3500 mile (give or take) break it, and then the one that owners supposedly get way down the line. Are either of these real things? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2eqzfh/eli5what_happens_when_a_car_engine_is_broken_in/ | {
"a_id": [
"ck235x3"
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"score": [
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"text": [
"Metal parts that contact each other have tiny manufacturing defects, stich as burrs. When they are assembled into an engine and the engine runs, they rub against each other. Over time, some of the defects are worn away and the parts move against each other better. "
]
} | []
| []
| [
[]
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|
|
3ibci1 | why can't noise-cancellation be achieved with an app | There are many notable noise-canceling headphones that achieve this with hardware. Why isn't there an app that does that with the existing hardware of the smartphone? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3ibci1/eli5_why_cant_noisecancellation_be_achieved_with/ | {
"a_id": [
"cuewtir"
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"score": [
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"text": [
"Active noise cancellation headphones rely on small microphones on the earcups of the headphones to work out what noise they're trying to cancel out. If you're relying on the microphone on a phone headset, or even the one on the handset itself, you'll get a different sort of noise to what's actually reaching the ears and won't be able to cancel it as effectively."
]
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| []
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[]
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|
|
9hsgrt | how do surgeons remember every little step for every surgery they may need to perform? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9hsgrt/eli5_how_do_surgeons_remember_every_little_step/ | {
"a_id": [
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"text": [
"They usually specialize in just a few operations, and yes there are checklists. For more complicated operations there may be people assigned specifically to the logistics of tools and staff coming and going from the operating table.\n\nSometimes they'll walk the whole surgical staff through a mockup of the surgery beforehand if it's something lengthy, complicated, or dangerous.",
"It’s interesting that you mention checklists. Because Dr. Atul Gawande, a surgeon, wrote a book, *The Checklist Manifesto*, extolling the importance of checklists for *everyone*, he provides examples of how surgeons do mess up when they don’t use checklists—that everyone is more error-prone when they don’t use checklists.\nAnd he gives an example of a famous plane crash that happened due missing a step, which had led to the required use of checklists."
]
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[],
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39uxnt | what's that feeling in your testicles when you drive quickly over an incline in the road? | You know what I'm talking about. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/39uxnt/eli5_whats_that_feeling_in_your_testicles_when/ | {
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"I'm not sure about testicles, but usually it's a feel in the stomach area. \n\nYou're in a small free fall so your organs (and the liquid in them) are moving about without the gravity to keep them pinned down like they normally are. . The nerves around are all \"wtf\" and shoot off some messages. Your body stays put because of the belt, but the organs have some room to move around. \n\nThen gravity kicks back in eventually and it goes back to the way it was before, ending the sensation. ",
"Your body senses that you are falling, and as such your muscles tense to protect vital areas. Your body considers the genitals to be vital, and as such it reflexively protects them.\n\nAs to why it feels weird, that is due to the relatively low amount you use those muscles."
]
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[],
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fyn71q | why does someone’s pulse randomly get very strong on random parts of the body? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fyn71q/eli5_why_does_someones_pulse_randomly_get_very/ | {
"a_id": [
"fn0u6xi"
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"score": [
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"text": [
"Those places are where an artery is sufficiently close to the surface and/or is sufficiently large, to have a pulse strong enough to detect by touch."
]
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||
1bvsuv | that feeling you get in the pit of your stomach that something has gone wrong or is going to | Pretty simple, that feeling you get that something has gone wrong somewhere or is going to go wrong, I've only had this feeling a few times and last time I had it I broke my collarbone. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1bvsuv/eli5_that_feeling_you_get_in_the_pit_of_your/ | {
"a_id": [
"c9aja78"
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"score": [
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"text": [
"This is called \"confirmation bias\". Our brains are very complex pattern-recognition machines. Often we associate unrelated events to real world results, like a lucky jersey causing our favored team to win. In this case you felt uneasy and then something bad happened, and your brain is associating them without plausible reason. You are forgetting about all the other times you were uneasy and nothing happened at all."
]
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[]
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56qold | why does every single company make you sign up with a credit card for a free trial? | Deters me more than making me want to sign up more.. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/56qold/eli5_why_does_every_single_company_make_you_sign/ | {
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"text": [
"Most times the free \"trial\" is actually a subscription where the first month is free, and you're automatically billed afterwards if you don't cancel before then.\n\nIt's shady as hell.",
"It's basically because, once the free trial has expired more people tend to keep the service instead of going out of their way to cancel it, and that way they already have the billing information to charge.",
"In addition to trying to make it easier to get people on a subscription plan, by making people sign up with a credit card they stop people from using their service purely through free trials. They wouldn't have much of a business model of you could just sign up every month with a new account for free service.\n\nBy requiring a valid credit card they avoid giving out endless free service.",
"In addition to the answers given by /u/aboxfullofdoom and /u/Phage0070, it can help to stop abuse.\n\nIf you have to enter your credit card number to make an account, you'll think twice before signing everyone in your street up to the dildo of the month club.\n\nIt's also helps to increase the quality of signups. If something is free and easy to get a lot of people will sign up for the hell of it, even for something they're barely interested in. If you have to give them payment information and remember to cancel, you'll think twice unless it's something you'd seriously consider subscribing to anyway."
]
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u5rvo | baseball stats | Reddit, I'm fairly "sports literate" for a girl but I did not grow up with baseball. Living in Phoenix I developed a love for the game by going to spring training games every year but only recently have I started paying attention during the regular season.
I understand the basics of how the game is played, how runs & outs work, but I don't understand all the stats that come along with the game! I have read through a few other posts in ELI5 about the basics of the game but most of the explanations there are things I already know. I've also tried reading up on _URL_0_ but I've found there's way more I don't know than I do.
Any sort of elementary explanation for the main stats I should be aware of as a team and as individual players would be super helpful! Just enough to be able to understand when they do the highlights on players & teams at games/ during score center type discussions. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/u5rvo/eli5_baseball_stats/ | {
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"I'm more than willing to help but I really think it would be more efficient for both of us if you named things you didn't know and I explained them to you. It helps no one if I explain in detail something you already know.\n\nAs a brief outline stats are generally divided into four categories.\n\n* Hitting\n* Defense\n* Base running\n* Pitching\n\nHitting is basically batting percentage, on base percentage, and runs batted in (RBIs - sometimes pronounced as ribbies as a joke).\n\nDefense is basically number of errors committed by a player.\n\nBase running is basically how many steals and the stealing percentage.\n\nPitching is basically type of pitches the pitcher knows and \"earned runs against\" ERA. Plus about a million more.\n",
"Baseball geeks, forgive me, I'm oversimplifying here... The best thing to know is what the statistical abbreviations stand for, and how they relate to each other. AB is 'at-bats', it's the number of times the player has come to the plate, and therefore the number of chances the player has had to get a hit this season. H is 'hits', and it's the number of hits the player has gotten this season. AVG, or BA (same thing) is their 'batting average', and they figure it out by taking 'at-bats' divided by 'hits' to give you a percentage. A player with 100 at bats and 25 hits = BA .250. So a player hitting .250 is getting a hit 25 percent of the time they come up to bat. Something to be aware of as a newbie is that a batting average of .200 or lower is generally not good, and .300 or higher is very good. As with all statistics, sample size matters, so keep in mind the number of AB when looking at their batting average. Batting average is the most commonly cited offensive statistic. 2B,3B,HR means the number of doubles, triples, home runs the player has hit. K is the number of times they've struck out, and BB is the number of times they've walked. Don't worry too much about SLG and OPS if you're new to baseball. You'll get there eventually.\n\nThe basic pitching statistic is ERA, or Earned Run Average. It's sort of complicated, but boiled down, it's about the average amount of runs a pitcher gives up per nine innings of work. So a smaller number is better. Generally speaking, pitchers with ERA's of below 3 are very very good and pitchers with ERA's of 5 or more are not so good. \n\nThere's a ton more I could write, but Batting Average on the offensive side and ERA on the pitching side are the two key stats to understand if you're interested in how good or bad a year your team's players are having."
]
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"MLB.com"
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[],
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bw99hh | what is the reasoning behind us getting excited when meeting celebrities, asking them for photos, signatures, and such? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bw99hh/eli5_what_is_the_reasoning_behind_us_getting/ | {
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"text": [
"For the same reason that a person may get excited if they see a super rare car, or rare animal, or an astronomical phenomena that only occurs every 100 years. It is an unusual occurrence that may only happen a couple of times within your life time.\n\n & #x200B;\n\nAs for interacting with the celebrity, the same applies, but anxiety will amplify the feeling."
]
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64og67 | how does an antibiotic know how to destroy infections in random places in the body? | How does the antibiotic even find the infection and does it just flat out kill infection? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/64og67/eli5how_does_an_antibiotic_know_how_to_destroy/ | {
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"It affects your whole body. Some people suffer adverse affects after taking antibiotics because they can throw off your entire system. We've got plenty of organisms in our bodies that are good for us. Sometimes, they get caught in the crossfire.",
"It doesn't. Antibiotics are like Alcohol. Once applied, it affects whatever it touches and has no bearing on where it goes. Antibiotics are distributed throughout your entire body from pills. \n\nYou can get site injections that help target antibiotics, but even at that point the antibiotics get absorbed into the bloodstream and wind up all over your body after a period of time.",
"Great question! Some other posters are right. The antibiotic goes wherever the body sends it. The antibiotic is designed to be more toxic to the bacteria because it is designed to attack parts of the bacteria that ideally our cells do not have. Bacterial cells have some important parts that our cells do not. The things called enzymes that make these parts are what the antibiotics normally work against. \n\nWe also can design drugs that behave differently in our bodies to make them more useful. By making changes to the chemical structures we can make them absorb better in our stomachs so they get in our bodies faster, or make them slower to leave our blood. If you have a urinary tract infection, a drug that gets in your urine fast is great. If you have a bad case of food poisoning, a drug that stays in the gut rather than being absorbed in your stomach is a better option. So knowing where you are sick and what is causing your illness all are factors in deciding which antibiotics to prescribe. ",
"Antibiotics, like most medication, is not able to target a specific area in the body. It travels throughout the body through the bloodstream reacting with ALL susceptible organisms it meets. This is why it is recommended you take a probiotic and/or eat yoghurt with live cultures while taking an antibiotic to help restore some of the natural organisms found in your body (digestive system in particular). \n\nAntibiotics are either broad-spectrum (kills everything) or specific to certain sub-groups of bacteria. ",
"The key here is that antibiotics are not really bacteria specific. You have many kinds of bacteria in your gut, so you can get adverse effects from using antibiotics. All bacteria are NOT killed by antibiotics, they're resistant to them. They have genes called beta lactamases that are able to cleave antibiotics with the beta lactam group. ",
"Antibiotics don't \"know\" where to go and how to get to the infection. However, different antibiotics distribute within the body differently and on different time scales - what we call \"pharmacokinetics/pharmacodynamics,\" or \"PK/PD\" for short. Also, different antibiotics affect different pathogens differently (their \"spectrum of activity\").\n\nSo, your doctor prescribes the correct antibiotic (and formulation) for your specific infection, considering both the underlying bacterial strain(s) and the location of the infection. \n\nFor example, vancomycin is an antibiotic that is not absorbed well when taken orally - that is, it does not cross over from your stomach to your bloodstream, what we call \"oral bioavailability.\" So, for specific types of gastrointestinal infections (such as those from Clostridium difficile) where you would want to keep a high concentration of the drug in the gut, it's a logical choice. \n\nBut, for an infection elsewhere (such as an abscess in the skin), it would be a terrible choice, as not enough antibiotic would get to the site of infection from the gut. Thus, you would need to use an intravenous formulation of the same drug (or choose another antibiotic that is orally bioavailable).\n\nSource: I work for an organization that works on antibiotic development"
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56bh0r | what defines a different species ? | For example, there's like 350,000+ species of beetles, but I'm pretty sure it's impossible for all of them to look different to one another. So there are lots of beetles that are considered different species but look exactly the same to the naked eye.
I've also read that species are considered different when they can't produce viable offspring together, but is that true ? That 2 almost exactly the same beetles, different species, cannot reproduce together ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/56bh0r/eli5_what_defines_a_different_species/ | {
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"This is actually a very [hard question](_URL_0_) because the real answer is that nature doesn't provide a hard, definitive line. Life exists on a rather continuous spectrum and any lines we draw between \"species\" are just ones humans have made up to make sense of the world around us.\n\nYeah, we can look at a cow and a tree and say that these are different species of living organisms but when you really start looking in the weeds things get a bit murky. As an analogy, we can see that red and orange are different colors but when you start looking at the spectrum of light it becomes a bit difficult to say *exactly* where red ends and orange begins. We can arbitrarily set a line, but that is just an artificial label we have created for our own purposes.\n\nSo the short (and rather unsatisfactory answer) is that different species are what we say they are. In practice scientists look at a lot of different factors, but no single factor is set in stone. While sexual reproduction is a very big factor it doesn't always apply.\n\nFor example:\n\n* Mules cannot interbreed (all known male Mules have been infertile). So there is no sexual reproduction, yet they are all the same \"species.\"\n\n* Buffalo and cows are not only different species, but belong to different genera but can nevertheless mate and produce offspring (Beefalo) but those offspring are also fertile!"
]
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[
"https://en.wikipedia.org/wiki/Species_problem"
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6hoopj | why some videogames take a long time to install but other games can be put in and played instantly | For example the wii plays games without any installation but games on the Xbox and PlayStation take time to install | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6hoopj/eli5_why_some_videogames_take_a_long_time_to/ | {
"a_id": [
"dizxbnf"
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"text": [
"If it has to install, that means it's putting at least some (but usually most, I think?) of the game files on the consoles hard drive and then running the game off that. The game doesn't need the disc to play after that but makes you insert it anyway as a form of simple DRM. If it doesn't install, it's running the game off the disc.\n\nRunning off the hard drive is faster because computers can read hard drives way faster than they can read discs. This is even more important now that console games often get downloadable updates. Changing files on the drive is much easier and runs faster than loading up the unpatched files from the disc (which are read-only) and then changing them while the game running.\n\nThis is also why fast drives (such as SSDs) give shorter load times; it takes less time to get all the information needed for the next part of the game."
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20bvr9 | construction workers of reddit, what is that tripod thing i see you guys using every other day for hours on end on roads and construction sites? | A few Google searches and I *think* its called an electric theodolite? Sure looks like that! | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/20bvr9/eli5_construction_workers_of_reddit_what_is_that/ | {
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"There are many tools that have been used historically. The people using them are called surveyors.\n\nThere's one called a level that can be used to find the elevation of terrain. There's a theodolite that is used to measure vertical and horizontal angles between sighted points.\n\nBut mainly today they use advanced machines called total stations. They compute distances, angles, and elevations based on where the station is planted.\n\nHow do they know the elevation and other relevant data of the point where the total station is placed? There are certain fixed and protected points called \"benchmarks\" that are constantly monitored and whose positions and elevations are kept up to date using GPS. From a known benchmark every other point of interest can be located precisely using a total station and the mathematics of surveying (which involves a lot of trigonometry and geometry)."
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7bmyh9 | why do we celebrate someone’s birthday? why do we celebrate the day someone was born? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7bmyh9/eli5_why_do_we_celebrate_someones_birthday_why_do/ | {
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"Essentially, when we celebrate a birthday, we're saying, \"we really value you as a person, so much in fact, that we've decided to hold a celebration honoring the day you were born.\" It's also nice to make someone feel special every now and then; why not on a day that has some meaning?"
