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3g8gf5 | why is the usa's bmi distribution so different to that of japans? (10x as many obese people) | According the the WHO:
BMI|Japan (%) |USA (%)|
:--|:--|:--|
Underweight ( < 18.5)|11.1|2.3|
Normal (18.5-24.99)|66.4|34.3|
Overweight (25.0-29.99)|19.6|30.9|
Obese ( > =30)|3.0|32.5|
[Source](_URL_0_)
Why is it so different? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3g8gf5/eli5_why_is_the_usas_bmi_distribution_so/ | {
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"Diet and portion control. Americans eat tons of shit, processed food in huge quantities. It is disgusting.",
"In America, you have to go to a special overpriced hippy grocery store to find bread without high fructose corn syrup and most areas are set up so you have to own a car.",
"Diet. The Japanese diet tends to be rich in oils and good fats from things like fish and other seafood. This, combined with the base of many dishes being simple foods like rice or vegetables makes for an overall healthy diet. It's not that junk food doesn't exist in Japan, and the Japanese are really good at making really good junk food. It's just that it's not a big part of their diet.\n\nAmerican diets, conversely, are rich in sugar and sugar supplements. Everything you look at that didn't come directly from the ground is likely to have added sugar. Couple that with American's always on-the-go attitude and it gives rise to people eating a lot of fast food, which has very little nutrition, or processed food, which can often suffer the same problem. Put those two things together, oversimplifying a little, and you have an obesity epidemic.\n\nThere are bigger things in play like the economic status of poor individuals and marketing designed to misinform but mostly, American food tends to be sugar, salt, and too much fat.",
"Japanese eat different foods than Americans. Their food is also typically much more filling so there is not that urge to overeat. Japanese tend to have high protein/vegetable diets. Where Americans just have high grain/sugar diets. Another thing is Japanese food is typically very low in sugar. I tried some Japanese candy once and it was barely sweet, so I felt no craving to eat more. "
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bfz0uy | how two different dnas don't mix during blood transfusion causing a person to change biologically due to different genes? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bfz0uy/eli5_how_two_different_dnas_dont_mix_during_blood/ | {
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"A couple of reasons. First among them is that red blood cells don't contain DNA. Shocker, right? So when the blood is separated out for transfusion it is unlikely someone would be getting much DNA in the first place.\n\nAnother huge reason is that cells are self-contained packages. They tend to keep their DNA inside themselves and don't take in any free-floating DNA nearby. It is sort of like how driving down a street your car doesn't just mix up and trade engine parts with the other cars on the road, it isn't really something that can happen. So not only is the donor blood not going to be releasing DNA, both in that cells don't just throw it around and because they didn't have it to start with, the cells of the receiving body aren't going to be taking it in.",
"DNA doesn't mix easily just because two cells touch each other.\n\nIt takes a lot more than that to mix DNA.\n\nThat's why you don't become spiderman after touching a spider."
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68vwzo | why is there no market for transportation that fits between a normal city car and a motorcycle? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/68vwzo/eli5_why_is_there_no_market_for_transportation/ | {
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"Smart cars not small enough for you?",
"Smart Cars seem to do well in my city, and they fit that bill.\n\nSpeculation: part of the reason there's not a major \"in between\" category is that as soon as you go up a little bit in size, you lose **a lot** of the motorcycle perks. Motorcycle's two-wheeled body is very fuel efficient, and can squeeze between lanes... as soon as you go four-wheeled you lose those advantages. Storage, too: I have plenty of neighbors who can squeeze their car AND a cycle into their parking spot, but good luck getting anything four wheeled in there. Thus, because a small car means you have to \"fit\" in a big car world *anyway,* you might as well get some extra seats and some amenities and have a proper vehicle.",
"There are a lot of vehicles that fit your description, minus the 50 mph max speed. VW Bugs, MINI Coopers, Smart Cars, Fiat 500s, etc. \n\nA lot of subcompact cars have 4 seats instead of 2 because adding the extra seats doesn't decrease efficiency that much and most people prefer having the extra seats for when they need them.\n\nCars also don't max out at 50 mph because placing that restriction on them wouldn't be very helpful. It's not much more expensive or inefficient to make an engine capable of going at least slightly faster. It's also safer to allow drivers to speed up if they have to in case they need to pass someone, get to the hospital in an emergency, etc. Also, 50 would be a weird cutoff since many highways in the city allow you to exceed that speed.",
"Pick any two: Big enough, fuel efficient, or cheap. \n\nI think most people are going to opt for \"big enough to accomplish what I need in a given day\". So if you're a family with two working parents and kid(s), you're going to want 2 cars that are both large enough to hold the kids and friends/groceries/luggage/sports equipment. \n\nYou could also ask yourself why trucks are so popular. The majority of the time, the beds are empty. People buy them because either they like the look, they like being up high, or they like the *option* to tow or carry large items. \n\nI'd be really interested in an [Elio](_URL_0_) at some point. There's at least a little bit of a market, as 65,000 people have reservations. They are cheap and small and have good gas mileage. It would make a great second car. But if we have kids, I'd need something that could tote them around in case I was unable to switch cars. ",
"I found it too wasteful as well, so now I'm using an electric unicycle to commute. 5km's each way and it's faster than driving in the rushhours. ",
"There is: it's called Uber. Or Lyft or [insert rideshare service]. \n\n > It struck me how wasteful it is, that I carry around 840kg of metal just to transport 70kg of me 30 miles, every day.\n\nThe problem with cars isn't their size, because you need that size when you need to move multiple people. The problem with cars is that you don't know when or how you will need to use them, so they are bigger than necessary for many uses and, worse, they _sit unused_ most of the day. You spend 30-45 minutes driving to and from work. The rest of your day, the car sits unused. \n\nThe solution is not smaller vehicles. The solution is moving away from the concept that each individual needs a _dedicated_ vehicle. \n\nIn the past, the challenge to this has been that the most efficient way to get a vehicle _when you need it_ has been to own a dedicated vehicle, and one that is large enough for your most common needs. You may only have one person in it when commuting to work, but taking the family of five to the park on Saturday requires all the seats. \n\nTechnology will solve that in two ways: \n\n1. By dispatch technology that can match the person needing transport with the nearest available appropriate vehicle of the appropriate size to transport them. This is what Uber/Lyft/etc are _close_ to doing today, but they're still stuck with repurposing existing dedicated-vehicles to this purpose. \n\n2. By driverless technology that makes the matching of rider and vehicle not dependent on the needs of a human driver. Driverless technology also has the advantage of being more efficient, i.e. vehicles in dedicated-driverless lanes can all be communicating with one another, which will allow them to drive just a foot or two apart like a train, and slow down or accelerate all at once. \n\nEver been in a long line of cars at a red light, the light turns green, then the first car accelerates, then the second, then the third, and so on, until by the time the car in front of you accelerates, the light has turned red again? Driverless cars don't have to behave like that because they could be in constant communication -- the light turns green, they _all_ move forward at the same time with the same acceleration. Matter of fact, if you can get human drivers off the road entirely, you don't even need stoplights (at least not for vehicular traffic -- you still need them for human pedestrians).\n\nSuch technology reduces the overall number of cars on the road. In this scenario, cars might even become bigger and more luxurious, because the primary reason cars have been shrinking in size over the last 50-70 years is to reduce weight to reduce fuel consumption, which is only a problem because of the dedicated-vehicle model. \n\nEDIT: a couple edits to clarify and correct grammar. ",
"There is. It's called the [Renault Twizy](_URL_0_); it's not a car, it's not a motorcycle.\n\nIt's a *quadricycle* - electric powered with a range of about 60km, windows and doors an optional extra"
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5fqk5t | why aren't large, passive, whales eaten alive by sharks or other ocean predators? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5fqk5t/eli5_why_arent_large_passive_whales_eaten_alive/ | {
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"Because they're not placid, pacifist creatures. They aren't going to just sit there while a shark chews on their fins. They're going to fight for their survival, just like any other creature in the world. And most whales are easily large enough and strong enough to fend off a few sharks, especially considering they travel in groups and can defend each other as well as themselves.",
"That tail of theirs is powerful, if it damn well pleased it would crush you with that alone. Also one bite ain't gonna do shit, and the whale will go after a threat. Also remember whales are almost entirely social with large groups. \n\nIt's usually wise in the animal kingdom to not fuck with animals 10 times your size. There are plenty of easier targets. That said smaller whales and sharks will often go after the children of the whales if they are isolated.",
"Huge and lumbering *is* a defense. There's a lot of power behind every movement a blue whale makes. That said, it *can* be killed by predators, there's a video out there somewhere of an orca pod working cooperatively to hunt one. ",
"Whales are not passive and defenseless. They're huge, intelligent animals capable of incredible strength and speed. A great white shark weighs ~2000 lbs whereas an adult blue whale weights up to 300,000 lbs. A shark is simply not capable of inflicting any meaningful damage on something that weighs 150 times what it does. Imagine a rat trying to kill an adult human. \n\nWhales are powerful predators in their own right. Orcas have been known to kill and eat great white sharks. Sperm whales eat giant squid. Large whales can only be defeated with teamwork, which sharks are not capable of. Orcas, which are much more intelligent, have the skills necessary to kill large whales. "
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xzr2h | why are political ads allowed to say things that are outright untrue? | With the election getting ever closer, campaign ads are popping up on the internet almost constantly. A lot of these ads are simply untrue. This Obama ad (_URL_0_), for example, claims that Romney is against abortion including in cases of rape and incest when the bill they cite explicitly says that rape and incest are excepted. This Romeny ad (_URL_1_) says that Obama wants to gut welfare, which is untrue because he simply wants to make funding more flexible on a state level. And then there's quotes that are taken out of context, including the infamous "You didn't build that" Obama quote (_URL_2_).
My understanding is that if a company makes a lie about their product they can be sued by either customers or the FDA (I'm not 100% sure about that though). Why isn't that logic extended to political entities? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/xzr2h/eli5_why_are_political_ads_allowed_to_say_things/ | {
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"It's going to sound cliched, but the answer is Freedom of Speech. That gives people the right to say almost anything. Political speech has historically been given even more leeway than other forms of speech because there's the biggest risk of abuse if the government or courts were going to try and regulate it. The last thing you would want is the party in power using laws to try and stifle their opponents speech.\n\nThe end result is that you can say things that just aren't true. This is the price we pay for making sure that people can say whatever they want.\n\nP.S. To address the question about companies lying about their products. That's considered commercial speech and has generally been given less protection than other forms of speech. The Federal Trade Commission (FTC, not FDA) can step in if they think the public is being harmed by deceptive advertising.",
"The thing is nothing that they say in these ads are 100% untrue. They are simply true in the right kind of interpretation of their words. In a way Obama making welfare flexible at the state level would be gutting the current welfare system just like Romney's ads featuring the \"you didn't build that\" quote out of context are technically true but leave out part of the story. Ultimately politicians specialize in half truths and answering the questions they want asked rather than the questions that are asked of them and that shows in their speeches and ads.",
"1. Most of these claims have enough technical true in them that they are not outright lies\n2. Freedom of speech protects you from saying untrue things, so long as they aren't willfully and maliciously untrue. While some of these ads look that way, that is a very high standard to prove in court.\n3. What good would suing do? Some candidates have sued, but it typically makes them look like crybabies and hurts them politically. Winning will just get you a little money, it won't make you president."
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60fo8x | why are some metric prefixes like deca-, hecto-, kilo-, symbolized with lowercase letters, yet others (mega-, giga-, etc.) by uppercase letters? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/60fo8x/eli5_why_are_some_metric_prefixes_like_deca_hecto/ | {
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"It's just a convention. Mili is a small m (miligram = mg), Mega is a big M (Mg = megagram), so that there is no confusion. The powers of 10 over 10^6 are all capital letters. Big numbers. Big letters. It's user friendly. ;)\n\n[Here](_URL_0_) is a table where you can see the letters in action.\n",
"When the metric system was created in Revolutionary France, they didn't anticipate needing very large or very small prefixes. So they created prefixes that change by a factor of 10, all of them with lowercase symbols:\n\n* milli (m)\n* centi (c)\n* deci (d)\n* --\n* deca (da)\n* hecto (h)\n* kilo (k)\n* myria (my)\n\nWith time, the use of the metric system progressed, and it was adopted by scientists, who then started realizing just this range going from 10^-3 to 10^4 was too small. Also, it was clumsy to have lots of prefixes with just a factor of 10 between them.\n\nSo at a later point (1960) new prefixes were created, changing at a factor of 1000: mega, giga and tera on the big side, along with micro, nano and pico on the small side. The decision to use uppercase letters for big prefixes and lowercase for small prefixes is probably due to uppercase letters simply being bigger (also, the 1960 prefixes themselves are etymologically related to words for \"big\" or \"small\" as appropriate).\n\nThen, as new prefixes were added in 1964 (femto, atto), 1975 (peta, exa) and 1991 (yocto, zepto, zetta and yotta), the convention of lowercase for small and uppercase for large was maintained, and the latest additions have the convenient property that \"inverse\" prefixes (like 10^21 and 10^-21) use the same letter."
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6yh5py | if producing a music video for a song helps to greatly increase its popularity, why don’t artists make music videos for almost all songs in their albums? | Is it due to financial matters? Or purposefully choosing only one song to be popular? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6yh5py/eli5_if_producing_a_music_video_for_a_song_helps/ | {
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2oda0i | how do countries with "free" health insurance compare to the us, is cost equal considering the additional taxes they might pay? | To my understanding many countries with free health insurance have higher income taxes and sales taxes. In the US I pay some money to medicare out of my paycheck, I have a monthly premium, and a deductible.
Are the overall prices comparable to each other if I needed care or is the US getting screwed? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2oda0i/eli5_how_do_countries_with_free_health_insurance/ | {
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"Our system is so inefficient that we already collect the tax dollars necessary to run a canadian, swedish or british-style health system. \n\nFederal healthcare spending in the united states is higher than almost any nation in the world. [Source](_URL_0_). Of the big OECD countries, only Netherlands, Denmark, France, Austria, Germany, New Zealand and Japan spend more tax dollars on healthcare, and only marginally more at that.\n\nPeople who don't study this stuff blame the wrong sources. Pharma. Defensive medicine/tort law/etc. Physician salaries. Greedy hospitals. The real underlying reason we're so inefficient is almost entirely due to how we finance healthcare. Having an insurance market that consists of both private and public payers has created some EXTREMELY bad incentives and a ton of overhead costs. \n\nBasically, because hospitals/providers make so much more on commercial insurance than government insurance, they tailor all their business strategies around this fact. Efficiency improvements might lower your costs by 5%, but expanding your services to gain negotiating power with commercial payers might let you raise your prices by 30% or more. There have been studies done that show prices going up an average of 40% when a hospital market transitions from one with lots of competing hospitals down to one with only one or two large hospital systems. Sadly, quality of care suffers along with it. \n\nTake away the incentive to price gouge private insurers by fixing prices at a single medicare price, and costs go WAY down. Maryland does this for hospital based services. Back in the 1970's, MD spent more on hospitalization per capita than any other state. Then they implemented a system that fixed rates uniformly across both public and private insurance. Now they're the cheapest (or at least very close to it).",
"The US is getting screwed. Healthcare in the UK is far cheaper for being socialised, having the profit removed and generating economies of scale.",
"I used to live in Australia, which has a publicly funded, universal healthcare system also called Medicare and is funded by the \"Medicare Levy,\" and income tax surcharge of 1.5%. This surcharge is means tested, meaning that is you fall in a lower income bracket you pay less or even nothing. (Additionally, if you fall in a higher tax bracket AND do not have private health care, the surcharge is a little higher. The idea is that if you can afforde private cover, you should have it).\n\nHow much you end up paying on the levy is going to be difference depending on your circumstances but, as an example, a family with 2 kids with the husband making $80k and the wife working part-time earning $30k will pay approx $100 p/month. (80k of taxable income, the 30k falls in the low-income bracket and is excluded from the surcharge. 1.5% x 80k = $1200).\n\nIn that system, all general doctor visits are fully reimbursable. Specialist doctor visits are 85% reimbursed where you pay 15% up to a (low) cap.\n\nTo give you my own personal experience. I have 4 kids aged between 9 & 3. Did not pay a cent for any of the pre-natal care, ultrasounds, or difficulties. When they were born, we received outstanding doctor care for free. We took them to the GP for all their followup appointments, immunizations, and random sicknesses. Did not pay a cent for any of it. If we needed antibiotics, they were subsidized. \n\nThe system isn't perfect by any means. And we are a pretty healthy family and try to avoid heading into the Doc, but with kids this age, it happens. Knowing that I could head down to my local doc, at any time for any reason, and receive a high level of care and not go bankrupt because of it gave us a huge level of peace of mind. Cost me less than $100 a month.\n\n(I've now been living in the US for the last 2 years. Current health insurance for my family plus medicare is ~$400 a month.)",
"Heathcare costs are incredibly complicated, so it's really hard to compare because the level and availability of treatment will vary wildly.\n\nThat said, the US fails miserably in terms of the amount of money we spend on healthcare when compared to a number of modern, western healthcare systems. [Here is a somewhat recent chart](_URL_1_) showing the percent of a nation's GDP it spends on healthcare. In 2012, the US spent 17.9% of its GDP on healthcare. Compare that to universal \"free\" health insurance (i.e. tax-funded) countries do. \n\n* United States 17.9% of GDP spent on healthcare\n\n* Canada 10.9%\n\n* Germany spends 11.3%\n\n* France 11.7%\n\n* United Kingdom 9.4%\n\n* Sweden 9.6%\n\n* New Zealand 10.3%\n\n* Australia 9.1%\n\nAgain, this is not a perfect comparison because just what equals healthcare coverage varies. My guess is in the US the high end of healthcare coverage beats out most but the low end (particularly for the uninsured) compares quite poorly. Another way to look at this is actually by [GDP per capita.](_URL_0_) That was a percentage of total GDP, but to figure out how efficient we're being you should look at it on a per capita basis to try and figure out how much money we're spending for coverage per person (regardless of whether health insurance actually covers everyone). Those figures are below.\n\n* United States GDP per capita - $53,143 x 17.9% = $9,512.60 per person\n\n* Canada - $51,958 x 10.9% = $5,663.42\n\n* Germany - $45,058 x 11.3% = $5,091.55\n\n* France - $41,421 x 11.7% = $4,846.25\n\n* United Kingdom - $39,337 x 9.4% = $3,697.67\n\n* Sweden - $58,269 x 9.6% = $5,593.82\n\n* New Zealand - $41,556 x 10.3% = $4,280.26\n\n* Australia - $67,468 x 9.1% = $6,139.58\n\nSo one of the costs that other people have mentioned is administration. In some countries like France I believe, doctors post the costs of their top 100 common procedures... kind of like a Burger King. You can't do that in the US because each of those procedures might cost a dozen wildly different prices based on the type of insurance the person has. Because of this you have to spend a fair amount on just having staff responsible for figuring out the complicated billing procedures and back-and-forth with insurance companies. There are many reason that the statistics are the way they are, and I'll bet some of the health expenditures might involve money we spend on great research in the US (which is a good thing), but it is safe to say the system we have is incredibly inefficient in terms of money spent.",
"The U.S. spends more on health insurance than any other developed nation, spends more on taxes on health insurance than any country but one, and has significantly poorer outcomes. We are being shafted.",
"No one mentions the mandatory hospital suppliers. They charge hospitals absurd mark ups which these hospitals have to recover through over charging procedures. Which then charges insurance companies more to the consumers",
"\nProbably a minor point, but one thing Canada's system gets right is negotiating deals wih drug companies, so our costs are substantially lower in that regard. ",
"Just my perspective:\n\n\nI'm a Canadian making 60k a year before taxes. My take home pay every 2 weeks is roughly 1400, but the deductions are building me a handsome pension, ridiculously good health care (I have $1500 per year just to spend on massages), pretty much unlimited dental, eye-care, medication, you name it. So even though my husband and I both suffer from severe mental health issues and need regular medication, doctors visits, meetings with psychologists and other medical care we don't ever have to think or worry about it.\n\n\nLikewise, my mother has severe crohnes disease (sp?) and her treatment costs $3000 a month, but she only pays the $12 dispensing fee for the actual medication.\n\n\nWe do pay a lot of taxes, but in my view it's more than worth it. Without our health care my husband and I would be living in poverty, miserable and unable to cope with the challenges we are faced with. ",
"The US is getting screwed.\n\nIf you compare to other wealthy countries (Northern/western europe, Canada, Australia and Japan) the US is paying about 18% of GDP for healthcare, and ends up with worse care than people paying 10-12%. \n\nGovernment spending on healthcare is the odd one. In the US remember there's medicare, medicaid, federal and state employee insurance and veterans affairs (and probably others). The combined cost of those programmes in the US is close to enough to run the UK NHS - which at 9.4% of GDP is probably the most cost effective healthcare system in the world for some of the best care. Or at least was until Cameron and Osborne had at it. If it ain't broke those idiots will find a way to break it. \n\nComparing federal spending isn't a good idea. In canada we have a mix of responsibility between the federal and provincial governments, so quite a lot of that cost is not on the federal balance sheet, it's still government taxes though. The UK doesn't really have provinces at all, though scotland and northern ireland and wales sort of are, the vast majority of the country isn't, so for them it's all federal spending. France and Germany have departments and states respectively, etc. \n\n_URL_0_\n\nHave a look at that and think for a minute about the UK versus say, France. 9.4% of GDP vs 11.6. France is spending almost 25% more on healthcare than the UK... and they both have pretty comparable quality of care overall (any less than the UK and you're tending to look at worse care, or city states). But the US is spending 17.7% of GDP - 88% more than the UK... and the UK system is actually better, and provides care to everyone in the UK. There's a lot of degree of choice and what you want to pay for, in france you can call a doctor to your house the same way you can a plumber, and in France you get prescriptions very readily, so the french are paying more for services they want which, on the whole don't get them a lot of direct medical benefit, but if that's what they want they get it. \n\nThe US is/was living in a fantasy land of healthcare costs. Obamacare isn't going to cure everything wrong, but it's basically a copy of the swiss system, which manages 11% of GDP for very good care for everyone. ",
"The U.S. spends more money per capita on healthcare than a typical socialized-healthcare country.\n\nThere are a number of different reasons for these cost differences, and they manifest in a number of different areas.\n\nThere are lots of reasons: \n\nHospitals charge extremely high rates for some services which are only purchased in urgent situations (where comparison shopping is just not viable). This is a very big cause of the gap.\n\nIn the U.S., medical care costs have been very opaque (and billing both opaque and inaccurate) for some time. Even when it would be feasible to do prior research to rule out providers that overcharge excessively, the lack of price transparency has made this difficult. \n\nUntil quite recently, patients have not paid a large enough fraction of the cost for them to care about price transparency -- especially with fixed-dollar copayments having been the norm for most common healthcare needs until quite recently. As a result, there has been little demand for price transparency. This is improving gradually in the last few years, as costs have finally skyrocketed so far that even insurance that pays 90% of the cost leaves patients owing enough to care about finding a good price.\n\nIn the U.S., we don't really have a \"healthcare system\" -- we have a variety of market participants in various roles. (This is changing, as ObamaCare is leading to a huge consolidation and a move toward managed care). As a result, both quality and price vary widely across the board. The best care in the world is available in the U.S. at extraordinarily high prices. Decent care is available at higher-than-average prices, and poor care is available at modest prices. If you have the money to pay, there's nowhere on earth that you can go and get better treatment. This drives up per-capita costs because the rich spend a ton of their money buying amazing life-saving and life-improving care. That's just statistical noise though, since people who quote per-capita spending usually are really interested in what a typical person spends. (A typical American does spend a lot more than the equivalent costs elsewhere, but not by nearly as much as the statistics suggest)\n\nOver the past couple of years with ObamaCare coming along is increasing this stratification, with small private practices going out of business -- the market is splitting in to \"concierge\" care for the rich and corporate managed care for the rest, as everybody in between is squeezed out of the market.",
"I am happy to pay the higher tax, knowing that if I am ever ill, have an accident or need serious, expensive surgery, I won't have to think twice about the cost of saving my life. No life should have a price on it and it's sad that so many can't afford decent healthcare. ",
"Taxes are usually (always?) progressive, so whether or not the prices are comparable has a lot to do with how much you make, and how much healthcare you consume. \n\nIf you make a lot, and use very little, you're better in the USA. If you make only a little, but use a lot, then you're better in Canada/Europe/etc.\n",
"Considering I had a large scale braces operation done. (surgical removal of 3 teeth just below my nose + braces for 3 years. Taken off then reattached for another year) for free. \nIt's hard not to be happy to pay the higher taxes. \nOnly thing that grinds my gears about the Danish taxes. Is the absolutely moronic 180% tax on cars. It doesn't make the government more money. It forces people to keep their old clunkers. Etc etc. ",
"the places with public healthcare that i've seen usually have a mechanism to keep costs in check. Just based on that, Americans get fucked in the ass hard.",
"Centrally funded health is way way cheaper than the US. Even in Germany with a superficially similar system to the US. \n\nMost of the time the government is responsible for agreeing prices. They have a lot of negotiating strength, being a monopoly. But there's also a lot of difference in the way health care is approached. In Europe, health is not considered something that should be for-profit at all. We accept that at times it's necessary to have free market providers but not that their profit should be the maximum the market can bear. \n"
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65elug | whilst vs. while | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/65elug/eli5_whilst_vs_while/ | {
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"While both words mean the same thing, there is usually a time element in the connotation of whilst. \"Bob was relaxing with a book whilst flying at 30,000 feet.\" The \"while-same-time\" mnemonic helps you remember the difference.",
"Zero difference at all in meaning. If you're in America, just say \"while\" or you'll sound a bit snobby."
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[],
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mmp2v | why are interest rates at rock bottom for savings accounts and most other types of investments but my student loans rates are mostly above 6.5%? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/mmp2v/why_are_interest_rates_at_rock_bottom_for_savings/ | {
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"And for that matter, why doesn't the government offer student loans at prime rate? They can't be discharged, so any defaults are *already* backstopped by the taxpayer. What better investment than funding all educational endeavors at the minimum cost? \n \nI realize the answer is probably *corrupt greedy assholes*, but if there's a technical reason I'm missing, I'd love to hear it. ",
"Probably because of high levels of student loan defaults. Higher risk = higher interest rates.",
"What you just stumbled on to is the basis of our banking system. It is called 'fractional reserve banking' _URL_0_\n\nI am going to slimpify the numbers here, in reality the bank has to keep a certain % of their deposits on hand. but the basic concept is this. You depost $100 in a bank the bank pays you 1% interest on your savings, so at the end of the year you've made $1 in interest. However they didn't just leave your money sitting in the vault. They took your $100 and loaned it to me as a personal loan at 10% interest. So when I paid them back at the end of the year I paid them $110, my original loan plus $10 in interest. The bank has now made a $9 profit off your deposit. That's how banks make a large piece of their profits. \n\n(and yes I realize that the interest calculations would actually be compounded i'm making an illustration here not providing financial planning)",
"Interest is the cost of a loan. Basically the price is driven by how badly the debtor needs the money now. So as for banks, since the Fed rate is incredibly low, getting money from an individual isn't that terribly valuable. This means they can set interest rates low, and if that discourages X amount of people from depositing, for now it's fine. But for a student, who desperately needs the money, it's important enough to take out a loan that the price is driven very high. \n\nJust treat it like any other supply/demand thing. Imagine we're on a desert island and the bank owns an orchard of pineapple trees and you're trying to barter with your own pineapple tree. The bank just has less value for being given money now than you do, so they can afford to not pay a high price.",
"And for that matter, why doesn't the government offer student loans at prime rate? They can't be discharged, so any defaults are *already* backstopped by the taxpayer. What better investment than funding all educational endeavors at the minimum cost? \n \nI realize the answer is probably *corrupt greedy assholes*, but if there's a technical reason I'm missing, I'd love to hear it. ",
"Probably because of high levels of student loan defaults. Higher risk = higher interest rates.",
"What you just stumbled on to is the basis of our banking system. It is called 'fractional reserve banking' _URL_0_\n\nI am going to slimpify the numbers here, in reality the bank has to keep a certain % of their deposits on hand. but the basic concept is this. You depost $100 in a bank the bank pays you 1% interest on your savings, so at the end of the year you've made $1 in interest. However they didn't just leave your money sitting in the vault. They took your $100 and loaned it to me as a personal loan at 10% interest. So when I paid them back at the end of the year I paid them $110, my original loan plus $10 in interest. The bank has now made a $9 profit off your deposit. That's how banks make a large piece of their profits. \n\n(and yes I realize that the interest calculations would actually be compounded i'm making an illustration here not providing financial planning)",
"Interest is the cost of a loan. Basically the price is driven by how badly the debtor needs the money now. So as for banks, since the Fed rate is incredibly low, getting money from an individual isn't that terribly valuable. This means they can set interest rates low, and if that discourages X amount of people from depositing, for now it's fine. But for a student, who desperately needs the money, it's important enough to take out a loan that the price is driven very high. \n\nJust treat it like any other supply/demand thing. Imagine we're on a desert island and the bank owns an orchard of pineapple trees and you're trying to barter with your own pineapple tree. The bank just has less value for being given money now than you do, so they can afford to not pay a high price."