]
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4wn5az | why is it that humans have no knowledge of reproduction at birth, while most animals have it hardwired into their genetics? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4wn5az/eli5_why_is_it_that_humans_have_no_knowledge_of/ | {
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"Humans also have it hard wired into their genetics. The programming just doesn't seem to turn on until puberty.\n\nEmphasis on \"seem\" because most prepubescents would have curiosity about reproduction, but society trains them to keep it hidden until they're older.",
"Having \"knowledge of\" something is different than having it hardwired. Even if a given human never learns about reproduction, they still have it hardwired. ",
"I'm not aware of any other animals that show an interest in reproduction at birth. That usually comes when they start to approach sexual maturity, just like humans. Humans just take longer to mature than most animals.",
"Maturity rate of a human is 12-16 years before able to reproduce. Other animals is much much faster, a matter of weeks/months for some rodents.\n",
"It is hardwired in humans too. Those things do not \"turn on\" until after puberty or the equivalent for the species. This is true for rats as well as dogs and everything else. ",
"I guarantee if you drop off two 14 year old kids in a forest with no prior sex ed, and come back in 10 years, they'll have plenty of offspring.",
"Humans have it hardwired into their genetics as well. There seems to be a common misconception that animals instinctively know how to reproduce but humans have to be taught. It's been a long time since my sex ed class, but I'm pretty sure it mostly focused on how NOT to reproduce. Leave teenagers alone long enough and they will reproduce. And like animals, they will have no idea what caused it. In fact, that was the joke going around school at the time. Every time somebody got pregnant or had a baby, some clever bloke would say \"I've heard they know what causes that now.\"\n\nYour average dog, for example, doesn't know \"if I want puppies, I have to do these certain acts at a certain time.\" They don't decide they want puppies and do these acts in an effort to cause them. Instead, they instinctively do these certain acts sometimes. Later, puppies come about. They have no idea that the actions they did some weeks/months before caused the puppies.\n\nLikewise, your average teenager doesn't know \"if I want babies, I have to do these certain acts at a certain time.\" But they do figure out that certain body parts put together in certain ways is hella fun. Later, babies come about."
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a1dyjx | what exactly is a bayou, and what makes it different than a creek or a swampy area? | I live in central NJ and there’s a muddy creek in the nearby woods; is that a bayou? Or would it only be a bayou if it was in Louisiana? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a1dyjx/eli5_what_exactly_is_a_bayou_and_what_makes_it/ | {
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"text": [
"A swamp is a piece of wet, spongy land; low ground saturated with water; soft, wet ground which may have a growth of certain kinds of trees, but is unfit for agricultural or pastoral purposes while bayou is a slow-moving, often stagnant creek or river. ",
"Could you call it that, yes. Bayou's are often outlets from a smaller water source into a larger one. They are often slow moving creeks or rivers that are secondary outlets in low lying areas. The term bayou is mostly a synonym. In terms of wetlands you have swamps, bogs, marshes and one other category that I cannot recall currently. Each of them have differences in definition, due to water type, land Mass and local Flora. \n\nCalling it a bayou would likely be strange depending on the land, but as far as I am concerned it is not much different than the pop vs soda debates. "
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ag90r1 | when is something redox / reduction / oxidatio reaction | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ag90r1/eli5when_is_something_redox_reduction_oxidatio/ | {
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"OILRIG\n\nOxidation is loss, reduction is gain\n\nIf something is oxidised it loses electrons, if something is reduced it gains electrons.",
"Technically, everything involving reduction/oxidation is also redox.\n\nREDOX simply stands for REDuction/OXidation.\n\nIn order for something to be reduced (gain electrons), something else must be oxidized (lose electrons).\n\nIf something gains a negative charge, that means it's gained one or more electrons, and is therefore reduced.\n\nIf something gains a positive charge, the reverse is true."
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dlm7eg | what makes honey unspoilable? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dlm7eg/eli5_what_makes_honey_unspoilable/ | {
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"Honey is only about 15% water which makes it very hard for microbial growth. In addition, honey is pretty acidic largely due to bee stomach enzymes during the honey creation process. Lastly, as time goes on, honey tends to crystallize into a solid, making it even harder for bacteria to form",
"I'll quote a study with \"in English\" translations\n\nA large number of in vitro (*on cells grown in a lab*) and limited clinical studies have confirmed the broad-spectrum antimicrobial (antibacterial, antifungal, antiviral, and antimycobacterial (*not just bacteria, also viruses, fungi and mycobacteria*) ) properties of honey, which may be attributed to the acidity (low pH), osmotic effect, high sugar concentration (*high concentration of things makes water run out of bacterial cells drying them and killing them, this applies for the osmotic effect and sugar concentration points*), presence of bacteriostatic (*stops bacteria from growing and reproducing*) and bactericidal (*kills bacteria*) factors (hydrogen peroxide, antioxidants, lysozyme, polyphenols, phenolic acids, flavonoids, methylglyoxal, and bee peptides) (*these are enzymes and chemicals that disrupt the life cycle of bacteria or kill them directly or help you kill them once you eat honey*) , and increase in cytokine release (*these are signals your immune system uses to communicate with itself*) , and to immune modulating and anti-inflammatory (*reduces inflammation, these things are good for you if you take honey, but don't really have anything to do with why bacteria can't grow in it when it's on a tabletop outside your body*) properties of honey.\n\nSo to answer your question, life can't grow in honey because it's a harsh environment for them due to acidity and cell drying effects and because it has things that directly kill bacteria and other microbes. \n\nEdit: English and details",
"Because the sugar in honey is heavily concentrated, it has a low [Water Activity Level. \n](_URL_0_)\n\nDespite the fact that it contains water, it is effectively too dry for organisms to grow in it and it causes their cells to become dehydrated until they stop functioning. However, being dehydrated isn't necessarily fatal for many organisms, it just stops their metabolism and stops them from growing. This is called *Cryptobiosis*.\n\nIf you mix honey with a certain amount of water, however, it will begin to ferment, creating *Mead*.\n\nIn fact, honey typically contains a variety of microorganisms such as yeasts, fungi, various bacteria. These are picked up by bees from their environment. Honey, being a natural product, isn't sterile. **EDIT**: for this reason honey is sometimes used to begin a sourdough bread culture. \n\nInfants have sometimes been known to contract certain diseases such as Tetanus, Botulism, or *Clostridium difficile* Colitis from honey. **EDIT:** these are rare to be sure but life threatening when they do occur. \n\nThese are all caused by bacteria in the genus *Clostridium* that tend to be common in the soil but can only grow in low oxygen conditions. These bacteria produce spores that can withstand dryness for years or even decades. Once they reach the intestines of s young child, this gives those bacterial spores an ideal low oxygen environment in order to grow. Infants don't have the same diversity of gut bacteria that older children and adults do, and their immune systems aren't well developed. This allows *Clostridium* bacteria to overgrow and begin to produce toxic proteins that can cause life threatening diseases. For this reason infants shouldn't be given honey until about 12 months.\n\nIn normal adults the intestines are already heavily crowded with normal gut bacteria, and *Clostridium* can't grow easily.",
"Honey is hygroscopic which means that it takes moisture around it and “eats” it up. That kills all bacteria or weird bugs. Cause they like water nomnomnom.\n\nIt’s very sweet making for a hypertonic environment. That means that all of those bacteria and things would shrivel up in the honey as equilibrium would be disrupted. Some parasites and things can make protective walls around themselves to withstand harsh conditions, but they have to survive long enough to do so.",
"It may have still been technically edible, but one of my roommates in college left a bottle of honey sitting out for an entire school year and I definitely wouldn't have eaten it.",
"Honey doesn't spoil because the germs that live in food and spoil food need to drink a lot more water than the amount of water that honey has in it.\n\nHoney can still have some germs in it that can make you sick, though. Those germs are sleeping until they get more water.\n\nThis is why babies shouldn't eat honey."
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7knj2l | how do eye dilation drops inhibit the parasympathetic nervous system? | What exactly do the dilation drops do in the parasympathetic nervous system? I've seen a post about it not to long ago but it didn't go into much detail. Could someone please explain it in more detail? Thanks! | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7knj2l/eli5_how_do_eye_dilation_drops_inhibit_the/ | {
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"The pupil is closed by ciliary muscles (round muscles around the eye), which are stimulated to contract and close the pupil by parasympathetic innervation. This signal is sent through certain receptors (muscarinic receptors). The chemical agent in eye drops bind to this receptor, but they don't cause a contraction, so they prevent the pupil from closing. The dilator muscles which open the eyelid have no opposition, so every time they open a little bit they stay open and are unable to close. "
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[]
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f7t0x2 | how is a nation’s debt tracked? | How are all the deficits, debts and loans of a nation tracked, and do they know the exact balance?
I might be very naive to how all of this works. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/f7t0x2/eli5_how_is_a_nations_debt_tracked/ | {
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"Well every borrower must be matched with a lender. The borrower might like to conveniently forget how much they borrowed but the lender is definitely not going to be of the same mind. \n\nMost countries, companies maintain sets of accounts. The most common fundamental approach to accounting is a double entry system. So everyone maintains their records that show how much they borrowed, lent, paid, received, imported and exported etc etc. Although this is a lot of information, it is possible to track debts, expenses, income etc fairly accurately.",
"In the US, the national debt is measured as the face value of US Treasury securities issued. US Treasury securities are effectively loans taken out by the US government used to finance current spending, i.e. fill holes in the budget (the budget deficit).\n\nThe budget deficit for any given year is the amount, if negative, of government revenues minus government spending. If positive, this number is referred to as a budget surplus. A budget surplus would allow to government to reduce the national debt.\n\nThe national debt can be thought of as the cumulative budget deficit of the US government."
]
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[],
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58kicm | why do cars make a ticking sound for a few minutes after turned off? | I'm a car guy myself, and even I don't really know the answer to this. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/58kicm/eli5_why_do_cars_make_a_ticking_sound_for_a_few/ | {
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"It's contraction of the various metal bits that were heated by combustion, and are now cooling. Sometimes that contraction causes an individual piece of the car to exist in either tension or compression, which is only alleviated when the force gets to great and something slips marginally. That slip produces the popping sound you hear.\n\nYou'll notice the same kind of pops if you have an oven range with resistive heating elements.",
"Typically the sound your hearing is the exhaust. Once turned off the metal immediately begins to cool and return normal from its expanded heated state. \n",
"I can only speak for VW here but many of their gas and diesel models will make a clicking noise from throttle body control module when it is running a basic setting when you turn the key off. I'd assume others manufacturers do the same but chances are what you're hearing is the exhaust like others have suggested.",
"To add to some of these comments there are solenoids that disengage after a couple minutes of your car being off. \nAnd also if you were wondering about that hissing noise, it's the low to high pressure valve (usually a thermal expansion valve). This is basically a vavle that has high pressure on one side and low on the other while the compressor(on the high side) pumps refrigerant at high pressures through it it regulates the pressure on the low side and when you turn off your AC or shut off your car those two sides of the valve equalize and that's the hissing noise your hear. It's totally normal. \nPSA: want to keep your AC healthy all year and free of leaks? Use if as often as possible even if to just defrost your windshield. Your refrigerant in your AC system also contains lubricant so when your compressor pumps refrigerant through the system, it also lubricates seals which prevents cracks in seals, pumps, and hoses. ",
"Engine specialist here.\n\nMetal contracting can cause noise, however, most of the time, in newer vehicles, the engine computer runs some tests at certain times when the engine is shut off. Different solenoids and switches make those noises.",
"It's the radiator/engine Cooling down. Might have noticed that after a really long journey the car is making that noise as soon as it is shut down and for a little while too. It's cause the best that's been built up is slowly dispersing itself away from where it's needed. \n\n ",
"I see lots of \"its the metal cooling off\" which isn't incorrect, but lacking an important detail.\n\nThat ticking is actually created by two dissimilar metals cooling off at a different rate. This creates creates friction between the parts. As the parts cool, the contract at different rates. Once the parts shrink enough to overcome the friction they experience from being bolted together, there is a ticking sound.\n\nSource: am a gearhead; dad has been a mechanic for > 40 years",
"Are you sure there isn't a bomb strapped to your car like in Casino?"
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2623tv | how do info-mercial companies that have t.v. products ever make any money? is there some kind of catch to the low prices? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2623tv/eli5_how_do_infomercial_companies_that_have_tv/ | {
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"text": [
"Shipping fees. \"Act now and we'll send you a second item for free [shipping/handling extra]\" ^$79.95"
]
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|
||
1upp85 | why can't we just gargle an antiseptic to get rid of a sore throat? | I understand it may help a little, but why doesn't it completely help? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1upp85/eli5_why_cant_we_just_gargle_an_antiseptic_to_get/ | {
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"text": [
"Because the source of your sore throat is not lying around on the surface of your throat, but within the soft tissue surrounding it. Its like saying that washing your chest with a bar of soap should alleviate a chest cold. ",
"An antiseptic kills bacteria. But a sore throat is often caused by a viral infection. A virus strongly differs from bacteria, since it is in principle only a piece of DNA (or RNA) and not a living organism like a bacterium. It uses cells as a host to reproduce itself. \n\nIt would be necessary to use antivaral drugs to stop them. The reason why they are not common to be used if you have a sore throat is probably strong side effects and to avoid new drug resistant viruses. "
]
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[],
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3x0ay7 | why do body parts get that sudden shocking feeling after hitting it on something. | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3x0ay7/eli5_why_do_body_parts_get_that_sudden_shocking/ | {
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"text": [
"I would imagine it's a combo of shocking the local nervous system along with a return of blood flow after being forced out of that local body part. Much like the pins & needles feeling you get in a limb with limited circulation. "
]
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| []
| [
[]
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|
|
2ug6gt | why don't people buy playstations and rig them for use as a computer by using linux or windows? | Playstations hardware wise are pretty cheap compared to what they're capable of.
So I was thinking, wouldn't it be beneficial to rig them up for PC use and just use the hardware?
Why don't people do this instead of buying traditional PC's?
Is it not possible, hard to do or? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2ug6gt/eli5why_dont_people_buy_playstations_and_rig_them/ | {
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"Because they don't have standard hardware. Their processors are custom and so are their video chips. Thus they would need special versions of Windows or Linux (Linux may be possible to recompile for it, if you could get the compiler). Then you'd have to write a shit load of drivers to get it working.\n\nThen, once you do that, it's actually not super impressive in terms of processing power. ",
"It happens. Notably with [the US Air Force's Condor cluster](_URL_0_), made from about 1700 PS3 units. But you'll for a large part need to customize your software for it. Not a lot of consumers are interested in doing that, and Sony has now decided to make it harder by no longer offering an official \"Other OS\" option. ",
"You used to be able to put a version of Linux on the ps3. It was pretty cool, someone created an emulator so you could play nes and snes games on it.",
"Because they do not have standard hardware, and what they do have is very much inferior to PC's. ",
"I just want to have this clear:\n\nA console is by no means cheaper in hardware to processing power than a custom built pc."
]
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[],
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"http://www.escapistmagazine.com/news/view/105767-U-S-Air-Force-Finishes-PS3-Supercomputer-of-Epic-Proportions"
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[],
[],
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|
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6o8cgj | why are performances of shakespearean plays almost never set where shakespeare set them? | I remember [The Onion made fun of this.](_URL_0_)
I could see it being a novel artistic statement the first few times, but surely the novelty's worn off by now? What did the 1999 *A Midsummer Night's Dream* movie gain by being set in 19th century Italy rather than ancient Greece? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6o8cgj/eli5why_are_performances_of_shakespearean_plays/ | {
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"Shakespeare wrote centuries ago. Our lives are very different than those of his audiences. His understanding of the human condition speaks across the centuries, but the context and the settings less so. Thoughtful recontextualization lets modern audiences get the same baseline understanding of a setting and the relationships between the opening characters that the audiences at the Globe would have had at the time. Also, the costumes can look a lot cooler. "
]
} | []
| [
"http://www.theonion.com/article/unconventional-director-sets-shakespeare-play-in-t-2214"
]
| [
[]
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|
|
ff0pzm | why do both diesel and petrol pumps have the same shape nozzle? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ff0pzm/eli5_why_do_both_diesel_and_petrol_pumps_have_the/ | {
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"text": [
"Because most people aren’t total imbeciles, quite simply. Of those who put gas in their car, a good deal of them can both read and comprehend the writing on the pumps",
"Diesel pumps won’t fit in something that takes gasoline for the most part and they are obviously marked as well.",
"It’s more cost effective to make things the same shape/parts so that you don’t have to buy twice as many replacement goods. Luckily diesel is generally always in obnoxious green color and separated from the other nozzle",
"Diesel pumps nozzle are bigger than gasoline nozzle so, you won't be able to fit it an a gazoline car. Obviously, you could still pump gazoline in a diesel car."