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8rwdpm | when global corporations lose a lawsuit and are required to pay millions of dollars, where does that money go? | I recently saw American airlines was required to pay $45 million to settle a lawsuit on price fixing. I can’t find anywhere that says who or what gets that $45 million. Southwest recently had a similar scenario. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8rwdpm/eli5_when_global_corporations_lose_a_lawsuit_and/ | {
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"A lot of these are class-action lawsuits which *basically* means a large group of people who were hurt by some action are suing the company for damages. So they get the money.\n\nSometimes the government also is fining the company, such as the case with the VW cheating scandal that involved, in the US, $25bn in fines and damages combined.",
"It depends on wether it is a suit by the government that results in a fine or one by people who were wronged by the company who are awarded money.\n\nOften it is large groups of wronged people who have to share the money (after the lawyers got their cut).\n\nRecently VW was fined a very large sum. They were sued by the German state of Lower-Saxony which is where they have their corporate headquarters so the money goes to that state. (Which is ironic since the same state is also a major shareholder of VW.)"
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2i5zhp | how do space suits work? | In regards to pressure. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2i5zhp/eli5_how_do_space_suits_work/ | {
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"The suits have a rubberized layer inside that essentially acts just like a balloon. It is a pure oxygen atmosphere inside, which allows the pressure to be much lower (4.7 psi) than normal sea level pressure on earth (about 14.7 psi). It needs to be low pressure otherwise the astronauts would find it almost impossible to bend their limbs.\n\nThe low pressure is also why it takes sometime for them to get ready for a spacewalk. The pressure aboard the ISS is pretty much the same as earth, ~14.7 psi, so the astronauts needs to do breathing exercises to prepare for the low pressure 100% oxygen suit."
]
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|
20tn6e | why is the crimea vote seen as illegal by the g7 but the future vote about scotland is not? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/20tn6e/eli5_why_is_the_crimea_vote_seen_as_illegal_by/ | {
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"Physical violence. Scots aren't being physically threatened, and the rest of the nation approved the vote could happen.\n\nThe Scottish vote will be free, open, and fair. Nothing about the vote in Crimea meets any of those requirements.",
"The controlling country approved, that difference is a big reason. Although there are many more criticisms of the Crimean vote (like it being done while being occupied by the power which would annex the area holding the vote).",
"Because hypothetically, a vote in Scotland for independence will actually include options aside from \"Yes / Yes\" and wouldn't have people having votes counted more than once.",
"It's not that there is some kind of international legal principle that parts of countries can't ever hold a referendum for independence. It's more that like any vote, it needs to be conducted in a free, fair, and open manner, so that everyone involved can agree with the outcome, whether it went their way or not.\n\nSome differences between the Scottish referendum and the Crimean:\n\n* The UK Parliament has approved the Scottish Referendum (in fact an [Act of Parliament](_URL_0_) was required to be passed before it could even go ahead). In Crimea the Ukrainian Government has not approved such a vote -- and regardless of whether or not the current Ukrainian Government is considered legitimate, its predecessor (Yanukovich's Government) had also not approved such a referendum\n* The Scottish referendum will be taking place following over a year of build-up, allowing all groups involved to argue their case both for and against. The Crimean referendum took about a fortnight between announcement and vote, during a time of major political upheaval. It's highly unlikely that all involved groups were able to put their views across to the voters in a fair and regulated manner.\n* There are no armed men on the streets of Scotland threatening violence against people who look like they'll be voting against independence. It was widely reported that various armed groups were intimidating known opponents of independence such as Tatars in Crimea."
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1wgzh1 | sf warp speed and how don't they hit planets/comets etc. when using it? | Pretty much what title says.
What is Warp Speed? Is it like a worm hole? If it's actually going the whole distance without worm holes, how come they don't hit anything? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1wgzh1/eli5sf_warp_speed_and_how_dont_they_hit/ | {
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"It depends, a lot, on which SciFi universe you're talking about. \n\nMany use some kind of alternate dimension (hyperspace, jump space, etc.), in which case you just use normal techniques in the alternate space. This is the Babylon 5/Warhammer 40,000/Star Control solution. \n\nSome use a point-to-point jump (Battlestat Galactica, Event Horizon, EVE) in which case there's nothing to hit. \n\nSome do weird things to normal space to allow higher speed (Star Trek) and just drive around obstacles normally. "
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1ns67u | how do they do it in movies when they show really old pictures of a character? | For example, I was just watching The Office when Jim showed an old (~10 years) picture of him and Dwight. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1ns67u/eli5_how_do_they_do_it_in_movies_when_they_show/ | {
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"text": [
"Sometimes they use makeup on the actor to make them appear younger, other times they use another actor - sometimes, they make up the actor's son or daughter to look more like their parent (sometimes, no makeup is required), still other times they will use a picture of the actor as a child, and photoshop the background, clothes and props to suit.",
"They usually use an actor who looks similar. Source: I work in the film industry. ",
"Photoshop. Old photos. Make up. Etc. It's fairly easy. ",
"In some cases it's done purely with Photoshop. This obviously isn't the best scenario, sometimes the older ways of makeup or actor doubles aare actually the most effective. If I wasn't on my mobile I'd show you a terrific example of bad photoshop from Cloud Atlas, but you may have to wait until I get home!"
]
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3w98nf | where does the money go when i pay for a money order? | Let's say I go to USPS and purchase a money order. It seems to me that the money goes to USPS, because that's where I'm purchasing it.
Then the payee goes to their bank to cash out. The bank gives the payee the amount on the money order. All is well.
But what is happening to the money throughout all of this? How does it get from the place of purchase to the place that gives you the money if they are different places? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3w98nf/eli5_where_does_the_money_go_when_i_pay_for_a/ | {
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"text": [
"Money orders contain the account information for an account accessible by the company or institution from which you purchased it. This account is where the money goes when you buy the money order. So when cashed in, the bank can withdraw the money from their account.",
"A money order is a bank-confirmed permission slip to withdraw a certain amount from your account. You put the name of the recipient and give them the money order, they can take it to their bank, and that bank gives it to YOUR bank, and they transfer the money over."
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fqitrn | why do glass and ceramics break when you drop them, while plastics and metals don’t? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fqitrn/eli5_why_do_glass_and_ceramics_break_when_you/ | {
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"Glass and ceramics are brittle \n\nThey dont deform instead they respond to pressure or force by breaking\n\nWhile plastics and metals can bend and arent broken so easily\n\nAs to why that happens is something to do with their structure. Maybe someone else can help you out on that i dont know much about that",
"Ceramics have a rigid crystal structure. They cannot take much/any strain before breaking apart, there is no ‘give’ within the material itself (ability for layers to slide over each other without breaking apart entirely). Breaking Strain is a physical property of a material - the extension (before breaking) divided by the length under test. Ceramics also invariably have surface imperfections which are the source of crack propagation, if for example you knock the material it might shatter (at the speed of sound). \n\nPlastics are made up from tangled chains of C based molecules, which can slip and slide over each other while maintaining structural strength, within limits of course. \n\nMetals too are ductile (opposite of brittle) - gold can be drawn to atomic thicknesses, according to Wikipedia, which is a great source of information for questions like this."
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5s51e5 | why do people with a stutter typically only have trouble with the first syllable of a word? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5s51e5/eli5_why_do_people_with_a_stutter_typically_only/ | {
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"text": [
"I suffered with a stutter. I was deaf until I was seven. The stutter isn't a problem of starting, it's a problem with fluidity. This problem just happens to show up at the git-go. "
]
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[]
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||
1x7dr2 | why don't the oceans absorb into the planet? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1x7dr2/eli5_why_dont_the_oceans_absorb_into_the_planet/ | {
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"text": [
"Its either at its saturation point (cant absorb anymore) wont absorb into things like solid rock or it is too hot probably"
]
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||
516w9m | why do games and software in general load fast if you've recently used them, but load slower if you haven't used them in a while? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/516w9m/eli5why_do_games_and_software_in_general_load/ | {
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"text": [
"Cache.\n\nModern operating systems keep data in memory until it has to make room for something else and/or use the hard drive's internal cache to store data that it recognizes as being used commonly."
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||
58zgsw | what would the us have to do to revert back to a no political party system? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/58zgsw/eli5_what_would_the_us_have_to_do_to_revert_back/ | {
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"There is no way. Political parties are not part of the government. They are a group of like-minded people who decided the best way to get what they want is to unite behind a single nominee. Political parties are a natural result of our freedom to assemble. Dissolving them would be a violation of the First Amendment. Even if we did dissolve them, people would just make parties again, unless we somehow made it illegal to meet with others, discuss politics, and agree on stuff. \n\nIf we did that, it's not really the US anymore so no, there's no way."
]
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4zly3h | why did connecting to dial up internet sound like a robot being tortured | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4zly3h/eli5why_did_connecting_to_dial_up_internet_sound/ | {
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" > seriously what was that\n\nThat was the actual data being transferred over the phone line. The modem converted data into sound, and played the sound over the phone line for the other computer's modem to listen to and convert back into binary data.\n\nSpecifically, the part you heard was the \"handshake\", where the two modems at either end negotiated things like maximum data rate. After the handshake was complete, the modem would turn off the external speaker. But if you could listen on on the phone line, you'd hear the same types of noise constantly as data was being transmitted or received.",
"It wasn't actually necessary to hear it - pretty much every modem let you turn the sounds off, but no one ever did. I'm guessing for three reasons:\n\n* Most people probably didn't know you could\n\n* Some people probably wanted them on to make sure it was working\n\n* Everyone got so used to it that they didn't even really notice after a while\n\nBut that's what \"noise\" sounds like when it's played through a speaker - if you were to hook up your TV's signal to a speaker somehow, it would probably sound similar. Vocal and/or musical sounds going through a line work the same way, it's just that since they're understandable, it doesn't sound horrific as Internet traffic does."
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7nuq0g | the key characteristics and differences between euclidean and non-euclidean geometry | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7nuq0g/eli5_the_key_characteristics_and_differences/ | {
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"The key factor is the parallel postulate, or more generally: given a line and a point not on that line, how many lines through that point are there that are parallel to the original line? In Euclidean geometry, the answer is always 1. In other geometries, this isn't the case. The most common answers are \"0\" (spherical geometry) and \"infinitely many\" (hyperbolic geometry). ",
"Euclidean geometry for the most part assumes you are drawing your shapes on something like a sheet of paper on a table. That table and paper might be infinite in size, but in general you expect certain things to happen or not happen when you draw your shape no matter where you draw your shape on that paper.\n\nFor example if you draw a triangle in Euclidean geometry then the measure of all the angles will add up to 180 degrees.\n\nBut there is no reason that paper need be flat. Anything we do to the paper to make it not flat is Non-Euclidean geometry. You could for instance roll it into a tube and tape the edges. Now you have very similar rules but things play out a bit difference. Now for example you can draw a line in one direction and depending on what direction you pick perhaps it goes on for infinity like before. Or perhaps if you pick another direction it goes around your loop and reconnects with its self forming a circle. Pick somewhere in between those and the line spirals around the paper endlessly.\n\nNormally in everyday life we use Euclidean geometry. If we were in a city with a bunch of square blocks all the same size, you could solve things like 'If I go 3 blocks north, and then 4 blocks east, how many blocks would I have traveled had I just gone in a straight line from my start location to my end location.' Answer - '5 blocks.'\n\nBut the earth isn't a flat sheet of paper (much to the disappointment of the Flat Earthers) and is more like a sphere than a piece of paper.\n\nSo you can do things like 'I'm at some point and I walk 5 miles south, I then turn 90 degrees. I then walk some distance in a straight line. I then turn 90 degrees in the other direction and walk 5 miles north. I am now back at my starting location. Where am I?' Answer? There are many such locations on earth! The most commonly known location is the North Pole.\n\nEDIT: Some people are pointing out that part of my explanation is incorrect. I'm not going to change it though, as the basic point is to demonstrate that a flat surface behaves differently than non-flat surfaces. Sure Mathematicians might have a very well defined view of flat surfaces, but often well defined math principles aren't easy to express in an ELI5 perfectly. So I'll accept that I'm wrong about cylinder, but leave the analogy as it really is intended to be just a quick primer into getting your mind thinking in a non-euclidean way.",
"To expand on the other answer, there are 5 main postulates in euclidean geometry which are built upon to create the theorems you learn about and prove in high school geometry.\n\nNon euclidean geometry is the same, but with a different set of starting postulates.\n\nIt can also refer to geometries such as taxicab geometry (and variations), origami geometry (might just be the name our teacher called it, but was focused on what constructions you could make by folding paper), and many other crazy geometries.",
"I go south for 10 miles, west for 10 miles, and north for 10 miles. And I end up back in the same place. Where am I?\n\nWell, i'm in non-euclidean space, because in Euclidean space that's impossible. I must be on the surface of a globe or something where a lot of the regular rules of geometry you'd expect don't quite apply. \n\nNon-euclidean geometry is geometry where your space must be weird, or bent, or wraps around on itself, or something to make it different than an infinite, flat surface, where the rules of infinite, flat surfaces don't hold up.",
"There are two ways you can imagine that - from a purely mathematical point of view and from a real-life point of view.\n\nFrom the real-life point of view, Euclidean geometry assumes we work with a flat surface. Non-Euclidean geometries do not assume that. Some types of Non-Euclidean geometries do assume other things - for example, that we work with a curved surface. If we assume something about that curvature, than we can come out with some useful rules about those curved surfaces. If we do not assume anything - we can just understand how geometry works in general. Based on that understanding we could imagine some weird\ncrazy curvatured surfaces. And to our surprise, we found out that some physics could be explained more elegantly if we use that crazy math instead of usual Euclidean geometry.\n\nFrom pure math - Euclidean geometry based on 5 main postulates. We just assume they are true and prove everything else. Those postulates are quite basic - like you can always draw one and only one straight line between 2 points. Some scientist tried to simplify that - what happens if we replace those 5 with other 5? Or with other 4? or less?\nAnd they come out that you can. It is easy to replace those 5 postulates with different specific sets of other postulates - then initial postulates will be proved with help of new ones, and everything will remain the same. So to keep Euclidean geometry we can formulate 5 postulates in different ways. We come up with simplest definitions, but we could easily think other 5 postulates which result in equivalent geometry.\nBut not any 5 postulates. It came out, that if we take different sets of postulates and we'll get different geometry. There is a whole branch of math dedicated to that postulates study. There is a lot of different useful stuff you can come up with if you assume something, or do not assume anything but basic.",
"Euclidean geometry is a bunch of characteristics that Euclid observed about geometry from drawing lines on paper. Those characteristics are called \"axioms\" nowadays, or \"assumptions\" - they're things that you assume are true in order to work something out when doing mathematics. These assumptions are basically all really obvious things like, \"if you have two points you can connect them with a straight line\" and \"if you have a straight line segment you can extend it forever in either direction\" and things like this.\n\nThere's then the question of whether those assumptions actually hold in the real world. If you set up any situation in which they're all true, then you've got a situation which is Euclidean. If you set one up where one or more are false, it's non-Euclidean. So there's only *one* way in which geometry can be Euclidean, but several in which it can be non-Euclidean.\n\nOther answers explain some of these possibilities but always on a sphere. Imagine for an alternative how geometry might look on a pringle. In fact let's make it a gigantic space-pringle. You can still connect points with lines on a pringle, of course, and if it's big enough you can extend points as far as you like. But something else is weird: if you take a point and a straight line on a pringle (now, you have to know what a straight line on a curved surface is, but suffice to say you can come up with something sensible) then there are lots of lines through the point that never touch the first line. In contrast if you do this on a flat piece of paper there is exactly one line that doesn't touch the first one - the parallel line going through the point.\n\nSo one way of being non-Euclidean is to be like a pringle.\n\nAnother aspect of geometry is how distances are calculated: in Euclidean geometry this is Pythagoras' Theorem; you add up the squares of the distances along each axis and take the square root. You can change this *metric* - way of calculating distance - to, for example, the Manhattan Metric (the distance from A to B is just the same of the distances along each axis - so if you were travelling on a grid like the streets of Manhattan, the distance you have to travel is the number of blocks North or South, plus the number East or West - you can't take a shortcut diagonally). This is another non-Euclidean geometry.",
"Other commenters have correctly pointed out that geometry on a sphere has different properties from Euclidean space, and it is therefore \"non-Euclidean.\" This used to confuse me because \"non-Euclidean geometry\" wasn't discovered until the 19th century, whereas spherical geometry was understood for quite a long time before that. What I eventually discovered is that there is a point of confusion in the way the word \"non-Euclidean\" is used.\n\nIn modern days, mathematicians have a very expansive view of what we mean by geometry. When we talk about any sort of geometry in which we can measure lengths of curves and the angles between them, this is called [Riemannian geometry](_URL_0_). This is sort of our default concept of geometry, and it includes spherical geometry as well as all sorts of other geometries (such as a bumpy sphere), most of which are not Euclidean.\n\nHowever, *classically*, \"non-Euclidean geometry\" meant something very specific. It meant a theory which satisfies all of Euclid's postulates (concerning points, lines, distances, angles) *except* for the so-called Parallel Postulate. In this sense, the sphere does not count as \"non-Euclidean geometry.\" (Specifically, one of Euclid's postulates is that lines can only intersect once, whereas lines on the sphere will intersect twice.)\n\nThere is essentially only one \"non-Euclidean geometry\" in this sense, and nowadays we call it hyperbolic space.\n\nOkay, so now I can answer the original question: What's the difference between Euclidean space and hyperbolic space? Well, there is one key difference, which is that the Parallel Postulate holds in one but not the other. That is, given a line and a point not on that line, in the Euclidean plane, there is always *exactly* one line through that point that does not intersect the given line (i.e. one parallel line). In the hyperbolic plane, there are always infinitely many such lines. This may seem weird, but it just requires re-imagining what you mean by \"line.\" [See here](_URL_1_) for a visualization.\n\nOne basic consequences of this is: In the Euclidean plane, the angles of a triangle have to add up to 180, whereas in the hyperbolic plane, the angles always add up to some number less than 180. (In fact, the sum is determined by the area!)\n\nUnlike the sphere, the hyperbolic plane is tricky because it does not \"sit inside\" 3-space nicely. (The link I gave above lets you visualize how the lines intersect, but the distances and angles get distorted.) However, you can understand hyperbolic geometry by analogy with spherical geometry: If two ants depart from a common point on a sphere with a right angle between them, you'll notice that the distance between them is always *smaller* than it would be if those same ants had done the same thing on a Euclidean plane. In contrast, in the hyperbolic plane, the distance between them will always be *larger*.",
"Its all about the how much things curve. If you draw shapes like triangles and squares on a flat sheet of paper they will look a certain way (with triangles, the interior angles add up to 180 degrees for example). However if you are drawing on a curved surface things might look different. For example if we draw shapes on a balloon, lines that are straight look like they bend, and we get a rounded looking shape (for triangles, the angles add up to more than 180 degrees). \n\nThis is the same thing that makes intercontinental flights look like they curve and go way too far north when in fact the flight path is actually a straight line, the shortest distance between the two points. ",
"Euclidean Geometry is done on a flat piece of paper.\n\nNon-Euclidean Geometry is done everywhere else.",
"There's already lots of good answers, but here's a very simple way to look at it:\n\nThe ancient view of geometry, known to/invented by the Greeks over 2 thousand years ago, successfully created a mathematics of 2D shapes like triangles and circles and straight lines, and how to derive answers to nearly any question about such things based purely on 5 starting assumptions (\"axioms\" or \"postulates\") plus logic.\n\nThis was carefully written down by Euclid, and the result has therefore been called Euclidean Geometry ever since.\n\nThis system was trying to answer questions about shapes on a flat 2D surface, like a flat sheet of paper without anything like pre-existing grid lines.\n\nIt did not try to deal with numbers at all, although the Greeks were good at arithmetic -- that was simply a different subject to them.\n\n(Numbers and algebra and geometry were all connected and combined eventually, but that's a different topic)\n\n\"Non-Euclidean Geometry\" really got going strong in the 1800s, and it was about considering different questions, such as, what about changing or altering one or more of the 5 starting axioms, like \"what about shapes on the surface of a sphere instead of on a flat piece of paper?\"\n\nThe geometry of the surface of a sphere turns out to be intimately connected to questions of how to navigate ships at sea far from land, so that particular non-Euclidean geometry can easily be seen to have potentially important practical applications.\n\nIt turns out that many kinds of geometries can be created by varying or deleting or replacing any of the 5 axioms of Euclidean Geometry.\n\nPick any kind of 2D \"surface\" (or \"space\" for 3 or more dimensions), define how flat or curved it is, pick the number of dimensions you want (2D, 3D, 4D, 24D, infinite-dimensional), and other such things, and define it carefully and formally, and there is a non-Euclidean geometry that corresponds to the logic of the shapes that are possible on that surface.\n\nA sphere, like the approximate shape of the Earth, has somewhat different geometric rules than those for flat geometry, and a doughnut-shape (\"torus\") that is sort of like a sphere but has a hole in the middle, has yet another somewhat different set of rules for figures on *its* surface.\n\nA very, very large number of kinds of non-Euclidean geometries have been discovered or invented that are either interesting/useful in their own right (\"pure math\"), or have important applications to technology (\"applied math\"), or both.\n\nEinstein's General Theory of Relativity is a famous example of a complicated geometry, where its properties vary -- far from any mass, the geometry of space is quite similar to Euclidean geometry, but the rules change near the presence of large masses like planets.\n\nThat one isn't so easy to visualize, but it *is* technically important, and that's true of most non-Euclidean geometries.\n\nIt's also important that it is possible to look at the geometry implied by pretty much any set of equations, and reason geometrically about those equations. Among zillions of examples, this is related to \"Elliptic Curve Cryptography\", which for some time has been one of the most important kinds of cryptography.\n\nSo non-Euclidean geometry pops up in all sorts of unexpected technical or scientific topics.\n\nYou can also use non-Euclidean geometries to describe science-fictional concepts like alternate realities of various sorts -- not that writers *need* to use formal math in their stories, obviously.",
"Here is an excellent attempt to make Lovecrafts thematic references to mathematics actually fit his cosmic horror storylines: _URL_1_\n\nHere is a fun game that viscerally demonstrates how easy it is to get lost in hyperbolic space: _URL_0_",
"Euclid wrote out a list of basic assumptions of geometry.\n\nOne of them is considered clunkier and harder to prove than the others, that any pair of corresponding points on two parallel lines will be the same distance apart as any other pair of corresponding points.\n\nNon-Euclidean geometry is a variety of modifications to this, such as the hyperbolic geometry pioneered by Lobachevsky. The study of how stuff works under the set of rules for this is Non-Euclidean geometry.",
"In Euclidean Geometry the three vertices of a triangle will always add up to 180 degrees.\n\nNon-Euclidean will not. \n\nThat is the long and short of it. ",
"Euclidean geometry explains how shapes work on a flat surface. Non-Euclidean geometry explains how shapes work on concave or convex surfaces. \nYou’ll notice many rules for the geometry we are taught get altered to fit this new type of surface. For example, all angles of a triangle won’t add up to 180. Depending on wether the surface is convex or concave decides wether the angles will add up to less than or greater than 180.",
"For any 5 year olds:\n\nEuclidean geometry is on a flat surface. If you draw a triangle on a piece of paper the angles all add up to 180 degrees.\n\nNon-Euclidean geometry is on a curved surface. If you draw a triangle on a basketball (sphere) the angles will add up to more than 180 degrees.\n\nThis is a gross oversimplification, but I think that it get the concept across."
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1kjqtq | why the inclination of the planet effects temperature more than distance from the sun? | In my mind the fact that the difference between nearest and furthest approach to the sun is ~5E7 km should have a much larger impact on the temperature across the Earth, which obviously isn't the case.
| explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1kjqtq/eli5_why_the_inclination_of_the_planet_effects/ | {
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"The best way I had someone explain this to me was with a flashlight and a sheet of paper. Imagine the flashlight shining directly onto the sheet of paper, it would make a circle of light that you could see. if you were to tilt that paper back a few degrees, the circle would get larger and stretched out. in other words, you have the same amount of energy, but over a larger area. The reverse could be demonstrated by using a magnifying glass to focus that energy onto a single point, resulting in an energy concentration high enough to to set something on fire. Its all about how much area that energy is spread over. "
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2wdlgd | negative numbers | Ugh. Eight year old in the back seat. ELI8. Plz help. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2wdlgd/eli5_negative_numbers/ | {
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"*The* negative of a number x is the one number which when you add to x you get zero (which is the identity of addition). *A* negative number is the negative of a positive number. A number is positive if it is greater than zero.",
"8 year olds are going to understand none of these answers.\n\nJohnny is one meter tall. If he stands on a one meter box he is one meter off the ground. If he stands in a one meter hole he is negative one meter off the ground.\n\nIf Johnny has zero dollars, borrows one off Jimmy then spends it, he has negative one dollar because he owes one to him.\n\nedit: Johnny's height is irrelevant actually."
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33es7g | in a nuclear blast, why does the force start outwards, then seemingly retract back? | _URL_0_
Take this for instance. The dust and explosion blow outwards, force wise, but then it starts coming backwards/back. Why does this happen? How does the force reverse? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/33es7g/eli5_in_a_nuclear_blast_why_does_the_force_start/ | {
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"The initial shockwave creates the outward burst but then the backdraft of the oxygen being consumed to feed the fireball and the heat from the combustion give it the beautiful mushroom effect. ",
"Cool video there. \n\nIt's incredibly hot in the center of a thermonuclear bomb. This heat causes gases to rise very quickly after the explosion (thus the mushroom cloud). Gases from the surrounding area rush in to fill the void left by these rising hot gases. Basically it's wind. ",
"It has to do with pressure. When the bomb explodes it make the air around it expand and this increases the pressure. The pressure wave travels outward leaving less air where it exploded and more where the explosion traveled to. When the pressure wave dies out the air rushes back in to fill the empty space made by the explosion.",
"Not exactly an expert, but this should be fine enough:\n\nIn initial phase, a chemical reaction causes atoms to produce very high amount of energy, which produce a lot of heat, and heat causes gases to expand. When chemical reaction ends, energy depletes, and without the source of heat, the temperature gets lower, which causes the opposite reaction - the gases detract to even out the atmospheric pressure.\n\nIn other words, there is very high pressure inside the explosion, which after disappearing, creates something similar to a vacuum, which then pulls the air back to even out the pressure.",
"Because Nature abhors a vacuum is why. Is allot more intense than that simplified explanation, not even sure I recall who stated that. The statement is true and that is why. In physics it is Horror vacui, which I always thought was the coolest Latin phrase I would seldom if ever use. "
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4h17xr | why is the toilet paper holder so low in many public restrooms? wouldn't it be just as easy to put it a little higher to be more ergonomic? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4h17xr/eli5_why_is_the_toilet_paper_holder_so_low_in/ | {
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"Just a guess, but I wonder if this was to prevent people from unrolling five feet of TP, three feet in and you're either touching the ground or, if pulling it towards you, at your body\n\n\nAgain, complete guess",
"Are you by anychance a tall mofo that has never had to take kid to the bathroom?"