]
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7egps0 | why do the air from air conditioners smell different when you turn it to fan mode? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7egps0/eli5_why_do_the_air_from_air_conditioners_smell/ | {
"a_id": [
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"text": [
"Humidity. \n\nEver wonder why farts stink so bad in the shower? Humidity. \n\nAir conditioners take humidity out of the air, so you can't smell the scents in the air as well. When you switch to fan mode, no humidity is lost, so you can smell all of those scents. "
]
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| []
| [
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|
||
14z2w2 | why is black friday so far away from christmas? | I'm just wondering why it isn't in December or something. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/14z2w2/why_is_black_friday_so_far_away_from_christmas/ | {
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"Because it is the Friday after Thanksgiving and Thanksgiving happens in November. The days closer to Christmas do not need any extra marketing, people will shop on those days anyway.",
"People like to focus on one holiday at a time, and so people don't generally buy Christmas gifts when Thanksgiving is in their mind.\n\nBlack Friday is the day the collective mentality shifts from Thanksgiving to Christmas and sparks the shopping. "
]
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w5892 | why carriers care about data amount transferred--why charge us more for 5gb than 1gb? isn't all data equal? | Basically, I sit here at the computer, accessing the network, using up many gigs a month. I don't see a need to regulate how much data there is on a smartphone. Explain, please. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/w5892/eli5_why_carriers_care_about_data_amount/ | {
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"text": [
"Because they have to pay for the data transfer. Bandwith isn't free by any stretch of the imagination. Any time you want to send information anywhere, it costs money, bandwith costs a lot. They are charged for every bit.",
"Even though data isn't physical, it require energy to move from one place to another. The more data transferred, the more energy needed to move it. And of course this means it will cost more to move it as well.\n\nThe reason smartphones and other mobile devices cost more than your computer is because the physical network your computer is attached to has been established for many years. It uses physical connections and physical wires which allow more data to be transferred using less energy. Wireless internet is a very new technology and the infrastructure required to transfer this data is still being built. \n\n5 years ago it the established wireless networks were able to keep up with the demand, but when the iPhone released demand suddenly skyrocketed. Then other companies started competing with the iPhone and demand just kept going up. Only so much data can be transferred through the network at a time before it gets overwhelmed. While some companies are doing their best to update their networks to handle the capacity, many use restrictions as a stopgate against the problem. if you slow down or limit how much data each individual can use, you won't run out.\n\n",
"Imagine you are at summer camp, and there are 500 kids, but only 2 pay phones. Everyone wants to be able to call home whenever they want, for as long as they want. But, that's simply not possible, because only 2 kids can be calling at a time, and everyone else just has to wait.\n\nOne way to solve this would be to give each child an allowance of phone time every month of 10 minutes. You can use it whenever you want, but once it's gone, it's gone. That way everyone will get plenty of opportunity to use the phones.\n\nWell, in the case of cell phones, you and I are the children, and the payphones are the airwaves that cell phones use to communicate. There are a limited number of frequencies available, and a limited number of people who can use a frequency at the same time. So if it's a free-for-all, everyone tries to use as much data as they want, whenever they want; and as a result the lines get jammed, people can't make calls (or use data), and everyone is unhappy. \n\nIn order to avoid this, carriers charge more for more data, so that people will use less, and free up the lines for other customers.\n\nAt home, you don't have this problem because your data is coming to your house via cable. The company can always lay more and more cables to keep up with traffic, but there are not always more and more radio frequencies available for them to use.",
"Explained to a five year old:\n\nImagine if you, your mom, and your uncle all live on the same street in different houses.\n\nNow, sometimes you want to talk to mom without leaving your house. You have two options, you could pick up the phone to call her, or you could open your window and use your bull horn to talk to her.\n\nNow Think of your computer like it's a telephone. When you want to communicate with someone, you pick up the telephone, dial a number, and you are connected to the other line. It doesn't interfere with anyone else's telephone.\n\nI could pick up the phone, dial mom's phone, and this doesn't effect my uncle's phone at all. \n\nNow think of your smartphone as a bullhorn. When you're talking through the bullhorn to talk to your mom, you're yelling at everyone in the neighbourhood so that your mom can hear you. \n\nThe problem with your telephone, is that it's wired and stuck to your house. So you can't just walk to your car or go to the end of your drive way and use your phone. The problem with the bull horn, is that if other people are using their bull horns too to talk to each other, it will interfere and make it hard to have conversations.\n\nExplained to an adult:\n\nYour computer is connected through a dedicated network, where information is streamed via wires. There is much less interference when data is travelling through one wire to interfere with another wire. For the sake of simplicity, let's just say that when you're using the internet at home, there is only your data being transmitted to and from your ISP.\n\nOn a cellular network, you're broadcasting data from your smartphone to a cell tower via radio waves. The way it does this, is that it broadcasts the radio signal EVERYWHERE in that area.The problem is, everyone in that area who wants to use their phone also broadcasts a radio signal, and they all share the same radio tower. It's as though everyone is on their bull horn trying to talk to one another, but because everyone is talking at the same time... there is interference. A cell tower can only support a limited number of concurrent users.\n\nData is not all equal... it depends on the transmission mechanism. "
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5y1n4f | the vault 7 cia leaks | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5y1n4f/eli5_the_vault_7_cia_leaks/ | {
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"Is there anything specific you want to know about? It's a very big leak and one that people are still sifting through - there is a lot of misinformation going around though and I'd love to help people understand where I can to stem that.\n\nTLDR: Wikileaks have come into possession of some data from one of the CIA's Confluence servers. Confluence is basically a Wiki for companies and orgs to use to document stuff/work together, so it has a lot of information on their tools and procedures. There is apparently more leaks to come."
]
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3ulv7h | how microwaves work, such that my leftover gravy boils on my plate while my lump of cold mashed potatoes stays cold? | Eating leftovers, obviously. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3ulv7h/eli5_how_microwaves_work_such_that_my_leftover/ | {
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"Microwaves are at the right frequency to cause water molecules to vibrate, increasing the temperature of the food. Gravy contains more water than mashed potatoes, which are relatively dry, so gravy heats up much faster.",
"In addition to the density of water molecules as /u/therhythmofthenight mentions, because microwaves make micro**waves** there is often parts in the microwaves where [Standing Waves](_URL_0_) are created. In a node of a standing wave, the waves cancel each other out and there is no effect. Most microwaves turn your food to counteract this, but often it is part of why some of the food is colder than other parts",
"Heat capacity of anything with lots of water in it, is what I would think causes the gradient in temperature in the foods you microwave.\n\nAlso, the fact that standing waves occur can also affect heat distribution in microwaves. \"*Microwaves have wavelengths approximately in the range of 30 cm (frequency = 1 GHz) to 1 mm (300 GHz).*\"\n\nSo the standing waves can create heat distributions along that approximately 30cm-1mm range. The lower the frequency of the microwave in question, the greater the difference in heat across its distribution. The solution to this is moving your food in a circular motion :).\n\nThus, I would think it's most likely got to do with the differences in heat capacity of the foods you're heating up. I try to put small plates over any bowls I put in the microwave, so I can trap all the heat and make what I'm microwaving a more consistent temperature all-over."
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59upvm | can a human survive eating only dog food? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/59upvm/eli5_can_a_human_survive_eating_only_dog_food/ | {
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"Physiologically speaking, appetite fatigue isn't a thing. As long as your diet has the nutrients to sustain you, you will live - psychologically speaking, however, you may say \"fuck it\" because you're eating dog food, and start humping legs for scraps under the table.\nWhat a strange question to ask..."
]
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1km27d | how does electric power turn into mechanical force which rotates gears and operates our machinery? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1km27d/eli5_how_does_electric_power_turn_into_mechanical/ | {
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"The flow of electric charge creates magnetic fields. For example, if you make a circular loop of wire and run a current through it, it makes a magnetic field that's in the same shape as a bar magnet.\n\nSo, a motor works by simply exploiting that fact. The electricity makes magnetic fields, and you use those magnetic fields to push around permanent magnets, causing motion.\n\nSomething you might make in lab if you ever take an introductory physics course is a motor like [this](_URL_0_). By running a current through the loop of wire, you cause a magnetic field to form. The magnet on the bottom repels/attracts the field caused by the wire loop, so the loop starts spinning. Technically, you need to sand the lining off of the wire so that current only flows through it half the time, but that's the basic idea."
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6gwugq | why do paper mills smell so awful? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6gwugq/eli5_why_do_paper_mills_smell_so_awful/ | {
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"A lot of that smell is from effluents from the bleaching process and the busting down of cellulose process. Caustic chemicals and highly corrosive salts are used to turn tree pulp into pillowy soft sheets for your ass. The resulting mess is dangerous and goes through some reactions to lessen the pollution when they dump this shit back into the environment. "
]
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[]
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||
biofuu | how do modern vehicle speedometers work? tire rotations per minute? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/biofuu/eli5_how_do_modern_vehicle_speedometers_work_tire/ | {
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"Yep, tire rotation. Knowing the diameter of the tire and multiplying that by pi gives you the distance traveled per rotation. That means that if you do anything to increase the diameter of your wheels, you need to also get your odometer adjusted, or else you will actually be driving faster than your car thinks you are going.",
"How much error is introduced by tire wear? New tire vs old worn tire...",
"It's already been answered, but most vehicles now have a VSS (vehicle speed sensor) that measures pulses on the transmission, and does math of the tire size to figure out speed.\nYour wheels might also have speed sensors to ensure ABS and traction control work, but these are not used to determine vehicle speed.",
"I just answered this in a different question. But in short, yes:\n\n_URL_0_"
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"https://www.reddit.com/r/askscience/comments/bimebt/should_i_trust_the_spedometer_of_my_car_or_the/em2gvbz/"
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24ehb3 | how are segmented voices (those on gps's, automated phone responses, etc.) recorded? | Does a female literally just speak phrases/numbers into a microphone for hours on end? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/24ehb3/eli5_how_are_segmented_voices_those_on_gpss/ | {
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"text": [
" > Does a female literally just speak phrases/numbers into a microphone for hours on end?\n\nYes. Or a male.\n\nIn fact, [you can make your own](_URL_0_) if you've got a microphone and a lot of free time on your hands. You record however many sentences you want (at least a thousand if you want decent quality) and then let the program process it for a long, long time, and voila: You are now an immortal robot voice."
]
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| []
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[
"http://www.circumreality.com/TTS.htm"
]
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|
|
5mdslz | how does out brain manage hormones? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5mdslz/eli5_how_does_out_brain_manage_hormones/ | {
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"Most hormones are stored throughout the body IE insulin pancreas, adrenaline kidneys. The brain monitors the levels of these hormones in the body, when a hormone release is required the brain essentially fires an electrical impulse that triggers the release of these hormones. \n\n"
]
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| []
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[]
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n7gq6 | how stuxnet worked, and what it may mean for either america/israel or russia to be behind it | Seems very interesting, but even the [TED talk](_URL_0_) muddled it a bit for me. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/n7gq6/eli5_how_stuxnet_worked_and_what_it_may_mean_for/ | {
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"Stuxnet was custom-designed software specifically created to work for a Siemens centrifuge system. It worked by periodically changing the rotation rate of the centrifuge (increasing speed beyond recommended values for enriching uranium) to destroy the uranium samples and the centrifuge mechanisms themselves. The intent was to prevent the operators of the equipment from using it and, hence, slow the amount of uranium that could be enriched and extend the time required to gather enough enriched uranium useful for a nuclear weapon.\n\nThe meaning of having a nation be behind it means that warfare has very definitely moved into a new vector (cyberwarfare). If the Cold War was anything to go by (lots of behind the scenes maneuvering between the Eastern and Western blocs) then they haven't seen anything yet.",
"From my understanding:\n\nThe virus was one of the first to adapt to its environment. It started off being infected on one of the workers USB drives left in their car. When that person plugged the USB drive in to the facility's computer, then it would know to move to the new host. What's remarkable about this computer virus is that it knew exactly what its target was. It would figure out what type of machine it was on, and then determine the best way to move on up the chain of computers until it finally reached its target. In this case, the target was a Siemen's micro controller for Uranium enrichment centrifuges. Once the virus had infected the firmware of the microcontroller, it could do whatever it wanted with it. The virus would speed the centrifuges up way beyond their operating limits, causing them to break, and then delete the system logs of this happening. By deleting the logs, the plant engineers had no idea why the centrifuges were breaking, on top of it was very difficult to catch it in the act. The purpose was to delay the plant's production for as long as possible. I believe this went on for at least a year and eventually the director was fired because things were taking so long. Another thing of importance was that Stuxnet used around four zero-day attacks. A zero-day attack is an exploit that nobody else knows about, so it will be a complete surprise. You can only use such an attack once since they are fixed ASAP once revealed.\n\nDue to the complexity of its creation, it has to have been created by a nation. It was written in a combination of languages, including some very low level assembly code. The knowledge of the zero-day attacks and Siemen's architecture raises some flags too. IIRC it was digitally signed which means that it looked like a legitimate program to the infected computer. I would think that such sabotage could be considered an act of war, especially when you look at the damage it caused the reactor. Stuxnet showed how vulnerable some computer controlled equipment are, and I'm sure there will be many more incidents like this popping up in the future.",
"Stuxnet was custom-designed software specifically created to work for a Siemens centrifuge system. It worked by periodically changing the rotation rate of the centrifuge (increasing speed beyond recommended values for enriching uranium) to destroy the uranium samples and the centrifuge mechanisms themselves. The intent was to prevent the operators of the equipment from using it and, hence, slow the amount of uranium that could be enriched and extend the time required to gather enough enriched uranium useful for a nuclear weapon.\n\nThe meaning of having a nation be behind it means that warfare has very definitely moved into a new vector (cyberwarfare). If the Cold War was anything to go by (lots of behind the scenes maneuvering between the Eastern and Western blocs) then they haven't seen anything yet.",
"From my understanding:\n\nThe virus was one of the first to adapt to its environment. It started off being infected on one of the workers USB drives left in their car. When that person plugged the USB drive in to the facility's computer, then it would know to move to the new host. What's remarkable about this computer virus is that it knew exactly what its target was. It would figure out what type of machine it was on, and then determine the best way to move on up the chain of computers until it finally reached its target. In this case, the target was a Siemen's micro controller for Uranium enrichment centrifuges. Once the virus had infected the firmware of the microcontroller, it could do whatever it wanted with it. The virus would speed the centrifuges up way beyond their operating limits, causing them to break, and then delete the system logs of this happening. By deleting the logs, the plant engineers had no idea why the centrifuges were breaking, on top of it was very difficult to catch it in the act. The purpose was to delay the plant's production for as long as possible. I believe this went on for at least a year and eventually the director was fired because things were taking so long. Another thing of importance was that Stuxnet used around four zero-day attacks. A zero-day attack is an exploit that nobody else knows about, so it will be a complete surprise. You can only use such an attack once since they are fixed ASAP once revealed.\n\nDue to the complexity of its creation, it has to have been created by a nation. It was written in a combination of languages, including some very low level assembly code. The knowledge of the zero-day attacks and Siemen's architecture raises some flags too. IIRC it was digitally signed which means that it looked like a legitimate program to the infected computer. I would think that such sabotage could be considered an act of war, especially when you look at the damage it caused the reactor. Stuxnet showed how vulnerable some computer controlled equipment are, and I'm sure there will be many more incidents like this popping up in the future."
]
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| [
"http://www.ted.com/talks/ralph_langner_cracking_stuxnet_a_21st_century_cyberweapon.html"
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[],
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5ahcfe | when we look at stars/planets, are we actually looking into the past? | ELI5: This has always confused me. Since the view of the star is traveling at the speed of light, it has taken many years to reach Earth.. So for all we know, that star/planet could be long gone, correct? If this is the case, how is the information we are receiving from things light years away reliable at all? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ahcfe/eli5_when_we_look_at_starsplanets_are_we_actually/ | {
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"Something weird TOTALLY COULD have happened and that distant star blew up or something, and we just haven't seen it happen yet.\n\nWe assume the information is reliable though because galatic-level \"oh jeez what was THAT\" is relatively uncommon. Stars keep shining until they run out of fuel (and we know what that looks like), planets keep orbiting, galaxies keep rotating. It also takes a loooooong time for big events to happen in space, entire galaxies can collide and be ripped apart but it'll take eons, and we'll be able to see their crash course millenia before it actually occurs.\n",
"Technically, any visual information you receive is from the past because it\n1.) Takes time for light to emit from a light source\n2.) Takes time for light to strike an object and bounce back\n3.) Takes time for your brain to process the information\n\nThis makes the concept of the present relative to our ability to process information, I guess.",
"That information is perfectly reliable as long as you account for that time/distance. It's an accurate representation of the object's past, and due to the speed of light, there is no possible mechanism of knowing anything more recent.\n\nIn a technical sense, this is true no matter what the distance. If we're standing face-to-face, the information I perceive about you is always very slightly wrong. It's just too small a difference to be important (or perceptible).\n\nAnother interesting point is that half of the exoplanets we've confirmed are within just 1,000 light-years, so our knowledge of them is probably very close to accurate (considering that our knowledge extends little further than their existence and orbital characteristics). We've found a relative handful of more distant exoplanets, up to 22,000 light-years out, but even on that time scale, of the things that we could even observe from such a distance, very little has probably changed.",
"Everything you see you are seeing in the past. If you look at your hand, you are seeing your hand in the past, the same as a distant star. Now, obviously, not *very far* in the past. The speed of light will essentially tell you the travel time light takes from your hand to your retina. Then add a bit more onto that for your brain to interpret the light information it has received and 'make a picture.'\n\nCertainly stellar objects are the 'furthest back' you're likely to see, although bear in mind that every specific object you can see with the naked eye is relatively close in 'space terms.' Maybe some tens of thousands of years back at most. It's unlikely any stars are long gone on such a time scale, because that's a blink of an eye for a star's lifespan.\n\nWhen it comes to something like holding a conversation with an alien species, any realistic distance is likely to be prohibitive. Even our closest possible neighbors would likely need years to exchange replies. "
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427mca | the water crisis in michigan | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/427mca/eli5the_water_crisis_in_michigan/ | {
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"Flint used to get water from Detroit (which gets the water from Lake Huron). \n\nPoliticians wanted to save money and use the Flint River instead. Despite a study that said it was not a good idea, they got switched to Flint River water.\n\nThe Flint River was a lot more corrosive than Lake Huron.\n\nThis leeched a LOT of lead out of the city's aging water pipes (newer pipes don't have lead in them).\n\nNow they can't use any water through those pipes because the corrosive river water makes the pipes put lead into any water that goes through them, requiring a lot of new pipes to be installed, and people getting lead into their system (which is incredibly bad).",
"My very simplistic understanding is that someone in Flint's water utility decided they could get water cheaper by drawing it out of the Flint River than by buying it from Detroit. \n\nIt came from Detroit through old pipes that contained lead. This wasn't a problem because Detroit's water had chemical properties that coated the pipe and prevented lead from entering the water supply in any large quantities.\n\nThe water drawn from the river through those same pipes has a different chemical makeup and ate away at the 'coating' that the former water supply had formed, allowing lead from the pipe to enter the water supply.\n\nEDIT: We know that any amount of lead in drinking water is unsafe. There is so much lead in the water that people have come down with skin irritations and possibly worse."
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cejzmc | what is happening when the computer loading bar takes way longer to complete the final 1% during the installation process. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cejzmc/eli5_what_is_happening_when_the_computer_loading/ | {
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"Generally, a progress bar doesn't work how you think it does (and each different bar may be measuring different things).\n\n & #x200B;\n\nGenerally the ones that stick at the last 1% are cleaning up whatever was downloaded. When you are downloading something to C:\\\\ it's probably downloading to a temporary directory somewhere (like Temporary Internet Files or c:\\\\temp). When it finishes, the last step is to move it to the place you wanted it to go in the first place. That last 1% is the time it takes to move it and close the connection.\n\n & #x200B;\n\nSome progress bars are based on number of items, and not amounts of data. So if you're moving 2 files, the first file is 1 MByte, and the second file is 1 TByte, when it finishes that first file, it will move to 50% because it has completed 50% of the files, even though it's not 50% of the data to be moved.",
"loading bars are manually programmed, and not based in any quantitative value on your PC. Sometimes they are based on the amount of data downloaded compared with the filesize of what you're trying to get, but you also have installation loading bars - How do you know what exactly is 20% of the bar? Or 10%? How does setting up registry keys match up with file downloads or playing your stuff in program files(x86)?\n\n\nAny glitches you see on them are a result of either bad gui coding or of something in the back-end of the software changing without the front-end being updated."
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1dl62x | in public-key cryptography why can the message encrypted with the public key not be decrypted with the same public key? | I understand that the sender of the message encrypts it with the recipients public key, which can be freely accessible by anyone.
Why can the same public key used to encrypt the message not be used to undo / reverse the algorithmic function that encrypted the message?
From what i understand the sender uses an asymmetric key algorithm to encrypt the message. If the algorithm used to do this is known and accessible to any sender wanting to send a message, why can the knowledge and understanding about this algorithm used, combined with the key used for encryption, not be used to decrypt the message?
In symmetric key cryptography, a message encrypted with a key can be decrypted only with the same key (and maybe a collision), and nothing else.
So for asymmetric key cryptography, how can you decrypt a message with a completely different key, and how is it that encryption with a public key can't be reversed using the same public key?
How does an algorithm work that produces non-reversible cyphertext, unless you have another unrelated private key? And if the function and workings of the algorithm are transparent and accessible, how can that knowledge not be used to decrypt cyphertext using the same key?
I think i am completely oblivious to some obvious fundamental basic ideas of cryptography here, does someone care to educate me? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1dl62x/eli5_in_publickey_cryptography_why_can_the/ | {
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"think of very long oval track, and think of each step around that track as coding the message... but it does it in such a way that when you get all the way around the track back to the start, the message is back where it started too... so it is this cycling process of coding, and getting to the point that it codes back to the original message. Try keeping that in mind.\n\nThe two keys add up to the length of the track, but the length is kept secret along with one of the keys.... so one key starts the coding process and the second key \"finishes\" it by getting back to the original message. Knowing how far to start (the public key) gives you no information about how far you have to go. \n\nFiguring out the length of the track would destroy the code, and in this scheme the length is (p - 1)(q- 1) where the two primes for coding are p and q, so all you have to do if figure out p and q... but that is very hard. So the code is secure. ",
"It uses something called a trapdoor function, that is easier to computer in one direction than the other.\n\nFor example, it is really easy to square a number. If I asked you to computr 17^2 , it probably wouldn't take you very long to figure it.\n\nBut take a square root of 306, that is a lot harder problem, and it would probably take you longer.\n\nPublic key encryption works the same way, only encryption using the public key is mathematically equivalent to multiplying two large prime numbers together. Decryption using the public key is like taking a very large number, and figuring out which two prime numbers multiplied together made it. Doing that is famously difficult."
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42ih1m | can you climb from earth to space on a cable? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/42ih1m/eli5_can_you_climb_from_earth_to_space_on_a_cable/ | {
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"hypothetically, yes. but we don't possess the technology to achieve this. what you're talking about is basically a space elevator.\n\n_URL_0_",
"Yes, assuming such a cable exists. You could achieve escape velocity climbing a ladder, if we had some sort of magically tall ladder. "
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3ez3tb | why stores like the 99¢ store are able to sell products that you can find at regular grocery stores, but much cheaper? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3ez3tb/eli5_why_stores_like_the_99_store_are_able_to/ | {
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"Their costs are lower for one. They don't stock premium brand names. They also sell smaller packages of products. They also have smaller stores, meaning smaller overhead for rent and heating and personnel. \n\nAnd when you realize retail prices for general goods are set 30-50% above cost typically. So of course a lower cost lower profit margin store can make it profitable.",
"Many of these stores stock items that are already available for around $1 at regular grocery stores in the first place.\n\nAnother reason is that you usually don't see the big name brands stocked at dollar stores. They sell generic brands, which can afford to sell for cheap. \n\nAnother reason is that if a store wasn't able to sell those items, they will turn to the dollar stores to help them sell the overstocked items for cheap. \n\n",
"Some of the items they sell would cost a dollar almost anywhere. Some might cost more. However the cost of most of the merchandise is much lower than a dollar, though some of it might be at cost/break even \"premium\" items that get you in the door and looking around. Because they buy huge bulk quantities of clearance items or direct from the manufacturer they pay a fraction of the wholesale price. \n\nIf the consumer perceives value than they will typically spend more thinking they are getting a bargain. \"What the fuck, it's just a buck?\" is what's going through your head, so you buy more cheap crap than you intended. Since you are used to paying a premium on shoddy disposable goods you are in fact saving money, which makes it likely you will return and be a repeat customer, making the dollar store a tidy profit. \n",
"One of the major reasons involves what are called Parallel Imports. In Australia, what that means is seeing Colgate toothpaste being sold in a 'dollar store' at half the price of the major supermarkets.\n\nThis toothpaste is usually made for the Asian market (as evidenced by the Thai or Vietnamese small print on the box/tube). In a case where the original market has a glut of a product, they will send it to Australia to sell cheaply. Keeping in mind that the product would have sold for much cheaper in the original market (or in the case of a crazy over abundance of the product, not sold at all), this is a cost saving strategy.\n\nThis is a grey area of law, and is reflected by the fact that it is often called The Grey Market. The distribution is not illegal, but is unauthorised and not the originally intended distribution channel of the manufacturer. \n\nSometimes the product will be exactly the same as the one being sold in the big supermarket, but usually there is something just a little bit different - like the taste or smell. This difference between markets reflects the 'tastes' of the markets.\n\nI can't stand that Vietnamese toothpaste, but it's so cheap... ",
"A lot of the inventory of dollar stores is bought as overstock, for sometimes fractions of a penny on the dollar, from companies who just need to get merchandise off their hands as quick and easily as possible. \n\nSay a company suddenly needs to clear out some warehouse space to make room for a new product, or a retailer decides to stop carrying a product and they still have a ton of it on-hand, or you noticed too late that a whole production run of your product has some kind of mistake on the packaging, or you're a distributor of something and going out of business and it would take too much time to parcel everything in your inventory piecemeal and just want to get rid of it. \n\nThere's always going to be situations in life where you want to get rid of something right away but think it's too valuable to just throw in the garbage. For the belongings of an average person, ways to easily get rid of some stuff include pawn shops, craigslist, or donating to goodwill or salvation army. If you're a business and those belongings are consumer merchandise, you probably sell it to a dollar store or to an overstock vendor (Big Lots, Marshalls, TJ Maxx, etc).\n\nDollar stores buy stuff at an enormously discounted rate, sometimes even negotiated per pound of product instead of per unit. They often are losing a lot of money on the sale, in order to make the inventory just go away. Some times, the people they buy from would probably pay *them* just to come haul the stuff away.",
"I've seen prices for food items such as El Montery burritos and some pizza higher at the dollar store than walmart. "
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19ofmn | what happens if: i lose a court case, and i'm ordered to pay the opposition lawyer's fees but i'm completely broke? | By broke I mean, no money, no assets, nothing. What happens to the lawyer's fees? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/19ofmn/eli5_what_happens_if_i_lose_a_court_case_and_im/ | {
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"First of all, there's insurance available for this. So if you win the case, you'd pay some degree of your winnings to the insurance company, while if you lose the case, they cover your costs.\n\nOtherwise, you're going to have to declare bankruptcy. That will, of course, ruin your financial status for a period of time.",
"Depends on where and what kind of case.\n\nIf you it is a case that is insured (i.e the insurance company takes over pretty much the case, from which lawyers to use etc.) they will cough up the dough on your behalf, and then give it to you sideways through premiums.\n\nIf you are not insured, then the lawyers have a range of remedies. They will usually issue some sort of demand. Based on this, they may try to garnish your wages/salary, or as said by the_omega99, apply for bankruptcy proceedings against you.\n\nThat said though, lawyers will advise their clients pick their targets wisely. They *usually* won't go after someone who they know is broke or can't pay the damages and cost."