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ads92i | why exactly do people raise their voice to appear more friendly/less threatening? | You know, like the ‘phone voice’ or ‘customer service voice.’ Similarly, why exactly do we shout when we are trying to appear more intimidating?
EDIT: it’s probably obvious but just to clarify, for the first question I mean the pitch of their voice not the volume. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ads92i/eli5_why_exactly_do_people_raise_their_voice_to/ | {
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"Babies and young children have higher pitched voices, so our brains are probably wired to think of those voices as less threatening or friendly\n\nEdit : changed lower to higher ",
"One thing that may play in here is that typically, smaller things make higher pitch noises. If you listen in a forest for a long time, and hear all the animals, you'll hear (some) insects make really high pitched noises, then come birds, then small animals. The largest make the lowest pitched noises. IIRC, researchers who work with ecosystems can hear what is missing in an ecosystem because every species occupies a different frequency. \n\nThat would lead to an association of high pitched noises/voices with less potential danger than low pitched noises/voices. Note: this is just conjunction and guesswork on my part, and should not be taken as fact."
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6rtb4x | why is it that our bodies can't stop producing heat rather then use sweat to cool of excess heat it creates? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6rtb4x/eli5_why_is_it_that_our_bodies_cant_stop/ | {
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"Mainly because we generate heat as a byproduct of the internal processes that keep us alive.\n\nIf you stop these processes, you stop generating heat. But you also die.",
"To answer this you have to understand that heat,as energy is a product of the chemical reactions going on in your body. In order to keep your cells alive there a millions of reactions taking place inside them, the energy starts out as your food basically. This all produces a net amount of heat that must leave your body to prevent it from getting damaged.\n Sweat is there to control your body temperature which must be kept constant, if your core temperature drops or rises above normal your cells are unable to survive and start dying due to the stress; their proteins only work at specific temperatures and conditions to keep them alive.\n\nELI5: Your body is like a machine that gets hot when you use it for a long time. It needs to be able to cool down or it might melt and stop working.\n\n-Biomed scientist here if you have more questions",
"When your body creates energy for your muscles, brain and the like, it also creates heat as a byproduct.\n\nThat heat is important to maintain functions that happen within the body, if the temperature is too cold or too hot things would stop working.\n\nYou need the body to be constantly in the same temperature, and starting and stopping the process would mean that the body is vulnerable to sudden temperature changes.\n\nThink of it like water in the shower, when it's too hot you don't turn on and off the hot water but turn on some cold water."
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eh5ibq | how can the original super mario bros file size only be 32 kilobytes/kb? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/eh5ibq/eli5how_can_the_original_super_mario_bros_file/ | {
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"The code is very very very very very efficient. Programmers in the 70s and 80s were taught more intensely about how to make your code more efficient because, at the time, resources were *expensive*. Nowadays we have 8GB or even 16GB of RAM that is considered standard. We don't really NEED to worry about efficiency as much as we used to. \n\nEverything else is just using efficiency with graphics (i.e. that one shape for every cloud or clump of grass or whatever) and just keep reusing that same thing.",
"Programming back then was different - you had very few resources, so you needed to be efficient - there was no way around it! Also, there weren't so many layers to interact with - your code worked close to metal instead of calling OS functions (like today with the Win32 or DirectX API).\n\nNowadays... well, the whole agile thing put more emphasis on delivering new stuff every 2 weeks instead of efficient programming.\n\nBut if you want to be amazed with more recent creations, check out a [modern FPS in 96KB](_URL_1_). And also check out [Pouet demos](_URL_0_).",
"Don’t forget the simple things, like clouds and trees using the same sprites, any plenty of stuff just being recolored.",
"Graphics. Its almost entirely the very simple graphics.\n\nPeople are telling you a lot about how no one programs \"efficiently\" anymore and while that's debatable its also irrelevant because its mainly the graphics that make the difference is size. The sheer scale of the difference should make this clear. The textures alone (compressed for efficiency) for the original release of Skyrim were nearly 1.5 gigabytes, forty-seven thousand times larger than all of Super Mario Bros before we even get to game audio or object models which are a similar amount of data. Likewise a single 4K texture for a modern game is 2600 times larger than the entirely of Super Mario Bros.\n\nNo amount of optimization can get around this difference.\n\nSuper Mario Bros used a very limited palate of colors and a very limited collection of 2D sprites in order to create its world."
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4u9mob | what's actually happening when you get a charlie horse in your calf? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4u9mob/eli5_whats_actually_happening_when_you_get_a/ | {
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"For those confused: Charley Horse is another way of saying muscle spasm that is intensely painful and can last for several minutes at a time. So, what causes these horrid spasms?\n\n* inadequate blood flow to the muscle\n\n* muscle injuries\n\n* exercising in excessive heat or cold\n\n* overuse of a specific muscle during exercise\n* stress, most often in the neck muscles\n\n* not stretching before exercise\n \n* nerve compression in the spine\n\n* taking diuretics, which can lead to low potassium levels\n\n* mineral depletion, too little calcium, potassium, and sodium in the blood\n\n* dehydration\n\nSo aside from the common ones such as not stretching and not having enough nutrients/vitamins etc, what is the reasoning behind these causes? Well for exercising in the heat or cold it actually causes your cells to either die (by exploding, gruesome right?). For stress and overuse it causes them to not respire aerobically (with oxygen) so they start respiring anaerobically (sans oxygen due to the huge demand which is what also causes your heart to race and your lungs to take deeper breaths) leading to a buildup of lactic acid (what causes soreness after exercising). Too much acid and the muscle tenses up as a reaction by the cells to prevent themselves from being damaged. \n\nSo why does nerve compression cause cramps? It's because of altered neuromuscular control which is science-talk for \"The muscle doesn't know what to do so it keeps doing what it was just told to do\". If the last command was \"contract\" then the muscle will keep going until it starts to anaerobically respire and then succumbs to lactic acid. \n\nI hope this helps :)",
"I see a lot of causes, but to understand what is actually happening, you need to understand the anatomy of a muscle. Muscle fibers are strands with a male and female end. The female end has a bunch of cilia that pull the male end into the female end bit by bit when you tell your muscles to contract. Imagine your friend holding their arm out straight and you take your arms, one on top of the other, and,with your fingers, your two arms move their way up your friend's arm. This is roughly the way one, singular muscle fiber behaves. Your muscles are comprised of bundles of bundles of muscle fibers. Think cabling on an extension bridge. Each cable is made of individual strands, and these strands are bundled together into cables which are then bundled together to make the larger cables that hold up the bridge. So, all that in mind, when you experience a Charlie horse, which can be caused by any of the reasons mentioned, one grouping of your muscle fibers is being told to contract. The rest of your muscle fibers are not being told to contract, and there is essentially confusion. WHY THE FUCK ARE YOU GUYS CONTRACTING? I DONT KNOW, WHY ARENT YOU GUYS CONTRACTING??? This is what causes the discomfort. When you get one, stretch in the opposite direction of the contraction. If your calf is cramping, pull your toes toward your face. This will hopefully tell the muscle fibers that were so confused to reset to what the rest of their fibrous brethren were doing.",
"* Low potassium or sodium\n* Low magnesium or calcium\n* Deep vein thrombosis (one or several blood clots)\n* Muscle fatigue leading to stiffness\n* Spinal stenosis and/or root nerve irritation/compression\n* Not enough water\n* Diabetes",
"Ohhh I have an answer! (At least regarding cramps following a day of exercising!) \n\nAlright so every muscle in your body has a few protective reflex system built in. These reflexes provide continuous feedback to the spinal cord through sensory information, informing the brain about the functioning status of each muscle instant to instant.\n\nThere is the Muscle Spindle reflex (In the belly of the muscle) which is responsible for stretch so if you’re brain gets a signal saying there's too much stretch the reflex will cause the muscle to contract. (Think of this as an emergency brake!) Now this sensory organ can be excited in two ways: \n1. by lengthening the entire muscle,\n2. contraction of the spindle ends, even when the muscle itself remains the same length. \nSo anytime your brain thinks there are risks of over-extension, the muscle spindles kick into gear. (this is interesting because even if there's no stretching, like in your sleep, the ends can still be activated triggering a response! We are still not a hundred percent clear on how this works!) \n\nSo let’s talk about the second protective reflex- Golgi Tendon Organs. These are located in the tendon of the muscle (the part that attaches it to bone) and they sense too much tension. So if you are over contracting a negative feedback system equalizes these contractile forces among the stressed fibers. (This way you don’t contract muscles hard enough to, say, snap your own bones.)\n\nNow as you are active and these protective mechanisms are constantly adjusting, the golgi tendon fatigues while the muscle spindle will actually be allowed to strengthen in it’s absence. And just like that you get excess contraction (overcompensation) leading to painful cramping! \n\nIf you grab either end of the muscle and squeeze toward the belly of the muscle, you can actually help reset the spindle. \n\n*Disclaimer: source- medical school. I am not a doctor, also there are other reasons for cramps including excess metabolites, nutrient imbalances, dehydration and certain medical conditions. \n\nAlso this is by no means a complete explanation (I don’t even mention fiber types!) So if anyone who has a better understanding, wants to correct my explanation or elaborate, please feel free! \n\n\n\n\n\n\n\n\n\n\n\n\n "
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ev8jcv | why are we not pushing for more "planting" of algae instead of trees? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ev8jcv/eli5_why_are_we_not_pushing_for_more_planting_of/ | {
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"While algae are responsible for a majority of the CO2 scrubbing worldwide, they're not the most efficient in terms of volume of CO2 per square foot. The reason they're so responsible is because the oceans are HUGE. But in a square mile of land, trees would be far more effective than if we converted that square mile into a pond with algae in it. Not to mention that Trees provide other usefulness as a byproduct of their CO2 conversion, in the form of the wood they produce which we also require for building materials and/or fuel.",
"tree lives for tens of years, and retains CO2 in it while it is alive. \n\nalgae dies in a few days (or a year at most), and will release CO2 back as it rots.\n\nso tree is plant-and-forget, while algae farm will need to be constantly maintained.",
"Because we aren't going around and destroying all the algae population in the ocean as we are doing with trees. \nDeforestation has a way bigger impact on the climate than just trapping CO2 in their trunks, they also serve as habitats for millions pf animal, fungal and plant life, which can be very beneficial for biodiversity.",
"Algae grow naturally by themselves and will virtually automatically colonize all available living conditions very quickly. Algae are restricted more by available sunlight, minerals and animals eating them, most of which there is very little that humans could do anything about. It is theoretically possible to create artificial algal blooms by adding minerals to the oceans, but that would have consequences for the ocean fish levels and would present the issue of who pays for it and can the minerals themselves be obtained without damaging the ecosystem. _URL_0_"
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47pmvs | why do commercial airline engines have the twirly spiral thing on the turbine? | [Here](_URL_0_) is an example of what I am talking about. Is it purely cosmetic? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/47pmvs/eli5_why_do_commercial_airline_engines_have_the/ | {
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"You can tell if it's spinning that way. Apparently it also stops birds from thinking the jet engine is just a big tube. \n\nSimple enough really.\n\n_URL_0_",
"It's there so you have an idea how fast the turbine is spinning. The turbine blades will become blurry fairly quickly, but you'll be able to see the spiral even if it's spinning quickly. ",
"It allows ground crews (who are wearing hearing protection) to see if the engine is running. "
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6cow6a | once a phone runs out of charge, how does it continue to display the "out of charge" screen? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6cow6a/eli5_once_a_phone_runs_out_of_charge_how_does_it/ | {
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"A battery is not completely depleted at that point, but would be damaged if the battery is drained much further. Completely draining a lithium iin battery to zero potential would damage the battery, possibly leading to a violent failure.\n\nThe out of charge screen, or led, serves to reassure the owner that the phone is functional, but has a drained battery. ",
"Because the battery isn't completely out of charge. It's programmed in such a way to prevent use below a certain battery level. Most phones turn off at 2% but sometimes you'll even see the phone say 0% when you turn on the screen. However that's not entirely accurate. Very close to being empty yes, but not entirely. If it was it would be impossible for the phone to turn on."
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2ngdaj | what makes coffee 'good?' | Why is some coffee better tasting and 'smoother' then other brands? Is it roasted differently? Grown differently? I can tell the difference between differing coffees but I don't know why. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2ngdaj/eli5_what_makes_coffee_good/ | {
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"One of the huge things is freshness. If you go to someplace that roasts their own beans you will probably notice their coffee tastes much better then something you buy at a grocery store that was roasted more than a month before you bought it.",
"Texture is a seldom mentioned, yet very important factor in how good coffee is. There is nothing worse than piss-water coffee that somehow manages to be thinner than water. I want some substance to my drink."
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4xcb56 | how anesthesia works and why local anesthesia injections aren't sold as painkillers at drug stores | What does anesthesia do to my nerves that numbs them? Since it's so effective, why can't it be sold for personal use in cases of extreme pain? (Not talking about general anesthesia, I understand there has to be a very calculated specific dose and can be deadly if not done properly) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4xcb56/eli5_how_anesthesia_works_and_why_local/ | {
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"Local anesthesia is sold over the counter. Lidocaine and benzocain. But its not that totally safe either. Lidocaine can cause breathing problems.\n\nBengay is toxic if overdosed.",
"Lidocaine acts by blocking channels in your neurons that release sodium ions. Sodium ions moving across channels in the membrane of the neuron is what causes an action potential, or an electrical signal that moves between neurons carrying sensory information like experiencing pain.\n\nBecause lidocaine actually stops any signals from coming in from that area it is more appropriate to use other forms of analgesia that just stop pain specifically. (For example, by affecting the part of your brain that consciously perceives pain.) Your brain needs to be able to communicate with the rest of the body so stopping all signals from coming in can cause a multitude of other systems to be potentially negatively effected in that area. \n\nLidocaine can also be used to treat arrhythmias by IV injection but can cause cardiac arrest if injected inappropriately. Or say you accidentally inject it in/close to the nerve that goes to your lungs (or it travels there via your spinal fluid, etc...) you can cause respiratory arrest. It's not a good drug to let people do with it as they please as it can be fatal if used incorrectly.\n\n"
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4ig1gl | why do carrots bend outwards when cut along their length? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4ig1gl/eli5_why_do_carrots_bend_outwards_when_cut_along/ | {
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"I have been reading jokes all morning and I thought this was another joke. I was expecting something along the lines of \"Because bowing is too difficult.\" or \"to prevent them from screaming.\" But to answer to ELI5, I believe it is because of the tension on the outside is greater than the tension on the core.",
"There are three things going on here:\n\n1. Over time, a vegetable will dry out from being in contact with dry air, even in your Fridge's crisper drawer.\n\n2. When a vegetable dries, it shrinks.\n\n3. The outside will dry faster than the inside since it is in contact with the air.\n\nAll of those together, we see that the outside is shrinking faster than the inside. This creates mechanical stress inside the carrot, which stores energy like a spring. You don't see the carrot warp because the outside of the carrot is pulling it in every direction equally, but when you cut it, the carrot is not symmetrical anymore and it bows.\n\nYou can see another application of this effect in [bimetallic strips](_URL_0_) with some handy pictures.\n\nSo why does this happen in carrots and not other vegetables or fruits? This gets more complicated, but one reason is that the water in other fruits and vegetables flows more than in a carrot and it dries homogenously. Water flows is a carrot, but mostly along the axis, and not radially, since it is divided in growth rings, or separate 'vascular bundles'. This allows the outside to dry and the inside to stay... moister."
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95ly4s | despite the fact that railroad crossings are built to compensate for added weight of trains, how do they have such a short life expectancy compared to road and other rail structures? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/95ly4s/eli5_despite_the_fact_that_railroad_crossings_are/ | {
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"They're basically built-in potholes. The passing vehicles jump the rail gap and slam their tires against the pavement on the other side millions of times a year.\n\nUsually the rail itself is still fine when the crossing gets repaved, but the pavement is obliterated from cars grinding away at it five thousand times a day.",
"Potholes form when a small crack in the pavement is filled with water and then freezes. The frozen water expands, causing the crack to widen, allowing more water in, making a bigger crack next freeze. \n\nConcrete always cracks. Always. We put in crack control lines to make it crack where we want, but eventually someone's going to hit it just right and a baby pothole will be born. Cars rolling over the tracks will come down hard on the pavement, giving an impact load more likely to crack the concrete than the gentle rolling load of typical sections. \n\nFurther compounding this, steel deflects and vibrates as a train goes by. That creates more cracks and makes it easier for potholes to be born. \n\nThere are ways to prevent this. The railroad adjacent slabs could be poured with more reinforcement, and a harder brand of concrete. But what's more likely is they just accept that the slab will need continuous work and everyone makes a bit of money regularly. "
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akg1dj | why is the audio mix on movies/tv so much quieter than youtube/online video? | Just something I've noticed where I have to raise the volume on my TV significantly to hear dialogue on an HBO show compared to watching a YouTube video.
Is there a technical reason for this, like higher volume required meaning the range of sound can be better for more premium content, or is it just the way things work? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/akg1dj/eli5_why_is_the_audio_mix_on_moviestv_so_much/ | {
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"Because people who don't know how to record digital files think that red is a great thing and obviously means that it's barely loud enough, as opposed to actual recording engineers who know what they're doing... Sometimes. ( dynamic range)",
"There are different loudness targets (if you will) for different mediums. This is so (for instance) you don't get your eardrums blown out when the next song comes on your Spotify playlist.\n\nThe targets are measured in units called LUFS (Loudness Units Relative to Full Scale.). So when you mix for TV in the US, the audio should reach only -24 LUFS (that's negative 24). Streaming (Spotify, YouTube, etc.) is -14 LUFS, significantly louder than HBO.\n\nAlso, as u/audiollectial stated, a lot of YouTubers don't know what they're doing and crank it (and distort it). Additionally, there's the dynamic range to consider. (The dialogue will be more quiet so that explosions and stuff like that sound louder in comparison).\n\n[_URL_0_](_URL_0_) ",
"It's hard to answer your question completely without knowing what kind of YouTube videos you are watching. HBO is professionally produced and they tend to go for a cinematic experience with a lot of difference between the quiet parts and the loud parts.\n\nYouTube content can be created by anyone so some folks will create cinematic content like HBO does and lots of others will create normal content where the audio stays at a nominal level. Also many folks don't understand or use professional techniques so the audio can be all over the place in terms of level, quality, etc. "
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6b98sr | why is gravity an acceleration? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6b98sr/eli5why_is_gravity_an_acceleration/ | {
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"Because it makes your speed increase( or decrease ) over time. That means that the amount of extra speed you gain from it depends on the time you spend getting affected by it.\n\nI did not fully understood your question. Can you be more clear so I can help?"
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69chcv | how do led thermometers work? | How can you get temperature information from lighting something with an LED? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/69chcv/eli5_how_do_led_thermometers_work/ | {
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"Op are you talking about Laser Temperature Guns/thermometers?? (That tell the temp after pointing the device and laser at an object) \n\nIf you are: the laser doesn't have anything to do with the temp, it just aligns the sensor that is located right next to the laser on the front of the device. ",
"\n\nAn infrared thermometer is a thermometer which infers temperature from a portion of the thermal radiation sometimes called blackbody radiation emitted by the object being measured. They are sometimes called laser thermometers as a laser is used to help aim the thermometer, or non-contact thermometers or temperature guns, to describe the device's ability to measure temperature from a distance. By knowing the amount of infrared energy emitted by the object and its emissivity, the object's temperature can often be determined. Infrared thermometers are a subset of devices known as \"thermal radiation thermometers\".\n\n"
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3kqnjf | as a non-american, can someone explain to me how come ron paul's presidential campaigns had such a huge popular participation taking over social media while rand paul's current campaign - his libertarian son - doesn't show a fraction of that enthusiasm and popularity? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3kqnjf/eli5_as_a_nonamerican_can_someone_explain_to_me/ | {
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"Ron Paul and Rand Paul are not the same people. Rand is seen as much closer to the Republican mainstream, much more ideologically compromising (at least with conservatives) than his father. Ron Paul got a lot of support from moderates and even conservative Democrats, but Rand just appears to be going after hardline conservatives.\n\nNot to mention that a lot of the people who supported Ron back in 2012 are now leaning towards other \"fringe\" candidates like Trump and Bernie. Ol' Randy doesn't have a tenth of their charisma, or his father's come to think about it."
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2kn618 | heat therapy vs cold therapy on sore muscles? which is better for what? | I have inflammation occasionally in my chest, and I have heard both to ice it and to use heat, but I don't understand how or why it works and what method is best for which issue. Please help explain. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2kn618/eli5_heat_therapy_vs_cold_therapy_on_sore_muscles/ | {
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"Heat-cold therapy is generally used when soreness is present due to *impact* trauma. The most common causes of this are strains and aches related to physical activity, and bruising from direct impact. \n\nCold is applied first to reduce the amount of swelling, relieving some of the pain associated with it. This can be done within the first 48 hours of the pain starting. \n\nHeat is applied after the initial pain has subsided and the swelling has gone down. The heat increases circulation in the area, relaxing the muscle and promoting the healing process.\n\nHOWEVER, if you're getting inflammation in your chest that is not associated with any physical trauma, this may not be the best course of action. If the inflammation is specific to a particular MUSCLE, then by all means give it a go. If not, then it's more likely an internal problem that needs to be addressed.\n\nIf you're feeling any of the follow, or have experienced any of the following, **go see a doctor. Now.** \n\n* A sudden feeling of pressure, squeezing, tightness, or crushing under your breastbone.\n* Chest pain that spreads to your jaw, left arm, or back.\n* Sudden sharp chest pain with shortness of breath, especially after a long period of inactivity.\n* Nausea, dizziness, rapid heart rate or rapid breathing, confusion, ashen color, or excessive sweating.\n* Very low blood pressure or very low heart rate.\n\nIn any case, chest pain that comes and goes without an obvious cause should probably be checked out. Again, if it's just a strain muscle issue, go ahead and ice it. When the soreness starts to ebb, you can start applying heat. Light stretching can help as well, but let pain be your guide on that one. "
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14rr08 | in monster movies, humans always see the monsters move slowly. is that accurate? do ants 'see' humans as slow-moving? where is the line that crosses the boundary? | As a young child, I never saw adults as lumbering giants. I'm pretty sure the shortest person in the world wouldn't see the tallest person lumber about.
So at what size would we perceive something to move 'slowly'? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/14rr08/in_monster_movies_humans_always_see_the_monsters/ | {
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"This is a really good question, I hope we get a decent answer. \n\nEdit: I sometimes like to think of it like water drops. To ants, water drops are these big circular 'thick' things. To us it's mostly slick and runny. Additionally at the very small level really small bugs (really small) perceive the air as quite thick and hard to negotiate. While we see it as quite easy to walk through, I'd imagine air would be different to large bodies. \n\nTL:DR Constants in the world stay the same and are perceived differently by larger/smaller bodies. ",
"You can probably Google how they do model based special effects and find some good results (I'm at work, so my access is limited). I know in older sci-fi stuff like Thunderbirds and Captain Scarlet they'd slow down model buildings blowing up/falling over etc to help convey scale.\n\nIt's also why in Team America when the Eiffel Tower falls over, it intentionally looks so ridiculous, because they don't slow it down in post production.",
"I am in no way qualified to answer this but here's my two cents anyway...\n\nIt seems to me to have to do with the amount of distance that is covered when performing an action. If I am an average sized person (say 6 feet tall), my stride length is about three feet. So my foot moves three feet with each step. Let's say that it takes a half of a second to take a step. That means that my foot travels at a speed of 6 feet per second or roughly 4 miles an hour. (Note that I am not trying to calculate my walking speed, that is I'm not trying to figure out how fast my whole body is moving over a distance. Rather I am trying to figure out how fast my foot is moving as it goes from the back of my stride to the front. Hope that makes sense.)\n\nNow, let's say I was a monster! I am no longer six feet tall. Now I am 600 feet tall! If my height was scaled up in this way, my stride length would be too. So now my foot travels 300 feet with each step that I take. If my strides took the same length of time as they did when I was 6 feet tall (a half of a second), that means that my foot travels at 600 feet per second which is roughly 400 miles per hour! You can imagine how silly it would look if a big hulking Godzilla creature scampered into Tokyo with it's feet whirring at 400 miles per hour. \n\nIt's not that we are so little that bigger things appear to move slower. It's that bigger things just have more distance to move. The speed may be the same or even a bit faster, but the distance is greater so it takes more time for a giant to make a similar movement as an average sized human.\n\nSo that's my explanation. Reddit, you are now free to point out it's many flaws."