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4danmf | why do americans not trust their police? | Here in the UK I very much trust the police to do their job and as far as I know they're not corrupt at all. From what I gather in the US the police always seem to try and screw you over? Is this true? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4danmf/eli5_why_do_americans_not_trust_their_police/ | {
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"It really really depends. \n\nI've personally never feared the police. My experiences have been nothing but positive. I live in a rural area. \n\nMany of the complaints come from urban areas. Sometimes it's corrupt officers, sometimes corrupt departments. Sometimes it's the public emotion running away with a situation and perhaps putting too much blame on officers. All of these cases happen.",
"While I've never had problems with the police personally, from news stories, they do seem to have a real problem with wanting to protect policemen who abuse their power. I know that news usually only reports negative stuff, but it still does happen, and can give people the impression that they're not to be trusted.\n\nAlso, to be honest, racial profiling is still very much a thing. I work with a few black people and most of them have been pulled over simply because they were a black person driving a nice car. Even Neil Degrasse Tyson has a couple of stories where this happened to him.",
"[Here's a poll](_URL_0_) that shows that confidence in the police is at it's lowest since 1993 (when we had HUGE issues with crack/cocaine and there were a lot of raids based on that). However, only 18% of the population have little to no trust in the police. \n\nAlso, the US is huge. You are going to get a varied amount of opinions based on age, race, sex, religion, and geographic location. Population wise, the USA has five times the amount of people of the UK. Geography wise, the US is two and a half times bigger than Europe. Although in the UK, you might have trust in your police force, many people in Germany (particularly after the whole New Years incidents) might have a very different perspective. The same goes for the US - although one state might be perfectly fine with it's police force, another (Illinois) might have huge issues. ",
"Sometimes the media will grab onto a handfull of police brutality stories and blow them way out of proportion as the media is known to do. I'm not saying that they dont happen just that sometimes they are made to be a bigger deal then these stories actually are. ",
"This is personal experience so I'm not necessarily a reliable source/narrator. But like most groups the police force is well known to treat the wealthy differently from the poor, the colored different from white, etc. And they get away with it for the most part. I'm lucky. I'm a white woman in a rural area, so for the most part I can escape some harassment. But at one point in time I was living in Public Housing, and it was immediately obvious that my treatment by police was different. When I was married with a military officer husband, my house got broken into and the police were helpful and gracious. They called and gave follow ups on our case and even found and returned some of our possessions. When my apartment got broken into in public housing the police actually accused me of stealing my own laptop... They never followed up, they were patronizing and rude. I was scared and they didn't help. And this is pretty common.\nFor years the police have been treating minority groups poorly, stereotyping them, getting away with unjust practices, and people are really starting to protest. Impoverished people and groups just don't have the money to take on the legal system and protesting a system that can literally ruin your life is a frightening prospect. Officers have proven lately that they can kill with immunity and the worst that will happen is they will get paid vacation until it blows over. I don't know how it is in other countries, but cops don't create a feeling of comfort and safety for me, but one of anxiety and concern. \nI have no idea of this helped or not.",
"Reddit is representative of younger redditors, who base their perceptions of the world from what they are shown on news and social media. \n\nOlder redditors tend to base their perceptions on their environment and personal experiences.\n\nIf you polled reddit right now, you'd probably get like 50% trust police in general, 25% distrust police in general, 25% loathe police. \n\nIf you polled a 50+ community, it would probably be 90% trust police in general, 8% distrust police, and 2% hate police. There's also a large racial disparity in those numbers. \n\nIt's a misnomer to say most Americans distrust police. MOST don't. The traditional media has taken to airing news stories of police misconduct and abuse because it resonates well with a large portion of their viewership. Even so far as to push a racial persecution element where it is not a factor, or giving deference to obviously incorrect information. (See: Michael Brown)",
"I think problems with police (in western countries) are usually less about out and out corruption, and more about many police departments having a fucked up culture of being above the law, treating people like crap, being petty, having no accountabilty, etc.\n\nFrom what I've seen UK cops have a much better culture of being respectful and serving their communities, compared to US cops. There might also be different expectations, reactions to cops, or other factors at play.",
"This is just me but I dont trust anyone. Most officers I have interacted with have been nothing but professional, but it only takes 1 bad officer to make your life shit and I always try to prepare for that 1 bad officer",
"Reddit does not equal the US. Most Americans (when you exclude Reddit and minorities) trust the police. ",
"90% of people do trust the police. It's the media mostly that acts like we don't. And also people in small towns that number goes to like 99.999% of people that trust them. It's only in big cities where there is a ton of crime that people claim to trust the police. "
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fw1yi7 | how do trees decide when and where their branches grow? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fw1yi7/eli5_how_do_trees_decide_when_and_where_their/ | {
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"The full answer is pretty complicated, but the short version is that plants have hormones just like animals. They have growth hormones and the ability to sense light and the direction of gravity. Most plants try to grow towards light and against gravity. Many plants also grow more in the summer because they sense that the days are longer. There have been experiments done with plants kept in similar environments but with different durations of light, and it was found that you can cause certain plants to bloom depending on how long the lights are on.",
"Trees communicate using different hormones. These hormones are made by leaves and branches in response to different conditions such as different types of light, temperature, humidity, stress and gravity. These hormones then affect how the other branches grow depending on their genetic encoding. And this determines the shape of the tree. The hormones may also be transfered to different trees either through the air or the roots and therefore shape the entire forest. This is an area of very active research where we study how different plants grow in different conditions and also check what different mutations does to the growth patterns. On of the most exiting new innovation in this work is that the ISS recently got a small greenhouse allowing us to grow plants without the effects of gravity. Not only will this allow us better understand the effect of gravity on plant growth but by removing the effect of gravity we can better see other effects that might be hidden from us.",
"DNA/genes. Their genetic code says to \"be like a tree\" and that means growing roots to absorb water and nutrients from the ground and to hold firmly in place, expanding the thickness of the trunk, and to reach up towards sunlight and produce a lot of leaves to absorb sunlight and carbon. Since it needs lots of leaves, it needs many branches. It's pretty tough for DNA to code perfect symmetrical shapes and growth (like a perfect sphere or circle where the branches are *too* perfectly spaced) so it says to sort of grow for a while and then split a new branch \"sometimes.\"\n\nThis results in near-fractal-like structures, which is where the pattern of branch-smaller-branch repeats, but not at perfect intervals. That's why most trees of the same type look similar but aren't exactly the same. The branches split and new ones form at frequent, but imperfect intervals. This psuedo-randomness is actually quite pleasing to look at, like music: music has repeating patterns (like a chorus) but with small variations to prevent boredom. These patterns likely help attract all different kinds of life that the trees also need to thrive by spreading their seeds and nuts and fruits around and producing waste to enrich the soil. \n\nAlso, by somewhat randomizing the growth patterns, leaves can fill in more spaces and probably absorb the most sunlight this way by creating a more full canopy. Imagine sticking toothpicks into an apple, straight out from the center, and then extending those toothpick lines out for another foot. If tree branches grew straight out at perfectly spaced intervals, their branches would eventually spread away from each other and leaves wouldn't cover as much area to soak up the sunlight. It also makes for less interesting places for animals to make their homes.\n\nSo they grow in a psuedo-random pattern, which is a lot like fractals with small variations. If you don't know what fractals are then please check out a good YouTube video on them, it is beyond the scope of this question.",
"To complete and go more in depth on what was already answered, it is a mix of influences from genetics and environmental conditions (as for everything in biology actually). A stem or a branch usually end with a bud (called apical bud) which contain a special group of cells called a meristem. Meristems are where cell multiplication happens in a plant and so are what allow a plant to grow. During the growth season, this apical meristem will produce new cells at the base of the bud and those cells will then elongate, which will make the branch grow longer. As others said, this process is controlled by hormones (the principal one being called the auxin), and those hormones are strongly sensitive to the environmental conditions. For example, light destroy the auxin, which will make the shadowed side of a stem grow more than the other side and the stem will \"go\" toward the light source.\nEvery now and then during this period, the meristem will produce a leaf and on the top of the junction between the leaf and the branch, a little piece of meristem will separate to create a new bud (called axillary bud). This bud will stay dormant until the next growing season (where there is different seasons) and then it will start to be active the same way as the apical bud (it actually is an apical bud at this point) and develop into a new branch. The rhythm and the places the leaves and the axillary buds will be produce is mainly controlled by genetics.\nSo to summarize, environmental conditions like light (but also wind, gravity, animal grazing,...) control the shape of the branches and where they go, and genetics controls when and where a new branch is produced.",
"And how do they balance their branches?. Eg. Counter balance with branches on the other end.. Thickness of branches.. Etc.",
"Anyone else automatically think of decision trees learning?",
"Trees don't \"Decide\" anything just like you don't \"decide\" to let your heart keep beating, and at what bpm. \n\nAll flora operate under hormone induced involuntary actions exacerbated by ecological surroundings.",
"Trunk grows up.\n\nBranch comes out a side.\n\nNext branch needs to grow out a different side, to not block light to the first branch.\n\nNext branch again needs to grow out a different angle, to not block light going to first two branches.\n\nSo branches need to grow out at an angle that minimises interference with previous branches.\n\nTurns out, the best angle is the golden ratio.\n\nInteractive version here\n_URL_0_",
"Think of it like survival of the fittest. Trees send out multiple branches each year. The branches that get the most sunlight, survive.",
"The trunk as it grows up taller and wider will grow some new places where branches might go. The trunk decides how often to make new branches by following a bit of math that tells it to make branches only as often as necessary to create armfuls of leaves that will cover the sky without covering each other. The trunk knows that branches it has grown are still alive because the leaves at the ends make a...well let's call it a smell. As the Sun shines on the leaves and they grow they make a smell that the trunk can smell and that way it knows the branch is alive and won't try to grow another branch at that spot. If the trunk doesn't smell any leaves coming from a branch, it may start to try growing new branches in that spot. When a tree is cut down and only the trunk is left it won't smell any leaves at all coming from above and it will try to grow branches all over the place to start anew. We call these \"suckers\" coming from the old stump and if they are left long enough then one of them will grow bigger and make many leaves and the smell of those leaves will come down to the stump and it will stop growing the other suckers and focus only on growing that one successful sucker and that's how a tree may recover from being cut down.\n\nSo, in very short, leaves make a sort of smell that tells the trunk that it doesn't need to grow another branch in that spot. The trunk will create new branches above old branches as it grows taller according to some basic math that helps it to spread branches out so they don't overlap and cover each other from the Sun.",
"The answer to this is hugely complex and dependent on the species of tree among other things. The hobby/art of Bonsai is pretty much all about controlling where and how the branches on trees grow to produce an old looking tree in miniature. The vast majority of how this is done is around your question. Masters of the art have degrees in biology and spend 6+ years in apprenticeships as well as dedicating their life to learning how to do it efficiently. You can probably get an ELI5 for one specific species of tree but it will take 30+ minutes to explain it so not sure even that would be simple enough to qualify.",
"Want a real ELI5? They’re living beings too, and they just know. Just like how your body grows without you needing to tell it to",
"As mentioned by others, hormones. The lead of a certain growth, like the top of the tree or the tip of the branch, it produces a hormone that hinders growth of new branches. When it has grown far enough from where a new branch would sprout, the concentration of that hormone is low and as such less effective, eventually low enough fow a branch to grow.",
"Have you ever thought about how boring it must be to be a tree? You literally just stand there, and your leaves always make it cold for you cuz you’re permanently in the shade. Therefore, trees go where the sun is, and sometimes they do some funky stuff with their limbs to show off to the other trees.",
"By default, trees want to make branches everywhere, but the top of the tree sends a signal down saying, \"no!\" As the trunk grows higher, the lower parts of the tree start to have trouble hearing the top and start to grow a branch. That branch turns into a mini-trunk, also saying, \"no!\" to all the other parts of the tree thinking of making a branch. This keeps happening over and over again. Different trees have louder tips, parts that have better or worse hearing, and parts that eventually decide to stop growing, which is how we get so many different shapes of trees.\n\nTree top shouting = auxin and other hormones released from meristems.\n\nRest of the tree = active layers of cells just under the bark / dermis.\n\nListening = genetic regulatory responses to the auxin / hormones.",
"ELI5 version:\n\nTrial and error. Tree needs light and water. Tree grows towards light and water.",
"Also related, the Fibonacci Sequence.\n\n1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377...\n\nIf you divide each term by the previous, you get\n\n1, 2., 1.5, 1.66, 1.6..., all converging on 1.618..., the golden ratio.\n\nIf you start at one point, shoot a branch, then turn 1.618...times around the trunk and shoot another, and go along that way, you get the most efficient structure for a plant to produce a canopy for maximum top down area.\n\nWhich is really weird.",
"Plants are not actually inanimate objects, they just move very slowly and don't have the kind of brain that can make particularly complicated decisions.\n\nPlants are able to communicate with each other. There's a variety of acacia tree that can produce poison (tannins), but it's expensive to make, so it doesn't normally create much of it. But if an enemy starts to prey on one, the tree will release a smell that makes the rest of the acacia trees around know that shit just got real and they'll all arm themselves with tannin for the entire area, a pretty good way to get animals to eat something else. It's even more interesting because a human can break a branch off the tree without causing the \"we're being eaten\" alert to go out like it does when an animal starts munching its leaves. The poison isn't just a blind response to any and all damage, but only to things that seem like an animal eating the tree. And communicating saves the trees from all having to produce the poison constantly which would cost them energy.\n\nThere are other plants that have teamed up with parasitic wasps. When a caterpillar (the wasp's food) starts to eat the plant, the plant releases a special smell that shouts \"wasp dinner time\" and the wasp comes over and ganks the caterpillars for it.\n\nEven mushrooms are in on the intelligence and communication, Leafcutter ants actually communicate with their mushroom farm partners. If the ants bring back a poisonous plant the fungus can't tolerate, the fungus tells the ants to toss that crap away and the ants will get rid of the poisonous plant for them. Win-win for everybody.\n\nThere's a plant called a *touch-me-not* that curls up the leaves when bothered. People guessed it was just an automatic thoughtless reaction. An experimenter dropped 56 of them from a certain height and they all curled up. After a few more drops, less of them bothered curling up. After a while doing these safe drops, they all stopped curling up for the drop completely. But they still would curl up if poked with a stick or something other than dropping them, so they'd learned that specific thing (dropping) could be ignored. The plants remembered this info for a full month from when taught (some insects like bees forget info after only a few days)\n\nAs for deciding where branches would be placed best, plants use different tools to decide the right conditions than we would. Plants have as many as 11 different photoreceptors (light sensors), while the human eye has only 4 kinds of them, so plants can actually analyze sunlight in more complexity than we can. It's like our astronomers use different telescopes to look at things in space in ultraviolet or infrared or other kinds of light we can't see with the naked eye, plants do the same thing in a way. It might be useful for moving their growing branches to the optimal spot for their green food-factories to get the ideal amount of the right colors of light they need to eat (even something like light that's the wrong color can mean worse eating for a plant. Humans care less about color because we don't eat it with photosynthesis. The reason brown algae and a lot of aquatic plants are brown instead of green is because they use a brown dye to eat better underwater because light bends different down there, so being pure green like a tree would actually produce less food)\n\nThe mechanism for plant limbs to go to their best spots is also interesting. There are climbing vines that as they spread, they basically rub their fingertips along the walls and feel different features, then they do things like coil around supports, find certain plants they like to stay tied to and wrap around those plants, move towards the best light sources, etc. Researchers cut the fingertips off of those vines, and after that the vines still grew, but they did it in a much more stupid way, just moving in basically straight lines and not finding the good climb holds and not placing themselves well. It was like the \"brains\" in charge of the movement activity were in the plant's fingertips and not the the rest of the vine's body. I don't know if ordinary tree branches have the same branch-intelligence in their fingertips, it wouldn't surprise me if they did, they'd have millions of years to work on it.",
"Also an added question to this, how/why do trees grow around powerlines? In my city we have powerlines and the tops of the trees have grown in a semi-circle around the lines. It doesn’t look like they’ve been cut, nor have I ever seen them do work to the trees. They just seem to, grow.. around the lines..",
"Duh, they use their eyes and ears?"
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3be8z1 | how will i be affected by the greek bailout refusal? | The extension was refused, so what will the effects be on everyday life? Will products within the eu be more expensive the next coming weeks, or will we get things cheaper since massive amounts of money isn't thrown away? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3be8z1/eli5_how_will_i_be_affected_by_the_greek_bailout/ | {
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1grktb | what does "reality is a social construct" mean? | Since the question is obviously one a 5 year old wouldn't understand, the answer doesn't have to be for a 5 year old.
Hear this idea associated with Marx, Engels, Nietzsche, and Mannheim a lot. What does it mean?? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1grktb/eli5_what_does_reality_is_a_social_construct_mean/ | {
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"If you drop a bunch of strangers on an island, they will begin to adopt certain roles. For example, a Nurturer, a Kid Sister, a Leader, an Outcast, a Planner, etc. People gravitate towards certain roles and then that becomes their identity. It's part of how they see themselves and how others see them. It becomes the accepted reality and it grew only from their intial actions, words, prejudices of each other... social stuff.\n\nNow, what if instead of a desert island we are talking about the entire Earth. A kid is born and grows up knowing that his parents, teachers, police officers are the boss of him and that's his reality. The teacher says jump and he jumps. The kid also learns that he has his own role to play in society. First as son, then friend to his peers, student in school, quarterback on the team, lover, driver, college kid, husband, father, etc. His reality is built from the social roles that he and everyone else engages in. Every morning he wakes up and makes his wife breakfast because that's what a husband does, then he drops the kid off at school because that's what dads do, then he goes to his job because that's what employed people do... his reality is shaped by purely social constructs.\n\nOf course, his reality is also shaped by the laws of the universe, but the purpose of the phrase is to get you to think about how much of your own reality is built only from mutual agreements.\n\nedit: This is what I gleaned from wikipedia, anyway.",
"Everyone perceives everything differently. \n\nKnowing that, reality is simply a universally agreed-upon normal.\n\nIf 90% of people were schizophrenic the 10% of normal people would be considered crazy.",
"Lukemann and Berger are, in sociology anyway, good theoreticians of reality as a social construct. The easiest way to get it is through a reflexion on language: some tribes have no sense of left or right, but only cardinal directions ( East, South,...). From there, you can imagine that the arrow of time is distinctively different in their mind than in yours ( Your arrow of time probably goes from \"left to right\" just like you write). So language builds the frame within which your mind can have fun, but then language is constructed by individuals as well. Let's say I'm Bill Gates, and I build \"Microsoft\". Suddenly, Microsoft becomes a thing, it's an actor within our social life, even if, no one has ever met Microsoft, and never will, it still exists. \n With the thinkers you've mentioned, it is about how superstructures, so the ideological inventions resulting of our history, will define our ethical frame. Our sense of justice in life is build by our social condition. If I'm rich, I believe that I can walk over people because that's the law of nature as I've been told ( and I've been told that by my rich father because that's how we cope with reality, by legitimising it ). It goes both way, you construct reality through your interactions with others, and building a sense to the world as you live it, but you live in this world and are victim of all the social construction that are hidden through language in it. "
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17epib | what's the relationship between beer and root beer? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/17epib/whats_the_relationship_between_beer_and_root_beer/ | {
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"Root beer was originally just beer made from a particular kind of root rather than the grains beer normally comes from. Now, root beer is almost always nonalcoholic, and the root (which we know causes cancer now) is replaced with artificial flavoring."
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4zpasl | how are us state government programs/projects funded? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4zpasl/eli5_how_are_us_state_government_programsprojects/ | {
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"Whew! This is a lot to unpack, as government accounting is kinda a tricky bitch. \n\nYou have a few sources, and these vary by state. Some programs are funded directly by sales taxes (Police, roads, schools, paying for bonds). Sometimes you have a special tax that funds certain things: a 1% gas tax to pay for roads, casino taxes to schools, cigarette tax for hospitals etc... \n\nSome state government functions are funded by charging fees: Parks, Museums, etc.... \n\nSome state government functions are paid for with property taxes: Schools, fire departments, etc... \n\nSome state government functions are paid for with federal monies: Medicare, certain school programs, certain crime prevention programs. \n\nBasically each state is different and determining what goes to what can be tricky. If you're really interested you should look for your states CAFR (comprehensive annual financial report). It probably won't make any sense to you, but if you read enough of them you can start to understand it. Or you could take governmental accounting, however that's usually a junior or senior level accounting class! ",
"The federal and state governments are two separate things. There is a federal Department of Agriculture, but the states also have departments with similar rules that are independent of the federal government.\n\nIn general, state programs are funded by taxes (on sales, income, property, etc.) collected by the state. However, the federal government frequently chooses to fund state programs if the state is willing to follow certain rules. For instance, the federal government gives money to the states to maintain their highways, but only if they keep their drinking age at 21 or above. While the federal government's *authority* in purely domestic matters of a state is strongly limited by the Constitution, it can exercise significant influence in state policy by offering to provide funding.\n\nThe cities receive most of their funding from local taxes as well, but they are not sovereign, unlike the states. City projects may similarly be funded by the state or federal government, as a supplement to their budget."