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4mbcjh | if computers are doing most of the trading, and markets are open to anyone investing around the world, why do stock markets only operate for like 8 hours a day? and what are all those people doing on the nyse floor all day? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4mbcjh/eli5_if_computers_are_doing_most_of_the_trading/ | {
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"There are no \"people on the floor\". At least not in the 80's sense. They stay in their offices and do accounting and legal compliance.",
"Much of our financial/banking systems are still based around business hours and daily open/closes. It's hard to explain, but we still need daily \"markers\" as trigger points to do things.\n\nThat being said, there is such a thing as after-hours trading, which happens overnight. Not sure the details on this, but I know you can't trade *everything* after-hours, just certain things.\n\nAs for what goes on at the NYSE trading floor, these days, it's mostly just news reporters & commentators. No one needs to be there for trading - it's mostly just a big TV set.",
"I'd also like to add that the financial system is very old and does not like to change. \n\n- We didn't value stocks down to the penny until 2001 (before we used fractions like 1/8 based on an old 400 year old Spanish tradition)\n- The \"Ticker\" for a stock is based on old machines that would make a ticking noise when writing off stock symbols and their prices to various machines around the world before computers were a thing.\n- Bonds have a \"Coupon\" because when you wanted your interest payment from a bond you would cut out a coupon and take it to the bank and they would exchange your coupon for money (we don't use coupons anymore, but it's still called a coupon)\n\nI'm sure there are other examples, but basically, our financial system is VERY used to tradition, and the times the markets are open is a big deal to how the infrastructure in the system works, and financiers do not like change.",
"The nyse floor is a theatre for journalists. High frequency trading is done by computers. Over-the-counter trading is done in the banks' own offices",
"Trading is open near 24 hours around the world, it's kind of like how you can go to an ATM to get money whenever you want, but if you want to go talk to a bank teller they are only there during work hours.\n\nI am a trader and I can tell you that most markets are open near 24 hours for electronic trading. The specific market I trade (us bond futures) is open from 6pm eastern to 4 pm (22 hours a day sunday night through friday afternoon) with the 2 hour shutdown being where stagnant orders from the day are cleared out and servers are restarted. \"After hours\" and \"before hours\" trades are frequently highlighted on cnbc when stocks report earnings, you just generally have to pay to have access to these trading times.",
"In addition to what others have said, you also have to keep in mind is that a lot of computer trading is about taking advantage of non computer trading market forces. If it seems like a stock is priced at X and people are looking to buy it up to 1.1X then it will buy the stock at 1.05X and then sell it on. It isn't that computers are super smart traders who know which companies are over valued and undervalued. Computers just look at who is trading what and at what value and which stocks are out there that people are going to be willing to pay a bit more for and then use their ability to quickly buy and sell those stocks to make money. While you could in theory run them after hours, it wouldn't make sense because the biggest benefit of them is that they can make deals much quicker based on market forces then people and use that fact to make money. If people aren't trading then its very difficult to make money through that analysis. \n\nAutomatic trading generally makes its money on high volumes and reacting to the market forces. After hours when few people are trading, its hard to determine those market forces and being able to make a high volume of transactions is rather pointless as most other people trading are just following the same strategy you are.",
"From my experience I'd say a few things. Automatic trading are used mainly for high frequency trading, wich is a very specific niche that acts on very short spans of time.\nBut it's very hard and I think nearly impossible to automatise regular trading because it involves a lot of other factors like analysing the prospects of a company, in what do they plan to invest, what you think of its market etc. There is a lot of intuition and feeling involved, of betting.\nI have worked with traders and you have to understand that there is different types of traders and different types of products. Some of them will manage the portfolios of clients, some others will use algorithm based tools but they will closely monitor what the algorithm is doing. In order to use an algorithm, you also need to initiate it, to enter fine parameters in order for it to work efficiently. During the life of an algorithm, you might need to cancel it, to tune it or to replace it. You have traders working on \"slow\" products, for example rates. Anyway, trading involves humans at every step.\n\nOne other practical reason is that trading systems need maintenance. It's a pretty complex task to have servers running 24/24h, and it involves a company to have employees available at the same time, at least at a support level, which is costly. So when the market closes up, it allows IT teams to deploy new versions, to backup things or whatever. But it is often the case that a broker needs its servers to run 24h/24 when it has multiple clients trading other multiple places. Once Paris closes up, Taiwan will open, and then New-York etc. Allowing the client to trade all other the world involves a high-availablity architecture.\n\nI would have been much more precise if english was my native language !",
"HFT (high frequency trader) here. You are right that most trading is done electronically. That said, there are still many tradable products that do trade mostly on the floor. Take, for example, something like Eurodollar options. Similarly, there are plenty of products that do trade all day (23hrs typically, so that computer systems can restart or reset or be upgraded for the next day). \n\nA large factor that determines whether something trades electronically or largely on the floor is what kind of participants provide the retail (customer) interest. Products that receive much of their flow from mainstream consumer brokers (Etrade) and prevalent investment banks or funds (Goldman) tend to be very electronic - these brokers are advanced and efficient, and execute their trades electronically. Less developed firms or large retail interests (foreign) may still go to the exchange floor to find the best, most competitive, and most liquid market for their likely large trade sizes. For the most part, the people you see on the floor of NYSE are symbolic, are trading officials (rarely used except for drastic stock moves in a particular company, IPO), or are there to satisfy exchange rules that provide electronic traders fee incentives (must have a guy on the floor in order to get $0.01 cheaper fee per trade, as a crude example). \n\nLastly, why don't all products trade 23 hours? A big part of it relates to what the costs are to support trading systems being operational at night (who will deal with bugs) and whether the trade volume warrants this cost. Exchanges with many liquid and active products, especially those with international interest) will take on the challenge (CME). Others, like NYSE, can't justify the cost at this time. ",
"I used to consult for an investment bank.\n\nTokyo is open 0000-0600 UTC. London is open 0800-1630. New York is open 1430-2100 UTC.\n\nI know for some technical operations, Tokyo is running things from 2200-0600 UTC, London is from 0600-1400 UTC, and New York is from 1400 to 2200 UTC. Control shifts from one city to the other in continual eight hour shifts from Monday's Tokyo opening to Friday's New York closing.\n\nIf a computer or network connection is having problems, technicians have some downtime between Tokyo closing and London opening, and New York closing and Tokyo opening to fix it. For more complex projects, they have between Friday's New York close and Monday's Tokyo opening to get them done.\n\nInsofar as people on the floor of the NYSE, or the CME or what have you - they're not there much nowadays. Go back 10-20 years and a lot of people were on the NYSE or CME. It's been computerized, so most of those people are gone. Both places are a ghost town comapred to what they were 10-20 years ago.",
"source: am finance in new york\n\n* The NYSE is not open for floor trading 8 hours a day. [It is open from 9:30 AM to 4 PM EST](_URL_0_). So actually just 6 and a half hours.\n* There is electronic trading which takes place outside of these hours for many stocks on [NYSE ARCA](_URL_2_). They start at 3:30 AM.\n* If you so desire, you can do over-the-counter trades (that is, you get on the phone and call someone directly) at any time.\n\nOn the question \"Why are these hours so short?\" There are a couple answers.\n\n* To get a good price on a stock and have a functional market, it requires buyers/sellers to be present. Lots of them. It is helpful that people be awake and at work to achieve that.\n* When there are few people around (because they are sleeping, say) the prices will be bad - you want the best price, they want the best price, and if there are few people around, those prices will be very different.\n* That is called \"liquidity\". The hours for floor trading at the NYSE are close to when lots of people are actually around.\n* In working in finance, to get \"the right price\" for a stock we would use only prices during the floor trading hours except in extreme conditions, because of this \"people not being around and prices being stupid\" problem.\n\nAs for why there are floor traders doing this in person:\n\n* Most trading is electronic today, even on the NYSE. [About 15% of trading is conducted on the floor by humans in person.](_URL_1_)\n* Part of the reason it persists is just historical: we've been doing it for a long time and finance is resistant to change.\n* Part of it is because there is some value in having humans, in person, talking (shouting, really) at each other and communicating information to one another.\n\nI actually don't think floor trading is going to survive long, though. Other exchanges have ended this practice and it is increasingly done electronically. The NYSE is one of the holdouts for even allowing floor trading.",
"I would say one of the largest reasons for daily business hours on an exchange is the flow of company information or company reports. Most sensitive, concerning press releases are released before the market opens or after it closes, which allows people the opportunity to access and/or read it to get a level playing field for the next day's opening price. Sure, there is after-hours trading, but exchanges like NYSE prefer to have superior standards to OTC trading. ",
"Ton of misconceptions in this post. Before I switched careers, I was a high touch trader in New York and my cousin/few friends still work on the floor.\n\nFirst of all, don't listen to the people saying no one trades anymore or that London is the last trading exchange. There are floor brokers, called $2 brokers (since that was the going commission rate forever, nickname stuck) and they definitely trade. There are *significantly* less than there used to be, and that number seems to shrink every year, but I'll try to give the answer in a succinct way.\n\nBasically, the stocks have to be actually traded somewhere, managed by some book or person. That person is called the [Market Specialist, or Market Maker](_URL_0_). Without getting too technical, they exist and hold portions of stock to make sure the market stays *stable,* something that is still extremely hard to automate because a lot of what is *stable* and what isn't *stable* is relatively subjective. Many banks have posts on the floor where designated market makers will trade certain stocks and manage the books. Since most trading is automatic these days, and traders are tasked with buying or selling X around Y price over the course of a day, week, month, or whatever, they like to get in at the open, just to get a portion done, and finish those orders by the close. Market on Open and Market on Close are incredibly common trading tactics for numerous reasons, but why exactly isn't super pertinent to this discussion. Traders on the floor give face to face access to these market makers, void of any latency and can get a better feel from the foremost expert on how that stock trades. Information is key, and having that access is incredibly beneficial.\n\nTL;DR: Traders are on the floor to maintain open communication with the people who manage the market. It is hard to automate the market making system because it relies on keeping the market stable, which is subjective enough where you want someone watching."
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3ius1j | when countries perform "military exercises" together, what are they actually doing? | Are they testing each other out? Helping each other out? Do they use dummy rounds? Do the troops mix or do they fight against each other? Who leads the troops of either side of the exercise? Are there winners or losers? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3ius1j/eli5_when_countries_perform_military_exercises/ | {
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"It's so two or more countries can practice carrying out joint operations against a common foe. On the \"boots on the ground\" side the biggest thing they are learning is communication and movement. How to talk to each other about what they are seeing/doing/planning and how to go from point A to point B without tripping over each others toes, in other words. \n\n There is also a higher strategic purpose being served here. When countries stage this sort of exercise it's usually a very pointed message to another nation that if they cross a line the countries doing the exercise are prepared to work together against them.",
"Co-operation, make sure they are able to communicate effectively, synchronize procedures, and solidify their status as allies if/when the balloon goes up.",
"These are done usually with allies. The US and South Korea run annual drills like you just said. The US doesn't practice alone to save their secret new tech, because in a real world scenerio, we would be fighting right with South Korea.\n\nSo we practice coordinating searches. Looking for \"enemy subs\", trying to intercept as a team.\n\nPractice flying aerial blockades, etc.\n\nIt isn't like a game of paint ball where we all shoot each other, in fact, I don't recall if they actually fire rounds at eachother."
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325ww0 | why would you jail someone for not making child support payments, if they definitely can't make payments from jail? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/325ww0/eli5_why_would_you_jail_someone_for_not_making/ | {
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"To punish them. If they're already not making payments, putting them in a situation where they're not going to pay isn't going to mean you lose anything. Any jail is hardly the first response; you really need to mess up, bad, to go to jail for this.",
"Because our purely punishment based system has no interest in actually helping any member of the populace. \n\nOh I see you just started a new job after being unemployed through no fault of your own, too bad we are going to arrest you at work for not paying your child support last month while you were homeless. Now you're unemployed again, and homeless again, and still can't pay. That'll teach you.\n\nAbsolutely no shits given that everyone everywhere is worse off as a result.",
"Child support it stupid. I bet the mom uses it on her own shit most of the time. "
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2ck8ni | how, psychologically and sociologically, do cold-blooded organizations like isis emerge? | Now, the reason for me asking this is not because I am curious about the origins of the group, etc. etc., but rather how something such as mass executions, etc. be accepted and done by people that were very likely 'normal' back in time, and now expose many traits for which the term psychopathic falls short?
What is both the sociology and the psychology behind this? How can noone in ISIS, or Nazi Germany, or any other mass murdering movement drops their guns and says "woah, too much"? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2ck8ni/eli5_how_psychologically_and_sociologically_do/ | {
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"Fear. You are scared they will hurt you. They are searching you for dissent. You will be found and then you become the target. Thus, you commit atrocities. Lots of German soldiers had severe ptsd for stuff they had to do. Relatives included. They do not like what they did, but it was their family or yours. Always remember, that service was not optional for most young men. Similar for Isis. You don't want to join? Are you sounds American lover? Say goodbye to everyone you love",
"Group psychology is a very powerful factor. If everyone else is doing it then you are far more likely to follow suit. People do what authority tells them to do, see Milgram's experiment for a good example of this. Propaganda, racial tension and misinformation is also a major factor. In the case of the Nazis the German government had indoctrinated their people into believing that Germans were superior and that the Jews weren't really even full people. Furthermore they extensively represented Jews as sneaky and out to get them. Finally there were consequences. Those who refused to do their duty would be jailed and were at other physical risks from the government. They knew the atrocities would happen with or without them. \n\nThere were effects though. To continue with the Nazis, gas chambers were instituted to be better for the soldiers. They had been executing prisoners with guns but the soldiers tended to be at high risk of suicide. Some of Hitlers officers also went as far as to try to kill him. Not everyone put up with it. ",
"There's a free book by a sociology professor at the University of Manitoba called [The Authoritarians](_URL_0_) which summarizes his research on authoritarian personalities, both leaders and those who follow them. His book focuses a lot on the batshit elements in American politics, but it's also applicable to Nazi Germany, Soviet Russia, Islamic Fundamentalism, etc., etc. The world made a lot more sense after I read it.",
"A contextualisation of the ISIS movement is important. In Iraq during the years of Saddam Hussein the Sunni Muslims were minority leaders of a Shi'a majority state. Following the 2003 invasion and Hussein's fall a Shi'a majority government has been in power and has persecuted the Sunnis as a form of revenge for the years under Hussein. \nSyria is dominated by a sect of Shi'i Muslims in the Assad family. It is a Sunni majority state of approximately 74%.\nThe collapse of Syria has allowed for these extremist groups to gain a foothold in the region, Iraq was already unstable which allowed for this group to spread into Iraq.\nThese groups have emerged from persecution and being dominated by a group that isn't partial to supporting their views.\nThese conditions have allowed for extremist leaders to grow their powerbase and recruit disenfranchised individuals from this region.\nThe Sunni - Shi'a conflict/disagreement has existed since the death of the prophet in the 7th century\nSource, this is what I am studying at university."
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1vj01p | why is it cheaper to buy a bluray with the dvd and the digital copy than it is to just buy only a the download of the digital copy? and why is nobody else making a bigger deal out of this. | I understand that as the company selling the product it's probably similar to selling gift cards. Where they don't have any initial investment so they aren't pressed to sell off overstock, so that's probably why they don't run sales on their digital movies. But seriously why would anyone pay more money for an inferior product. You can't loan your digital copy to your friends and family like you can LEGALLY with your physical copy. You even pay a premium for the HD version opposed to the SD version.
Most importantly if the company selling you and hosting your digital copy ever goes bankrupt you loose everything you have that they're hosting. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vj01p/why_is_it_cheaper_to_buy_a_bluray_with_the_dvd/ | {
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"Physical stock takes up space. If it's not selling, the store can discount their price because they've already bought it wholesale in order to move the product and free up space for something they hope will sell better. Digital copies only take up space on a server so there's less incentive to discount them. "
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2tdqck | the abortion ban | I get that they're trying to ban it from hospitals, but does it include ALL forms of abortion? Whats stopping women from doing legal things like drinking/smoking, eating raw fish, hanging out near microwaves, etc. during their pregnancies to force miscarriages? Is it just any drug that forces a miscarriage? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2tdqck/eli5_the_abortion_ban/ | {
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"They don't understand that people who want an abortion WILL get an abortion regardless if it's safe and legal or dangerous and illegal. I'll admit that prolifers have a couple of valid arguments, but I also know that it doesn't matter. The pro-life vs pro-choice argument is solely about the morality of abortion, not about the morality of making abortion legal.",
"Nobody's trying to ban abortion except for a few anti-abortion extremists. \n\nThe US Supreme Court has determined (and the states all must follow suit) that abortion is unrestricted up until 24 weeks. At 24 weeks, a fetus becomes viable and able to survive outside the womb. This is based on the [scientific threshold](_URL_0_), keeping religion out of when life begins and basing it on medical data.\n\nAfter the 24 week cut off, abortions can be performed only for medical need.\n\n\nThis is the famous Roe vs Wade decision of 1973, that was decided by a Republican Supreme Court. This can't be changed, its done, it's a US Supreme Court ruling, and as such, the right to unrestricted abortion in early term is not threatened. \n\nWhere the abortion proponents are getting upset, they don't like abortion to be regulated *in any way* even though its a medical procedure that must have some regulation.\n\n* Some individual states have lowered their individual thresholds to 22 weeks, due to some limited newer research and some infants that have survived premature birth at 21 weeks. Newer medical research may change the survivability threshold if there becomes *substantial* new research, but it won't change the right to an abortion. \n\n* Some states have had to regulate abortion clinics that were so bad that they were disposing of fetuses in landfills and had rust on the vacuum machines. Regulating and requiring minimal medical standards of clinics makes abortion proponents very upset, but doesn't restrict any individual woman's rights to receive an abortion, and doesn't ban abortion. \n\n* The current house bill. Bills are introduced every day into Congress that go absolutely nowhere. \n\nAnd No bill, and no state can 'take' abortion rights away or ban it.\n\nOnly the most extreme pro-life and pro-choice stances don't accept the rational 1973 Supreme Court decision on early and late term. Under Roe vs Wade, women have 0 restrictions on abortion up until 'viability', then they must have medical need to receive an abortion. It's a done deal. Since 1973.\n\nThere really is no 'abortion fight'. No matter how much the far-end prolifers (the ones who are against ALL and ANY abortion) wish it to change, it won't, not without an astounding hat-trick change in medical research. No matter how much the far-end pro-abortioners (the ones who think there should be NO restrictions and no regulations) wish it to change, it won't, not without an extreme political coup rendering the Supreme Court obsolete.\n\nSo there is less of a fight that either of the far ends of the spectrum make it out to be. The extreme pro-lifers will continue to fuss but they can do nothing, and the extreme pro-choicers will continue to fuss and they will have little effect either. The US Supreme Court decision is not at risk.\n ",
"In addition to what everyone else has said, there's no risk hanging around microwave ovens. ",
" > Is it just any drug that forces a miscarriage?\n\nNot sure how accurate this is, and I'm definitely stretching relevance to your subject, but while reading up on the effects LSD can have earlier, a section from the Wikipedia page stated that the drug can cause uterine contractions. Now, would that cause a full blown miscarriage? Hell if I know.\n\nOf course tripping balls while TRYING to have a miscarriage sounds like a grade-A recipe for a really bad trip."
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396c6l | why is there such a difference, between north and south africa? | I know for the most part the economic standing of Africa as a whole is pretty bad, but I have met quite a few people from South Africa and some places seem to be doing okay. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/396c6l/eli5_why_is_there_such_a_difference_between_north/ | {
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"I think first you should realize how large Africa is, and the fact it's an entire continent...that would be like asking why Canada and Panama are different. ",
"I don't know if you mean the country or the area generally in the south of Africa. \n\nSouth Africa the country is a former British colony and is fairly well-off and developed as a result. The countries around it didn't have as many white settlers who brought and/or kept wealth with them during decolonization so they generally aren't as developed or wealthy. There is no country called North Africa.\n\nIf you mean the south of Africa generally, there's a big desert called the Sahara that separates the part of Africa that touches the Mediterranean from the rest of Africa. That's a significant geographical barrier that has kept the two pretty separate for some time. However, I don't really think you can meaningfully generalize about the state of development in all the countries north of the Sahara vs. all the countries south of the Sahara based purely on geography."
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9ul13n | how come mp3 file qualities from youtube converters deteriorate with time? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9ul13n/eli5_how_come_mp3_file_qualities_from_youtube/ | {
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"You'll have to clarify what you mean by \"deteriorate with time.\"\n\nOnce a file is downloaded to your computer, unless you mess with it, the only thing that can happen to it is degradation of the medium containing the data, colloquially called \"bit rot.\""
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3lj8k7 | this article about e-cigarettes claims 10 times the cancer ingredients, and reeks of bullshit. can someone smarter than me explain their angle here? | They are claiming e-cigarettes have 10 times the cancer causing ingredients... which doesn't sound right, but I don't know enough about it... So ELI5!
_URL_0_ | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3lj8k7/eli5_this_article_about_ecigarettes_claims_10/ | {
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"There's a bunch of people/groups running a fear campaign on vaping/e cigs. Just like 'Reefer Madness' and marijuana. They are basically hoping people will take the thing they say as fact, scare them, and either get less people to do it or somehow get it banned through legislation. Unfortunately, some people do take stuff like this as fact. Most of the time I hear someone arguing about how bad ecigs are is when they are outside a bar sucking down a cigarette and see me pull out my vaporizer. ",
"That article is definitely full of nonsense. The source is [a Guardian article](_URL_0_), which gives much more detail. The \"10 times the cancer ingredients\" is completely wrong. There was 10 times as much formaldehyde in one particular brand of e-liquid, than there is in cigarettes. But there are many cancer causing agents in cigarettes, and formaldehyde isn't even clearly that bad (your body produces some formaldehyde naturally).\n\nThe real issue here is that e-liquid is way too under regulated overall, so no one knows how safe different e-liquids are, but there are also a lot of different e-liquids, so you can't generalize like these articles claim. This quote from the Guardian article is also insightful about these misleading claims:\n\n > “Obviously, we have to realise that focusing the discussion on one of the tens of carcinogens present in tobacco cigarette smoke is misleading,” Farsalinos said.\n\n > “Even if e-cigarettes contained similar, or higher, levels of formaldehyde, they do not contain the majority of other toxic and carcinogenic substances present in cigarette smoke. Overall, any residual risk from e-cigarette use is orders of magnitude lower than smoking. This is exactly what smokers need (and deserve) to know.”\n\nI still think this quote is not great, because we really don't know the residual risks of e-liquids, but it does point out the misleading nature of the \"10 times the cancer ingredients\" thing."
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3frrbx | why is glacier preservation so important? what would happen if they were to be completely melted across the globe? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3frrbx/eli5_why_is_glacier_preservation_so_important/ | {
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"Glacier melting is seen as a significant indicator of global temperature. They are long standing, relatively stable structures. If they start disappearing, it means conditions have changed that were constant for a very long time.\n\nFurthermore, a lot of them are on land, which means if they melt they add their water to the ocean, which can potentially raise sea level.\n\nSo in and of themselves, they represent a danger, but also they represent a signal of a greater danger, global warming.",
"First, I will say, it affects so many things (WAY more than I can probably even think of).....not only the oceans currents, but also how wind is spread across the earth...how storms are generated in what places that need them (for example, the monsoon season in Asia is VERY important for crops, etc.). I mean I am not a scientist or anything, just you know have watched an absolute shit ton of Planet Earth o.o Also, if they were to melt, the polar bears would probably disappear (along with other wildlife) because when it all melted around them, they would have to swim endlessly...until drowning I assume?",
"they do two things: tie up large amounts of (fresh) water, and reflect sunlight.\n\nif they melted, the sea level would logically rise, as the water would move from the glaciers, to the seas. \n**However**, the huge, white surfaces that glaciers are would also stop reflecting sunlight, which would be absorbed by the planet instead of reflecting it back into space, futher incrasing global warming.\n\nThis would lead to even higher sea levels, as in contriary with popular beliefs, the biggest contributor to the sea levels rising are simply that water expands as it gets hotter.",
"Glacier melting changes that landscape around the glacier, causing local flooding and change of the local ecology. The glaciers reflect a lot of sunlight, but in their absence, it heats land. The melted water runs off into the ocean, changing the salinity of the water locally and affecting the sea life there (it dilutes the ocean as a whole as currents churn the water). The water also raises sea-level, which affects coastal habitats and human developments.\n\nThe amount of water locked up in glaciers is staggering. Glaciers are about 2% of all the water on earth. If they melted completely (including the polar ice caps), sea level would rise about 70 meters (230 feet). They represent such a large mass of water, that melting glaciers redistribute the weight on the surface of the earth enough to cause earthquakes (and tsunamis).\n\nMore importantly, they are a good indicator that the global surface temperature is increasing overall."
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18n909 | what am i hearing when i hear my house "settling down" or "going to bed" at night? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/18n909/eli5_what_am_i_hearing_when_i_hear_my_house/ | {
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"When you heat things they expand. When they cool off, like at night, they contract.",
"I lived in a mobile home (trailer). It was made of lots of metal, which expands and contracts more when heated or cooled. I heard lots of noises when the HVAC system came on or off. One piece of metal gets a little warmer, and moves farther than the next. Where they touch, they move a little. It makes a noise. "
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6276kv | why does travelling over hills quickly in a car cause that "lifting" feeling? | I've noticed since I was younger, when I'm in a car that quickly goes up and over a hill, at the apex, there's a "lifting" feeling. I believe rollercoasters also cause this as well. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6276kv/eli5_why_does_travelling_over_hills_quickly_in_a/ | {
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"It's because of your inertia.\n\nWhen you go over the Apex, the car changes from moving upward to downward. While this happens, your body still maintains the upward inertia. The lifting feeling you are referring to is your internal organs following that inertia upward, until gravity brings you completely back down with the car. It's subtle and quick though, so you don't lift off of your seat, unless you're going very quick.\n\nHope that explains it.",
"It is inertia.\n\nYour body has an upward trajectory as the car is climbing the hill. When the car levels off, your body wants to continue to travel upwards."
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cj8nii | why do moths wait until the sun is down to be active, yet seem to spend all their waking hours around lamps? | Why would a nocturnal animal like light so much? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cj8nii/eli5_why_do_moths_wait_until_the_sun_is_down_to/ | {
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"they normally use the moon to navigate and these lights just confuse them. It's not like they \"like\" or need the light to live."
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29yijt | how norton antivirus is still a best-selling product, despite constant negative attention from the tech community? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/29yijt/eli5_how_norton_antivirus_is_still_a_bestselling/ | {
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"Depends on what you mean by 'the tech community' \n \nNorton Antivirus used to be pretty bad - a bloated resource hog that nobody in their right mind would want. Nowadays it's actually pretty good - lightweight, quick to install, and offering pretty good protection. All of the independent 3rd party tests rate it pretty highly. There's still a vocal core of die-hards who can't / won't let go of 2005 who will insist that it's awful purely based on the fact that it used to be. \n \nAnother reason why it's a best-selling product is probably down to the deals that see it bundled free with new PCs from certain manufacturers. They'd all count towards sales figures.",
"This isn't necessary reflective of Norton's protection abilities, but rather because I work in IT on a campus where students are required to install a connectkey to access our networks. With Norton, there is often exceptions that need to be created, often those exceptions need to be updated, and it becomes a long, tedious process that sometimes works, sometimes doesn't.\n\nOften, students will bring their laptops to us and say: \"FIX IT\". Okay, we can do that, but the absolute easiest and most efficient solution is to uninstall the free copy of Norton your computer came with and put on an anti-virus that is more congruent with your network keys. \n\n95% of students and faculty say, \"Sure. Let's do that. Sounds fast and easy. Great.\" I remove Norton from their system, install something else, and everything runs how it should.\n\nThe other 5% are completely obstinate and not only do they believe Norton is the absolute best anti-virus software out there, they know this because they *paid* for it. They will not let me un-install it, nor will they accept that perhaps the issue is *not* on our end, but on theirs. Because they have a piece of software that they either paid for, or plan on paying for because \"it never caused me any issues\". Well, it has, and it *is*, and it *will*. \n\n\nI don't think Norton is particularly *bad* but I think if you're spending $40 per year (is that what it's up to?) on anti-virus software, it'd better outperform the plethora of outstanding **free** anti-virus software options that are out there. And from my experience, it simply does not.",
"Mostly from corporate. There are regulations and standards in IT security that i.e. Fortune 500 companies have to follow. Having NAV installed across devices provides a measurable level of security against malware and virii for compliance purposes. \n\nFor the majority of the individuals, it comes as part of buying a PC and upselling. ",
"Man, I've been seeing more and more threads and comments about how bad Norton is. \n\nI've used Norton for years, as a home user across WinXP, Win7, to Win8, and really NEVER had a problem with it. I've used their Internet Security package for a few years now and never get any of the problems in background usage, crashes, or random quarantines people talk about. \nMaybe I'm just lucky. It is a bit pricy, yeah, but it's never given me a reason not to trust it. *shrug*",
"It's because it comes pre-installed on almost every computer you buy. People don't want to buy anti virus so they use Nortons free trail. Their numbers are probably inflated because of this. ",
"It's fashionable to hate it so people do.",
"My guess is that very few people choose to buy it but many buy it indirectly because it came pre-installed. Norton add in these figures to bulk up sales.",
"The consumer version of norton is often sold though shere force of marketing. People purchasing computers through retail establishments are offered it as a bundle for \"free\" or sales of the product somehow kick back to the salespeople/store (this was common practice at Best Buy years ago)\n\nThe enterprise/commercial Norton product is an entirely different animal than the consumer product. If you have to manage, update and upgrade thousands of installs silently, with complete control over each systems AV settings, while simultaneously locking out the user from making their own changes, AND you want support from the AV company when you encounter problems with your configurations/deployments then there isn't much out there to choose from",
"Marketing, name recognition (a long time ago they were thought as the best even by the tech community) and making sure they are preloaded on many new pc's",
"I'm kinda surprised no one has answered this properly. The quality of the product doesn't matter, Norton has contracts with most of the major computer manufacturers to install 30 or 60-day trials of Norton on every computer they put out. Norton \"works fine\" for the first thirty days because what're the chances a standard user will pick up the FBI virus in that time and they then panic when they see it has expired and but it because the way the popups are laid out it's almost impossible not to. \n\nPeople then continue paying for norton yearly, because they don't know any better. 90% of the people that come to me asking to fix their computer is because their \"weatherbug stopped working\" and you then get to see a computer filled with more adware and rogue AVs than you've ever seen, because Norton doesn't give a shit about any of that. For the standard Norton user, those programs are just par for the course.",
"BECAUSE IT WORKS!\n\nI've had norton forever and I've NEVER had an issue. I posted that in another thread and there were a bunch more people who never had an issue. Norton is fine. ",
"Isn't Rosetta Stone the best selling language learning kit when most people recognise that it's awful?",
"ESET NOD 32.",
"Symantec is a huge company. They've bought up a lot of companies also in the last decade. In addition, they've got a lot of standard corporate solutions that even my company won't move from due to the history and pricing.\n\nSymantec Endpoint is their corporate version which runs fairly decently all things aside, and has a proper central management piece. We also use BackupExec.\n\nI'm sure we'll move away from them at some point but it's easy to stick with what's been working.",
"Most people don't understand computers, let alone computer security with regard to viruses and other malware. Since they don't understand proper security, the best solution that they can come up with is to buy a good security software suite including an antivirus. Since they don't know what constitutes a \"good security software suite\" they tend to just pick a company that they've heard of, which means Norton or McAfee. Then they tend to buy the more expensive package (full suite instead of just the antivirus), assuming it must be better than the cheaper version.\n\nThe problem is that antivirus software is almost universally bad, and what you should really be looking for is not the software that provides the most extensive protection, since \"extensive protection\" means horribly intrusive and bloated software. What you really want is something that will provide a basic level of protection while being lightweight and unobtrusive.\n\nNorton is giving people what they want-- a big bloated expensive intrusive security suite-- rather than what they should want-- a lightweight free unobtrusive antivirus.",
"It's bundled with a lot of crap. Like Conduit.",
"The same reason reality tv, Michael Bay movies and Macdonalds are popular. ",
"Norton comes on most new PCs, and the average person is nowhere near as computer literate as you would think. \n\nA friend of mine insisted for years he didn't need an antivirus because \"nothing has ever happened to his laptop\", and he's never needed one before. All you have to do is be careful with your browsing habits. After 2 years or so his PC would eventually slow to a halt, and he would insist there was something mechanically wrong with it. Or it is just worn out. He would throw it in the trash and buy a new one. \n\nHe finally saw the light when a couple of viruses started hijacking searches and formatted his HD. But this was after 3-4 PCs got tossed in the garbage. He now uses Nortons because the PC comes with it, but last time I looked at his PC he let the subscription expire about a year ago. \n\nI've had other people who didn't want to pay for Norton, but at the same time had no clue there were free alternatives out there. They would just as soon take their chances and save $50 on the license. ",
"Marketing and the right deals and connections; just look at apple.",
"Because buying this: _URL_0_\n\nLooks a hell of a lot more trustworthy than this: _URL_1_\n\nAnd even if you don't get it boxed in a shop, paying for it makes you feel it's worth a lot more regardless of what it actually is. How can something *free* be better than something you paid for, right?\n\nThat, plus the marketing of having it preinstalled on so many computers and having their name everywhere. Even this thread is marketing for them. Which would you rather install, Norton or Zubarwa? Be honest, if you're not tech savvy would you even care to check out the other one?\n\nYou'd probably go with Norton or ask someone who might know the answer, like the guy who's selling you the laptop. What does he advise, getting Norton from their shop or installing a free anti virus product? You bet he's going to sell you one."
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5s9a12 | could we bring extinct species back to study them or just to repopulate? i.e. the dodo or thylacine. | Biology | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5s9a12/eli5_could_we_bring_extinct_species_back_to_study/ | {
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"Probably not. It's depending on how much DNA we have of any of those species, if we have a surrogate to clone them, and how much we know about taking care of them.",
"Cloning is a difficult process in and of itself, before you even consider bringing extinct species into the mix.\nYou'd need several samples of stable, viable DNA from the animal of interest (it deteriorates quickly if not stored properly), so we'd need a flesh, blood, or other protein sample from a dodo that's been well-preserved for a few hundred years.\nYou'd also need a suitable host for the clone DNA. A dodo might not be so bad to find a host for; they were closely related to pigeons and doves so you might be able to implant DNA into one of those birds without it being rejected. A Thylacine would be a stretch; there's few if any close relatives, or even carnivorous marsupials still existing on earth these days, so finding an animal to host the cloned egg would be next to impossible.\n\nSomething like a mammoth would be our closest bet, but even then it would probably end up being a sort of mammoth-elephant hybrid rather than a full-blooded mammoth."
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8ygj13 | how is the universe faster than light, and what is it made of? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8ygj13/eli5_how_is_the_universe_faster_than_light_and/ | {
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"Teenagers typically grow at most 2 inches per year, or 1.60978924 × 10^-9 m/s.\n\nThe speed of light divided by 1.60978924 × 10^-9 m/s is 1.86230874 × 10^(17).\n\nSo, if you stood 186230874000000000 teenagers on top of each other, this column of teenagers would grow at the speed of light.\n\nThe expansion of the universe at enormous scales seems at first glance like it might break rules we've established for the motion of objects on not quite so enormous scales. Just like we wouldn't expect a teenager to grow at the speed of light. But if we decide from that absurdity that no amount of teenagers standing on end can ever expect to grow collectively at the speed of light, then we decide it's absurd that the individual teenagers should be growing at all.\n\nJust as the teenager grows, the space that he occupies also grows, at a rate called Hubble's constant. Astronomers like megaparsecs, so Hubble's constant is known to be around 73.8 km/sec/megaparsec. But for that teenager, let's say he's five foot tall, the space that he occupies will expand by:\n\n3.64494336 × 10^-18 m / s\n\nA much more agreeable result if we're trying not to go faster than the speed of light! And nothing is stopping you from standing enough teenagers on top of each other until their collective expansion in space exceeds the speed of light.",
"Can you clarify your question? Do you mean to ask how the universe can *expand* faster than the speed of light? Are you asking what the actual universe is made of, or are you asking about the *contents* of the universe?",
"But isn't the universe supposed to contract eventually??",
"So if we are talking about the universe, not the matter in the universe, then it is made up of spacetime. Spacetime seems kind of like this nebulous term, but it basically behaves like a weird mixture of fabric and fluid. To answer the main question, let's just focus on the fluid part.\n\nWe can think of spacetime as a pond. Though it's not fully correct, we can think of photons like ripples on this pond. The photons have to travel at the speed of light, they can't travel faster or slower, just like ripples on the surface of the pond have a defined speed based on the properties of the water. Now, say I put a pump in the water so that water is flowing into the pond. If I crank up the pump, I can get water flowing away from the pump faster than the speed that the ripples travel. Then, if I make a ripple right where the pump is, it looks like the ripple radiates away from the center faster than it would be able to regularly.\n\nThis is pretty much what happens in our universe, except replace water with spacetime and put a pump at every single point in the universe. Now, everything is pushed away from everything else (actually, everything accelerates from everything else, so that's why we can see the universe out to a certain distance, but eventually, everything will be traveling away from everything else faster than light and we won't be able to see anything besides what is immediately around us). Particles like photons are not allowed to travel through spacetime faster than the speed of light, but spacetime itself can travel any speed.\n\nThis is why the idea of warp drives is not actually a totally crazy one. If you can find a way to not move, but then move spacetime around you, you can happily travel faster than the speed of light. The only problem is we have yet to find an energy source that can produce the right circumstances for this."
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5724h7 | what happens when a commercial cuts off in the middle and another begins/starts in the middle. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5724h7/eli5_what_happens_when_a_commercial_cuts_off_in/ | {
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"Often times on national programming the local affiliate will run their own ads during the commercial breaks. The national network still runs an ad in case one of the local affiliates doesn't run an ad.\n\nWhat you are seeing is the national ad start and then the local affiliate switching to their ad just a bit later than they were supposed to.\n\nSometimes this happens during sporting events when the local affiliate only gets a few seconds of notice when a commercial is about to happen. "
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3szgnt | why (at least in the us) do they fold lunch meat the seemingly convoluted way they do in plastic packaging? (i.e. not from a butcher or deli market but from a package off shelf in supermarket) | I always have a hard time getting most meats out of their packaging only to end up with shreds of said meat. WHY DO THEY TORTURE US LIKE THIS??
EDIT: Thanks all. It's annoying that they fold it the way they do to make it look like there's more but I guess that marketing for ya. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3szgnt/eli5_why_at_least_in_the_us_do_they_fold_lunch/ | {
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"Do you mean [like this?](_URL_0_) Where the slices are kind of folded in to each other?\n\nI suspect it's because folding it that way makes for a prettier presentation, and the illusion you're getting more product compared to flat slices. \n\nI've been frustrated by this before as well. "
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c72hmt | magical thinking | I was just listening to Conan O'Brien's podcast with Stephen Colbert, and Magical Thinking was brought up. I'd never heard of it before, so I decided to look into it but can't decipher the explanations given on [this Wikipedia page](_URL_0_).
Is it simply just a line of thought where people want a certain thing to occur, so they try thinking about it to make it happen? Also, Wikipedia mentions a few feilds; anthropology, psychology, psychiatry; have different definitions for it. How do these differ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/c72hmt/eli5_magical_thinking/ | {
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"I have students who have not done any of their school work so they are flunking. They tell their families to come to graduation because they are going to catch up even when it's impossible. That's magical thinking.\n\nBasically, you act like what you want is going to happen will happen, but you don't put any effort into making it happen.",
"There was an old 'South Park' episode about the Underpants Gnomes, who sneak into people's homes and steal their underpants. The kids confront the Gnomes and ask why they are doing this. The Gnomes have prepared a business plan, [complete with a chart.](_URL_0_) It reads:\n\n1. Collect Underpants\n2. ?\n3. Profit\n\n & #x200B;\n\nThis plan is logically absurd, because there is no relationship between collecting underpants and profit. Even the Gnomes are unable to articulate their plan for generating underpants-related revenue. They literally put a question mark on their chart.\n\n'Magical thinking' is when there is no rational relationship between cause and effect. The person assumes a fortunate outcome without reason, or they assume that something they do will manifest an unrealistic result.\n\nSo for example: \"Whenever I wear my lucky baseball hat, my team wins the game.\" We all know perfectly well that the hat does not actually have anything to do with the outcome of the game, but people still show up and think that their superstition can influence the outcome. Pretty much every superstition (black cats, spilling salt, stepping on cracks) is 'magical thinking' because there is no rational relationship between cause and effect.\n\nThese kinds of examples are pretty easy to understand, but there are other examples that are a bit harder to discern.\n\nImagine you are working in a widget factory. You produce 4000 widgets a month. An accountant says, \"We can stay in the black if we just produce 5000 widgets this month.\" Well, that's great, but we only make 4000 per month. The boss shrugs and says, \"We'll figure something out.\" This might be an example of magical thinking. Does the boss have a concrete plan to achieve the new target? Or is he just hoping things will somehow work out?\n\nAnother example: Bob is the factory's best widget-maker. Your boss decides to promote him to factory manager. However, Bob will have to learn on the job and they cannot afford to provide any mentorship or leadership training. Your boss says, \"Bob is a great widget-maker, so I'm sure he will be a great factory manager.\" This may not be a valid assumption. The factory manager job may have nothing in common with widget-making, and Bob may fail as a manager despite being an excellent widget-maker. This is so common that it even has a name: \"The Peter Principle.\"\n\n(See also: Frank Grimes, Michael Scott)"
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fo8dca | why are liquor stores considered "essential services"? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fo8dca/eli5_why_are_liquor_stores_considered_essential/ | {
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"During depressing times the masses NEED their depressants. Also, how many alcoholics would fall into serious sickness or death across the globe without their “medication”. A lot more people self-medicate in this World than you could imagine.",
"Because about 6% of the population have an AUD or Alcohol Use Disorder and cutting them suddenly from Alcohol could lead to serious health problems. Alcohol create a physical dependance, and Alcohol withdrawal is one of the most dangerous one. You don't want a sudden increase of people going to the hospital, because they can't have their daily alcohol.\n\nIt's kind of sad, but it's the reality."
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6b3op5 | how do bones and other organs "know" the correct shape they should be? | This may be more like an ELI15, but how do bones and other organs "know" the correct shape they should be?
I know the easy answer is "Because DNA", and the likely answer an actual 5-year old would get is "God made it that way" (or "evolution" depending on the parents; the two are not incompatible in my head and this is not the thread for that debate) but how do the various bits know when to stop growing and what shape they should be?
There obviously must be a way, because when it quits working we get cancer - but why do everybody's femurs look more or less like femurs and not ribs or baseball bats or something?
When I write code, I can set limits (while x < 1.5 and y < 5, increment x and y) and if I'm designing a 3D print job I can measure out a 3"x5"x2" block and the computer/printer can work that out to "move so far while laying down medium" , but as far as I'm aware DNA doesn't have little tiny calipers. So how does it know it's done growing, or especially regrowing?
And how does the healing process know when to stop healing? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6b3op5/eli5_how_do_bones_and_other_organs_know_the/ | {
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"So the answer is fairly complicated and ELI15 since each cell type differentiates differently. Yes, DNA is involved. To understand this we can first ask: how do cells that have all the same genetic package exhibit different characteristics (\"phenotypes\")? It's not like the DNA of your kidneys has different base pairs than the DNA of your skin. \n\nThe answer is transcription factors and chromatin remodeling. Each cell presents only certain specific parts of its DNA for transcription into RNA and then protein- the rest is all rolled up into very efficiently packed clusters called histones. The proteins expressed determine the function of the cell, from secretion of mucous to recruitment of calcium for bone formation. With certain types of cellular signaling your cells may undergo an orchastrated reprogramming event where chromatin sort of unrolls or packs away your DNA, altering the part of the DNA exposed for copying. This is sometimes called \"differentiation.\" Additional alterations can be made to the cellular products in the forms of factors that have affinity for particular segments of your DNA- they land there and can up regulate, down regulate, or completely alter the types of proteins expressed. Transcription factors account for the incredible diversity of cellular function.\n\nLet us take the immune system for example. You start with stem cells in your bone marrow that all look and act the same and they are in maintenence mode, waiting for a signal. Upon reception of the signal, an energetic threshold is met within the cell and its exhibited characteristics progress down a set path- the cell unrolls parts of its DNA that code for antigen receptors and gene rearrangements. In the case of immune cells, a differentiated cell will never go back to being a stem cell again. However, it will continue to differentiate further through the energetic follow through of its own function- these cells must produce successful protein chains as evidence of their differentiation to be allowed by other cells to leave the bone marrow and continue maturation. At stages of success, to select for success, the cells divide certain exact numbers of times. \n\nMost organ development is very similar to the immune system where you begin with stem cells, they recieve a signal, and then they recruit parts for their needs. With no stem cells, no signal, defective genes, or no / limited parts (think diet) you won't get normal growth. So now that we've described the system, you can perhaps imagine cellular signaling at the level of a developing child, where growth hormones provide the child's cells with the signal through the blood to up regulate hair growth for men, recruitment of fat to breasts for women, etc. \n\nTo form each perfect nail bed on your five perfect fingers your fetal cells recieved an exact signal to grow for an exact amount of time and in an exact way, but to disapoint a computer scientist... there does not exist a processor capable of handling the sheer complexity of information and energy exchange. We can't model this yet.",
"Ok, so on to the next question: wound healing.\n\nWound healing is fascinating, and what happens mehanistically is similar to fetal growth and cancer. It's stem cells with that same chromatin remodeling that we talked about in my other response to this post, and in this case it has a special name: EMT aka epithelial to mensynchemal transition. This is my specialty, along with apoptosis. \n\nLet's say that you fall and scratch your knee. You have circulating lymphocytes, immune cells, that scan cells for stress signals. When your lymphocytes detect the stress signals from your damaged cells they home in and begin a positive feedback process of recruiting a kind of molecule called kinase, which recruits more and more kinase. Kinase will create gaps in your blood vessels to allow more immune cells into the region to scan for stressed / damaged cells- it is responsible for the inflammation that brings new blood and thus new growth factors to the area. These abundant growth factors are available to undamaged cells in the area so that they have both nutrients and sudden new space to multiply into. \n\nYour immune cells will destroy very damaged cells. They do this with a few different signaling molecules- probably the best known is nfk-b. Nfk-b and its cofactors remodel the chromatin of hopelessly damaged cells to unveil a section of DNA that codes for a death signaling protein. In the healthiest kind of cell death, the signaling protein will pop open mitochondria to release caspase, which chews up proteins including microtubules that hold the cell's structure. This makes the cell fold in on itself like a raisin from a grape that detaches from cells around it and moves out without tearing the membrane / releasing any toxic components. \n\nNew skin cells are born from dividing healthy nearby cells because there is space and nutrients for them- epithelial cells have a scaffolding and grow in layers. Each layer gets farther from the capillaries so they compete with each other and there is only so much room for new cells. It's the reason why with bone marrow transplants you must remove some recipient bone marrow to make room for donor bone marrow: otherwise there isn't enough growth factor to go around. This is also why your skin can heal almost seamlessly- notably an exception is scar tissue, which is just collagen matrix and doesn't need growth factor so it can grow abnormally. A second notable exception is cancer, where stressed cells that should die decide instead to route around immune cells' instigation of death signaling- this is how you get tumors. Curiously, tumor cells do fight each other for nutrients still, creating ever more agressive cells at the center of the tumor. Interesting stuff, biochemistry. "
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7b8mml | why do popular websites often change things (like font, icons, terminology) to make 'improvements' when nothing was really wrong to begin with? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7b8mml/eli5_why_do_popular_websites_often_change_things/ | {
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"Design updates to keep up with the times. You may not like it, but if you look at some archived sites from the early 2000s, it is very obvious those sites are from the early 2000s. Companies will update their sites every so often if they're at all concerned about not looking old fashioned.\n\nImagine someone from the 80s who wore their 80s high school clothes for the rest of their lives, and how outdated they would look. Same general idea, even if their old clothes worked fine."
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60nbc6 | why is it when you watch a low resolution video the sound quality seems muffled, but when watching it in hd it sounds more immersive? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/60nbc6/eli5_why_is_it_when_you_watch_a_low_resolution/ | {
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"Low resolution generally means lower bitrate (How much data is transferred per second)\n\nBecause of this when you lower the quality the bitrate of the audio is also lowered, making it transfer less data and therefore making the sound a lower quality. Higher bitrate = more data which means a higher quality sound."
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555b93 | pablo escobar sold drugs in the us, and shipped the cash back to colombia. why could he use all the us-dollars in colombia? | Why could he even use US-Dollars in Colombia, and why was it not easy to track down the usage of huge amounts of US-Dollar cash in Colombia? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/555b93/eli5_pablo_escobar_sold_drugs_in_the_us_and/ | {
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"US Dollars are good everywhere. They are pretty much the go-to global currency. Especially for black market deals.\n\nAnd it isn't like everybody didn't know Escobar was a drug lord. He didnt try to hide it.",
"US Dollars are good in many countries. Especially in Mexico, Central and South America, where the dollar is often far more stable than the local currency.\n\nHeck, in Ecuador, their official currency *is* the US Dollar.",
"I can't say what it was like it the 80's but it would be a problem in places like Europe now to use US Dollars for anything that isn't massive deals, or depositing in banks. \n\nBut dollars are welcome in Latin America (are they still?). \n\nMore to the point, he was Pablo Escobar. Plata o plomo. No need to offend the man or quibble over currency when he's buying something from you. ",
"Currency is just a medium and a piece of worthless paper. It only has value because of its financial backing. \n\nThe reason most countries and individuals use the USD is that they feel confident that the US can continue backing up (keeping the trading value) its currency in a stable and consistent manner. Most countries cannot do this and this results in the value of their currency to fluctuate. This is not a good thing at all because one day your currency could be worth a lot and the next day it could be worth as much as dog poop. \n\n\n > why was it not easy to track down the usage of huge amounts of US-Dollar cash in Colombia?\n\nIts difficult to track the USD because its paper with a serial code. The only time one could track it down is if that cash went through some type of scanner. Often the scanner would be at an atm or bank. If one is intelligent then they would money launder (literally trade tracked cash for untracked cash) or use the money in a way they know it would exchange many hands before it would enter the system. \n\n\n",
"Like many developing countries, Columbia's currency is weak and volatile compares to the dollar, euro, or yen.\n\nBusiness, legitimate or otherwise, seek to avoid this risk by trading in dollars instead. A coffee plantation would be every bit as likely to do business in dollars as a drug kingpin.",
"You and your friends decide to use Monopoly money to trade amongst yourselves for candy or whatever. \n\nThen one day one of your friends B gives this Monopoly money to one of his other friends C in exchange for candy promising him that he would give candy back later.\n\nC goes back to his other friends and trade this new Monopoly money amongst this other friend group knowing that at some point he can go back to friend B and get some candy for the money.\n\nBut friend C never really goes back to B to get candy because he can make candy but he can't make Monopoly money. \n\nSo friend C sends candy to friend B, and friend B sends Monopoly money to C.\n\nYou, your friends and B don't care because they can print more Monopoly money and still C will give candy because C for some reason isn't asking you for his candy back and storing his Monopoly money. \n\nHere's an article about hoarding paper US money and how it's good for the US\n\n\"So why do we keep printing $100 bills? As with any valuable export, we worry that if the C-note ceased to be available to foreign criminals and dictators, another paper currency would take its place. The leading candidate would be the 500 euro note, which criminals have reportedly nicknamed \"the Bin Laden\" because its compactness makes it so convenient to hide ill-gotten gains in\"\n\n\n_URL_0_\n\n\n"
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4ga9r8 | why do raspberries float while blackberries bob up and down? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4ga9r8/eli5_why_do_raspberries_float_while_blackberries/ | {
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"Raspberries hold more air in pockets in their surface as well as the cavity inside of them, and are less dense than most beverages of your choice, while blackberries are more dense, more solid concerning their center, and as such float less. Their bobbing in your gin and tonic can be attributed to the two contents of your drink; the gin was not mixed well with your tonic (or vice versa) and blackberries happened to be a bit more dense than one liquid but less dense than the other"
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3c99fw | how do muscles physically move? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3c99fw/eli5_how_do_muscles_physically_move/ | {
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"Your muscle is made of tiny things that use bite-sized cellular energy to pull themselves past each other.\n\n~~(By the way, nobody give me crap for this, please. It was the simplest explanation I could find for how ATP powers muscle cells and all that lovely stuff.)~~",
"I couldn't find the pretty GIF, but here's one that still explains it well: _URL_0_\n\nYou can ignore a lot of the technical details. The ELI5 is that your muscles are full of those things in the GIF, and when you want to contract a muscle your brain sends a signal that causes those little red things to pull the blue column in, contracting that line of muscle a teeny tiny bit. Billions of fibers like this add up to the big motions you get, like moving your arms and legs and whatnot.",
"Think of a person paddling a canoe, they dip their paddle into the water while it is stretched out in front of them, and then using power pull the paddle behind their body, carrying water with them. This is the very basic essence of what is happening.\n\nOn a deeper level, the brain sends signals to a part of the muscle cell which releases calcium particles, which help to stimulate the \"pulling forward\" motion. The filament which creates the pulling motion is called Myosin, and it pulls on another filament called Actin.\n\nThere's obviously a lot more to this, but I hope that is a good start!",
"Muscles are made up of a bunch of pockets, called fascicles, and each of these pockets contains muscle fibers, which is the actual muscle cell. Inside a muscle fiber there are long proteins called actin and myosin. Myosin really really really wants to bind to actin, but it can't because there's an obstacle in the way, which is another protein called tropomyosin. Tropomyosin wraps around actin and doesn't let it bind to myosin. However, tropomyosin has another protein on it called troponin, which tells tropomyosin to either get in the way of myosin or get out of its way. \n\nLet's say that you need to activate a muscle (like the bicep if you're lifting groceries, or the chest if you're pushing against something). You're brain sends out an electrical signal which travels via neurons down your spinal column and out to whichever muscle is being used. Once the muscle gets this signal, it releases a bunch of stored calcium, which randomly floats around inside the muscle fiber. But since you suddenly have a lot of calcium everywhere, some of that calcium will bind to troponin. If calcium binds to troponin, then troponin will tell tropomyosin to move out of the way. Without an obstacle anymore, myosin reaches out and binds to actin and pulls the actin closer to itself. This pulling is a muscle contraction. But since myosin pulled actin, it's tired now and lets go. To get more energy, a molecule called ATP binds to myosin and gives it an energy-boost. This energy-boost causes myosin to reconnect to actin and pull it some more. This process keeps on repeating until either there's no more actin to pull (which is maximum contraction) or the brain stops sending out a signal. Once the signal has stopped, calcium is stopped being released and thus there's nothing to bind to troponin. Because troponin doesn't have calcium, it tells tropomyosin to get back in the way of myosin. Myosin then can't bind to actin and the muscle stops contracting. \n\n**UPDATE:** I seem to have made a small mistake. Myosin is already loaded with an ATP molecule before binding to actin and the conversion of ATP to ADP releases the energy for myosin to bind and pull on actin. Another ATP then binds to myosin which causes it to break from actin and the cycle repeats. The gist of what I said in my original post is still correct. Myosin pulls on actin and the energy for this process comes from ATP. Thanks to /u/shalafront for pointing this out\n",
"Your brain sends a signal \nThe signal travels down the spinal cord to motor end plates\nIf the stimulus (signal) is strong enough all the muscle fibers in that motor unit contract. \n\nHow they contract: \nmuscle fibers consist of myofilaments Actin and Myosin\nMyosin attaches to actin and pulls....This is called a power stroke and occurs over and over again at many many sites \n\nNow it is a little more complicated with ATP production, calcium being released from the sarcoplasmic reticulum, which binds to troponin. Troponin then binds to tropomyosin...etc... If you want more detail I can go in depth. But that should cover the ELI5. \n \nNote: This is also only for \"long-loop\" muscle contractions. ",
"Here's a Crash Course on Muscles\n\n_URL_0_\n\nThe CrashCourse Youtube channel is like an ELI5 for many things."
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fegqw3 | why does hair product applied to wet hair tend to make your hair more glossy than when applied dry? | I know this isn't necessarily true for all hair products, but I've noticed that for a lot of hair products (like the matte cream that I use) when applied to wet/damp hair, it tends to remain more "crunchy" and shiny than when applied to dry hair. I assume this has something to do with the product trapping moisture under the product itself?