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3sqizd | how do those reflective emergency body blankets actually keep you warm? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3sqizd/eli5_how_do_those_reflective_emergency_body/ | {
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"You radiate heat away constantly in the infrared spectrum. The reflective blanket, as you might guess, reflects all that right back to your body.",
"It's a trick of physics that the more reflective a material is the less it emits it's own radiation, like heat. The less heat you emit as radiation, the warmer you will stay.\n\n_URL_0_"
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5txzm5 | how did conservative politics come to include more support for police and military. isn't that just inherently more government? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5txzm5/eli5_how_did_conservative_politics_come_to/ | {
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"Conservatives are not necessarily anti-government, they are usually anti-government when it comes to the economy though. Conservatives often support increased police and military spending because they believe police will preserve and enforce the rule of law, and the military will preserve the country, both of which are things that are necessarily implied by being 'conservative' ",
"Law and order is important to conservatives. Maintaining law and order is one of the fundamental functions of government. Conservatives also value in-group loyalty. That means they draw a sharper distinction between \"us\" and \"them\". Defending \"us\" from foreign threats is another fundamental function of government. So the support of police and military could be seen as more government but is consistent with conservative values. Conservatives are not pro anarchy. ",
"The shift happened in the Reagan Administration. Prior to that the second half of the 20th Century was a series of wars started by Democratic Administrations, and ended by Republican ones. Republican President Dwight Eisenhower even gave his farewell speech warning the American people about the dangers of the military industrial complex, a phrase he coined himself. Reagan began a military and nuclear build up, that contributed to the end of the Cold War, but also earned the Republicans a lot of new lobbies in the defense industry that have a stranglehold on the party to this day.",
"There is a distinction between federal/state(local). Military is an increase in federal power (negative for conservatives) but it is used primarily on foreign soil (positive for conservatives). Police (and national guard) are state/local (positive for conservatives).\n\nThis sort of thinking can also be seen with voting, marriage, education, reproductive, health care, and many many other issues. Its not that conservatives don't want big government, they just don't want a big *federal* government telling them they have to allow abortions, or to let gays get married, or stopping them from teaching the Lords Prayer in schools, or gerrymander districts to retain bloc power.\n\n----\n\nThat is one perspective. \n\nAnother perspective is that the Republican party has traditionally been more authoritarian (strong enforcement) and \"tough on crime\" or \"war on drugs\". This view, as with all political generalizations, is growing stronger and eroding the party *simultaneously*. Pro-Trump are currently quite authoritarian, while the libertarian sections of the party are the opposite.",
"In the USA, the end of Jim Crow prompted a political shift to shrink public space (government) as public space and facilities had to be shared with the former slaves. \n\nConservatism in countries outside the USA are different but that is the root of it in this country. ",
"The primary tenants of conservatism are an endorsement of social stability, the preservation of established societal institutions (ranging from things as big as independent courts to as small as the family), and a respect for tradition. Thus, conservatism itself is not inherently anti-government. To the contrary, conservatives endorse a strong -- if limited -- government to provide rule of law, property rights, and general stability. This itself requires a strong police force and military.\n\nAt the same time, conservatism's suspicion of change make it generally against activist government steps -- such as large amounts of redistribution -- that would upend the status quo of society. Thus, conservatives endorse government *to the extent it helps to ensure the status quo* but reject it *to the extent that it would unravel it.*\n\nEDIT -- One final thing I forgot to note originally. Conservatives are not necessarily against *all* social change. However, if change is necessary, conservatism generally believes it should take place slowly and cautiously. ",
"Conservatives use the term \"small government\" as a sort of mass delusion. Basically it's a lie that they just won't admit to themselves. They very much want big government for everyone else, just not themselves personally. They also don't want to pay taxes for the big government that they want for everyone else. \n\nOf all the hypocrises of the traditional conservative mindset, \"small government\" is one of the biggest. "
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41jsxm | why do older generations tend to "double click" everything on computers? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/41jsxm/eli5_why_do_older_generations_tend_to_double/ | {
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"Have you ever gone to open a file on your desktop? Open up a file in your hard drive? All of those require double clicks.\n\nAnd now that I said that, I think you might be referring to then constantly clicking something after the first double click. My suggestion? They're just old and don't realize they already clicked it or they're impatient and tired of waiting. Which is kind of ironic."
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aoe9d3 | why does cracking your knuckles under water seem to amplify the sound it makes? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/aoe9d3/eli5_why_does_cracking_your_knuckles_under_water/ | {
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"When you make a sound, you compress the molecules around into waves. These waves hit your ear, and you perceive it as sound.\n\nAir is a lot less dense than water, so when you create these waves, a lot of the energy is soaked up by the molecules hitting a neighbouring molecule, kind of like kicking a football into another football. \nIn water, because the molecules are so close together, very little energy is released when the molecules bang into eachother as the wave transfers through the liquid. You can demonstrate this high transfer of power with a Newton’s Cradle.\n\nSo to conclude, the water density is higher, meaning the sound and distance a wave can travel is much higher than in air"
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1o6ser | what would happen to the global economy if several asteroids of solid gold crashed into earth effectively increasing the available gold by 100x? | Just Curious what some economists might think would be the effect. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1o6ser/what_would_happen_to_the_global_economy_if/ | {
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"If gold were more abundant, would its value decrease?\n\nI'm not an economist, so I won't speculate how it'd effect the economy... ",
"The world uses fiat currencies. That's money backed up by the government and doesn't have intrinsic value of its own. It's no longer backed up by gold. ",
"These would have to be really big asteroids to have any significant effect on the economy. In that case id think the world would be a bit more concerned about getting slammed by some big asteroids, cause you know millions of deaths and ecological disasters and such. ",
"It wouldn't matter because any meteor large enough to increase the known and speculative amount of gold on earth by 100x would be large enough to cause a mass extinction event."
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2jknw5 | in and of itself, why is sodomy illegal? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2jknw5/eli5_in_and_of_itself_why_is_sodomy_illegal/ | {
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"Moralism in law. It's viewed as sexual deviancy and is legislated against on that basis alone. No practical reasons. ",
"At least in the U.S. it is not illegal. The supreme court ruled that making it illegal violates the right to privacy. _URL_0_"
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bvnmcy | how does the body rid of heavy metals? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bvnmcy/eli5_how_does_the_body_rid_of_heavy_metals/ | {
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"The body *doesn't get rid of them* and that's the problem.\n\nThey cause all kinds of problems because they're poisonous, and the body has no way to get rid of them, so they accumulate in your tissues until you die."
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1wlin9 | the amanda knox appeal | Can anyone give a general rundown on the appeal which has just ended with Amanda Knox being found guilty again? I don't fully understand the Italian court system (who am I kidding, I don't understand it even slightly) and I also don't understand the evidence that was presented. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1wlin9/eli5_the_amanda_knox_appeal/ | {
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"ELI5 Why does anyone care about this case? Do people actually care or is the media just pushing this?",
"I've read a lot of this thread and I'm still quite confused, I thought Amanda was cleared? Why is it happening again?",
"The main thing you need to know about the Italian court system, is that they convicted and jailed scientists for failing to predict an earthquake, which is impossible.\n\nAfter that, just point and laugh. And don't get involved in the Italian Court System.",
"I'd like to add to this discussion that as an american citizen that is currently in America, she is well out of reach by Italian or EU authorities. In the US we have double jeopardy protection so once she has been aquitted and is back on US soil, she can't be accused of the crime a second time. If she is, the US wont recognise the accusation. Italy can have a trial, sentence her to whatever, and demand extradition all they want but the US govt will not extradite her based on the initial aquittal and her double jeopardy protection. \n\nWhether you believe she is guilty or not is irrelevent. Because she is a US citizen and is on US soil, she'll never set foot in a prison cell again for that particular crime. \n\nThe unfortunate side effect of this protection is that she is quite litterally stuck in the US for the rest of her life. If she ever travels to the EU or even any country with friendly extradition laws to Italy or the EU, she would be arrested and sent back to Europe.",
"The top comment has a pretty obvious opinion in it. Is there some more balanced, ELI5 discussion available?",
"Civil Law court system 101:\n\nThere's two levels of courts, the regular court and the appeals court. She was found guilty by the regular court, appealed, and was found not guilty by the appeals court.\n\nThis is where the Court of Cassation comes in. It's not an actual second appeals court, you only appeal to this court when you believe a previous trial was unfair, for example because the judges blatantly misinterpreted the law, because the judges got bribed, that kind of stuff. In this case, it was argued by the prosecutors that the judges wrongly refused to admit certain pieces of evidence, and that the judges misinterpreted the law to mean that there needed to be one single piece of evidence that proved her guilt by itself, while the prosecutors believed the body of evidence as a whole should be considered. The Court of Cassation followed the prosecutors, and declared the trial void.\n\nThis meant that Knox's appeal trial had to be redone (with different judges). They did this, and found her guilty for the second time.",
"This will now serve as the official Amanda Knox discussion thread thing.\n\nAny other related to the subject will be deleted and redirected to this thred.",
"I will add in that from an American perspective, if the scenario had occurred in the United State (questionable crime scene investigation and all) and the conviction was thrown out by an appeals court based on evidence the original criminal case had misconduct by investigators, attorneys (on either side), jurors or the judge, then the ordeal is all over for the defendant. Since the constitution of the US forbids double jeopardy, that is being tried for the same crime twice, someone cannot be retried if an appeals court throws out the initial conviction.\n\nThat brings us to this case where such a verdict had come down from an appeals court, BUT because Italy has no protection against double jeopardy, Italian prosecutors were able to bring up the charges against Knox and Sollecito in a new trial and get them convicted, all over again.\n\nThis of course brings up an interesting legal question: if the charges are certified by Italy's highest court and Italian authorities push for extradition from the US, what would the state department do? That's another ELI5 for another day.",
"The top comment presents an account of events where Ms Knox is entirely innocent, but that is open to doubt. The fact is that a complete mishandling of the case by the Italian authorities makes it difficult to discern one way or another: proper evidence in principle both aids the innocent and condemns the guilty. It is such a shame it's been so badly handled."
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20yui3 | string theory | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/20yui3/eli5_string_theory/ | {
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"I posted this in an askreddit thread once and it seemed pretty well accepted, so I'm copying-pasting it here:\n\nString theory is tricky and largely outside of my realm of knowledge, but I can shed a little light on it. Currently, String Theory is considered one of most likely, if not *the* most likely explanations for... well, everything. In our universe, we have a lot of incredible forces that we take for granted, but don't really understand how they work. Nuclear (strong AND weak), Electric, and Gravitational force. Think about it for a second. If we take a complete vacuum, with absolutely nothing in it, and we place two particles a distance apart, these two particles are going to apply some sort of force to each other. There is no external force being applied here, no slight gust of wind. These two particles just *create* force on each other. String theory tries to explain this phenomenon. It suggests, that if we took any particle in the world (electron, quark, proton, etc) and zoomed really closely in on it with an extremely powerful microscope, what we would actually see is a \"string\", oscillating in different directions. And these oscillations are what give it different properties, be it proton, electron, neutron, etc. And these variations in oscillations are what create the forces. Keep in mind, this hasn't been proven yet, but there is lots of evidence to suggest that it's accurate.\n\nSources:\n\n* _URL_2_\n* _URL_1_\n* _URL_0_\n* And others, but I've closed a lot of my tabs already ;)",
"Elementary particles in quantum mechanics are treated as point particles: they have no dimension. Relativity doesn't work on point particles, but relativity is real. It has real, observable effects, most notably, gravity. So elementary particles can't be point particles.\n\nTo resolve this, string theory treats elementary particles as small, extended strings, so that relativity can work on them.",
"I can recommend the book, but its only _close_ to ELI5....\n\n_URL_0_",
"I posted this somewhere a while back:\n**OVERSIMPLIFIED**\nWe use one set of explanations and laws and rules when dealing with very small things and another set of formulas and explanations when dealing with big things. many physicists take this to mean that we have an incomplete understanding of the universe, and that there is a more detailed explanation out there somewhere that can cover everything. \n\nsort of like how you might use one keychain for home, and another for work, but a person who understands how locks work could just carry around a keychain with lockpicks and open any door.\n\nso there are many explanations and theories that different physicists have come up with to explain how the universe works, and if they are true we could use them to build \"lockpicks\", i.e. that one theory would give us formulas that apply to every situation.\n\nstring theory is one of the most popular \"lockpick\" theories, meaning it is a great explanation for why the universe is how it is (i.e how locks work), and it could give us \"lockpicks\" but it would have to be proven first which it hasn't been. (in the lock metaphor, string theory is a really good explanation of how locks work, we just haven't figured out how to use it to build lockpicks that successfully pick locks yet.) \n\nHope that helped, it is very simple and if you want to know more about the actual contents of string theory read the book or watch the film **the elegant universe** it is made for everyone to understand it is really ELI5 style. \n\n**TLD;DR If physics theories helped us build keys, string theory would help us build lockpicks**\n\n**EDIT: Thanks for my first ever gold, i vow to forever be a better redditor from now on.**\n\n**EDIT** Also, yes I know that i didn't explain squat about what string theory actually says, but I explained why there is so much hype about it, and why it exists, which i think is more important for the average citizen, The actual nuances of string theory are quite hard to ELI5 and Brian Greene does it much better than me.",
"Well, you see, everything is made up of atoms. Atoms are further made up of some weird little things like electrons and quarks. String theory, something that is still not fully understood or accepted, says that these weird little things are all made up of even weirder oscillating things that for whatever reason are called \"strings\", though we have no good reason to think they look like strings. Their are a bunch of ideas about these \"strings\" that try and uniformly explain everything we know to be true, though the theory doesn't necessarily succeed in that. As it stands, someone studying \"String Theory\" is more or less studying the very edge of our knowledge about how the universe works, not necessarily just String Theory, since it's not really a complete Theory with a strong back bone of knowledge supporting it.",
"Bunch little string thingies hold everything together. ",
"String theory is like a popsicle. Its fucking awesome, but too much of it will make your brain hurt.",
"Oh man.. ELI5 string theory..?\n\nImagine an ant crossing an electrical wire. As its walking along this 'tube' shape, it can crawl around it going left or right, until it ends up back in the same spot. He sees the world in a [3d perspective](_URL_0_) (sorry for the shitty paint art).\n\nNow imagine you're in a building, a bit away from the ant on the wire, looking out a window towards him. From your perspective, he can only go in two directions, on a [2d perspective](_URL_1_). This is what it's like for us, who exist in 3 dimensions, to think of the fourth dimension (which strings in string theory are believed to exist in, as well as dozens of other dimensions).\n\nThe theory is that there are .. 'strings' .. smaller than the atomic level (currently the smallest proven object known to exist).\n\nTo get a grasp as to how small that really is: a glass full of water is still 99.99~% empty space. That's how much distance there is between atoms. To see something smaller than an atom is currently beyond our current technological capability.\n\nThere are *many* things in this universe we can *prove*, but cannot understand.\n\nTake for example: a car is in park, with the headlights on. If you measure the speed at which the light is coming out of them, it will be c (299,792,458 m/s, speed of light). This is to be expected.\n\nNow imagine that car is going down the highway at 100m/ph. If you measure the speed at which the light is coming out of the headlights, it will *still* be c. Not c + 100 mp/h, just c. This goes against all of our understandings.\n\nThis being said; here's some more food for thought. Three men are standing on a train cart, going down the train tracks. One is in the middle, one in the front and one at the rear.\n\nThe man in the middle lights a match. Considering the speed of light is constant, no matter what's happening around it, from the perspective of the 3 men the light would appear to reach both the man in the front and the man at the rear at the *exact* same point in time (assuming the men are equal distance from the man in the middle). We can test.. and prove this.\n\nHowever: if you're outside of the train cart looking in, because the cart is moving the man at the front of the cart away from the source of the light and the man at the rear closer to the source, it would appear to reach the man at the rear first. This can also be tested and proven.\n\nSo which does it reach first? Man in the front or man at the rear? The answer is it depends on your perspective of measurement.\n\nYeah. Don't bother trying to wrap your head around it.\n\nIf you're interested in this kind of thing, Brian Greene made 4, one hour long episodes on time, quantum mechanics, and the sort. He does a *very* good job at explaining it in terms the average person can understand. I highly suggest you watch them.",
"This is the best summation I've heard. _URL_0_",
"If you zoom in enough, **all** particles are all made of 1 dimensional strings, they vibrate like a string, and this vibration decides all of its behavior.\n\nPeople forget the theme here is to explain simply and not so wordy",
"Everything is made of music. ",
"I have to upvote this just for the title. You're talking about one of the most bizarre, complex, esoteric subjects that has ever been made up by geniuses. ",
"I had to do an introductory presentation on this a few months ago.\n\nOkay, so there is a problem with our current model of space, specifically general relativity. It is continuous, which means you can see it no matter how far you zoom in. This is bad because at some point the random fluctuations in energy in space make it so that you get miniature black holes everywhere, and it's generally very sad.\n\nString theory fixes this by basically saying that space is not continuous, it is instead quantized (made up of bricks of definite size, not infinitely small size), and all locations in space are snapped to a grid, so to speak. By doing this, you can basically argue that anything under that certain size doesn't matter because it doesn't exist, or something. Poof, magic.\n\nAnd then these structures, called strings, were invented to go inside the space and vibrate in different ways to make all the different particles in the universe.",
"For complex topics like this make a subreddit called /r/ELI15",
"Oh yoi yoi yoi, accelerate the protons! ",
"You are made of atoms. Atoms are made of protons. Protons are made of quarks. Quarks are made of..... the last one is a 1 dimensional vibration. ",
"[Relevant xkcd]( _URL_0_)",
"Not an expert in the field, but I'll give it a shot:\n\nString theory basically thinks that the smallest, most fundamental building block of everything in the Universe is not a particle, but a band of energy. This band of energy makes up protons, neutrons, electrons...and as such everything else. So, with this assumption, you can then quantify things based on these constantly vibrating bands of energy.\n\nWhy does this model exist? Well...to address the Unified Theory. This is the disjoint between our macro scale models of the universe (gravitational forces between planets, etc.) and the micro scale (think quantum mechanics). Right now, our understanding of both are not compatible (thing Lego's and Mega blocks). So by using this string theory, we hope to get new models that can cover both scales and thus describe the physics of everything.",
"Imagine that everything is made of little coiled rubber bands with 10 sides instead of 2. We can only observe 4 of the sides (x, y, z axis and time) , but we think that the other 6 exist because math.\n\n",
"Here is the ELI5 of String Theory.\n\nWe have two sets of rules in our Universe right now. \n\nQuantum Mechanics, which are the rules of the REALLY small things, like things the size of atoms, or smaller. \n\nAnd General Relativity, which are the rules for REALLY big things, like us, and stars, that are affected by Gravity.\n\nBut when you use the rules of General Relativity in the world of the REALLY small, crazy bullshit happens. And when you use Quantum Mechanics in the world of the REALLY big, similar crazy bullshit happens.\n\nSo for now, everybody has just used Quantum Mechanics to deal with small things, and General Relativity to deal with the big things. No big deal, right?\n\nExcept, we don't live in two worlds, we live in one, with big things and small things! So why don't we have one set of rules for everything? \n\nString Theory is our best attempt at making one set of rules for everything. It seems to work so far at combining Quantum Mechanics and General Relativity without crazy bullshit!\n\nThe knock on String Theory, and the reason why we aren't running up and down the street yelling, \"Eureka!\", is because there is no way to test String Theory. To do so, unless somebody comes up with a clever way to do this, we would have to go outside of our Universe, and that may never be possible.\n\nThe wackiest thing String Theory says is that there aren't just three, but TEN dimensions of space, and one of time. But how do we \"touch\" those other dimensions? How do we even know they are there? It's what the math says, but until somebody \"touches\" another dimension, or detects one, it's just math that works, but it's not a \"proven\" reality.\n\nTL;DR We have to two sets of rules in Physics. String Theory is our best shot at making one set of rules so far.",
"reality is made of strings. We only see little bits of them at a time. A ball of yarn isn't socks, but when you arrange it in the right way, then it can become socks. Reality is like that. ",
"To understand string theory you have to understand multidimensional and multiverse ideas.\n\na ten dimensional structure just means its something that is expressed in each dimension. So, a string is something \"vibrating\" cuz that word doesn't really mean anything beyond the 9th interprible space dimension. (Like, wiggle into where? becomes the question that we cant answer yet)\n\nso, real quick to help you think about this, there are 0 through 10 dimensions, where some think, and I think, the 0 and 10th dimension are the same thing viewed from a different reference frame.\n\n0 - the dimension of a point, that containing nothing, but also both negative and positive everything simultaneously \n\n1 - many many many points strung together in one or the other direction to form a line (call this length if you want) \n\n2 - many many lines put side by side on both sides of this line to form a plane (call this direction width if you want) \n\n3 - stack planes both up and down from this plane infinitely (call this depth if you want)\n\n4 - Tricky to get, but, there is a evidence out there that shows that time passes for us in discrete reference frames rather than how we continuously experience it. SO reality happens in \"flashes\" separated in space by the length of a Planck second. Like the points that made up the line back from 0 to 1, a full 3 dimensional reference of space, from tip to tip of the whole universe, stacked one planck second close to each other creates the 4th dimension. Objects in the 4th dimension have their beginning at one end, and their end at their other end. Imagine you at conception and on your deathbed, and every frame of you inbetween being stacked next to its self from every planck second of time. That is your 4th dimensional shape\n\n5 - the probability space of the items in the 4th dimension. So, every possible outcome stacked beside every outcome for everything and every situation.\n\n6 - the infinity that every probabilistic outcome stems from, so, the things that didn't happen because of things that didn't happen forever ago that could have, but our reality didn't observe.\n\n7 - the infinity space, where every point in this space is its own full set of infinity, with a whole universe of possibilities, times, and spaces. There are the different types of realities and infinities that could and \"do\" exist\n\n8 - the different types of different infinities (changing the speed of light v the force of gravity v the energy in the strong force all of these would fundamentally change your infinity and probability space)\n\n9 - the dimension you use to travel infinitely between the different types of different infinities. all space, time, and infinity can be mapped in this dimension. All of it, everything you could ever think of is in this dimension\n\n10 - Once you pack all of everything into a point, you get to 10. This is everything. All of it. And because you cant observe all of it ever, the universe exists here. All the times of the universe that have ever and will ever be, all the outcomes, all of them exist here.\n\nNow, strings are structures in this 10D space that make reality reality. the vibration of these strings in thier dimension, somehow manifests space, the space that time moves through frame by frame, and the energy it holds at different places. All of these things are governed by laws that just work the way they work too.\n\nThe universe and everything is just a mosh of data that represented its self somehow. Its awesome. And some how some way, we as a species became conscious enough to figure all this out.\n\nThis was a response to someone's question, \"Are the strings one dimensional?\" \n\nI think its a nice quick walk through that I made pretty easy to digest",
"Okay Mikey here is string theory. You know how grandma can make pictures out of string right? When she does her needle point? You know how you don't really see the string but you see the picture, Each point looks like a dot of color but it's really made of a string. Now that cloth is a piece of the universe called a brane and how those 'strings' interact with the brane is how we see the universe, just like you see a picture. Now there a various strings we think, and a lot of different cloth, and string theory is an attempt to explain how the picture we see, the universe, really is made. We have two sets of rules that explain how the picture is made depending on how big Grandma's needle work is don,e but you and I know there should only be one real rule how she does it. So String Theory is an attempt to get to the real rules of how that needlepoint is done.",
"_URL_0_\n\nI too was searching for an explanation I could understand. This video was the most in depth and easy to see explanation. I had to rewatch it a few times anyways.",
"String theory is a bunch of different ideas some very serious scientists are thinking about as a way of understanding the world. But instead of using microscopes or building other machines to observe and test these ideas, the scientists use extremely complicated math. \n\nThere are many ways the universe can be described with mathematical formulas. Usually these formulas can be fit together like a jigsaw puzzle; one piece snaps into another and everything makes sense as the picture gradually gets completed. Since a puzzle could have more than one piece that fits a particular hole, scientists like to get confirmation and \"proof\" using experiments to make sure the puzzle pieces are actually the correct ones. \n\nA good example is the news about the Higgs Boson. Many years ago someone named Higgs looked at the puzzle and said something like, \"you know this hole is probably filled with *this* piece, but it could be one of these other pieces, so we should keep working on the puzzle in that area, but one day I predict this piece will finish this entire corner.\" He was right. Everyone cheered. The recent story about gravity waves and the Big Bang is a similar story. \n\nScientists have arrived at a point where we have two sections of the puzzle, each is very beautiful and almost complete. A lot of work went into each section. All of the math formulas for each piece of each section have been tested and verified. In other comments people have called these sections Quantum Theory and Relativity. Sometimes people say these two theories are about 'big things' and 'small things', but those words are sort of misleading. \n\nMost serious scientists that are working on the puzzle are getting very curious. They firmly believe we are really only talking about one puzzle, but that we need a new way to look at the problem other than big and small. \n\nAs I stated above, a portion of these scientists are working on a group of ideas they call String Theory. It's a bunch of different math formulas that *almost* fit together in a way that joins the big sections of puzzle together. \n\nOne of these pieces gives the theory it's name. It says everything we know is made of extremely tiny bits that someone once called 'strings'. The name stuck and is often used. But these bits are not really bits of string. It was just a way to describe something that was almost a 'dot', but just slightly longer. In the math formulas, these 'long dots' (strings) are way, way smaller than what we have tools to measure. In this theory a 'dot' is basically so small it's nothing. If we make it just a little longer it becomes 'something '. Now that it's 'something' we can build things with it in our math formulas.\n\nThese String Theory scientists have been working on these ideas for decades. Their math formulas have become so complicated that computers are required to solve the equations. But using these equations they can describe nearly everything that is needed to join the puzzle sections together. \n\nIn fact, these scientists, using the formulas of String Theory, are even able to describe not just the missing pieces, but many of the existing pieces in the completed sections of puzzle. This makes them very excited and leads them to believe they are on the right track. Their theory not only fills the missing pieces along the edges of the completed sections, it also predicts the shape of many pieces across the entire puzzle. -- *this* is why so many very smart and serious scientists are spending all their time on this work. Their theory is extremely complicated in ways most humans can't understand, --but it requires things we *do* understand to be exactly like they are. \n\nSome of the other famous ideas in String Theory involve reality having 10 (or a different number) dimensions, and the existence of multiple universes, and other far out concepts. These things get talked about a lot because they are so dramatically different than what we think of as normal. But what we think of as normal has changed many times in history. What we know about stars and galaxies and time and space would have been nearly impossible for people to accept 700 years ago. \n\nIt is very, very important to understand that not every scientist is working on the String Theory ideas. Some are working on other ideas to join the puzzle sections. These are all good serious people who are usually making good arguments. Sometimes they sound like they are yelling at each other and calling each other names. But in science there is really only one way to solve these disputes. This is by making, testing and verifying predictions and confirming the world consistently works like your ideas says it does. \n\nOne of the arguments voiced frequently about the ideas of String Theory is that, while it may be a very, very cool and awesome way to make sense of the puzzle, right now it's mostly a bunch of math formulas that we are unable to do real science with. We can't design an experiment to test and confirm whether they are true OR false. This is a point for which the String Theory scientists don't have a good response; at least one that satisfies their critics. But they are very confident they are on to something. They would say they don't have a good response -- *yet*.\n\nEdit: added text: (or a different number)",
"String theory says that everything is made up of very small strings of energy. These strings are what is called \"one dimensional\" like, well, a string. While we can move in three different ways, up and down, side to side, and back and forth, a string can move in ten. \n\nThat is hard to imagine, but we can understand it by analogy. Take a piece of paper and let's pretend for a moment that it is a two dimensional object. You can take the paper and move it up and down, you can shake it, you can even wad it up into a ball. All of that involves *moving* through 3 dimensions. \n\nStrings are like that! They are only one dimension themselves, like a line, but they can move through multiple dimensions. How they move through those dimensions, is thought to be what gives things in the universe their attributes. \n\nAnother analogy might be the strings on a guitar. While they are 'one dimensional' themselves, they can vibrate through three. how they vibrate determines what sort sound they make. Sound, which travels through 3 dimensional space. \n\nSo just like vibrating a guitar string a certain way produces a note we call 'C', vibrating a string theory string a certain way produces a particle we call a 'photon'. ",
"TIL 5 year-olds cannot understand string theory. Neither can reddit.",
"There isn't really an ELI5 for this because the people who work on it don't really understand it either.",
"The *real* explain like you're five answer? Magic.",
"The simplest explanation I've heard is this.\n\n_URL_0_",
"I'm not entirely sure it is possible to give a useful or working explanation of string theory to a 5-year old **or** a layman, because they lack the core concepts, principles, theories and math that *lead* to String Theory in the first place.\n\nAs others have said, the people who study and research string theory at the professional/academic level don't even claim to have a good understanding of it themselves, if only because the core principles of quantum theory that string theory relies on are themselves poorly understood and nigh-impossible to observe directly. It is all *very* *much* **theory**, based on inference: just as if you were standing on a mountain-top at midnight and see lights in the sky, one can assume the ones not moving are stars, and ones that move are *probably* airplanes, but without a tool such as a telescope allowing us to directly observe said lights, informed guesses are the best we can make one what little we can observe. \n\nUnfortunately, the laws and nature of quantum physics makes direct observation of quantum phenomena functionally impossible with the tools we have today. At that level of the ultimately small, we can only measure/observe by directly impinging on the particle in question: when we view something through a typical microscope, we are using lenses to magnify the amount of light reflected back at the eye, light which of course comes from a particular source, either in the room or from the microscope itself. \n\nFor normal objects made of normal atoms, they are bound together with enough force that they either absorb or reflect photons, x-rays, magnetic waves, etc., which can then be viewed by a pair of MKII eyeballs through a lens or on a video screen. However, *quantum* particles are so small, so light-weight (in comparison to big masses of atoms, they are actually, in fact, generally thought to have zero mass) that the simple act of measurement or observation will actually affect the particle directly, because the photon or x-ray, etc., have more energy/mass (E=MC^2) than the quantum object and therefore alter its spin, position or momentum.\n\nAn example: imagine you are blind, and the only way you have to navigate the world is by throwing an endless supply of Nerf balls at things and then listening to see how long they take to hit, and what sound they make. Things like buildings, cars and people won't really be physically affected by a Nerf ball, but any impact will still produce a sound that you can use to determine some things about it: so would a pile of empty soda cans, however if you threw enough balls at a building long enough, it will still be no different when you finish than when you started, but you would eventually get a pretty good idea of its shape, location and distance from you, whereas the pile of empty cans would be knocked over, and the data you got back from it would tell you basically nothing about the shape or configuration of the pile, because your very first act of measurement altered the pile of cans: you know they are there, but almost all information about their previous state was destroyed. The trick in quantum physics then is often to find ways to reconstruct the can pile via reverse engineering from what we did learn in the first pass, or to find ways to observe much more passively.\n\nThis is basically what happens when we attempt to observe something at the quantum level, known as the \"observer effect\" and is *related* to (but not to be confused with) the Heisenberg Uncertainty Principle which states that \"the more precisely the position of some particle is determined, the less precisely its momentum can be known, and vice versa.\" The simple act of measurement in a matter-wave system with light (photons), x-rays, gamma rays, magnetism or what-have-you is enough to disturb the particle's state or states in other ways, and thus limits the amount of information we can determine about a given particle, especially without altering its state. Also tied up in all of this is the [*Schroedinger's* *Cat*](_URL_0_) thought experiment.\n\nBecause we can observe *some* certain phenomena outside the quantum domain that relates, is otherwise affected by, or is a probable effect of, quantum physics (sometimes known as \"the physics of the weird\"), we can make certain predictions and inferences from those observations, along with what we can more directly divine. These observations, along with other observations or theories about the nature of the universe, how matter formed, and how energetic systems interact, when combined, still leave many unanswered questions, and string theory is posited in an attempt to unify these various, often seemingly unrelated, phenomena into a single working model that allows for internal consistency with observed results.\n\nString theory, in particular, relies on the presence of a multidimensional universe above and beyond the length, width, height and time that most of recognize, where so-called [\"point particles\"](_URL_2_), instead of being zero-dimensional points of pure energy, might instead be one-dimensional \"strings\" of energy, whose various quantum states give rise to the various \"elementary particles\" whose existence we are able to predict, but whose origins and nature are extremely difficult to observe or describe with any certainty or consistency. It might help to think of such a \"one dimensional\" object as being very similar to a silver-foil \"laser\" hologram, which - while only being two-dimensional - can appear to have depth in addition to length and width.\n\nThe goal, being, that with a strong model framework whose internals bear up to testing and scrutiny, other observations and predictions about the externals may be made to help shed light on such questions, in much the same way that an engineer might look at an incomplete blueprint and still be able to divine where plumbing will have to run, where rooms will be situated, where power-outlets will go, etc.\n\nFinally, from [Wikipedia](_URL_1_):\n\n\"Many theoretical physicists (among them Stephen Hawking, Edward Witten, and Juan Maldacena) believe that string theory is a step towards the correct fundamental description of nature. This is because string theory allows for the consistent combination of quantum field theory and general relativity, agrees with general insights in quantum gravity such as the holographic principle and black hole thermodynamics, and because it has passed many non-trivial checks of its internal consistency. According to Hawking in particular, \"M-theory is the only candidate for a complete theory of the universe.\"[4] Other physicists, such as Richard Feynman,[5][6] Roger Penrose,[7] and Sheldon Lee Glashow,[8] have criticized string theory for not providing novel experimental predictions at accessible energy scales and say that it is a failure as a theory of everything.\"\n\nI know that the above still doesn't *really* explain String Theory, however the whole subject is too deep and complex to convey adequately in a single post (or even a hundred posts) on a site like this, but I hope I've given you enough background information to clear up some of the principles involved and allow you to make sense of further reading on your own.",
"Where's Morgan Freeman when you need him? He could be earning freckles like crazy in here.",
"If we need to get 'outside' our universe to see if string theory is legit, we can always ask Jane for a ride. ",
"If there is one thing that I'd think cannot be ELI:d, it's the string theory.",
"If you think you understand string theory, you don't understand string theory.",
"Loop Quantum Gravity says that String Theory can suck it."