It seem odd to me though, since when painting, I can apply a glossy varnish for protection, but then apply a light matte finish to cut down the shine. I would think that applying a matte finish to your hair would keep it looking that way. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fegqw3/eli5_why_does_hair_product_applied_to_wet_hair/ | {
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"\"Wet hair and loads of your favorite product are like oil and water — they don't mix,\" says Wright. \"When you blow dry wet hair, the heat melts the product and weighs down the strands, making your hair too heavy to style.\""
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4k0eqe | what's the future of antibiotics and are we really heading into a 'dark age of medicine'? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4k0eqe/eli5_whats_the_future_of_antibiotics_and_are_we/ | {
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"Treatment of bacterial disease with antibiotics creates a selective process whereby bacterial strains gain resistance to one or multiple antibiotic drugs. At present some bacterial strains have been discovered that are resistant to almost all known antibiotics and these strains are [rapidly spreading across the world](_URL_1_). These threats have lead some to herald \"the dawn of a post-antibiotic era\".\n\nMost medical therapies such as women's health, anti-cancer therapy, molecular medicine, small molecule discovery, prenatal care, prosthetics, and many others continue to progress rapidly. Thus we are not actually entering a \"dark age\" of medicine, but we are entering an age where antibiotic resistance is becoming a prominent threat. The risk of this threat is the re-emergence of untreatable infectious diseases which have [steadily reduced as a cause of human mortality over time](_URL_0_).\n\nThe most **effective solutions** to the problem of antibiotic resistance are both research based and policy based. [They include](_URL_2_):\n\n > **1) Preventing infection and resistance.**\n > > Example: Self-sterilizing hospital rooms.\n\n > **2) Refilling antibiotic pipeline by aligning economic and regulatory approaches.**\n > > Example: Subsidize antibiotic research.\n\n > **3) Preserving available antibiotics, slowing resistance.**\n > > Example: Stopping antibiotic use for livestock growth.\n\n > **4) Developing microbe-attacking treatments with diminished potential to drive resistance.**\n > > Example: Monoclonal antibodies that direct the host immune system to combat the pathogen.\n\n > **5) Developing treatments attacking host targets rather than microbial targets to avoid selective pressure driving resistance.**\n > > Example: Therapies that prevent virulence without causing cell death, thus preventing population bottlenecks that spawn resistance.\n\nAs such constructive policies that limit total infection and preserve last-line therapies must be married to development of new drugs. The successful implementation of these policies requires considerable financial and social investment. These policies are known to be effective in slowing the development and spread of resistant pathogens. Because [much antibiotic resistance arises specifically in developing countries](_URL_1_) where health education and infrastructure are limited, the effort will also require global mobilization.\n"
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jl000 | eli: ron paul's platform and political approach. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/jl000/eli_ron_pauls_platform_and_political_approach/ | {
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"There were several very recent questions about Ron Paul. They would probably help understanding if you want to know more about the situation with him.\n\n_URL_0_",
"Ron Paul's policies can be summarized like this:\n\nPolicy #1 - Size of Federal Government\nYour life is full of rules. Some of them come from your parents, and some of them come from your parents' boss, the school. The school makes rules that your parents have to enforce on you like, \"You have to do your homework\" and \"You can only enter school when you are 6\" Your parents make rules like, \"You can't have any more marshmallows.\" Ron Paul basically wants to get the government out of this decision and let your parents make most of the rules. Now, when you become an adult, your parents become the state government, and the \"school\" is the federal government. He wants the states to make the decisions on all the decisions that the federal government is not allowed to make decisions on, which is outlined in their rule book called the \"Constitution.\" If a state wants to do something controversial like legalizing candy cigarettes, they will be allowed to. This makes all of the states different from each other. If you don't like the way one is run, then you can move to a different one!\n\nPolicy #2 - End the Wars\nImagine that your school has some of the richest kids in the city and they want all the other schools to give your school their chocolate milk, so they attack the other schools until they submit and start handing over their chocolate milk. The rich kids don't want any part in the fight, so they pay the poor kids to do the fighting. Pretty soon, your school is fighting with all of the other schools and the rich kids have to steal money from the poor kids just to afford the fight. It becomes so corrupt that no one at your school has money anymore and you can't win the chocolate milk from anybody. Ron Paul wants to stop all of the fighting and get the school to trade with other schools for chocolate milk instead.\n\nPolicy #3 - End the Federal Reserve\nAt your school, pogs are money. At least they were when I was a kid. You use these pogs to buy lunch pails and candy off of other kids. The catch is that the school made a rule that one kid (the Federal Reserve Kid) gets to make all of the \"official pogs\". No other pogs are valid for buying candy. The trouble is that whenever this kid wants to buy something, or when his friends want to buy something, he just makes more \"official pogs\" and spends them. A bag of gummy worms used to cost 2 pogs because pogs were rare. Now that Federal Reserve Kid has made so many pogs, a bag of gummy worms now costs 10 pogs. All of the kids who aren't friends with Federal Reserve Kid get ripped off and have to buy things at higher prices than they were before. Ron Paul wants to get rid of Federal Reserve Kid and stop all of the pog making.\n\nPolicy #4 - War on Drugs\nNow imagine that the Federal government has put a ban on lemonade. Kids still want lemonade, but you can no longer sell it at your lemonade stand. You resort to selling it at night on the streets. You raise your prices because lemons are harder to get and you have to pay to hire 5th graders to protect you when you make your sales. Lemonade becomes very valuable and it becomes necessary to protect your territory with sling shots in order to push out the other Lemon Lords from your suburb. A lot of kids get hurt or killed in the fighting. You have to order your lemons from Columbia since they can't be grown in the country. Many times the Federal Government stops your lemon shipments from getting into the country, so you have to raise your prices. The thing is, lemons don't hurt anybody, they just feel good, yet the federal government is telling you whether or not you can put that lemonade in your body. Ron Paul wants to get rid of the Federal laws against lemonade and leave that up to the state governments to decide. Many states would not prohibit lemonade, like California, so you could move their to enjoy your lemons.\n\nThis is just a few of his policies. In short, he wants you to make more of the decisions about what you want to do with both your money and your life.",
"There were several very recent questions about Ron Paul. They would probably help understanding if you want to know more about the situation with him.\n\n_URL_0_",
"Ron Paul's policies can be summarized like this:\n\nPolicy #1 - Size of Federal Government\nYour life is full of rules. Some of them come from your parents, and some of them come from your parents' boss, the school. The school makes rules that your parents have to enforce on you like, \"You have to do your homework\" and \"You can only enter school when you are 6\" Your parents make rules like, \"You can't have any more marshmallows.\" Ron Paul basically wants to get the government out of this decision and let your parents make most of the rules. Now, when you become an adult, your parents become the state government, and the \"school\" is the federal government. He wants the states to make the decisions on all the decisions that the federal government is not allowed to make decisions on, which is outlined in their rule book called the \"Constitution.\" If a state wants to do something controversial like legalizing candy cigarettes, they will be allowed to. This makes all of the states different from each other. If you don't like the way one is run, then you can move to a different one!\n\nPolicy #2 - End the Wars\nImagine that your school has some of the richest kids in the city and they want all the other schools to give your school their chocolate milk, so they attack the other schools until they submit and start handing over their chocolate milk. The rich kids don't want any part in the fight, so they pay the poor kids to do the fighting. Pretty soon, your school is fighting with all of the other schools and the rich kids have to steal money from the poor kids just to afford the fight. It becomes so corrupt that no one at your school has money anymore and you can't win the chocolate milk from anybody. Ron Paul wants to stop all of the fighting and get the school to trade with other schools for chocolate milk instead.\n\nPolicy #3 - End the Federal Reserve\nAt your school, pogs are money. At least they were when I was a kid. You use these pogs to buy lunch pails and candy off of other kids. The catch is that the school made a rule that one kid (the Federal Reserve Kid) gets to make all of the \"official pogs\". No other pogs are valid for buying candy. The trouble is that whenever this kid wants to buy something, or when his friends want to buy something, he just makes more \"official pogs\" and spends them. A bag of gummy worms used to cost 2 pogs because pogs were rare. Now that Federal Reserve Kid has made so many pogs, a bag of gummy worms now costs 10 pogs. All of the kids who aren't friends with Federal Reserve Kid get ripped off and have to buy things at higher prices than they were before. Ron Paul wants to get rid of Federal Reserve Kid and stop all of the pog making.\n\nPolicy #4 - War on Drugs\nNow imagine that the Federal government has put a ban on lemonade. Kids still want lemonade, but you can no longer sell it at your lemonade stand. You resort to selling it at night on the streets. You raise your prices because lemons are harder to get and you have to pay to hire 5th graders to protect you when you make your sales. Lemonade becomes very valuable and it becomes necessary to protect your territory with sling shots in order to push out the other Lemon Lords from your suburb. A lot of kids get hurt or killed in the fighting. You have to order your lemons from Columbia since they can't be grown in the country. Many times the Federal Government stops your lemon shipments from getting into the country, so you have to raise your prices. The thing is, lemons don't hurt anybody, they just feel good, yet the federal government is telling you whether or not you can put that lemonade in your body. Ron Paul wants to get rid of the Federal laws against lemonade and leave that up to the state governments to decide. Many states would not prohibit lemonade, like California, so you could move their to enjoy your lemons.\n\nThis is just a few of his policies. In short, he wants you to make more of the decisions about what you want to do with both your money and your life."
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6373yq | what do movie producers do before and during the production of of the movie. | I understand how they make movies and all, but how do they contribute to the process and what are they doing while the movie is being made. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6373yq/eli5what_do_movie_producers_do_before_and_during/ | {
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"It's kind of a running joke in Hollywood that producer can mean anything from \"basically nothing\" to \"person who influences and makes decisions about every part of the movie\" to \"person who helped fund it\" to anything in between. It can basically mean just about anything. So how a producer contributes really depends on the producer and the movie."
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7ylisu | why is there hierarchy in our society? | Why is there hierarchy in our society? Do history or historical events play a role? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7ylisu/eli5_why_is_there_hierarchy_in_our_society/ | {
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"Humans cannot exist alone. An alone primate is a dead primate. So, in pre-history, we lived in groups, whom we were mostly related to genetically, and went about obtaining resources required for caloric intake (eating food). Young men usually serves as the warriors and hunters (to prove their worth to the tribe), and in most tribal societies, children and women did the rest. The old and sick were sometimes left to die.\n\nEventually, we get better and better with doing this (think changing from picking berries to basic agriculture) so that more and more people are involved into the group, making it so that some of the people inside of the group don't just hunt or gather or farm, instead they can make decisions, provide religious roles, arbitrate disputes, and provide leadership. \n\nA lot of times these leaders **edit- not necessarily _leaders_ per se** were older members that were useful. Old men who could arbitrate disputes and lead. Old women who knew certain skills.\n\nThis also goes into decision-making. The group needs a decisive voice to make decisions. Thoughts of \"this outsider is bad, we should kill him,\" or \"this outsider will be helpful, let's take him in.\" Are important decisions that still come up today. Think liberals and conservatives on the matter of refugees.\n\nThe above bits bring up some interesting points - Maybe our willingness to follow the authority of a police officer has something to do with our instinct to listen to the grandfathers in our group from pre-history? Maybe young men are still willing to fight in war because they still want to prove something to the \"tribe?\" And maybe our loyalty to our nations have something to do with loyalty to the group of people who were related to us?\n\nAnyway, tl;dr people generally need leaders and orders to function well, so that's why we need leaders and a hierarchy.",
"Your question is a little bit of a minefield, because it taps into some deeper questions about the nature of humanity and society that are in hot debate right now. In other words, you're going to get a lot of disagreeing answers to this question and probably some downvotes. \n\n I'm an academic, so I'm going to answer from that perspective, and I'll try to shed light on why this question is so controversial. \n\nThe nature of human hierarchy is a contested question in scholarship. There was a very influential book written in the 1970s called *Homo Hierarchicus* that argued that humans are hierarchical beings *in essence,* meaning that each individual human contains the ideological wiring for their society's hierarchy. The implication of this argument is that hierarchy is not simply a social construct enforced by an elite class, it is something that all members of the hierarchy reproduce and participate in. \n\n*Homo Hierarchicus* was effectively criticized some years later on the grounds that it took human hierarchies as too static and too \"real.\" *Homo Hierarchicus* used the caste system in India to make its case, so the critic argued basically, \"Look, there is no real caste system, it's just a name we give to a shifting socio-political hierarchy.\" That means that humans aren't really \"Homo Hierarchicus\" in the sense that the first book was arguing because the kind of hierarchy in question there was a \"social construct.\" \n\nA number of recent events have made the question of human hierarchy especially fraught. I'm referring to Black Lives Matter, #MeToo, and the Trump Presidency. Although all of these have much deeper roots, they're happening at a time when society––and popular culture in particular––seems especially predisposed to postmodernism. In ELI5 fashion, postmodernism is the assumption that there *is no universal, absolute truth.* Truth, in other words, is relative to the individual or the society. By extension, good and evil also become relative. Because the movements mentioned above are happening now, and so forcefully, the very idea of human hierarchies is becoming anathema. How can there be a hierarchy if good is up for grabs? If truth is up for grabs? No one has a monopoly on those things in the postmodern world, so no one deserves to be on top. Moreover, those on top are only there because they have used their power (financial, physical, whatever) to get there. \n\nThe rising popularity of Jordan Peterson has something to do with your question of human hierarchy, I think. Peterson believe the modern, western world is attempting to undo the human propensity for hierarchy. He believes that we have been evolutionarily hard-wired for hierarchy, and that attempting to enforce equality of outcomes (men, women, and different races all have the exact same representation in different jobs, in higher ed, the same incomes, etc) will damage society because it will damage individuals who naturally exist in hierarchies. Modern society, Peterson believes, is telling people not to be active in the world because they will only perpetuate the hierarchy––and young men are getting the worst of it because, for so long, they've been on top of the hierarchy. \n\nPeterson himself has drawn a *ton* of criticism. Most of that criticism comes in the form of popular press hit pieces, but those aren't worth talking about because they straight up get their facts wrong. What's more important is that these pieces are being written and read. I think it's significant because it shows that there is a real struggle going on between people who believe that humans are naturally hierarchical and those who think that it's all social construction and we can break out of it and have equality.\n\nSo to answer your question about why there is hierarchy in our society, the short answer is \"fuck if I know.\" The slightly longer answer **seems** to be––based on the evolutionary evidence (which Peterson accurately cites, by the way) and sociological evidence––**we have hierarchies because we want them, and we want them because we need them.** We animals, and animals need biological imperatives there to keep them from killing each other all the time. Hierarchies help keep animal societies organized. But we are also *rational* animals. We get so much sensory input every minute of every day and our brain has to process it. And then we have to process that accumulation of that input. And then we have to process our processing. It's too much data *not* to categorize. We need to know who the more powerful people are in society so we can be careful of them, and the moment we know that there is a category for more powerful, we want either to fit into that category of suck up to it. Social hierarchies build off this evolutionary need to categorize and then those social hierarchies themselves become ingrained into the human brain, changing the way we see the world. \n\nI'll end on an interesting story from the set of the original Planet of the Apes. Because it took so long to put on makeup everyday, the ape actors and extras would leave their makeup on during lunch. Both the human actors and the directors noticed something strange happen every day: the apes would eat lunch with the apes, the chimps with the chimps, and the orangoutangs with the orangoutangs. No one told them to do this, they just spontaneously did it. ([source if you want](_URL_0_)). The question is, how long until those separated groups of apes organize themselves into hierarchies, both internally amongst themselves and then society-wide? "
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2bjrzm | why do movies about modern times often include outdated technology (e.g., paper & pen, dedicated camera, typewriter, etc.)? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2bjrzm/eli5_why_do_movies_about_modern_times_often/ | {
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"Paper and pen is not outdated as of yet. Many if not most still use them daily. ",
"To most adults that go to movies, neither pen and paper nor dedicated camera is \"out of date\". A huge number of people still use both every day.\n\nTypewriters are a fair example, but a large chunk of the movie-going audience doesn't agree with you at all on the other two that you include in your post title. \n\nAlso: movies take on average over a year to script, film and release. Most of today's big hits started filming in 2012, and perhaps 2013 if they didn't have a lot a post-processing special effects. So many are already two years old, if not more.",
"i don't think \"movies\", as a generality, exhibit the trait as the question implies, despite the obviously inapplicable examples.\n\npaper and pen? seriously? have you been to office depot? or to any office, or school?\n\nby \"modern\", did you intend \"future\"? if so, this is a very good question. i have no personal experience in the matter but i have read on occasion that movie-makers often spend a great deal of time and effort trying to make the movie-future contain futuristic technologies. sometimes they get it and i've seen examples of terrific fails.",
"The advantage of a single-use item on screen is that it's instantly obvious what somebody is doing with it.\n\nIf you have a wide-angle shot of somebody fucking around on a smartphone, you can't tell if they're SMSing a friend, taking/editing a picture, writing a book, reading a book, playing games or shopping for toilet paper.\n\nThings done on the screen should have an obvious purpose that furthers the story. Writing notes on paper, taking pictures with a camera or calling somebody on a desk phone tells you exactly what's going on without wasting screen time waiting for you to figure it out.\n\nIf you look into film, there's hundreds of little things going on that have this same purpose: a half untited necktie tells you that a character is off work, a baguette sticking out of a paper bag tells you their on the way home with groceries to have a quiet night making dinner, stubbly facial hair shows that they're under stress & have been too busy to shave.\n\nMovies aren't usually about accurately capturing reality, they're about telling stories and emphasising the bits that tell you what's happening in the story."
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8odah6 | my hard seltzer boasts of only having 2g carbs. so why is it 100 calories? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8odah6/eli5_my_hard_seltzer_boasts_of_only_having_2g/ | {
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"The calories stat measures everything that your body can burn for energy. \nCrabs are one source, but a whole lot of stuff can be burned for energy, even protein. \nThough I think the alcohol itself in your hard seltzer is probably the biggest contributor. \nAlcohol is a very energetic source as can be demonstrated by setting hard liquor on fire. \nYour body will actually run off alcohol if it's present before going for more complex energy sources. "
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blnwk5 | how do penguins swim faster by continuously jumping out of the water? | On Planet Earth Documentation they said that pengiuns swim faster but use more energy if they jump out and in the water while doing so. Isnt it a waste doing curves instead of swimming in a straight line? Or is the air making them faster because it has less resistance then water? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/blnwk5/eli5_how_do_penguins_swim_faster_by_continuously/ | {
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"Second one. Water is well over 700 times denser than air, so the bit of energy required to launch upwards is offset by the fact that they don't have to be constantly driving themselves forward through the water, a good portion of their travel is done through the air."
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8wg1mk | in an accident when the steering wheel airbag deploys, why doesn’t the plastic cover hit the driver in the face? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8wg1mk/eli5_in_an_accident_when_the_steering_wheel/ | {
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"There's a hinge, so it opens like a door with the force of the airbag. It's not launched at the driver's face.",
"Designed to break apart along it's seams so that it breaks apart outwards away from your face. Thankfully it seems to work well as I have taken 2 airbags to the face without any real injury."
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cjivhh | how do celebrities, like oj simpson, who lose their fortunes still live seemingly lavish lifestyles? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/cjivhh/eli5_how_do_celebrities_like_oj_simpson_who_lose/ | {
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"If you're famous, you can often get a free ride or even get paid to show up at events or parties. Plus, rich and famous people have rich and famous friends. \n\n Shit, even some no name, not rich people can live a somewhat lavish lifestyle by knowing the right people. Look at Kato Kaelin.",
"Because his income can't be touched.\n\nAs a former NFL player, OJ has a very large pension, and pensions can't be attached in civil lawsuits.",
"By becoming judgement proof. \n\nIf you expect to be sued, you can liquidate the majority of your assets and then purchase the most expensive mansion you can outright buy in a state like Florida. That state's homestead exemption, which does not let a court force you to sell your primary residence to satisfy a civil lawsuit, is very strong. \n\nThe Florida homestead exemption is unlimited. Whether your homestead is worth $100,000 or $10 million, it is protected against the claims of creditors. Otherwise, you could be forced to sell or relinquish many assets, except those with protections, i.e. pensions, primary residence.\n\nIn Tennessee, for example, the homestead exemption is limited to just $5,000, an amount set in the 1800s to protect the family farm from creditors. It is largely useless now to protect assets from creditors.\n\nIn bankruptcy, the Florida homestead exemption allows a primary residence of unlimited value to be protected from creditors as long as the debtor has lived in Florida for 40 months or more, and the property is not larger than half an acre in a municipality or 160 acres elsewhere.\n\nOnce the creditor's case or the debtor's bankruptcy has been discharged, then you sell the residence and there is all your money again. If you own the property outright, you can often borrow against it and use those funds.\n\nHowever, fraudulent conveyance to avoid a judgement is illegal. Proving that crime requires 'intent,' which can be hard to judge. In most cases, you need to make these arraignments in advance, and certainly before you are subject to a lawsuit.\n\nRules vary by state, so definitely beware of advice from the Internet."
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3o8h95 | have we halted "survival of the fittest" now people who would naturally be dead are surviving due to advancements in medicine? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3o8h95/eli5_have_we_halted_survival_of_the_fittest_now/ | {
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"No, we haven't. Survival of the fittest means most suited to survive in their environment. Ours just happens to now be an environment where those illnesses don't kill you.",
"No we've just adjusted to what is considered \"fittest.\" The environment has changed with means the environmental pressures have changed and selection will adapt. \n\nThis is why fat troglodytes who are unemployed and live in trailer parks and eat nothing but macaroni and cheese and budweiser and get their insulin from medicare and their only exercise is riding their electric scooter to cash their disability checks are out-breeding physicists statistically and therefore are more evolutionary adapted and successful. ",
"There's often confusion surrounding the word fit as it applies to evolution. Evolutionary fitness means how successfully you can reproduce not how strong you are or how long you live. For example, male Peacocks are most fit when they're bright and colorful, even though this means that it's a lot easier to hunt and kill them. So, by evolutionary reasoning we have not halted survival of the fittest. In fact, we cannot halt it, because some people will have more children and be more reproductively successful. We've just shifted what it means to be reproductively successful. So for example before modern medicine, civilization, etc. whoever had the most living children would be the most successful. Theoretically this might actually mean having less children, because then you need to spend less time and energy taking care of them. But in modern times, no matter how many children you have they'll all live, so increased fertility might be a new form of fitness in the modern era. \n\nI made up those examples you understand, if I recall correctly people actually had large families because it was almost expected some children would die. But hopefully that gives you an idea about how evolutionary fitness works.",
"I've often wondered that about fertility treatment. Obviously in the past those people who were unable to conceive, either for genetic issues or as a result of illness/injury were unable to do anything about it and remained childless. \n\nIn modern times things are different, and so are we heading towards a 'children of men' scenario due to more people having children despite issues that 'natural selection' would otherwise have prevented?"
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68dw0e | how scientists know what wavelengths are visible to different species? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/68dw0e/eli5_how_scientists_know_what_wavelengths_are/ | {
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"Two basic methods.\n\n1. They can directly measure whether the retinal cells respond to different signals.\n2. They can associate lights in different colors with the presence of food (the food is behind the door where the light is on), and see if the animal gets the signal or not."
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9lll7f | how come taking more of a drug increases the effect but doesn't increase the duration? | Title | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9lll7f/eli5_how_come_taking_more_of_a_drug_increases_the/ | {
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"The chemicals break down and release at the same rate no matter the quantity. The effect if the chemicals is enhanced my greater amount. In order for the duration to be increased, the release of the chemicals has to be slowed through a new recipe. ",
"It depends on the drug, actually.\n\nYour body has proteins that process drugs and change them around, but only so much of them. If you think of the body like a factory, then the drug is the raw materials and the proteins are like the factory workers. If the factory workers are all sitting around, then when more raw materials arrive, they pick them up and get to work. So while there's more drug in your system, it has more effect, but it gets processed away at the same rate.\n\nOther drugs, though, there isn't enough protein to process the drug. It's like if the factory has so much material that everyone is busy working. More material just piles up, and has to wait around for the workers to get to it.\n\nStill other drugs are called prodrugs, where the thing you take isn't actually the active form. The body needs to process it first. So the proteins need to convert the prodrug into something that actually affects your body, and this process can't use up all the prodrug at once, which helps spread the effect out over time.\n\nAnd to answer the question of why we don't take all drugs at doses high enough to make them last longer, it depends on the drug. It might be that having so much of the drug around in your body is directly bad for you. Or it might be that there are different proteins that convert the drug into something poisonous, but they only really start working when the other proteins are all busy. Tylenol is like this one: there are three kinds of proteins, and if the first two are all busy, then the third one really starts working, and it turns Tylenol into a poison which causes liver failure.",
"This statement CAN be true but it doesn't have to. There is a whole subfield of chemietry (kinetics) about how fast a reaction happen.\n\nSometimes a higher concentration of a substance will lead to faster breaking down of that subtance, sometimes the speed is almost constant (e.g. alcohol is apparently being broken down at ca. 0.1‰ per hour (depends on your body but not really the starting concentration )."
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2lnenu | why is abortion a religious issue? | The Bible doesn't take a position on abortion or declare whether or not a fetus is a human being. Why then is this a religious issue? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2lnenu/eli5_why_is_abortion_a_religious_issue/ | {
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"You really answered your own question here. Because the bible doesn't declare fetuses humans or not, there is debate. If it's a human, it's taking a life (which breaks a commandment). If it's not, you're not breaking a commandment and therefore it's \"ok\". ",
"The Bible doesn't take a position, but modern religious leaders do, and they're vocal about it. Many folks take their cues about political positions from the teachings of their religious leaders.\n\nPlease note: I'm *not* saying that all people take political cues from religious leaders. Just that of the ones whose views on abortion are related to their religious beliefs, it's likely that they're members of a faith that's vocal on the topic.",
"I guess you could give both a a religious and a political answer to this. I'll go for the latter. Like so many things in society it's about power and control: in order to stay relevant in an increasingly secular western world religion needs issues it can try to push on society and rally it's followers around. If it doesn't it becomes a boring social club that people only care about on Sundays. Kinda like the church of England. Or Sweden. In the end people stop attending altogether. \n\nSo abortion has become one of these issues for several reasons; one is that it can be used to construct a very easy to understand binary argument, either you're for it or you're against it. Another is that it mainly involves women's rights which have generally been a favorite of the church to focus on because they're easier to bully than men. But the biggest is probably that it involves a large scale killing of what can be argued to be human beings. If you can convince people that these fetuses are indeed humans worthy of life then you have an issue of large scale murdering, which is a sure way to upset a lot of people. ",
"The verse most often referred to when discussing a Biblical stance on abortion is:\nPsalm 51:5 Surely I was sinful at birth, sinful from the time my mother conceived me.\nThe logic in using this verse as biblical opposition to abortion is that if a human can be inherently sinful from conception, it must also be a \"life\" or possess a soul.",
"Generally religious people tend to oppose abortion more and the nonreligious tend to support it more, but there are religious pro-choice people as well as secular pro-life people. Catholics for Choice is one of the former. Secular Pro-Life and Feminists for Life are some of the secular pro-life folks. They don't rely on religious reasons for why they think abortion is wrong. I'm not sure what Catholics for Choice believe, but by definition they must think there's no good religious reason to outright ban abortion. "
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1a41sy | how does the music industry work? | Where does most of the money come from (record sales, concerts etc)? What's the split like between studio/artist etc? Why don't artists just record their stuff by themselves instead of signing for a studio? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1a41sy/eli5_how_does_the_music_industry_work/ | {
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"Artists don't sign to a studio, they sign to a label. Labels often have relationships with studios, though these days there are a lot more bands/artists financing their own recordings, who then approach a label to market their recordings for them.\n\nHere's a very basic way of looking at the different parties involved in a typical artist's career:\n\nArtist = Person or people responsible for making music.\n\nRecording Studio and/or Producer = Person and/or entity responsible for recording the artist's music, and some times creating the backing track that an artist sings to. May also handle mixing and/or mastering, though these aspects may also be handled by third parties, or the artists themselves if the artist has the skill necessary to do so. Some artists also own their own studios or employ their own producers.\n\nManager = Person who oversees and \"manages\" the artist's day to day business.\n\nPublicist = Person who manages the artist's publicity outreach.\n\nPublisher = Company that manages the copyrights and the broadcast, licensing, and synchronization of the music.\n\nLabel = Company that handles marketing of the artist's music, and often secures distribution for the final recorded product. Labels may also insist on overseeing or managing the recording process, or any of the other above mentioned aspects as well.\n\nDistributor = Company that handles the actual distribution of the recordings to retail outlets and online points of sale.\n\nThis is extremely simplified, but you get the idea (I hope). Keep in mind, the label may be the company that secures several of these aspects of assistance for the artist, in which case the label will take a larger cut of the earnings to pay for the expenses associated with them. Other times, the label may just handle the marketing and distribution. Labels usually have a direct relationship with a specific distributor so marketing and distribution are usually the areas they demand control over. An artist can secure everything else on their own and negotiate a better deal for themselves with the label, or skip labels all together, hire a manager, hire a publicist, and find a distributor on their own (a recent example of an artist doing the latter is Macklemore).\n\nRevenue can come from a number of places - CD sales, digital sales (iTunes and such), synchronization and licensing (use of a song on commercials, in movies, video games, etc), live performances (tours and such), broadcast royalties (fees paid to performance rights organizations by radio stations, karaoke bars, and any outlet that plays music, which is split up amongst artists based on who gets the most \"plays\"), royalties and license fees from people performing cover songs, and more. These various forms of revenue are split however the contracts dictate - there is really no set standard. There used to be, but these days they are all over the map.\n\nAs far as recording, the reason that artists don't typically record themselves is because it takes thousands and thousands (if not hundreds of thousands) of dollars worth of equipment to record, mix, and master recorded music to a point where the quality is good enough to be played on the radio or sold in hard copy formats. As technology improves, of course, this cost is getting lower, and there's definitely \"pro-sumer\" equipment out there that allows an artist to record themselves in a way that sounds top-quality to the average listener, but there's still quite a bit of recording and engineering skill required to get the sound perfect on all the various frequencies.\n\nThe final and perhaps most important thing to note is that, contrary to popular belief, it's simply not possible for an artist to just \"blow up\" and become successful overnight. Every artist you see or hear that seems to have come out of no where had a strong team of publicists, managers, marketing people, and a distributor putting them in the \"right place at the right time,\" even if the artist themselves were able to record a broadcast-ready product on their own (which most are not).\n\nHope this helps!"
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6exseo | why do energy drinks cause urine to turn a neon green color? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6exseo/eli5_why_do_energy_drinks_cause_urine_to_turn_a/ | {
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"Many energy supplements include a heavy dose of B-vitamins. B-Vitamins are all soluble in water, and excess amounts are easily excreted in urine. (B2) is one of them, and forms a very bright yellow solution."