]
} | []
| []
| [
[
"http://superstringtheory.com/index.html",
"http://www.nuclecu.unam.mx/~alberto/physics/string.html",
"http://theory.tifr.res.in/~mukhi/Physics/string.html"
],
[],
[
"http://www.amazon.com/String-Theory-Dummies-Andrew-Zimmerman/dp/047046724X/ref=sr_1_1?ie=UTF8&qid=1395379544&sr=8-1&keywords=string+theory+for+dummies"
],
[],
[],
[],
[],
[
"http://i.imgur.com/fIXlIkv.png",
"http://i.imgur.com/qtj2LlJ.png"
],
[
"http://xkcd.com/171/"
],
[],
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[],
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[
"http://xkcd.com/171/"
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"http://youtu.be/p4Gotl9vRGs"
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[],
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[],
[
"http://xkcd.com/171/"
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"https://en.wikipedia.org/wiki/Schr%C3%B6dinger%27s_cat",
"https://en.wikipedia.org/wiki/String_theory",
"https://en.wikipedia.org/wiki/Point_particle"
],
[],
[],
[],
[],
[]
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64av8q | why does the heat in death valley c.a. stay only there? | Why is it localised to that area. What keeps all of C.A. from boiling like it does there? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/64av8q/eli5_why_does_the_heat_in_death_valley_ca_stay/ | {
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"Death Valley, in particular, is in a deep basin from which air has a hard time escaping. So, it tends to sit there and just get heated up hotter and hotter by the sun's rays.\n\nAir is a pretty good heat insulator. Heat doesn't move through it very fast.",
"There are other parts of California that get quite hot, California's Central Valley in particular has a basin like Death Valley's that traps heat in, however Death Valley is farther South, below Sea level, and in the middle of a desert."
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3097il | why didn't the british get involved in the american civil war? | Just wondering | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3097il/eli5_why_didnt_the_british_get_involved_in_the/ | {
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"It was a tough call for them. \n\nOn the one hand, the British Empire outlawed slavery in the 1770s - many of the southern Founding Fathers supported independence to protect the institution of slavery from British law. They had already proclaimed slavery a crime against God, and were attacking slave ships leaving the Ivory Coast. Ending the institution in America would have made a lot of moral sense.\n\nOn the other hand, if the US separated it would weaken them as a power - the last war to defend Canada was firm in their minds, it'd been costly, and if the US became two nations it would be much easier to defend Canada moving forward. A US conquered by confederates would have been easier to diplomatically isolate. Geopolitically, it suited British interests to have America become a failed state.",
"By the time of the civil war Canada was on its way to being Canada - an independent state that had obvious and public ties to the United Kingdom, but self-ruling internally. Something a bit more than a colony but a bit less than an entirely sovereign nation. During the civil war the [Charlottetown Conference](_URL_0_) was planned and eventually held to try and work out the details of the so-called confederation of a new Canadian state. \n\nAt this time the UK supported all this because they had some time since given up on the new world as a source of great wealth or anything, and it was just a burden on them to have to be so involved in the day-to-day operation of the now-provinces. They figured that an independent Canada would still be plenty friendly and open to trade, but less a burden on their government.\n\nSo the UK already wrote the new world off, and the future Canadians were already fairly involved in trying to work out the political difficulties of confederating. Bringing the Anglophone protestants and French catholics was already a huge effort and a bit of an involved process, so it'd be a bitch and a half to go back to the drawing board and try to bring any of the USA into the fold.\n\nJust letting the USA fail, or not, was really easy and unlikely to have any negative effect on the UK or Canada.\n\nDuring confederation it was made a priority of the new Canadian state to establish a railroad across the continent to the Pacific ocean and establish settlement all along the now-border to prevent any more expansion by the USA north, and that was enough for the UK and Canadians to be content. \n\nAlso quite importantly the war of 1812 ended with the Treaty of Ghent that basically said: \"We're tired, let's not do this.\" and both sides agreed to just go back to as it was. Both the UK/colonials and the USA were previously established as being willing to more or less live and let live at Ghent.\n\n**TL;DR:** Canada was busy becoming Canada, the UK was busy not caring about the new world anymore and the previously established peace seemed reasonable.",
"The North made it very clear that the civil war was an internal matter and that if Britain (or France) was to recognize the Confederate States as an independent nation that it would most likely lead to war with Britain.\n\nBritain did rely on cotton imports from the Confederate States, it wasn't willing to risk a war over it and realized it could get cotton from elsewhere.",
"Depends on what you mean by 'get involved'. If you're asking for the British to attack the North (US), the better question would be why? Did you see the numbers of men and supplies the US churned out during the war? They were already a substantial industrial power. Even if you thought highly of the British Empire during this time, armed intervention was guaranteed to be bloody, and all for a questionable cause (supporting a slave state).",
"Generally speaking foreign countries try not to get involved in civil wars because backing the losing side has disastrous diplomatic consequences, and it's very difficult to justify participation to your population. \n\nThough there were tentative trade agreements and the like between the US and the UK, relations were still strained enough for the british to not throw their weight behind the north.\n\nThe confederacy did try and get europe involved by stopping the shipment of cotton, thinking this would created a huge economic incentive to support it in Europe. This was a miscalculation. At best it prevented European powers from supporting the union, but this effect was subtle at best. For the most part Europe had a 'meh!' reaction, as cotton was not all that critical to their economy.\n\nIt was also the very definition of lose-lose for *any* foreign power to intervene. Neither side of the war was willing to be annexed in exchange for help. Dealing with two trade partners instead of one caused no issues to diplomats and merchants, not enough to intervene anyway. And involvement by any foreign power on either side would have been seen as a major breach of sovereignty by the other side, and would have made relations difficult to impossible.\n\nFinally: the official reason for the war wasn't slavery, it was state's rights. Slavery played a huge role in causing the federal government to encroach in states rights, but it wasn't the only reason. Neither side was saying they would cut ties to Europe if they won, so why would a foreign power get involved in an internal political dispute?\n\nAdd to this: Warfare underwent *major* changes through the Civil war. Armored ships, rail logistics, trench warfare, rifled muskets, repeating rifles... All saw they first major uses in the american civil war. Some caused *huge* losses and casualties to one or both sides. Structured charges on prepared enemy positions were now absolutely murderous affairs, and European powers saw this. They understood that they would need to commit huge troops, at frightful force depletion rates, in return for... not that much really. \n\nPerhaps they could have thrown money the union or confederate's way? Well, the union wouldn't have accepted it as the need wasn't that great and they wouldn't have agreed to the conditions imposed on such an offer. The south may have accepted towards the end of the war but by then the north clearly had the upper hand and it wouldn't have made sense diplomatically to support the south unless money was back with huge numbers of troops.\n\nMaybe launch a full scale invasion of the entire colony? That would only have (probably) resulted in an end of civil hostilities as union and confederacy ally themselves to face this new threat. It would not have been an easy victory for any European power. Again: the US military due to many factors including conflicts in western border states and territories was large an experienced, well funded, well equipped. Certainly much more so than during the revolution. And a british invasion would have probably brought other powers, france and germany, to bear against it.\n\nAnd here's the final thing: at this point in time the US is not the main economic or military force of the planet, it's in Europe. Any invasion of the new world would have immediately triggered a number of treaty agreements between European powers and would have triggered a full scale European war. Britain, who had by then figured out how to build an empire with through the clever use of flags, simply didn't feel the costs in diplomatic, political, economical and military material was worth the gains of interfering in an internal US conflict.\n\n",
"Foreign recognition of the Confederacy was critical for the South. That's why Abraham Lincoln went to great lengths to keep other nations out of it.\n\nSlavery was outlawed in the British Empire so while they wanted southern cotton they had serious reservations about about siding with the Confederacy because of it. Lincoln could have assured Europe would stay out of it by saying the Civil War as about slavery but that would have made a lot of people in the North balk about supporting the war effort and he needed both.\n\nOnce it looked like he could include slavery as a reason for the war he had to wait until the tide had turned for the North, otherwise it would have looked like desperate pandering to get Europe to side with the North.\n\nThat's one of the reasons Gettysburg was a critical a victory as it was. It gave the Union credibility when it said it was committed to ending slavery in the South.",
"They had no good reason to. Around this time they were getting cotton from India and Egypt, so why help the losing south? And they were industrialized and had no need for northern good, plus the North was pretty just the expected victor anyway."
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bc30bg | how/why do your eyes stabilize when you move your head? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bc30bg/eli5_howwhy_do_your_eyes_stabilize_when_you_move/ | {
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"The nerves that control the muscles in the eye receive information from the vestibular system (one that senses your position in space)\n\nSo when you turn your head left, the neurons in the left vestibular system fires to a nerve called the abducens nerve that directs the right eye to move right. Abducens then sends a signal to the left side to tell the left eye to move right as well."
]
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||
ciut3v | how are national surveys such as pew research so accurate, especially since they interview only a few thousand people? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ciut3v/elif_how_are_national_surveys_such_as_pew/ | {
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"Statistics is a branch of mathematics that addresses questions like this. Put simply, if you choose a representative sample from a much larger population, the opinions on the sample group align tightly with the opinions of the entire population. It comes down to two things. The first is that none of us is special or unique - there are literally millions and millions of people who think about any given issue the way you do. So if you are part of a sample group, you speak for a big piece of the entire population. Second, the polling company needs to make sure the sample group isn't homogeneous - in other words, there needs to be differences in the sample that reflect the population you want to draw conclusions about. If the larger population is 55% women, then your sample should be 55% women. If the population is 20% between 18 and 29 years old, your sample should be 20% be between 18 and 29. Etc. Good polling firms interested in reliable and meaningful results know how to craft a representative sample.\n\n/edited to correct typo",
"When you take a sample that can be subdivided the same way as the larger population (let's say, X% of each race, gender split, lgbt representation, income brackets, etc), there is a mathematical model for how confident you are in your statistics based on the ratio of your sample size to the population size.\n\nLet's say you had 95% confidence. That means if you repeated the survey 19 more times, with the same representation, only 1 of those would have significantly different results.\n\nSo if you have something with 95% confidence, that actually means nothing, because it can be the one study out of 20 that is way off. However, once people start replicating the study, you can validate the data."
]
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3x6jll | how is an area of a country/city is calculated? | How do Wikipedia, Google, etc come up with those numbers? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3x6jll/eli5_how_is_an_area_of_a_countrycity_is_calculated/ | {
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"text": [
"The boundaries of both countries and cities are usually fairly well defined. It's what keeps surveyors employed. Once you know where the boundary of the city or country is then it's just one more math problem to calculate how much land.\n"
]
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|
7cyku3 | since people with higher metabolisms are turning more energy stores into usable energy, do they have more energy? | Confused about this | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7cyku3/eli5_since_people_with_higher_metabolisms_are/ | {
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"text": [
"There's a lot of confusion evident in this question.\n\nFirst of all, you're using the word \"energy\" in two different ways. \"Energy stores\" and \"usable energy\" both use the word in the same way, i.e., chemical energy generated by the body from food. This can be either direct from the gut to your cells, or be stored in the form of fat for later use. Either way, you're still breaking down chemicals derived from food you've eaten. But in the phrase \"do they have more energy,\" we're talking about something else entirely. A person's subjective sense of \"feeling energetic\" is not at *all* the same thing as chemical energy taken from food. \n\nSecond, the idea that some people have \"higher\" or \"lower\" metabolisms is technically true, but not particularly *helpful*. A person's \"basal metabolic rate\" is the rate at which their body consumes chemical energy when at rest. In other words, the amount of energy you consume *just staying alive*. The issue here is that while muscle tissue consumes energy at a faster rate than \"adipose\" tissue (fat), a person with more *tissue* may well have a higher BMR than a person with less. So a morbidly obese man weighing 400 pounds is going to have a higher BMR than an Olympic athlete weighing 165 pounds, simply because there's *so much more* of him. Yes, muscle consumes more energy than fat, but not so much more that it can offset an extra few hundred pounds. So knowing a person's BMR, by itself, doesn't really tell you anything useful unless you also know their sex, height, and weight. Even then, it's not all that useful a statistic, as it doesn't vary all *that* much from person to person when you control for those other factors. \n\nThird, what people most mean when they talk about having a \"fast metabolism\" usually has more to do with how efficient the body is at extracting chemical energy from the food you eat *and* how efficient it is at storing that energy as fat. So it may seem as if *this* person can eat 5,000 calories a day and never gain an ounce of weight, while *that* person gains five pounds if he even *looks* at a cheeseburger. . . and we're really not all that sure why. Hormones definitely play a role, but exactly which hormones play what role, and how, is still being studied. Some people's bodies are just a lot better at those things than others. Genetics, age, sex, and physical activity all play a role (e.g., a lot of people find they start to gain weight around age 30), but again, those roles are not all that well understood. The micro-biome in your gut probably does too. But what's going on isn't really about \"turning more energy stores into usable energy\" nearly as much as getting chemical energy out of food in the first place and then storing it for later use. "
]
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df7ofm | how do they make eye glasses for infants? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/df7ofm/eli5_how_do_they_make_eye_glasses_for_infants/ | {
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"I saw a post on Reddit today, looked like less than a year old",
"At just a few weeks old, a baby with healthy eyes will track you, moving their head and eyes to follow you. If your baby isn't doing this significantly later than most babies exhibit this behavior, they may have eye problems. The optometrist may then use a machine to get more information about the eye and determine what kind of prescription is needed. It would likely have to be updated fairly frequently as the baby's eyes develop, but it could lead to allowing a baby born with moderate vision problems to see more clearly.",
"I assume you're asking how the refractive error is measured. The old school way is to use a retinoscope and neutralize the refractive error with lenses. This gives you a decent measure of the prescription without the patient having to do anything. Autorefractors do basically the same thing, but are kind of hard to use with little kids.",
"You temporarily paralyse the eye’s ability to change focus with special drops (cycloplegia), then you use an autorefractor to determine any optical imperfection in the eye (basically bounces a beam of light off the retina and back to the machine). This tells you the ‘strength’ of the lens required to correct the optical imperfections of the eye. This can be performed under anaesthesia if required. It is quite accurate."
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