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||
1lcwoy | marxist theory of exploitation | I... I just don't understand. Something about class distinction and transfer of power from some people to others? What? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1lcwoy/eli5_marxist_theory_of_exploitation/ | {
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"/r/communism101 is a great sub for questions about Marxism.",
"Fundamentally, exploitation refers to the use of another person's labour. This occurs in class society. In previous modes of production this was obvious. In slave society, the slave is forced to labour. In feudalism, the serf works part of the time on their land, part of the time on the lord's. In capitalism this exploitation is hidden under wage-labour so that it appears that we are freely selling our ability to labour. In actual fact, we are selling our labour-power to a capitalist so that the capitalist can make money. Capitalism operates under the law of value and a capitalist seeks to extract as much surplus value from the direct producers as they can get away with.\n\nWhen you work, you get paid the amount of money it takes to reproduce yourself each day (plus a little extra to get a family to contine the existence of the working class). This only takes up part of the day and for the rest of the day you are labouring for the capitalist for them to make a profit, this is the surplus-value.\n\nThere's a number of ways that a capitalist can increase this surplus value. They can lengthen the working day, they can make labour more intensive and they can introduce labour saving devices, and they can do some or all of these at a time, plus a few more tricks. This is where the liberal idea of free market fairness in regards to selling labour breaks down because inside the factory the worker is labouring under a tyranny. "
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9sdcvq | why in the us do we use voter registration to sign people up for jury duty? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9sdcvq/eli5_why_in_the_us_do_we_use_voter_registration/ | {
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"Well you have to source it from somewhere. To be part of a jury you must be a citizen, since the US doesn't really have a good database that tracks all citizens and where they live they rely on a voluntary database that requires proof of citizenship and address. There's really no alternative that won't capture people that aren't eligible. As the other poster said DMV could work, but you don't need to be a citizen to get a driver's license, so they could be wasting people's time who aren't eligible for jury duty.",
"Because it's proof that you're a living citizen. It's not even the only thing that is used to land people jury duty, so not registering to vote isn't a very effective way to avoid it. "
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203r7t | how can pulsar stars (or any other stars) become so dense? | After watching a recent "How the Universe works", where they mentioned that a Pulsar star can have a "Mount Everest amount of mass compacted into the size of a keyboard key" It got me wondering if the process is due to gravity, (such as the matter comprising the star is being literally compacted) or if it is due to the composition of the star being an extremely dense material. Or is it a combination of both? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/203r7t/eli5_how_can_pulsar_stars_or_any_other_stars/ | {
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"It is all gravity baby. Gravity is the weakest of the 4 fundamental forces and yet somehow exerts the most badassness in the universe. All that matter starts to compress and gravity forces it in further and further until there is literally a neutronic fluid. The neutrons are in actual physical contact with each other. Any further and the pulsar collapses into a black hole."
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841jy8 | when choking someone out with an arm hold; how thin is the line between turning them unconscious and killing them? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/841jy8/eli5_when_choking_someone_out_with_an_arm_hold/ | {
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"Choke holds are really dangerous, and are not something you should do casually. There's a risk of killing someone unintentionally, even if they never lose consciousness -- see the death of Eric Garner, for example."
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buhs6e | why do people "saw off" shotguns? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/buhs6e/eli5_why_do_people_saw_off_shotguns/ | {
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"Yea it's for concealing or to make it light enough to hold in one hand (but holding it in one hand is a pretty terrible idea)",
"Mostly for concealment, less weight and length for more \"urban\" uses. A shotgun is pretty long, but when using shot in close quarters, the length doesn't really add anything. So by cutting off part of the stock, you can now carry it in closer quarters, turn corners easier and still get your point shooting ability that's best suited for shotguns.\n\nAs for safety, you can basically cut down a shotgun to any length you want and it'll be fairly just as safe. They are usually chopped down to the length of the forestock, the part in front of the trigger where your offhand goes, so you can still use two hands if needed (and the recoil almost always makes it needed).",
"The length of the barrel gives accuracy, and some extra power. But you don't need that up close, at a couple of feet or so range it's going to damage something it is fired at. But it's more for threat anyway. The shorter barrel makes it easy to conceal and manipulate up close. A long barrel would be unwieldy in a crowded situation when it needs to be swung round to cover people. It could also be deployed from concealment quickly rather than walking into a building carrying a long, and rather obvious, weapon.",
"A sawn off shotgun (or ‘sawed-off’ if you live in the states, but we brits use the term ‘sawn off’) is lighter, more easily concealable, more maneuverable in close quarters and far harder to disarm without being shot (the longer the gun barrel the easier it is to push away from you).\n\nThere would be a drastic reduction in range and a slight increase in shot spread (the shot spread being more to do with removing the choke than the barrel length) but honestly not to the extent where you would really notice it.\n\nIt’s worth noting though that firing a sawn off 12 bore (or 12 gauge for our American friends) shotgun one handed will probably break your wrist. A 20 bore or .410 shotgun is less risky but also has less stopping power."
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3fe250 | why does finland have one of the highest suicide rates in the world (according to a 2015 study) when they are ranked as the happiest people in the world (2015 study)? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3fe250/eli5_why_does_finland_have_one_of_the_highest/ | {
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"When all the unhappy peoples are dead. All those left to do the survey are the happy people...",
"Currently Finland has the 20th highest suicide rate in the world with 17.7 suicides per 100 000 people.\n\nPossible reasons can be, in no particular order:\n\n1) Seasonal Affective Disorder, when the sun starts coming up in the spring, people can go a little wonky after spending a long winter being depressed.\n\n2) Binge drinking. If you develop a habit of getting drunk for the sake of being drunk, some people get all kinds of funny ideas in their head, especially after spending several days completely sloshed.\n\n3) Medication gone wrong. Can't be overruled as a possible reason. Antidepressants might keep a lot of people relatively well off, but if people start skipping on their meds, or when Seasonal Affective Disorder jumbles up their system even with the meds, or if the meds are simply just not the right kind...things can go very, very wrong and very suddenly.\n\n4) Low social cohesion. It's easy as shit to fall off the radar completely in Finland. If you don't put an effort to contact your friends, often times they start thinking that maybe you just want to spend some time alone, or that you don't want any company. So then we get in a situation where social people are well enough socializing, but the not-so-social people can be completely and utterly alone without any contact with anyone, except maybe the grocery store clerk, for days or weeks, or maybe even months. Some people might develop some funny ideas, especially if they're not the most stable in the first place.\n\n5) Recession. This one hit hard in the 90's and now we've fallen in the same crack. For a lot of people work provides a lot of their social relationships, stability, routine and purpose in life. And since a lot of jobs can be highly specialized, and the competition in the markets is fierce enough to push a lot of the possible competition out from the get-go, that means that when a factory or firm closes and you lose your job, that's it. You've bought your house, you've managed to pay your mortgage, you've built your life in who knows where in the backwoods because the company operates there and boom, shop's closed, so now you're in the middle of nowhere and you don't have enough money to get somewhere else, so you're in a dead-end town, with a degree that won't get you anywhere since there are no jobs available and you're screwed. Now if you happen to owe money to a bank on top of this, you're royally buggered. Top that with the alcohol abuse and you might start to develop some funny ideas pretty soon.",
"Other answers here are good, I just wanted to add that the 'happiest people' study is kind of a tricky study. It uses the criteria of:\n > real GDP per capita, healthy life expectancy, having someone to count on, perceived freedom to make life choices, freedom from corruption, and generosity\n\nSure, having these things would make many people happy. But I'm not sure you can really put a number on happiness. Most of these criteria make it seem like you need to live in a 1st world rich country to be happy and i'm not convinced that is the case. ",
"Well,it is because sad people died in _URL_0_ only happy people left!\n\nDownvote incoming!\n",
"Have traveled to Finland in the winter. Please enjoy your 8 minutes of sunlight. You will not have any friends in Finland unless you brought some with you. The beer there is absolutely wretched, so your only solace is hard liquor. Rinse and repeat until death.",
"Remember that Finland is also a secular country where the public view of suicide isn't as bad as in religious ones. People who kill themselves in religious countries are more likely to make theur deaths seem like accidents instead of confirmed suicides as to not draw shame of them and their families.",
"As dark as it sounds, could they be the happiest cause all of the sad people are dead?",
"The reason for the seemingly contradictory results of the studies is that they're simply studying different things. Suicides concern a tiny fraction of the population, while the happiest people study concerns everyone as a whole. How well people at risk for suicide are cared for probably doesn't move the average of happiness much at all.",
"Happiness studies look at various points of what they say cause happiness. These are usually social constructs that can increase happiness in a society. So they look at income inequality issues, health care rates and costs, unemployment, social systems for support of the poor. These all cab and do have an affect on happiness. \n\nBut to say that happiness is only a factor of the society is no fully correct. Some of these very systems that can help also can hurt. No income inequality can also mean that no matter how hard you work you can't really make a significant change between you and your peers. Social systems that make everything \"fair\" also tend to create underlying feelings of frustration for some people. \n\nIt is the way they qualify/quantify \"happiness\". You can be generally happy and have enough food, a decent job, a okay place to live, and still feel your life is shit and is going no where. You can sit during a long winter night and realize that no matter how hard you work or try and set yourself apart you will still be in the same place next year, and the year after.\n\nThere are a lot of factors that go into Happiness and Health. Taking any part of them and trying to separate single factors for them does not work. It is complex system that in many ways is not really rational. They are humans and while statistics can work to a certain point, when you get to the individual, they don't work or even tell the whole story.",
"Hi I know I'm late but its better than never, right?\nAll of these answers aren't really giving you the full picture. The scandinavian countries constantly rank among the highest in suicide rates but also the happiest people on earth.\n\nThe reason behind this is because Scandinavian countries gathers a lot of data to make statistics, more than other countries in the world in general. This gives the scandinavian countries a more precise and accurate number when it comes to data. Most countries can't be bothered to gather data when it comes to suicides and generally just release an estimated numbers, many countries doesn't even try to estimate because they just can¨t be bothered. I'm fairly sure that the rankings would be different if all countries did a proper measurement of suicide rates."
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277tdf | why do my testicles tingle when i am nervous? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/277tdf/eli5_why_do_my_testicles_tingle_when_i_am_nervous/ | {
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"I think I read somewhere once that they're trying to shrink inside you or something, to stay protected",
"Being nervous invokes the same fight-or-flight response your body goes through for any danger, for example meeting a tiger in the wild. Now imagine you are up against a tiger. Do you want your testicles right around out there where they could get snagged by a tiger claw in a fight? Or if you were running from the tiger, having them bounce from thigh the thigh while you ran also carries some risk of damage (or at the very least distracting discomfort). \nSo one of the things your body does during the fight-or-flight response is to draw your testicles up close to your body to protect them. One set of muscles on the spermatic cord contracts, pulling your testicles up close, while smooth muscle in the scrotal sack contracts tightening it up. The tingling you feel is likely feeling this scrotal tightening. A similar rising/tightening happens during sexual arousal, leading to the tingling one of the other commenters mentioned.",
"Did a radioactive spider bite your balls?",
"Science will tell you one correct answer, a magician will tell you another. \n\nThe body is made up of seven chakras, which are like non physical swirling energy vortexs. Each is as potent as the 'brain' in their functions. \n\nWhat I would be telling you is that your body is quite capable of communicating with your consciousness. Very much like a stomach grumbling. Your base chakra is the one that deals with 'fear'. It's essentially talking to your mind without words. \n\nTo deal with the situation, just simply be aware of it when it happens. Fully exhale and take a deep inhale... In that order. After that, your feelings in the situation should be much more calm and collected. \n\nScience will disprove everything I just stated. But, it doesn't hurt believe there are two sides to every story. "
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vsppx | infinite causal regress | I just heard about it and I can't see why people think it is impossible. If the universe in some way (whether the laws of physics or matter itself) is eternal, then why is infinite causal regress impossible? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/vsppx/eli5_infinite_causal_regress/ | {
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235u78 | why are right-wing political parties normally classed as the "bad guys"? | . | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/235u78/eli5_why_are_rightwing_political_parties_normally/ | {
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"It depends on the overall sway of the media in general as well as that particular country's definition of left and right wing. Human beings find it easier to understand world events if they can classify things into totally good and totally bad. Politics, an extension of human behavior is very seldom so simple. \n\nOne of the best examples is to look back at all the 20th century conflicts the US was involved in and see which administrations got the US involved and which pulled them out. ",
"Reddit is dominated by young people, who are predominantly left-leaning. Throughout history, younger generations are more liberal and older generations are more conservative.\n",
"right-wing political parties normally class the left as the \"bad guys\" "
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5fxbng | how did ancient people figure out that sex leads to kids, since the effects are so delayed? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5fxbng/eli5_how_did_ancient_people_figure_out_that_sex/ | {
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"They very earliest humans may not have known, but they instinctively wanted to have sex anyway. It would have been pretty easy to figure out after that because only the people having sex had babies. The effects also aren't that delayed. A pregnant woman will miss her period, which would be pretty noticeable, especially after the second month. It's also possible that humans would have figured it out from watching animals for hunting and observing their mating cycles (or from domestication of animals, but that came later).\n\nHowever, the exact mechanism remained unknown for some time and there were all sorts of misunderstandings about reproduction in the ancient world. For example, the ancient Greeks thought all inherited traits came from the father and a lot of medieval Europeans believed that a woman had to orgasm to get pregnant, etc., but they all knew that sex lead to babies.\n\nEdit: I should say, there is no way to know for certain because we don't have records from that time. We can speculate based on some of the artifacts that exist and what humans would have been able to observe, but will never get beyond that without a time machine. As a result, I don't mean my answer to apply universally to all groups of humans. It's meant to explain how many groups could have figured it out from a number of ways. That's not to say every group did because, once again, we cannot know. It's pretty well accepted that people had made the connection for the most part at least 12,000 years ago, but it could have been far earlier.\n\nEdit 2: One problem with this question is what it means to \"know\" something. Some people today don't know that sex leads to pregnancy, but I wouldn't say modern people don't know that. It's very likely that there were quite a few people throughout time that thought sex didn't lead to pregnancy. It's also likely that some early humans suspected what was going on, but couldn't confirm it or weren't believed by others. And of course some groups of people figured it out before others. ",
"They observed animals. They noted that women who did not have sex did not get pregnant. Some Neolithic art can be interpreted as showing that they were aware of the relationship. But we can never know for sure.",
"A related r/AskHistorians post [points to the domestication of pets, mainly dogs, as the point in time and chief reason for this.](_URL_0_)\n\nTheory goes that by observing the much shorter gestation period of animals, early humans made the connection to their own behavior.\n\nHowever this theory is hotly debated and it's not necessary to have domesticated animals to observe their biological behavior in this regard.\n\nIn any case whenever this discovery happened, it's too long ago to say with any certainty how it happened.",
"There is a decent correlation though (only people and animals that had sex ever got pregnant). \n\nMost did figure it out, but not all. On a few Polynesian islands where some of the staple foods have a very mild contraceptive property, the link was never realized (this led them to be among the most sex-positive societies ever). I think they believed in reincarnation so they thought pregnancy occurred when a spirit of someone crawled into the woman and a body started developing. \n\nOn the other hand, there were some cultures that believed that once a woman was pregnant, every man who had sex with her contributed material to the baby and were therefore partially responsible for it.",
"Fun Fact, there are still tribes in New Guinea that don't believe that sex leads to pregnancy, and it leads itself to animal husbandry being the root of our understanding of sex = kids. \n\nThe tribe tends to have very... open relationships as a result as sex is simply something that feels good and creates bonds. They believe that pregnancy occurs when spirits from the forests find their way into the bodies of women around the time of their menstrual cycle. \n\nThe reason it lends itself to animal husbandry being the link is that New Guinea tribes don't have any domesticated animals. They are purely a hunter/gatherer setup. As a result, they most likely don't have a firm grasp on the results. ",
"For the person carrying the baby, the effects really aren't very delayed. I imagine that it didn't take women long to learn to recognize the patterns of pregnancy.\n\nMorning sickness was probably a woman's first sign that she was pregnant, followed by her lack of a period, cramping, and other regular menstrual symptoms. The connection between sexual activity and the start of her body dramatically changing wouldn't take too long to figure out. \n",
"Did you just read The Wise Man's Fear? Ha. I know he got some flak for writing a tribal group that didn't understand this.",
"Theres a pretty good fiction book called \"Clan of the Cave Bear\" that I think did a decent job of explaining our best guess at early human and neanderthal culture and interaction from a first person perspective. Its a fascinating look at skills and knowledge we've lost, and how far we've come as a species since the hunter/gatherer days.\n\nThe main character spends a while logically working through child rearing and what must be necessary, in the face of what their traditions dictate.\n\nGood book, worth a read. But again, its historical fiction, so its really just a good guess.",
"Many probably didn't. I remember as an undergrad reading about a tribe of people that had an abnormal amount of albinism. It was especially peculiar because the tribe in question regarded albinism very negatively. You were a second-class citizen. So some anthropologists went to figure out how and why they had such a high rate.\n\nWell it turned out that when the men went off hunting, sometimes for days at a time, they left the albino men at home because they weren't really men. You can guess what happened from there. So the anthropologists asked them how babies were made. They were made, according to the tribe, when a woman goes down to the river fetch water. An ancestor spirit inhabits her belly and a child is born. The anthropologists, being bad anthropologists, told them how babies were really made. The tribespeople laughed at them, saying in effect \"We have sex all the time! There would be thousands of babies if what you're saying is true! No, it's ancestor ghosts.\" \n\nAnd thus many more albino children were born to that tribe.\n\nEdit: Since this thread is locked I can't respond to people. I honestly don't remember the source except that it was in one of my anthropology classes. This was ~2002. It's just something that stuck with me. People seem to have marshaled evidence that the story is anecdotal (to the field of anthropology) and so I'm inclined to believe them.",
"Ancient people?\n\nThere are people in the United States **today** that don't understand that pregnancy **can** be caused by sex. There are some people who don't understand that the \"white stuff\" from a penis if it gets into or near a vagina can lead to pregnancy. ",
"I feel like this was something that they probably didn't notice for a long time. Paying attention to nature around them and how other things reproduced they may have eventually gotten the sense that hey we can do that too. As far as the details on how this happens, we needed to prioritize our time to be able to study the biology behind it. This couldn't have happened without the idea of bartering I suppose. Someone who was a higher power had to say I will give you food if you are able to figure out how this works. ",
"The effects aren't that delayed. You have sex and within a month you get morning sickness. This is common among other women and it leads to a baby. \n\nHumans have also been selectively breeding animals for a very long time. We like to think of our ancestors as being stupid but for the last several thousand years they were just like us. they thought like us, could notice patterns like us and could attribute cause and effect. ",
"I guarantee women figured out they were pregnant without that much delay.....\n\nEspecially if they could relate to other women who had felt the same and then had a child. ",
"2 weeks is a huge delay?\n\nFirst skipped period is 2 weeks from ovulation, it isn't that hard to work out if the women of the tribe can count.",
"\"Have you ever noticed how lady grog who don't sleep with me grog not have baby? But when lady grog do sleep with grog sometime she have baby.\"",
"They would never not have known. Primate social structure is organised around this. \n\nThere's a nice but untested hypothesis that women's subversion of the natural signal of fertility (menarche) using red ochre body paint might have been the original 'word' - the trigger for the rapid escalation in hom sap's capacity for processing symbols.\n\nI like the idea it all kicked off with a dab of lipstick.",
"It really is not that confusing. Especially since there are animals with shorter gestation periods to observe.",
"In \"The King Killer Chronicle\" series by Patrick Rothfuss, there is a matriarchal society of people that think women just make babies on their own. And they laugh at the other cultures, \"You're men are so convinced they must be the center of everything that they even need to be involved in the creation of life.\" I'm paraphrasing. But they so freely have sex with each other that they can't witness the \"women who don't have sex don't get pregnant\" phenomenon. The only time a woman doesn't have sex is if she's sick or too young or too old. I thought it was really cool. r/KingkillerChronicle ",
"This is actually a very thought provoking question and a little mind blowing the more you think about it. I believe in modern society we have a tendency to be overly analytical in our approach to the unknown as we have reached a point where knowledge is free and we need only ask. In ancient times, knowledge was experiential, resulting in a much more connected and instinctual relationship with their fellow man and nature as a whole. \n\nI would venture to say that perhaps they didn't quite understand the exact mechanisms of breeding but they \"got it\" on an instinctual level. \n\nWe've certainly lost touch with much of our primal survival instincts in a busy world with self inflated pressures and a constant bombardment of white noise demanding our attention and resources.\n\n/rant\n\nEdit: few words here and there (and everywhere)",
"The menstrual cycle probably was a big clue. Women bleed every month, they have sex, get prego and relatively soon they stop bleeding. Then a short time later start getting a baby belly!",
"With #2 I started getting morning sickness and supersonic smelling abilities 5 days after he was conceived. The effects are not that delayed.",
"I want to provide a counterpoint to a lot of the posts saying \"humans would *simply* observe it\" or \"women would just remember they had sex three months prior\". The \"pattern\" for pregnancy is an extremely difficult one to recognize and most humans would not casually observe this and it was most likely one or a few isolated discoveries then spread as knowledge. Most of the posters calling this 'simple observation' are not looking at this objectively due to their current knowledge and overestimating human pattern recognition over extended time. Let's look at what it would actually take to make this connection and why it's so hard:\n\n* First of all you have at most n=1 chance every 9 months to recognize let alone confirm this pattern in yourself. \n\n* Second, the cause (sex) happens many times more than the result in a semi-random pattern, so if anything the obvious \"pattern\" is sex = no result. \n\n* Third, the time gap of a few months makes it incredibly hard to make the connection, even harder if we're talking about pre-calendar civilization. Without looking or thinking of the date do you have any idea what you did 3 months ago? You're overestimating our ability to recognize patterns over time (without deliberate experimentation). For example, until the recent public education about Celiac's disease there have been thousands/millions of *modern* humans that live for years with this disease, a disease with severe symptoms that appear *within a day* of eating wheat, and could have been cured merely by recognizing a simple pattern. \n\n* Fourth, we have to acknowledge competing explanations. Supernatural explanations and other theories could further cloud pattern recognition. A simple illustration of this effect is millions believed masturbation caused sterility into the last century despite being easy to recognize this pattern is not true at all. Ubiquity of pregnancy lore in ancient civilizations would likely derail the pattern recognition process before it began for many. \n\nA few made this connection but my point is most humans miss obvious patterns with more than a couple hours' delay like this example. And when you multiply the time scale by 90x days *plus* obfuscate the pattern with a high pregnancy failure rate with sex (lots of sex with zero result) *plus* make this pattern only testable about once a year you have a near impossible pattern for any human to casually recognize. \n",
"My grandfather used to counsel couples who would be quite upset that they couldn't have kids. He'd end up explaining the birds and the bees and they'd get pregnant, no issues. ",
"Our brain capacity has not changed materially in 195000 years, and behavioral modernity 50000 years ago. They may jave had less social experience, but they were capable of the same leaps in logic we are. Imagine how smart the first person to think up the bow and arrow was! Like their tesla or steve jobs or alan turing!!\nThey were also extremely plugged into nature. Look at domesricated animals. They had to selectively breed these to yield tamer more useful animals. Plants as well.\nThey would know how to grow a population, and instinctively be driven to do it as well.\n\nEdit: sausage fingers and smart phone",
"I'm guessing they never had to figure it out as it's kind of animal instinct. Kinda like how we didn't have to sit and figure out that water quenches our thirst.",
"In some cultures, the relationship between sex and children wasn't explicitly known. The most documented example is in the Trobriand Islands, where pregnancy was believed to be due to an ancestral spirit entering the womb:\n\nFrom wikipedia (_URL_0_): For example, the real cause of pregnancy is believed to be a baloma, or ancestral spirit, that enters the body of a woman, and without whose existence a woman could not become pregnant; all babies are made or come into existence (ibubulisi) in Tuma.\n\nThis explained why having sex didn't ALWAYS create a baby. This may also been reinforced by the fact that sometimes babies look like grandparents or other distant relatives (\"Oh, he's got Uncle Jeff's eyes!\").",
"Quite easily actually. Women who had sex suddenly didn't have periods shortly after (not anywhere near as delayed as you think). They also would possibly figure it out from hunting smaller, faster breeding critters. People were in MUCH smaller groups than nowadays (possibly 10 vs millions like today), so it was far easier to notice things happening. Good chance there were fewer females in groups than men as they leave to go with their mate's tribe. \n \nHumans were also much smarter than we give them credit for back then. They were smart they just weren't AS smart as today's humans. Look at rats, pigs, dolphins, and dogs. They all figure things out through process of elimination, cause and effect, and trial and error. So they would realize that the women not having sex didn't produce kids, and the ones that did have sex had offspring. \n \n We were also more simple minded ages ago where instinct and such took over. So, like we naturally knew to have sex when a female was in \"heat\" like all other animals do we may have very well just known that that equals babies.",
"There are a few examples of tribes (some existing today I believe, like in Papua New Guinea) that have a cultural \"block\" on understanding that sex -- > pregnancy. In other words, they have a fictitious cultural/mythical explanation that actively prevents them from seeing the truth.\n\nHowever, *most* human groups dating back at least to the origin of language would have had a basic understanding that sex leads to pregnancy - partly from observing animals (and later, through animal husbandry and controlling breeding), and partly from self-observation.",
"Babies come out of the vagina. Sex happens in the vagina*.\n\nObviously the answer to your question is more complicated than that, but I think that's a good place to start.\n\n*Well, reproductive sex. But I'm guessing that most of the sex humans have had, historically, has been this kind of sex.",
"I'd just like to point out that ancient people weren't *stupid.* In fact, they were just as clever as we are! And they had the same kind of instinct to be curious and learn things. All it takes is one woman noticing that, after having babies continuously for years, ceasing to have sex resulted in them stopping, and asking if anyone else ever noticed this, to get something going.\n\nA problem is that things can go wrong with this process due to sort of reverse confirmation bias - if you don't already have the belief that sex can cause pregnancy, but believe in some other religious explanation, you won't properly judge the evidence. Nevertheless, it can still be done, because the evidence is there.",
"I can think of a few different logical ways to discover it.\n\n- Women have babies\n\n- The babies usually resemble a man in the tribe\n\n- The man the baby resembles is always one the woman had sex with\n\n- Therefore the baby comes from the man having sex with the woman\n\n-------------OR------------\n\n- Most women have babies\n\n- Since Linda's favorite partner died Linda stopped having babies\n\n- When Linda found a new partner she started having babies again\n\n- Being with a partner must influence babies\n\n------------OR--------------\n\n- Penis goes in vagina\n\n- Baby comes out of vagina\n\n- Sex and baby linked because they are the only two things vaginas do\n\nYou get the idea. Remember, just because ancient people were \"primitive\" and less technologically advanced doesn't mean they were stupid or lacked reasoning skills. They found ways to predict the seasons, came up with basic medicine, created tools. They were still human. ",
"I want to know how and when they figured out the penis went inside the vagina to begin with",
"I tried finding a source for it and i haven't been able to so take this with a grain of salt. But i believe some australian aboriginal tribes never linked sex to having children. Sex was just something as natural as drinking or breathing. So getting pregnant might aswell have happened from these activities. ",
"Im more interested in how they handled the process of child birth without medicine. Did the just chew off the umbilical cord or tie that shit in a knot??",
"Lol our ancestors didnt magically appear here on Earth and had to figure out how everything works. Evolution my friend, you should look into it. ",
"Some remote tribes still don't actually know how it works. There's a matriarchal tribe that thinks she has to have sex with strong men thruout the pregnancy to actually form a baby. For all we know the women could be trolling the men but maybe they really think that. Or it started as a troll that has since been accepted as true by those people.",
"I have no idea what all this \"sex\" stuff is... but i can tell you how it works. First a woman will make a request to have a child. Soon after making the request, a stork will appear and drop the child off on the doorstep. However due to bad weather conditions in the past, storks have been stuck in china and india for a while.",
"I'm just talking out of my arse here so please correct me but wouldn't \"we\" already know what sex is? Since we evolved from other species and those other species already knew how to have sex, we just kinda \"knew\" it from there? Like, I'm sure the ancient humans knew they had to pour water down their throats when they were thirsty. You just \"know\", right? Because it's been like that since forever. \nSo the earliest humans also just knew what to do to have babies because their predecessors did it and that practice was passed on to our ancestors. \n\nAm I crazy or what?",
"woman is virgin, hasn't been with man, and doesn't have kids.\n\nAs soon as woman lays with man, she has kids soon after.\n\n",
"Many African and Amerindian cultures still hadn't figured it out by the time they were contacted by westerners in the 15th to 19th centuries. I know that asian cultures knew long ago.\n\nIslamic culture also knew long ago because the prophet Mohammed was asked about it by his men. They wanted to know if they should use the pull out technique when raping their sex slaves because they were afraid it would reduce the price they could be sold at if they were pregnant. \n\nMohammed basically answered that allah will decide when a baby should be born so you should always shoot inside your sex slave.",
"Early humans were primitive, but they weren't mentally defective.\n\nThey had pretty much the same brains which led us to quantum theory. They discovered things the same way scientists today discover things. Observation, theorisation and experimentation. Experimentation, in this instance, being the most enjoyable part.",
"I remember learning in different religious/classics classes that phallic symbolism and worship was big in ancient times because erectile dysfunction was much more common when the general population was constantly exhausted by manual labor and malnourishment. Instead of whiskey dick, they had insufficient-macromolecule dick, so it wasn't as if everyone was humping like bunnies. Plus, assuming monogamy wasn't a later development, a couple incapable of having sex would be observed to have no kids.",
"The question makes it seem as though modern humans just sprang into being one day and then had to learn about themselves. Sex equaling children has been a part of life on earth LONG before we evolved into this modern version of humanity. It's deeply encoded in our genetics. There was no need to learn what evolving from our earliest proto-simian ancestors had already taught us.",
"Why should they even care? First, it's part of all animals programme to reproduce. So they simply did it. Do you thing a cat is thinking of that? There is just \"that feeling\" and so both mate and things happen.\nSecond, sex does not always lead to pregnancy. It'll only work for like six days or something in a cycle of 28 days. So you can have intercourse for like 20 days and nothing will happen (because sperm survives for some days quite well). So you won't know that you got pregnant because of the intercourse.\n\nAnd that's where superstition occurs: since they could not really know what exactly was going on, fertility gods were invented. It was some gods will, that the woman became pregnant. They started to sacrifice stuff in the wrong believe that this would lead into pregnancy.\n",
"Our ancestors were equally smart as compared to modern humans, they simply had less knowledge. Most people assume that \"cave men\" were dumb, but this isn't the case at all - it was simply more difficult to transmit knowledge effectively between generations so there was no semblance of progress for a very long time.\n\nSecondly, why do you assume that ancient people made this correlation? We are naturally biologically driven to have sex and will do so whether we realize what the effects are. It is not necessary to understand the effects to actually have sex and hence have kids.",
"The better question would be: How the heck does every culture worldwide figure out how to create some sort of bread, and alcohol? Think about the steps you need in order to make bread starting with smashing seeds from some plants into powder.",
"Somebody just read A Wise Man's Fear. I think the delusion there happened simply because of how promiscuous the society in the book was. In a normal society the cause and effect is pretty obvious.",
"They didnt have to figure that out in the 1st place - all they needed was the same natural urge to have sex as every other creature. Babies followed.\n\nThat said they were about as smart as modern humans, had a natural understanding of cause and effect, and probably thought about sex a lot, just as we do. Knowledge of how to make babies followed.",
"U can ask kids currently in high school this question, there are at least two or three that still dont know!",
"thinking about evolution you have to assume that humans didn't always have the brain capacity that they have today, or even that which they have 10.000 years ago. Yet they still made plenty babies. \nOne way to look at it (although this may be more 6 year old level) would be to look at dogs. When a dog sexes another dog does that dog know it is going to make babies? well we really don't know if the dog knows because we can't speak to dogs. Using this example in ancient peoples, we can assume that at some point they may or may not have known that having sex made babies, but we can't know for sure since we can't talk to ancient peoples. What we do know is that at some point in history, humans gained the conscious ability to recognize sex as leading to babies, I just can't tell you when or how they figured it out and neither can they.\nAll living things reproduce and i don't think its really matters to that thing whether it knows whats happening or not. \nTL:DR maybe they did know, maybe they didn't. reproduction is a basic, primal instinct for survival.",
"Ancient man in the age of hunter gatherers wasn't the stupid stereotypical cave man we make him out to be. They had astute knowledge of the nature surrounding them (obviously not down to chemistry/physics level) but certainly enough to survive and thrive. They'd have to know which mushrooms were good and which were dangerous, they'd have to know about scents and tracking. They learned how to cure hides, make tools, make clothes, prepare food etc. \n\nIf they truly were as dumb and unintelligent that we make the error of thinking, we'd not be here to talk about it.",
"Define ancient. There's no evidence that 3,000 years ago people didn't have the same brain capacity we have today. They just didn't have the facilities we have today which leaves time to exploit that capacity. \nThey would have been able to observe the natural world, separating bovine bulls from cows to avoid territorial defense injury to livestock would have made it obvious for example.",
"Ancient egyptions had their own pregnancy tests\n\n_URL_0_",
"I haven't read it, but my wife read a book called Sex, Time and Power: How Women's Sexuality Shaped Human Evolution and it is pretty much entirely about this: _URL_0_",
"Keep in mind that women have a period every month. If you have sex and suddenly no period, and then a few months later there's a baby in there, it doesn't take much to know. \n \nAnimals just know. Their body changes, chemistry, hormones, etc.\n \nYou didn't have a bunch of Neanderthals suddenly come to the conclusion one Moonday around the fire as they sucked the juices of fermented fruit. They would have came to that conclusion 100s of thousands of years ago.\n \n\"Hey Thog, I think your life partner Thuga might have a baby.\" \n \n*sips shitty-tasting fruit juice*\n \n\"Yes I know, she's had cravings for squirrel stew every night this week. Which sucks because squirrels don't even fucking live here.\"",
"Along these same lines, how did they figure out semen was to blame? \n\nThere are records of ancient condoms made from various animal skills going back as far as ancient egypt and early japan.",
"I see a lot of people say they would just \"observe\". These are the same people who \"observed\" the idea that killing virgins made their crops grow. Sure, they were finding patterns (the brain is a super powerful pattern recognition machine), but bad ones. And a \"sex now, baby 9 months later\" has such a latency it might take a while to figure out that pattern.",
"We don't really have to guess with these things, stone aged people have survived into the modern day and anthropologists can just go ask them. As others have mentioned, there is a practical connection between a woman being married (in this case my not ELI5 definition of marriage is socially sanctioned sexual access between two people) and getting pregnant. When most women whose husbands die don't get pregnant and most women who haven't been married off don't get pregnant, most groups eventually figure stuff out. Hunter gatherer societies are not a sexual free for all even if the rues are different, we are talking about modern humans here.\n\nBeyond that, what makes you so sure people always did or do figure out the connection? Knowing that isn't necessary for life to go on. the Trobriand Islanders in Papua New Guinea, for example, traditionally don't believe that sex leads to pregnancy, they think a spirit is the reason why. They eat lots of phytoestrogens that act like natural birth control so the practical connection was less obvious. It's possible lots of groups of ancient humans didn't realize sex led to pregnancy, but I personally think it's likely that most did know to some extent, but there still may have been some magical beliefs mixed in (like women only become pregnant if they are married AND the village shaman performs a fertility ritual etc). I know a few groups with ideas like that from some undergraduate anthropology classes.",
"The same way you do, someone told you. All it needs is one person to have the idea that sex makes babies and then that idea can be passed on. Primitive people did not need to individually work it out from first principles - it's quite insightful to have the idea but trivial to then pass it on.\n\nIt's also ultimately testable - only people who have had sex have children. And the kids look like the two people who had sex. ",
"More curiously, how did early early man know to to stick his genitals into a woman's void. I mean, if you had a Blue Lagoon like scenario with a boy and girl living on a deserted island all their lives with no grown ups to guide them, would they naturally figure out that it was okay to stick a penis in a vagina.",
"Not only that they also observed that once they started living in cities and had an all on all sex orgies, they noticed they get STD and have a lot less children as a result... and that is when marriage was invented for STD control.\nOr so I have read somewhere, but it makes sense...",
"The most plausible thing I ever read supposed that women most likely knew about the connection between sex and children before men. And maybe knew for a very long time, possibly only revealed to each other after a certain (old) age (think mid-wives).\n\nAt that point in our history we were almost certainly tribal. Children were viewed at that time as being members of the MOTHER's clan/tribe. Children came from a woman, the woman comes from a tribe... Not so much an issue for intra-tribal relations, but one of the ways we evolved into societies was by swapping women between tribes (for the purposes of creating a pact/peace between neighboring tribes). We can see evidence of this practice all throughout our history right up until today (royalty from different kingdoms marrying to benefit both, arranged marriages, etc). \n\nMen probably didn't sort it out for themselves until the domestication of animals, maybe sheep or some other animal which required all day tending. Even then it probably took a couple centuries of sitting around watching the animals before they put 2 and 2 together (just joking on that part!).\n\nOnce men did figure it out it most likely changed the entire dynamic of society. Once men realized they were the \"cause\" of pregnancy, they almost certainly took control of it. Think dominance over women and children, because now wives and children as viewed as property, i.e \"belonging\" to the man who impregnated the woman. Now not only did the children belong to the MAN's clan/tribe, but so did the woman he made pregnant. \n\nThis would around the time different cultures started practices such as locking wives in the home, covering women head to toe, and restricting their ability to be in public (so as not to temp other men from stealing what is theirs).\n\nWhat do y'all think?\n\nEdits: clarify some points, eliminate some cruft.",
"If I were to make an educated guess, it was when we stopped being hunter gatherers. Understanding the relationship between planting something and having it grow (a view of reproduction for probably 2000+ years) is a huge leap in terms of scientific understanding.",
"If I understand evolutionary theory correctly, shouldn't humans have figured out how to reproduce (and to, like, generally survive) before they evolved into humans?\n\nLike, did this question ever come up during hundreds and millions and thousands of years of evolution?\n\nNow, I don't know a lot about science (I don't know much of anything, tbh), but does the OP's question assume that one day, out of nowhere, ancient people appeared on this earth? Like, Men, women and babies? \nAnd just another day the men and women started wondering, where the fuck the babies came from?\n\nIs that the question? Did I understand it right? And if yes, what are the implications? Was their first question really about the babies?\nWouldn't they first question the very nature of their existence? Like, where they come from and why they even exist? \n\nI don't even know where to start....\n\n\nTL;DR: assume that, like, I guess, all successful species on this planet ancient people were already the result of a time-consuming and arduous process of developing from a single organism that had only one goal, survive, through adaptation and reproduction.\n\nFucking for your life was already hardwired into peoples brains. All ancient people had to figure out was how to lie about what everyone knew they wanted anyway.\n\n\n\n",
"Ancients may be more clever than you think. They also had a contraceptive crop [which was so popular it went extinct](_URL_0_). There's also their obsession with the sanctity of female virgins, and I imagine they would have been quick to notice that temple virgins never got pregnant if they didn't know already.",
"This line of thinking about animals always confused me. Dogs, cows, etc. don't mate in order to have babies. They mate because their hormones demand it and it (sometimes) feels good. They figure it out by trial and error. Male dogs will hump almost anything, it's isn't because they want a baby couch-dog. The urge to mate is so strong because evolution demands progeny, and abstinence *is* extinction. Humans are the only organism that \"knows\" that mating now will lead to offspring later. As for when early hominids realized that, it was probably around the time they could be classified as \"people\".\n\nEdit: Why does everyone think that prehistoric women regularly observed periods or had some idea of the length of a cycle? How often do you think a bonobo or chimp has a period? They are receptive - > males find them - > pregnant. This was not a feminist society where women chose not to have sex for long periods (no pun intended). Life expectancy was low, infant mortality was high, and pregnancies were nearly continuous if the mother was healthy.",
"Off topic, but an interesting aside, the Egyptians thought the brain was useless, they thought the beating heart was the source of our body. They saved the heart in a container with other organs, they picked out the brain and did not save it during mummification. \n\nSeriously blew my mind. Like, how would you know! Gave me a new perspective. ",
"I would guess that modern man just knew from the get go, as in knloage passed down from our our parents that were lower lifeforms, depending on your definition of knowing it or being driven to do it like the lower forms of life we evolved from. That Is if you believe in evolution, if you don't the answer is definitely we got the information from being coerced by a talking snake to eat a spooky forbidden apple. ",
"It's tough to judge from our perspective, but I feel like it's not really rocket science to put this together. They would see where babies came out, and they would have known what happens when a man has an orgasm, so there are some good clues there.\n\nAdded to that, there IS a pretty immediate effect in that a woman would stop menstruating shortly after getting pregnant, and then eventually get large and then give birth.\n\nI suspect as soon as humans could do some basic problem solving, they would have understood what was going on.",
"It was a part of their culture and instinct. At the very least you could say it was a passed on behavior as it is with animals. So there was no 'figuring it out'. \n\nI'm shocked that the top comment right now is that we had to observe animals to understand. That just does not make any sense at all. ",
"I think it would be one of the first things discussed and 'known' in the sense you mean after the development of basic communication. I think communication is a key here because it is how you become aware of things across generations and space which you don't directly experience.\n\nAnother factor I would say is tribal living. In tribal setting you know everyone and hear things about people. It's not like you frequently would see pregnant strangers, which would be harder to notice a pattern with since you have no context. You spend all your time with the same women, one grows boobs and spends time with a male and then she has a stomach and a baby.",
"What I want to know is when was it that they said oh hey these parts go together? Or was it more instinctual thousands of years ago? ",
"Interestingly, in Patrick Rothfuss' *Name of the Wind*, there is a society that considers itself to be much more advanced than the rest of the world. Despite this, they don't believe that sex leads to pregnancy. They call fathers \"man mothers\" and consider them a silly superstition of the barbarian world.\n\nWhen the main character, Kvothe, tries to explain how sex leads to pregnancy to a woman he's sleeping with, she remains unconvinced. Without the actual science to prove it, nor a general understanding of that science (most people know sex = babies, but not the minutiae of it) he's left with a series of fallacies trying to prove it. Sex leads to babies, but only sometimes. The baby will have traits from both its parents, but not always. A black and a white cat could have sex, and then a bunch of babies would come out as black, white, or both, except for when an orange one pops out.\n\nWithout quoting existing scientific research and trusting the outcome of those scientists, there's almost no way to prove pregnancy is caused by sex.",
"I'm not a doctor in any way... but I think we're forgetting about a pretty solid clue here thats pretty easy to notice. A woman loses her period within 2-3 weeks if pregnant. For 99% of women, that is a MONUMENTAL change that is extremely noticeable and signifies a huge difference. I don't think it would take much to notice that A. I had sex a few weeks ago. Now I don't have my period. I must be pregnant. Or int he very olden day cases, Also, where something like that used to cause a LOT of worry or effort to hide/clean/have a regular life, I think it would stand out to not only the woman in question, but any family that is near them and aware of their rituals. Example. My husband notices when the pad wrappers are in the garbage. Or he knows when I'll be in a mood every month. Not only does it affect the woman, but anyone close and paying attention would notice that as well. Or maybe I'm talking out of my vagina right now...",
"That's like asking how women knew how to feed their newborns. They just did.\n\nYou have to remember that for every species sex, aka procreation, is instinctual. It's not surprising that as our intelligence grew we would be able to put the clues together. Sex has simply been a part of what we do since we've existed.",
"I'd imagine that the resemblance between a the father and his offspring also probably helped to cement the causal link, at least as folks in a tribe \"compared notes.\" This probably really only takes one generation to figure out.",
"Remember that people in the past weren't stupid. They just hadn't built the library of knowledge that we have. Language and writing catapulted humans ahead in a big way.",
"You wouldn't ask that question if you gave ancient civilizations credit for intelligence. The factvis that were cave smart long before we became street smart. ",
"Maybe the discovery that sex led to babies brought our ancestors to the conclusion seeds led to plants. Perhaps the dawn of agriculture happened shortly after the dawn of reproductive awareness, which would put it around 9000BC. ",
"Virgin, virgin, virgin, no baby. Lose virginity, baby. It doesn't take much to figure this out, especially considering things are entering and exiting the same cavity. ",
"You guys are over complicating it. Everyone/everything did it before them. It's not like they thought they were dropped in by aliens.",
"One of the biggest mistakes you can make in history is assuming that past people's mental faculties were lesser than your own.",
"People didn't actually always make the connection. In the trobriand islands people ate a certain yam a lot which lowered their fertility so they could fuck for years before getting pregnant (so they did). They thought pregnancy was unrelated and caused by ghosts.",
"Wow, there are a lot of men in this thread. \n\nSpeaking from personal experience, this is how I'd explain it in the clearest terms possible: \n\nImagine you're a woman in an ancient society. Every month you have to deal with inconvenient, painful, and sometimes dangerous bleeding. You have sex, and then the bleeding stops for a couple months, and you start to notice changes. \n\nThe changes to a woman's pregnant body happen very quickly. When I was pregnant, I knew the first week, even before I took a test. Let's play the devil's advocate and say I knew what to look for. Still, I started feeling violently sick in the mornings the first week, which would also be incredibly inconvenient in an ancient society. Not long after, I had strange cravings for weird foods I wouldn't normally combine. I noticed body changes (tender, larger breasts) after only 2-3 weeks. And after a month I was exhausted all the time. \n\nIf this happened to one woman, in a tiny tribe, once every 3 years, then I can definitely understand how ancient people wouldn't put the puzzle together. But I imagine you're talking about a larger/more complicated society, like a tribe of nomads or even a small village.\n\nCombine that with an idea that perhaps ancient civilizations of that size had a patriarchal hierarchy, and women who were \"unmarried\" (whatever the marital custom might have been) rarely had babies.\n\nI imagine these ideas wouldn't be that hard to piece together seeing as the symptoms would make life very difficult in an ancient society, and pregnant women need more care to survive, even at the very beginning. Women talk to each other about their health, emotions, and sex lives in the modern day, and I imagine it was much the same in ancient times. I'm certain a village with 5-10 births a year would understand the causal relationship, maybe without a perfect understanding of the time frame, but causal nonetheless. ",
"Pretty late to this party, but has anyone mentioned that women know when they're pregnant and might have discussed that with other women?! I knew I was pregnant almost immediately with both of my children. The idea that the effects are delayed is awfully male-centric. ",
"There's cultures today that don't correlate sex with procreation. I need to go look up my old anthro books. Brb ",
"We don't necessarily know that they did. Humans have an inherent urge to have sex, which leads to kids. It's unnecessary for them to know what they were doing in order for the intended effect to occur. ",
"This is really based on my own thoughts, but the whole notion of not knowing what sex is is purely a modern phenomenon. Earlier humans were less concerned about protecting their children from themselves and more concerned about protecting them from predators, so sex was much more casual in the first place. As a result, it was most likely something people just observed and were okay with from the get-go.\n\nAnd it was never that they really cared about the whole \"leads to kids\" thing, that was a byproduct of feeling good: just like how it feels good to eat and sleep, sex was no different.\n\nFast forward thousands of years, and as civilization became more centralized, rules began to be made and eventually sex became subject to religion - causing people to be more self-conscious about sex and their own bodies, evidently leading to it being hidden from children. This is the point you're looking for, as religion tended to slow down or at least organize sex to allow for more direct population control.\n\nConsequentially, today people are too uncomfortable talking about sex to teach it to their own children, so they have to attend special sex-ed classes to learn if they haven't already started watching porn on the internet.\n\n\n",
"It is something that is \"still up for debate\", within the archaeological and anthropological community. It was sort of a new, popular idea that maybe they had no idea and thought that the act of sex and the resulting (maybe) pregnancy were unrelated events. This sparked one of the key themes of the *Earth's Children* series by Jean Auel. Her first book, *Clan of the Cave Bear* is definitely the best, but the theme is more present in the others. This book mostly focuses on the time period when different \"species\" of humans co-existed, but you can see the author is building up to her concept.\n\nTo better answer the question however, the human brain's sense of pattern recognition is one of its strongest traits. While the inconsistency of sex+time=pregnancy could have thrown them off, it is likely that our ancestors had it figured out long before they had language to express the concept. \n\nNeed an example in the animal kingdom (though it is also true in human mothers as well?)? Birds build nests as a prerequisite to becoming a breeding pair. Other animals do it too, making the preparations ahead of time or early on. ",
"The effects aren't really all that delayed. Pregnancy is pretty obvious. Within weeks you start getting morning sickness. You stop getting your period. Then your stomach inflates. Then you feel the baby moving and kicking. Then you give birth. \n\nSo imagine you are an ancient woman. Your day-to-day routine is pretty similar, but then one day you have sex. Within weeks you are sure you are pregnant. The only thing that significantly changed in your life recently was the fact you had sex. \n\nLike, even if you had a group of people who were totally oblivious, it would only take 2 pregnancies before you figured it out."
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3btynm | how come if i am riding alongside another car and look at their spokes sometimes their spokes appear to have stopped or are spinning backwards. | I've noticed this phenomenon with virtually all things that spin and have propellers or blades or spokes. Why does something moving at a high rate of speed suddenly appear to stop or go backward, or still going forwards only much slower? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3btynm/eli5_how_come_if_i_am_riding_alongside_another/ | {
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"This is a stroboscopic effect. What you have not noticed is that it only happens when the light is switched on and off rapidly, as with mercury, xenon, or some fluorescent lights, or when you're not watching with your eye but with a camera, which takes multiple still images of the scene.\n\nThe wheel appears to rotate in ways depending on the interaction of the wheel details and the number of times the light blinks of the camera takes pictures.\n\nIf the light blinks 60 times per second and the wheel rotates 30 times per second, the wheel will appear not to be rotating! If it rotates faster, it appears to spin forward; if it spins slower, it appears to spin backwards. This is something you can see with your eye if the light is truly blinking on and off.\n\nIn the day, the light is constant, so to see this effect you run the wheels at a speed similar to the camera speed. A film camera takes 24 frames per second (fps), video cameras usually take 30 or 60 fps. Regardless, the motion effect depends on the wheels rotating at a speed close to the speed of the camera.\n\nWhat I have never understood is why so many TV ads are made where the wheels appear to spin backwards. That's a distracting detail that looks WRONG. With just a couple more miles per hour, they would appear to spin forward."
]
} | [] | [] | [
[]
] |
|
2s77de | why would elected us legislators spend time and energy writing, debating and voting on any measure that the president has guaranteed he will veto? | The White House has submitted that Pres Obama will absolutely veto any passed measure that continues the Keystone Pipeline. Regardless of the merits or consequences of such a measure, why would legislators, hired by their constituents to effect policy, use their positions to work on anything that is guaranteed to fail? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2s77de/eli5_why_would_elected_us_legislators_spend_time/ | {
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"Veto doesn't mean it will fail. It can be passed regardless of presidential veto with enough votes.",
"They can take something important back to their constituents with an \"I tried to pass this law that was important to you, but the evil president blocked it\". Hopefully increasing support for his preferred presidential candidate. \n\nPlus you can force all sorts of shenanigans by adding it to something optically good (like an anti-child molestation bill or something that the presidents party really, really wants) and watch the president veto it. ",
"It is politics and setting up issues to debate for upcoming elections. The US government is so dysfunctional now that most of what legislators call legislating is debating topics just so they have things to debate when the next election comes around. The delicate art of political compromise to move agendas forward is pretty much dead.",
"Because the veto is not final. We have methods set in place for legislators to re-vote on something and make it law after a veto has been given. ",
"A veto in and of itself is not a guarantee to fail, although it's quite possible in the case of the Keystone Pipeline. \n\nEven assuming the legislation itself failing is considered a forgone conclusion, forcing the President to veto it can show constituents that their representatives are trying to do what they want, and increase pressure on the President. As an example, a current image problem the Republican Party has been dealing with is being painted as 'The Party of No.' By bringing forward legislation that the President will veto, they will likely portray him as engaging in the same practice. \n\nTo some degree, it is simply a strategy for changing image, but image matters in politics. ",
"So they can blame the president for the failure to get anything done.",
"It's partly politics and partly the system.\n\nPolitics plays an important role in the veto process. Even though they know it will it get vetoed, they push it because they force the President to make a stand - and usually they'll throw some riders that the President would really want on to the bill so he'll have to veto that too. They can then do two things:\n\n1. They can say to their constituents, \"I wanted this and your president is totally against it.\" \n\n2. The can say, \"Look, this bill was vetoed but is does all this good for the country...\" This would be the riders that also got vetoed, making the president look really bad.\n\nIt's partly the system. The system is designed to allow the president to veto any bill, sending it back to the senate and house. However, congress can override the President by voting on it again. If they (teh bill's makers) have the majority in both Senate and the House, it's very possible they can override the bill and make it a law. The veto is just a step in the process and one that must be dealt with.\n\nSo even though they know the veto will happen, they can still pass the law after that. \n\nSo politically, it's very easy to make the president look bad when he vetoes a bill and by the system, the veto is just one step to making a bill a law.",
"If they vote on it they have clear evidence that they wanted to enact policy X and their opponents did not.\n\nIf you support X then this is a good way to get your vote. It also is a good way to pressure the president to change his position, as you're putting him on the spot. It might not force him to change his position, but maybe it'll influence the next presidential election. If you care about X deeply then you'll want a president in office who supports that, and having a vote puts everyone's position out in the public eye."
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364pu2 | how do phone/laptop chargers take ac power and convert it to dc? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/364pu2/eli5_how_do_phonelaptop_chargers_take_ac_power/ | {
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"There is a circuit composed of diodes that performs the conversion. It's called a [rectifier](_URL_0_).\n\nBasically, when the AC current goes one way, it passes through unchanged, and when it goes the other way, the rectifier either flips the current around, or just blocks it entirely. That way, the current at the output only ever goes one way.\n\nNow, with regards to cell phones and laptops, they all actually take DC power. The charger for the device has the rectifier in it, so the power coming into the charging port of the device is already DC.",
"They use a device called a \"rectifier.\" A rectifier exploits the fact that diodes only allow current to flow in one direction to produce a DC voltage from an AC one.\n\nA rectifier circuit looks like [this](_URL_0_). On the left you have your AC voltage source, like a power outlet. In the middle is the diode, and on the right is the load, which would be your battery.\n\nIf the voltage is positive, current will flow through the diode to the right. This puts a positive voltage on the battery.\n\nIf the voltage is negative, current would *like* to flow to the left, but diodes only allow current to flow in one direction. So, the current is blocked, and nothing happens. The negative voltage is thus cut off, and the battery will only receive power while the source is at positive voltage.\n\nThe problem with this design is that voltage only hits the battery half the time, which is kind of inefficient. A more complex rectifier setup is the [bridge rectifier](_URL_1_). The red arrows show the flow of current when the voltage source (IN) is positive, and the blue ones show the flow of current when the source is negative. Either way, the DC output (OUT) always has current flowing from + to -, so we have full-time DC power.\n\nRectifiers will also include components like step-down transformers and smoothing capacitors, but we don't really need to worry about those."
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/Rectifier"
],
[
"http://www.radio-electronics.com/info/circuits/diode-rectifier/diode-rectifier-half-wave-concept.gif",
"http://i.imgur.com/QTbkUR1.png"
]
] |
||
8lz9k3 | what was the surgery to become an eunuch in ancient and medieval china like? and during that time, medicine, antibiotics and such hasn’t really developed yet, how do they recover? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8lz9k3/elif_what_was_the_surgery_to_become_an_eunuch_in/ | {
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"Both the testicles and penis were cut off with a knife at the same time. The knife was sterilized with fire before the procedure and the wound cleaned with a hot pepper soup afterwards to prevent infection. The wound would then heal as a normal wound would.. or wouldn't. Sometimes people would just die from the procedure.\n\nAnother way to produce a eunuch would be from birth. A special nanny would squeeze the reproductive organs three times a day, gradually increasing pressure which would eventually destroy them and they would shrink, along with the development of female characteristics in the child.",
"There's a really detailed explanation in r/Askhistorians by someone who is an expert in eunuchs. In some areas, eunuchs had the testicles removed. That was the more common procedure, and there's a long history of doing that with animals, too. To remove the penis also had a much higher rate of mortality so it was less commonly done."
]
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